The Relationship of Body Length and Ratio Pappilla with Sex in Gobi Fish (Sicyopterus macrostetholepis

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Rona Taula Sari

2017-07-01

Full Text Available Research about the relationship of body length and ratio papilla with sex in goby fish (S. macrostetholepis Blkr. has been done at Animal Structure and Developmental Laboratory, Biologi Department, Faculty of Matematics and Natural Sciences, Andalas University, Padang, which purposed to analyse the relationship of body length and ratio papilla with sex of goby fish (S. macrostetholepis Blkr.. The samples were taken in wild stream area at Batangkuranji river, Padang City. This research used descriptive method and data were analyzed by qualitatively and quantitatively. The results of investigation showed that in several goby fishes (S. macrostetholepis Blkr. with different sex had the same of body length and the same of ratio papilla. So, there was not relationship between of body length and ratio papilla with sex.  Goby fishes (S. macrostetholepis Blkr. it belongs to the hermaphrodite protogini, which the androgynous young females, while in adulthood, it would change sex to male. The results of this study are expected to add to the treasures of knowledge and information about reproductive gobies (S. macrostetholepis Blkr. in the preservation and development of fish farming.   

The diet of reservoir perch before, during and after establishment of non-native tubenose goby

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Všetičková Lucie

2018-01-01

Full Text Available In recent decades, gobiid species have increased their distribution throughout Europe and now often represent the dominant genus along many rivers and canals. In this study, we assessed the role of tubenose goby (Proterorhinus semilunaris as a prey species of native perch (Perca fluviatilis in a lowland reservoir soon after their initial introduction in 1994 (sampling started 1998 and 17 years after establishment (2011–2012. We compare these data with perch diet composition from before introduction (1981–1982. Our data indicate that tubenose gobies quickly became the dominant species along the reservoir bankside, making them an attractive prey for ≥1 + perch. There was a clear increasing trend in the numbers of larger perch caught along the rip-rap, with the largest fish clearly specialising on gobies. As such, introduction of tubenose gobies has had a pronounced effect on food web and population dynamics along the littoral zone. While goby numbers appear to have dropped significantly in recent years, apparently due to predation pressure, further studies are needed to assess whether such changes have had any general impact on population and food web dynamics within the reservoir.

Study of the microwave emissivity characteristics over Gobi Desert

International Nuclear Information System (INIS)

Yubao, Qiu; Lijuan, Shi; Wenbo, Wu

2014-01-01

The microwave emissivity represents the capacity of the thermal radiation of the surface, and it is the significant parameter for understanding the geophysical processes such as surface energy budget and surface radiation. Different land covers have different emissivity properties, and the Gobi Desert in Central Asia seriously impact the sandstorms occur and develop in China, because of its special geographical environment and surface soil characteristics. In this study half-month averaged microwave emissivity from March 2003 to February 2004 over the Gobi Desert has been estimated. Emissivities in this area at different frequencies, polarization and their seasonal variations are discussed respectively. The results showed that emissivity polarization difference decrease as the frequency increases, and the polarization difference is large (0.03–0.127). The H polarization emissivity increases with increasing frequency, but the V-polarized microwave emissivity is reduced with increasing frequency because of the body scattering. In winter, emissivity decreases sharply in snow covered area, especially for higher frequencies (such as 89GHz). In addition, we compared emissivity with MODIS NDVI data at the same time in the Gobi Desert, and the results indicate that NDVI derived the good negative correlation with microwave emissivity polarization difference at 37GHz

Environmental DNA (eDNA): A tool for quantifying the abundant but elusive round goby (Neogobius melanostomus)

Science.gov (United States)

Nevers, Meredith; Byappanahalli, Muruleedhara; Morris, Charles C.; Shively, Dawn; Przybyla-Kelly, Katarzyna; Spoljaric, Ashley M.; Dickey, Joshua; Roseman, Edward

2018-01-01

Environmental DNA (eDNA) is revolutionizing biodiversity monitoring, occupancy estimates, and real-time detections of invasive species. In the Great Lakes, the round goby (Neogobius melanostomus), an invasive benthic fish from the Black Sea, has spread to encompass all five lakes and many tributaries, outcompeting or consuming native species; however, estimates of round goby abundance are confounded by behavior and habitat preference, which impact reliable methods for estimating their population. By integrating eDNA into round goby monitoring, improved estimates of biomass may be obtainable. We conducted mesocosm experiments to estimate rates of goby DNA shedding and decay. Further, we compared eDNA with several methods of traditional field sampling to compare its use as an alternative/complementary monitoring method. Environmental DNA decay was comparable to other fish species, and first-order decay was lower at 12°C (k = 0.043) than at 19°C (k = 0.058). Round goby eDNA was routinely detected in known invaded sites of Lake Michigan and its tributaries (range log10 4.8–6.2 CN/L), but not upstream of an artificial fish barrier. Traditional techniques (mark-recapture, seining, trapping) in Lakes Michigan and Huron resulted in fewer, more variable detections than eDNA, but trapping and eDNA were correlated (Pearson R = 0.87). Additional field testing will help correlate round goby abundance with eDNA, providing insight on its role as a prey fish and its impact on food webs.

Fries' goby, a European oddity

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Peter J Miller

2015-12-01

Full Text Available Fries' Goby, Lesueurigobius friesii (Malm, 1874 is common on softer grounds of the more offshore eastern Atlantic continental shelf from Norway to Mauritania, and in the Mediterranean to the Sea of Marmora. The several species of the genus are unique among Lusitanian/Boreal gobiine gobies in coloration and caudal morphology as well as in the 'longitudinal' pattern of infraorbital free neuromast-organs and the lack of head lateral-line canals. A new classification of Old World longitudinal gobiines, based on these free neuromast patterns of both infraorbital and hyomandibular innervation, places Lesueurigobius as the Atlantic sister group to the other longitudinal gobiines, which are all Indo/West Pacific in distribution. The proposed cladogram, the first for the group, is based on synapomorphies in features of rostral mandibular line neuromast series f, the rows of the cheek, and vertebral number. Species of Lesueurigobius show an apparently apomorphic reduction in infraorbital row cp that is shared with three Indo-West Pacific genera (Silhouettea, Heteroplopomus and Platygobiopsis but, in Lesueurigobius , this is now believed to be plesiomorphic. Morphological character states were used to construct a cladogram which was discussed in relation to molecular findings that support Lesueurigobius as an outgroup to the Indo/West Pacific genera. The importance of the latter as tools for testing morphological phylogenies, rather than as conflicting classification, is strongly emphasised.

Tetrodotoxin poisoning caused by Goby fish consumption in southeast China: a retrospective case series analysis

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Jie You

2015-01-01

Full Text Available OBJECTIVES: To investigate an unusual outbreak of tetrodotoxin poisoning in Leizhou, southeast China, a case series analysis was conducted to identify the source of illness. METHODS: A total of 22 individuals experienced symptoms of poisoning, including tongue numbness, dizziness, nausea and limb numbness and weakness. Two toxic species, Amoya caninus and Yongeichthys nebulosus, were morphologically identified from the batches of gobies consumed by the patients. Tetrodotoxin levels in the blood and Goby fish samples were detected using liquid chromatography-tandem mass spectrometry. RESULTS: The tetrodotoxin levels in the remaining cooked Goby fish were determined to be 2090.12 µg/kg. For Amoya caninus, the toxicity levels were 1858.29 µg/kg in the muscle and 1997.19 µg/kg in the viscera and for Yongeichthys nebulosus, they were 2783.00 µg/kg in the muscle and 2966.21 µg/kg in the viscera. CONCLUSION: This outbreak demonstrates an underestimation of the risk of Goby fish poisoning. Furthermore, the relationships among the toxic species, climates and marine algae present should be clarified in the future.

Invasion strategies in round goby (Neogobius melanostomus: Is bigger really better?

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Joerg Brandner

Full Text Available Few studies have systematically investigated mid- or long-term temporal changes of biological characteristics in invasive alien species considering the different phases of an invasion. We studied the invasion performance of one of the most invasive species worldwide, the round goby Neogobius melanostomus, from total absence over first occurrence until establishment from 2010 to 2015 in the upper Danube River. After an upstream movement of the invasion front of about 30 river km within four years, the pattern that round goby pioneering populations significantly differ from longer established ones has been confirmed: Pioneering populations at the invasion front comprised more females than males, and adult specimens with a larger body size compared to those at longer inhabited areas. On the population-level, the proportion of juveniles increased with time since invasion. The results of this study provide support for the previously postulated ´bigger is better´ and ´individual trait utility´ hypotheses explaining invasion success in round goby. Pioneering invaders with their greater exploratory behavior, highly adaptive phenotypic plasticity and increased competitive ability seem to act as prime emperors of new habitats, strongly following and benefiting from man-made river-bank structures.

KINESIOLOGY- THE SCIENCE OF MOVEMENT In Relation to Education, Hygiene and Therapy. A piece of the legacy of Nicolas Dally (1795-1862 for contemporary kinesiology scholars and professionals

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Franjo Prot

2010-01-01

Full Text Available Kinesiology has recently gained full worldwide credibility as an academic discipline in the field of human movement and exercise practice in the area of education, sport, recreation and kinesitherapy, becoming a proper denominator for the field of sport or exercise science. It seems almost compulsory that on the occasion of the introduction of the first issue of Annales Kinesiologiae, a new scientific journal in the field, to remember and speak about Nicolas Dally and his work. In this paper a short biography of the forefather of KINESIOLOGY, or CINÉSIOLOGIE, will be presented as well as how Dally introduced the term and the concept in his book from 1857. It is presented and integrated with some newly available illustrative material. Dally’s bibliography based on resources of worldwide relevant library catalogues is added to the references.

INVASION OF ROUND GOBY NEOGOBIUS MELANOSTOMUS (PALLAS, 1814 – ECO-THREAT OR ENVIROMENTAL ENRICHMENT?

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Katarzyna Stepanowska

2014-10-01

Full Text Available Round goby Neogobius melanostomus (Pallas, 1814 is a fish species of Ponto-Caspian basin origin. However, since the second part of the 80’s of the last century has observed spreading of this species in European waters, including in Polish waters. In the last two decades, from 1990 when it was first caught of round goby near the fishing port in Hel, takes a massive and rapid spread of this fish throughout the Gulf of Gdańsk, Vistula Lagoon, along the southern Baltic coastal zone and the Pomeranian Bay and also the River Odra estuary. In 2009, first round goby in commercial catches conducted in Lake Dąbie was recorded. In this situation the question is that invasion can be a eco-threat or even enrichment of the environment to the human being?

基于决策树的戈壁信息提取研究%Gobi information extraction based on decision tree classification method

Institute of Scientific and Technical Information of China (English)

冯益明; 智长贵; 姚爱冬

2013-01-01

Gobi is one of the main landscape types of earth' s surface in the arid region of northwestern parts of China, with the total area of 458 000-757 000 km2, accounting for the 4.8%-7.9% of China's total land area. The gobi holds abundant natural resources such as minerals, wind energy and solar power. Meanwhile, many modern cities and towns and some important traffic routes were also constructed on the gobi region. The gobi region plays an important role in the construction of western economy. Therefore, it is important to launch the gobi research under current social and economic conditions, and accurately revealing the distribution and area of gobi is the base and premise of launching the gobi research. At present, it is difficult to do fieldwork due to the execrable natural conditions and the sparse dweller in the gobi region, which leads to the scarcity of research documents on the situation, distribution, type classification, transformation and utilization of gobi. The studied region of this paper is a typical gobi distribution region, locating in Ejina County in Inner Mongolia, China, and its climatic characteristics include lack of rain, more evaporation, full sunshine, large temperature difference and frequent windy sand weather. Using Remote Sensing imageries Landsat TM5 and TM7 of plant growth season of 2005-2010, the DEM with 30 m spatial resolution, administrative map, present land use map, field investigation data and related documents as the basic data resource. Firstly, the non-gobi distribution regions were extracted in GIS software by analyzing DEM. Then, based on the analysis of spectral characteristics of difference typical ground objects, the information extraction model of Decision Tree based on knowledge was constructed to classify the remote sensing imageries, and eroded gobi and cumulated gobi were relatively accurately separated. The general accuracy of the extracted gobi information reached 91.57%. There were few materials in China on using

Hydrothermal Fluid evolution in the Dalli porphyry Cu-Au Deposit: Fluid Inclusion microthermometry studies

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Alireza Zarasvandi

2015-10-01

Full Text Available Introduction A wide variety of world-class porphyry Cu deposits occur in the Urumieh-Dohktar magmatic arc (UDMA of Iran.The arc is composed of calc-alkaline granitoid rocks, and the ore-hosting porphyry intrusions are dominantly granodiorite to quartz-monzonite (Zarasvandi et al., 2015. It is believed that faults played an important role in the emplacement of intrusions and subsequentporphyry-copper type mineralization (Shahabpour, 1999. Three main centers host the porphyry copper mineralization in the UDMA: (1 Ardestan-SarCheshmeh-Kharestan zone, (2 Saveh-Ardestan district; in the central parts of the UDMA, hosting the Dalli porphyry Cu-Au deposit, and (3 Takab-Mianeh-Qharahdagh-Sabalan zone. Mineralized porphyry coppersystems in the UDMA are restricted to Oligocene to Mioceneintrusions and show potassic, sericitic, argillic, propylitic and locally skarn alteration (Zarasvandi et al., 2005; Zarasvandi et al., 2015. In the Dalli porphyry deposit, four hydrothermal alteration zones, includingpotassic, sericitic, propylitic, and argillic types have been described in the two discrete mineralized areas, namely, northern and southern stocks. Hypogenemineralization includes chalcopyrite, pyrite, and magnetite, with minor occurrences of bornite.Supergene activity has produced gossan, oxidized minerals and enrichment zones. The supergene enrichment zone contains chalcocite and covellite with a 10-20 m thickness. Mineralization in the northern stock is mainly composed of pyrite and chalcopyrite. The aim of this study is the investigation and classification of hydrothermal veins and the constraining of physicochemical compositions of ore-forming fluids using systematic investigation of fluid inclusions. Materials and methods Twenty samples were collected from drill holes. Thin and polished sections were prepared from hydrothermal veins of thepotassic, sericitic and propylitic alteration zones. Samples used for fluid inclusion measurements were collected

Lithospheric controls on crustal reactivation and intraplate mountain building in the Gobi Corridor, Central Asia

Science.gov (United States)

Cunningham, D.

2017-12-01

This talk will review the Permian-Recent tectonic history of the Gobi Corridor region which includes the actively deforming Gobi Altai-Altai, Eastern Tien Shan, Beishan and North Tibetan foreland. Since terrane amalgamation in the Permian, Gobi Corridor crust has been repeatedly reactivated by Triassic-Jurassic contraction/transpression, Late Cretaceous extension and Late Cenozoic transpression. The tectonic history of the region suggests the following basic principle for intraplate continental regions: non-cratonized continental interior terrane collages are susceptible to repeated intraplate reactivation events, driven by either post-orogenic collapse and/or compressional stresses derived from distant plate boundary convergence. Thus, important related questions are: 1) what lithospheric pre-conditions favor intraplate crustal reactivation in the Gobi Corridor (simple answer: crustal thinning, thermal weakening, strong buttressing cratons), 2) what are the controls on the kinematics of deformation and style of mountain building in the Gobi-Altai-Altai, Beishan and North Tibetan margin (simple answer: many factors, but especially angular relationship between SHmax and `crustal grain'), 3) how does knowledge of the array of Quaternary faults and the historical earthquake record influence our understanding of modern earthquake hazards in continental intraplate regions (answer: extrapolation of derived fault slip rates and recurrence interval determinations are problematic), 4) what important lessons can we learn from the Mesozoic-Cenozoic tectonic history of Central Asia that is applicable to the tectonic evolution of all intraplate continental regions (simple answer: ancient intraplate deformation events may be subtly expressed in the rock record and only revealed by low-temperature thermochronometers, preserved orogen-derived sedimentary sequences, fault zone evidence for younger brittle reactivation, and recognition of a younger class of cross-cutting tectonic

Characterization of vitellogenin gene expression in round goby (Neogobius melanostomus) using a quantitative polymerase chain reaction assay.

Science.gov (United States)

Bowley, Lucas A; Alam, Farhana; Marentette, Julie R; Balshine, Sigal; Wilson, Joanna Y

2010-12-01

A growing concern over endocrine disruption in aquatic species has prompted the development of molecular assays to monitor environmental impacts. This study describes the development of quantitative polymerase chain reaction (qPCR) assays to characterize the expression of two vitellogenin (Vtg) genes in the invasive round goby (Neogobius melanostomus). Fragments from the 18SrRNA (housekeeping gene), Vtg II, and Vtg III genes were cloned and sequenced. The qPCR assays were developed to detect hepatic Vtg expression in goby. The assays detected induction of both Vtg genes in nonreproductive males following a two-week laboratory exposure to 17β-estradiol (≥1 mg/kg i.p. injection). The assays were applied to goby from Hamilton Harbour, Lake Ontario (Canada), including those from sites where feminization and intersex of goby has been documented. Both Vtg genes had significantly higher expression in females compared to males. Male reproductive goby adopt either parental or sneaker tactics; Vtg II expression was higher in sneaker than in parental males but parental and nonreproductive males did not differ from each other. The Vtg III expression was significantly higher in sneaker males followed by parental males and nonreproductive males, respectively. The Vtg II and III expression in nonreproductive males was elevated in the contaminated site with documented intersex. This assay provides an important tool for the use of an invasive species in monitoring endocrine disruption in the Great Lakes region. Copyright © 2010 SETAC.

Invasion rate and population characteristics of the invasive round goby Neogobius melanostomus: effects of density and invasion history

DEFF Research Database (Denmark)

Azour, Farivar; Deurs, Mikael van; Behrens, Jane

2015-01-01

Round goby Neogobius melanostomus is currently one of the most wide-ranging invasive fish species in Europe and North America. The present study demonstrates how the distribution of round goby has expanded from 2008 to 2013 at a rate of about 30 km yr−1 along the Danish coastline in the western B...

Every drop counts: Interview with awardee Gabin Koto N'Gobi ...

International Development Research Centre (IDRC) Digital Library (Canada)

2012-05-11

May 11, 2012 ... While artificial dew collection methods already exist, Koto N'Gobi ... The good news is that the condenser harvests up to 4L of water per ... “For example, at the Guene primary school, there is no water point for the students.

Phylogeny of Gobioidei and the origin of European gobies

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Ainhoa Agorreta

2015-11-01

Full Text Available The percomorph order Gobioidei comprises over 2200 species worldwide distributed that occupy most freshwater, brackish and marine environments, and show a spectacular variety in morphology, ecology, and behaviour. However, phylogenetic relationships among many gobioid groups still remain poorly understood. Such is the case of Gobiidae, a rapidly radiating lineage that encompass an unusually high diversity of species (nearly 2000, including the largely endemic European species whose origin and ancestry remain uncertain. The resolution and accuracy of previous molecular phylogenetic studies has been limited due to the use of only a few (generally mitochondrial molecular markers and/or the absence of representatives of several key lineages. Our study (built on Agorreta et al. 2013 is the first to include multiple nuclear and mitochondrial genes for nearly 300 terminal taxa representing the vast diversity of gobioid lineages. We have used this information to reconstruct a robust phylogeny of Gobioidei, and we are now investigating the historical biogeography and diversification times of European gobies with a time-calibrated molecular phylogeny. Robustness of the inferred phylogenetic trees is significantly higher than that of previous studies, hence providing the most compelling molecular phylogenetic hypotheses for Gobioidei thus far. The family Eleotrididae branches off the gobioid tree after the Rhyacichthyidae + Odontobutidae clade followed by the Butidae as the sister-group of the Gobiidae. Several monophyletic groups are identified within the two major Gobiidae subclades, the gobionelline-like and the gobiine-like gobiids. The European gobies cluster in three distinct lineages (Pomatoschistus-, Aphia-, and Gobius-lineages, each with different affinities with gobiids from the Indo-Pacific and perhaps the New World. Our ongoing more-detailed study on European gobies will reveal whether their origin is related to vicariant events linked to the

Urban particle size distributions during two contrasting dust events originating from Taklimakan and Gobi Deserts

International Nuclear Information System (INIS)

Zhao, Suping; Yu, Ye; Xia, Dunsheng; Yin, Daiying; He, Jianjun; Liu, Na; Li, Fang

2015-01-01

The dust origins of the two events were identified using HYSPLIT trajectory model and MODIS and CALIPSO satellite data to understand the particle size distribution during two contrasting dust events originated from Taklimakan and Gobi deserts. The supermicron particles significantly increased during the dust events. The dust event from Gobi desert affected significantly on the particles larger than 2.5 μm, while that from Taklimakan desert impacted obviously on the particles in 1.0–2.5 μm. It is found that the particle size distributions and their modal parameters such as VMD (volume median diameter) have significant difference for varying dust origins. The dust from Taklimakan desert was finer than that from Gobi desert also probably due to other influencing factors such as mixing between dust and urban emissions. Our findings illustrated the capacity of combining in situ, satellite data and trajectory model to characterize large-scale dust plumes with a variety of aerosol parameters. - Highlights: • Dust particle size distributions had large differences for varying origins. • Dust originating from Taklimakan Desert was finer than that from Gobi Desert. • Effect of dust on the supermicron particles was obvious. • PM_1_0 concentrations increased by a factor of 3.4–25.6 during the dust event. - Dust particle size distributions had large differences for varying origins, which may be also related to other factors such as mixing between dust and urban emissions.

Non-native gobies facilitate the transmission of Bucephalus polymorphus (Trematoda)

Czech Academy of Sciences Publication Activity Database

Ondračková, Markéta; Hudcová, Iveta; Dávidová, Martina; Adámek, Zdeněk; Kašný, M.; Jurajda, Pavel

2015-01-01

Roč. 8, č. 1 (2015), s. 382 ISSN 1756-3305 R&D Projects: GA ČR(CZ) GAP505/12/2569 Institutional support: RVO:68081766 Keywords : Bucephalus polymorphus * Complex life cycle * Goby * Infectivity * Intermediate host * Non-native species * Trematode Subject RIV: EH - Ecology, Behaviour Impact factor: 3.234, year: 2015

Study of food habits of Goby, Porogobius schlegelii (Gunther, 1861 ...

African Journals Online (AJOL)

The study examines the food habits of goby, Porogobius schelgelii from the artisanal fisheries of the Bonny River in the Niger Delta. The results show that detritus, diatoms and blue-green algae are the primary food items followed by sand granules, macrophytes and nematodes as secondary food items. Protozoa. Fish eggs ...

Environment not "nativeness" dictates reproductive trait shifts in Ponto-Caspian gobies

Czech Academy of Sciences Publication Activity Database

Konečná, Markéta; Janáč, Michal; Roche, Kevin Francis; Jurajda, Pavel

2016-01-01

Roč. 25, č. 1 (2016), s. 167-170 ISSN 0906-6691 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Pseudorasbora parva * invasive plants * populations * invader * range * goby Subject RIV: EG - Zoology Impact factor: 2.054, year: 2016

First stable isotope analysis of Asiatic wild ass tail hair from the Mongolian Gobi.

Science.gov (United States)

Horacek, Micha; Sturm, Martina Burnik; Kaczensky, Petra

Stable isotope analysis has become a powerful tool to study feeding ecology, water use or movement pattern in contemporary, historic and ancient species. Certain hair and teeth grow continuously, and when sampled longitudinally can provide temporally explicit information on dietary regime and movement pattern. In an initial trial, we analysed a tail sample of an Asiatic wild ass ( Equus hemionus ) from the Mongolian Gobi. We found seasonal variations in H, C and N isotope patterns, likely being the result of temporal variations in available feeds, water supply and possibly physiological status. Thus stable isotope analysis shows promise to study the comparative ecology of the three autochthonous equid species in the Mongolian Gobi.

Twenty five years of invasion: management of the round goby Neogobius melanostomus in the Baltic Sea

DEFF Research Database (Denmark)

Ojaveer, Henn; Galil, Bella S.; Lehtiniemi, Maiju

2015-01-01

The round goby, Neogobius melanostomus (Pallas, 1814), is one of the most invasive non-indigenous species in the Baltic Sea. It dominates coastal fisheries in some localities and is frequently found in offshore pelagic catches. This paper identifies management issues and suggests actions to be co......The round goby, Neogobius melanostomus (Pallas, 1814), is one of the most invasive non-indigenous species in the Baltic Sea. It dominates coastal fisheries in some localities and is frequently found in offshore pelagic catches. This paper identifies management issues and suggests actions...... to be considered for post-invasion management. Priority should be given to the establishment of a coordinated pan-Baltic monitoring programme and associated data storage and exchange, as well as the compilation of landing statistics of the round goby in commercial and recreational fisheries. While eradication...... is unrealistic, population control that leads to minimising the risk of transfer to yet uncolonised areas in the Baltic Sea and adjacent waterbodies is feasible. This should comprise the requirement that the species be landed in commercial fishery bycatch, the management of ships’ ballast water and sediments...

Satellite Monitoring of Vegetation Response to Precipitation and Dust Storm Outbreaks in Gobi Desert Regions

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Yuki Sofue

2018-02-01

Full Text Available Recently, droughts have become widespread in the Northern Hemisphere, including in Mongolia. The ground surface condition, particularly vegetation coverage, affects the occurrence of dust storms. The main sources of dust storms in the Asian region are the Taklimakan and Mongolian Gobi desert regions. In these regions, precipitation is one of the most important factors for growth of plants especially in arid and semi-arid land. The purpose of this study is to clarify the relationship between precipitation and vegetation cover dynamics over 29 years in the Gobi region. We compared the patterns between precipitation and Normalized Difference Vegetation Index (NDVI for a period of 29 years. The precipitation and vegetation datasets were examined to investigate the trends during 1985–2013. Cross correlation analysis between the precipitation and the NDVI anomalies was performed. Data analysis showed that the variations of NDVI anomalies in the east region correspond well with the precipitation anomalies during this period. However, in the southwest region of the Gobi region, the NDVI had decreased regardless of the precipitation amount, especially since 2010. This result showed that vegetation in this region was more degraded than in the other areas.

Zebra mussel beds: an effective feeding ground for Ponto-Caspian gobies or suitable shelter for their prey?

Science.gov (United States)

Kobak, Jarosław; Poznańska, Małgorzata; Jermacz, Łukasz; Kakareko, Tomasz; Prądzynski, Daniel; Łodygowska, Małgorzata; Montowska, Karolina; Bącela-Spychalska, Karolina

2016-01-01

Aggregations of the Ponto-Caspian invasive zebra mussel ( Dreissena polymorpha ) constitute a suitable habitat for macroinvertebrates, considerably increasing their abundance and providing effective antipredator protection. Thus, the overall effect of a mussel bed on particular predator species may vary from positive to negative, depending on both prey density increase and predator ability to prey in a structurally complex habitat. Alien Ponto-Caspian goby fish are likely to be facilitated when introduced into new areas by zebra mussels, provided that they are capable of utilizing mussel beds as habitat and feeding grounds. We ran laboratory experiments to find which prey (chironomid larvae) densities (from ca. 500 to 2,000 individuals m -2 ) in a mussel bed make it a more beneficial feeding ground for the racer goby Babka gymnotrachelus (RG) and western tubenose goby Proterorhinus semilunaris (WTG) compared to sandy and stone substrata (containing the basic prey density of 500 ind. m -2 ). Moreover, we checked how food availability affects habitat selection by fish. Mussel beds became more suitable for fish than alternative mineral substrata when food abundance was at least two times higher (1,000 vs. 500 ind. m -2 ), regardless of fish size and species. WTG was associated with mussel beds regardless of its size and prey density, whereas RG switched to this habitat when it became a better feeding ground than alternative substrata. Larger RG exhibited a stronger affinity for mussels than small individuals. WTG fed more efficiently from a mussel bed at high food abundances than RG. A literature review has shown that increasing chironomid density, which in our study was sufficient to make a mussel habitat an attractive feeding ground for the gobies, is commonly observed in mussel beds in the field. Therefore, we conclude that zebra mussels may positively affect the alien goby species and are likely to facilitate their establishment in novel areas, contributing to an

Zebra mussel beds: an effective feeding ground for Ponto-Caspian gobies or suitable shelter for their prey?

Directory of Open Access Journals (Sweden)

Jarosław Kobak

2016-11-01

Full Text Available Aggregations of the Ponto-Caspian invasive zebra mussel (Dreissena polymorpha constitute a suitable habitat for macroinvertebrates, considerably increasing their abundance and providing effective antipredator protection. Thus, the overall effect of a mussel bed on particular predator species may vary from positive to negative, depending on both prey density increase and predator ability to prey in a structurally complex habitat. Alien Ponto-Caspian goby fish are likely to be facilitated when introduced into new areas by zebra mussels, provided that they are capable of utilizing mussel beds as habitat and feeding grounds. We ran laboratory experiments to find which prey (chironomid larvae densities (from ca. 500 to 2,000 individuals m−2 in a mussel bed make it a more beneficial feeding ground for the racer goby Babka gymnotrachelus (RG and western tubenose goby Proterorhinus semilunaris (WTG compared to sandy and stone substrata (containing the basic prey density of 500 ind. m−2. Moreover, we checked how food availability affects habitat selection by fish. Mussel beds became more suitable for fish than alternative mineral substrata when food abundance was at least two times higher (1,000 vs. 500 ind. m−2, regardless of fish size and species. WTG was associated with mussel beds regardless of its size and prey density, whereas RG switched to this habitat when it became a better feeding ground than alternative substrata. Larger RG exhibited a stronger affinity for mussels than small individuals. WTG fed more efficiently from a mussel bed at high food abundances than RG. A literature review has shown that increasing chironomid density, which in our study was sufficient to make a mussel habitat an attractive feeding ground for the gobies, is commonly observed in mussel beds in the field. Therefore, we conclude that zebra mussels may positively affect the alien goby species and are likely to facilitate their establishment in novel areas

McGET: A rapid image-based method to determine the morphological characteristics of gravels on the Gobi desert surface

Science.gov (United States)

Mu, Yue; Wang, Feng; Zheng, Bangyou; Guo, Wei; Feng, Yiming

2018-03-01

The relationship between morphological characteristics (e.g. gravel size, coverage, angularity and orientation) and local geomorphic features (e.g. slope gradient and aspect) of desert has been used to explore the evolution process of Gobi desert. Conventional quantification methods are time-consuming, inefficient and even prove impossible to determine the characteristics of large numbers of gravels. We propose a rapid image-based method to obtain the morphological characteristics of gravels on the Gobi desert surface, which is called the "morphological characteristics gained effectively technique" (McGET). The image of the Gobi desert surface was classified into gravel clusters and background by a machine-learning "classification and regression tree" (CART) algorithm. Then gravel clusters were segmented into individual gravel clasts by separating objects in images using a "watershed segmentation" algorithm. Thirdly, gravel coverage, diameter, aspect ratio and orientation were calculated based on the basic principles of 2D computer graphics. We validated this method with two independent datasets in which the gravel morphological characteristics were obtained from 2728 gravels measured in the field and 7422 gravels measured by manual digitization. Finally, we applied McGET to derive the spatial variation of gravel morphology on the Gobi desert along an alluvial-proluvial fan located in Hami, Xinjiang, China. The validated results show that the mean gravel diameter measured in the field agreed well with that calculated by McGET for large gravels (R2 = 0.89, P < 0.001). Compared to manual digitization, the McGET accuracies for gravel coverage, gravel diameter and aspect ratio were 97%, 83% and 96%, respectively. The orientation distributions calculated were consistent across two different methods. More importantly, McGET significantly shortens the time cost in obtaining gravel morphological characteristics in the field and laboratory. The spatial variation results

Cleaning interactions by gobies on a tropical eastern Pacific coral reef.

Science.gov (United States)

Quimbayo, J P; Zapata, F A

2018-04-01

The present study describes the cleaning interactions among species of cleaner gobies Tigrigobius spp. and Elacatinus puncticulatus (family Gobiidae) and the client fish species they clean in a coral reef of Gorgona Island, Colombia. In 419 cleaning events, we observed 27 species acting as clients of Tigrigobius spp., whereas only nine were clients of E. puncticulatus. Paranthias colonus and Cephalopholis panamensis were the species most commonly cleaned by Tigrigobius spp., while Ophioblennius steindachneri and Stegastes acalpulcoensis were the clients most commonly cleaned by E. puncticulatus. The abundance (but not the body size) of clients was an important variable predicting the cleaning frequency observed for clients of Tigrigobius spp., but this was not the case for clients of E. puncticulatus. Additionally, Tigrigobius spp. preferred cleaning planktivores, sessile invertebrate feeders and territorial herbivores (Ivlev's index >0·15), whereas E. puncticulatus did not exhibit any preference. We observed two major peaks of cleaning activity for Tigrigobius spp., one in the early morning and another one in the late afternoon. These results suggest that Tigrigobius spp. is a specialized cleaner goby, whereas E. puncticulatus is a facultative cleaner that cleans sporadically. © 2018 The Fisheries Society of the British Isles.

Pastoral community organization, livelihoods and biodiversity conservation in Mongolia's Southern Gobi Region

Science.gov (United States)

Sabine M. Schmidt

2006-01-01

In this paper I describe processes and impacts of collective action by mobile pastoralist communities, and of external support strategies to strengthen local institutions and cooperation in Mongolia’s southern Gobi. The need for pastoral mobility triggered the processes leading to community organization, and the emergence, or re-emergence, of local informal...

Water and vapor transfer in vadose zone of Gobi desert and riparian in the hyper arid environment of Ejina, China

Science.gov (United States)

Du, C.; Yu, J.; Sun, F.; Liu, X.

2015-12-01

To reveal how water and vapor transfer in vadose zone affect evapotranspiration in Gobi desert and riparian in hyper arid region is important for understanding eco-hydrological process. Field studies and numerical simulations were imported to evaluate the water and vapor movement processes under non isothermal and lower water content conditions. The soil profiles (12 layers) in Gobi desert and riparian sites of Ejina were installed with sensors to monitor soil moisture and temperature for 1 year. The meteorological conditions and water table were measured by micro weather stations and mini-Divers respectively in the two sites. Soil properties, including particles composition, moisture, bulk density, water retention curve, and saturated hydraulic conductivity of two site soil profiles, was measured. The observations showed that soil temperatures for the two sites displayed large diurnal and seasonal fluctuations. Temperature gradients with depth resulted in a downward in summer and upward in winter and became driving force for thermal vapor movement. Soil moistures in Gobi desert site were very low and varied slowly with time. While the soil moistures in riparian site were complicated due to root distribution but water potentials remained uniform with time. The hydrus-1D was employed to simulate evapotranspiration processes. The simulation results showed the significant difference of evaporation rate in the Gobi desert and riparian sites.

Reproductive tactics of male bearded goby (Sufflogobius bibarbatus) in anoxic and hypoxic waters

Science.gov (United States)

Seivåg, Maria Larsen; Salvanes, Anne Gro Vea; Utne-Palm, Anne Christine; Kjesbu, Olav Si'gurd

2016-03-01

The bearded goby (Sufflogobius bibarbatus), a key species in the northern Benguela Upwelling Ecosystem, tolerates extremely low levels of oxygen. Yet little is known about how its reproduction is affected by these harsh living conditions. The distribution patterns of alternative reproductive tactics of male bearded goby across the continental shelf off Namibia were investigated. Histology and stereology were for the first time used to validate macroscopic maturity development by estimating volume fraction of the different stages of spermatogenesis using "Delesse principle", an approach so far for teleosts barely used in studies on testes but applied in advanced oocyte estimation. The macroscopic scale appeared suitable for the purpose, and the prevalence of territorial and sneaker tactics could therefore be documented. The sneakers had relative large testes and small seminal vesicles (SV), with the opposite being the case for the territorials. A third, numerous category with intermediate sized testes and SV was also recognized with unclear underlying tactical rationale, although regression analyses indicated similar investment in testes weight in relation to somatic weight as for the territorials. Low oxygen levels were the most important factor limiting spawning activity in territorial males. Our data suggested the existence of a spawning site on the outer shelf of the central Namibian shelf where the bottom water is hypoxic (oxygen saturation of 6.2-6.7%) while the anoxic middle shelf area (oxygen saturation of 1.7-2.9%) appeared to show too low oxygen levels for spawning to take place. Hence, significant parts of this large shelf area appear unsuited for successful reproduction of the bearded goby, in particular for nest building by the territorials.

A tough egg to crack: recreational boats as vectors for invasive goby eggs and transdisciplinary management approaches.

Science.gov (United States)

Hirsch, Philipp E; Adrian-Kalchhauser, Irene; Flämig, Sylvie; N'Guyen, Anouk; Defila, Rico; Di Giulio, Antonietta; Burkhardt-Holm, Patricia

2016-02-01

Non-native invasive species are a major threat to biodiversity, especially in freshwater ecosystems. Freshwater ecosystems are naturally rather isolated from one another. Nonetheless, invasive species often spread rapidly across water sheds. This spread is to a large extent realized by human activities that provide vectors. For example, recreational boats can carry invasive species propagules as "aquatic hitch-hikers" within and across water sheds. We used invasive gobies in Switzerland as a case study to test the plausibility that recreational boats can serve as vectors for invasive fish and that fish eggs can serve as propagules. We found that the peak season of boat movements across Switzerland and the goby spawning season overlap temporally. It is thus plausible that goby eggs attached to boats, anchors, or gear may be transported across watersheds. In experimental trials, we found that goby eggs show resistance to physical removal (90 mN attachment strength of individual eggs) and stay attached if exposed to rapid water flow (2.8 m·s(-1)for 1 h). When exposing the eggs to air, we found that hatching success remained high (>95%) even after eggs had been out of water for up to 24 h. It is thus plausible that eggs survive pick up, within-water and overland transport by boats. We complemented the experimental plausibility tests with a survey on how decision makers from inside and outside academia rate the feasibility of managing recreational boats as vectors. We found consensus that an installation of a preventive boat vector management is considered an effective and urgent measure. This study advances our understanding of the potential of recreational boats to serve as vectors for invasive vertebrate species and demonstrates that preventive management of recreational boats is considered feasible by relevant decision makers inside and outside academia.

New BRDF Model for Desert and Gobi Using Equivalent Mirror Plane Method, Establishment and Validation

Science.gov (United States)

Li, Y.; Rong, Z.

2017-12-01

The surface Bidirectional Reflectance Distribution Function (BRDF) is a key parameter that affects the vicarious calibration accuracy of visible channel remote sensing instrument. In the past 30 years, many studies have been made and a variety of models have been established. Among them, the Ross-li model was highly approved and widely used. Unfortunately, the model doesn't suitable for desert and Gobi quite well because of the scattering kernel it contained, needs the factors such as plant height and plant spacing. A new BRDF model for surface without vegetation, which is mainly used in remote sensing vicarious calibration, is established. That was called Equivalent Mirror Plane (EMP) BRDF. It is used to characterize the bidirectional reflectance of the near Lambertian surface. The accuracy of the EMP BRDF model is validated by the directional reflectance data measured on the Dunhuang Gobi and compared to the Ross-li model. Results show that the regression accuracy of the new model is 0.828, which is similar to the Ross-li model (0.825). Because of the simple form (contains only four polynomials) and simple principle (derived by the Fresnel reflection principle, don't include any vegetation parameters), it is more suitable for near Lambertian surface, such as Gobi, desert, Lunar and reference panel. Results also showed that the new model could also maintain a high accuracy and stability in sparse observation, which is very important for the retrieval requirements of daily updating BRDF remote sensing products.

Geochemistry and fluid characteristics of the Dalli porphyry Cu-Au deposit, Central Iran

Science.gov (United States)

Zarasvandi, Alireza; Rezaei, Mohsen; Raith, Johann; Lentz, David; Azimzadeh, Amir-Mortaza; Pourkaseb, Hooshang

2015-11-01

The Miocene Dalli porphyry Cu-Au deposit in the central part of Urumieh-Dokhtar magmatic arc is the first reported Au-rich porphyry Cu deposit in the Zagros orogenic belt. The Cu-Au mineralization is mainly hosted in diorite and quartz diorite intrusions, presenting as numerous veinlets in the altered wall rocks, with potassic, phyllic, and propylitic alteration developed. Based on the mineral assemblages and crosscutting relations of veinlets, hydrothermal mineralization-alteration occurred in at least three stages, characterized by veinlets of (1) Qtz + Kfs + Mag ± Ccp, (2) Qtz + Py + Ccp ± Bn ± Cv ± Cc and, (3) Qtz + Chl + Bt. The ore-bearing intrusions exhibit typical geochemical characteristics of subduction zone magmas, including LREE fractionated pattern, strong enrichment in LILE (Cs, Rb, Ba, Pb, and U), and depletion of HFSE, with marked negative Ti and Nb anomalies. The adakite-like ore-hosting porphyry intrusions are characterized by a systematic gradual decreasing and increasing of Y and Eu/Eu∗ with increasing SiO2 content, respectively. Moreover, they exhibit a significant increasing trend of Sr/Y with decreasing of Y, which indicates progressive hornblende fractionation and suppression of plagioclase fractionation during the evolution toward high water content of parental magma. A relatively flat HREE pattern with low Dyn/Ybn and Nb/Ta values may represent that amphibole played a more important role than garnet in the generation of the adakitic melts in the thickened lower crust. Based on the phase assemblages confirmed by detailed laser Raman spectroscopy analyses and proportion of solid, liquid, and gaseous components, five types of fluid inclusions were recognized, which are categorized as; (1) liquid-rich two phase (liquidH2O + vaporH2O) (IIA), (2) vapor-rich two phase (vaporH2O/CO2 + liquidH2O) (IIB), (3) high saline simple fluids (IIIA; liquidH2O + vaporH2O + Hl), (4) high saline opaque mineral-bearing fluids (IIIB; liquidH2O + vaporH2O

Extirpation and recolonization in a metapopulation of an endangered fish, the tidewater goby

Science.gov (United States)

Lafferty, K.D.; Swift, C.C.; Ambrose, R.F.

1999-01-01

The tidewater goby (Eucyclogobius newberryi), an endangered species in the United States, occurs in a series of isolated coastal wetlands in California. Using historical presence-absence data and our own surveys, we estimated annual rates of extirpation and recolonization for several populations of the goby in southern California. As predicted, large wetlands had lower rates of extirpation than small wetlands. There was a negative but statistically nonsignificant correlation between recolonization rate and distance to the nearest northerly source population. Populations at small sites were sensitive to drought, presumably because droughts can eliminate suitable habitat at small wetlands. Populations in small wetlands have declined over time, even after accounting for variation in stream flow, supporting the species' endangered status. Our study emphasizes the need to understand metapopulation dynamics for conserving species where the unit of conservation is a local population. It is also emphasizes the importance of not treating metapopulations as identical units. Finally, our results provide a means for describing the decline of a species that is complex in time and space and provide insight into how to target protection measures among metapopulations.

Chaque goutte compte – entrevue de Gabin Koto N'Gobi, boursier ...

International Development Research Centre (IDRC) Digital Library (Canada)

11 mai 2012 ... C'est la pénurie d'eau dans la région semi-aride dans le nord de son pays natal, le Bénin, qui est sa véritable motivation. ... M. Koto N'Gobi admet : « Au début, je n'étais pas tellement intéressé, puis je me suis rendu compte qu'une recherche sur cette question cadrait parfaitement avec ma formation en ...

First record of Pontian monkey goby, Neogobius fluviatilis (Pallas, 1814), in the Dutch Rhine

NARCIS (Netherlands)

Van Kessel, N.; Dorenbosch, M.; Spikmans, F.

2009-01-01

The Pontian monkey goby, Neogobius fluviatilis, was recorded for the first time in the Netherlands in March 2009. Seven specimens were caught in the lower parts of the River Rhine, at close distance of the German border. Based on the species invasive history, N. fluviatilis could become invasive.

Size Dependent Male Reproductive Tactic in the Two-Spotted Goby (Gobiusculus flavescens).

Science.gov (United States)

Utne-Palm, A C; Eduard, K; Jensen, K H; Mayer, I; Jakobsen, P J

2015-01-01

Male investment in testes and sperm duct gland in the polygamous nest breeding two-spotted goby Gobiusculus flavescens (Fabricius) was investigated in relation to time in reproductive season and individual physical parameters. This small teleost fish is most likely the most abundant species found along the rocky shores of the North East Atlantic. The two-spotted goby has a single reproductive season, during which nest-caring males can raise several clutches of offspring. According to the literature the males are on average larger than the females. Here we report for the first time a population showing a reversal of this trend, with males on average being smaller than females, a difference likely caused by a large proportion of small males. Early in the breeding season these small males have typical sneaker characters, with relatively large testes and small seminal duct glands compared to the larger dominant territorial males. The presence of these two alternative male reproductive tactics is confirmed by histological studies, which shows the presence of sperm in the sperm duct glands (SDG) of smaller males, but not in the SDG of intermediate and larger males. To our knowledge, males with typical sneaker characters have not been reported in earlier studied populations of two-spotted goby. Interestingly we found that testes investment declined significantly over the course of the breeding season, and that this reduction was significantly more pronounced in small compared to the large males. Further, a significant increase in seminal duct gland (SDG) mass was observed for the smaller males over the breeding season. We propose that this indicates a possible shift in mating tactic by smaller males from a parasitic to a nest-holding tactic over the course of the breeding season. Thus, the observed size dependent plasticity in investment in SDG over time suggests that the reproductive tactic of G. flavescens is conditional, and possibly influenced by mate availability and

Size Dependent Male Reproductive Tactic in the Two-Spotted Goby (Gobiusculus flavescens.

Directory of Open Access Journals (Sweden)

A C Utne-Palm

Full Text Available Male investment in testes and sperm duct gland in the polygamous nest breeding two-spotted goby Gobiusculus flavescens (Fabricius was investigated in relation to time in reproductive season and individual physical parameters. This small teleost fish is most likely the most abundant species found along the rocky shores of the North East Atlantic. The two-spotted goby has a single reproductive season, during which nest-caring males can raise several clutches of offspring. According to the literature the males are on average larger than the females. Here we report for the first time a population showing a reversal of this trend, with males on average being smaller than females, a difference likely caused by a large proportion of small males. Early in the breeding season these small males have typical sneaker characters, with relatively large testes and small seminal duct glands compared to the larger dominant territorial males. The presence of these two alternative male reproductive tactics is confirmed by histological studies, which shows the presence of sperm in the sperm duct glands (SDG of smaller males, but not in the SDG of intermediate and larger males. To our knowledge, males with typical sneaker characters have not been reported in earlier studied populations of two-spotted goby. Interestingly we found that testes investment declined significantly over the course of the breeding season, and that this reduction was significantly more pronounced in small compared to the large males. Further, a significant increase in seminal duct gland (SDG mass was observed for the smaller males over the breeding season. We propose that this indicates a possible shift in mating tactic by smaller males from a parasitic to a nest-holding tactic over the course of the breeding season. Thus, the observed size dependent plasticity in investment in SDG over time suggests that the reproductive tactic of G. flavescens is conditional, and possibly influenced by mate

Evidence for ontogenetically and morphologically distinct alternative reproductive tactics in the invasive Round Goby Neogobius melanostomus.

Science.gov (United States)

Bleeker, Katinka; de Jong, Karen; van Kessel, Nils; Hinde, Camilla A; Nagelkerke, Leopold A J

2017-01-01

Alternative reproductive tactics are characterized by the occurrence of discrete alternative morphs that differ in behavioural, morphological and physiological traits within the same sex. Although much effort has been made to describe the behaviour, morphology and physiology of such alternative morphs, less effort has been invested investigating how much overlap there is in the characteristics of such morphs in natural populations. We studied random population samples of the invasive Round Goby Neogobius melanostomus from five different localities in the river Rhine system in the Netherlands. We found two morphologically and physiologically distinct male morphs which likely represent alternative reproductive tactics. Almost all mature males under 9.35 cm total length had a gonadosomatic index > 3%, suggestive of a sneaker tactic, while nearly all males above 9.35 cm has a gonadosomatic index of sneaker morphs would be ca. 7.5 times as high as the gonad mass of parental morphs of the same total length after extrapolation. Few (9%) intermediates were found, suggesting that the expression of alternative reproductive tactics is determined before the first breeding season. This contrasts with studies on other goby species, which show evidence of plastic tactics that can be affected by social circumstances. We conclude that it is possible to distinguish two alternative male morphs in the Dutch Round Goby population using morphological measurements alone. Although behavioural observations are needed to provide conclusive evidence, the difference in GSI between these morphs indicates that these morphs reflect alternative reproductive tactics.

First records of reproductive behaviour and early development of the bearded goby Sufflogobius bibarbatus.

Science.gov (United States)

Skrypzeck, H; Salvanes, A G V; Currie, B; Kotze, A

2014-04-01

Data on developmental characteristics from fertilization to 2 days post-hatching during captivity of the anoxia tolerant bearded goby Sufflogobius bibarbatus, one of the keystone prey species for many of the commercial fish populations, sea mammals and birds in south-west Africa, are presented. © 2014 The Fisheries Society of the British Isles.

Can round goby (Neogobius melanostomus) caught by rod and line be used for diet analysis?

Czech Academy of Sciences Publication Activity Database

Jurajda, Pavel; Všetičková, Lucie; Polačik, Matej; Vassilev, M.

2013-01-01

Roč. 39, č. 1 (2013), s. 182-185 ISSN 0380-1330 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Neogobius melanostomus * Gobies * Danube * Diet * Sampling methodology * Selectivity Subject RIV: EH - Ecology, Behaviour Impact factor: 1.771, year: 2013

Reproduction of two-spotted goby, Gobiusculus flavescens, in captivity

Directory of Open Access Journals (Sweden)

Vera Teles

2014-06-01

Full Text Available The two-spotted goby, Gobiusculus flavescens, is a common fish species along rocky shores in northern European waters. It is a small (40-60 mm, semipelagic marine fish, forming loose shoals in association with microalgae vegetation and mussel beds growing on the rock surface. It is a short-lived species, with a life span of 1-2 years. Both sexes display courtship behaviour and have sexual ornamentation during the breeding season. Male ornaments consist of large dorsal fins with iridescent blue lines, and iridescent blue spots along the sides of the body. Females develop a conspicuous, bright orange belly at sexual maturity. Due to these characteristics this species could have a great interest for ornamental aquariums. In previous work the maintenance of G. flavescens at high temperatures (until 23°C was successful. The aim of this study was to test the reproduction in captivity of G. flavescens. Six replicates were used (18L aquariums at the temperature of 18°C. In each replicate, two males and four females were introduced to an aquarium, where the males chose between two nests and courted the females. During the 112 days of the experiment the females spawned five times but only three spawns had success. The eggs take approximately 8 days to become mature. On the three spawns have hatched 300, 361 and 510 larvae at a time. The larvae were kept in a separate container and fed with alive rotifers and survived a maximum of 21 days. The reproduction of the two-spotted goby in captivity is possible at 18°C, but it is necessary to improve the conditions to rearing the larvae.

Face your fears: cleaning gobies inspect predators despite being stressed by them.

Directory of Open Access Journals (Sweden)

Marta C Soares

Full Text Available social stressors typically elicit two distinct behavioural responses in vertebrates: an active response (i.e., "fight or flight" or behavioural inhibition (i.e., freezing. Here, we report an interesting exception to this dichotomy in a Caribbean cleaner fish, which interacts with a wide variety of reef fish clients, including predatory species. Cleaning gobies appraise predatory clients as potential threat and become stressed in their presence, as evidenced by their higher cortisol levels when exposed to predatory rather than to non-predatory clients. Nevertheless, cleaning gobies neither flee nor freeze in response to dangerous clients but instead approach predators faster (both in captivity and in the wild, and interact longer with these clients than with non-predatory clients (in the wild. We hypothesise that cleaners interrupt the potentially harmful physiological consequences elicited by predatory clients by becoming increasingly proactive and by reducing the time elapsed between client approach and the start of the interaction process. The activation of a stress response may therefore also be responsible for the longer cleaning service provided by these cleaners to predatory clients in the wild. Future experimental studies may reveal similar patterns in other social vertebrate species when, for instance, individuals approach an opponent for reconciliation after a conflict.

Socially induced tactic change in 2 types of sand goby sneaker males

OpenAIRE

Takeshi Takegaki; Ola Svensson; Charlotta Kvarnemo

2012-01-01

Male alternative reproductive tactics, like satellite or sneaking tactics, typically parasitize reproductively on a larger resource-holding tactic. In the sand goby, Pomatoschistus minutus, 2 types of sneaker males are known. Sneaker males with melanization, a typical male breeding coloration, have small testes and large sperm-duct glands, and sneaker males without melanization have large testes and small sperm-duct glands. We tested their potential to change into the nest-holding tactic expe...

78 FR 8745 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Tidewater Goby

Science.gov (United States)

2013-02-06

... the Tidewater Goby (Service 2005a; Recovery Plan). The basis for our action. Under the Act, we must... units in California (73 FR 5920, January 31, 2008). The lawsuit challenged the Service's failure to... to our Recovery Plan (Service 2005a), which is available from the Ventura Fish and Wildlife Office...

Double origin of the racer goby (Babka gymnotrachelus in Poland revealed with mitochondrial marker. Possible implications for the species alien/native status

Directory of Open Access Journals (Sweden)

Michal Grabowski

2015-09-01

Full Text Available In mid-1990s racer goby, Babka gymnotrachelus, penetrated to the Vistula and Western Bug rivers in Poland through the canal connecting the Baltic and the Black Sea basins, namely the Vistula and Dnieper drainages. In early 2000s, the species was reported from Polish section of the Strwiąż River that is an affluent of the Dniester River that drains to the Black Sea basin. According to the Polish legislation, the racer goby has been enlisted in as an alien invasive species that may pose threat to local biota. Our analysis of the mtDNA cytochrome b diversity revealed that the Vistula/Western Bug and Strwiąż populations are different genetic units. First one originated from the Dnieper River, while the second derives from the Dniester River. According to the results of mismatch analysis, both are in the stage of demographic and spatial expansion. The haplotype frequencies in population from the Vistula/Western Bug differ significantly from those in the source population in Dnieper, suggesting founder effect, possibly due to human-mediated introduction of low number of individuals. On the other side, the population in Strwiąż does not differ in structure from the one in Dniester, providing a hint towards spontaneous range expansion. Interpretation of our results in light of historical data lead to the conclusion that presence of racer goby in Strwiąż was probably overlooked in previous, spatially limited, studies. Thus, in Strwiąż the species should not be treated as alien, contrary to its status in the Vistula drainage. This double origin of racer goby populations in Poland creates a peculiar situation for national legislation procedures as one population is alien and invasive, while the other one is not. In light of our findings, the population from Strwiąż should be recognised as a special case. Steps should be undertaken to raise public awareness to prevent translocation of the gobies between the rivers to prevent deterioration of the

Evidence for ontogenetically and morphologically distinct alternative reproductive tactics in the invasive Round Goby Neogobius melanostomus.

Directory of Open Access Journals (Sweden)

Katinka Bleeker

Full Text Available Alternative reproductive tactics are characterized by the occurrence of discrete alternative morphs that differ in behavioural, morphological and physiological traits within the same sex. Although much effort has been made to describe the behaviour, morphology and physiology of such alternative morphs, less effort has been invested investigating how much overlap there is in the characteristics of such morphs in natural populations. We studied random population samples of the invasive Round Goby Neogobius melanostomus from five different localities in the river Rhine system in the Netherlands. We found two morphologically and physiologically distinct male morphs which likely represent alternative reproductive tactics. Almost all mature males under 9.35 cm total length had a gonadosomatic index > 3%, suggestive of a sneaker tactic, while nearly all males above 9.35 cm has a gonadosomatic index of < 3%, suggestive of a parental tactic. Cheek size and eye diameter alone were sufficient to distinguish the two morphs. Gonads had a different relationship with size in the two morphs, indicating separate growth trajectories. The gonad mass of sneaker morphs would be ca. 7.5 times as high as the gonad mass of parental morphs of the same total length after extrapolation. Few (9% intermediates were found, suggesting that the expression of alternative reproductive tactics is determined before the first breeding season. This contrasts with studies on other goby species, which show evidence of plastic tactics that can be affected by social circumstances. We conclude that it is possible to distinguish two alternative male morphs in the Dutch Round Goby population using morphological measurements alone. Although behavioural observations are needed to provide conclusive evidence, the difference in GSI between these morphs indicates that these morphs reflect alternative reproductive tactics.

Flowing water affects fish fast-starts: escape performance of the Hawaiian stream goby, Sicyopterus stimpsoni.

Science.gov (United States)

Diamond, Kelly M; Schoenfuss, Heiko L; Walker, Jeffrey A; Blob, Richard W

2016-10-01

Experimental measurements of escape performance in fishes have typically been conducted in still water; however, many fishes inhabit environments with flow that could impact escape behavior. We examined the influences of flow and predator attack direction on the escape behavior of fish, using juveniles of the amphidromous Hawaiian goby Sicyopterus stimpsoni In nature, these fish must escape ambush predation while moving through streams with high-velocity flow. We measured the escape performance of juvenile gobies while exposing them to a range of water velocities encountered in natural streams and stimulating fish from three different directions. Frequency of response across treatments indicated strong effects of flow conditions and attack direction. Juvenile S. stimpsoni had uniformly high response rates for attacks from a caudal direction (opposite flow); however, response rates for attacks from a cranial direction (matching flow) decreased dramatically as flow speed increased. Mechanical stimuli produced by predators attacking in the same direction as flow might be masked by the flow environment, impairing the ability of prey to detect attacks. Thus, the likelihood of successful escape performance in fishes can depend critically on environmental context. © 2016. Published by The Company of Biologists Ltd.

The fine structure of the sperm of the round goby (Neogobius melanostomus)

Science.gov (United States)

Allen, Jeffrey D.; Walker, Glenn K.; Nichols, Susan J.; Sorenson, Dorothy

2004-01-01

The fine structural details of the spermatozoon of the round goby are presented for the first time in this study. Scanning and transmission electron microscopic examination of testis reveals an anacrosomal spermatozoon with a slightly elongate head and uniformly compacted chromatin. The midpiece contains a single, spherical mitochondrion. Two perpendicularly oriented centrioles lie in a deep, eccentric nuclear fossa with no regularly observed connection to the nucleus. The flagellum develops bilateral fins soon after emerging from the fossa; each extends approximately 1 A?m from the axoneme and persists nearly the length of the flagellum.

How cuckoldry can decrease the opportunity for sexual selection: Data and theory from a genetic parentage analysis of the sand goby, Pomatoschistus minutus

Science.gov (United States)

Jones, Adam G.; Walker, DeEtte; Kvarnemo, Charlotta; Lindström, Kai; Avise, John C.

2001-01-01

Alternative mating strategies are common in nature and are generally thought to increase the intensity of sexual selection. However, cuckoldry can theoretically decrease the opportunity for sexual selection, particularly in highly polygamous species. We address here the influence of sneaking (fertilization thievery) on the opportunity for sexual selection in the sand goby Pomatoschistus minutus, a marine fish species in which males build and defend nests. Our microsatellite-based analysis of the mating system in a natural sand goby population shows high rates of sneaking and multiple mating by males. Sneaker males had fertilized eggs in ≈50% of the assayed nests, and multiple sneakers sometimes fertilized eggs from a single female. Successful males had received eggs from 2 to 6 females per nest (mean = 3.4). We developed a simple mathematical model showing that sneaking in this polygynous sand goby population almost certainly decreases the opportunity for sexual selection, an outcome that contrasts with the usual effects of cuckoldry in socially monogamous animals. These results highlight a more complex and interesting relationship between cuckoldry rates and the intensity of sexual selection than previously assumed in much of the literature on animal mating systems. PMID:11481481

Biology of the Sanzo's goby, Lesueurigobius sanzoi (de Buen, 1918, off Cabo Raso, Portugal

Directory of Open Access Journals (Sweden)

Cristina Paulo Martins

2004-06-01

Full Text Available The presence of Sanzos's goby, Lesueurigobius sanzoi (de Buen, 1918, off Cabo Raso, Portugal, is recorded for the first time. The biology of this population was studied using 11 samples collected between April 2000 and September 2001 at depths of 70-100 m on muddy and sandy bottoms. The females reach a standard length of 110 mm and the males 103 mm. It attains an age of 24 months, which equals two breeding seasons. The otoliths form two translucent rings each year, which corresponds to the winter growth and the reproduction period. Sanzo's gobies can be classified as prematur and standard individuals, according to whether the first breeding occurs before or after the first winter respectively. Standard individuals, which have an extended first growth, reach a longer length than prematur individuals, whose first growth is much shorter. Although discrete, sexual dimorphism was noticeable even outside the spawning season. The breeding season occurs between May and September/October with more than one spawning. The minimum length for which the maturity stage occurs is 64 mm, at an age of 0+. The feeding activity is quite constant throughout the year, and the diet consists predominantly of small crustacea and molluscs, although polychaets also feature commonly in its diet.

Population and reproductive characteristics of a non-native western tubenose goby (Proterorhinus semilunaris) population unaffected by gobiid competitors

Czech Academy of Sciences Publication Activity Database

Valová, Zdenka; Konečná, Markéta; Janáč, Michal; Jurajda, Pavel

2015-01-01

Roč. 10, č. 1 (2015), s. 57-68 ISSN 1798-6540 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Gobiidae * invasive species * non-indigenous * tubenose goby * population dynamics Subject RIV: EH - Ecology, Behaviour Impact factor: 1.955, year: 2015

Standardization of plasma vitellogenin level for surveying environmental estrogen pollution using the Japanese common goby Acanthogobius flavimanus.

Science.gov (United States)

Song, Jing; Nagae, Masaki; Soyano, Kiyoshi

2018-07-01

Field surveys of the impact of environmental estrogen (EE) pollution in aquatic wildlife have been conducted using vitellogenin (VTG) as a biomarker to evaluate the influence of EE. However, a standard baseline of VTG level that can be used to evaluate EE pollution has not been fully determined. To the best of our knowledge, the present study is the first to determine the standard baseline VTG level for evaluating the biological effects of EE pollution using the Japanese common goby (Acanthogobius flavimanus) as the target model fish. Plasma VTG and estradiol-17β (E 2 ) levels associated with the reproductive cycle of wild goby inhabiting an unpolluted environment were measured. Mean plasma VTG and E 2 levels exhibited similar changes, increasing in the yolk vesicle stage and peaking in the tertiary yolk stage in females. However, plasma VTG and E 2 levels showed no significant changes in males, remaining at low levels throughout the reproductive cycle. The highest VTG levels in females and males were 1.6 mg ml -1 and 124.87 ng ml -1 , respectively. These results indicate that the baseline level (normal level) in males was approximately 130 ng ml -1 at most. We concluded that the threshold between normal and abnormal levels with a 10% risk rate was 150 ng ml -1 in the wild male goby. Plasma VTG levels in males captured from Nagasaki Harbor were higher than the threshold in each reproductive developmental stage, indicating the possibility of EE pollution at this site. The biological standard baseline for VTG established in this study is useful for assessing EE pollution in natural waters. Copyright © 2018 John Wiley & Sons, Ltd.

A New Species of the Bay Goby Genus Eucyclogobius, Endemic to Southern California: Evolution, Conservation, and Decline.

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Camm C Swift

Full Text Available A geographically isolated set of southern localities of the formerly monotypic goby genus Eucyclogobius is known to be reciprocally monophyletic and substantially divergent in mitochondrial sequence and nuclear microsatellite-based phylogenies relative to populations to the north along the California coast. To clarify taxonomic and conservation status, we conducted a suite of analyses on a comprehensive set of morphological counts and measures from across the range of Eucyclogobius and describe the southern populations as a new species, the Southern Tidewater Goby, Eucyclogobius kristinae, now separate from the Northern Tidewater Goby Eucyclogobius newberryi (Girard 1856. In addition to molecular distinction, adults of E. kristinae are diagnosed by: 1 loss of the anterior supratemporal lateral-line canals resulting in higher neuromast counts, 2 lower pectoral and branched caudal ray counts, and 3 sets of measurements identified via discriminant analysis. These differences suggest ecological distinction of the two species. Previous studies estimated lineage separation at 2-4 million years ago, and mitochondrial sequence divergence exceeds that of other recognized fish species. Fish from Santa Monica Artesian Springs (Los Angeles County northward belong to E. newberryi; those from Aliso Creek (Orange County southward constitute E. kristinae. The lagoonal habitat of Eucyclogobius has been diminished or degraded, leading to special conservation status at state and federal levels beginning in 1980. Habitat of the newly described species has been impacted by a range of anthropogenic activities, including the conversion of closing lagoons to open tidal systems in the name of restoration. In the last 30 years, E. kristinae has only been observed in nine intermittently occupied lagoonal systems in northern San Diego County; it currently persists in only three sites. Thus, the new species is in imminent danger of extinction and will require ongoing active

Structure of the protein core of the glypican Dally-like and localization of a region important for hedgehog signaling

Energy Technology Data Exchange (ETDEWEB)

Kim, Min-Sung; Saunders, Adam M.; Hamaoka, Brent Y.; Beachy, Philip A.; Leahy, Daniel J. (Stanford-MED); (JHU)

2011-09-20

Glypicans are heparan sulfate proteoglycans that modulate the signaling of multiple growth factors active during animal development, and loss of glypican function is associated with widespread developmental abnormalities. Glypicans consist of a conserved, approximately 45-kDa N-terminal protein core region followed by a stalk region that is tethered to the cell membrane by a glycosyl-phosphatidylinositol anchor. The stalk regions are predicted to be random coil but contain a variable number of attachment sites for heparan sulfate chains. Both the N-terminal protein core and the heparan sulfate attachments are important for glypican function. We report here the 2.4-{angstrom} crystal structure of the N-terminal protein core region of the Drosophila glypican Dally-like (Dlp). This structure reveals an elongated, {alpha}-helical fold for glypican core regions that does not appear homologous to any known structure. The Dlp core protein is required for normal responsiveness to Hedgehog (Hh) signals, and we identify a localized region on the Dlp surface important for mediating its function in Hh signaling. Purified Dlp protein core does not, however, interact appreciably with either Hh or an Hh:Ihog complex.

Contextual modulation of social and endocrine correlates of fitness: insights from the life history of a sex changing fish.

Science.gov (United States)

Pradhan, Devaleena S; Solomon-Lane, Tessa K; Grober, Matthew S

2015-01-01

Steroid hormones are critical regulators of reproductive life history, and the steroid sensitive traits (morphology, behavior, physiology) associated with particular life history stages can have substantial fitness consequences for an organism. Hormones, behavior and fitness are reciprocally associated and can be used in an integrative fashion to understand how the environment impacts organismal function. To address the fitness component, we highlight the importance of using reliable proxies of reproductive success when studying proximate regulation of reproductive phenotypes. To understand the mechanisms by which the endocrine system regulates phenotype, we discuss the use of particular endocrine proxies and the need for appropriate functional interpretation of each. Lastly, in any experimental paradigm, the responses of animals vary based on the subtle differences in environmental and social context and this must also be considered. We explore these different levels of analyses by focusing on the fascinating life history transitions exhibited by the bi-directionally hermaphroditic fish, Lythrypnus dalli. Sex changing fish are excellent models for providing a deeper understanding of the fitness consequences associated with behavioral and endocrine variation. We close by proposing that local regulation of steroids is one potential mechanism that allows for the expression of novel phenotypes that can be characteristic of specific life history stages. A comparative species approach will facilitate progress in understanding the diversity of mechanisms underlying the contextual regulation of phenotypes and their associated fitness correlates.

Population structure, condition, and reproduction characteristics of native monkey goby, Neogobius fluviatilis (Actinopterygii: Perciformes Gobiidae), in the Bulgarian Danube

Czech Academy of Sciences Publication Activity Database

Konečná, Markéta; Jurajda, Pavel

2012-01-01

Roč. 42, č. 4 (2012), s. 321-327 ISSN 0137-1592 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : monkey goby * invasion * Bulgaria * Danube, condition * GSI * ovary structure Subject RIV: EH - Ecology, Behaviour Impact factor: 0.606, year: 2012

An endocrine disrupting chemical changes courtship and parental care in the sand goby

International Nuclear Information System (INIS)

Saaristo, Minna; Craft, John A.; Lehtonen, Kari K.; Lindstroem, Kai

2010-01-01

Endocrine disrupting chemicals (EDCs) are a diverse group of compounds that can mimic, block or modulate the synthesis of natural hormones. They are known to cause impairment of reproduction of aquatic organisms at very low concentrations. The aim of this study was to examine how exposure from 10 to 31 days to 17α-ethinyl estradiol (EE2, 41 ng L -1 ) affects the courtship and parental care behaviour of male sand gobies (Pomatoschistus minutus). The sand goby exhibits a polygynous mating system, where males compete for females and provide paternal care. First, male courtship performance towards a stimulus female was recorded with video camera. Secondly, after the male had received eggs his parental care behaviour was video recorded. In addition to behavioural endpoints, we measured the expression of hepatic vitellogenin (Vtg) and zona radiata protein (Zrp) mRNA, as well as common somatic indices. Our study shows that exposure to EE2 affected male fanning behaviour during both courtship and parental care. Interestingly, small exposed males increased their courtship fanning to similar levels as larger control males. However, during parental care egg fanning was not related to male size, and all exposed males fanned more than control males. The EE2-exposure induced Vtg and Zrp mRNA expression in males and decreased hepatosomatic index (HSI), and increased gonadosomatic index (GSI). Females prefer males that fan more, which will favour the small EDC exposed males. This may lead to mating that favours males that are not strong enough to tend the eggs until they hatch, thus decreasing the reproductive success of individuals.

Anticipation of Artemia sp. supply in the larviculture of the barber goby Elacatinus figaro (Gobiidae: Teleostei influenced growth, metamorphosis and alkaline protease activity

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Maria Fernanda da Silva-Souza

2015-09-01

Full Text Available The barber goby Elacatinus figaro is considered endangered due to overexploitation by the ornamental industry. Farming marine ornamental fishes, especially the threatened ones, can be one of the measures to minimize the pressure on the natural stocks. Among the priority issues for their production is the determination of the most appropriate feeding management. The feeding protocol commonly used in the larviculture of barber goby, when the start of Artemia sp. offer occurred at the 18th DAH (days after hatching (treatment T18, was modified, by anticipating brine shrimp supply in 6 days (treatment T12. Alkaline proteases activity, growth and metamorphosis of larvae were evaluated in both protocols. Juveniles at T12 showed higher weight (0.04 ± 0.001 g and lower activity of total alkaline proteases (1.3 ± 0.2 mU mg-1 protein compared to T18 (0.02 ± 0.001 g; 2.8 ± 0.4 mU mg-1 protein, respectively. With anticipation of brine shrimp, the commencing and end of larval transformation was observed earlier (at 24 and 34 DAH, respectively in comparison to those with the supply of Artemia sp. at 18 DAH (27 and 41 DAH, respectively. Thus, the Artemia sp. anticipation was beneficial during the larviculture of the barber goby, considering that larvae reached metamorphosis earlier.

Body size correlates with fertilization success but not gonad size in grass goby territorial males.

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Jose Martin Pujolar

Full Text Available In fish species with alternative male mating tactics, sperm competition typically occurs when small males that are unsuccessful in direct contests steal fertilization opportunities from large dominant males. In the grass goby Zosterisessor ophiocephalus, large territorial males defend and court females from nest sites, while small sneaker males obtain matings by sneaking into nests. Parentage assignment of 688 eggs from 8 different nests sampled in the 2003-2004 breeding season revealed a high level of sperm competition. Fertilization success of territorial males was very high but in all nests sneakers also contributed to the progeny. In territorial males, fertilization success correlated positively with male body size. Gonadal investment was explored in a sample of 126 grass gobies collected during the period 1995-1996 in the same area (61 territorial males and 65 sneakers. Correlation between body weight and testis weight was positive and significant for sneaker males, while correlation was virtually equal to zero in territorial males. That body size in territorial males is correlated with fertilization success but not gonad size suggests that males allocate much more energy into growth and relatively little into sperm production once the needed size to become territorial is attained. The increased paternity of larger territorial males might be due to a more effective defense of the nest in comparison with smaller territorial males.

Body size correlates with fertilization success but not gonad size in grass goby territorial males.

Science.gov (United States)

Pujolar, Jose Martin; Locatello, Lisa; Zane, Lorenzo; Mazzoldi, Carlotta

2012-01-01

In fish species with alternative male mating tactics, sperm competition typically occurs when small males that are unsuccessful in direct contests steal fertilization opportunities from large dominant males. In the grass goby Zosterisessor ophiocephalus, large territorial males defend and court females from nest sites, while small sneaker males obtain matings by sneaking into nests. Parentage assignment of 688 eggs from 8 different nests sampled in the 2003-2004 breeding season revealed a high level of sperm competition. Fertilization success of territorial males was very high but in all nests sneakers also contributed to the progeny. In territorial males, fertilization success correlated positively with male body size. Gonadal investment was explored in a sample of 126 grass gobies collected during the period 1995-1996 in the same area (61 territorial males and 65 sneakers). Correlation between body weight and testis weight was positive and significant for sneaker males, while correlation was virtually equal to zero in territorial males. That body size in territorial males is correlated with fertilization success but not gonad size suggests that males allocate much more energy into growth and relatively little into sperm production once the needed size to become territorial is attained. The increased paternity of larger territorial males might be due to a more effective defense of the nest in comparison with smaller territorial males.

First record of the blackfin coral goby, Paragobiodon lacunicolus (Kendall and Goldsborough, 1911), from the Red Sea

KAUST Repository

Alpermann, Tilman J.

2013-09-13

Three specimens of the blackfin coral goby, Paragobiodon lacunicolus, were collected in 2010 and 2011 at different locations of the eastern Red Sea along the coast of Saudi Arabia. Reexamination of 14 museum specimens from Eritrea also confirmed the presence of the species for the western Red Sea. This represents the first published report of P. lacunicolus from the Red Sea. © 2013 Blackwell Verlag GmbH.

First record of the blackfin coral goby, Paragobiodon lacunicolus (Kendall and Goldsborough, 1911), from the Red Sea

KAUST Repository

Alpermann, Tilman J.; Mee, J. K L; Berumen, Michael L.

2013-01-01

Three specimens of the blackfin coral goby, Paragobiodon lacunicolus, were collected in 2010 and 2011 at different locations of the eastern Red Sea along the coast of Saudi Arabia. Reexamination of 14 museum specimens from Eritrea also confirmed the presence of the species for the western Red Sea. This represents the first published report of P. lacunicolus from the Red Sea. © 2013 Blackwell Verlag GmbH.

An endocrine disrupting chemical changes courtship and parental care in the sand goby

Energy Technology Data Exchange (ETDEWEB)

Saaristo, Minna, E-mail: Minna.Saaristo@helsinki.fi [Department of Bio- and Environmental Sciences, University of Helsinki, P.O. Box 65, FI-00014 Helsinki (Finland); Craft, John A. [Biological and Biomedical Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow G4 0BA, Scotland (United Kingdom); Lehtonen, Kari K. [Finnish Environment Institute, Marine Research Centre, P.O. Box 140, FI-00251 Helsinki (Finland); Lindstroem, Kai [Environmental and Marine Biology, Abo Akademi University, FI-20520 Turku (Finland)

2010-05-10

Endocrine disrupting chemicals (EDCs) are a diverse group of compounds that can mimic, block or modulate the synthesis of natural hormones. They are known to cause impairment of reproduction of aquatic organisms at very low concentrations. The aim of this study was to examine how exposure from 10 to 31 days to 17{alpha}-ethinyl estradiol (EE2, 41 ng L{sup -1}) affects the courtship and parental care behaviour of male sand gobies (Pomatoschistus minutus). The sand goby exhibits a polygynous mating system, where males compete for females and provide paternal care. First, male courtship performance towards a stimulus female was recorded with video camera. Secondly, after the male had received eggs his parental care behaviour was video recorded. In addition to behavioural endpoints, we measured the expression of hepatic vitellogenin (Vtg) and zona radiata protein (Zrp) mRNA, as well as common somatic indices. Our study shows that exposure to EE2 affected male fanning behaviour during both courtship and parental care. Interestingly, small exposed males increased their courtship fanning to similar levels as larger control males. However, during parental care egg fanning was not related to male size, and all exposed males fanned more than control males. The EE2-exposure induced Vtg and Zrp mRNA expression in males and decreased hepatosomatic index (HSI), and increased gonadosomatic index (GSI). Females prefer males that fan more, which will favour the small EDC exposed males. This may lead to mating that favours males that are not strong enough to tend the eggs until they hatch, thus decreasing the reproductive success of individuals.

Exploring the Utility of Partial Cytochrome c Oxidase Subunit 1 for DNA Barcoding of Gobies

Directory of Open Access Journals (Sweden)

Hyung-Bae Jeon

2012-10-01

Full Text Available Gobiids are hyperdiverse compared with other teleost groups, with about 2,000 species occurring in marine, freshwater, and blackish habitats, and they show a remarkable variety of morphologies and ecology. Testing the effectiveness of DNA barcodes on species that have emerged as a result of radiation remains a major challenge in evolutionary biology. Here, we used the cytochrome c oxidase subunit 1 (COI sequences from 144 species of gobies and related species to evaluate the performance of distance-based DNA barcoding and to conduct a phylogenetic analysis. The average intra-genus genetic distance was considerably higher than that obtained in previous studies. Additionally, the interspecific divergence at higher taxonomic levels was not significantly different from that at the intragenus level, suggesting that congeneric gobies possess substantial interspecific sequence divergence in their COI gene. However, levels of intragenus divergence varied greatly among genera, and we do not provide sufficient evidence for using COI for cryptic species delimitation. Significantly more nucleotide changes were observed at the third codon position than that at the first and the second codons, revealing that extensive variation in COI reflects synonymous changes and little protein level variation. Despite clear signatures in several genera, the COI sequences did resolve genealogical relationships in the phylogenetic analysis well. Our results support the validity of COI barcoding for gobiid species identification, but the utilization of more gene regions will assist to offer a more robust gobiid species phylogeny.

Response of benthic macroinvertebrate assemblages to round (Neogobius melanostomus, Pallas 1814) and tubenose (Proterorhinus semilunaris, Heckel 1837) goby predation pressure

Czech Academy of Sciences Publication Activity Database

Mikl, Libor; Adámek, Zdeněk; Všetičková, Lucie; Janáč, Michal; Roche, Kevin Francis; Šlapanský, Luděk; Jurajda, Pavel

2017-01-01

Roč. 785, č. 1 (2017), s. 219-232 ISSN 0018-8158 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Invasive species * Gobies * Macroinvertebrates * Impact * European rivers * Diet Subject RIV: EH - Ecology, Behaviour OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 2.056, year: 2016

Contextual modulation of social and endocrine correlates of fitness: insights from the life history of a sex changing fish

Directory of Open Access Journals (Sweden)

Devaleena S Pradhan

2015-02-01

Full Text Available Steroid hormones are critical regulators of reproductive life history, and the steroid sensitive traits (morphology, behavior, physiology associated with particular life history stages can have substantial fitness consequences for an organism. Hormones, behavior and fitness are reciprocally associated and can be used in an integrative fashion to understand how the environment impacts organismal function. To address the fitness component, we highlight the importance of using reliable proxies of reproductive success, when studying proximate regulation of reproductive phenotypes. To understand the mechanisms by which the endocrine system regulates phenotype, we discuss the use of particular endocrine proxies and the need for appropriate functional interpretation of each. Lastly, in any experimental paradigm, the responses of animals vary based on the subtle differences in environmental and social context and this must also be considered. We explore these different levels of analyses by focusing on the fascinating life history transitions exhibited by the bi-directionally hermaphroditic fish, Lythrypnus dalli. Sex changing fish are excellent models for providing a deeper understanding of the fitness consequences associated with the behavioral and endocrine variation. We close by proposing that local regulation of steroids is one potential mechanism that allows for the expression of novel phenotypes that can be characteristic of specific life history stages. A comparative species approach will facilitate progress in understanding the diversity of mechanisms underlying the contextual regulation of phenotypes and their associated fitness correlates.

Late Quaternary strike-slip along the Taohuala Shan-Ayouqi fault zone and its tectonic implications in the Hexi Corridor and the southern Gobi Alashan, China

Science.gov (United States)

Yu, Jing-xing; Zheng, Wen-jun; Zhang, Pei-zhen; Lei, Qi-yun; Wang, Xu-long; Wang, Wei-tao; Li, Xin-nan; Zhang, Ning

2017-11-01

The Hexi Corridor and the southern Gobi Alashan are composed of discontinuous a set of active faults with various strikes and slip motions that are located to the north of the northern Tibetan Plateau. Despite growing understanding of the geometry and kinematics of these active faults, the late Quaternary deformation pattern in the Hexi Corridor and the southern Gobi Alashan remains controversial. The active E-W trending Taohuala Shan-Ayouqi fault zone is located in the southern Gobi Alashan. Study of the geometry and nature of slip along this fault zone holds crucial value for better understanding the regional deformation pattern. Field investigations combined with high-resolution imagery show that the Taohuala Shan fault and the E-W trending faults within the Ayouqi fault zone (F2 and F5) are left-lateral strike-slip faults, whereas the NW or WNW-trending faults within the Ayouqi fault zone (F1 and F3) are reverse faults. We collected Optically Stimulated Luminescence (OSL) and cosmogenic exposure age dating samples from offset alluvial fan surfaces, and estimated a vertical slip rate of 0.1-0.3 mm/yr, and a strike-slip rate of 0.14-0.93 mm/yr for the Taohuala Shan fault. Strata revealed in a trench excavated across the major fault (F5) in the Ayouqi fault zone and OSL dating results indicate that the most recent earthquake occurred between ca. 11.05 ± 0.52 ka and ca. 4.06 ± 0.29 ka. The geometry and kinematics of the Taohuala Shan-Ayouqi fault zone enable us to build a deformation pattern for the entire Hexi Corridor and the southern Gobi Alashan, which suggest that this region experiences northeastward oblique extrusion of the northern Tibetan Plateau. These left-lateral strike-slip faults in the region are driven by oblique compression but not associated with the northeastward extension of the Altyn Tagh fault.

Przewalski’ s Horse ( Equus ferus przewalskii Re-intr oduction in the Great Gobi B Strictly Protected Area: from Species to Ecosystem Conservation

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P. Kaczensky

2007-05-01

Full Text Available The Przewalski’s horse ( Equus ferus przewalskii Po ljakov , 1881, or “T akhi” in Mongolian, became extinct in the wild by the mid 1960’ s. The last recorded sightings of Przewalski’s horses occurred in the Dzungarian Gobi desert in SW Mo ngolia, today’s Great Gobi B Strictly Protected Area (SP A. A re - introduction program was initiated in 1992 and the fi rs t group of captive-born Przewalski’s horses was airlifted to the SPA. Given the logistical challenges associated with such a venture, the initial project focus has been on transport logistics and the well-being of the re-introduced horses. Tod ay, conservation efforts are spread over the entire protected area. Present day ef forts include other mammals, vegetation and the local people. Due to its important symbolic value in Mongolian culture, the Przewalski’ s horse became an important fl agship species for the protected area’s conservation and management.

Local adaptation despite high gene flow in the waterfall-climbing Hawaiian goby, Sicyopterus stimpsoni.

Science.gov (United States)

Moody, K N; Hunter, S N; Childress, M J; Blob, R W; Schoenfuss, H L; Blum, M J; Ptacek, M B

2015-02-01

Environmental heterogeneity can promote the emergence of locally adapted phenotypes among subpopulations of a species, whereas gene flow can result in phenotypic and genotypic homogenization. For organisms like amphidromous fishes that change habitats during their life history, the balance between selection and migration can shift through ontogeny, making the likelihood of local adaptation difficult to predict. In Hawaiian waterfall-climbing gobies, it has been hypothesized that larval mixing during oceanic dispersal counters local adaptation to contrasting topographic features of streams, like slope gradient, that can select for predator avoidance or climbing ability in juvenile recruits. To test this hypothesis, we used morphological traits and neutral genetic markers to compare phenotypic and genotypic distributions in recruiting juveniles and adult subpopulations of the waterfall-climbing amphidromous goby, Sicyopterus stimpsoni, from the islands of Hawai'i and Kaua'i. We found that body shape is significantly different between adult subpopulations from streams with contrasting slopes and that trait divergence in recruiting juveniles tracked stream topography more so than morphological measures of adult subpopulation differentiation. Although no evidence of population genetic differentiation was observed among adult subpopulations, we observed low but significant levels of spatially and temporally variable genetic differentiation among juvenile cohorts, which correlated with morphological divergence. Such a pattern of genetic differentiation is consistent with chaotic genetic patchiness arising from variable sources of recruits to different streams. Thus, at least in S. stimpsoni, the combination of variation in settlement cohorts in space and time coupled with strong postsettlement selection on juveniles as they migrate upstream to adult habitats provides the opportunity for morphological adaptation to local stream environments despite high gene flow. © 2014

From sneaker to parental male: change of reproductive traits in the black goby, Gobius niger (Teleostei, Gobiidae).

Science.gov (United States)

Immler, Simone; Mazzoldi, Carlotta; Rasotto, Maria Berica

2004-02-01

This study focuses on the consequences of the switch of tactic from parasitic to parental male in the black goby, Gobius niger (Teleostei: Gobiidae), a species showing two alternative male mating tactics. Older and larger males defend nests, court, and perform parental care on eggs, while younger and smaller ones behave as parasites, sneaking into nests while spawning occurs. Males adopting different tactics are known to present differences in primary and secondary sex traits. The social context of sneaker males was manipulated to induce a tactic switch. Sneakers were kept under two different experimental treatments with or without a female, and under exclusion of male-male competition. Males changed tactics, courting females, spawning, and performing parental care. All males showed substantial changes in primary sexual traits, such as a reduction in gonadal development and an increase in the investment in accessory structures. The experimental groups differed in the functionality of gonads and accessory organs and in the development of the secondary sex traits. These results demonstrate that the moment of switching is not genetically fixed in the black goby. Sneaker males are able to quickly reallocate energy in primary and secondary sex traits, in accordance with the adopted tactic. Several aspects of this flexible reproductive pattern resemble the socially controlled sex change found in sequential hermaphrodites. Copyright 2004 Wiley-Liss, Inc.

Ejaculate of sneaker males is pheromonally inconspicuous in the black goby, Gobius niger (Teleostei, Gobiidae).

Science.gov (United States)

Locatello, L; Mazzoldi, C; Rasotto, M B

2002-11-01

The black goby, Gobius niger, shows alternative male mating tactics, i.e., parental and sneaker males. Males release a sexual pheromone that attracts females and stimulates aggressive displays in males. This pheromone is produced by the mesorchial gland, a structure well developed in parental males but markedly undeveloped in sneakers. We measured the behavioral response of parental males to the ejaculates of males performing different reproductive tactics. Parental males reacted to the ejaculate of other parental males, with stereotypic aggressive behaviors, but not to the ejaculate of sneakers; consequently sneaker male ejaculate appears to be pheromonally inconspicuous. Copyright 2002 Wiley-Liss, Inc.

Stable isotopes suggest differences in diet between historic and reintroduced Przewalskís horses in the Gobi desert

Science.gov (United States)

Burnik Šturm, Martina; Spasskaya, Natalia N.; Sablin, Mikhail V.; Voigt, Christian C.; Kaczensky, Petra

2016-04-01

In historic times, two wild equid species, the Przewalski᾽s horse (PH; Equus ferus przewalskii) and the Asiatic wild ass (khulan, KH; Equus hemionus), roamed the Eurasian steppes. By the end of the 1960s, PHs had been driven to extinction in the wild and the range of KHs became severely restricted to the least productive habitats. However, PHs survived in captivity and reintroductions since the 1990s have brought the species back to parts of its native range in Mongolia and northern China where they again overlap with KHs. Ecological research on PHs and KHs has increased in recent years, but very little information is available on the ecology of the original PHs prior to extinction in the wild. We applied stable isotope analysis (13C, 15N, and 2H) of segmentally cut tail hair of PHs and KHs, collected during expeditions in NW China and SW Mongolia in 1889-1899, to draw inferences about the species feeding ecology. We compared tail hair isotope patterns of historic individuals to those of their extant counterparts from the Mongolian Gobi. A previous study of isotopic tail hair signatures of extant PHs (N=6) and KHs (N=6) suggested species specific differences in diet, with PHs being year-round grazers, but KHs switching between being grazers in summer and mixed feeders in winter (Burnik Šturm et al., in prep.). The comparison of isotope patterns of extant with historic samples confirms diet seasonality in historic KHs (N=3), but detects the same seasonality in five out of six PHs, suggesting that historic PHs had a different isotopic dietary niche than extant PHs. While we are still unable to fully understand the underlying reasons for this change in PHs, our results clearly suggest that the isotopic dietary niche of PHs was wider in the past, suggesting a higher diet flexibility, and overlapped with that of KHs, suggesting a high competition potential over Gobi pastures between the two equid species in historic times. Reference: Burnik Šturm, M., Ganbaatar, O

Spatial variation in background groundwater geochemistry of the Gurinai Wetland, Gobi Desert, Inner Mongolia

Science.gov (United States)

Gu, Weizu; Peters, N.E.

1995-01-01

Age dating of groundwater from several hand-dug wells in the Gurinai Wetland of the Badajilin-Gobi Desert, north-central China, indicated a continuum from present to 7625??155 years B.P. Water age correlates with concentration for some constituents. In general, concentrations of Fe, Cr, Se and Sr increase with increasing age, whereas Ca, Br, Zn and Rb decrease. Compared to concentration ranges reported for freshwaters, several constituents were much more concentrated including Na, Cl, Mg, Br and Th, and many others extended the upper concentration limit including Sr, Mo, Rb, Cr, U, Se, Nb and Ce. For Th, the maximum observed concentration extends the previously summarized maximum by more than an order of magnitude.

Parasitic spawning in sand gobies: an experimental assessment of nest-opening size, sneaker male cues, paternity, and filial cannibalism

OpenAIRE

Ola Svensson; Charlotta Kvarnemo

2007-01-01

Sneaking is common in nest-building fish with paternal care, but the role of nest-opening size in protecting against entry by sneaker males has never been tested before. Using the sand goby (Pomatoschistus minutus), a fish with exclusive paternal care, experimental manipulations of nest openings provided no support for the hypothesis that nest openings serve as physical or visual defense or that sneaker males prefer to parasitize nests with wide openings. Female mating preference was also not...

Seasonal diet pattern of non-native tubenose goby (Proterorhinus semilunaris in a lowland reservoir (Mušov, Czech Republic

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Adámek Z.

2010-08-01

Full Text Available The tubenose goby (Proterorhinus semilunaris is a gobiid species currently extending its area of distribution in Central Europe. The objective of the study was to evaluate the annual pattern of its feeding habits in the newly colonised habitats of the Mušov reservoir on the Dyje River (the Danube basin, Czech Republic with respect to natural food resources. In the reservoir, tubenose goby has established a numerous population, densely colonising stony rip-rap banks. Its diet was exclusively of animal origin with significant dominance of and preference for two food items – chironomid (Chironomidae larvae and waterlouse (Asellus aquaticus, which contributed 40.2 and 27.6%, respectively, to the total food bulk ingested. The index of preponderance for the two items was also very high, amounting to 73.8 and 26.5, respectively. In the annual pattern, a remarkable preference for chironomid larvae was recorded in the summer period whilst waterlouse were consumed predominantly in winter months. The proportion of other food items was rather marginal – only corixids, copepods, ceratopogonids and cladocerans were of certain minor importance with proportions of 5.4, 4.3, 4.1 and 3.9%, respectively. Certain signs of cannibalism were also recorded, with 0.9 and 0.2% of the diet consisting of their own progeny and eggs, respectively.

Triassic to Cenozoic multi-stage intra-plate deformation focused near the Bogd Fault system, Gobi Altai, Mongolia

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Douwe J.J. van Hinsbergen

2015-09-01

Full Text Available The Gobi Altai region of southern Mongolia has been in the Eurasian plate interior since the mid-Mesozoic, yet has experienced episodic phases of deformation since that time. In this paper, we document field evidence to characterize and date the intra-plate tectonic history of the Gobi Altai region from the Triassic to the present. To this end, we provide detailed mapping of the structure and stratigraphy of the eastern flanks of Mt. Ih Bogd that contains the widest variety of rock-time units in the area. We carry out geochronological analysis of basaltic lavas and basement granite in the area. We demonstrate that a crystalline basement with a 502 ± 8 Ma granitoid (U/Pb underwent two phases of basin formation in the Mesozoic, which we date with new 40Ar/39Ar lava ages of 218.5 ± 1.5, 123.2 ± 0.7 and 124.8 ± 1.2 Ma, respectively. Both phases are linked to deposition of fluvio-lacustrine sediments and trap-like basaltic volcanics, with cumulative thicknesses of 1000–1500 m. Both basins were likely north-facing half-grabens that developed under ∼N–S extension, but were subsequently overthrusted by Paleozoic and older crystalline basement during a less well constrained, but likely mid-Cretaceous phase of N–S shortening and basin inversion. Our results are consistent with recent seismic imaging of rift basins ∼100 km to the NE of the study area where a similar history was reconstructed. The multiple phases of intra-plate deformation appear to have parallel structural trends, most likely due to reactivated Paleozoic basement structures created during the original terrane amalgamation of the Central Asian Orogenic Belt continental crust. This strong basement heterogeneity may predispose it to reactivation, and make it sensitive to changes in the overall stress field of the Eurasian plate driven by forces at its margins and base. Detailed study of Mongolia's multi-stage tectonic history may thus provide a key proxy for the long

How old are you—Evaluation of age reading methods for the invasive round goby (Neogobius melanostomus, Pallas 1814)

DEFF Research Database (Denmark)

Florin, Ann-Britt; Hüssy, Karin; Blass, M.

2018-01-01

for an increasing knowledge of their basic stock structures such as growth rates, longevity and mortality, which all rely on accurate estimates of age. Former studies on the round goby have used several different age reading techniques. In this study, we compared three standard otolith preparation methods...... agreement was lowest when reading the whole otoliths while the best performance was achieved with sectioned and stained preparation method. Depending on method used the growth estimates also differed. The results question comparability between previous studies and highlight the importance of harmonised...

Do male desert gobies compromise offspring care to attract additional mating opportunities?

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Nicholas Symons

Full Text Available Males often play a critical role in offspring care but the time and energy invested in looking after young can potentially limit their ability to seek out additional mating opportunities. Recent studies, however, suggest that a conflict between male parental effort and mating effort may not always be inevitable, especially if breeding occurs near the nest, or if parental behaviours are under sexual selection. Accordingly, we set out to experimentally investigate male care and courtship in the desert goby Chlamydogobius eremius, a nest-guarding fish with exclusive paternal care. Despite courtship occurring near the nest, we found that when egg-tending males were given the opportunity to attract additional females, they fanned their eggs less often, engaged in shorter fanning bouts, and spent more of their time outside their nests courting. Our findings highlight the importance of understanding the circumstances under which reproductive tradeoffs are expected to occur and how these, in turn, operate to influence male reproductive decisions.

A study of variation characteristics of Gobi broadband emissivity based on field observational experiments in northwestern China

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Zheng, Zhi-yuan; Wei, Zhi-gang; Wen, Zhi-ping; Dong, Wen-jie; Li, Zhen-chao; Wen, Xiao-hang; Zhu, Xian; Chen, Chen; Hu, Shan-shan

2018-02-01

Land surface emissivity is a significant variable in energy budgets, land cover assessments, and environment and climate studies. However, the assumption of an emissivity constant is being used in Gobi broadband emissivity (GbBE) parameterization scheme in numerical models because of limited knowledge surrounding the spatiotemporal variation characteristics of GbBE. To address this issue, we analyzed the variation characteristics of GbBE and possible impact factor-surface soil moisture based on long-term continuous and high temporal resolution field observational experiments over a typical Gobi underlying surface in arid and semiarid areas in northwestern China. The results indicate that GbBE has obvious daily and diurnal variation features, especially diurnal cycle characteristics. The multi-year average of the daily average of GbBE is in the range of 0.932 to 0.970 with an average of 0.951 ± 0.008, and the average diurnal GbBE is in the range of 0.880 to 0.940 with an average of 0.906 ± 0.018. GbBE varies with surface soil moisture content. We observed a slight decrease in GbBE with an increase in soil moisture, although this change was not very obvious because of the low soil moisture in this area. Nevertheless, we think that soil moisture must be one of the most significant impact factors on GbBE in arid and semiarid areas. Soil moisture must be taken into account into the parameterization schemes of bare soil broadband emissivity in land surface models. Additional field experiments and studies should be carried out in order to clarify this issue.

„A byls v Gobi?“ Glosa k vydané publikaci „Cestou na Východ“ (Praha: Torst 2008

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Jáchym Topol

2017-10-01

Full Text Available Jak jsme s Karlem Cudlínem tuhle knížku dělali? Dobré ani špatné fotky nepotřebují žádné komentáře, na tom jsme se shodli už dávno. Jenže mně to nedalo a musel jsem se ho ptát. Kdys tam byl? Jak velký byly ty ryby? Jak choděj oblíkaný Mongolové? Byls v Gobi? Proč jsi fotil zrovna tohle?

Constraining lithospheric removal and asthenospheric input to melts in Central Asia: A geochemical study of Triassic to Cretaceous magmatic rocks in the Gobi Altai (Mongolia)

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Sheldrick, Thomas C.; Barry, Tiffany L.; Van Hinsbergen, Douwe J. J.; Kempton, Pamela D.

2018-01-01

Throughout northeast China, eastern and southern Mongolia, and eastern Russia there is widespread Mesozoic intracontinental magmatism. Extensive studies on the Chinese magmatic rocks have suggested lithospheric mantle removal was a driver of the magmatism. The timing, distribution and potential diachroneity of such lithospheric mantle removal remains poorly constrained. Here, we examine successions of Mesozoic lavas and shallow intrusive volcanic plugs from the Gobi Altai in southern Mongolia that appear to be unrelated to regional, relatively small-scale deformation; at the time of magmatism, the area was 200 km from any active margin, or, after its Late Jurassic-Early Cretaceous closure, from the suture of the Mongol-Okhotsk Ocean. 40Ar/39Ar radiometric age data place magmatic events in the Gobi Altai between 220 to 99.2 Ma. This succession overlaps Chinese successions and therefore provides an opportunity to constrain whether Mesozoic lithosphere removal may provide an explanation for the magmatism here too, and if so, when. We show that Triassic to Lower Cretaceous lavas in the Gobi Altai (from Dulaan Bogd, Noyon Uul, Bulgantiin Uul, Jaran Bogd and Tsagaan Tsav) are all light rare-earth element (LREE) and large-ion lithophile element (LILE)-enriched, with negative Nb and Ta anomalies (Nb/La and Ta/La ≤ 1). Geochemical data suggest that these lavas formed by low degrees of partial melting of a metasomatised lithospheric mantle that may have been modified by melts derived from recycled rutile-bearing eclogite. A gradual reduction in the involvement of garnet in the source of these lavas points towards a shallowing of the depth of melting after 125 Ma. By contrast, geochemical and isotope data from the youngest magmatic rocks in the area - 107-99 Ma old volcanic plugs from Tsost Magmatic Field - have OIB-like trace element patterns and are interpreted to have formed by low degrees of partial melting of a garnet-bearing lherzolite mantle source. These rocks did

Determination of phase compositions in ceramics from Gobi desert using complementary diffraction techniques

International Nuclear Information System (INIS)

Gilles, R.; Hoelzel, M.; Siouris, I.M.; Katsavounis, S.; Visser, D.; Brunelli, M.

2013-01-01

The city Khara Khoto is located in the Gobi desert in Inner Mongolia. This city was deserted in the late 14th century and rediscovered in the beginning of the 20th century. In the present study, ceramic sherds typical for the Khara Khoto area have been analysed using neutrons, laboratory X-ray diffraction, synchrotron radiation X-ray diffraction as well as optical microscopy as complementary probes in extracting information on the mineral phase compositions as well as on the firing conditions during the pottery production. The data evaluation was performed with the standard diffraction analysis package GSAS and the new developed program AmPhOrAe. The dominating phase is mullite (∼60 %) compared to a variable mixture of SiO 2 quartz and cristobalite phases (∼35 %) and feldspar as a minority phase. Refiring experiments on one of the sherds allow estimating the firing temperatures of the ceramics within the region of 1,150 and 1,250 deg C. (author)

Bioaccumulation of sodium alkyl sulfate zinc chloride and their mixture in young goby proterorhinus marmoratus pall

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Topcuoglu, S.; Birol, E. (Cekmece Nuclear Research and Training Center, Istanbul (Turkey))

1982-12-01

The bioaccumulation of labelled surfactant, 35S-labelled sodium lauryl sulfate and 65Zn-labelled zinc chloride, was investigated both as a mixture and alone by themselves in young goby. The concentration factor of 7.15 was calculated for the surfactant in the whole-body fish and there was no effect of zinc chloride on this bioaccumulation process. Biological half-life of the surfactant was around 35 hours. The effects of surfactants on the zinc accumulation were also followed under the same conditions. The results indicated that the sodium lauryl sulfate had no effect on the accumulation of zinc, however, the other surfactant, linear alkylbenzene sulfonate, caused a significant increase in the zinc accumulation in comparison with the control group, during the uptake period.

Bioaccumulation of sodium alkyl sulfate zinc chloride and their mixture in young goby proterorhinus marmoratus pall

International Nuclear Information System (INIS)

Topcuoglu, S.; Birol, E.

1982-01-01

The bioaccumulation of labelled surfactant, 35S-labelled sodium lauryl sulfate and 65Zn-labelled zinc chloride, was investigated both as a mixture and alone by themselves in young goby. The concentration factor of 7.15 was calculated for the surfactant in the whole-body fish and there was no effect of zinc chloride on this bioaccumulation process. Biological half-life of the surfactant was around 35 hours. The effects of surfactants on the zinc accumulation were also followed under the same conditions. The results indicated that the sodium lauryl sulfate had no effect on the accumulation of zinc, however, the other surfactant, linear alkylbenzene sulfonate, caused a significant increase in the zinc accumulation in comparison with the control group, during the uptake period. (author)

Differentiation and adaptive radiation of amphibious gobies (Gobiidae: Oxudercinae) in semi-terrestrial habitats.

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Polgar, G; Sacchetti, A; Galli, P

2010-11-01

During several surveys made in the region of the lower Fly River and delta, Papua New Guinea, nine species of oxudercine gobies (Gobiidae: Oxudercinae) were recorded: Boleophthalmus caeruleomaculatus, Oxuderces wirzi, Periophthalmodon freycineti, Periophthalmus darwini, Periophthalmus novaeguineaensis, Periophthalmus takita, Periophthalmus weberi, Scartelaos histophorus and Zappa confluentus. An exploratory multivariate analysis of their habitat conditions discriminated five guilds, differentially distributed in habitats with different quantities of environmental water and three guilds corresponding to different levels of salinity. A partial correspondence between phylogenetic and ecological categories suggested the presence of parallel adaptive radiations within different genera. In particular, the species found in the most terrestrial habitats (P. weberi) was also found in the widest range of conditions, suggesting that colonization of extreme semi-terrestrial and freshwater habitats by this species was facilitated by eurytypy. It is proposed that these findings provide insight into convergent adaptations for the vertebrate eco-evolutionary transition from sea to land. © 2010 The Authors. Journal of Fish Biology © 2010 The Fisheries Society of the British Isles.

A new mesophotic goby, Palatogobius incendius (Teleostei: Gobiidae, and the first record of invasive lionfish preying on undescribed biodiversity.

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Luke Tornabene

Full Text Available A new species of deep-reef fish in the goby genus Palatogobius is described from recent submersible collections off Curaçao and Dominica. Video footage of schools of this species reveal predation by the invasive Indo-Pacific lionfish (Pterois spp., the first record of undescribed fauna potentially being eaten by lionfish outside of its native range. We present molecular phylogenetic data for all valid species of Palatogobius and related genera, as well as a taxonomic key to the species of Palatogobius and a generic key to Palatogobius and related genera in the western Atlantic. Lastly, we discuss ecological and behavioral aspects of some deep-reef fishes in light of potential threats from invasive lionfish.

A new mesophotic goby, Palatogobius incendius (Teleostei: Gobiidae), and the first record of invasive lionfish preying on undescribed biodiversity.

Science.gov (United States)

Tornabene, Luke; Baldwin, Carole C

2017-01-01

A new species of deep-reef fish in the goby genus Palatogobius is described from recent submersible collections off Curaçao and Dominica. Video footage of schools of this species reveal predation by the invasive Indo-Pacific lionfish (Pterois spp.), the first record of undescribed fauna potentially being eaten by lionfish outside of its native range. We present molecular phylogenetic data for all valid species of Palatogobius and related genera, as well as a taxonomic key to the species of Palatogobius and a generic key to Palatogobius and related genera in the western Atlantic. Lastly, we discuss ecological and behavioral aspects of some deep-reef fishes in light of potential threats from invasive lionfish.

Genetic architecture of the marbled goby Pomatoschistus marmoratus (Perciformes, Gobiidae) in the Mediterranean Sea.

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Mejri, Randa; Arculeo, Marco; Hassine, Oum Kalthoum Ben; Brutto, Sabrina Lo

2011-02-01

The marbled goby Pomatoschistus marmoratus, a species inhabiting coastal Mediterranean lagoons, has been studied by measuring its mitochondrial DNA variation. This analysis revealed a Mediterranean west vs east split and, subsequently, an eastern differentiation among the Libyan-Tunisian Gulf, the Adriatic Sea and the Aegean Sea. The high cohesion between the samples collected in the vast area of western Mediterranean contrasts with the genetic mosaic of the more sub-structured eastern Mediterranean. This western homogeneity can not yet be fully explained even if a human-mediated migratory flow, due to a maritime traffic, has been posited. The pattern in the eastern basin revealed a genetic architecture possibly due to the non-migratory habit of the gobid. Within this perspective, the role of the Mediterranean lagoon habitat should be related to how much it amplifies the effects of historical (e.g. past sea-level changes) and environmental (e.g. present-day hydrographic regime) processes as regards the genetic structure of the inhabiting species. Copyright © 2010 Elsevier Inc. All rights reserved.

Fungal Ferromanganese Mineralisation in Cretaceous Dinosaur Bones from the Gobi Desert, Mongolia.

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Owocki, Krzysztof; Kremer, Barbara; Wrzosek, Beata; Królikowska, Agata; Kaźmierczak, Józef

2016-01-01

Well-preserved mycelia of fungal- or saprolegnia-like biota mineralised by ferromanganese oxides were found for the first time in long bones of Late Cretaceous dinosaurs from the Gobi Desert (Nemegt Valley, Mongolia). The mycelia formed a biofilm on the wall of the bone marrow cavity and penetrated the osteon channels of the nearby bone tissue. Optical microscopy, Raman, SEM/EDS, SEM/BSE, electron microprobe and cathodoluminescence analyses revealed that the mineralisation of the mycelia proceeded in two stages. The first stage was early post-mortem mineralisation of the hyphae by Fe/Mn-oxide coatings and microconcretions. Probably this proceeded in a mildly acidic to circumneutral environment, predominantly due to heterotrophic bacteria degrading the mycelial necromass and liberating Fe and Mn sorbed by the mycelia during its lifetime. The second stage of mineralisation, which proceeded much later following the final burial of the bones in an alkaline environment, resulted from the massive precipitation of calcite and occasionally barite on the iron/manganese-oxide-coated mycelia. The mineral phases produced by fungal biofilms colonising the interiors of decaying dinosaur bones not only enhance the preservation (fossilisation) of fungal remains but can also be used as indicators of the geochemistry of the dinosaur burial sites.

Specific characteristics of essential oils of four Artemisia species from the Mongolian Trans-Altai Gobi

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N. Javzmaa

2016-03-01

Full Text Available The essential oil compositions of four Artemisia species in Mongolian Trans-Altai Gobi were studied by gas chromatography (GC and gas chromatography-mass spectrometry (GC-MS. The oil from A.macrocephala Jacq and A.dracunculus Ledeb. were characterized by the presence of monoterpene hydrocarbons and oxygenated monoterpeneoids predominately. E-nerolidol (26.95%, methyleugenol (23.29% and sabinene (13.21% were found as main components in the essential oils of A.dracunculus. A.macrocephalla was characterized by the presence of chamazulene (13.8%, cineol (11.7%, myrcene (9.0%, germacrene-D (7.1%. A.anethifolia Web was characterized by the presence of fragrant compounds as camphor (26.05%, α-thujone (10.1%, borneol (5.1%. Davanone and davanone derivatives were also detected in the sample in amount of 7.7% in total. A.scoparia Waldst differed by domination of monoterpene hydrocarbons (78.9% with (Z- β-ocimene (29.24%, α-pinene (15.19%, limonene (10.27% and myrcene (9.61%.Mongolian Journal of Chemistry 16 (42, 2015, 34-38

Bacterial diversity of surface sand samples from the Gobi and Taklamaken deserts.

Science.gov (United States)

An, Shu; Couteau, Cécile; Luo, Fan; Neveu, Julie; DuBow, Michael S

2013-11-01

Arid regions represent nearly 30 % of the Earth's terrestrial surface, but their microbial biodiversity is not yet well characterized. The surface sands of deserts, a subset of arid regions, are generally subjected to large temperature fluctuations plus high UV light exposure and are low in organic matter. We examined surface sand samples from the Taklamaken (China, three samples) and Gobi (Mongolia, two samples) deserts, using pyrosequencing of PCR-amplified 16S V1/V2 rDNA sequences from total extracted DNA in order to gain an assessment of the bacterial population diversity. In total, 4,088 OTUs (using ≥97 % sequence similarity levels), with Chao1 estimates varying from 1,172 to 2,425 OTUs per sample, were discernable. These could be grouped into 102 families belonging to 15 phyla, with OTUs belonging to the Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria phyla being the most abundant. The bacterial population composition was statistically different among the samples, though members from 30 genera were found to be common among the five samples. An increase in phylotype numbers with increasing C/N ratio was noted, suggesting a possible role in the bacterial richness of these desert sand environments. Our results imply an unexpectedly large bacterial diversity residing in the harsh environment of these two Asian deserts, worthy of further investigation.

Painted Goby Larvae under High-CO2 Fail to Recognize Reef Sounds.

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Joana M Castro

Full Text Available Atmospheric CO2 levels have been increasing at an unprecedented rate due to anthropogenic activity. Consequently, ocean pCO2 is increasing and pH decreasing, affecting marine life, including fish. For many coastal marine fishes, selection of the adult habitat occurs at the end of the pelagic larval phase. Fish larvae use a range of sensory cues, including sound, for locating settlement habitat. This study tested the effect of elevated CO2 on the ability of settlement-stage temperate fish to use auditory cues from adult coastal reef habitats. Wild late larval stages of painted goby (Pomatoschistus pictus were exposed to control pCO2 (532 μatm, pH 8.06 and high pCO2 (1503 μatm, pH 7.66 conditions, likely to occur in nearshore regions subjected to upwelling events by the end of the century, and tested in an auditory choice chamber for their preference or avoidance to nighttime reef recordings. Fish reared in control pCO2 conditions discriminated reef soundscapes and were attracted by reef recordings. This behaviour changed in fish reared in the high CO2 conditions, with settlement-stage larvae strongly avoiding reef recordings. This study provides evidence that ocean acidification might affect the auditory responses of larval stages of temperate reef fish species, with potentially significant impacts on their survival.

Early Engagement of Stakeholders with Individual-Based Modeling Can Inform Research for Improving Invasive Species Management: The Round Goby as a Case Study

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Emma Samson

2017-11-01

Full Text Available Individual-based models (IBMs incorporating realistic representations of key range-front processes such as dispersal can be used as tools to investigate the dynamics of invasive species. Managers can apply insights from these models to take effective action to prevent further spread and prioritize measures preventing establishment of invasive species. We highlight here how early-stage IBMs (constructed under constraints of time and data availability can also play an important role in defining key research priorities for providing key information on the biology of an invasive species in order that subsequent models can provide robust insight into potential management interventions. The round goby, Neogobius melanostomus, is currently spreading through the Baltic Sea, with major negative effects being reported in the wake of its invasion. Together with stakeholders, we parameterize an IBM to investigate the goby's potential spread pattern throughout the Gulf of Gdansk and the Baltic Sea. Model parameters were assigned by integrating information obtained through stakeholder interaction, from scientific literature, or estimated using an inverse modeling approach when not available. IBMs can provide valuable direction to research on invasive species even when there is limited data and/or time available to parameterize/fit them to the degree to which we might aspire in an ideal world. Co-development of models with stakeholders can be used to recognize important invasion patterns, in addition to identifying and estimating unknown environmental parameters, thereby guiding the direction of future research. Well-parameterized and validated models are not required in the earlier stages of the modeling cycle where their main utility is as a tool for thought.

Prey preference of snow leopard (Panthera uncia in South Gobi, Mongolia.

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Wasim Shehzad

Full Text Available Accurate information about the diet of large carnivores that are elusive and inhabit inaccessible terrain, is required to properly design conservation strategies. Predation on livestock and retaliatory killing of predators have become serious issues throughout the range of the snow leopard. Several feeding ecology studies of snow leopards have been conducted using classical approaches. These techniques have inherent limitations in their ability to properly identify both snow leopard feces and prey taxa. To examine the frequency of livestock prey and nearly-threatened argali in the diet of the snow leopard, we employed the recently developed DNA-based diet approach to study a snow leopard population located in the Tost Mountains, South Gobi, Mongolia. After DNA was extracted from the feces, a region of ∼100 bp long from mitochondrial 12S rRNA gene was amplified, making use of universal primers for vertebrates and a blocking oligonucleotide specific to snow leopard DNA. The amplicons were then sequenced using a next-generation sequencing platform. We observed a total of five different prey items from 81 fecal samples. Siberian ibex predominated the diet (in 70.4% of the feces, followed by domestic goat (17.3% and argali sheep (8.6%. The major part of the diet was comprised of large ungulates (in 98.8% of the feces including wild ungulates (79% and domestic livestock (19.7%. The findings of the present study will help to understand the feeding ecology of the snow leopard, as well as to address the conservation and management issues pertaining to this wild cat.

COMPARATIVE CHARACTERISTICS OF MORPHOMETRIC PARAMETERS OF MONKEY GOBY (NEOGOBIUS FLUVIATILIS PALLAS OF FRESH AND SALINE WATER RESERVOIRS IN UKRAINE

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V. P. Onoprienko

2014-04-01

physiological processes. The result of this effect is the difference in weight, size and body parts. To clarify, as our model species was taken Cottus Sandpiper (Neogobius fluviatilis Pallas. The reason for this was the fact that this species, along with other Ponto- Caspian solonovato - freshwater gobies, the International Union for Conservation of Nature classified as species biology are poorly understood and require further research. This fact that deepened interest of ichthyologists in this group of fish, in this regard appeared in the literature as material for the bulls and in Sandpiper. Based on the above, the purpose of this paper is a comparative morphometric parameters characteristic of individuals of this species of fresh and salt water bodies of Ukraine. All this affects the absolute morphometric parameters, which decrease in the direction from sea to the river. However, it should be noted that in rivers with rich feeding grounds sheer size of some individuals close to the size and species of sea Kakhovskoe reservoir. This situation is observed in the Sandpiper Grouse River. Here are some specimens reach a length (TL 118-148 mm and a weight of 15-36 g, Kakhovskoe Reservoir: 106-150 mm 11-38 g, in the Sea of ​​Azov: 115-174 mm 17-58 g. For relative parameters Sandpiper with these reservoirs are more similar, however, for some of them, there are differences. Among the latter is most clearly distinguished the ratio SL / N. This indicator podovzhenist (prohonystist body. As pointed out by VP Mitrofanov (1977, this indicator shows the hydrodynamic qualities of fish: the larger the index, the more active lifestyle is individual. When compared with individuals with a little water and a large stream, in the latter case, individuals are more elongated. This is confirmed by our material: the ratio SL / L for the smallest species of sea of ​​Azov (4.96, slightly more for Kakhovsky reservoir (5.52 and even more for rivers Grouse, Trubizh, Desna, Ros (respectively 5, 86

Malfunction Rates of Bird Flight Diverters on Powerlines in the Mongolian Gobi

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Batsuuri Dashnyam

2016-11-01

Full Text Available The Oyu Tolgoi (OT project, one of the world’s largest copper and gold mines, is located in Gobi Desert of Mongolia. To help meet its target of Net Positive Impact on key biodiversity features such as the Houbara bustard (Chlamydotis undulata the OT installed bird fl ight diverters (BFDs include spiral and fl apper devices to its power transmission lines to reduce the risk of birds hitting the wires. Despite the many studies demonstrating that BFDs reduce collision rates, we could fi nd no published information on malfunction rates of BFDs. In January 2013, we surveyed the physical function of 1,200 BFDs (e.g. 600 fl appers and 600 spirals in three sample areas on each of four lines of varying voltage and structure. Of the 600 fl appers examined, 123 had malfunctioned within nine months of installation, while the malfunction rate of the 600 spirals studied was zero. Using a Generalized Linear Mixed Model, we found that the rate of fl apper malfunction increased with decreasing fl apper size and power line diameter. Further, the fl apper malfunction rate increased as the distance between poles increased. The cost of replacing malfunctioning BFDs is very high as there are serious health and safety constraints related to working with live wires. Factors aff ecting diverter malfunctioning need to be considered for future powerline projects and our information can serve as basis for developing national standards or regulations for powerline mitigation in Mongolia.

Reproductive parameters of invasive population of Round goby (Neogobius melanostomus Pallas, 1814) in the Slovak part of the Danube river - preliminary results; Reprodukcne parametre invaznej populacie bycka ciernousteho (Neogobius melanostomus Pallas, 1814) v slovenskom useku Dunaja - predbezne vysledky

Energy Technology Data Exchange (ETDEWEB)

Horkova, K [Univerzita Komenskeho v Bratislave, Prirodovedecka fakulta, Katedra ekologie, 84215 Bratislava (Slovakia)

2012-04-25

Round goby has a high invasive potential and huge expansive scattering. A suitable reproduction strategy probably helps him in successful colonizing of new territories. This allows him to create offspring also in the environments with constantly changing conditions. The aim of this work was to: (1) Analyze vital signs flexibility of bull populations living in different habitats (Karloveske rameno - less stable habitat, Cunovo - stable habitat). (2) Determine whether the disturbance, which occurred in 2010 on a site Karloveske rameno expressed in reproductive parameters of this population. To achieve the objectives it was necessary to analyze reproductive parameters of the bull individuals from both locations. The population of goby from Karloveske rameno has statistically significantly greater total mean of oocytes and oocyte diameter in different size groups and a higher average value of gonadosomatic index compared with a population of Cunovo. The absolute fertility and relative fertility was lower in Karloveske rameno population despite the fact that a given population had a greater range of values of absolute fertility. (author)

Point irrigation for locality Buchel in the north desert Gobi in Mongolia

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Pavel Spitz

2009-01-01

Full Text Available The design of point irrigation, created by Filip et al. (2007, was worked up as the bilateral projekt in the frame of abroad developing cooperation between the Czech Republic and Mongolia „Rehabilitation of plant production in semiarid territories of northern Gobi”. The period of project realization are years 2006–2009. The responsible institution for the project is Ministery of Agriculture of the Czech Republic and with the realization of the project was encharged Mendel University of Agriculture and Forestry in Brno. The task was work irrigation design for experimental plants and vegetables on the choosen land in Gobi desert in Mongolia. To disposition was underground water source – bore with capacity about 2 l / s and temperature about 10 °C, electric power and land about area cca 1 ha. The condition was use simple irrigation equipment. The fundamental limitation was im­pos­si­bi­li­ty using technically more complex and more sophisticated equipment e.g. drip irrigation. The map was not to the disposition, only a judgment of slope 0,2 % in flat terrain. The technical design of surface and subsurface point irrigation are introduced, shortly described are hydrotechnical basis used to created and described the original PC program HYBOZAM (hydraulics of point irrigation for Mongolia developed in table editor of Microsoft Excel for pipe dimensions of point irrigation design. Part of the program is also evaluation of the irrigation uniformity from outflows on irrigation line.

First report on intersex in invasive round goby Neogobius melanostomus from the Baltic Sea (Gulf of Gdańsk, Poland

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Tatiana Guellard

2015-01-01

Full Text Available This study is the first to report the presence of intersex in invasive round goby Neogobius melanostomus inhabiting the Baltic Sea. The discovery was made in the area of two harbours of the Gulf of Gdańsk (Poland. Macro- and microscopic male gonad analysis revealed the presence of female gametes in testes (testis-ova of single specimens. In addition, a female-like urogenital papilla was observed in one of the intersex fish. These findings might be due to the exposure to estrogenic endocrine disrupting compounds (EDCs however the occurrence of single intersex individuals as a baseline level in investigated population is also possible. In the future, more comprehensive research in the other areas of the Gulf of Gdańsk needs to be carried out in order to determine the extent and to better understand the cause of the observed phenomenon.

First record of Pontian Monkey Goby, Neogobius fluviatilis (Pallas, 1814 in the Evros River (Greece; Is it an alien species?

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S. ZOGARIS

2011-11-01

Full Text Available The Pontian Monkey Goby,Neogobius fluviatilis (Pallas, 1814, was recorded for the first time in Greece in August 2011. Eight specimens were collected in the Greek-Turkish section of the Evros River, 65 kilometers upstream of its river-mouth. Although the species has been recently discovered in the Tundza, a tributary of the Evros in Bulgaria, it has never before been found in the Evros’ main stem.  Although the lower Evros has been poorly researched by ichthyologists, it is unlikely that a conspicuous medium-sized fish would go unnoticed in this river; and, it is therefore suggested to be a probable alien. However, since the Evros basin has had geological connections to the Marmara Sea and Black Sea in the past and it is immediately adjacent to native populations of N. fluviatilis, the species status is categorized as questionable until genetic and morphological studies are completed.

Life cycle of the pelagic goby Aphia minuta (Pisces: Gobiidae

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M. Iglesias

2001-09-01

Full Text Available Reproductive aspects of the transparent goby Aphia minuta (n=2977, 14-45 mm total length (TL were studied in Majorcan waters, western Mediterranean, during the fishing season (December to April from 1985 to 1993. Male:female sex ratio was 1:1. Size at first maturity was 38 mm TL for females and 34 mm TL for males. Oocyte size-frequency distribution indicated that A. minuta is a single spawner. Fecundity of A. minuta ranged from 935 to 2648 oocytes. The breeding season extended from December to April with a peak in March. After a single reproduction at 5-6 months of age, most of the specimens disappeared from the fishing areas. Recruitment to the fishing area occurred in late December and early January (14-24 mm TL, age 2-3 months. On the other hand, the hatch date back-calculated from the age in days and the date of capture of individuals of A. minuta during the fishing season, indicated a spawning peak in autumn (September-October, six months after the peak of observed spawning. Schools of A. minuta were detected by acoustic methods, during the fishing season (winter-spring in fishing areas (5-40 m depth, principally inside bays, and during the rest of the year (summer and autumn in deeper areas (40-90 m, outside bays, with water temperatures between 13 and 16ºC and a high seasonal productivity in each depth range. Therefore, we propose that A. minuta has two annual cohorts in the western Mediterranean, corresponding to two main spawning in spring and autumn, respectively. Life history pattern indicated that we only know the winter cohort resulting from the autumn spawning. Meanwhile the summer cohort (spring spawning grows and reproduces in deeper areas not being targeted by the fishery. Indirect validation is provided from information from other areas. The relevance of the life cycle is discussed in relation to fishery management.

Drosophila Glypicans Regulate Follicle Stem Cell Maintenance and Niche Competition.

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Su, Tsu-Yi; Nakato, Eriko; Choi, Pui Yee; Nakato, Hiroshi

2018-04-09

Adult stem cells reside in specialized microenvironments, called niches, which provide signals for stem cells to maintain their undifferentiated and self-renewing state. To maintain stem cell quality, several types of stem cells are known to be regularly replaced by progenitor cells through niche competition. However, the cellular and molecular bases for stem cell competition for niche occupancy are largely unknown. Here, we show that two Drosophila members of the glypican family of heparan sulfate proteoglycans (HSPGs), Dally and Dally-like (Dlp), differentially regulate follicle stem cell (FSC) maintenance and FSC competitiveness for niche occupancy. Lineage analyses of glypican mutant FSC clones showed that dally is essential for normal FSC maintenance. In contrast, dlp is a hyper-competitive mutation: dlp mutant FSC progenitors often eventually occupy the entire epithelial sheet. RNAi knockdown experiments showed that Dally and Dlp play both partially redundant and distinct roles in regulating Jak/Stat, Wg and Hh signaling in FSCs. The Drosophila FSC system offers a powerful genetic model to study the mechanisms by which HSPGs exert specific functions in stem cell replacement and competition. Copyright © 2018, Genetics.

Effects of sewage effluent and ethynyl oestradiol upon molecular markers of oestrogenic exposure, maturation and reproductive success in the sand goby (Pomatoschistus minutus, Pallas)

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Robinson, Craig D.; Brown, Elaine; Craft, John A.; Davies, Ian M.; Moffat, Colin F.; Pirie, David; Robertson, Fiona; Stagg, Ronald M.; Struthers, Susan

2003-01-01

Male fish in several UK estuaries are known to be exposed to oestrogenic contamination, and whilst a limited number of studies have shown that exposure to oestrogens can reduce the reproductive success of fish, the impact of environmentally relevant exposures is less clear. The aim of this study was, therefore, to investigate the effects of exposure to environmentally realistic concentrations of a sewage effluent and the synthetic oestrogen 17α-ethynyl oestradiol (EE 2 ) upon the reproductive success of a marine fish. Sand goby (Pomatoschistus minutus) were exposed for 7 months to EE 2 or a sewage effluent containing known xeno-oestrogens (alkylphenol polyethoxylates) and bred using within treatment crosses. Nominal exposure concentrations were 6 ng l -1 EE 2 , 0.3 or 0.03% v/v sewage effluent. At the end of the breeding trials, expression of hepatic zona radiata protein (Zrp) and vitellogenin (Vtg) mRNA were determined using two recently developed cDNA probes. Exposure to 6 ng l -1 EE 2 induced Zrp and Vtg mRNA expression in male and female sand goby, impaired male maturation and reproductive behaviour, reduced female fecundity and reduced egg fertility. As a consequence, fertile egg production of the EE 2 -exposed population was reduced by 90%. Exposure to sewage effluent (0.3% v/v) increased adult mortality and female Zrp and Vtg mRNA expression, but did not induce male vitellogenesis. Exposure to EE 2 and 0.3% v/v sewage effluent impaired development of the male urogenital papilla. Fish exposed to 0.03% v/v sewage effluent produced more fertile eggs than those exposed to 0.3% effluent, or those receiving no effluent. It is concluded that male vitellogenesis in an oestrogenically exposed population may be accompanied by reduced reproductive success, but that it may not be indicative of altered reproductive output in a population exposed to an industrial sewage effluent

Habitat selection of two gobies (Microgobius gulosus, Gobiosoma robustum): influence of structural complexity, competitive interactions and presence of a predator

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Schofield, P.J.

2003-01-01

Herein I compare the relative importance of preference for structurally complex habitat against avoidance of competitors and predators in two benthic fishes common in the Gulf of Mexico. The code goby Gobiosoma robustum Ginsburg and clown goby Microgobius gulosus (Girard) are common, ecologically similar fishes found throughout the Gulf of Mexico and in the southeastern Atlantic Ocean. In Florida Bay, these fishes exhibit habitat partitioning: G. robustum is most abundant in seagrass-dominated areas while M. gulosus is most abundant in sparsely vegetated habitats. In a small-scale field survey, I documented the microhabitat use of these species where their distributions overlap. In a series of laboratory experiments, I presented each species with structured (artificial seagrass) versus nonstructured (bare sand) habitats and measured their frequency of choosing either habitat type. I then examined the use of structured versus nonstructured habitats when the two species were placed together in a mixed group. Finally, I placed a predator (Opsanus beta) in the experimental aquaria to determine how its presence influenced habitat selection. In the field, G. robustum was more abundant in seagrass and M. gulosus was more abundant in bare mud. In the laboratory, both species selected grass over sand in allopatry. However, in sympatry, M. gulosus occupied sand more often when paired with G. robustum than when alone. G. robustum appears to directly influence the habitat choice of M. gulosus: It seems that M. gulosus is pushed out of the structured habitat that is the preferred habitat of G. robustum. Thus, competition appears to modify the habitat selection of these species when they occur in sympatry. Additionally, the presence of the toadfish was a sufficient stimulus to provoke both M. gulosus and G. robustum to increase their selection for sand (compared to single-species treatments). Distribution patterns of M. gulosus and G. robustum

Interspecific variation of ontogeny and skull shape among porpoises (Phocoenidae).

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Galatius, Anders; Berta, Annalisa; Frandsen, Marie Schou; Goodall, R Natalie P

2011-02-01

All extant members of Phocoenidae (porpoises) have been characterized as pedomorphic based on skeletal characters. To investigate the ontogenetic background for pedomorphosis and assess interspecific differences in ontogeny among phocoenids, samples of the six extant species were compared in terms of development of both epiphyseal and cranial suture fusion. Across all species, full maturity of the vertebral column was rare. Vertebral epiphyseal development did not progress so far in most Phocoena phocoena as in Phocoenoides dalli and Phocoena dioptrica. P. phocoena, Phocoena spinipinnis, Ph. dalli, and P. dioptrica, for which large series were available, were further compared in terms of ontogeny of cranial shape by three-dimensional geometric morphometrics. Ph. dalli and P. dioptrica generally showed further development of cranial sutures than the other species. Postnatal skull shape development was similar for all species studied; the majority of interspecific shape differences are present at parturition. Smaller species had a higher rate of shape development relative to growth in size than Ph. dalli and P. dioptrica, but they still showed less allometric development due to less postnatal growth. Interspecific shape differences indicate phylogenetic relationships similar to that proposed based on morphology or convergent evolution of the two pelagic species, Ph. dalli and P. dioptrica, under the scenarios suggested by recent molecular studies. A shape trend coinciding with habitat preference was detected; in species with pelagic preference the position and orientation of the foramen magnum aligned the skull with the vertebral column; the rostrum showed less ventral inclination, and the facial region was larger and more concave in lateral aspect. Copyright © 2010 Wiley-Liss, Inc.

Mammalian Survey Techniques for Level II Natural Resource Inventories on Corps of Engineers Projects (Part 1)

Science.gov (United States)

2009-07-01

sheep (Ovis dalli dalli), mountain goats (Oreamnos americanus) and other hoofed animals are often surveyed using aerial counts from fixed-wing...Society Bulletin 34:69-73. Hilty, J. A., and A. M. Merenlender. 2004. Use of riparian corridors and vineyards by mammalian preda- tors in northern...Witmer, and R. M. Engeman. 2004. Feral swine impacts on agriculture and the environment. Sheep and Goat Research Journal 19:34-40. Slade, N. A., and

Getting what is served? Feeding ecology influencing parasite-host interactions in invasive round goby Neogobius melanostomus.

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Emde, Sebastian; Kochmann, Judith; Kuhn, Thomas; Plath, Martin; Klimpel, Sven

2014-01-01

Freshwater ecosystems are increasingly impacted by alien invasive species which have the potential to alter various ecological interactions like predator-prey and host-parasite relationships. Here, we simultaneously examined predator-prey interactions and parasitization patterns of the highly invasive round goby (Neogobius melanostomus) in the rivers Rhine and Main in Germany. A total of 350 N. melanostomus were sampled between June and October 2011. Gut content analysis revealed a broad prey spectrum, partly reflecting temporal and local differences in prey availability. For the major food type (amphipods), species compositions were determined. Amphipod fauna consisted entirely of non-native species and was dominated by Dikerogammarus villosus in the Main and Echinogammarus trichiatus in the Rhine. However, the availability of amphipod species in the field did not reflect their relative abundance in gut contents of N. melanostomus. Only two metazoan parasites, the nematode Raphidascaris acus and the acanthocephalan Pomphorhynchus sp., were isolated from N. melanostomus in all months, whereas unionid glochidia were only detected in June and October in fish from the Main. To analyse infection pathways, we examined 17,356 amphipods and found Pomphorhynchus sp. larvae only in D. villosus in the river Rhine at a prevalence of 0.15%. Dikerogammarus villosus represented the most important amphipod prey for N. melanostomus in both rivers but parasite intensities differed between rivers, suggesting that final hosts (large predatory fishes) may influence host-parasite dynamics of N. melanostomus in its introduced range.

Mapping of wind energy potential over the Gobi Desert in Northwest China based on multiple sources of data

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Li, Li; Wang, Xinyuan; Luo, Lei; Zhao, Yanchuang; Zong, Xin; Bachagha, Nabil

2018-06-01

In recent years, wind energy has been a fastgrowing alternative source of electrical power due to its sustainability. In this paper, the wind energy potential over the Gobi Desert in Northwest China is assessed at the patch scale using geographic information systems (GIS). Data on land cover, topography, and administrative boundaries and 11 years (2000‒2010) of wind speed measurements were collected and used to map and estimate the region's wind energy potential. Based on the results, it was found that continuous regions of geographical potential (GeoP) are located in the middle of the research area (RA), with scattered areas of similar GeoP found in other regions. The results also show that the technical potential (TecP) levels are about 1.72‒2.67 times (2.20 times on average) higher than the actual levels. It was found that the GeoP patches can be divided into four classes: unsuitable regions, suitable regions, more suitable regions, and the most suitable regions. The GeoP estimation shows that 0.41 billion kW of wind energy are potentially available in the RA. The suitable regions account for 25.49%, the more suitable regions 24.45%, and the most suitable regions for more than half of the RA. It is also shown that Xinjiang and Gansu are more suitable for wind power development than Ningxia.

Southern limits of distribution of the intertidal gobies Chaenogobius annularis and C. gulosus support the existence of a biogeographic boundary in southern Japan (Teleostei, Perciformes, Gobiidae

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Atsunobu Murase

2017-12-01

Full Text Available Understanding the distributional patterns of individual animal groups with respect to coastal topology and the local physical environment provides essential foundational frameworks for marine zoogeography. In the northwestern Pacific waters of Japan, the distributional pattern of some cool-temperate species of marine fishes suggests the existence of a biogeographic boundary corresponding to a long sandy shore on the eastern coast of Kyushu, southern Japan. The existence of this hypothetical biogeographic boundary was tested by mapping the southern distributional limit of two species of cool-temperate intertidal gobies, Chaenogobius annularis and C. gulosus, which are endemic to East Asia and common in rock pools within their range in the Japanese Archipelago. Distribution and abundance were assessed by survey of museum collections from south-east Kyushu (i.e., the entire coasts of Kagoshima and Miyazaki prefectures; and a quantitative survey of the abundance of these gobies in rock pools at various sites around the hypothesized boundary on the eastern coast of Kyushu, including the subtropical Tanega-shima Island. The museum collection survey showed different distribution patterns between the two species: C. annularis was distributed along the entire coasts of south-east Kyushu including subtropical islands, whereas C. gulosus was distributed along these coasts, including one site on a subtropical island, except for an area south of the hypothesized boundary on the eastern coast of Kyushu. The density and occurrence rates of C. annularis in rock pools decreased with latitude, it being absent from a subtropical island, and C. gulosus was not detected from sites south of the hypothesized boundary. The qualitative survey showed that the southernmost records of C. annularis and C. gulosus were the adjacent subtropical islands (Yaku-shima and Tanega-shima islands respectively, although the quantitative survey suggested that their normal range of

First field-based observations of δ2H and δ18O values of precipitation and other water bodies in the Mongolian Gobi desert

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Burnik Šturm, Martina; Ganbaatar, Oyunsaikhan; Voigt, Christian C.; Kaczensky, Petra

2017-04-01

Hydrogen (δ2H) and oxygen (δ18O) isotope values of water are widely used to track the global hydrological cycle and the global δ2H and δ18O patterns of precipitation are increasingly used in studies on animal migration, forensics, food authentication and traceability studies. However, δ2H and δ18O values of precipitation spanning one or more years are available for only a few 100 locations worldwide and for many remote areas such as Mongolia data are still scarce. We obtained the first field-based δ2H and δ18O isotope data of event-based precipitation, rivers and other water bodies in the extreme environment of the Dzungarian Gobi desert in SW Mongolia, covering a period of 16 months (1). Our study area is located over 450 km north-east from the nearest IAEA GNIP station (Fukang station, China) from which it is separated by a mountain range at the international border between China and Mongolia. Isotope values of the collected event-based precipitation showed and extreme range and a high seasonal variability with higher and more variable values in summer and lower in winter. The high variability could not be explained by different origin of air masses alone (i.e. NW polar winds over Russia or westerlies over Central Asia; analyzed using back-trajectory HYSPLIT model), but is likely a result of a combination of different processes affecting the isotope values of precipitation in this area. The calculated field-based local meteoric water line (LMWL, δ2H=(7.42±0.16)δ18O-(23.87±3.27)) showed isotopic characteristics of precipitation in an arid region. We observed a slight discrepancy between the filed based and modelled (Online Isotope in Precipitation Calculator, OIPC) LMWL which highlighted the difficulty of modelling the δ2H and δ18O values for areas with extreme climatic conditions and thus emphasized the importance of collecting long-term field-based data. The collected isotopic data of precipitation and other water bodies provide a basis for future

Stress and serial adult metamorphosis: Multiple roles for the stress axis in socially regulated sex change

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Tessa K Solomon-Lane

2013-11-01

Full Text Available Socially regulated sex change in teleost fishes is a striking example of social status information regulating biological function in the service of reproductive success. The establishment of social dominance in sex changing species is translated into a cascade of changes in behavior, physiology, neuroendocrine function, and morphology that transforms a female into a male, or vice versa. The hypothalamic-pituitary-interrenal axis (HPI, homologous to HP-adrenal axis in mammals and birds has been hypothesized to play a mechanistic role linking status to sex change. The HPA/I axis responds to environmental stressors by integrating relevant external and internal cues and coordinating biological responses including changes in behavior, energetics, physiology, and morphology (i.e., metamorphosis. Through actions of both corticotropin-releasing factor and glucocorticoids (GCs, the HPA/I axis has been implicated in processes central to sex change, including the regulation of agonistic behavior, social status, energetic investment, and life history transitions. In this paper, we review the hypothesized roles of the HPA/I axis in the regulation of sex change and how those hypotheses have been tested to date. We include original data on sex change in the bluebanded goby (Lythyrpnus dalli, a highly social fish capable of bidirectional sex change. We then propose a model for HPA/I involvement in sex change and discuss how these ideas might be tested in the future. Understanding the regulation of sex change has the potential to elucidate evolutionarily conserved mechanisms responsible for translating pertinent information about the environment into coordinated biological changes along multiple body axes.

Stress and serial adult metamorphosis: multiple roles for the stress axis in socially regulated sex change.

Science.gov (United States)

Solomon-Lane, Tessa K; Crespi, Erica J; Grober, Matthew S

2013-01-01

Socially regulated sex change in teleost fishes is a striking example of social status information regulating biological function in the service of reproductive success. The establishment of social dominance in sex changing species is translated into a cascade of changes in behavior, physiology, neuroendocrine function, and morphology that transforms a female into a male, or vice versa. The hypothalamic-pituitary-interrenal axis (HPI, homologous to HP-adrenal axis in mammals and birds) has been hypothesized to play a mechanistic role linking status to sex change. The HPA/I axis responds to environmental stressors by integrating relevant external and internal cues and coordinating biological responses including changes in behavior, energetics, physiology, and morphology (i.e., metamorphosis). Through actions of both corticotropin-releasing factor and glucocorticoids, the HPA/I axis has been implicated in processes central to sex change, including the regulation of agonistic behavior, social status, energetic investment, and life history transitions. In this paper, we review the hypothesized roles of the HPA/I axis in the regulation of sex change and how those hypotheses have been tested to date. We include original data on sex change in the bluebanded goby (Lythyrpnus dalli), a highly social fish capable of bidirectional sex change. We then propose a model for HPA/I involvement in sex change and discuss how these ideas might be tested in the future. Understanding the regulation of sex change has the potential to elucidate evolutionarily conserved mechanisms responsible for translating pertinent information about the environment into coordinated biological changes along multiple body axes.

A new record of Ratan goby - Ponticola ratan (Nordmann, 1840 (Pisces: Gobiidae in the Black Sea, Romanian coastal waters

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Daniel Cocan

2016-11-01

Full Text Available In August 2015 we managed to capture a specimen of ratan goby (Ponticola ratan in the Romanian coastal waters of the Black Sea, near the locality of Sf. Gheorghe (Tulcea County. This is the 7-th signaling for this species in Romanian coastal waters. The previous 6 specimens were recorded in the period 1960-1993, between Mangalia (Constanţa County and Sulina (Tulcea County. The species was identified by means of meristic characters (number of scales on medial line, number of spiny and soft rays, and morphological particularities (cycloid scales on the nape area and pectoral fin joint. Also, the measurements made, confirmed that the ratio between the head length and total length, which was 33% (TL=8.70 cm vs. Head Length=2.61cm. Another morphological character, specific to this species, is the lower jaw, which exceeds in length the upper jaw. Being a Ponto-Caspian endemite, with low population along the Bulgarian and Romanian coastline, we considered it important to point out this new record. Noting that, being known the trend of sporadic migration of this species, would not be excluded that global warming causes a shift from its normal distribution area, from northern and northeastern (Black Sea to south-west. Therefore, future research may bring more notifications regarding this species in south-western area of the Black Sea

Comparison of the Visual Capabilities of an Amphibious and an Aquatic Goby That Inhabit Tidal Mudflats.

Science.gov (United States)

Takiyama, Tomo; Hamasaki, Sawako; Yoshida, Masayuki

2016-01-01

The mudskipper Periophthalmus modestus and the yellowfin goby Acanthogobius flavimanus are gobiid teleosts that both inhabit the intertidal mudflats in estuaries. While P. modestus has an amphibious lifestyle and forages on the exposed mudflat during low tide, the aquatic A. flavimanus can be found at the same mudflat at high tide. This study primarily aimed to elucidate the differential adaptations of these organisms to their respective habitats by comparing visual capacities and motor control in orienting behavior during prey capture. Analyses of retinal ganglion cell topography demonstrated that both species possess an area in the dorsotemporal region of the retina, indicating high acuity in the lower frontal visual field. Additionally, P. modestus has a minor area in the nasal portion of the retina near the optic disc. The horizontally extended specialized area in P. modestus possibly reflects the need for optimized horizontal sight on the exposed mudflat. Behavioral experiments to determine postural and eye direction control when orienting toward the object of interest revealed that these species direct their visual axes to the target situated below eye level just before a rapid approach toward it. A characteristic feature of the orienting behavior of P. modestus was that they aimed at the target by using the specialized retinal area by rotating the eye and lifting the head before jumping to attack the target located above eye level. This behavior could be an adaptation to a terrestrial feeding habitat in which buoyancy is irrelevant. This study provides insights into the adaptive mechanisms of gobiid species and the evolutionary changes enabling them to forage on land. © 2016 S. Karger AG, Basel.

EFFECTS OF DIFFERENT TYPES OF FEED ON GROWTH, SURVIVAL AND DIGESTIVE ENZYME ACTIVITY OF EARLY JUVENILE-STAGE MARBLE GOBY, Oxyeleotris marmoratus

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Muhammad Darwis

2008-06-01

Full Text Available The stable mass seed production technique of marble goby, Oxyeleotris marmoratus has not yet been established due to high mortality occurring on the early juvenile stage and/or after 40 days after hatching (d AH. In order to establish the mass seed production technique, O. marmoratus juveniles of 40 d AH were reared for 60 days to determine growth, survival and digestive enzyme activity at different types of feed (trash fish, artificial feed and Artemia sp. nauplii. Specific growth rate (5.32 and survival rate (91.3% in juveniles fed Artemia sp. nauplii showed significantly higher (P<0.05 than those of juveniles fed trash fish and artificial feed. At the end of the experiment, the mean specific trypsin, amylase and lipase activities of juveniles fed Artemia sp. nauplii were recorded as 0.04 mU mg protein-1m-1, 0.114 mg maltose mg protein-1h-1 and 9.58 m Units, respectively, and they were significantly higher than those of juveniles fed trash fish and artificial feed. In the present study it was shown that O. marmoratus early juveniles had more efficient digestibility and absorption the nutrient when fed with Artemia.

Invasion strategy and abiotic activity triggers for non-native gobiids of the River Rhine.

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Jan Baer

Full Text Available The 24 hour activity patterns of three non-native gobiids (round goby Neogobius melanostomus, Western tubenose goby Proterorhinus semilunaris and bighead goby Ponticola kessleri were assessed over 46 consecutive months between 2011 and 2014 from their occurrence in the cooling water intake of a nuclear power plant on the River Rhine, Germany. In total, 117717 gobiids were identified and classified. The occurrence of all three species varied strongly between sampling years, and species-specific activity triggers were identified. The activity of juveniles of all three gobiids species was positively temperature dependent while adult tubenose goby activity appeared to be negatively temperature dependent. Increasing fluvial discharge in the adjoining main river stimulated the activity of juvenile round goby but inhibited activity of adult tubenose goby. Except for adult bighead goby, activity was also structured by time of day, but with no uniform mean. Meteorological factors such as precipitation, air pressure and duration of sunshine hours had little or no influence on gobiid activity. On selected rare occasions, mainly at night, all three species exhibited pulsed swarming behaviour, with thousands of individuals recorded in the intake water. Round goby swarms exhibited both the highest intensity and the largest swarming individuals, suggesting a potential competitive advantage over tubenose and bighead goby. Electric fishing surveys in natural river stretches corroborated this observation. Negative effects on the native fish fauna were apparent only for the bullhead, Cottus gobio. The activity triggers identified offer a unique insight into the invasion mechanisms of these ecosystem-changing non-native gobiids.

Survival, growth and stress response of juvenile tidewater goby, Eucyclogobius newberryi, to interspecific competition for food

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Chase, Daniel A; Flynn, Erin E; Todgham, Anne E

2016-01-01

Abstract Reintroduction of endangered fishes to historic habitat has been used as a recovery tool; however, these fish may face competition from other fishes that established in their native habitat since extirpation. This study investigated the physiological response of tidewater goby, Eucyclogobius newberryi, an endangered California fish, when competing for food with threespine stickleback, Gasterosteus aculeatus, a native species, and rainwater killifish, Lucania parva, a non-native species. Survival, growth and physiological indicators of stress (i.e. cortisol, glucose and lactate concentrations) were assessed for juvenile fish held for 28 days in two food-limited conditions. When fed a 75% ration, survival of E. newberryi was significantly lower when held with G. aculeatus. In all fish assemblages, weight and relative condition decreased then stabilized over the 28 day experiment, while length remained unchanged. Whole-body cortisol in E. newberryi was not affected by fish assemblage; however, glucose and lactate concentrations were significantly higher with conspecifics than with other fish assemblages. When fed a 50% ration, survival of E. newberryi decreased during the second half of the experiment, while weight and relative condition decreased and length remained unchanged in all three fish assemblages. Cortisol concentrations were significantly higher for all fish assemblages compared with concentrations at the start of the experiment, whereas glucose and lactate concentrations were depressed relative to concentrations at the start of the experiment, with the magnitude of decrease dependent on the species assemblage. Our findings indicate that E. newberryi exhibited reduced growth and an elevated generalized stress response during low food availability. In response to reduced food availability, competition with G. aculeatus had the greatest physiological effect on E. newberryi, with minimal effects from the non-native L. parva. This study presents

Use of Water Balance and Tracer-Based Approaches to Monitor Groundwater Recharge in the Hyper-Arid Gobi Desert of Northwestern China

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Tomohiro Akiyama

2018-05-01

Full Text Available The groundwater recharge mechanism in the hyper-arid Gobi Desert of Northwestern China was analyzed using water balance and tracer-based approaches. Investigations of evaporation, soil water content, and their relationships with individual rainfall events were conducted from April to August of 2004. Water sampling of rainwater, groundwater, and surface water was also conducted. During this period, 10 precipitation events with a total amount of 41.5 mm, including a maximum of 28.9 mm, were observed. Evaporation during the period was estimated to be 33.1 mm. Only the soil water, which was derived from the heaviest precipitation, remained in the vadose zone. This is because a dry surface layer, which was formed several days after the heaviest precipitation event, prevented evaporation. Prior to that, the heaviest precipitation rapidly infiltrated without being affected by evaporation. This is corroborated by the isotopic evidence that both the heaviest precipitation and the groundwater retained no trace of significant kinetic evaporation. Estimated δ-values of the remaining soil water based on isotopic fractionation and its mass balance theories also demonstrated no trace of kinetic fractionation in the infiltration process. Moreover, stable isotopic compositions of the heaviest precipitation and the groundwater were very similar. Therefore, we concluded that the high-intensity precipitation, which rapidly infiltrated without any trace of evaporation, was the main source of the groundwater.

Serum osmolality and ions, and gill Na+/K+-ATPase of spottedtail goby Synechogobius ommaturus (R. in response to acute salinity changes

Directory of Open Access Journals (Sweden)

Chun Shui

2018-03-01

Full Text Available This study was carried out to determine the effects of abrupt salinity change on osmoregulatory ability of the spottedtail goby Synechogobius ommaturus. 720 juvenile fish (65.3 ± 11.8 g were transferred to 200 L tanks (with 40 juveniles in each tank, in which salinities were abruptly changed from 10 to 20, 30, 40, 50 and freshwater. Survival rate, serum osmolality, electrolytes (Na+, Cl−, and K+ and gill Na+/K+-ATPase (NKA activity were assessed successively in 528 h. Results showed serum osmolality, ion concentrations and gill Na+/K+-ATPase activity increased significantly when fish were transferred to salinity 40 and 50 and all fish in these groups died by the end of the experiment. Serum osmolality, Na+, Cl− and K+ in fish transferred to a salinity of 20, 30 and freshwater were not affected and no mortality was detected. Compared with the control group, a significantly decrease of NKA activity happened in the freshwater group, but the activity in 20 and 30 groups was not affected significantly. The results indicated that S. ommaturus could adapt rapidly and maintain homeostasis in a wide range of salinities (from freshwater to salinity 30 and this species may be suitable for aquaculture in estuarine and coastal areas where rapid salinity fluctuations commonly occur. Keywords: Osmolality, Gill, Na+/K+-ATPase, Synechogobius ommaturus

Ameliorating effects of goby fish protein hydrolysates on high-fat-high-fructose diet-induced hyperglycemia, oxidative stress and deterioration of kidney function in rats.

Science.gov (United States)

Nasri, Rim; Abdelhedi, Ola; Jemil, Ines; Daoued, Ines; Hamden, Khaled; Kallel, Choumous; Elfeki, Abdelfattah; Lamri-Senhadji, Myriem; Boualga, Ahmed; Nasri, Moncef; Karra-Châabouni, Maha

2015-12-05

This study investigated the therapeutic potential of undigested goby fish (Zosterisessor ophiocephalus) muscle proteins (UGP) and their hydrolysates on high-fat-high-fructose diet (HFFD)-fed rats. HFFD induced hyperglycemia, manifested by a significant increase in the levels of glucose and glycogen as well as α-amylase activity when compared to normal rats. The administration of GPHs to HFFD-fed rats significantly decreased α-amylase activity and the contents of blood glucose and hepatic glycogen. By contrast, the UGP increased the glucose metabolic disorders in HFFD-fed rats. Furthermore, HFFD-fed rats showed oxidative stress, as evidenced by decreased antioxidant enzyme activities and glutathione (GSH) levels and increased concentration of the lipid peroxidation product malondialdehyde in liver and kidney. Interestingly, the daily gavage of UGP and GPHs improved the redox status in liver and kidney of HFFD-rats by ameliorating or reversing the above-mentioned changes. Moreover, GPHs exhibited a renal protective role by reversing the HFFD-induced decease of uric acid and increase of creatinine levels in serum and preventing some HFFD-induced changes in kidney architecture. The results demonstrate that GPHs contain bioactive peptides that possess significant hypoglycemic and antioxidant properties, and ameliorate renal damage in rats fed hypercaloric diet. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Visible-light photocatalytic activity of graphene oxide-wrapped Bi2WO6 hierarchical microspheres

Science.gov (United States)

Zhai, Jiali; Yu, Hongwen; Li, Haiyan; Sun, Lei; Zhang, Kexin; Yang, Hongjun

2015-07-01

A facile approach of fabricating homogeneous graphene oxide (GO)-wrapped Bi2WO6 microspheres (GO/Bi2WO6) is developed. The transmission electron microscopy (TEM) results show that a heterojunction interface between GO and Bi2WO6. The UV-vis diffuse reflection spectra (DRS) reveal that the as-prepared GO/Bi2WO6 composites own more intensive absorption in the visible light range compared with pure Bi2WO6. These characteristic structural and optical properties endow GO/Bi2WO6 composites with enhanced photocatalytic activity. The enhanced photocatalytic activity of the GO/Bi2WO6 is attributed predominantly to the synergetic effect between GO and Bi2WO6, causing rapid generation and separation of photo-generated charge carriers.

A Field Observation of Rotational Feeding by Neogobius melanostomus

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Ted R. Angradi

2018-01-01

Full Text Available Neogobius melanostomus, the round goby, was recorded by underwater video feeding on crushed dreissenid mussels at a depth of 12 m in Georgian Bay of Lake Huron, a Laurentian Great Lake. In the video, gobies used rotational or twist feeding to tear away particles from crushed mussels. At least 43 examples of this feeding maneuver occur in the video. Up to 120 gobies m−2 were visible at a time in the video. Mean standard length of gobies appearing in the video was 37 mm. Mean standard length of fish exhibiting twist feeding was larger, 48 mm. Mean size of intact mussels in visible clusters was about 10 × 20 mm, a size which exceeds the gape width of the largest gobies observed in the video. Neogobius melanostomus is known to use twisting to wrest small attached mussels from the substrates which can be crushed by their pharyngeal teeth. I surmise that the behavior observed in the video is an opportunistic manifestation of this inherent behavioral adaptation to overcome gap limitation and exploit a temporary windfall of food.

Vigorous dynamics underlie a stable population of the endangered snow leopard Panthera uncia in Tost Mountains, South Gobi, Mongolia.

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Koustubh Sharma

Full Text Available Population monitoring programmes and estimation of vital rates are key to understanding the mechanisms of population growth, decline or stability, and are important for effective conservation action. We report, for the first time, the population trends and vital rates of the endangered snow leopard based on camera trapping over four years in the Tost Mountains, South Gobi, Mongolia. We used robust design multi-season mark-recapture analysis to estimate the trends in abundance, sex ratio, survival probability and the probability of temporary emigration and immigration for adult and young snow leopards. The snow leopard population remained constant over most of the study period, with no apparent growth (λ = 1.08+-0.25. Comparison of model results with the "known population" of radio-collared snow leopards suggested high accuracy in our estimates. Although seemingly stable, vigorous underlying dynamics were evident in this population, with the adult sex ratio shifting from being male-biased to female-biased (1.67 to 0.38 males per female during the study. Adult survival probability was 0.82 (SE+-0.08 and that of young was 0.83 (SE+-0.15 and 0.77 (SE +-0.2 respectively, before and after the age of 2 years. Young snow leopards showed a high probability of temporary emigration and immigration (0.6, SE +-0.19 and 0.68, SE +-0.32 before and after the age of 2 years though not the adults (0.02 SE+-0.07. While the current female-bias in the population and the number of cubs born each year seemingly render the study population safe, the vigorous dynamics suggests that the situation can change quickly. The reduction in the proportion of male snow leopards may be indicative of continuing anthropogenic pressures. Our work reiterates the importance of monitoring both the abundance and population dynamics of species for effective conservation.

Microhabitat Association of Cryptobenthic Reef Fishes (Teleostei: Gobiidae) in the Central Red Sea

KAUST Repository

Troyer, Emily

2018-05-01

Knowledge of biodiversity within an ecosystem is essential when trying to understand the function and importance of that ecosystem. A challenge when assessing biodiversity of reef habitats is cryptobenthic fishes, which encompass many groups that have close associations with the substrate. These fishes can be behaviorally cryptic, by seeking refuge within the reef matrix, or visually cryptic, using cryptic coloration to match the surrounding habitat. These factors make visual surveys inadequate for sampling these fishes. One such group of cryptobenthic fishes are the gobies, family Gobiidae, which currently represent over 1600 species, although new species are continually being discovered. Gobies are often small (less than 5 cm), and many species will be associated with a very specific microhabitat type. Due to the understudied nature of the Red Sea, little is known about habitat preferences of gobies within the region. In order to determine the differences in goby community structure within the central Red Sea, fishes were sampled at one reef using 1 m² enclosed rotenone stations from three distinct microhabitats: hard coral, rubble, and sand. Following collection, specimens were photographed and sequenced using COI, to aid in species identification. 232 individuals were collected representing 31 species of goby. Rubble microhabitats were found to host the majority of collected gobies (69%), followed by hard coral (20.6%), then sand (9.9%). Goby assemblages in the three microhabitats were significantly different from each other, and evidence of habitat-specialists was found. These results provide essential baseline information about the ecology of understudied cryptobenthic fishes that can be used in future large-scale studies in the Red Sea region.

Gut content analysis of Lake Michigan waterbirds in years with avian botulism type E mortality, 2010–2012

Science.gov (United States)

Essian, David A.; Chipault, Jennifer G.; Lafrancois, Brenda M.; Leonard, Jill B.K.

2016-01-01

Waterbird die-offs caused by Clostridium botulinum neurotoxin type E (BoNT/E) have occurred sporadically in the Great Lakes since the late 1960s, with a recent pulse starting in the late 1990s. In recent die-offs, round gobies (Neogobius melanostomus) have been implicated as vectors for the transfer of BoNT/E to fish-eating birds due to the round goby invasion history and their importance as prey. Dreissenid mussels (Dreissena spp.) are also potentially involved in BoNT/E transmission to birds and round gobies. We examined gut contents of waterbirds collected in Lake Michigan during die-offs in 2010–2012, and the gut contents of culled, presumably BoNT/E-free double-crested cormorants (Phalacrocorax auritus). Round gobies were found in 86% of the BoNT/E-positive individuals, 84% of the BoNT/E-negative birds, and 94% of the BoNT/E-free cormorants examined. Double-crested cormorants, ring-billed gulls (Larus delewarensis), and common loons (Gavia immer) consumed larger-sized round gobies than horned and red-necked grebes (Podiceps auritus and Podiceps grisegena), white-winged scoters (Melanitta deglandi), and long-tailed ducks (Clangula hymealis). Other common prey included dreissenid mussels, terrestrial insects, and alewives (Alosa pseudoharengus). Our data emphasize the importance of round gobies and mussels in diets of Lake Michigan waterbirds and suggest they may play a role in the transfer of BoNT/E to waterbirds; however, round gobies and mussels were found in BoNT/E-positive, -negative, and -free individuals, suggesting that other factors, such as alternative trophic pathways for toxin transfer, bird migratory timing and feeding locations, prey behavior, and individual physiological differences across birds may affect the likelihood that a bird will succumb to BoNT/E intoxication.

The Effect of Microclimates in the Aeolian Sand Environment at the Mogao Grottoes, China

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Guo Shuai Li

2013-01-01

Full Text Available To study the micro-meteorological effects of different underlying surfaces of structures to protect the Mogao Grottoes, we analyzed basic meteorological measurements collected at weather stations located in front of the grottoes, on top of the grottoes and in the artificial Gobi. The results show that the shelterbelts in front of the grottoes have a heat-retaining effect. The profile of average daily solar radiation in front of the grottoes forms a sharp peak and the profile in the Gobi forms a parabola, but these patterns vary in different seasons. The artificial Gobi was more susceptible to extremes in temperature and had a faster response and wider response range to ground temperature. The average monthly air temperature, average monthly relative humidity, and the average wind speed in the artificial Gobi tend to first decrease and then increase with measurement height.

Trophic structure and community stability in an overfished ecosystem

KAUST Repository

Utne-Palm, Anne Christine

2010-07-15

Since the collapse of the pelagic fisheries off southwest Africa in the late 1960s, jellyfish biomass has increased and the structure of the Benguelan fish community has shifted, making the bearded goby (Sufflogobius bibarbatus) the new predominant prey species. Despite increased prédation pressure and a harsh environment, the gobies are thriving. Here we show that physiological adaptations and antipredator and foraging behaviors underpin the success of these fish. In particular, body-tissue isotope signatures reveal that gobies consume jellyfish and sulphidic diatomaceous mud, transferring "dead-end" resources back into the food chain.

Trophic structure and community stability in an overfished ecosystem

KAUST Repository

Utne-Palm, Anne Christine; Salvanes, Anne Gro Vea; Currie, Bronwen; Kaartvedt, Stein; Nilsson, Gö ran E.; Braithwaite, Victoria A.; Stecyk, Jonathan A W; Hundt, Matthias; Van Der Bank, Megan G.; Flynn, Bradley A.; Sandvik, Guro Katrine; Klevjer, Thor Aleksander; Sweetman, Andrew K.; Brü chert, Volker; Pittman, Karin A.; Peard, Kathleen R.; Lunde, Ida Gjervold; Strandaba, R. A U; Gibbons, Mark J.

2010-01-01

Since the collapse of the pelagic fisheries off southwest Africa in the late 1960s, jellyfish biomass has increased and the structure of the Benguelan fish community has shifted, making the bearded goby (Sufflogobius bibarbatus) the new predominant prey species. Despite increased prédation pressure and a harsh environment, the gobies are thriving. Here we show that physiological adaptations and antipredator and foraging behaviors underpin the success of these fish. In particular, body-tissue isotope signatures reveal that gobies consume jellyfish and sulphidic diatomaceous mud, transferring "dead-end" resources back into the food chain.

História natural dos amborés e peixes-macaco (Actinopterygii, Blennioidei, Gobioidei do Parque Nacional Marinho do Arquipélago de Fernando de Noronha, sob um enfoque comportamental Natural history focus blennies and gobis behaviour (Actinopterygii, Blennioidei, Gobioidei from Fernando de Noronha Archipelago

Directory of Open Access Journals (Sweden)

Liana de F. Mendes

2006-09-01

Full Text Available Os amborês e peixes-macaco, como são popularmente conhecidos gobiídeos e bleniídeos, são elementos dominantes da fauna de pequenos peixes bentônicos e litorâneos que habitam recifes tropicais, compondo grande parte da alta diversidade das espécies de pequeno porte encontrada no Atlântico ocidental. O estudo da distribuição e história natural dos gobióides e blenióides de Fernando de Noronha foi desenvolvido através de observações de campo. Além da descrição dos hábitats preferenciais foram abordados aspectos sociais tais como, habitat preferencial, interações intra- e interespecíficas, comportamento domiciliar e territorial, e comportamento reprodutivo. A maioria das espécies em foco apresenta distribuição principalmente litorânea, são gregárias, com áreas domiciliares relativamente pequenas em torno de 2 x 2 m², pouco agressivas, tendo sido ocasionalmente registradas curtas perseguições intra- e interespecíficas. A baixa agressividade registrada, em comparação com outros peixes é provavelmente associada à adaptação à ocupação de pequenas áreas, como é o caso das poças de marés, pois um grande número de interações agressivas representaria um gasto de energia desnecessário. No geral, as espécies possuem coloração críptica, associada à evitação de predadores. Apenas nestas épocas de reprodução foi observada a intensificação da agressividade, com comportamento territorial - defesa de território incluindo mordidas e perseguições.The gobis and blenis (Gobiidae and Bleniidae are the most important group of small benthic littoral fishes in tropical reefs, representing most of the high number of small fish species found in Western Atlantic. The natural history of gobiid and bleniid fish from Fernando de Noronha was assessed by means observation sessions using both snorkelling and scuba diving. Most of these observations were aimed at social behaviour, such as intra and interespecific

Formulation de microparticules et de gelules a base de Sida acuta ...

African Journals Online (AJOL)

Formulation de microparticules et de gelules a base de Sida acuta (Malvaceae) par spray drying. A N'guessan, A.A. Koffi, L.I. Dally, K Issoufou, S Any-Grah-Aka, J.A. Lia, A Kouassi-Tuo, K.C. N'guessan-Gnaman ...

Application of otolith shape analysis for stock discrimination and species identification of five goby species (Perciformes: Gobiidae) in the northern Chinese coastal waters

Science.gov (United States)

Yu, Xin; Cao, Liang; Liu, Jinhu; Zhao, Bo; Shan, Xiujuan; Dou, Shuozeng

2014-09-01

We tested the use of otolith shape analysis to discriminate between species and stocks of five goby species ( Ctenotrypauchen chinensis, Odontamblyopus lacepedii, Amblychaeturichthys hexanema, Chaeturichthys stigmatias, and Acanthogobius hasta) found in northern Chinese coastal waters. The five species were well differentiated with high overall classification success using shape indices (83.7%), elliptic Fourier coefficients (98.6%), or the combination of both methods (94.9%). However, shape analysis alone was only moderately successful at discriminating among the four stocks (Liaodong Bay, LD; Bohai Bay, BH; Huanghe (Yellow) River estuary HRE, and Jiaozhou Bay, JZ stocks) of A. hasta (50%-54%) and C. stigmatias (65.7%-75.8%). For these two species, shape analysis was moderately successful at discriminating the HRE or JZ stocks from other stocks, but failed to effectively identify the LD and BH stocks. A large number of otoliths were misclassified between the HRE and JZ stocks, which are geographically well separated. The classification success for stock discrimination was higher using elliptic Fourier coefficients alone (70.2%) or in combination with shape indices (75.8%) than using only shape indices (65.7%) in C. stigmatias whereas there was little difference among the three methods for A. hasta. Our results supported the common belief that otolith shape analysis is generally more effective for interspecific identification than intraspecific discrimination. Moreover, compared with shape indices analysis, Fourier analysis improves classification success during inter- and intra-species discrimination by otolith shape analysis, although this did not necessarily always occur in all fish species.

An eDNA Assay to Monitor a Globally Invasive Fish Species from Flowing Freshwater.

Science.gov (United States)

Adrian-Kalchhauser, Irene; Burkhardt-Holm, Patricia

2016-01-01

Ponto-Caspian gobies are a flock of five invasive fish species that have colonized freshwaters and brackish waters in Europe and North America. One of them, the round goby Neogobius melanostomus, figures among the 100 worst invaders in Europe. Current methods to detect the presence of Ponto-Caspian gobies involve catching or sighting the fish. These approaches are labor intense and not very sensitive. Consequently, populations are usually detected only when they have reached high densities and when management or containment efforts are futile. To improve monitoring, we developed an assay based on the detection of DNA traces (environmental DNA, or eDNA) of Ponto-Caspian gobies in river water. The assay specifically detects invasive goby DNA and does not react to any native fish species. We apply the assay to environmental samples and demonstrate that parameters such as sampling depth, sampling location, extraction protocol, PCR protocol and PCR inhibition greatly impact detection. We further successfully outline the invasion front of Ponto-Caspian gobies in a large river, the High Rhine in Switzerland, and thus demonstrate the applicability of the assay to lotic environments. The eDNA assay requires less time, equipment, manpower, skills, and financial resources than the conventional monitoring methods such as electrofishing, angling or diving. Samples can be taken by untrained individuals, and the assay can be performed by any molecular biologist on a conventional PCR machine. Therefore, this assay enables environment managers to map invaded areas independently of fishermen's' reports and fish community monitorings.

West African Journal of Pharmacology and Drug Research - Vol 25 ...

African Journals Online (AJOL)

Etude de l'amidon d'igname (dioscorea cayenensisrotundata) variete kponan en granulation par vobe humide dans la formulation de comprimes a base de chloroqueve diphosphate. EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. I.I Dally, A Koffi, S Coulibaly.

Diet composition and food consumption rate of harbor porpoises (Phocoena phocoena ) in the western Baltic Sea

DEFF Research Database (Denmark)

Andreasen, Heidi; Ross, Stine Dalmann; Siebert, Ursula

2017-01-01

frequently consumed gobies. Here, the mass contribution by gobies was on aver-age 25%, which was as much as cod. Other species such as whiting, sprat, eelpout, and sandeels were of minor importance for both juveniles and adults. The diet compo- sition differed between years, quarters, and porpoise...

Diversity of gastrointestinal helminths in Dall's sheep and the negative association of the abomasal nematode, Marshallagia marshalli, with fitness indicators.

Science.gov (United States)

Aleuy, O Alejadro; Ruckstuhl, Kathreen; Hoberg, Eric P; Veitch, Alasdair; Simmons, Norman; Kutz, Susan J

2018-01-01

Gastrointestinal helminths can have a detrimental effect on the fitness of wild ungulates. Arctic and Subarctic ecosystems are ideal for the study of host-parasite interactions due to the comparatively simple ecological interactions and limited confounding factors. We used a unique dataset assembled in the early seventies to study the diversity of gastrointestinal helminths and their effect on fitness indicators of Dall's sheep, Ovis dalli dalli, in the Mackenzie Mountains, Northwest Territories, Canada. Parasite diversity included nine species, among which the abomasal nematode Marshallagia marshalli occurred with the highest prevalence and infection intensity. The intensity of M. marshalli increased with age and was negatively associated with body condition and pregnancy status in Dall's sheep across all the analyses performed. The intensity of the intestinal whipworm, Trichuris schumakovitschi, decreased with age. No other parasites were significantly associated with age, body condition, or pregnancy. Our study suggests that M. marshalli might negatively influence fitness of adult female Dall's sheep.

Noise can affect acoustic communication and subsequent spawning success in fish.

Science.gov (United States)

de Jong, Karen; Amorim, M Clara P; Fonseca, Paulo J; Fox, Clive J; Heubel, Katja U

2018-06-01

There are substantial concerns that increasing levels of anthropogenic noise in the oceans may impact aquatic animals. Noise can affect animals physically, physiologically and behaviourally, but one of the most obvious effects is interference with acoustic communication. Acoustic communication often plays a crucial role in reproductive interactions and over 800 species of fish have been found to communicate acoustically. There is very little data on whether noise affects reproduction in aquatic animals, and none in relation to acoustic communication. In this study we tested the effect of continuous noise on courtship behaviour in two closely-related marine fishes: the two-spotted goby (Gobiusculus flavescens) and the painted goby (Pomatoschistus pictus) in aquarium experiments. Both species use visual and acoustic signals during courtship. In the two-spotted goby we used a repeated-measures design testing the same individuals in the noise and the control treatment, in alternating order. For the painted goby we allowed females to spawn, precluding a repeated-measures design, but permitting a test of the effect of noise on female spawning decisions. Males of both species reduced acoustic courtship, but only painted gobies also showed less visual courtship in the noise treatment compared to the control. Female painted gobies were less likely to spawn in the noise treatment. Thus, our results provide experimental evidence for negative effects of noise on acoustic communication and spawning success. Spawning is a crucial component of reproduction. Therefore, even though laboratory results should not be extrapolated directly to field populations, our results suggest that reproductive success may be sensitive to noise pollution, potentially reducing fitness. Copyright © 2017 Elsevier Ltd. All rights reserved.

Linking remote-sensing and ecosystem services modeling to support and assess management for regenerative grazing in the South Gobi, Mongolia

Science.gov (United States)

Chaplin-Kramer, R.; Kowal, V. A.; Sharp, R.

2017-12-01

Managing and monitoring supply chain sustainability is a major challenge and opportunity for business, especially in rangelands, heavily managed and often degraded natural systems that provide significant resources and raw materials for production. One of the largest and most threatened rangeland systems in the world is in Mongolia, which has seen a rapid rise in grazing pressure due to increasing global demand for cashmere along with privatization of a formerly government-run livestock industry. A new opportunity is emerging for remote-sensing to improve the management decisions of the producers and their incentive-setters, leading to a more sustainable rangeland system and better outcomes for biodiversity and people in this unique and imperiled landscape. Oyu Tolgoi (OT), the Mongolian subsidiary of the mining company Rio Tinto, in cooperation with Kering, an apparel conglomerate that sources cashmere from the region, are providing financial incentives to improve grazing patterns through a Sustainable Cashmere program, in order to restore the degraded rangeland ecosystem in the Gobi desert region. We present a framework and approach for predicting the effect of changing grazing practices on biodiversity and ecosystem services, which we are developing into decision-support tools for OT, Kering, and their local partner Wildlife Conservation Society to quantify the impacts of their programs and where these interventions will have greatest benefit. Our approach integrates remote-sensing and ecosystem modeling to scale up field monitoring data and forecast future impacts. Our rangeland production model, based on the soil-vegetation model CENTURY and the livestock model GRAZPLAN, predicts biomass production and plant species composition changes, and can feed into ecosystem services models such as soil retention and water regulation in the InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) software suite. This presents a significant advance in ecosystem

564-IJBCS-Article-Dally Labo Ismaël

African Journals Online (AJOL)

DR GATSING

nouveaux médicaments. On estime que près de 50% des agents thérapeutiques utilisés .... secondes au maximum) sert de mesure d'habituation. La moyenne calculée sur les .... Tableau 1 : Effet de l'extrait aqueux de Mitracarpus scaber et de la morphine sur la latence de retrait de la queue de la souris. Temps de latence ...

COMPARATIVE CHARACTERISTICS OF MORPHOMETRIC PARAMETERS OF MONKEY GOBY (NEOGOBIUS FLUVIATILIS PALLAS OF FRESH AND SALINE WATER RESERVOIRS IN UKRAINE

Directory of Open Access Journals (Sweden)

Onoprienko V.

2014-04-01

physiological processes. The result of this effect is the difference in weight, size and body parts. To clarify, as our model species was taken Cottus Sandpiper (Neogobius fluviatilis Pallas. The reason for this was the fact that this species, along with other Ponto- Caspian solonovato - freshwater gobies, the International Union for Conservation of Nature classified as species biology are poorly understood and require further research. This fact that deepened interest of ichthyologists in this group of fish, in this regard appeared in the literature as material for the bulls and in Sandpiper. Based on the above, the purpose of this paper is a comparative morphometric parameters characteristic of individuals of this species of fresh and salt water bodies of Ukraine. All this affects the absolute morphometric parameters, which decrease in the direction from sea to the river. However, it should be noted that in rivers with rich feeding grounds sheer size of some individuals close to the size and species of sea Kakhovskoe reservoir. This situation is observed in the Sandpiper Grouse River. Here are some specimens reach a length (TL 118-148 mm and a weight of 15-36 g, Kakhovskoe Reservoir: 106-150 mm 11-38 g, in the Sea of Azov: 115-174 mm 17-58 g. For relative parameters Sandpiper with these reservoirs are more similar, however, for some of them, there are differences. Among the latter is most clearly distinguished the ratio SL / N. This indicator podovzhenist (prohonystist body. As pointed out by VP Mitrofanov (1977, this indicator shows the hydrodynamic qualities of fish: the larger the index, the more active lifestyle is individual. When compared with individuals with a little water and a large stream, in the latter case, individuals are more elongated. This is confirmed by our material: the ratio SL / L for the smallest species of sea of Azov (4.96, slightly more for Kakhovsky reservoir (5.52 and even more for rivers Grouse, Trubizh, Desna, Ros (respectively 5, 86, 6.22 , 6

Life cycle assessment and evaluation of energy payback time on high-concentration photovoltaic power generation system

International Nuclear Information System (INIS)

Nishimura, A.; Hayashi, Y.; Tanaka, K.; Hirota, M.; Kato, S.; Ito, M.; Araki, K.; Hu, E.J.

2010-01-01

In this study, the environmental load of photovoltaic power generation system (PV) during its life cycle and energy payback time (EPT) are evaluated by LCA scheme. Two hypothetical case studies in Toyohashi, Japan and Gobi dessert in China have been carried out to investigate the influence of installation location and PV type on environmental load and EPT. The environmental load and EPT of a high-concentration photovoltaic power generation system (hcpV) and a multi-crystalline silicon photovoltaic power generation system (mc-Si PV) are studied. The study shows for a PV of 100 MW size, the total impacts of the hcpV installed in Toyohashi is larger than that of the hcpV installed in Gobi desert by 5% without consideration of recycling stage. The EPT of the hcpV assumed to be installed in Gobi desert is shorter than EPT of the hcpV assumed to be installed in Toyohashi by 0.64 year. From these results, the superiority to install PV in Gobi desert is certificated. Comparing with hcpV and mc-Si PV, the ratio of the total impacts of mc-Si PV to that of hcpV is 0.34 without consideration of recycling stage. The EPT of hcpV is longer than EPT of mc-Si PV by 0.27 year. The amount of global solar radiation contributing to the amount of power generation of mc-Si PV is larger than the amount of direct solar radiation contributing to the amount of power generation of hcpV by about 188 kW h/(m 2 year) in Gobi desert. Consequently, it appears that using mc-Si PV in Gobi desert is the best option.

Characteristics of trophic transfer of polychlorinated biphenyls in marine organisms in Incheon North Harbor, Korea.

Science.gov (United States)

Kim, Seung Kyu; Lee, Dong Soo; Oh, Jae Ryong

2002-04-01

The trophic transfer of polychlorinated biphenyls (PCBs) was characterized for zooplankton (primarily Paracalanus spp. and Acartia spp.), pacific oyster (Crassostrea gigas), shore crab (Hemigrapsus penicillatus), and goby (Acanthogobius hasta) in the aquatic system of Incheon North Harbor, Korea. The congener pattern in the species was clearly divided by the main PCB uptake route. Compared with zooplankton and oyster, the fraction of heavier homologues increased in crab and goby that take PCBs from food. Linear relationships were observed between log (fugacity in lipid/fugacity in seawater) and log Kow for all the species. For zooplankton and oyster, such an observation should not be regarded as a true absence of superhydrophobicity, because establishment of equilibrium with seawater was not evident. For crab and goby, the absence of superhydrophobicity was evidenced by the trophic transfer factor that continuously increased with Kow up to 10(7.8). These results suggest that superhydrophobicity might be species specific. The trophic transfer factors and the fugacity levels in the lipid phase indicated that bioaccumulation in crab and goby advanced beyond the level in equilibrium with seawater in the harbor basin.

Correlation and Fishers’ Perception in Selected Sites in Laguna de Bay, Luzon Island, Philippines

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Arthur J. Lagbas

2017-01-01

Full Text Available White goby (Glossogobius giuris Hamilton 1822 is an omnivorous, native fish species which can be found in Laguna de Bay and its tributaries, and in other bodies of water in the Philippines. Deteriorating water quality, unsustainable fishing practices, aquaculture and predation by introduced invasive species are threatening the population of white goby and other native fish species in Laguna de Bay. This study was conducted to correlate select physico-chemical parameters of lake water and zooplankton abundance, and to assess white goby population based on fishers’ perception. Water samples were collected in three sites in June, September and December 2014. Twenty one zooplankton species belonging to 12 families were identified. The most abundant and frequently encountered zooplankton species is Eurytemora affinis Poppe 1880. Zooplanktons were most abundant in June and lowest in September. Key informant interviews with local fishers revealed that white goby population was abundant in April to August while catch report showed that fish catch is abundant in June and least during December. The fish abundance in April to June could be attributed to high productivity especially in summer season. The fishers perceived that the population of white goby was declining mainly due to water pollution, aquaculture, and predation by invasive alien species. A multi-stakeholder sustainable watershed management should be adapted to improve the water quality and extinction of native fish species in Laguna de Bay.

Otoliths as an integral part in fossil fish taxonomy

Directory of Open Access Journals (Sweden)

Christoph Gierl

2015-11-01

Full Text Available Otoliths are small structures in the skull of fishes. They are responsible for hearing and orientation in the 3-dimensional space. They also hold valuable information regarding the taxonomy. Their outline, the shape of the sulcus and other features allow the determination of a fish even to the species level. A lot of fossil species are solely based on otoliths because of their good chance of preservation. Gobies are in this case no different. An additional challenge in gobies is their high similarity between species concerning the preservable parts. Fossil skeletons that are 20 Million years old can show only few differences compared to recent gobies. These features are often hardly recognizable due to their preservation. As a consequence many fossil gobies have been assigned to the genus Gobius sensu lato. Examples are two gobies from the Miocene of Southern Germany. They have a unique combination of characters (six branchiostegals, palatine resembling a “T”, no entopterygoid that allows the rectification of a new fossil genus but the two species are hardly distinguishable based only on the skeleton. The key hints in having two species are the otoliths. They show slight but consistent differences in their outline. This shows that otoliths can be a key feature in species identification. They should also be taken into consideration by recent fish species. Not to mention their possible phylogenetic potential that remains to be explored.

Genetic analysis reveals the diversity of larval Gobiidae in a temperate estuary.

Science.gov (United States)

Ojaveer, H; Gross, R; Laur, K; Arula, T; Klais, R

2017-10-01

Using molecular tools to examine Gobiidae, the second most abundant taxon in ichthyoplankton samples in the Gulf of Riga (Baltic Sea), the sand goby Pomatoschistus minutus was the most abundant taxon (82% of all individuals analysed), the common goby Pomatoschistus microps constituted 12% and the black goby Gobius niger 6%. The spatiotemporal distribution of P. microps and G. niger indicated a preference for habitats closer to the river inlet and their abundances increased slightly towards the end of the sampling period in summer. The species composition was interpreted in the context of the prevailing habitat conditions, characterized by extremely low water transparency, low salinity, limited spread of vegetated area and dominance of sandy-muddy substrata. © 2017 The Fisheries Society of the British Isles.

Pentagone internalises glypicans to fine-tune multiple signalling pathways

Science.gov (United States)

Norman, Mark; Vuilleumier, Robin; Springhorn, Alexander; Gawlik, Jennifer; Pyrowolakis, George

2016-01-01

Tight regulation of signalling activity is crucial for proper tissue patterning and growth. Here we investigate the function of Pentagone (Pent), a secreted protein that acts in a regulatory feedback during establishment and maintenance of BMP/Dpp morphogen signalling during Drosophila wing development. We show that Pent internalises the Dpp co-receptors, the glypicans Dally and Dally-like protein (Dlp), and propose that this internalisation is important in the establishment of a long range Dpp gradient. Pent-induced endocytosis and degradation of glypicans requires dynamin- and Rab5, but not clathrin or active BMP signalling. Thus, Pent modifies the ability of cells to trap and transduce BMP by fine-tuning the levels of the BMP reception system at the plasma membrane. In addition, and in accordance with the role of glypicans in multiple signalling pathways, we establish a requirement of Pent for Wg signalling. Our data propose a novel mechanism by which morphogen signalling is regulated. DOI: http://dx.doi.org/10.7554/eLife.13301.001 PMID:27269283

The distribution of 4-nonylphenol in marine organisms of North American Pacific Coast estuaries.

Science.gov (United States)

Diehl, Jennifer; Johnson, Sarah E; Xia, Kang; West, Amy; Tomanek, Lars

2012-04-01

One of the chemical breakdown products of nonylphenol ethoxylates, 4-nonylphenol (4-NP), accumulates in organisms and is of concern as an environmental pollutant due to its endocrine disrupting effects. We measured 4-NP levels in the seawater, sediment, and twelve organisms within the California estuary, Morro Bay, and examined biomagnification of 4-NP using stable isotope abundances (δ(15)N and δ(13)C) to quantify trophic position. 4-NP concentrations in organisms from Morro Bay included 25000±8600 ng g(-1) lw in liver of California sea lion, 14000±5600 ng g(-1) lw in liver of harbor porpoise, 138000±55000 ng g(-1) lw in liver of sea otters, 15700±3600 ng g(-1) lw in liver of seabirds, 36100±6100 ng g(-1) lw in arrow goby fish, 62800±28400 ng g(-1) lw in oysters, and 12700±1300 ng g(-1) lw in mussels. 4-NP levels generally showed a pattern of trophic dilution among organisms in Morro Bay, with exceptions of biomagnification observed between three trophic links: mussel to sea otter (BMF 10.9), oyster to sea otter (BMF 2.2), and arrow goby to staghorn sculpin (BMF 2.7). Our examination of other west coast estuaries of USA and Canada revealed that mean 4-NP concentrations in gobies and mussels from Morro Bay were significantly higher than those from a more urbanized estuary, San Francisco Bay (goby: 11100±3800 ng g(-1) lw) and from a remote estuary, Bamfield Inlet, Canada (goby: 9000±900 ng g(-1) lw, mussel: 6100±700 ng g(-1) lw). Relative to other estuaries worldwide, 4-NP levels in seawater (0.42±0.16 μg L(-1)) and sediment (53±14 ng g(-1) dw) of Morro Bay are low, but gobies and oysters have higher 4-NP levels than comparable fauna. Copyright © 2012 Elsevier Ltd. All rights reserved.

Why are marine adaptive radiations rare in Hawai'i?

Science.gov (United States)

Wainwright, Peter C

2015-02-01

Islands can be sites of dynamic evolutionary radiations, and the Hawaiian Islands have certainly given us a bounty of insights into the processes and mechanisms of diversification. Adaptive radiations in silverswords and honeycreepers have inspired a generation of biologists with evidence of rapid diversification that resulted in exceptional levels of ecological and morphological diversity. In this issue of Molecular Ecology, tiny waterfall-climbing gobies make a case for their place among Hawaiian evolutionary elite. Moody et al. (2015) present an analysis of gene flow and local adaptation in six goby populations on Kaua'i and Hawai'i measured in three consecutive years to try to disentangle the relative role of local adaptation and gene flow in shaping diversity within Sicyopterus stimpsoni. Their study shows that strong patterns of local selection result in streams with gobies adapted to local conditions in spite of high rates of gene flow between stream populations and no evidence for significant genetic population structure. These results help us understand how local adaptation and gene flow are balanced in gobies, but these fishes also offer themselves as a model that illustrates why adaptive diversification in Hawai'i's marine fauna is so different from the terrestrial fauna. © 2015 John Wiley & Sons Ltd.

Emission, transport, and radiative effects of mineral dust from the Taklimakan and Gobi deserts: comparison of measurements and model results

Science.gov (United States)

Chen, Siyu; Huang, Jianping; Kang, Litai; Wang, Hao; Ma, Xiaojun; He, Yongli; Yuan, Tiangang; Yang, Ben; Huang, Zhongwei; Zhang, Guolong

2017-02-01

The Weather Research and Forecasting Model with chemistry (WRF-Chem model) was used to investigate a typical dust storm event that occurred from 18 to 23 March 2010 and swept across almost all of China, Japan, and Korea. The spatial and temporal variations in dust aerosols and the meteorological conditions over East Asia were well reproduced by the WRF-Chem model. The simulation results were used to further investigate the details of processes related to dust emission, long-range transport, and radiative effects of dust aerosols over the Taklimakan Desert (TD) and Gobi Desert (GD). The results indicated that weather conditions, topography, and surface types in dust source regions may influence dust emission, uplift height, and transport at the regional scale. The GD was located in the warm zone in advance of the cold front in this case. Rapidly warming surface temperatures and cold air advection at high levels caused strong instability in the atmosphere, which strengthened the downward momentum transported from the middle and low troposphere and caused strong surface winds. Moreover, the GD is located in a relatively flat, high-altitude region influenced by the confluence of the northern and southern westerly jets. Therefore, the GD dust particles were easily lofted to 4 km and were the primary contributor to the dust concentration over East Asia. In the dust budget analysis, the dust emission flux over the TD was 27.2 ± 4.1 µg m-2 s-1, which was similar to that over the GD (29 ± 3.6 µg m-2 s-1). However, the transport contribution of the TD dust (up to 0.8 ton d-1) to the dust sink was much smaller than that of the GD dust (up to 3.7 ton d-1) because of the complex terrain and the prevailing wind in the TD. Notably, a small amount of the TD dust (PM2.5 dust concentration of approximately 8.7 µg m-3) was lofted to above 5 km and transported over greater distances under the influence of the westerly jets. Moreover, the direct radiative forcing induced by dust

Measurement of scattering and absorption properties of dust aerosol in a Gobi farmland region of northwestern China – a potential anthropogenic influence

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J. Bi

2017-06-01

Full Text Available We conducted a comprehensive field campaign to explore the optical characteristics of mineral dust in Dunhuang farmland near the Gobi Desert of northwest China during spring of 2012. The day-to-day and diurnal variations of dust aerosol showed prominent features throughout the experiment, primarily attributable to frequent dust events and local anthropogenic emissions. The overall average mass concentrations of the particulate matter with an aerodynamic diameter less than 10 µm (PM10, light scattering coefficient (σsp, 670, absorption coefficient (σap, 670, and single-scattering albedo (SSA670 were 113 ± 169 µg m−3, 53.3 ± 74.8 Mm−1, 3.2 ± 2.4 Mm−1, and 0.913 ± 0.05, respectively, which were comparable to the background levels in the southern United States but smaller than those in the eastern and other northwestern Chinese cities. The anthropogenic dust produced by agricultural cultivations (e.g., land planning, plowing, and disking exerted a significant superimposed effect on high dust concentrations in Dunhuang farmland prior to the growing season (i.e., from 1 April to 10 May. Strong south valley wind and vertical mixing in daytime scavenged the pollution, and the weak northeast mountain wind and stable inversion layer at night favorably accumulated the air pollutants near the surface. In the afternoon (13:00–18:00 LT, local time, mean SSA670 was 0.945 ± 0.04 predominantly from dust particles, whereas finer particles and lower SSA670 values ( ∼  0.90–0.92 were measured at night, suggesting the potential influence by the mixed dust pollutants. During a typical biomass burning event on 4 April 2012, σap, 670 increased from  ∼  2.0 to 4.75 Mm−1 and SSA670 changed from  ∼  0.90 to  ∼  0.83, implying remarkable modification of aerosol absorptive properties induced by human activities. The findings of this study would help to advance an in

The olfactory receptor gene repertoires in secondary-adapted marine vertebrates: evidence for reduction of the functional proportions in cetaceans

OpenAIRE

Kishida, Takushi; Kubota, Shin; Shirayama, Yoshihisa; Fukami, Hironobu

2007-01-01

An olfactory receptor (OR) multigene family is responsible for the well-developed sense of smell possessed by terrestrial tetrapods. Mammalian OR genes had diverged greatly in the terrestrial environment after the fish–tetrapod split, indicating their importance to land habitation. In this study, we analysed OR genes of marine tetrapods (minke whale Balaenoptera acutorostrata, dwarf sperm whale Kogia sima, Dall's porpoise Phocoenoides dalli, Steller's sea lion Eumetopias jubatus and loggerhea...

Environmental Impact Analysis Process. Draft Environmental Impact Statement Proposed Alaskan Radar System Over-the-Horizon Backscatter Radar Program

Science.gov (United States)

1986-08-01

Mustela vison wolverine Gulo Kulo river otter Lutra canadensis lynx Lynx canadensis moose Alces alces caribou Rangifer tarandus Dall’s sheep Ovic dalli...tissue respiratory chain function at a power density of 5 mW/cm2 . It is unlikely that such effects would be detectable at the power densities at ground...Vulves vulpes black bear Ursus americanus grizzly bear Ursus arctos marten Martes americana ermine Mustela erminea least weasel Mustela nivalis mink

Bottom trawl assessment of Lake Ontario prey fishes

Science.gov (United States)

Weidel, Brian C.; Connerton, Michael J.; Holden, Jeremy

2018-01-01

Managing Lake Ontario fisheries in an ecosystem-context requires prey fish community and population data. Since 1978, multiple annual bottom trawl surveys have quantified prey fish dynamics to inform management relative to published Fish Community Objectives. In 2017, two whole-lake surveys collected 341 bottom trawls (spring: 204, fall: 137), at depths from 8-225m, and captured 751,350 fish from 29 species. Alewife were 90% of the total fish catch while Deepwater Sculpin, Round Goby, and Rainbow Smelt comprised the majority of the remaining total catch (3.8, 3.1, and 1.1% respectively). The adult Alewife abundance index for US waters increased in 2017 relative to 2016, however the index for Canadian waters declined. Adult Alewife condition, assessed by the predicted weight of a 165 mm fish (6.5 inches), declined in 2017 from record high values observed in spring 2016. Spring 2017 Alewife condition was slightly less than the 10-year average, but the fall value was well below the 10-year average, likely due to increased Age-1 Alewife abundance. The Age-1 Alewife abundance index was the highest observed in 40 years, and 8-times higher than the previous year. The Age-1 index estimates Alewife reproductive success the preceding year. The warm summer and winter of 2016 likely contributed to the large year class. In contrast the relatively cool 2017 spring and cold winter may result in a lower than average 2017 year class. Abundance indices for Rainbow Smelt, Cisco, and Emerald Shiner either declined or remained at low levels in 2017. Pelagic prey fish diversity continues to be low since a single species, Alewife, dominates the catch. Deepwater Sculpin were the most abundant benthic prey fish in 2017 because Round Goby abundance declined sharply from 2016. Slimy Sculpin density continued to decline and the 2017 biomass index for US waters was the lowest ever observed. Prior to Round Goby proliferation, juvenile Slimy Sculpin comprised ~10% of the Slimy Sculpin catch, but

Impact of Gobi desert dust on aerosol chemistry of Xi'an, inland China during spring 2009: differences in composition and size distribution between the urban ground surface and the mountain atmosphere

Directory of Open Access Journals (Sweden)

G. H. Wang

2013-01-01

Full Text Available Composition and size distribution of atmospheric aerosols from Xi'an city (~400 m, altitude in inland China during the spring of 2009 including a massive dust event on 24 April were measured and compared with a parallel measurement at the summit (2060 m, altitude of Mt. Hua, an alpine site nearby Xi'an. EC (elemental carbon, OC (organic carbon and major ions in the city were 2–22 times higher than those on the mountaintop during the whole sampling period. Compared to that in the non-dust period a sharp increase in OC was observed at both sites during the dust period, which was mainly caused by an input of biogenic organics from the Gobi desert. However, adsorption/heterogeneous reaction of gaseous organics with dust was another important source of OC in the urban, contributing 22% of OC in the dust event. In contrast to the mountain atmosphere where fine particles were less acidic when dust was present, the urban fine particles became more acidic in the dust event than in the non-dust event, mainly due to enhanced heterogeneous formation of nitrate and diluted NH₃. Cl⁻ and NO₃⁻ in the urban air during the dust event significantly shifted toward coarse particles. Such redistributions were further pronounced on the mountaintop when dust was present, resulting in both ions almost entirely staying in coarse particles. On the contrary, no significant spatial difference in size distribution of SO₄²⁻ was found between the urban ground surface and the mountain atmosphere, which dominated in the fine mode (<2.1 μm during the nonevent and comparably distributed in the fine (<2.1 μm and coarse (>2.1 μm modes during the dust event.

Age and growth of Crystallogobius linearis (von Düben, 1845 (Teleostei: Gobiidae from the Adriatic Sea

Directory of Open Access Journals (Sweden)

M. La Mesa

2001-12-01

Full Text Available Age and growth of the crystal goby Crystallogobius linearis (von Düben, 1845 were investigated by means of daily growth increment counts on the sagittal otoliths. Samples of C. linearis, obtained as by-catch of the Aphia minuta fishery, were collected in a coastal area of the central Adriatic Sea between March and September 1996. Otolith age-readings were carried out on 167 specimens, ranged from 14 to 41 mm of total length, and indicated that the population was composed of individuals from two to seven months old. Growth of both males and females appeared practically linear over the whole size range studied, although in females a slight decrease in growth rate of older specimens was observed. Furthermore, the hatch date distribution of C. linearis, obtained by the backcalculation of the ageing data, indicated a long breeding season of at least eight months. The results of this study indicated that, as reported from literature for most nektonic gobies, the crystal goby is also characterised by a short life span, during which a high reproductive effort is displayed throughout a long breeding season.

The tale of two continents

International Nuclear Information System (INIS)

Ednie, H.

2007-01-01

This article discussed the development of coal resources in Mongolia by Vancouver-based Ivanhoe Mines. SouthGobi Energy Resources is the largest holder of coal lands under exploration in Mongolia, with 2.3 million hectares, comprising 54 exploration licenses. The properties are located in the southern part of Mongolia in the Gobi Desert bordering China. The opportunities for developing coal from Mongolia to be sold to China were summarized. Ovoot Tolgoi is the most advanced of SouthGobi's projects, with 150 million tonnes of coal resources measured and indicated. The initial plan is for the development of a surface mine. A detailed environmental assessment has been completed and approved. The development plans have also been accepted by local communities. Mining equipment will be purchased once the mining license is granted. The operation will start at 1 million tonnes per year, then increase to 5 million tonnes per year in 5 years. The coal is continuous at depth, and plans for an underground operation have already begun. This article also discussed the challenges of conducting business in Mongolia and improving the infrastructure to support the development of mining operations. 3 figs

Morphological selection and the evaluation of potential tradeoffs between escape from predators and the climbing of waterfalls in the Hawaiian stream goby Sicyopterus stimpsoni.

Science.gov (United States)

Blob, Richard W; Kawano, Sandy M; Moody, Kristine N; Bridges, William C; Maie, Takashi; Ptacek, Margaret B; Julius, Matthew L; Schoenfuss, Heiko L

2010-12-01

Environmental pressures may vary over the geographic range of a species, exposing subpopulations to divergent functional demands. How does exposure to competing demands shape the morphology of species and influence the divergence of populations? We explored these questions by performing selection experiments on juveniles of the Hawaiian goby Sicyopterus stimpsoni, an amphidromous fish that exhibits morphological differences across portions of its geographic range where different environmental pressures predominate. Juvenile S. stimpsoni face two primary and potentially opposing selective pressures on body shape as they return from the ocean to freshwater streams on islands: (1) avoiding predators in the lower reaches of a stream; and (2) climbing waterfalls to reach the habitats occupied by adults. These pressures differ in importance across the Hawaiian Islands. On the youngest island, Hawai'i, waterfalls are close to shore, thereby minimizing exposure to predators and placing a premium on climbing performance. In contrast, on the oldest major island, Kaua'i, waterfalls have eroded further inland, lengthening the exposure of juveniles to predators before migrating juveniles begin climbing. Both juvenile and adult fish show differences in body shape between these islands that would be predicted to improve evasion of predators by fish from Kaua'i (e.g., taller bodies that improve thrust) and climbing performance for fish from Hawai'i (e.g., narrower bodies that reduce drag), matching the prevailing environmental demand on each island. To evaluate how competing selection pressures and functional tradeoffs contribute to the divergence in body shape observed in S. stimpsoni, we compared selection imposed on juvenile body shape by (1) predation by the native fish Eleotris sandwicensis versus (2) climbing an artificial waterfall (∼100 body lengths). Some variables showed opposing patterns of selection that matched predictions: for example, survivors of predation had

Fall diets of red-breasted merganser (Mergus serrator) and walleye (Sander vitreus) in Sandusky Bay and adjacent waters of western Lake Erie

Science.gov (United States)

Bur, M.T.; Stapanian, M.A.; Bernhardt, G.; Turner, M.W.

2008-01-01

Although published studies indicate the contrary, there is concern among many sport anglers that migrating red-breasted mergansers (Mergus serrator) and other waterbirds pose a competitive threat to sport fish species such as walleye (Sander vitreus) in Lake Erie. We quantified the diet of autumn-migrant mergansers and walleye during 1998-2000 in Sandusky Bay and adjacent waters of western Lake Erie. We hypothesized that the diets of both predators would be similar in species composition, but because of different foraging ecologies their diets would differ markedly in size of prey consumed. In addition to predator samples, we used trawl data from the same general area as an index of prey availability. We found that mergansers fed almost exclusively on fish (nine species). Gizzard shad (Dorosoma cepedianum), emerald shiner (Notropis atherinoides) and round goby (Neogobius melanostomus) were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Walleye fed exclusively on fish: gizzard shad, alewife (Alosa psuedoharengus) and emerald shiner were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Diet overlap between mergansers and walleye was 67% by weight and 66% by species frequency. Mean total lengths of gizzard shad, emerald shiner and round goby found in walleye stomachs exceeded those captured in trawls by 47%, on average. Mean total lengths of gizzard shad, emerald shiner and round goby were greater in walleye stomachs than in merganser stomachs. Mean total lengths of emerald shiner and round goby were less in merganser stomachs than in trawls. Our results suggest that although the diets of walleye and mergansers overlapped considerably, mergansers generally consumed smaller fish than walleye. Given the abundance and diversity of prey species available, and the transient nature of mergansers on Lake Erie during migration, we conclude that competition for food between these species is minimal.

The circular Uneged Uul structure (East Gobi Basin, Mongolia) - Geomorphic and structural evidence for meteorite impact into an unconsolidated coarse-clastic target?

Science.gov (United States)

Schmieder, Martin; Seyfried, Hartmut; Gerel, Ochir

2013-03-01

The Uneged Uul structure is a ˜10 km circular, complex, multi-ridged domal feature in the Unegt subbasin of the East Gobi Basin, southeastern Mongolia. As revealed by remote sensing and recent field reconnaissance, the central part of the Uneged Uul structure comprises a complex central peak of outward-radiating curved ridges, composed of stratigraphically uplifted greenschist-facies basement schists, surrounded by an annular moat. The most prominent feature of the structure is a central annular ridge ˜3 km in diameter composed of pebble-boulder conglomerates and gravels of the Upper Jurassic Sharilyn Formation, surrounded by three outer domal ridges composed of Lower Cretaceous conglomeratic sandstones and gypsum clays. Jurassic conglomerates forming the main part of the central annular ridge show effects of severe internal deformation. The original population of pebbles, cobbles and boulders appears moderately displaced and mostly broken but nowhere aligned along shear planes or foliated. Primary sedimentary features, such as cross-lamination or imbrication, have been obliterated. We explain this penetrative brecciation as a result of dissipative shearing caused by a strong and rapid singular event that in magnitude was beyond the range of the common crustal tectonics recorded elsewhere in this region. Disrupted and chaotically distributed conglomeratic sandstone beds in the central annular ridge dip in highly variable directions on a local scale but show an apparent SE-NW trend of bedding plane alignment. Further outside, the tilted and uplifted Upper Jurassic to Lower Cretaceous strata of the domal area are overlain by the flat-lying Upper Cretaceous, which stratigraphically constrains the timing of deformation at the Uneged Uul structure to most likely the Early Cretaceous. Endogenic formation models, such as magmatism and salt, gypsum, or mud diapirism, fail to explain the nature of the Uneged Uul structure. The Uneged Uul structure bears a set of

Isotopic and geochemical evidence of recharge sources and water quality in the Quaternary aquifer beneath Jinchang city, NW China

International Nuclear Information System (INIS)

Ma Jinzhu; Pan Feng; Chen Lihua; Edmunds, W. Mike; Ding Zhenyu; He Jianhua; Zhou Kunpeng; Huang Tianming

2010-01-01

Multiple isotopic and hydrogeochemical tracers were utilized to understand the recharge sources and geochemical evolution of groundwater in the Quaternary aquifer beneath Jinchang city and the adjacent Gobi desert area. The groundwater shows markedly depleted stable isotopic composition compared to modern rainfall. The signature of groundwaters from Jinchang and the northern Gobi desert area differ clearly from that of the alluvial fan in the south Yongchang basin and modern rainfall, and has lower or non-detectable 3 H activity, implying that the aquifer is likely maintained by palaeowater. This groundwater in the Gobi desert has a 14 C age older than 12 ka, indicating that the groundwater resources are non-renewable. The build-up of dissolved solids through evaporation is a major control on groundwater composition, and the dominant anion species change systematically from HCO 3 - , SO 4 2- to Cl - , but cations from weathering of albite, calcite, dolomite and gypsum also make a significant contribution. The scientific results have important implications for groundwater management in Jinchang city and as well as in the Shiyang River basin under China's West Development Strategy. It is recommended that the water allocation program of diverting water from the Dongda river to the Minqin basin be reconsidered.

Investigating Relationships between Reproduction, Immune Defenses, and Cortisol in Dall Sheep.

Science.gov (United States)

Downs, Cynthia J; Boan, Brianne V; Lohuis, Thomas D; Stewart, Kelley M

2018-01-01

Life-history theory is fundamental to understanding how animals allocate resources among survival, development, and reproduction, and among traits within these categories. Immediate trade-offs occur within a short span of time and, therefore, are more easily detected. Trade-offs, however, can also manifest across stages of the life cycle, a phenomenon known as carryover effects. We investigated trade-offs on both time scales in two populations of Dall sheep ( Ovis dalli dalli ) in Southcentral Alaska. Specifically, we (i) tested for glucocorticoid-mediated carryover effects from the breeding season on reproductive success and immune defenses during parturition and (ii) tested for trade-offs between immune defenses and reproduction within a season. We observed no relationship between cortisol during mating and pregnancy success; however, we found marginal support for a negative relationship between maternal cortisol and neonate birth weights. Low birth weights, resulting from high maternal cortisol, may result in low survival or low fecundity for the neonate later in life, which could result in overall population decline. We observed a negative relationship between pregnancy and bacterial killing ability, although we observed no relationship between pregnancy and haptoglobin. Study site affected bactericidal capacity and the inflammatory response, indicating the influence of external factors on immune responses, although we could not test hypotheses about the cause of those differences. This study helps advance our understanding of the plasticity and complexity of the immune system and provides insights into the how individual differences in physiology may mediate differences in fitness.

Holy Mackerel

OpenAIRE

Carrigy, Aoife

2014-01-01

Hi folks. My name is Aoife Carrigy and I’m a freelance food, wine and travel writer based in Dublin, Ireland. Having spent many happy years working front-of-house in restaurants – combined with dallies in book publishing, stints of teaching English and journalism, posts as restaurant reviewer for various free-sheets, and adventures in travel including a job as a cook on a 4WD tour of Australia’s north-west outback – I was lucky enough to work full-time as Deputy Editor of Ireland’s FOOD&WI...

Interspecific variation of ontogeny and skull shape among porpoises (Phocoenidae)

DEFF Research Database (Denmark)

Galatius-Jørgensen, Anders; Berta, Annalisa; Frandsen, Marie Michele Schou

2011-01-01

. dioptrica, for which large series were available, were further compared in terms of ontogeny of cranial shape by three-dimensional geometric morphometrics. Ph. dalli and P. dioptrica generally showed further development of cranial sutures than the other species. Postnatal skull shape development was similar...... was detected; in species with pelagic preference the position and orientation of the foramen magnum aligned the skull with the vertebral column; the rostrum showed less ventral inclination, and the facial region was larger and more concave in lateral aspect. J. Morphol., 2011. © 2010 Wiley-Liss, Inc....

Novelty versus environment: two viewpoints on the same phenomenon?

Czech Academy of Sciences Publication Activity Database

Janáč, Michal; Konečná, Markéta; Roche, Kevin Francis; Jurajda, Pavel

2016-01-01

Roč. 25, č. 4 (2016), s. 678-681 ISSN 0906-6691 Institutional support: RVO:68081766 Keywords : Neogobius melanostomus * Round goby * formalin Subject RIV: EG - Zoology Impact factor: 2.054, year: 2016

African Journal of Marine Science - Vol 33, No 1 (2011)

African Journals Online (AJOL)

... area between western and eastern Mediterranean basins (Siculo-Tunisian Strait) ... Cross-shelf observations of diet and diel feeding behaviour of the bearded goby ... WHH Sauer, W Potts, D Raberinary, J Anderson, MJ Sylvio Perrine.

Fish, Actinopterygii, Perciformes, Gobiidae, Amblyeleotris rubrimarginata Mohlmann and Randall, 2002: Range gap filled in northern Borneo

OpenAIRE

Townsend, D.

2010-01-01

The present work reports the shrimp goby Amblyeleotris rubrimarginata Mohlmann and Randall, 2002 in coralsand habitats off three different islands within the Tunku Abdul Rahman marine Park (TARP) off western Sabah in northernBorneo.

Investigating Relationships between Reproduction, Immune Defenses, and Cortisol in Dall Sheep

Directory of Open Access Journals (Sweden)

Cynthia J. Downs

2018-01-01

Full Text Available Life-history theory is fundamental to understanding how animals allocate resources among survival, development, and reproduction, and among traits within these categories. Immediate trade-offs occur within a short span of time and, therefore, are more easily detected. Trade-offs, however, can also manifest across stages of the life cycle, a phenomenon known as carryover effects. We investigated trade-offs on both time scales in two populations of Dall sheep (Ovis dalli dalli in Southcentral Alaska. Specifically, we (i tested for glucocorticoid-mediated carryover effects from the breeding season on reproductive success and immune defenses during parturition and (ii tested for trade-offs between immune defenses and reproduction within a season. We observed no relationship between cortisol during mating and pregnancy success; however, we found marginal support for a negative relationship between maternal cortisol and neonate birth weights. Low birth weights, resulting from high maternal cortisol, may result in low survival or low fecundity for the neonate later in life, which could result in overall population decline. We observed a negative relationship between pregnancy and bacterial killing ability, although we observed no relationship between pregnancy and haptoglobin. Study site affected bactericidal capacity and the inflammatory response, indicating the influence of external factors on immune responses, although we could not test hypotheses about the cause of those differences. This study helps advance our understanding of the plasticity and complexity of the immune system and provides insights into the how individual differences in physiology may mediate differences in fitness.

Non-linear density-dependent effects of an intertidal ecosystem engineer.

Science.gov (United States)

Harley, Christopher D G; O'Riley, Jaclyn L

2011-06-01

Ecosystem engineering is an important process in a variety of ecosystems. However, the relationship between engineer density and engineering impact remains poorly understood. We used experiments and a mathematical model to examine the role of engineer density in a rocky intertidal community in northern California. In this system, the whelk Nucella ostrina preys on barnacles (Balanus glandula and Chthamalus dalli), leaving empty barnacle tests as a resource (favorable microhabitat) for other species. Field experiments demonstrated that N. ostrina predation increased the availability of empty tests of both barnacle species, reduced the density of the competitively dominant B. glandula, and indirectly increased the density of the competitively inferior C. dalli. Empty barnacle tests altered microhabitat humidity, but not temperature, and presumably provided a refuge from wave action. The herbivorous snail Littorina plena was positively associated with empty test availability in both observational comparisons and experimental manipulations of empty test availability, and L. plena density was elevated in areas with foraging N. ostrina. To explore the effects of variation in N. ostrina predation, we constructed a demographic matrix model for barnacles in which we varied predation intensity. The model predicted that number of available empty tests increases with predation intensity to a point, but declines when predation pressure was strong enough to severely reduce adult barnacle densities. The modeled number of available empty tests therefore peaked at an intermediate level of N. ostrina predation. Non-linear relationships between engineer density and engineer impact may be a generally important attribute of systems in which engineers influence the population dynamics of the species that they manipulate.

Fish, Actinopterygii, Perciformes, Gobiidae, Amblyeleotris rubrimarginata Mohlmann and Randall, 2002: range gap filled in northern Borneo

OpenAIRE

Townsend, Ditch

2010-01-01

The present work reports the shrimp goby Amblyeleotris rubrimarginata Mohlmann and Randall, 2002 in coral sand habitats off three different islands within the Tunku Abdul Rahman marine Park (TARP) off western Sabah in northern Borneo.

An evaluation of the national measles vaccination campaign in the ...

African Journals Online (AJOL)

1991-04-20

Apr 20, 1991 ... sustained among Transkei-born children. Significant deter- ... a scale to assess the effect on specific urbanising communities. The planned ..... (GOBI-FFF) have demonstrated, this is not Utopian fantasy. On the contrary, a ...

Molecular taxonomy study of representatives of the genus Gobius inhabiting coastal waters of Black Sea region

Directory of Open Access Journals (Sweden)

Feriha Tserkova

2016-12-01

Full Text Available According to their origin the Black Sea gobies can be divided to Ponto-Caspian relicts and Mediterranean immigrants. The increase of species diversity in the Black Sea is a consequence of Mediterranean immigrants. The present study investigated the variability in Cytochrome b sequences isolated from two former Mediterranean immigrant species: Gobius niger and Zosterisessor ophiocephalus. The annotated at NCBI Cyt b sequences of the species were also used to extend the reach of the study. The analyses demonstrated that Black Sea inhabited by four haplotypes of G. niger. Four other haplotypes were found in sequences of Mediterranean black gobies. In the Black Sea haplotype, 6 is predominant and 83.5% of all G. niger representatives belong to it. Three other haplotypes (H_1; H_7 and H_8 were found to form isolated populations. The Tajima D-test indicated that in the Black Sea G. niger in a stage of expansion and significant evolutionary pressure according to data from Maximum Composite Likelihood model of Tamura-Nei, which can explain the accumulation of mutation and appearance of new haplotypes. Unlike G. niger, Z. ophiocephalus populations are shrinking according to Tajima D-test and only one haplotype is still surviving in isolated locations in the Black Sea. These data are in agreement with previous reports of other authors which alarmed that the grass goby is a critically endangered species close to extinction.

Crustal Structure and Mantle Transition Zone Thickness beneath the Central Mongolia from Teleseismic Receiver Functions

Science.gov (United States)

He, J.; Wu, Q.; Gao, M.; Munkhuu, U.; Demberel, S. G.

2013-12-01

The Mongolian Plateau (northern Asia) is situated between the Gobi-Altai range and the Siberian craton. In order to understand the crustal and mantle structure environmental characteristics, we use the teleseismic data recorded by 69 broadband stations located in the Central Mongolia(103.5°-111.5°E, 42°-50°N). The teleseismic events are selected from the global earthquakes between Aug. 2011 and Dec. 2013 with magnitude >5.5and the epicentral distance range from 30° to 95° to the center of the network. Lateral variations of the crustal thicknesses H and Vp/Vs ratios are obtained by using receiver function method. The crust thins gradually from northwest to southeast in the studying field. We found that the thinnest crust is ~37.5km in the southeast which is Gobi. The distribution of Vp/Vs ratios are between 1.68 and 1.84, which shows the heterogeneity. There are three high-anomaly areas: the Gobi range which is the Later Paleozoic Orogeny; the Khentei Mountains which is in the Jurassic-Cretaceous Reactive Continental Margin; the northwest area which is granite. Our research not only reveals the powerful evident of the crustal formation and evolution mechanism, but also provides some constraints on the mechanism of uplift of the Mongolian Plateau.This study was supported by the international cooperation project of the Ministry of Science and Technology of China (2011DFB20120).

Hypoxia increases the risk of egg predation in a nest-guarding fish

DEFF Research Database (Denmark)

Olsson, Karin; Kvarnemo, Charlotta; Andrén, Maria Norevik

2016-01-01

For fish with parental care, a nest should meet both the oxygenation needs of the eggs and help protect them against predators. While a small nest opening facilitates the latter, it impedes the former and vice versa. We investigated how the presence of potential egg predators in the form of shore...... in high oxygen reduced fanning, males in low oxygen did not. Filial cannibalism was unaffected by treatment. Sand gobies thus prioritize egg ventilation over the protection afforded by small nest openings under hypoxia and adopt defensive behaviour to avert predator attention, even though this does...... crabs Carcinus maenas affects nest building, egg fanning, defensive displays and filial cannibalism of egg-guarding male sand gobies Pomatoschistus minutus under two levels of dissolved oxygen. In the high oxygen treatment, males retained their nest opening size in the presence of crabs, while males...

NATIVE AND INTRODUCED LARVAL FISHES IN SUISAN MARSH, CALIFORNIA,: THE EFFECTS OF FRESHWATER FLOW

Science.gov (United States)

We sampled ichthyoplankton weekly in Suisun Marsh in the San Francisco Estuary from February to June each year from 1994 to 1999. We collected approximately 227,900 fish, predominantly shimofuri goby Tridentiger bifasciatus (60%) and prickly sculpin Cottus asper (33%). Principal ...

The effect of meal size on gastric evacuation in whiting

DEFF Research Database (Denmark)

Andersen, Niels Gerner

1998-01-01

Gastric evacuation experiments were performed on whiting Merlangius merlangus fed discrete meals of different sizes. Herring Clupea harengus, sandeel Ammodytes tobianus, common goby Pomatoschistus microps, and brown shrimp Crangon crangon were tested as prey. A simple power model to describe...

Invazní druhy ryb - co o nich víme? Případ hlaváče říčního

Czech Academy of Sciences Publication Activity Database

Konečná, Markéta

2013-01-01

Roč. 2013, 05 (2013), s. 10-12 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : native monkey goby Subject RIV: EG - Zoology https://cs.publero.com/title/vertebratus-cz/5-2013

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Genetics; Volume 96; Online resources. Population genetic diversity of marble goby (Oxyeleotris marmoratus)inferred from mitochondrial DNA and microsatellite analysis. CHENG ZHAO XIAOPING ZHU YICHUN GU QINTAO WANG ZECHENG LI SHAOWU YIN. ONLINE RESOURCES Volume 96 ...

Genome-wide set of SNPs reveals evidence for two glacial refugia and admixture from postglacial recolonization in an alpine ungulate.

Science.gov (United States)

Sim, Zijian; Hall, Jocelyn C; Jex, Bill; Hegel, Troy M; Coltman, David W

2016-08-01

Past glaciation events have played a major role in shaping the genetic diversity and distribution of wild sheep in North America. The advancement of glaciers can isolate populations in ice-free refugia, where they can survive until the recession of ice sheets. The major Beringian refugium is thought to have held thinhorn sheep (Ovis dalli) populations during times of glacial advance. While isolation in the major refugium can account for much of the genetic and morphological diversity seen in extant thinhorn sheep populations, mounting evidence suggests the persistence of populations in smaller minor refugia. We investigated the refugial origins of thinhorn sheep using ~10 000 SNPs obtained via a cross-species application of the domestic sheep ovine HD BeadChip to genotype 52 thinhorn sheep and five bighorn sheep (O. canadensis) samples. Phylogenetic inference revealed a distinct lineage of thinhorn sheep inhabiting British Columbia, which is consistent with the survival of a group of thinhorn sheep in a minor refugium separate from the Beringian refugium. Isolation in separate glacial refugia probably mediated the evolution of the two thinhorn sheep subspecies, the white Dall's sheep (O. d. dalli), which persisted in Beringia, and the dark Stone's sheep (O. d. stonei), which utilized the minor refugium. We also found the first genetic evidence for admixture between sheep from different glacial refugia in south-central Yukon as a consequence of post glacial expansion and recolonization. These results show that glaciation events can have a major role in the evolution of species inhabiting previously glaciated habitats and the need to look beyond established refugia when examining the evolutionary history of such species. © 2016 John Wiley & Sons Ltd.

Analysis of a solar water thermosyphon system; Analise do aquecimento solar de agua por sistema a termosifao

Energy Technology Data Exchange (ETDEWEB)

Cardenas, Abner Barzola

1992-07-01

A design methodology and to perform the simulation of flat plate solar collectors coupled with a water storage tank and operating by natural convection circulation is presented. For a given site the incident solar radiation on a tilted and previously oriented surface is determined from solar astronomy and the dally average of the monthly data of the horizontal total solar radiation. Huancayo situated in Peru (at 12.05 deg S, long. 76.18 deg W, altitude 3,312 m), is chosen as the site to be installed the solar water system, as a mean to improve the peasant's standard of life. An optimum tilt angle for a north oriented collector surface is obtained in order to have a maximum solar capture during the water. The theoretical methodology use here is based upon the ONG's paper (1976), and in attrition is considered the hot water drainage due to the dally consumption. For the sake of comparison, the calculated flowrate values are confronted with the experimental data obtained by FERNANDEZ, for a same site location (Rio de Janeiro) and are used identical dimensions for the water thermosyphon heater. Finally, the economic feasibility of the solar water system is demonstrated when it is compared with the usual immersion electric resistance boiler. For the Peruvian conditions the more adequate solar water system for a rural or domestic usage is a 1.4 m{sup 2} area solar collector (6 parallel, 15,875 mm copper tubes), 100 l capacity for the water storage tank, 33.5 mm for the connecting tubes, being of 300 mm. The height between the collector top and the bottom of the tank. (author)

SNP discovery in candidate adaptive genes using exon capture in a free-ranging alpine ungulate

Science.gov (United States)

Roffler, Gretchen H.; Amish, Stephen J.; Smith, Seth; Cosart, Ted F.; Kardos, Marty; Schwartz, Michael K.; Luikart, Gordon

2016-01-01

Identification of genes underlying genomic signatures of natural selection is key to understanding adaptation to local conditions. We used targeted resequencing to identify SNP markers in 5321 candidate adaptive genes associated with known immunological, metabolic and growth functions in ovids and other ungulates. We selectively targeted 8161 exons in protein-coding and nearby 5′ and 3′ untranslated regions of chosen candidate genes. Targeted sequences were taken from bighorn sheep (Ovis canadensis) exon capture data and directly from the domestic sheep genome (Ovis aries v. 3; oviAri3). The bighorn sheep sequences used in the Dall's sheep (Ovis dalli dalli) exon capture aligned to 2350 genes on the oviAri3 genome with an average of 2 exons each. We developed a microfluidic qPCR-based SNP chip to genotype 476 Dall's sheep from locations across their range and test for patterns of selection. Using multiple corroborating approaches (lositan and bayescan), we detected 28 SNP loci potentially under selection. We additionally identified candidate loci significantly associated with latitude, longitude, precipitation and temperature, suggesting local environmental adaptation. The three methods demonstrated consistent support for natural selection on nine genes with immune and disease-regulating functions (e.g. Ovar-DRA, APC, BATF2, MAGEB18), cell regulation signalling pathways (e.g. KRIT1, PI3K, ORRC3), and respiratory health (CYSLTR1). Characterizing adaptive allele distributions from novel genetic techniques will facilitate investigation of the influence of environmental variation on local adaptation of a northern alpine ungulate throughout its range. This research demonstrated the utility of exon capture for gene-targeted SNP discovery and subsequent SNP chip genotyping using low-quality samples in a nonmodel species.

Lack of sex-biased dispersal promotes fine-scale genetic structure in alpine ungulates

Science.gov (United States)

Roffler, Gretchen H.; Talbot, Sandra L.; Luikart, Gordon; Sage, George K.; Pilgrim, Kristy L.; Adams, Layne G.; Schwartz, Michael K.

2014-01-01

Identifying patterns of fine-scale genetic structure in natural populations can advance understanding of critical ecological processes such as dispersal and gene flow across heterogeneous landscapes. Alpine ungulates generally exhibit high levels of genetic structure due to female philopatry and patchy configuration of mountain habitats. We assessed the spatial scale of genetic structure and the amount of gene flow in 301 Dall’s sheep (Ovis dalli dalli) at the landscape level using 15 nuclear microsatellites and 473 base pairs of the mitochondrial (mtDNA) control region. Dall’s sheep exhibited significant genetic structure within contiguous mountain ranges, but mtDNA structure occurred at a broader geographic scale than nuclear DNA within the study area, and mtDNA structure for other North American mountain sheep populations. No evidence of male-mediated gene flow or greater philopatry of females was observed; there was little difference between markers with different modes of inheritance (pairwise nuclear DNA F ST = 0.004–0.325; mtDNA F ST = 0.009–0.544), and males were no more likely than females to be recent immigrants. Historical patterns based on mtDNA indicate separate northern and southern lineages and a pattern of expansion following regional glacial retreat. Boundaries of genetic clusters aligned geographically with prominent mountain ranges, icefields, and major river valleys based on Bayesian and hierarchical modeling of microsatellite and mtDNA data. Our results suggest that fine-scale genetic structure in Dall’s sheep is influenced by limited dispersal, and structure may be weaker in populations occurring near ancestral levels of density and distribution in continuous habitats compared to other alpine ungulates that have experienced declines and marked habitat fragmentation.

Analysis of a solar water thermosyphon system; Analise do aquecimento solar de agua por sistema a termosifao

Energy Technology Data Exchange (ETDEWEB)

Cardenas, Abner Barzola

1992-07-01

A design methodology and to perform the simulation of flat plate solar collectors coupled with a water storage tank and operating by natural convection circulation is presented. For a given site the incident solar radiation on a tilted and previously oriented surface is determined from solar astronomy and the dally average of the monthly data of the horizontal total solar radiation. Huancayo situated in Peru (at 12.05 deg S, long. 76.18 deg W, altitude 3,312 m), is chosen as the site to be installed the solar water system, as a mean to improve the peasant's standard of life. An optimum tilt angle for a north oriented collector surface is obtained in order to have a maximum solar capture during the water. The theoretical methodology use here is based upon the ONG's paper (1976), and in attrition is considered the hot water drainage due to the dally consumption. For the sake of comparison, the calculated flowrate values are confronted with the experimental data obtained by FERNANDEZ, for a same site location (Rio de Janeiro) and are used identical dimensions for the water thermosyphon heater. Finally, the economic feasibility of the solar water system is demonstrated when it is compared with the usual immersion electric resistance boiler. For the Peruvian conditions the more adequate solar water system for a rural or domestic usage is a 1.4 m{sup 2} area solar collector (6 parallel, 15,875 mm copper tubes), 100 l capacity for the water storage tank, 33.5 mm for the connecting tubes, being of 300 mm. The height between the collector top and the bottom of the tank. (author)

Food conditions of the sand goby

NARCIS (Netherlands)

Freitas, V.; Lika, K.; Witte, J.IJ.; van der Veer, H.W.

2011-01-01

Several epibenthic species aggregate in large numbers in shallow waters during summer, feeding on the available benthic meio- and macrofauna. Whether this concentration leads to periods of food limitation affecting habitat quality for some of these species is not clear at present. In this study we

Nematode eel parasite found inside acanthocephalan cysts--a "Trojan horse" strategy?

Science.gov (United States)

Emde, Sebastian; Rueckert, Sonja; Kochmann, Judith; Knopf, Klaus; Sures, Bernd; Klimpel, Sven

2014-11-18

The invasive eel parasite Anguillicoloides crassus (syn. Anguillicola crassus) is considered one of the major causes for the decline of the European eel (Anguilla anguilla) panmictic population. It impairs the swim bladder function and reduces swimming performance of its host. The life cycle of this parasite involves different intermediate and paratenic hosts. Despite an efficient immune system of the paratenic fish hosts acting against infections with A. crassus, levels of parasitized eels remain high in European river systems. Recently, the round goby Neogobius melanostomus (Gobiidae) has become dominant in many rivers in Europe and is still spreading at a rapid pace. This highly invasive species might potentially act as an important, so far neglected paratenic fish host for A. crassus. Based on own observations and earlier single sightings of A. crassus in N. melanostomus, 60 fresh individuals of N. melanostomus were caught in the Rhine River and examined to assess the infection levels with metazoan parasites, especially A. crassus. Glycerin preparations were used for parasite identification. The parasite most frequently found in N. melanostomus was the acanthocephalan Pomphorhynchus sp. (subadult stage) which occurred mainly encysted in the mesenteries and liver. Every third gobiid (P = 31.7%) was infected by A. crassus larvae (L3) which exclusively occurred inside the acanthocephalan cysts. No intact or degenerated larvae of A. crassus were detected elsewhere in the goby, neither in the body cavity and mesenteries nor in other organs. Affected cysts contained the acanthocephalan larvae and 1-12 (mI =3) living A. crassus larvae. Additionally, encysted larvae of the nematode Raphidascaris acus were detected in the gobies, but only in the body cavity and not inside the acanthocephalan cysts. Based on our observations, we suggest that A. crassus might actively bypass the immune response of N. melanostomus by invading the cysts of acanthocephalan parasites of the

Deep Learning Methods for Quantifying Invasive Benthic Species in the Great Lakes

Science.gov (United States)

Billings, G.; Skinner, K.; Johnson-Roberson, M.

2017-12-01

In recent decades, invasive species such as the round goby and dreissenid mussels have greatly impacted the Great Lakes ecosystem. It is critical to monitor these species, model their distribution, and quantify the impacts on the native fisheries and surrounding ecosystem in order to develop an effective management response. However, data collection in underwater environments is challenging and expensive. Furthermore, the round goby is typically found in rocky habitats, which are inaccessible to standard survey techniques such as bottom trawling. In this work we propose a robotic system for visual data collection to automatically detect and quantify invasive round gobies and mussels in the Great Lakes. Robotic platforms equipped with cameras can perform efficient, cost-effective, low-bias benthic surveys. This data collection can be further optimized through automatic detection and annotation of the target species. Deep learning methods have shown success in image recognition tasks. However, these methods often rely on a labelled training dataset, with up to millions of labelled images. Hand labeling large numbers of images is expensive and often impracticable. Furthermore, data collected in the field may be sparse when only considering images that contain the objects of interest. It is easier to collect dense, clean data in controlled lab settings, but this data is not a realistic representation of real field environments. In this work, we propose a deep learning approach to generate a large set of labelled training data realistic of underwater environments in the field. To generate these images, first we draw random sample images of individual fish and mussels from a library of images captured in a controlled lab environment. Next, these randomly drawn samples will be automatically merged into natural background images. Finally, we will use a generative adversarial network (GAN) that incorporates constraints of the physical model of underwater light propagation

The community structure of over-wintering larval and small juvenile fish in a large estuary

DEFF Research Database (Denmark)

Munk, Peter; Cardinale, Massimiliano; Casini, Michele

2014-01-01

and abundances are described, and linkages between ichthyoplankton abundances and corresponding hydrographical information are analysed by GAM methods. Communities were dominated by herring, gobies, butterfish, sprat, pipefishes, lemon sole and European eel (i.e. glass eel), and all the sampled species showed...

Evolution of microhabitat association and morphology in a diverse group of cryptobenthic coral reef fishes (Teleostei: Gobiidae: Eviota)

KAUST Repository

Tornabene, Luke; Ahmadia, Gabby N.; Berumen, Michael L.; Smith, David J.; Jompa, Jamaluddì n; Pezold, Frank L.

2013-01-01

Gobies (Teleostei: Gobiidae) are an extremely diverse and widely distributed group and are the second most species rich family of vertebrates. Ecological drivers are key to the evolutionary success of the Gobiidae. However, ecological and phylogenetic data are lacking for many diverse genera of gobies. Our study investigated the evolution of microhabitat association across the phylogeny of 18 species of dwarfgobies (genus Eviota), an abundant and diverse group of coral reef fishes. In addition, we also explore the evolution of pectoral fin-ray branching and sensory head pores to determine the relationship between morphological evolution and microhabitat shifts. Our results demonstrate that Eviota species switched multiple times from a facultative hard-coral association to inhabiting rubble or mixed sand/rubble habitat. We found no obvious relationship between microhabitat shifts and changes in pectoral fin-ray branching or reduction in sensory pores, with the latter character being highly homoplasious throughout the genus. The relative flexibility in coral-association in Eviota combined with the ability to move into non-coral habitats suggests a genetic capacity for ecological release in contrast to the strict obligate coral-dwelling relationship commonly observed in closely related coral gobies, thus promoting co-existence through fine scale niche partitioning. The variation in microhabitat association may facilitate opportunistic ecological speciation, and species persistence in the face of environmental change. This increased speciation opportunity, in concert with a high resilience to extinction, may explain the exceptionally high diversity seen in Eviota compared to related genera in the family. © 2012 Elsevier Inc.

Performance and scaling of a novel locomotor structure: adhesive capacity of climbing gobiid fishes.

Science.gov (United States)

Maie, Takashi; Schoenfuss, Heiko L; Blob, Richard W

2012-11-15

Many species of gobiid fishes adhere to surfaces using a sucker formed from fusion of the pelvic fins. Juveniles of many amphidromous species use this pelvic sucker to scale waterfalls during migrations to upstream habitats after an oceanic larval phase. However, adults may still use suckers to re-scale waterfalls if displaced. If attachment force is proportional to sucker area and if growth of the sucker is isometric, then increases in the forces that climbing fish must resist might outpace adhesive capacity, causing climbing performance to decline through ontogeny. To test for such trends, we measured pressure differentials and adhesive suction forces generated by the pelvic sucker across wide size ranges in six goby species, including climbing and non-climbing taxa. Suction was achieved via two distinct growth strategies: (1) small suckers with isometric (or negatively allometric) scaling among climbing gobies and (2) large suckers with positively allometric growth in non-climbing gobies. Species using the first strategy show a high baseline of adhesive capacity that may aid climbing performance throughout ontogeny, with pressure differentials and suction forces much greater than expected if adhesion were a passive function of sucker area. In contrast, large suckers possessed by non-climbing species may help compensate for reduced pressure differentials, thereby producing suction sufficient to support body weight. Climbing Sicyopterus species also use oral suckers during climbing waterfalls, and these exhibited scaling patterns similar to those for pelvic suckers. However, oral suction force was considerably lower than that for pelvic suckers, reducing the ability for these fish to attach to substrates by the oral sucker alone.

Gyrodactylus proterorhini in its non-native range: distribution and ability to host-switch in freshwaters

Czech Academy of Sciences Publication Activity Database

Ondračková, Markéta

2016-01-01

Roč. 115, č. 8 (2016), s. 3153-3162 ISSN 0932-0113 R&D Projects: GA ČR(CZ) GAP505/12/2569 Institutional support: RVO:68081766 Keywords : Gobies * Gyrodactylidae * Introduction * Ponto-Caspian * Range expansion Subject RIV: EH - Ecology, Behaviour Impact factor: 2.329, year: 2016

76 FR 64995 - Endangered and Threatened Wildlife and Plants; Designation of Revised Critical Habitat for the...

Science.gov (United States)

2011-10-19

... do not possess stream channels or tributaries that provide a considerable amount of water throughout... sedimentation of coastal lagoons and riparian habitats, removal of vegetative cover, increased ambient water... channels. As a result, several of the locations occupied by tidewater goby do not contain natural sandbars...

Snowscape Ecology: Linking Snow Properties to Wildlife Movements and Demography

Science.gov (United States)

Prugh, L.; Verbyla, D.; van de Kerk, M.; Mahoney, P.; Sivy, K. J.; Liston, G. E.; Nolin, A. W.

2017-12-01

Snow enshrouds up to one third of the global land mass annually and exerts a major influence on animals that reside in these "snowscapes," (landscapes covered in snow). Dynamic snowscapes may have especially strong effects in arctic and boreal regions where dry snow persists for much of the year. Changes in temperature and hydrology are transforming northern regions, with profound implications for wildlife that are not well understood. We report initial findings from a NASA ABoVE project examining effects of snow properties on Dall sheep (Ovis dalli dalli). We used the MODSCAG snow fraction product to map spring snowline elevations and snow-off dates from 2000-2015 throughout the global range of Dall sheep in Alaska and northwestern Canada. We found a negative effect of spring snow cover on Dall sheep recruitment that increased with latitude. Using meteorological data and a daily freeze/thaw status product derived from passive microwave remote sensing from 1983-2012, we found that sheep survival rates increased in years with higher temperatures, less winter precipitation, fewer spring freeze-thaw events, and more winter freeze-thaw events. To examine the effects of snow depth and density on sheep movements, we used location data from GPS-collared sheep and a snowpack evolution model (SnowModel). We found that sheep selected for shallow, fluffy snow at high elevations, but they selected for denser snow as depth increased. Our field measurements identified a critical snow density threshold of 329 (± 18 SE) kg/m3 to support the weight of Dall sheep. Thus, sheep may require areas of shallow, fluffy snow for foraging, while relying on hard-packed snow for winter travel. These findings highlight the importance of multiple snowscape properties on wildlife movements and demography. The integrated study of snow properties and ecological processes, which we call snowscape ecology, will greatly improve global change forecasting.

Is the osmorespiratory compromise limiting invasive species?

DEFF Research Database (Denmark)

Ferreira, Patricia Gomes; Flavio, Hugo; Hacking, Harry

The round goby (Neogobius melanostomus) is a benthic fish native to the brackish waters of the Black and Caspian Seas; however, it has invaded several brackish and freshwater areas in North America and northern Europe. Notably, there are no records of N. melanostomus in high salinity marine habit...

76 FR 3069 - Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To Delist or...

Science.gov (United States)

2011-01-19

... feeding, breeding, and sheltering; (b) Genetics and taxonomy; (c) Historical and current range, including..., and the tidewater goby. Petition History On May 18, 2010, we received a petition dated May 13, 2010... be deferred until taxonomic research referred to in the Genetics section of the 2007 5-year review...

Tubenose goby Proterorhinus marmoratus (Pallas, 1814) has joined three other Ponto-Caspian gobies in the Vistula River (Poland)

Czech Academy of Sciences Publication Activity Database

Grabowska, J.; Pietraszewski, D.; Ondračková, Markéta

2008-01-01

Roč. 3, č. 2 (2008), s. 261-265 ISSN 1818-5487 Institutional research plan: CEZ:AV0Z60930519 Keywords : gobiids * invasive species * invasion corridor Subject RIV: EH - Ecology, Behaviour http://www.aquaticinvasions.ru/2008/AI_2008_3_2_Grabowska_etal.pdf

Benthic prey fish assessment, Lake Ontario 2013

Science.gov (United States)

Weidel, Brian C.; Walsh, Maureen; Connerton, Michael J.

2014-01-01

The 2013 benthic fish assessment was delayed and shortened as a result of the U.S. Government shutdown, however the assessment collected 51 of the 62 planned bottom trawls. Over the past 34 years, Slimy Sculpin abundance in Lake Ontario has fluctuated, but ultimately decreased by two orders of magnitude, with a substantial decline occurring in the past 10 years. The 2013 Slimy Sculpin mean bottom trawl catch density (0.001 ind.·m-2, s.d.= 0.0017, n = 52) and mean biomass density (0.015 g·m-2 , s.d.= 0.038, n = 52) were the lowest recorded in the 27 years of sampling using the original bottom trawl design. From 2011-2013, the Slimy Sculpin density and biomass density has decreased by approximately 50% each year. Spring bottom trawl catches illustrate Slimy Sculpin and Round Goby Neogobius melanostoma winter habitat overlaps for as much as 7 months out of a year, providing opportunities for competition and predation. Invasive species, salmonid piscivory, and declines in native benthic invertebrates are likely all important drivers of Slimy Sculpin population dynamics in Lake Ontario. Deepwater Sculpin Myoxocephalus thompsonii, considered rare or absent from Lake Ontario for 30 years, have generally increased over the past eight years. For the first time since they were caught in this assessment, Deepwater Sculpin density and biomass density estimates declined from the previous year. The 2013 abundance and density estimates for trawls covering the standard depths from 60m to 150m was 0.0001 fish per square meter and 0.0028 grams per square meter. In 2013, very few small (recruitment. Nonnative Round Gobies were first detected in the USGS/NYSDEC Lake Ontario spring Alewife assessment in 2002. Since that assessment, observations indicate their population has expanded and they are now found along the entire south shore of Lake Ontario, with the highest densities in U.S. waters just east of the Niagara River confluence. In the 2013 spring-based assessment, both the

The Modulation of Fibrosis In Scleroderma by 3-Deoxyglucosone

Science.gov (United States)

2011-06-01

24 h . . RNA was extracted and quantitative real-time PCR was performed for the GObi AI transcript. Transcript levels were normalized to !3-actin. AJI ... Red X denotes the negative effect of 3DG-collagen on that pathway. 54 55 Reference List (1) Kessler D, Dethlefsen S, Haase I, Plomann M

Final Supplemental Environmental Assessment: Falcon I Launch Vehicle Program from SLC-4W Vandenberg Air Force Base, California

Science.gov (United States)

2005-09-06

affected surface water, 3) adversely affected groundwater quantity or quality, or 4) caused a need that exceeded the existing potable supply or...goby is from Tillas Slough (mouth of the Smith River) in Del Norte County, south to Colonel Louis D. Van Mullem, Jr. (1-8-96-F/C-29) 5 Agua Hedionda

Long-term monitoring of native bullhead and invasive gobiids in the Danubian rip-rap zone

Czech Academy of Sciences Publication Activity Database

Janáč, Michal; Roche, Kevin Francis; Šlapanský, Luděk; Polačik, Matej; Jurajda, Pavel

2018-01-01

Roč. 807, č. 1 (2018), s. 263-275 ISSN 0018-8158 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : Competition * Fish population structure * Invasive species impact * Ponto–Caspian gobies * River bank stabilisation Subject RIV: EG - Zoology Impact factor: 2.056, year: 2016

The latest geodynamics in Asia: Synthesis of data on volcanic evolution, lithosphere motion, and mantle velocities in the Baikal-Mongolian region

Directory of Open Access Journals (Sweden)

Sergei Rasskazov

2017-07-01

Full Text Available From a synthesis of data on volcanic evolution, movement of the lithosphere, and mantle velocities in the Baikal-Mongolian region, we propose a comprehensive model for deep dynamics of Asia that assumes an important role of the Gobi, Baikal, and North Transbaikal transition-layer melting anomalies. This layer was distorted by lower-mantle fluxes at the beginning of the latest geodynamic stage (i.e. in the early late Cretaceous due to avalanches of slab material that were stagnated beneath the closed fragments of the Solonker, Ural-Mongolian paleoceans and Mongol-Okhotsk Gulf of Paleo-Pacific. At the latest geodynamic stage, Asia was involved in east–southeast movement, and the Pacific plate moved in the opposite direction with subduction under Asia. The weakened upper mantle region of the Gobi melting anomaly provided a counterflow connected with rollback in the Japan Sea area. These dynamics resulted in the formation of the Honshu-Korea flexure of the Pacific slab. A similar weakened upper mantle region of the North Transbaikal melting anomaly was associated with the formation of the Hokkaido-Amur flexure of the Pacific slab, formed due to progressive pull-down of the slab material into the transition layer in the direction of the Pacific plate and Asia convergence. The early–middle Miocene structural reorganization of the mantle processes in Asia resulted in the development of upper mantle low-velocity domains associated with the development of rifts and orogens. We propose that extension at the Baikal Rift was caused by deviator flowing mantle material, initiated under the moving lithosphere in the Baikal melting anomaly. Contraction at the Hangay orogen was created by facilitation of the tectonic stress transfer from the Indo-Asian interaction zone due to the low-viscosity mantle in the Gobi melting anomaly.

Musculoskeletal determinants of pelvic sucker function in Hawaiian stream gobiid fishes: interspecific comparisons and allometric scaling.

Science.gov (United States)

Maie, Takashi; Schoenfuss, Heiko L; Blob, Richard W

2013-07-01

Gobiid fishes possess a distinctive ventral sucker, formed from fusion of the pelvic fins. This sucker is used to adhere to a wide range of substrates including, in some species, the vertical cliffs of waterfalls that are climbed during upstream migrations. Previous studies of waterfall-climbing goby species have found that pressure differentials and adhesive forces generated by the sucker increase with positive allometry as fish grow in size, despite isometry or negative allometry of sucker area. To produce such scaling patterns for pressure differential and adhesive force, waterfall-climbing gobies might exhibit allometry for other muscular or skeletal components of the pelvic sucker that contribute to its adhesive function. In this study, we used anatomical dissections and modeling to evaluate the potential for allometric growth in the cross-sectional area, effective mechanical advantage (EMA), and force generating capacity of major protractor and retractor muscles of the pelvic sucker (m. protractor ischii and m. retractor ischii) that help to expand the sealed volume of the sucker to produce pressure differentials and adhesive force. We compared patterns for three Hawaiian gobiid species: a nonclimber (Stenogobius hawaiiensis), an ontogenetically limited climber (Awaous guamensis), and a proficient climber (Sicyopterus stimpsoni). Scaling patterns were relatively similar for all three species, typically exhibiting isometric or negatively allometric scaling for the muscles and lever systems examined. Although these scaling patterns do not help to explain the positive allometry of pressure differentials and adhesive force as climbing gobies grow, the best climber among the species we compared, S. stimpsoni, does exhibit the highest calculated estimates of EMA, muscular input force, and output force for pelvic sucker retraction at any body size, potentially facilitating its adhesive ability. Copyright © 2013 Wiley Periodicals, Inc.

Climate Change | Page 75 | IDRC - International Development ...

International Development Research Centre (IDRC) Digital Library (Canada)

Read more about Sri Lanka better prepared for future tsunamis. Language English. Gabin Koto N'Gobi's research focuses on water. But it was the lack of water in the semi-arid northern region of his home country, Benin, which really motivated him. Read more about Every drop counts: Interview with awardee Gabin Koto N' ...

Community shelter use in response to two benthic decapod predators in the Long Island Sound.

Science.gov (United States)

Hudson, David M; Reagan, Dugan; Crivello, Joseph F

2016-01-01

To investigate community shelter effects of two invasive decapod species, Hemigrapsus sanguineus and Carcinus maenas, in the Long Island Sound (LIS), we deployed artificial shelters in the intertidal and immediate subtidal zones. These consisted of five groups during the summer: a control, a resident H. sanguineus male or female group, and a resident C. maenas male or female group. We quantified utilization of the shelters at 24 h by counting crabs and fish present. We found significant avoidance of H. sanguineus in the field by benthic hermit crabs (Pagurus spp.) and significant avoidance of C. maenas by the seaboard goby (Gobiosoma ginsburgi). The grubby (Myoxocephalus aenaeus) avoided neither treatment, probably since it tends to be a predator of invertebrates. H. sanguineus avoided C. maenas treatments, whereas C. maenas did not avoid any treatment. Seasonal deployments in the subtidal indicated cohabitation of a number of benthic species in the LIS, with peak shelter use corresponding with increased predation and likely reproductive activity in spring and summer for green crabs (C. maenas), hermit crabs (Pagurus spp.), seaboard gobies (G. ginsburgi), and grubbies (Myoxocephalus aenaeus).

Drosophila VAMP7 regulates Wingless intracellular trafficking.

Science.gov (United States)

Gao, Han; He, Fang; Lin, Xinhua; Wu, Yihui

2017-01-01

Drosophila Wingless (Wg) is a morphogen that determines cell fate during development. Previous studies have shown that endocytic pathways regulate Wg trafficking and signaling. Here, we showed that loss of vamp7, a gene required for vesicle fusion, dramatically increased Wg levels and decreased Wg signaling. Interestingly, we found that levels of Dally-like (Dlp), a glypican that can interact with Wg to suppress Wg signaling at the dorsoventral boundary of the Drosophila wing, were also increased in vamp7 mutant cells. Moreover, Wg puncta in Rab4-dependent recycling endosomes were Dlp positive. We hypothesize that VAMP7 is required for Wg intracellular trafficking and the accumulation of Wg in Rab4-dependent recycling endosomes might affect Wg signaling.

Biodiversity and Biogeography of Chthamalid Barnacles from the North-Eastern Pacific (Crustacea Cirripedia.

Directory of Open Access Journals (Sweden)

Benny K K Chan

Full Text Available The biogeography and ecology of the species of Chthamalus present on the west coast of America are described, using data from 51 localities from Alaska to Panama, together with their zonation on the shore with respect to that of other barnacles. The species present were C. dalli, Pilsbry 1916, C. fissus, Darwin, 1854, C. anisopoma Pilsbry 1916 and four species in the C. panamensis complex. The latter are C. panamensis Pilsbry, 1916, C. hedgecocki, Pitombo & Burton, 2007, C. alani nom. nov. (formerly C. southwardorum Pitombo & Burton, 2007 and C. newmani sp. nov.. These four species were initially separated by enzyme electrophoresis. They could only be partially separated by DNA bar coding but may be separated using morphological characters.

77 FR 43222 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Tidewater...

Science.gov (United States)

2012-07-24

... proposed in critical habitat unit MAR-5 Bolinas Lagoon and SLO-12 Oso Flaco Lake, as well as additional surveying for tidewater goby in Oso Flaco Lake. As we stated earlier, we are soliciting data and comments... Lagoon, SLO-1 Arroyo de la Cruz, SLO-12 Oso Flaco Lake, LA-1 Arroyo Sequit, and LA-2 Zuma Canyon. These...

Asthenospheric counterflows beneath the moving lithosphere of Central and East Asia in the past 90 Ma: volcanic and tomographic evidence

Science.gov (United States)

Rasskazov, Sergei; Chuvashova, Irina; Kozhevnikov, Vladimir

2015-04-01

Asthenospheric counterflows, accompanied motions of the lithosphere in Central and East Asia, are defined on basis of spatial-temporal activity of mantle sources [Rasskazov et al., 2012; Rasskazov, Chuvashova, 2013; Chuvashova, Rasskazov, 2014] and the tomographic model of the Rayleigh wave group velocities [Kozhevnikov et al., 2014]. The opposite fluxes are defined relative to centers of convective instability (low-velocity anomalies), expressed by thinning of the mantle transition layer under Southwestern Gobi (44 °N, 95 °E) and Northern Baikal (52 °N, 108 °E). Cretaceous-Paleogene volcanic fields in Southern Gobi are shifted eastwards relative to the former anomaly over 600 km with the opposite sub-lithospheric flux at depths of 150-300 km. Likewise, the Late Tertiary Vitim volcanic field is shifted relative to the latter anomaly over 100-200 km. We suggest that the Gobi and Baikal asthenospheric counterflows contributed to the rollback mechanism of downgoing slab material from the Pacific under the eastern margin of Asia in the Cretaceous-Paleogene and Early-Middle Miocene. The east-west Gobi reverse flux, caused by differential block motions in front of the Indo-Asian convergence, resulted in the oblique Honshu-Korean flexure of the Pacific slab that propagated beneath the continental margin, while the Japan Sea was quickly opening at about 15 Ma. The Baikal N60°W reverse flux, originated due to oncoming traffic between Eurasia and the Pacific plate, entailed the formation of the Baikal Rift Zone and direct Hokkaido Amur slab flexure [Rasskazov et al., 2004]. The study is supported by the Russian Foundation for Basic Research (Grant 14-05-31328). References Chuvashova I.S., Rasskazov S.V. Magmatic sources in the mantle of the evolving Earth. Irkutsk: Publishing House of the Irkutsk State University, 2014. 310 p. (in Russian) Kozhevnikov V.M., Seredkina A.I., Solovei O.A. 3D mantle structure of Central Asia from Rayleigh wave group velocity dispersion

Great Lakes prey fish populations: a cross-basin overview of status and trends based on bottom trawl surveys, 1978-2013

Science.gov (United States)

Gorman, Owen T.; Weidel, Brian C.

2014-01-01

The assessment of Great Lakes prey fish stocks have been conducted annually with bottom trawls since the 1970s by the Great Lakes Science Center, sometimes assisted by partner agencies. These stock assessments provide data on the status and trends of prey fish that are consumed by important commercial and recreational fishes. Although all these annual surveys are conducted using bottom trawls, they differ among the lakes in the proportion of the lake covered, seasonal timing, trawl gear used, and the manner in which the trawl is towed (across or along bottom contours). Because each assessment is unique, population indices were standardized to the highest value for a time series within each lake for the following prey species: Cisco (Coregonus artedi), Bloater (C. hoyi), Rainbow Smelt (Osmerus mordax), Alewife (Alosa pseudoharengus), and Round Goby (Neogobius melanostomus). In this report, standardized indices are presented in graphical form along with synopses to provide a short, informal cross-basin summary of the status and trends of principal prey fishes. There was basin-wide agreement in the trends of age-1 and older biomass for all prey species, with the highest concordance occurring for coregonids and Rainbow Smelt, and weaker concordance for Alewife. For coregonids, the highest biomass occurred from the mid-1980s to the mid-1990s. Rainbow Smelt biomass declined slowly and erratically during the last quarter century. Alewife biomass was generally higher from the early 1980s through 1990s across the Great Lakes, but since the early 1990s, trends have been divergent across the lakes, though there has been a downward trend in all lakes since 2005. Recently, Lake Huron has shown resurgence in biomass of Bloater, achieving 75% of its maximum record in 2012 due to recruitment of a succession of strong and moderate year classes that appeared in 2005-2011. Also, strong recruitment of the 2010 year class of Alewife has led to a sharp increase in biomass of Alewife in

Final Supplemental Environmental Impact Statement for Airborne Laser Program at Kirtland Air Force Base (AFB) and White Sands Missile Range/Holloman AFB, NM, and Edwards AFB and Vandenberg AFB, CA

Science.gov (United States)

2003-06-01

californicus- _" -~ T ~ - 1" T - E I T Coho salmon Unarmoured three- spined stickleback I Tidewater goby 1 Eucyclogobius n e w b e p i ,.I...ENDANGERED Black-footed ferret (Mustela nigripes)"" Northern aplomado falcon (Falcofemoralis septentrionalis) Kuenzler hedgehog cachls (Echi...Empidonax traillii ertimus) Kuenzler hedgehog cactus (Echinocer~.~rendleri var. kuenzleri) Todsen’s pennyroyal (Hedeoma fodsenii) Sacramento

Assessing the sensitivity of images in research collections: A new approach at the Wellcome Library.

Science.gov (United States)

Wakely, Helen; Dakin, Carly

2015-06-01

In 2014 The Wellcome Library, part of the Wellcome Trust, introduced a new policy in order to address research access to personal data within its collections. The policy has now been used by library staff for almost a year. The policy was devised using a multi-stage approach which consisted of internal surveys and 1:1 interviews. Library staff can use the policy to guide decisions based on what level of access to award material donated or contributed to the Wellcome collections. The policy has been applied to 1 - a series of victorian medical photographs supplied by University Hospitals Bristol NHS Foundation Trust, and 2 - an album of family photographs from the collection of the psychiatrist Dr Ann Dally. Following almost a year in circulation the advantages and disadvantages can now be summarised.

Empowerment: The Relationship of Women and Power

Directory of Open Access Journals (Sweden)

Magdalena León

2000-01-01

Full Text Available The use of the term 'empowerment' by feminism is closely linked to the importance that social movements as well as social science theory have attributed to the idea of power. For theorists such as Gramsci, Foucault and Paulo Freire, power is a social relationship that is conditioned historically and socially. Even though they do not refer specifically to the power present in gender relations and do not deploy the word "empowerment”, their analyses inspired reflections on that notion by feminist theorists and activists. Since the emergence of the so-called 'second wave' of feminism, the concept of empowerment has been debated by many women's groups. For women's movements, empowerment is a strategy almed at fostering changes in women's dally lives and fomenting the transformation of social structures.

Community shelter use in response to two benthic decapod predators in the Long Island Sound

Directory of Open Access Journals (Sweden)

David M. Hudson

2016-07-01

Full Text Available To investigate community shelter effects of two invasive decapod species, Hemigrapsus sanguineus and Carcinus maenas, in the Long Island Sound (LIS, we deployed artificial shelters in the intertidal and immediate subtidal zones. These consisted of five groups during the summer: a control, a resident H. sanguineus male or female group, and a resident C. maenas male or female group. We quantified utilization of the shelters at 24 h by counting crabs and fish present. We found significant avoidance of H. sanguineus in the field by benthic hermit crabs (Pagurus spp. and significant avoidance of C. maenas by the seaboard goby (Gobiosoma ginsburgi. The grubby (Myoxocephalus aenaeus avoided neither treatment, probably since it tends to be a predator of invertebrates. H. sanguineus avoided C. maenas treatments, whereas C. maenas did not avoid any treatment. Seasonal deployments in the subtidal indicated cohabitation of a number of benthic species in the LIS, with peak shelter use corresponding with increased predation and likely reproductive activity in spring and summer for green crabs (C. maenas, hermit crabs (Pagurus spp., seaboard gobies (G. ginsburgi, and grubbies (Myoxocephalus aenaeus.

Trophic specialization drives morphological evolution in sea snakes.

Science.gov (United States)

Sherratt, Emma; Rasmussen, Arne R; Sanders, Kate L

2018-03-01

Viviparous sea snakes are the most rapidly speciating reptiles known, yet the ecological factors underlying this radiation are poorly understood. Here, we reconstructed dated trees for 75% of sea snake species and quantified body shape (forebody relative to hindbody girth), maximum body length and trophic diversity to examine how dietary specialization has influenced morphological diversification in this rapid radiation. We show that sea snake body shape and size are strongly correlated with the proportion of burrowing prey in the diet. Specialist predators of burrowing eels have convergently evolved a 'microcephalic' morphotype with dramatically reduced forebody relative to hindbody girth and intermediate body length. By comparison, snakes that predominantly feed on burrowing gobies are generally short-bodied and small-headed, but there is no evidence of convergent evolution. The eel specialists also exhibit faster rates of size and shape evolution compared to all other sea snakes, including those that feed on gobies. Our results suggest that trophic specialization to particular burrowing prey (eels) has invoked strong selective pressures that manifest as predictable and rapid morphological changes. Further studies are needed to examine the genetic and developmental mechanisms underlying these dramatic morphological changes and assess their role in sea snake speciation.

Stable isotopes reveal diet shift from pre-extinction to reintroduced Przewalski's horses.

Science.gov (United States)

Kaczensky, Petra; Burnik Šturm, Martina; Sablin, Mikhail V; Voigt, Christian C; Smith, Steve; Ganbaatar, Oyunsaikhan; Balint, Boglarka; Walzer, Chris; Spasskaya, Natalia N

2017-07-20

The Przewalski's horse (Equus ferus przewalskii), the only remaining wild horse within the equid family, is one of only a handful of species worldwide that went extinct in the wild, was saved by captive breeding, and has been successfully returned to the wild. However, concerns remain that after multiple generations in captivity the ecology of the Przewalski's horse and / or the ecological conditions in its former range have changed in a way compromising the species' long term survival. We analyzed stable isotope chronologies from tail hair of pre-extinction and reintroduced Przewalski's horses from the Dzungarian Gobi and detected a clear difference in the isotopic dietary composition. The direction of the dietary shift from being a mixed feeder in winter and a grazer in summer in the past, to a year-round grazer nowadays, is best explained by a release from human hunting pressure. A changed, positive societal attitude towards the species allows reintroduced Przewalski's horses to utilize the scarce, grass-dominated pastures of the Gobi alongside local people and their livestock whereas their historic conspecifics were forced into less productive habitats dominated by browse.

Otolith microchemistry of tropical diadromous fishes: spatial and migratory dynamics

Science.gov (United States)

Smith, William E.; Kwak, Thomas J.

2014-01-01

Otolith microchemistry was applied to quantify migratory variation and the proportion of native Caribbean stream fishes that undergo full or partial marine migration. Strontium and barium water chemistry in four Puerto Rico, U.S.A., rivers was clearly related to a salinity gradient; however, variation in water barium, and thus fish otoliths, was also dependent on river basin. Strontium was the most accurate index of longitudinal migration in tropical diadromous fish otoliths. Among the four species examined, bigmouth sleeper Gobiomorus dormitor, mountain mullet Agonostomus monticola, sirajo goby Sicydium spp. and river goby Awaous banana, most individuals were fully amphidromous, but 9-12% were semi-amphidromous as recruits, having never experienced marine or estuarine conditions in early life stages and showing no evidence of marine elemental signatures in their otolith core. Populations of one species, G. dormitor, may have contained a small contingent of semi-amphidromous adults, migratory individuals that periodically occupied marine or estuarine habitats (4%); however, adult migratory elemental signatures may have been confounded with those related to diet and physiology. These findings indicate the plasticity of migratory strategies of tropical diadromous fishes, which may be more variable than simple categorization might suggest.

Assessment of lake sturgeon (Acipenser fulvescens) spawning efforts in the lower St. Clair River, Michigan

Science.gov (United States)

Nichols, S. Jerrine; Kennedy, Gregory; Crawford, Eric; Allen, Jeffrey; French, John; Black, Glen; Blouin, Marc; Hickey, James P.; Chernyak, Sergei; Haas, Robert; Thomas, Michael

2003-01-01

One of the most threatened remaining populations of lake sturgeon in the Great Lakes is found in the connecting channels between Lake Huron and Lake Erie. Only two spawning grounds are presently known to be active in this region, and both are in the St. Clair River. The spawning reef in the St. Clair River delta has been recently colonized by round gobies (Neogobius melanostomus) in densities up to 25/m2, raising concerns regarding predation on the benthic-oriented eggs and larvae of the sturgeon. Investigations in 1998–1999 showed that while round goby predation does occur, a number of other factors may be equally affecting sturgeon spawning success, including few spawning adults (noted in either year. There were factors other than predation affecting larval survival in 1999. There was a higher silt load on the reef than in 1998 and large numbers of dead larvae were found. Recruitment success from this site could be improved by utilizing techniques to increase the number of eggs on the reef, such as reducing the illegal take of adult fish and by placing eggs in predator-exclusion chambers to increase hatch rate.

Survival of fish after escape from a 40 mm stretched diamond mesh trawl codend in the Aegean Sea

Directory of Open Access Journals (Sweden)

Faik Ozan Düzbastilar

2010-11-01

Full Text Available This study aimed to determine the survival rates of three fish species, the brown comber (Serranus hepatus, black goby (Gobius niger and annular seabream (Diplodus annularis, after their escape from a 40 mm stretched diamond mesh polyethylene (PE codend. Experiments were carried out in the eastern Mediterranean in September 2007 using a conventional bottom trawl with 600 meshes around the mouth. A constant 15 min towing duration was used for all hauls. The towing speed varied between 2.0 and 2.5 knots. Codend covers, supported by two hoops, were used to retain escaping fish. At the end of each haul, these covers were detached from the codend, fixed to the sea floor at depths of 19 to 28 m, and then observed by the divers for a period of seven days. On the eighth day, all of the covers were lifted up and the survivors and mortalities were counted and measured. The mean survival percentages of open codend and experimental cages were found to be 97.1% and 98.3% for brown comber, 69.0% and 77.2% for black goby, and 97.5% and 98.6% for annular seabream respectively.

Growth and reproduction of the pelagic goby Sufflogobius ...

African Journals Online (AJOL)

Two batches of yolked oocytes were present in the ovaries and the maximum ... 2 000 eggs in females 5.0–5.5cm long to about 10 000 in a female 9.8cm long. The mean fecundity was 842 ± 189 eggs per gramme of ovary-free body weight.

A NEW FRESHWATER GOBY (TELEOSTEI: GOBIIDAE) FROM THE ...

African Journals Online (AJOL)

497. JUDB, R. A. 1967. Freshwater fishes of southern Africa. Cape Town: Balkema. KOUMANS, F. P. 1931. A preliminary revision of the genera of the gobioidfishes with united ventral fins. N. V. Lisse. (Netherlands) 1-174: Drukkerij, Imperator. R.

Population genetic diversity of marble goby (Oxyeleotris marmoratus ...

Indian Academy of Sciences (India)

Navya

2017-03-31

Mar 31, 2017 ... Our study will provide valuable information for facilitating the ... traditional method with constructing microsatellite-enriched library (Luo et al. .... important that the protection of wild stock and more wild resources should be ...

Paleolakes in the Gobi region of southern Mongolia

Science.gov (United States)

Lehmkuhl, Frank; Grunert, Jörg; Hülle, Daniela; Batkhishig, Ochirbat; Stauch, Georg

2018-01-01

Numerous lakes and remnants of paleolakes exist in western and southern Mongolia. For six basins in the area, detailed geomorphological maps were compiled, based on extensive field studies and remote sensing datasets. Several phases of high and low lake levels were reconstructed and dated by radiocarbon and optically stimulated luminescence. During the marine isotope stage (MIS) 6 lakes in southern and western Mongolia mostly disappeared. In contrast, large paleolakes existed during the last interglacial (MIS 5e) and lasted probably until the beginning of the last glacial. These huge lakes were caused by a strong East Asian summer monsoon, which reached southern and even western Mongolia. During the MIS 3 the monsoon was considerably weaker and most of the lakes were relatively small or even disappeared. Higher lake levels of this period were only recorded at the Orog Nuur. However, at this time the lake was fed by glacial melt water from the Khangai Mountains. The MIS 2 was again a very dry period. The previously supposed phase of synchronous high lake levels and glaciations in southern and western Mongolia is not supported by the data presented here. During the Holocene, lakes in the western and southern part of the study area evolved differently. Early Holocene high lake levels were reconstructed for the western lakes, while most of the southern lakes had highest lake levels in the mid-Holocene. These differences can be attributed to different moisture bearing atmospheric systems. In the late Holocene lake levels were generally low and in the last 50 years most lakes completely disappeared due to a strong human usage of the water resources.

Reducing organic contamination of shallow areas in brackish lagoons during rearing fish in cages in polyculture

Directory of Open Access Journals (Sweden)

P. Shekk

2017-07-01

Full Text Available Purpose. The development of the technology of the controlled rearing of marine fish remains one of the priority strategic trends of development of national mariculture. A study of the possibility of using polyculture for cage culture has a particular interest. Joint cultivation of several species of fish in the same cage, as practice of fish farming has demonstrated, does not have a tangible positive effect. At the same time, the use of cages of special design can provide significant additional fish products through the use of additional aquaculture objects. The ecological state of water areas, where the cages are located, is of great importance. High fish stocking density and the use of artificial feeds can serve as a source of powerful biogenic and organic pollution, which is especially important for shallow water areas with weak water exchange. The purpose of the study is to develop the methods for joint fish production in cage mariculture capable to provide high fish production and to weaken organic pollution of shallow water areas where cage farms are located. Methodology. The studies were conducted in 1999 and 2004. Cages of special design (internal 10 m3 and external 18.75 m3 installed in the brackish Shabolat Lagoon were used for rearing, steelhead trout, haarder, grass goby and round goby in polyculture. The standard aquaculture research methods were used. For express-analysis of environment hydrochemical parameters in cage location area the following devices were used: "ECOTEST-2000 T" (О2, NO2, NO3, NH4, CO2, phosphates, pH; termooksimetr "АJА-101М" (Т; О2; "pH meter-150 M; Refractometer "ATAGO-100" (salinity and water density. Findings. The results of marine fish cultivation in cages in polyculture in the shallow Shabolat lagoon are presented. It has been shown that joint cultivation of salmon, mullet and gobies in specially designed cages in shallow marine lagoons allows using artificial and natural feeds more fully and

Functional type 2 photosynthetic reaction centers found in the rare bacterial phylum Gemmatimonadetes

OpenAIRE

Zeng, Yonghui; Feng, Fuying; Medová, Hana; Dean, Jason; Koblížek, Michal

2014-01-01

Photosynthesis is one of the most fundamental biological processes on Earth. To date, species capable of performing (bacterio)chlorophyll-based phototrophy have been reported in six bacterial phyla. Here we report a phototrophic bacterium belonging to the rare and understudied phylum Gemmatimonadetes. This strain, isolated from a freshwater lake in the Gobi Desert, contains fully functional photosynthetic reaction centers. Its photosynthesis genes appear to originate from an ancient horizonta...

Guidance for organizing a local radiation protection program in medical care

International Nuclear Information System (INIS)

Sarby, B.; Jorulf, H.

2000-12-01

The following report is intended to be a guidance of how to organize a local radiation protection program and how it can be incorporated into daily medical care. The report is based on knowledge derived from participation and observations from inspections and the experience from hospitals who for a long time have been working in a well documented organisation. The organisation is described in local. The aim with these documents is to achieve a clear distribution of duties and responsibilities between the licence holder and directors concerned. Furthermore, a basic thought is to establish an efficient form of collaboration between the diverse staff categories and to achieve continuity in the embodiment of new laws and regulations. At that it is important to organise 'the local radiation committee' to operate in close collaboration with the dally medical care

Dual impact of temperature on growth and mortality of marine fish larvae in a shallow estuarine habitat

Science.gov (United States)

Arula, Timo; Laur, Kerli; Simm, Mart; Ojaveer, Henn

2015-12-01

High individual growth and mortality rates of herring Clupea harengus membras and goby Pomatoschistus spp. larvae were observed in the estuarine habitat of the Gulf of Riga, Baltic Sea. Both instantaneous mortality (0.76-1.05) as well as growth rate (0.41-0.82 mm day-1) of larval herring were amongst highest observed elsewhere previously. Mortality rates of goby larvae were also high (0.57-1.05), while first ever data on growth rates were provided in this study (0.23-0.35 mm day-1). Our study also evidenced that higher growth rate of marine fish larvae did not result in lower mortalities. We suggest that high growth and mortality rates primarily resulted from a rapidly increasing and high (>18 °C) water temperature that masked potential food-web effects. The explanation for observed patterns lies in the interactive manner temperature contributed: i) facilitating prey production, which supported high growth rate and decreased mortalities; ii) exceeding physiological thermal optimum of larvae, which resulted in decreased growth rate and generally high mortalities. Our investigation suggests that the projected climate warming may have significant effect on early life history stages of the dominating marine fish species inhabiting shallow estuaries.

Inheritance patterns of morphological laterality in mouth opening of zebrafish, Danio rerio.

Science.gov (United States)

Hata, Hiroki; Hori, Michio

2012-01-01

The inheritance patterns of asymmetry in mouth opening in zebrafish were investigated using crossing experiments. Zebrafish exhibit asymmetric laterality in mouth opening, with each individual having either a leftward (righty) or rightward (lefty) bias. All righty incrosses produced only righty F(1), whereas all lefty incrosses resulted in an F(1) L:R ratio of 2:1. All test crosses between lefty and righty individuals resulted in an F(1) L:R=1:1. These results were consistent with the hereditary pattern for Japanese medaka, three Tanganyikan cichlids, and a Japanese riverine goby. The pattern suggests a one-locus two-allele Mendelian model of inheritance, with the lefty allele being dominant over righty and the dominant homozygote being lethal. To determine the reason for the absence of lefty homozygotes, the survival rates of the offspring were examined according to developmental stage. Survival did not differ among combinations of parent laterality. Thus the mechanism underlying the lethality of the dominant homozygote remains unclear. This study showed that the mouth-opening laterality of zebrafish is genetically determined and that the direction follows a Mendelian inheritance pattern that is shared among cypriniform zebrafish, beloniform medaka, perciform cichlids, and a goby, suggesting a common genetic background in mouth-opening laterality among these species.

Jaw muscle fiber type distribution in Hawaiian gobioid stream fishes: histochemical correlations with feeding ecology and behavior.

Science.gov (United States)

Maie, Takashi; Meister, Andrew B; Leonard, Gerald L; Schrank, Gordon D; Blob, Richard W; Schoenfuss, Heiko L

2011-12-01

Differences in fiber type distribution in the axial muscles of Hawaiian gobioid stream fishes have previously been linked to differences in locomotor performance, behavior, and diet across species. Using ATPase assays, we examined fiber types of the jaw opening sternohyoideus muscle across five species, as well as fiber types of three jaw closing muscles (adductor mandibulae A1, A2, and A3). The jaw muscles of some species of Hawaiian stream gobies contained substantial red fiber components. Some jaw muscles always had greater proportions of white muscle fibers than other jaw muscles, independent of species. In addition, comparing across species, the dietary generalists (Awaous guamensis and Stenogobius hawaiiensis) had a lower proportion of white muscle fibers in all jaw muscles than the dietary specialists (Lentipes concolor, Sicyopterus stimpsoni, and Eleotris sandwicensis). Among Hawaiian stream gobies, generalist diets may favor a wider range of muscle performance, provided by a mix of white and red muscle fibers, than is typical of dietary specialists, which may have a higher proportion of fast-twitch white fibers in jaw muscles to help meet the demands of rapid predatory strikes or feeding in fast-flowing habitats. Copyright © 2011 Elsevier GmbH. All rights reserved.

Neurohypophysial Hormones Regulate Amphibious Behaviour in the Mudskipper Goby.

Science.gov (United States)

Sakamoto, Tatsuya; Nishiyama, Yudai; Ikeda, Aoi; Takahashi, Hideya; Hyodo, Susumu; Kagawa, Nao; Sakamoto, Hirotaka

2015-01-01

The neurohypophysial hormones, arginine vasotocin and isotocin, regulate both hydromineral balance and social behaviors in fish. In the amphibious mudskipper, Periophthalmus modestus, we previously found arginine-vasotocin-specific regulation of aggressive behavior, including migration of the submissive subordinate into water. This migration also implies the need for adaptation to dehydration. Here, we examined the effects of arginine vasotocin and isotocin administration on the amphibious behavior of individual mudskippers in vivo. The mudskippers remained in the water for an increased period of time after 1-8 h of intracerebroventricular (ICV) injection with 500 pg/g arginine vasotocin or isotocin. The 'frequency of migration' was decreased after ICV injection of arginine vasotocin or isotocin, reflecting a tendency to remain in the water. ICV injections of isotocin receptor antagonist with arginine vasotocin or isotocin inhibited all of these hormonal effects. In animals kept out of water, mRNA expression of brain arginine vasotocin and isotocin precursors increased 3- and 1.5-fold, respectively. Given the relatively wide distribution of arginine vasotocin fibres throughout the mudskipper brain, induction of arginine vasotocin and isotocin under terrestrial conditions may be involved also in the preference for an aquatic habitat as ligands for brain isotocin receptors.

Neurohypophysial Hormones Regulate Amphibious Behaviour in the Mudskipper Goby.

Directory of Open Access Journals (Sweden)

Tatsuya Sakamoto

Full Text Available The neurohypophysial hormones, arginine vasotocin and isotocin, regulate both hydromineral balance and social behaviors in fish. In the amphibious mudskipper, Periophthalmus modestus, we previously found arginine-vasotocin-specific regulation of aggressive behavior, including migration of the submissive subordinate into water. This migration also implies the need for adaptation to dehydration. Here, we examined the effects of arginine vasotocin and isotocin administration on the amphibious behavior of individual mudskippers in vivo. The mudskippers remained in the water for an increased period of time after 1-8 h of intracerebroventricular (ICV injection with 500 pg/g arginine vasotocin or isotocin. The 'frequency of migration' was decreased after ICV injection of arginine vasotocin or isotocin, reflecting a tendency to remain in the water. ICV injections of isotocin receptor antagonist with arginine vasotocin or isotocin inhibited all of these hormonal effects. In animals kept out of water, mRNA expression of brain arginine vasotocin and isotocin precursors increased 3- and 1.5-fold, respectively. Given the relatively wide distribution of arginine vasotocin fibres throughout the mudskipper brain, induction of arginine vasotocin and isotocin under terrestrial conditions may be involved also in the preference for an aquatic habitat as ligands for brain isotocin receptors.

Daily feeding periodicity of the intertidal goby Caffrogobius caffer

African Journals Online (AJOL)

en laagwater. Voedsel is dwarsdeur die dag ingeneem en daar is 'n effense neiging tot hoogtepunte in die voedingsaktiwiteit gedurende skemertye. S.·Afr. Tydskr. ... These two phenomena, tide and light intensi- ty, might be expected to have an effect on the feeding periodicity of C. coffer. Twenty-four-hour collections were ...

INVESTIGATION OF LITHOSPHERIC STRUCTURE IN MONGOLIA: INSIGHTS FROM INSAR OBSERVATIONS AND MODELLING

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Z. Jing

2017-09-01

Full Text Available The western Mongolia is a seismically active intracontinental region, with ongoing tectonic deformation and widespread seismicity related to the far-field effects of India-Eurasia collision. During the 20th century, four earthquakes with the magnitude larger than 8 occurred in the western Mongolia and its surrounding regions, providing a unique opportunity to study the geodynamics of intracontinental tectonic deformations. The 1957 magnitude 8.3 Gobi-Altai earthquake is one of the largest seismic events. The deformation pattern of rupture zone associated with this earthquake is complex, involving left-lateral strike-slip and reverse dip-slip faulting on several distinct geological structures in a 264 × 40 km wide zone. To understand the relationship between the observed postseismic surface deformation and the rheological structure of the upper lithosphere, Interferometric Synthetic Aperture Radar (InSAR data are used to study the 1957 earthquake. Then we developed a postseismic model in a spherical, radially layered elastic-viscoelastic Earth based on InSAR results, and further analysed the dominant contribution to the surface deformation. This work is important for understanding not only the regional tectonics, but also the structure and dynamics of the lithosphere. SAR data were acquired from the ERS1/2 and Envisat from 1996 to 2010. Using the Repeat Orbit Interferometry Package (ROI_PAC, 124 postseismic interferograms are produced on four adjacent tracks. By stacking these interferograms, the maximum InSAR line-of-sight deformation rate along the Gobi-Altai fault zone is obtained. The main results are as follows: (1 The maximum InSAR line-of-sight deformation velocity along this large fault zone is about 6 mm/yr; (2 The modelled surface deformation suggests that the viscoelastic relaxation is the most reasonable mechanism to explain the observed surface motion; (3 The optimal model cover the Gobi-Altai seismogenic thickness is 10�

SALINITAS OPTIMAL UNTUK PENDEDERAN BENIH IKAN BETUTU (Oxyeleotris marmorata

Directory of Open Access Journals (Sweden)

Idil Ardi

2017-01-01

Full Text Available Ikan betutu (Oxyeleotris marmorata termasuk ikan perairan tawar yang memiliki nilai ekonomis penting dan sangat disukai karena memiliki daging yang tebal, tulangnya sedikit, dan gurih. Salah satu faktor lingkungan yang berpengaruh dalam kegiatan budidaya adalah salinitas. Penelitian bertujuan untuk mendapatkan salinitas optimum dalam pemeliharaan benih ikan betutu yang diharapkan dapat meningkatkan sintasan dan pertumbuhannya. Penelitian menggunakan rancangan acak lengkap (RAL dengan empat perlakukan berdasarkan perbedaan salinitas yaitu kontrol ppt, 1 ppt, 3 ppt, dan 5 ppt. Setiap perlakuan dilakukan tiga kali pengulangan. Hasil penelitian menunjukkan terdapat perbedaan nyata (P<0,05 terhadap laju pertumbuhan spesifik, panjang mutlak, bobot mutlak, dan kadar glukosa darah terhadap kontrol (salinitas 0 ppt setelah dipelihara selama 56 hari. Laju pertumbuhan mutlak, bobot mutlak, dan glukosa darah paling baik dijumpai pada benih yang dipelihara dengan salinitas 3 ppt, yaitu 0,94 ± 0,09%; 2,53 ± 0,35 mm; 37,33 ± 6,28 g; dan 0,06 ± 0,01 g/dL. Pemeliharaan benih betutu membutuhkan air bersalinitas. Untuk mengoptimalkan pertumbuhan dan sintasan air media budidaya disarankan bersalinitas 3 ppt. Sand goby (Oxyeleotris marmorata is one of freshwater fish that has high economic value and is more desired for its thick meat, bone less, and tasteful. Salinity is one of the most important environmental factors in fish culture. The purpose of this study was to determine the optimal salinity concentration on growth and survival of sand goby fish. A completely Randomized Design (CRD was used in this study with four treatments of salinity levels comprising A Control; B 1 ppt; C 3 ppt; D 5 ppt. Each treatment was consisted of three replicates. The result showed significant differences (P<0.05 in specific growth rate, absolute length, absolute weight, and blood glucose among the treatments against control after 56 days cultured. Seed reared under the salinity

Carrier of Wingless (Cow), a Secreted Heparan Sulfate Proteoglycan, Promotes Extracellular Transport of Wingless

Science.gov (United States)

Chang, Yung-Heng; Sun, Yi Henry

2014-01-01

Morphogens are signaling molecules that regulate growth and patterning during development by forming a gradient and activating different target genes at different concentrations. The extracellular distribution of morphogens is tightly regulated, with the Drosophila morphogen Wingless (Wg) relying on Dally-like (Dlp) and transcytosis for its distribution. However, in the absence of Dlp or endocytic activity, Wg can still move across cells along the apical (Ap) surface. We identified a novel secreted heparan sulfate proteoglycan (HSPG) that binds to Wg and promotes its extracellular distribution by increasing Wg mobility, which was thus named Carrier of Wg (Cow). Cow promotes the Ap transport of Wg, independent of Dlp and endocytosis, and this function addresses a previous gap in the understanding of Wg movement. This is the first example of a diffusible HSPG acting as a carrier to promote the extracellular movement of a morphogen. PMID:25360738

A new discovery of Glossopteris in southeastern Mongolia as an argument for distant migration of Gondwanan plants

Science.gov (United States)

Naugolnykh, Serge V.; Uranbileg, L.

2018-04-01

Well-preserved leaves conforming to the fossil genus Glossopteris are found in the Permian deposits of southeastern Gobi, Khatan-Bulag locality, Mongolia. These leaves have many features in common with Glossopteris communis Feistmantel described from India. The locality Khatan-Bulag belongs to Sulinkheer nappe-fold tectonic megazone. The Glossopteris sp. cf. G. communis specimens from the Khatan-Bulag suggest that there was effective migration gateway between Gondwana and southern regions of Asia in the mid-Permian.

Unravelling the secret of the resistance of desert strains of Chroococcidiopsis to desiccation and radiation

OpenAIRE

Billi, Daniela; Fagliarone; Verseux, Cyprien; Mosca, Claudia; Baqué, Mickael; Wilmotte, Annick

2017-01-01

Chroococcidiopsis is a unicellular cyanobacterial genus that is growing in extreme dry conditions, either in low or high temperatures. At the lower end of the spectrum, they live as cryptoendoliths in rocks of the Mc Murdo Dry Valleys in Antarctica where they were discovered by Imre Friedmann, while at the higher end, they grow as hypoliths/endoliths in hot deserts, e.g. Negev, Gobi, Atacama (Friedman, 1980). The capacity of desert strains of Chroococcidiopsis to stabilize their sub-cellul...

Characteristics of Land Use/Cover and Macroscopic Ecological Changes in the Headwaters of the Yangtze River and of the Yellow River over the Past 30 Years

Directory of Open Access Journals (Sweden)

Lulu Liu

2016-03-01

Full Text Available Based on land use and land cover (LULC datasets in the late 1970s, the early 1990s, 2004 and 2012, we analyzed characteristics of LULC change in the headwaters of the Yangtze River and Yellow River over the past 30 years contrastively, using the transition matrix and LULC change index. The results showed that, in 2012, the LULC in the headwaters of the Yellow River were different compared to those of the headwaters of the Yangtze River, with more grassland and wet- and marshland. In the past 30 years, the grassland and wet- and marshland increasing at the expense of sand, gobi, and bare land and desert were the main LULC change types in the headwaters of the Yangtze River, with the macro-ecological situation experiencing a process of degeneration, slight melioration, and continuous melioration, in that order. In the headwaters of the Yellow River, severe reduction of grassland coverage, shrinkage of wet- and marshland and the consequential expansion of sand, gobi and bare land were noticed. The macro-ecological situation experienced a process of degeneration, obvious degeneration, and slight melioration, in that order, and the overall change in magnitude was more dramatic than that in the headwaters of the Yangtze River. These different LULC change courses were jointly driven by climate change, grassland-grazing pressure, and the implementation of ecological construction projects.

Preliminary Insight into Winter Native Fish Assemblages in Guadiana Estuary Salt Marshes Coping with Environmental Variability and Non-Indigenous Fish Introduction

Directory of Open Access Journals (Sweden)

Renata Gonçalves

2017-10-01

Full Text Available This work aims to undertake a preliminary characterization of winter fish assemblages in the salt marsh areas of Guadiana lower estuary (South-East Portugal and discusses the potential risks of habitat dominance by a non-indigenous species (NIS. To this effect, six field campaigns were carried out in four sampling sites during winter season targeting the collection of fish species. A total of 48 samples were collected. Individuals from seven different taxa (marine and estuarine were collected, although the assemblage was dominated by two estuarine species—the native Pomatoschistus sp. (goby and the NIS Fundulus heteroclitus (mummichog. Goby was the most abundant taxa in the majority of salt marsh habitats, except for one specific, marsh pool, where extreme environmental conditions were registered, namely high temperature and salinity. Such conditions may have boosted the intrusion of mummichog in this area. This species is well adapted to a wide range of abiotic factors enabling them to colonize habitats where no predators inhabit. Impacts of mummichog introduction in the Guadiana salt marsh area are still unpredictable since this is the first time they have been recorded in such high density. Nevertheless, in scenarios of increased anthropogenic pressure and, consequently, habitat degradation, there is a potential risk of mummichog spreading to other habitats and therefore competing for space and food resources with native species.

Dynamic modeling predicts continued bioaccumulation of polybrominated diphenyl ethers (PBDEs) in smallmouth bass (Micropterus dolomiu) post phase-out due to invasive prey and shifts in predation

International Nuclear Information System (INIS)

Wallace, Joshua S.; Blersch, David M.

2015-01-01

Unprecedented food chain links between benthic and pelagic organisms are often thought to disrupt traditional contaminant transport and uptake due to changes in predation and mobilization of otherwise sequestered pollutants. A bioaccumulation model for polybrominated diphenyl ethers (PBDEs) is developed to simulate increases in biotic congener loads based upon trophic transfer through diet and gill uptake for a Lake Erie food chain including two invasive species as a benthic-pelagic link. The model utilizes species-specific bioenergetic parameters in a four-level food chain including the green alga Scenedesmus quadricauda, zebra mussels (Dreissena polymorpha), round goby (Appollonia melanostoma), and the smallmouth bass (Micropterus dolomiu). The model was calibrated to current biotic concentrations and predicts an increase in contaminant load by almost 48% in the upper trophic level in two years. Validation to archival data resulted in <2% error from reported values following a two-year simulation. - Highlights: • A dynamic model assesses continued bioaccumulation of PBDEs in predators of invasive prey. • The model incorporates novel benthic-pelagic energy links due to invasive prey. • Increases in total PBDEs in smallmouth bass due to invasive energy pathways are simulated. • The model is validated to archival data obtained prior to invasion of zebra mussels and round goby. - A dynamic model is developed to simulate continued bioaccumulation of polybrominated diphenyl ethers (PBDEs) in smallmouth bass due to emerging benthic-pelagic energy pathways.

Investigation of Three-Dimensional Evolution of East Asian Dust Storm by Modeling and Remote Sensing Measurements

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Jiawei Li

2015-01-01

Full Text Available The three-dimensional evolution of an East Asian dust storm during 23–26 April 2009 was investigated by utilizing a regional air quality model system (RAQMS and satellite measurements. This severe dust storm hit Mt. Tai in east China with daily mean PM10 concentration reaching 1400 μg/m3 and the model captured the PM10 variation reasonably well. Modeled spatial distributions of AOD and vertical profiles of aerosol extinction coefficient during the dust storm were compared with MODIS and CALIPSO data, demonstrating that RAQMS was able to reproduce the 3D structure and the evolution of the dust storm reasonably well. During early days of the dust storm, daily mean dust-induced AOD exceeded 2.0 over dust source regions (the Gobi desert and the Taklamakan desert and was in a range of 1.2–1.8 over the North China Plain, accounting for about 98% and up to 90% of total AOD over corresponding areas, respectively. The top of the dust storm reached about 8 km over east China, with high dust concentration locating at around 40°N. Dust aerosol below 2 km was transported southeastward off the Gobi desert while dust above 2 km was transported out of China along 40°–45°N.

Redescription of Coryphopterus tortugae (Jordan) and a new allied species Coryphopterus bol (Perciformes: Gobiidae: Gobiinae) from the tropical western Atlantic Ocean

OpenAIRE

Victor, Benjamin C.

2008-01-01

A re-examination of the holotype and mtDNA barcoding confirms Garzon-Ferreira and Acero’s separation of Coryphopterus tortugae from C. glaucofraenum. However, specimens matching the markings of their Santa Marta variant of C. tortugae comprise a distinct clade about 10% sequence divergent from true C. tortugae and C. glauco-fraenum. The variant is described here as a new species, the sand-canyon goby Coryphopterus bol, from specimens collected in Puerto Rico, the US Virgin Islands, and the At...

Preconstruction Biogeochemical Analysis of Mercury in Wetlands Bordering the Hamilton Army Airfield (HAAF) Wetlands Restoration Site. Part 3

Science.gov (United States)

2009-12-01

but not included in the analyzed samples, were zooplankton, bacteria, and larvae for the Asian clam and mysids for the shrimp (Table 5-4). The...Asian clam, shrimp , goby) may contribute the most, while the central role of detritus-associated MeHg has to be further explored. The Questions and...Asian clam) Bay 1 -20.9 (-) 11.6 (-) 13.3 (-) Shrimp sp. Bay 6 -19.6 (0.4) 15.4 (1.6) 14.7 (1.4) Carcinus maenas (European green crab) Bay

Distribución de Sicydium Valenciennes 1837 (Pisces: Gobiidae) en México y Centro América

OpenAIRE

Lyons, John

2005-01-01

Gobies of the genus Sicydium Valenciennes are widespread in Mexico and Central America, but have a different distribution pattern on the Atlantic and Pacific slopes of the region. On the Pacific slope, where mountain ranges are found near the coast and the coastal plain is narrow, Sicydium is continuously distributed in rivers from Mazatlán, Sinaloa, Mexico, to central Panama. On the Atlantic slope, Sicydium is known from to three disjunct areas where coastal mountain ranges are present, cent...

The fate of chylomicron cholesterol in the rat. 1. research into the storing of chylomicrons (1961)

International Nuclear Information System (INIS)

Chevallier, F.; Maurice, J.P.

1961-01-01

Rats conditioned to take their dally meal between midnight and 2 a.m. are given at midnight, by stomach tubing, 0,5 mg 4- 14 C-cholesterol, and are sacrificed in the following hours. During the most active phase of intestinal absorption, specific radioactivities of free and esterified liver cholesterol and of serum cholesterol are practically equal. Consequently, captation of absorbed cholesterol by the liver is not detectable. The results obtained exclude, on the other hand, the possibility that the lungs might play a similar role. The problem of the fate of chylomicron cholesterol is discussed. In order to avoid any ambiguity in this discussion, we have determined the concentration and specific radioactivity of free and esterified cholesterol in chylomicrons and lymph obtained by continuous drainage of chyle. 5 p. 100 of the radioactive cholesterol of chyle are found in lymph: in chylomicrons, the radioactivity of free cholesterol is higher than that of esterified cholesterol. (authors) [fr

Evaluation of the nuclear security culture

International Nuclear Information System (INIS)

Spitalnik, Jorge

2003-01-01

The security culture of an organization resides in its workers and it is expressed by the way the personnel that works in a particular organization practice daily its activities. The security culture can be practice in a high or in a low level, but it always exists and it can always be improved. It is based on the security condition and procedures that have been established in the planning phase and in the implementation of a project. After its implantation, in order to avoid deterioration, basically it is necessary to maintain and to bring updated those conditions and procedures through strategies of follow up and control. This process establishes the basis of a program of maintenance and improvement of the Security Culture. Many self-evaluations that have been accomplished at nuclear organizations based on workers perception concerning working conditions and management environment, have permitted objectively determine if the security doctrine, which the organization assure to follow rigorously into its dally activities, is really so (LS)

El filibusterismo en los mensajes al Congreso de los presidentes de los Estados Unidos y la Ley de Neutralidad 1848-1860

OpenAIRE

Fallas Santana, Carmen María

2011-01-01

En este artículo se analiza el abordaje del filibusterismo en los mensajes al Congreso de los presidentes de Estados Unidos en el periodo comprendido entre el fin de la guerra con México y el inicio de la Guerra Civil. Argumenta que todas las administraciones declararon su compromiso de suprimir el filibusterismo porque era perjudicial para los intereses comerciales, políticos y económicos, la seguridad nacional y las relaciones exteriores. Señala que el rechazo de las peticiones de los gobie...

Dust Propagation and Radiation In the Presence of a Low-level Jet in Central China on March 17, 2010

Science.gov (United States)

McDowell, B. K.; Chen, S. H.

2014-12-01

Suspended dust in the air can directly change the energy budget in the atmosphere and at the surface through scattering and absorption of radiation. Thus, dust can potentially modify the development of weather systems. To explore the dust-radiation effects on weather systems, a dust model was developed based on the Weather Research and Forecasting (WRF) model. The calculations of dust processes in the WRF dust model include emission, advection, boundary layer mixing, cumulus mixing, dust-radiation interaction, wet scavenging, and sedimentation. Due to a high vertical spatial resolution near the surface a time splitting method was applied to the calculation of dust sedimentation to relax the numerical time step. The "Hexi Corridor" is the historical name given to a string of oases along the northern slope of the Tibetan Plateau that formed a relatively easy transportation route between eastern China and central Asia. As trade developed over the centuries, this route became known as the Silk Road. This corridor also marks the transition from the relatively flat Gobi desert area in northern China to the elevated mountains of the Tibetan Plateau. These mountains present a southern barrier to the paths of dust storms that develop during spring outbreaks of the Mongolian Cyclone. In March of 2010, a series of dust storms developed in the Gobi Desert north of the Hexi Corridor that transported massive amounts of dust eastward to central and northeastern China, Korea and Japan. On March 17 during this event, a low-level jet developed along the northern perimeter of the Plateau, in alignment with upper level winds and the Hexi Corridor. Over the course of the day, a well-defined short-duration dust plume was emitted in the southern Gobi desert area and was transported over 1300 km in a southeast direction, over the Loess Plateau and into the Gansu Province. In this study, the interactions of synoptic conditions with regional topography that led to the development of the low

Status and trends of prey fish populations in Lake Michigan, 2013

Science.gov (United States)

Madenjian, Charles P.; Bunnell, David B.; Desorcie, Timothy J.; Kostich, Melissa Jean; Armenio, Patricia M.; Adams, Jean V.

2015-01-01

The U.S. Geological Survey Great Lakes Science Center has conducted lake-wide surveys of the fish community in Lake Michigan each fall since 1973 using standard 12-m bottom trawls towed along contour at depths of 9 to 110 m at each of seven index transects. The resulting data on relative abundance, size and age structure, and condition of individual fishes are used to estimate various population parameters that are in turn used by state and tribal agencies in managing Lake Michigan fish stocks. All seven established index transects of the survey were completed in 2013. The survey provides relative abundance and biomass estimates between the 5-m and 114-m depth contours of the lake (herein, lake-wide) for prey fish populations, as well as burbot, yellow perch, and the introduced dreissenid mussels. Lake-wide biomass of alewives in 2013 was estimated at 29 kilotonnes (kt, 1 kt = 1000 metric tonnes), which was more than three times the 2012 estimate. However, the unusually high standard error associated with the 2013 estimate indicated no significant increase in lake-wide biomass between 2012 and 2013. Moreover, the age distribution of alewives remained truncated with no alewife exceeding an age of 5. The population of age-1 and older alewives was dominated (i.e., 88%) by the 2010 and 2012 year-classes. Record low biomass was observed for deepwater sculpin (1.3 kt) and ninespine stickleback (0.004 kt) in 2013, while bloater (1.6 kt) and rainbow smelt (0.2 kt) biomasses remained at low levels. Slimy sculpin lake-wide biomass was 0.32 kt in 2013, marking the fourth consecutive year of a decline. The 2013 biomass of round goby was estimated at 10.9 kt, which represented the peak estimate to date. Burbot lake-wide biomass (0.4 kt in 2013) has remained below 3 kt since 2001. Numeric density of age-0 yellow perch (i.e., fish per ha, which is indicative of a relatively poor year-class. Lake-wide biomass estimate of dreissenid mussels in 2013 was 23.2 kt. Overall, the total

Expansion of round gobies in a non-navigable river system

Czech Academy of Sciences Publication Activity Database

Šlapanský, Luděk; Janáč, Michal; Roche, Kevin Francis; Mikl, Libor; Jurajda, Pavel

2017-01-01

Roč. 67, November (2017), s. 27-36 ISSN 0075-9511 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Impact * Invasive species * Neogobius melanostomus * Pioneer fish * Population characteristics * Proterorhinus semilunaris Subject RIV: EH - Ecology, Behaviour OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 1.427, year: 2016

Tactic-specific differences in seminal fluid influence sperm performance.

Science.gov (United States)

Locatello, Lisa; Poli, Federica; Rasotto, Maria B

2013-03-22

Seminal fluid often makes up a large part of an ejaculate, yet most empirical and theoretical studies on sperm competition have focused on how sperm characteristics (number and quality) affect fertilization success. However, seminal fluid influences own sperm performance and may potentially influence the outcome of sperm competition, by also affecting that of rivals. As a consequence males may be expected to allocate their investment in both sperm and seminal fluid in relation to the potential level of competition. Grass goby (Zosterisessor ophiocephalus) is an external fertilizer with guard-sneaker mating tactics, where sperm competition risk varies according to the tactic adopted. Here, we experimentally manipulated grass goby ejaculates by separately combining sperm and seminal fluid from territorial and sneaker males. While sperm of sneaker and territorial males did not differ in their performance when they interacted with their own seminal fluid only, sperm of sneakers increased their velocity and fertilization rate in the presence of territorial males' seminal fluid. By contrast, sneaker males' seminal fluid had a detrimental effect on the performance of territorial males' sperm. Sperm velocity was unaffected by the seminal fluid of males employing the same tactic, suggesting that seminal fluid's effect on rival-tactic sperm is not based on a self/non-self recognition mechanism. Our findings show that cross interactions of sperm and seminal fluid may influence the fertilization success of competing ejaculates with males investing in both sperm and seminal fluid in response to sperm competition risk.

Indicator polychlorinated biphenyl residues in muscle tissue of fish from Black Sea coast of Bulgaria

Directory of Open Access Journals (Sweden)

S. Georgieva

2016-06-01

Full Text Available Abstract. Polychlorinated biphenyls (PCBs are characterized by high lipophilicity and persistence in the environment and will therefore bioaccumulate and biomagnify in the food chain. PCBs were determined in muscle tissue of four fish species: goby (Neogobius melanostomus, horse mackerel (Trachurus Mediterraneus ponticus, shad (Alosa pontica pontica and turbot (Psetta maxima maeotica. Samples were collected from Bulgarian Black Sea coast during 2007 – 2011. The PCBs were analyzed in order to examine the time trends of PCB concentrations in fish from Black Sea. The six individual PCBs congeners were determined by capillary gas chromatography system with mass spectrometry detection. PCBs were found in all fish species at concentrations ranging between 2.32 ng/g ww (wet weight and 32.87 ng/g ww in goby and shad, respectively. PCB profiles have been found to be similar in all the fish species tested. The most abundant PCB congeners in fish species were hexa- and heptachlorinated PCBs 138, 153 and 180. PCB 153 was the dominant congener in all fish studied and were found in the range from 0.95 ng/g ww (horse mackerel 2011 to 11.67 ng/g ww (shad 2010. The sum of six indicator PCBs in all fish species did not exceed the European maximum limit of 75 ng/g ww. The levels of PCBs in fish from Bulgarian Black Sea coast were found lower than in fish species from other seas – the Aegean Sea and the Mediterranean Sea.

"Poder Ciudadano" e tutela dell'Etica Pubblica nella Costituzione Venezuelana del 1999

OpenAIRE

Claudia Esposito

2011-01-01

El objetivo de esta investigación es analizar los temas desarrolados sobre el papel de la Ética Pública en una democracia moderna. En primer lugar se analiza la introducción del Poder Ciudadano y en particular del Defensor del Pueblo en la Constitución Venezolana de 1999, como medio no jurisdicional de tutela de los derechos humanos. El método adoptado es de tipo documental. En las conclusiones se resalta la importancia de la Ética publica como medio de participación de los ciudadanos al gobi...

Evaluating dispersal potential of an invasive fish by the use of aerobic scope and osmoregulation capacity

DEFF Research Database (Denmark)

Behrens, Jane W.; Deurs, Mikael van; Christensen, Emil Aputsiaq Flindt

2017-01-01

factors such as presence of predators, competitors, and parasites. Early prediction of dispersal potential and future 'area of impact' is challenging, but also a great asset in taking appropriate management actions. Aerobic scope (AS) in fish has been linked to various fitness-related parameters, and may...... waters is unknown to date. We show that AS in round goby is reduced by 30% and blood plasma osmolality increased (indicating reduced capacity for osmoregulation) at salinities approaching oceanic conditions, following slow ramping (5 PSU per week) and subsequent long-term acclimation to salinities...

Impacto del buen gobierno corporativo en la generación de valor financiero de empresas representativas del sector cementero de Perú y Colombia

OpenAIRE

Borda Guerra, Alex; Gago Martínez, Angélica; Masuda Cáceres, Vicente; Viviano Bustinza, Magin

2017-01-01

x, 184 h. : il. ; 30cm. La presente tesis realiza el análisis de las empresas representativas del sector cementero de Perú y Colombia con prácticas de buen gobierno corporativo y su implicancia en la generación de valor financiero a partir de la revisión de los reportes o códigos de gobierno corporativo y estados financieros auditados publicados en medios oficiales por las empresas que conforman el estudio. Una vez que se recopiló la información de las prácticas de buen gobi...

The basic features of clay rock in Tamusu area

International Nuclear Information System (INIS)

Liu Xiaodong; Liu Pinghui

2012-01-01

This paper introduces the Tamusu area location, natural and social economic situation, the regional geological background, as well as the upper Gobi formation of clay rocks, and from the geological conditions, economic conditions, social conditions and other aspects of the Tamusu claystone conducted a preliminary evaluation. The results showed that this area can be used as one of the favorable preselected areas for high-level radioactive waste geological disposal repository, basically meets the siting criteria for geological conditions, environmental protection, land use, social influence and waste transport etc. (authors)

Seasonal variation in male alternative reproductive tactics.

Science.gov (United States)

Monroe, M J; Amundsen, T; Utne-Palm, A C; Mobley, K B

2016-12-01

Genetic parentage analyses reveal considerable diversity in alternative reproductive behaviours (e.g. sneaking) in many taxa. However, little is known about whether these behaviours vary seasonally and between populations. Here, we investigate seasonal variation in male reproductive behaviours in a population of two-spotted gobies (Gobiusculus flavescens) in Norway. Male two-spotted gobies guard nests, attract females and care for fertilized eggs. We collected clutches and nest-guarding males early and late in the breeding season in artificial nests and used microsatellite markers to reconstruct parentage from a subset of offspring from each nest. We hypothesized that mating, reproductive success and sneaking should be more prevalent early in the breeding season when competition for mates among males is predicted to be higher. However, parentage analyses revealed similar values of mating, reproductive success and high frequencies of successful sneaking early (30% of nests) and late (27% of nests) in the season. We also found that multiple females with eggs in the same nest were fertilized by one or more sneaker males, indicating that some males in this population engage in a satellite strategy. We contrast our results to previous work that demonstrates low levels of cuckoldry in a population in Sweden. Our results demonstrate marked stability in both the genetic mating system and male alternative reproductive tactics over the breeding season. However, sneaking rates may vary geographically within a species, likely due to local selection influencing ecological factors encountered at different locations. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

The use of environmental DNA in invasive species surveillance of the Great Lakes commercial bait trade.

Science.gov (United States)

Nathan, Lucas R; Jerde, Christopher L; Budny, Michelle L; Mahon, Andrew R

2015-04-01

Over 180 non-native species have been introduced in the Laurentian Great Lakes region, many posing threats to native species and ecosystem functioning. One potential pathway for introductions is the commercial bait trade; unknowing or unconcerned anglers commonly release unused bait into aquatic systems. Previous surveillance efforts of this pathway relied on visual inspection of bait stocks in retail shops, which can be time and cost prohibitive and requires a trained individual that can rapidly and accurately identify cryptic species. Environmental DNA (eDNA) surveillance, a molecular tool that has been used for surveillance in aquatic environments, can be used to efficiently detect species at low abundances. We collected and analyzed 576 eDNA samples from 525 retail bait shops throughout the Laurentian Great Lake states. We used eDNA techniques to screen samples for multiple aquatic invasive species (AIS) that could be transported in the bait trade, including bighead (Hypophthalmichthys nobilis) and silver carp (H. molitrix), round goby (Neogobius melanostomus), tubenose goby (Proterorhinus marmoratus), Eurasian rudd (Scardinius erythrophthalmus), and goldfish (Carassius auratus). Twenty-seven samples were positive for at least one target species (4.7% of samples), and all target species were found at least once, except bighead carp. Despite current regulations, the bait trade remains a potential pathway for invasive species introductions in the Great Lakes region. Alterations to existing management strategies regarding the collection, transportation, and use of live bait are warranted, including new and updated regulations, to prevent future introductions of invasive species in the Great Lakes via the bait trade. © 2014 Society for Conservation Biology.

Assessing diet compositions of Lake Ontario predators using fatty acid profiles of prey fishes

Science.gov (United States)

Happell, Austin; Pattridge, Robert; Rinchard, Jacques; Walsh, Maureen

2017-01-01

Fatty acid profiles are used in food web studies to assess trophic interactions between predator and prey. The present study provides the first comprehensive fatty acid dataset for important prey and predator species in Lake Ontario. Three major prey fish (alewife, rainbow smelt, and round goby) were collected at three sites along the southern shore of Lake Ontario during the spring and fall of 2013, and predator species were collected in similar locations during the summer of 2013. Fatty acid compositions were compared among all prey species, all predator species, and information from both predator and prey was used to infer foraging differences among predators. Seasonal differences in fatty acids were found within each prey species studied. Differences among prey species were greater than any spatio-temporal differences detected within species. Fatty acids of predators revealed species-specific differences that matched known foraging habits. Chinook and Coho salmon, which are known to select alewife as their dominant prey item, had relatively little variation in fatty acid profiles. Conversely, brown trout, lake trout, yellow perch and esocids had highly variable fatty acid profiles and likely highly variable diet compositions. In general, our data suggested three dominant foraging patterns: 1) diet composed of nearly exclusively alewife for Chinook and Coho Salmon; 2) a mixed diet of alewife and round goby for brown and lake trout, and both rock and smallmouth bass; 3) a diet that is likely comprised of forage fishes other than those included in our study for northern pike and chain pickerel.

Seminal fluid enhances competitiveness of territorial males' sperm in a fish with alternative male reproductive tactics.

Science.gov (United States)

Poli, Federica; Locatello, Lisa; Rasotto, Maria B

2018-05-29

The most common adaptation to sperm competition in males is represented by an increase in the sperm number and/or quality released at mating, to raise their probability of egg fertilization. However, rapidly mounting evidence highlights that seminal fluid may directly influence the competitive fertilization success of a male by affecting either own and/or rival sperm performances. In the black goby, Gobius niger , an external fertilizer with guard-sneaker mating tactics and high sperm competition level, sneaker males' ejaculates contain less seminal fluid and more sperm, that are also of better quality, than those of territorial males. However, territorial males, gain a higher paternity success inside natural nests. Here, we ask whether the seminal fluid can contribute to territorial males' reproductive success by enhancing their sperm performances and/or by decreasing those of sneaker males. Using sperm and seminal fluid manipulation and in vitro fertilization tests, we found that own seminal fluid influences the velocity and fertilization ability of sperm only in territorial males, making them as faster as those of sneakers and with similar fertilization rate. Moreover, both sneaker and territorial males' sperm remain unaffected by the seminal fluid of rival males. Thus, black goby males respond to the different level of sperm competition faced by differently allocating in sperm and non-sperm components of the ejaculate, with sneakers primarily investing in sperm of intrinsic high quality and territorial males relying on the effect of seminal fluid to increase the lower intrinsic quality of their sperm. © 2018. Published by The Company of Biologists Ltd.

The diet of whiting Merlangius merlangus in the western Baltic Sea

DEFF Research Database (Denmark)

Ross, Stine Dalmann; Gislason, Henrik; Andersen, Niels Gerner

2016-01-01

The diet of whiting Merlangius merlangus in the western Baltic Sea was investigated and compared to the diet in the southern North Sea. Clupeids were important prey in both areas, but especially in the western Baltic Sea where they constituted up to 90% of the diet of larger individuals. Gobies......, brown shrimps and polychaetes were the main prey of juveniles in the western Baltic Sea, while a wider range of species were consumed in the North Sea. The shift to piscivory occurred at smaller sizes in the western Baltic Sea and the fish prey consumed was proportionately larger than in the southern...

Depletion rates of gastrointestinal content in common goby (Pomatoschistus microps (Kr.))

DEFF Research Database (Denmark)

Andersen, Niels Gerner

1984-01-01

Relatively complicated surgery is a necessity when implanting sensors internally in fish in order to measure physiological variables at specific locations. A surgical procedure from implanting transmitters with remote sensors into the body cavity of cod (Gadus morhua L.) is presented. The method ...

Geophysical survey of the proposed Tsenkher impact structure, Gobi Altai, Mongolia

Science.gov (United States)

Ormö, Jens; Gomez-Ortiz, David; Komatsu, Goro; Bayaraa, Togookhuu; Tserendug, Shoovdor

2010-03-01

We have performed forward magnetic and gravity modeling of data obtained during the 2007 expedition to the 3.7km in diameter, circular, Tsenkher structure, Mongolia, in order to evaluate the cause of its formation. Extensive occurrences of brecciated rocks, mainly in the form of an ejecta blanket outside the elevated rim of the structure, support an explosive origin (e.g., cosmic impact, explosive volcanism). The host rocks in the area are mainly weakly magnetic, silica-rich sandstones, and siltstones. A near absence of surface exposures of volcanic rocks makes any major volcanic structures (e.g., caldera) unlikely. Likewise, the magnetic models exclude any large, subsurface, intrusive body. This is supported by an 8mGal gravity low over the structure indicating a subsurface low density body. Instead, the best fit is achieved for a bowl-shaped structure with a slight central rise as expected for an impact crater of this size in mainly sedimentary target. The structure can be either root-less (i.e., impact crater) or rooted with a narrow feeder dyke with relatively higher magnetic susceptibility and density (i.e., volcanic maar crater). The geophysical signature, the solitary appearance, the predominantly sedimentary setting, and the comparably large size of the Tsenkher structure favor the impact crater alternative. However, until mineralogical/geochemical evidence for an impact is presented, the maar alternative remains plausible although exceptional as it would make the Tsenkher structure one of the largest in the world in an unusual setting for maar craters.

Investigations into the diet and feeding ecology of the bearded goby ...

African Journals Online (AJOL)

Given the importance of this species in recycling benthic carbon through the foodweb of the northern Benguela ecosystem, there is a need to describe and quantify the benthic food environment. Keywords: Benguela, benthic-pelagic coupling, ecosystem approach to fisheries, infauna, polychaetes, zooplankton

Predator diversity effects in an exotic freshwater food web.

Science.gov (United States)

Naddafi, Rahmat; Rudstam, Lars G

2013-01-01

Cascading trophic interactions are often defined as the indirect effects of a predator on primary producers through the effect of the predator on herbivores. These effects can be both direct through removal of herbivores [density-mediated indirect interactions (DMIIs)] or indirect through changes in the behavior of the herbivores [trait-mediated indirect interactions (TMIIs)]. How the relative importance of these two indirect interactions varies with predator diversity remains poorly understood. We tested the effect of predator diversity on both TMIIs and DMIIs on phytoplankton using two competitive invasive dreissenid mussel species (zebra mussel and quagga mussel) as the herbivores and combinations of one, two or all three species of the predators pumpkinseed sunfish, round goby, and rusty crayfish. Predators had either direct access to mussels and induced both TMII and DMII, or no direct access and induced only TMII through the presence of risk cues. In both sets of treatments, the predators induced a trophic cascade which resulted in more phytoplankton remaining with predators present than with only mussels present. The trophic cascade was weaker in three-predator and two-predator treatments than in one-predator treatments when predators had direct access to dreissenids (DMIIs and TMIIs). Crayfish had higher cascading effects on phytoplankton than both pumpkinseed and round goby. Increased predator diversity decreased the strength of DMIIs but had no effect on the strength of TMIIs. The strength of TMIIs was higher with zebra than quagga mussels. Our study suggests that inter-specific interference among predators in multi-species treatments weakens the consumptive cascading effects of predation on lower trophic levels whereas the importance of predator diversity on trait mediated effects depends on predator identity.

PENGARUH SISTEM PERGANTIAN AIR YANG BERBEDA PADA PEMELIHARAAN BENIH IKAN BETUTU (Oxyeleotris marmorata Blkr.

Directory of Open Access Journals (Sweden)

Imam Taufik

2016-12-01

Full Text Available Penelitian bertujuan untuk mengetahui sistem pergantian air yang paling baik pada pemeliharaan benih ikan betutu. Wadah penelitian: 12 unit bak kayu berlapis plastik (1,9m x 0,8m x 0,5m diisi air 500 L, ditempatkan dalam ruang terlindung dan dilengkapi dengan aerasi. Hewan uji: benih ikan betutu ukuran bobot 0,96±0,08 g/ekor, padat tebar 1 ekor/5 liter air, diberi pakan alami secara berlebih dengan waktu pemeliharaan selama 12 minggu. Perlakuan berupa perbedaan sistem pergantian air: (a resirkulasi, (b semi-statis, dan (c continous flow. Parameter yang diukur: sintasan, pertumbuhan, dan produktivitas benih ikan betutu serta sifat fisika-kimia air pemeliharaan. Hasil penelitian menunjukkan bahwa pergantian air dengan sistem resirkulasi memberikan sintasan yang paling baik terhadap benih ikan betutu (33,0% dibanding continous flow (28,3% dan berbeda nyata (P0,05 dengan nilai secara berturut-turut sebesar: 1,41%; 1,31%; dan 1,50%. The aim of this experiment is to obtain the information on survival rate and growth of sand goby fries. The experiment was conducted at research station CibalagungBogor. Twelve container of 1.9m x 0.8m x 0.5m were used in this experiment, each container was stocked with 1 fish/5L of sand goby fry with 0.96±0.08 gram weight. Three different water exchange were aplied i.e (a recirculation, (b semi static, and (c continous flow. Each treatment was done in three replicates. The result showed that the recirculation gave the best result on survival rate (33.0% compared with continous flow (28.3% and significantly different from semi static (21.3%.

Predator diversity effects in an exotic freshwater food web.

Directory of Open Access Journals (Sweden)

Rahmat Naddafi

Full Text Available Cascading trophic interactions are often defined as the indirect effects of a predator on primary producers through the effect of the predator on herbivores. These effects can be both direct through removal of herbivores [density-mediated indirect interactions (DMIIs] or indirect through changes in the behavior of the herbivores [trait-mediated indirect interactions (TMIIs]. How the relative importance of these two indirect interactions varies with predator diversity remains poorly understood. We tested the effect of predator diversity on both TMIIs and DMIIs on phytoplankton using two competitive invasive dreissenid mussel species (zebra mussel and quagga mussel as the herbivores and combinations of one, two or all three species of the predators pumpkinseed sunfish, round goby, and rusty crayfish. Predators had either direct access to mussels and induced both TMII and DMII, or no direct access and induced only TMII through the presence of risk cues. In both sets of treatments, the predators induced a trophic cascade which resulted in more phytoplankton remaining with predators present than with only mussels present. The trophic cascade was weaker in three-predator and two-predator treatments than in one-predator treatments when predators had direct access to dreissenids (DMIIs and TMIIs. Crayfish had higher cascading effects on phytoplankton than both pumpkinseed and round goby. Increased predator diversity decreased the strength of DMIIs but had no effect on the strength of TMIIs. The strength of TMIIs was higher with zebra than quagga mussels. Our study suggests that inter-specific interference among predators in multi-species treatments weakens the consumptive cascading effects of predation on lower trophic levels whereas the importance of predator diversity on trait mediated effects depends on predator identity.

Energy from the desert. Very large scale photovoltaic systems: socio-economic, financial, technical and environmental aspects. Executive summary

Energy Technology Data Exchange (ETDEWEB)

Kurokawa, K.; Ito, M.; Komoto, K.; Vleuten, P. van der; Faiman, D. (eds.)

2009-05-15

This executive summary report for the International Energy Agency (IEA) summarises the objectives and concepts of very large scale photovoltaic power generation (VLS-PV) systems and takes a look at the socio-economic, financial and technical aspects involved as well as the environmental impact of such systems. Potential benefits for desert communities, agricultural development and desalination of water are topics that are looked at. The potential of VLS-PV, its energy payback time and CO{sub 2} emission rates are discussed. Case studies for the Sahara and the Gobi Dessert areas are discussed. A VLS-PV roadmap is proposed and scenarios are discussed. Finally, conclusions are drawn and recommendations are made.

A theropod dinosaur embryo and the affinities of the flaming cliffs dinosaur eggs.

Science.gov (United States)

Norell, M A; Clark, J M; Demberelyin, D; Rhinchen, B; Chiappe, L M; Davidson, A R; McKenna, M C; Altangerel, P; Novacek, M J

1994-11-04

An embryonic skeleton of a nonavian theropod dinosaur was found preserved in an egg from Upper Cretaceous rocks in the Gobi Desert of Mongolia. Cranial features identify the embryo as a member of Oviraptoridae. Two embryo-sized skulls of dromaeosaurids, similar to that of Velociraptor, were also recovered in the nest. The eggshell microstructure is similar to that of ratite birds and is of a type common in the Djadokhta Formation at the Flaming Cliffs (Bayn Dzak). Discovery of a nest of such eggs at the Flaming Cliffs in 1923, beneath the Oviraptor philoceratops holotype, suggests that this dinosaur may have been a brooding adult.

Application effect of TEM sounding survey on prospecting and target area selection of sandstone-type uranium deposits

International Nuclear Information System (INIS)

He Jianguo; Liang Shanming; Zhao Cuiping

2006-01-01

Based on the results of transient electromagnetic (TEM) sounding survey during recent years regional geological reconnaissance with drilling (1:250000), the application effect of TEM sounding survey during regional reconnaissance is summarized in this paper. It is suggested that the data of TEM sounding are useful in judging hydrodynamic conditions of groundwater and determining favorable areas for uranium ore-formation; TEM sounding in large areas may be proper for prospecting in gobi-desert areas and be beneficial for regional reconnaissance and target area selection, and may reduce the target area and provide basis for further drilling program. It is of popularized significance in the prospecting for sandstone-type uranium deposits. (authors)

A hydrodynamic model of nearshore waves and wave-induced currents

Directory of Open Access Journals (Sweden)

Ahmed Khaled Seif

2011-09-01

Full Text Available In This study develops a quasi-three dimensional numerical model of wave driven coastal currents with accounting the effects of the wave-current interaction and the surface rollers. In the wave model, the current effects on wave breaking and energy dissipation are taken into account as well as the wave diffraction effect. The surface roller associated with wave breaking was modeled based on a modification of the equations by Dally and Brown (1995 and Larson and Kraus (2002. Furthermore, the quasi-three dimensional model, which based on Navier-Stokes equations, was modified in association with the surface roller effect, and solved using frictional step method. The model was validated by data sets obtained during experiments on the Large Scale Sediment Transport Facility (LSTF basin and the Hazaki Oceanographical Research Station (HORS. Then, a model test against detached breakwater was carried out to investigate the performance of the model around coastal structures. Finally, the model was applied to Akasaki port to verify the hydrodynamics around coastal structures. Good agreements between computations and measurements were obtained with regard to the cross-shore variation in waves and currents in nearshore and surf zone.

Carcass feeding as a cryptic foraging mode in round goby Neogobius melanostomus

Czech Academy of Sciences Publication Activity Database

Polačik, Matej; Jurajda, Pavel; Blažek, Radim; Janáč, Michal

2015-01-01

Roč. 87, č. 1 (2015), s. 194-199 ISSN 0022-1112 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : diet * food web * necrophagy * trophic ecology Subject RIV: EG - Zoology Impact factor: 1.246, year: 2015

PENGARUH PERBEDAAN SUHU AIR PADA PEMELIHARAAN BENIH IKAN BETUTU (Oxyeleotris marmorata Blkr DENGAN SISTEM RESIRKULASI

Directory of Open Access Journals (Sweden)

Imam Taufik

2016-11-01

Full Text Available Penelitian bertujuan untuk menentukan suhu air yang optimal pada pemeliharaan benih ikan betutu dengan sistem resirkulasi air. Wadah penelitian: 16 unit bak kayu berlapis plastik (1,5 m x 0,7 m x 0,5 m diisi air 300 L yang masing-masing menggunakan bak filter, ditempatkan dalam ruang terlindung dan dilengkapi dengan aerasi. Hewan uji: benih ikan betutu ukuran fingerling (0,65±0,118 g/ekor, padat tebar 1 ekor/5 liter air, diberi makanan alami berupa cacing dan ikan seribu secara berlebih, dengan waktu pemeliharaan 12 minggu. Perlakuan berupa perbedaan suhu air, yaitu: (a 26oC; (b 29oC; (c 32oC; dan (d 24oC–28oC. Parameter yang diukur: sintasan, pertumbuhan, dan produktivitas benih ikan betutu serta sifat fisika-kimia air pemeliharaan. Hasil pene-litian menunjukkan bahwa suhu air paling baik adalah 29oC dan 32oC dan secara nyata (P<0,05 berpengaruh terhadap sintasan, pertumbuhan, dan produktivitas ikan betutu. The objective of the research was know the optimum water temperature in rearing of sand goby fingerlings. Sixteen containers of 1.5 m x 0.7 m x 0.5 m in size were used in this experiment. Each container was stocked with 1 fish/5 L. Average fish weight of 0.65±0.118 gram. Four different water temperatures were applied i.e: (a 26oC; (b 29oC; (c 32oC; and (d 24oC-28oC. The result showed that the water temperature of 29oC and 32oC gave the best result on survival rate, growth rate, and productifity of sand goby.

Effects of season, sex and body size on the feeding ecology of turtle-headed sea snakes ( Emydocephalus annulatus) on IndoPacific inshore coral reefs

Science.gov (United States)

Goiran, C.; Dubey, S.; Shine, R.

2013-06-01

In terrestrial snakes, many cases of intraspecific shifts in dietary habits as a function of predator sex and body size are driven by gape limitation and hence are most common in species that feed on relatively large prey and exhibit a wide body-size range. Our data on sea snakes reveal an alternative mechanism for intraspecific niche partitioning, based on sex-specific seasonal anorexia induced by reproductive activities. Turtle-headed sea snakes ( Emydocephalus annulatus) on coral reefs in the New Caledonian Lagoon feed entirely on the eggs of demersal-spawning fishes. DNA sequence data (cytochrome b gene) on eggs that we palpated from stomachs of 37 snakes showed that despite this ontogenetic stage specialization, the prey comes from a taxonomically diverse array of species including damselfish (41 % of samples, at least 5 species), blennies (41 %, 4 species) and gobies (19 %, 5 species). The composition of snake diets shifted seasonally (with damselfish dominating in winter but not summer), presumably reflecting seasonality of fish reproduction. That seasonal shift affects male and female snakes differently, because reproduction is incompatible with foraging. Adult female sea snakes ceased feeding when they became heavily distended with developing embryos in late summer, and males ceased feeding while they were mate searching in winter. The sex divergence in foraging habits may be amplified by sexual size dimorphism; females grow larger than males, and larger snakes (of both sexes) feed more on damselfish (which often lay their eggs in exposed sites) than on blennies and gobies (whose eggs are hidden within narrow crevices). Specific features of reproductive biology of coral reef fish (seasonality and nest type) have generated intraspecific niche partitioning in these sea snakes, by mechanisms different from those that apply to terrestrial snakes.

Palinspastic reconstruction and geological evolution of Permian residual marine basins bordering China and Mongolia

Directory of Open Access Journals (Sweden)

Gen-Yao Wu

2014-04-01

Full Text Available One main feature of the tectono-paleogeographic evolution of the southern branch of the Paleo-Asian Ocean was that there developed residual marine basins in former backarc/forearc regions after the disappearance of oceanic crust. The paper illustrates the viewpoint taking the evolution of Dalandzadgad and Solonker oceanic basins as examples. The Dalandzadgad ocean subducted southwards during the Silurian-Devonian, created an intra-oceanic arc and a backarc basin in southern Mongolia. In addition, a continent marginal arc formed along the national boundary between China and Mongolia, the south of which was a backarc basin. The oceanic basin closed and arc–arc (continent collision occurred during the early Early Permian, followed by two residual marine basins developing in the former backarc regions, named the South Gobi Basin in southern Mongolia and the Guaizihu Basin in western Inner Mongolia. The Solonker ocean subducted southwards and finally disappeared during the early Middle Permian. Afterwards, two residual marine basins occurred in northern China, the Zhesi Basin being situated in the former backarc region and the Wujiatun Basin in the former forearc region. The late Middle Permian was the most optimum period for the developing residual marine basins, when they covered a vast area. The basin evolution differentiated during the early Late Permian, with a general trend of uplift in the east and of subsidence in the west. The Upper Permian in the South Gobi Basin was characterized by coal-bearing strata hosting economically valuable coal fields. A transgression invaded westwards and the Chandmani-Bayanleg Basin was created in southwest Mongolia during the middle-late stage of the Late Permian. Correspondingly, the coal formation entered a flourishing time, with thick coal beds and sedimentary interbeds. All of these basins, namely, both the marine and nonmarine residual basins, reversed and closed by the end of Permian.

Development of standard weight equations for Caribbean and Gulf of Mexico amphidromous fishes

Science.gov (United States)

Cooney, Patrick B.; Kwak, Thomas J.

2010-01-01

We collected and compiled length and weight information from four countries and one commonwealth to develop standard weight (Ws) equations for three amphidromous fish species native to the Caribbean and Gulf of Mexico regions: mountain mullet Agonostomus monticola (N = 9,768 individuals, 52 populations), river goby Awaous banana (N = 1,847 individuals, 62 populations), and bigmouth sleeper Gobiomorus dormitor (N = 2,983 individuals, 53 populations). Linear and quadratic Ws equations for three quartiles (25%, median, 75%) are presented for these three species. The length-weight relationship from eight lentic bigmouth sleeper populations was significantly different from that of lotic populations, reflecting higher weights of juvenile fish (sport fisheries and allow ecological assessment based on fish condition.

Monitoring an alien invasion: DNA barcoding and the identification of lionfish and their prey on coral reefs of the Mexican Caribbean.

Science.gov (United States)

Valdez-Moreno, Martha; Quintal-Lizama, Carolina; Gómez-Lozano, Ricardo; García-Rivas, María Del Carmen

2012-01-01

In the Mexican Caribbean, the exotic lionfish Pterois volitans has become a species of great concern because of their predatory habits and rapid expansion onto the Mesoamerican coral reef, the second largest continuous reef system in the world. This is the first report of DNA identification of stomach contents of lionfish using the barcode of life reference database (BOLD). We confirm with barcoding that only Pterois volitans is apparently present in the Mexican Caribbean. We analyzed the stomach contents of 157 specimens of P. volitans from various locations in the region. Based on DNA matches in the Barcode of Life Database (BOLD) and GenBank, we identified fishes from five orders, 14 families, 22 genera and 34 species in the stomach contents. The families with the most species represented were Gobiidae and Apogonidae. Some prey taxa are commercially important species. Seven species were new records for the Mexican Caribbean: Apogon mosavi, Coryphopterus venezuelae, C. thrix, C. tortugae, Lythrypnus minimus, Starksia langi and S. ocellata. DNA matches, as well as the presence of intact lionfish in the stomach contents, indicate some degree of cannibalism, a behavior confirmed in this species by the first time. We obtained 45 distinct crustacean prey sequences, from which only 20 taxa could be identified from the BOLD and GenBank databases. The matches were primarily to Decapoda but only a single taxon could be identified to the species level, Euphausia americana. This technique proved to be an efficient and useful method, especially since prey species could be identified from partially-digested remains. The primary limitation is the lack of comprehensive coverage of potential prey species in the region in the BOLD and GenBank databases, especially among invertebrates.

Monitoring an alien invasion: DNA barcoding and the identification of lionfish and their prey on coral reefs of the Mexican Caribbean.

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Martha Valdez-Moreno

Full Text Available BACKGROUND: In the Mexican Caribbean, the exotic lionfish Pterois volitans has become a species of great concern because of their predatory habits and rapid expansion onto the Mesoamerican coral reef, the second largest continuous reef system in the world. This is the first report of DNA identification of stomach contents of lionfish using the barcode of life reference database (BOLD. METHODOLOGY/PRINCIPAL FINDINGS: We confirm with barcoding that only Pterois volitans is apparently present in the Mexican Caribbean. We analyzed the stomach contents of 157 specimens of P. volitans from various locations in the region. Based on DNA matches in the Barcode of Life Database (BOLD and GenBank, we identified fishes from five orders, 14 families, 22 genera and 34 species in the stomach contents. The families with the most species represented were Gobiidae and Apogonidae. Some prey taxa are commercially important species. Seven species were new records for the Mexican Caribbean: Apogon mosavi, Coryphopterus venezuelae, C. thrix, C. tortugae, Lythrypnus minimus, Starksia langi and S. ocellata. DNA matches, as well as the presence of intact lionfish in the stomach contents, indicate some degree of cannibalism, a behavior confirmed in this species by the first time. We obtained 45 distinct crustacean prey sequences, from which only 20 taxa could be identified from the BOLD and GenBank databases. The matches were primarily to Decapoda but only a single taxon could be identified to the species level, Euphausia americana. CONCLUSIONS/SIGNIFICANCE: This technique proved to be an efficient and useful method, especially since prey species could be identified from partially-digested remains. The primary limitation is the lack of comprehensive coverage of potential prey species in the region in the BOLD and GenBank databases, especially among invertebrates.

Monitoring an Alien Invasion: DNA Barcoding and the Identification of Lionfish and Their Prey on Coral Reefs of the Mexican Caribbean

Science.gov (United States)

Valdez-Moreno, Martha; Quintal-Lizama, Carolina; Gómez-Lozano, Ricardo; García-Rivas, María del Carmen

2012-01-01

Background In the Mexican Caribbean, the exotic lionfish Pterois volitans has become a species of great concern because of their predatory habits and rapid expansion onto the Mesoamerican coral reef, the second largest continuous reef system in the world. This is the first report of DNA identification of stomach contents of lionfish using the barcode of life reference database (BOLD). Methodology/Principal Findings We confirm with barcoding that only Pterois volitans is apparently present in the Mexican Caribbean. We analyzed the stomach contents of 157 specimens of P. volitans from various locations in the region. Based on DNA matches in the Barcode of Life Database (BOLD) and GenBank, we identified fishes from five orders, 14 families, 22 genera and 34 species in the stomach contents. The families with the most species represented were Gobiidae and Apogonidae. Some prey taxa are commercially important species. Seven species were new records for the Mexican Caribbean: Apogon mosavi, Coryphopterus venezuelae, C. thrix, C. tortugae, Lythrypnus minimus, Starksia langi and S. ocellata. DNA matches, as well as the presence of intact lionfish in the stomach contents, indicate some degree of cannibalism, a behavior confirmed in this species by the first time. We obtained 45 distinct crustacean prey sequences, from which only 20 taxa could be identified from the BOLD and GenBank databases. The matches were primarily to Decapoda but only a single taxon could be identified to the species level, Euphausia americana. Conclusions/Significance This technique proved to be an efficient and useful method, especially since prey species could be identified from partially-digested remains. The primary limitation is the lack of comprehensive coverage of potential prey species in the region in the BOLD and GenBank databases, especially among invertebrates. PMID:22675470

Study on atmosphere pollution by PIXE analysis combining with statistical method

International Nuclear Information System (INIS)

Zhu Guanghua

1994-06-01

Atmospheric aerosol samples were collected using an 8-stage cascade impactor or an automatic time sequence step sampler at Jomo Langma, Zhangye at the edge of Gobi Desert and Beijing. Element concentration were analyzed by PIXE (proton induced X-ray emission) technique. The data were analyzed by APCA (absolute principal component analysis) to determine the principal components. The sources and contribution to the aerosol in the above three regions were discussed. The result shows that the PIXE has high sensitivity, multi-element capability, high speed and non-destruction advantages. APCA analytical method can effectively determine the aerosol components in urban area, and it also can distinguish between local components and remote components in the area far from the pollution resources

Clicking in a killer whale habitat: narrow-band, high-frequency biosonar clicks of harbour porpoise (Phocoena phocoena and Dall's porpoise (Phocoenoides dalli.

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Line A Kyhn

Full Text Available Odontocetes produce a range of different echolocation clicks but four groups in different families have converged on producing the same stereotyped narrow band high frequency (NBHF click. In microchiropteran bats, sympatric species have evolved the use of different acoustic niches and subtly different echolocation signals to avoid competition among species. In this study, we examined whether similar adaptations are at play among sympatric porpoise species that use NBHF echolocation clicks. We used a six-element hydrophone array to record harbour and Dall's porpoises in British Columbia (BC, Canada, and harbour porpoises in Denmark. The click source properties of all porpoise groups were remarkably similar and had an average directivity index of 25 dB. Yet there was a small, but consistent and significant 4 kHz difference in centroid frequency between sympatric Dall's (137±3 kHz and Canadian harbour porpoises (141±2 kHz. Danish harbour porpoise clicks (136±3 kHz were more similar to Dall's porpoise than to their conspecifics in Canada. We suggest that the spectral differences in echolocation clicks between the sympatric porpoises are consistent with evolution of a prezygotic isolating barrier (i.e., character displacement to avoid hybridization of sympatric species. In practical terms, these spectral differences have immediate application to passive acoustic monitoring.

Habitat selection by a focal predator (Canis lupus) in a multiprey ecosystem of the northern Rockies

Science.gov (United States)

Milakovic, B.; Parker, K.L.; Gustine, D.D.; Lay, R.J.; Walker, A.B.D.; Gillingham, M.P.

2011-01-01

Large predators respond to land cover and physiography that maximize the likelihood of encountering prey. Using locations from global positioning system-collared wolves (Canis lupus), we examined whether land cover, vegetation productivity or change, or habitat-selection value for ungulate prey species themselves most influenced patterns of selection by wolves in a large, intact multiprey system of northern British Columbia. Selection models based on land cover, in combination with topographical features, consistently outperformed models based on indexes of vegetation quantity and quality (using normalized difference vegetation index) or on selection value to prey species (moose [Alces americanus], elk [Cervus elaphus], woodland caribou [Rangifer tarandus], and Stone's sheep [Ovis dalli stonei]). Wolves generally selected for shrub communities and high diversity of cover across seasons and avoided conifer stands and non-vegetated areas and west aspects year-round. Seasonal selection strategies were not always reflected in use patterns, which showed highest frequency of use in riparian, shrub, and conifer classes. Patterns of use and selection for individual wolf packs did not always conform to global models, and appeared related to the distribution of land cover and terrain within respective home ranges. Our findings corroborate the biological linkages between wolves and their habitat related to ease of movement and potential prey associations. ?? American 2011 Society of Mammalogists.

Importância da reabsorção do ferro da hemorragia intestinal provocada pela ação dos vermes na progressão da anemia The importance of iron reabsorption in intestinal hemorrhage caused by worms in the course of anemia

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Victorio Maspes

1979-12-01

Full Text Available Foram estudados 10 doentes, portadores de anemia ancilostomótica e de grande parasitose. Foram determinados alguns parâmetros hematológicos como dosagem de hemoglobina, contagem de hemácias, hematócrito, volume corpuscular médio, hemoglobina corpuscular média, ferro sérico e siderofilina. Foram estudados o volume da perda de sangue intestinal, o ferro perdido nesta hemorragia e eliminado nas fezes, e o ferro reaborvido da hemorragia intestinal. Conclui-se que a reabsorção do ferro da hemoglobina por dia no tubo digestivo é de suma importância no retardamento da instalação da anemia ferropriva, causada pela parasitose ancilostomótica.Ten patients presenting ancylostomotic anemia and a high rate of parasitosis were submitted to several hematologic determinations: hemoglobin level, erythrocyte count, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, serum iron level, and transferrin. In addition, measurements were made of the blood volume lost by intestinal bleeding, of iron loss through hemorrhage and in feus, and of iron reabsorption from intestinal bleeding. The main reason for the late appearance of iron deficiency anemia in ancylostomiasis is the high degree of dally iron absorption in the digestive tract, originating from hemoglobin breakdown.

Seasonal and interannual effects of hypoxia on fish habitat quality in central Lake Erie

Science.gov (United States)

Arend, Kristin K.; Beletsky, Dmitry; DePinto, Joseph; Ludsin, Stuart A.; Roberts, James J.; Rucinski, Daniel K.; Scavia, Donald; Schwab, David J.; Höök, Tomas O.

2011-01-01

1. Hypoxia occurs seasonally in many stratified coastal marine and freshwater ecosystems when bottom dissolved oxygen (DO) concentrations are depleted below 2–3 mg O2 L-1. 2. We evaluated the effects of hypoxia on fish habitat quality in the central basin of Lake Erie from 1987 to 2005, using bioenergetic growth rate potential (GRP) as a proxy for habitat quality. We compared the effect of hypoxia on habitat quality of (i) rainbow smelt, Osmerus mordax mordax Mitchill (young-of-year, YOY, and adult), a cold-water planktivore, (ii) emerald shiner, Notropis atherinoides Rafinesque (adult), a warm-water planktivore, (iii) yellow perch, Perca flavescens Mitchill (YOY and adult), a cool-water benthopelagic omnivore and (iv) round goby Neogobius melanostomus Pallas (adult) a eurythermal benthivore. Annual thermal and DO profiles were generated from 1D thermal and DO hydrodynamics models developed for Lake Erie’s central basin. 3. Hypoxia occurred annually, typically from mid-July to mid-October, which spatially and temporally overlaps with otherwise high benthic habitat quality. Hypoxia reduced the habitat quality across fish species and life stages, but the magnitude of the reduction varied both among and within species because of the differences in tolerance to low DO levels and warm-water temperatures. 4. Across years, trends in habitat quality mirrored trends in phosphorus concentration and water column oxygen demand in central Lake Erie. The per cent reduction in habitat quality owing to hypoxia was greatest for adult rainbow smelt and round goby (mean: -35%), followed by adult emerald shiner (mean: -12%), YOY rainbow smelt (mean: -10%) and YOY and adult yellow perch (mean: -8.5%). 5. Our results highlight the importance of differential spatiotemporally interactive effects of DO and temperature on relative fish habitat quality and quantity. These effects have the potential to influence the performance of individual fish species as well as population dynamics

Age at maturity of Mediterranean marine fishes

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A. C. TSIKLIRAS

2014-07-01

Full Text Available In this review we collected data on the age at maturity (tm and maximum reported age (tmax for 235 stocks of Mediterranean marine fishes, belonging to 82 species, 37 families, 12 orders and 2 classes (Actinopterygii and Elasmobranchii. Among Actinopterygii (mean tm ± SD = 2.20 ± 1.43 y, n = 215, tm ranged from 0.3 y, for the common goby Pomatoschistus microps, to 12 y, for dusky grouper Epinephelus marginatus, while among Elasmobranchii (mean tm ± SD = 5.94 ± 2.47 y, n = 20, tm ranged between 2.7 y, for brown ray Raja miraletus, and 12 y for picked dogfish Squalus acanthias. Overall, the tmax ranged between 1 y, for transparent goby Aphia minuta, and 70 y, for wreckfish Polyprion americanus. The mean tmax of Actinopterygii (tmax ± SD = 10.14 ± 9.42 y was lower than that of Elasmobranchii (tmax ± SD = 14.05 ± 8.47 y. The tm exhibited a strong positive linear relation with tmax for both Actinopterygii (logtm = 0.58 ´ logtmax – 0.25, r2 = 0.51, P < 0.001 and Elasmobranchii (logtm = 0.67 ´ logtmax – 0.006, r2 = 0.51, P = 0.007. The mean tm/tmax did not differ significantly with sex within Actinopterygii (ANOVA: F = 0.27, P = 0.60, n = 90; females: mean ± SD = 0.276 ± 0.143; males: mean ± SD = 0.265 ± 0.138 and Elasmobranchii (ANOVA: F = 1.44, P = 0.25, n = 10; females: mean ± SD = 0.499 ± 0.166; males: mean ± SD = 0.418 ± 0.133. Finally, the dimensionless ratio tm/tmax was significantly lower (ANOVA: F = 31.04, P < 0.001 for Actinopterygii (mean ± SD = 0.270 ± 0.135, n = 180 than for Elasmobranchii, (mean ± SD = 0.458 ± 0.152, n = 20, when stocks with combined sexes were excluded from the analysis.

Diurnal and seasonal variations in carbon dioxide exchange in ecosystems in the Zhangye oasis area, Northwest China.

Science.gov (United States)

Zhang, Lei; Sun, Rui; Xu, Ziwei; Qiao, Chen; Jiang, Guoqing

2015-01-01

Quantifying carbon dioxide exchange and understanding the response of key environmental factors in various ecosystems are critical to understanding regional carbon budgets and ecosystem behaviors. For this study, CO2 fluxes were measured in a variety of ecosystems with an eddy covariance observation matrix between June 2012 and September 2012 in the Zhangye oasis area of Northwest China. The results show distinct diurnal variations in the CO2 fluxes in vegetable field, orchard, wetland, and maize cropland. Diurnal variations of CO2 fluxes were not obvious, and their values approached zero in the sandy desert, desert steppe, and Gobi ecosystems. Additionally, daily variations in the Gross Primary Production (GPP), Ecosystem Respiration (Reco) and Net Ecosystem Exchange (NEE) were not obvious in the sandy desert, desert steppe, and Gobi ecosystems. In contrast, the distributions of the GPP, Reco, and NEE show significant daily variations, that are closely related to the development of vegetation in the maize, wetland, orchard, and vegetable field ecosystems. All of the ecosystems are characterized by their carbon absorption during the observation period. The ability to absorb CO2 differed significantly among the tested ecosystems. We also used the Michaelis-Menten equation and exponential curve fitting methods to analyze the impact of Photosynthetically Active Radiation (PAR) on the daytime CO2 flux and impact of air temperature on Reco at night. The results show that PAR is the dominant factor in controlling photosynthesis with limited solar radiation, and daytime CO2 assimilation increases rapidly with PAR. Additionally, the carbon assimilation rate was found to increase slowly with high solar radiation. The light response parameters changed with each growth stage for all of the vegetation types, and higher light response values were observed during months or stages when the plants grew quickly. Light saturation points are different for different species. Nighttime

Diurnal and seasonal variations in carbon dioxide exchange in ecosystems in the Zhangye oasis area, Northwest China.

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Lei Zhang

Full Text Available Quantifying carbon dioxide exchange and understanding the response of key environmental factors in various ecosystems are critical to understanding regional carbon budgets and ecosystem behaviors. For this study, CO2 fluxes were measured in a variety of ecosystems with an eddy covariance observation matrix between June 2012 and September 2012 in the Zhangye oasis area of Northwest China. The results show distinct diurnal variations in the CO2 fluxes in vegetable field, orchard, wetland, and maize cropland. Diurnal variations of CO2 fluxes were not obvious, and their values approached zero in the sandy desert, desert steppe, and Gobi ecosystems. Additionally, daily variations in the Gross Primary Production (GPP, Ecosystem Respiration (Reco and Net Ecosystem Exchange (NEE were not obvious in the sandy desert, desert steppe, and Gobi ecosystems. In contrast, the distributions of the GPP, Reco, and NEE show significant daily variations, that are closely related to the development of vegetation in the maize, wetland, orchard, and vegetable field ecosystems. All of the ecosystems are characterized by their carbon absorption during the observation period. The ability to absorb CO2 differed significantly among the tested ecosystems. We also used the Michaelis-Menten equation and exponential curve fitting methods to analyze the impact of Photosynthetically Active Radiation (PAR on the daytime CO2 flux and impact of air temperature on Reco at night. The results show that PAR is the dominant factor in controlling photosynthesis with limited solar radiation, and daytime CO2 assimilation increases rapidly with PAR. Additionally, the carbon assimilation rate was found to increase slowly with high solar radiation. The light response parameters changed with each growth stage for all of the vegetation types, and higher light response values were observed during months or stages when the plants grew quickly. Light saturation points are different for different

Fluctuating asymmetry in evaluating the developmental instability of Glossogobius giuris (Hamilton, 1822 from Lake Mainit, Surigao del Norte, Philippines

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C.C.D.Joseph

2016-06-01

Full Text Available This study was conducted to assess the status of Lake Mainit by using fluctuating asymmetry in the populations of Glossogobius giuris. A total of 200 G. giuris was collected with 100 per sex. All the samples were placed in a flat styrofoam for the pinning of its fins to make it wider and to clearly see the samples point of origin for the land-marking process. 10% Formalin was applied in all the fins of the fish samples to make it hardened using a small brush. Twenty (20 landmarks were used to analyze the body shape of the fish. Several studies proved that FA can be used to directly assess water quality and the overall status of the ecosystem. Using thin-plate spline (TPS series, landmark analyses were obtained and subjected to Symmetry and Asymmetry in Geometric Data (SAGE software. Results in Procrustes ANOVA showed that individual symmetry showed a highly significant difference (P = 0.00 as well as Sides (Directional Asymmetry and Interaction (Fluctuating Asymmetry in the study area. All the samples showed FA in both sexes. The results of Principal Component Scores displayed a higher percentage in female (69.2797% than male (63.9214% from Lake Mainit. Variations are almost found in all the body part of the goby in female and male gobies except for anterior insertion of second dorsal fin and superior margin of the preoperculum. Females have a higher fluctuating asymmetry than in males. Females spawn and males protect the eggs from any predators. In this case, females are more susceptible to stress because they have to forage in order to compensate the energy used up during spawning. Males are less susceptible because they usually stay on the nesting ground, and don't have to cover far distances in finding food. This study validates the use of FA in determining the status of the fishes caught connecting to what the status of the environment is based on the result.

Model development of dust emission and heterogeneous chemistry within the Community Multiscale Air Quality modeling system and its application over East Asia

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X. Dong

2016-07-01

Full Text Available The Community Multiscale Air Quality (CMAQ model has been further developed in terms of simulating natural wind-blown dust in this study, with a series of modifications aimed at improving the model's capability to predict the emission, transport, and chemical reactions of dust. The default parameterization of initial threshold friction velocity constants are revised to correct the double counting of the impact of soil moisture in CMAQ by the reanalysis of field experiment data; source-dependent speciation profiles for dust emission are derived based on local measurements for the Gobi and Taklamakan deserts in East Asia; and dust heterogeneous chemistry is also implemented. The improved dust module in the CMAQ is applied over East Asia for March and April from 2006 to 2010. The model evaluation result shows that the simulation bias of PM10 and aerosol optical depth (AOD is reduced, respectively, from −55.42 and −31.97 % by the original CMAQ to −16.05 and −22.1 % by the revised CMAQ. Comparison with observations at the nearby Gobi stations of Duolun and Yulin indicates that applying a source-dependent profile helps reduce simulation bias for trace metals. Implementing heterogeneous chemistry also results in better agreement with observations for sulfur dioxide (SO2, sulfate (SO42−, nitric acid (HNO3, nitrous oxides (NOx, and nitrate (NO3−. The investigation of a severe dust storm episode from 19 to 21 March 2010 suggests that the revised CMAQ is capable of capturing the spatial distribution and temporal variation of dust. The model evaluation also indicates potential uncertainty within the excessive soil moisture used by meteorological simulation. The mass contribution of fine-mode particles in dust emission may be underestimated by 50 %. The revised CMAQ model provides a useful tool for future studies to investigate the emission, transport, and impact of wind-blown dust over East Asia and elsewhere.

Do Community-based Institutions Build Resilience to Climate Change in Mongolia?

Science.gov (United States)

Fernandez-Gimenez, M.

2012-12-01

Climate change impacts are inherently local, yet relatively little is known about the role of local people and institutions in adapting to climate change. Mongolia has experienced one of the strongest warming trends on Earth over the past 40 years, associated declines in streamflow, and increases in the frequency of extreme winter weather events. Environmental changes are compounded by rapid political, economic and social transformations beginning in 1990. We investigate the complex interactions of social, ecological and climate changes across multiple levels from local to regional to national. We hypothesize that community-based institutions increase resilience by strengthening self-regulating feedbacks between social and ecological systems through development and enforcement of formal management rules, implementation of innovative management practices, strengthening of social networks and information exchange within and across levels of social organization, and enhanced monitoring. These result in better ecological and socio-economic conditions and greater adaptive capacity in areas under formal community-based management compared to adjacent areas without formal community management institutions. Evaluation of this hypothesis involves integrated collection and analysis of quantitative and qualitative ecological, social and hydro-climatic data at household, community and regional levels of spatial and social organization. Here, we present preliminary results evaluating these hypotheses from 10 counties (soum) in 3 provinces (aimag) in the Gobi desert-steppe of southern Mongolia based on household-level social data and plot-level ecological data representing. Our initial findings support the hypothesis that community-based institutions are associated with greater household adaptive capacity and healthier pasture ecological conditions, characterized by greater perennial vegetation cover and biomass, especially in the functional group most important for livestock

Evaluating dispersal potential of an invasive fish by the use of aerobic scope and osmoregulation capacity.

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Jane W Behrens

Full Text Available Non-indigenous species (NIS can impact marine biodiversity and ecosystem structure and function. Once introduced into a new region, secondary dispersal is limited by the physiology of the organism in relation to the ambient environment and by complex interactions between a suite of ecological factors such as presence of predators, competitors, and parasites. Early prediction of dispersal potential and future 'area of impact' is challenging, but also a great asset in taking appropriate management actions. Aerobic scope (AS in fish has been linked to various fitness-related parameters, and may be valuable in determining dispersal potential of aquatic invasive species in novel environments. Round goby, Neogobius melanostomus, one of the most wide-ranging invasive fish species in Europe and North America, currently thrives in brackish and fresh water, but its ability to survive in high salinity waters is unknown to date. We show that AS in round goby is reduced by 30% and blood plasma osmolality increased (indicating reduced capacity for osmoregulation at salinities approaching oceanic conditions, following slow ramping (5 PSU per week and subsequent long-term acclimation to salinities ranging between 0 and 30 PSU (8 days at final treatment salinities before blood plasma osmolality measurements, 12-20 additional days before respirometry. Survival was also reduced at the highest salinities yet a significant proportion (61% of the fish survived at 30 PSU. Reduced physiological performance at the highest salinities may affect growth and competitive ability under oceanic conditions, but to what extent reduced AS and osmoregulatory capacity will slow the current 30 km year-1 rate of advance of the species through the steep salinity gradient from the brackish Baltic Sea and into the oceanic North Sea remains speculative. An unintended natural experiment is in progress to test whether the rate of advance slows down. At the current rate of advance the

Small‐scale distribution of fish in offshore windfarms

DEFF Research Database (Denmark)

Hansen, Kamilla Sande; Stenberg, Claus; Møller, Peter Rask

2012-01-01

Knowledge about small‐scale distribution of fish around turbines in offshore windfarms (OWF) remains relatively scarce. In the present study we used underwater video camera installations to access abundance of fish at 0, 25, and 50 m around the turbine foundations in Middelgrund and Lillgrund OWFs...... in Øresund between Denmark and Sweden in the period August–November 2011. Fish fauna in both localities were dominated in terms of numbers by two‐spotted gobies (Gobiusculus flavescens). Average number of fish observed per hour was a factor 100 higher at Lillgrund and a factor of 2 higher at Middelgrund at 0...... on fish fauna compared to OWFs in areas with heterogeneous sediment. Furthermore, the effect of OWFs on fish appears to be of a much smaller scale than previously thought...

Compression of FASTQ and SAM format sequencing data.

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James K Bonfield

Full Text Available Storage and transmission of the data produced by modern DNA sequencing instruments has become a major concern, which prompted the Pistoia Alliance to pose the SequenceSqueeze contest for compression of FASTQ files. We present several compression entries from the competition, Fastqz and Samcomp/Fqzcomp, including the winning entry. These are compared against existing algorithms for both reference based compression (CRAM, Goby and non-reference based compression (DSRC, BAM and other recently published competition entries (Quip, SCALCE. The tools are shown to be the new Pareto frontier for FASTQ compression, offering state of the art ratios at affordable CPU costs. All programs are freely available on SourceForge. Fastqz: https://sourceforge.net/projects/fastqz/, fqzcomp: https://sourceforge.net/projects/fqzcomp/, and samcomp: https://sourceforge.net/projects/samcomp/.

Temporal effects on host-parasite associations in four naturalized goby species living in sympatry

Czech Academy of Sciences Publication Activity Database

Ondračková, Markéta; Valová, Zdenka; Hudcová, Iveta; Michálková, Veronika; Šimková, A.; Borcherding, J.; Jurajda, Pavel

2015-01-01

Roč. 746, č. 1 (2015), s. 233-243 ISSN 0018-8158 R&D Projects: GA ČR(CZ) GAP505/12/2569 Institutional support: RVO:68081766 Keywords : Fish * Gobiidae * Non-native species * Parasite * Rhine Subject RIV: EG - Zoology Impact factor: 2.051, year: 2015

Assessment of possible diel and sex-related differences in round goby (Neogobius melanostomus) diet

Czech Academy of Sciences Publication Activity Database

Všetičková, Lucie; Janáč, Michal; Roche, Kevin Francis; Jurajda, Pavel

2015-01-01

Roč. 64, č. 2 (2015), s. 104-111 ISSN 0139-7893 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : invasive species * diel feeding * inter-sex differences * nest-guarding * breeding season Subject RIV: EG - Zoology Impact factor: 0.592, year: 2015

The Tsenkher Structure in the Gobi-Altai, Mongolia: Preliminary Results from the 2007 Expedition

Science.gov (United States)

Komatsu, G.; Ormö, J.; Bayaraa, T.; Matsui, T.; Gereltsetseg, L.; Tserendug, S.; Goto, K.; Gomez-Ortiz, D.; Demberel, S.

2008-03-01

The 3.6-3.7 km Tsenkher structure located in Mongolia was proposed to be an impact crater. Volcanic hypotheses are not ruled out, but its uplifted rim, extensive breccia deposit, and rootless structure are consistent with an impact origin.

Cryptic species of Ponto-Caspian bighead goby of the genus Ponticola (Gobiidae)

DEFF Research Database (Denmark)

Vasil'eva, E. D.; Schwarzhans, Werner; Medvedev, D. A.

2016-01-01

. gorlap which inhabits the northern, western, and southern Caspian Sea. These three allopatric species have ctenoid scales to varying degrees on the crown and nape (100% presence in P. kessleri and complete absence in P. iljini), and there are small differences in the shape of the head, the thickness...... of the beginning of divergence of the considered three cryptic species, as well as isolating barriers that led to allopatric speciation, are discussed....

Strain gage based determination of mixed mode SIFs

Science.gov (United States)

Murthy, K. S. R. K.; Sarangi, H.; Chakraborty, D.

2018-05-01

Accurate determination of mixed mode stress intensity factors (SIFs) is essential in understanding and analysis of mixed mode fracture of engineering components. Only a few strain gage determination of mixed mode SIFs are reported in literatures and those also do not provide any prescription for radial locations of strain gages to ensure accuracy of measurement. The present investigation experimentally demonstrates the efficacy of a proposed methodology for the accurate determination of mixed mode I/II SIFs using strain gages. The proposed approach is based on the modified Dally and Berger's mixed mode technique. Using the proposed methodology appropriate gage locations (optimal locations) for a given configuration have also been suggested ensuring accurate determination of mixed mode SIFs. Experiments have been conducted by locating the gages at optimal and non-optimal locations to study the efficacy of the proposed approach. The experimental results from the present investigation show that highly accurate SIFs (0.064%) can be determined using the proposed approach if the gages are located at the suggested optimal locations. On the other hand, results also show the very high errors (212.22%) in measured SIFs possible if the gages are located at non-optimal locations. The present work thus clearly substantiates the importance of knowing the optimal locations of the strain gages apriori in accurate determination of SIFs.

Columbus State University Global Observation and Outreach for the 2012 Transit of Venus

Science.gov (United States)

Perry, Matthew; McCarty, C.; Bartow, M.; Hood, J. C.; Lodder, K.; Johnson, M.; Cruzen, S. T.; Williams, R. N.

2013-01-01

Faculty, staff and students from Columbus State University’s (CSU’s) Coca-Cola Space Science Center presented a webcast of the 2012 Transit of Venus from three continents to a global audience of 1.4 million unique viewers. Team members imaged the transit with telescopes using white-light, hydrogen-alpha, and calcium filters, from Alice Springs, Australia; the Gobi Desert, Mongolia; Bryce Canyon, UT; and Columbus, GA. Images were webcast live during the transit in partnership with NASA’s Sun-Earth Day program, and Science Center staff members were featured on NASA TV. Local members of the public were brought in for a series of outreach initiatives, in both Georgia and Australia, before and during the transit. The data recorded from the various locations have been archived for use in demonstrating principles such as the historical measurement of the astronomical unit.

Evaluating dispersal potential of an invasive fish by the use of aerobic scope and osmoregulation capacity

DEFF Research Database (Denmark)

Behrens, Jane W.; Deurs, Mikael van; Christensen, Emil Aputsiaq Flindt

2017-01-01

factors such as presence of predators, competitors, and parasites. Early prediction of dispersal potential and future 'area of impact' is challenging, but also a great asset in taking appropriate management actions. Aerobic scope (AS) in fish has been linked to various fitness-related parameters, and may...... waters is unknown to date. We show that AS in round goby is reduced by 30% and blood plasma osmolality increased (indicating reduced capacity for osmoregulation) at salinities approaching oceanic conditions, following slow ramping (5 PSU per week) and subsequent long-term acclimation to salinities...... ranging between 0 and 30 PSU (8 days at final treatment salinities before blood plasma osmolality measurements, 12-20 additional days before respirometry). Survival was also reduced at the highest salinities yet a significant proportion (61%) of the fish survived at 30 PSU. Reduced physiological...

The Hei River Basin in northwestern China - tectonics, sedimentary processes and pathways

Science.gov (United States)

Rudersdorf, Andreas; Nottebaum, Veit; Schimpf, Stefan; Yu, Kaifeng; Hartmann, Kai; Stauch, Georg; Wünnemann, Bernd; Reicherter, Klaus; Diekmann, Bernhard; Lehmkuhl, Frank

2014-05-01

The Hei River Basin (catchment area of c. 130,000 km²) is situated at the transition between the northern margin of the Tibetan Plateau and the southern slopes of Gobi-Tien-Shan. As part of the northwestern Chinese deserts, the Ejina Basin (Gaxun Nur Basin) constitutes the endorheic erosion base of the drainage system. The basin - hosting the second largest continental alluvial fans in the world, is tectonically strongly shaped by the Gobi belt of left-lateral transpression. The tectonic setting in combination with competing climatic driving forces (Westerlies and summer/winter monsoon currents) has supported the formation of a valuable long-time sediment archive comprises at least the last 250,000 yrs. of deposition. It is composed by the interplay of eolian, fluvial and lacustrine sedimentation cycles and today is dominated by widespread (gravel) gobi surfaces, insular dune fields and shallow evaporitic playa areas. Thus, it provides excellent conditions to investigate tectonic evolution and Quaternary environmental changes. Recently, geomorphological, geophysical, neotectonic and mineralogical studies have enhanced the understanding of the environmental history and the modern depositional environment. Moreover, the role of the Hei River Basin as an important source area of silt particles which were later deposited on the Chinese Loess Plateau is evaluated. Therefore, a 230 m long drill core, sediment sections and ca. 700 surface samples throughout the whole catchment and basin were analyzed. Instrumental and historical seismicity are very low, but the proximity to active fault zones and dating irregularities in earlier publications indicate evidence for deformation in the study area. Despite flat topography, indications of active tectonics such as fault-related large-scale lineations can be observed. Seismically deformed unconsolidated lacustrine deposits (seismites), presumably of Holocene age, are evident and must be related to the nearby faults. The upper

Invasive Ponto-Caspian gobies in the diet of piscivorous fish in a European lowland river

Czech Academy of Sciences Publication Activity Database

Mikl, Libor; Adámek, Zdeněk; Roche, Kevin Francis; Všetičková, Lucie; Šlapanský, Luděk; Jurajda, Pavel

2017-01-01

Roč. 190, č. 2 (2017), s. 157-171 ISSN 1863-9135 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : invasive gobiids * fish prey * predatory fish diet * food web structure * invasive species impacts Subject RIV: EG - Zoology OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 1.170, year: 2016

Globalising Assessment: An Ethnography of Literacy Assessment, Camels and Fast Food in the Mongolian Gobi

Science.gov (United States)

Maddox, Bryan

2014-01-01

What happens when standardised literacy assessments travel globally? The paper presents an ethnographic account of adult literacy assessment events in rural Mongolia. It examines the dynamics of literacy assessment in terms of the movement and re-contextualisation of test items as they travel globally and are received locally by Mongolian…

The diet of reservoir perch before, during and after establishment of non-native tubenose goby

Czech Academy of Sciences Publication Activity Database

Všetičková, Lucie; Mikl, Libor; Adámek, Zdeněk; Prášek, Václav; Roche, Kevin Francis; Jurajda, Pavel

2018-01-01

Roč. 419, č. 419 (2018), č. článku 4. ISSN 1961-9502 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : dietary shift * food preference * Gobiidae * invasive species * Perca fluviatilis * piscivore diet Subject RIV: EG - Zoology Impact factor: 1.217, year: 2016

Preliminary Result of Geophysical Some Studieson the Nariinsukhait Coal Deposit

Science.gov (United States)

Norov, B.; Purevjav, N.; Roy, D. K., Sr.

2017-12-01

Nariinsukhait coal deposit has a strategic importance on Mongolian national economic development. The deposit is located in Gurvan-tes of the Umnu-gobi province, as 849 km south-west away from Ulaanbaatar. The deposit in geographically, belongs to Gobi Altai region region of the Altai mountain region. The area contains Permian, Cretaceous, Jurassic, Triassic age of sediments. Sediments are red or sedimentary cover on some part of area (Minjin. Ch., Batnyam. D., Rentsendorj. S (Baatarkhuyag. A., Altantsetseg. D., 2015). The coal deposit is located in the center portion of the Nariinsukhait basin. The age of coal hosted sedimentary rock is Jurassic estimated by Paleo-botanic methodology, using examination of a total 59 kind of plants, 288 pollen grains (Baatarkhuyag. A., Altantsetseg. D., 2015). The thickness of coal hosted sedimentary sequence is approximately 1105.5m and named as Orgilohbulag formation. In case of geophysical exploration, preliminary interpretation of the coal basin has been done by 3 geophysical methodologies which commonly applying during exploration stage of coal. The interpretations are given below. Natural Gamma Sonde /NGRS 4140/: use to determine natural gamma activation on rock by radionuclides content (238U; 235U; 232Th; 40K). During measurements well contrasted coal bedding and, value indicate between 0-15cps. And depending on the rock type it has been changed, in case of siltstone, argillite, conglomerate value fluctuated between 15-40cps. However, those rocks natural gamma values are difference little, therefore not showing much contrast between rock types. Formation Density Sonde Version B /FDSB 4036/: The Nariinsukhait coal deposit Open holes and protective pipes of density is 0.5-1.5 g/cm3, 1.2-2.3 g/cm3 respectively. Not well contrasted during measurement due to some of sedimentary rock density range is so low as such sandstone, siltstone, and conglomerate. Therefore, applied resistivity methodology and done interpretation. DLL3

Morphological selection in an extreme flow environment: body shape and waterfall-climbing success in the Hawaiian stream fish Sicyopterus stimpsoni.

Science.gov (United States)

Blob, Richard W; Bridges, William C; Ptacek, Margaret B; Maie, Takashi; Cediel, Roberto A; Bertolas, Morgan M; Julius, Matthew L; Schoenfuss, Heiko L

2008-12-01

Flow characteristics are a prominent factor determining body shapes in aquatic organisms, and correlations between body shape and ambient flow regimes have been established for many fish species. In this study, we investigated the potential for a brief period of extreme flow to exert selection on the body shape of juvenile climbing Hawaiian gobiid fishes. Because of an amphidromous life history, juvenile gobies that complete an oceanic larval phase return to freshwater habitats, where they become adults. Returning juveniles often must scale waterfalls (typically with the use of a ventral sucker) in order to reach the habitats they will use as adults, thereby exposing these animals to brief periods of extreme velocities of flow. Hydrodynamic theory predicts that bodies with larger suckers and with lower heights that reduce drag would have improved climbing success and, thus, be well suited to meet the demands of the flows in waterfalls. To test the potential for the flow environment of waterfalls to impose selection that could contribute to differences in body shape between islands, we subjected juvenile Sicyopterus stimpsoni to climbing trials up artificial waterfalls (∼100 body lengths) and measured differences in body shape between successful and unsuccessful climbers. Waterfalls appear to represent a significant selective barrier to these fishes, as nearly 30% failed our climbing test. However, the effects of selection on morphology were not straightforward, as significant differences in shape between successful and unsuccessful climbers did not always match hydrodynamic predictions. In both selection experiments and in adult fish collected from habitats with different prevailing conditions of flow (the islands of Hawai'i versus Kaua'i), lower head heights were associated with exposure to high-flow regimes, as predicted by hydrodynamic theory. Thus, a premium appears to be placed on the reduction of drag via head morphology throughout the ontogeny of this

Intraabdominal pressure in women during CrossFit exercises and the effect of age and parity.

Science.gov (United States)

Gephart, Laura Faye; Doersch, Karen M; Reyes, Michelle; Kuehl, Thomas J; Danford, Jill M

2018-07-01

To determine intraabdominal pressure (IAP) in women during CrossFit and to determine whether parity, age, or CrossFit experience affects IAP during CrossFit exercises, we evaluated 10 women: 5 experienced and active CrossFitters and 5 who were not regularly engaged in CrossFit. A Laborie urodynamics abdominal pressure probe with the Goby wireless system measured IAP during 10 repetitions of 13 different CrossFit exercises. Women had a mean age of 36 years. A significant difference was found between mean peak IAP of the 5 parous vs the 5 nulliparous women ( P = 0.009). Experience with CrossFit did not affect mean peak IAP achieved with exercise. In some exercises, there was a significant change in IAP as participants progressed through repetitions ( P = 0.003 for back squats and 0.04 for sit-ups). Participants achieved IAP values that were markedly higher than those previously published.

Body size mediates social and environmental effects on nest building behaviour in a fish with paternal care.

Science.gov (United States)

Lehtonen, Topi K; Lindström, Kai; Wong, Bob B M

2015-07-01

Body size, social setting, and the physical environment can all influence reproductive behaviours, but their interactions are not well understood. Here, we investigated how male body size, male-male competition, and water turbidity influence nest-building behaviour in the sand goby (Pomatoschistus minutus), a marine fish with exclusive paternal care. We found that environmental and social factors affected the nest characteristics of small and large males differently. In particular, association between male size and the level of nest elaboration (i.e. the amount of sand piled on top of the nest) was positive only under clear water conditions. Similarly, male size and nest entrance size were positively associated only in the absence of competition. Such interactions may, in turn, help to explain the persistence of variation in reproductive behaviours, which-due to their importance in offspring survival-are otherwise expected to be under strong balancing selection.

A targeted glycan-related gene screen reveals heparan sulfate proteoglycan sulfation regulates WNT and BMP trans-synaptic signaling.

Directory of Open Access Journals (Sweden)

Neil Dani

Full Text Available A Drosophila transgenic RNAi screen targeting the glycan genome, including all N/O/GAG-glycan biosynthesis/modification enzymes and glycan-binding lectins, was conducted to discover novel glycan functions in synaptogenesis. As proof-of-product, we characterized functionally paired heparan sulfate (HS 6-O-sulfotransferase (hs6st and sulfatase (sulf1, which bidirectionally control HS proteoglycan (HSPG sulfation. RNAi knockdown of hs6st and sulf1 causes opposite effects on functional synapse development, with decreased (hs6st and increased (sulf1 neurotransmission strength confirmed in null mutants. HSPG co-receptors for WNT and BMP intercellular signaling, Dally-like Protein and Syndecan, are differentially misregulated in the synaptomatrix of these mutants. Consistently, hs6st and sulf1 nulls differentially elevate both WNT (Wingless; Wg and BMP (Glass Bottom Boat; Gbb ligand abundance in the synaptomatrix. Anterograde Wg signaling via Wg receptor dFrizzled2 C-terminus nuclear import and retrograde Gbb signaling via synaptic MAD phosphorylation and nuclear import are differentially activated in hs6st and sulf1 mutants. Consequently, transcriptional control of presynaptic glutamate release machinery and postsynaptic glutamate receptors is bidirectionally altered in hs6st and sulf1 mutants, explaining the bidirectional change in synaptic functional strength. Genetic correction of the altered WNT/BMP signaling restores normal synaptic development in both mutant conditions, proving that altered trans-synaptic signaling causes functional differentiation defects.

Sexually selected nest-building--Pomatoschistus minutus males build smaller nest-openings in the presence of sneaker males.

Science.gov (United States)

Svensson, O; Kvarnemo, C

2003-09-01

Both natural selection and sexual selection may act on nest-building. We tested experimentally how different regimes of egg-predation and male-male competition influence nest-building before mating, using the marine fish sand goby, Pomatoschistus minutus. Males with sneaker males present built the smallest nest-openings, smaller than males held alone or with Pomatoschistus microps males (which may predate eggs and compete over nest-sites but not compete over fertilizations). Males with visual access to other nest-building males tended also to build smaller openings than males held alone or with P. microps. Males with egg-predators present built nests with openings not differing significantly from any other treatment. Our results indicate that the small nest-openings found in the sneaker male treatment are sexually selected through protection against sneaking or by female choice. Across treatments, time span before a male started to build his nest also explained variation in nest-opening width; males starting late built larger nest-openings.

The offshore benthic fish community

Science.gov (United States)

Lantry, Brian F.; Lantry, Jana R.; Weidel, Brian C.; Walsh, Maureen; Hoyle, James A.; Schaner, Teodore; Neave, Fraser B.; Keir, Michael

2014-01-01

Lake Ontario’s offshore benthic fish community includes primarily slimy sculpin, lake whitefish, rainbow smelt, lake trout, burbot, and sea lamprey. Of these, lake trout have been the focus of an international restoration effort for more than three decades (Elrod et al. 1995; Lantry and Lantry 2008). The deepwater sculpin and three species of deepwater ciscoes (Coregonus spp.) that were historically important in the offshore benthic zone became rare or were extirpated by the 1960s (Christie 1973; Owens et al. 2003; Lantry et al. 2007b; Roth et al. 2013). Ecosystem changes continue to influence the offshore benthic fish community, including the effects of dreissenid mussels, the near disappearance of burrowing amphipods (Diporeia spp.) (Dermott et al. 2005; Watkins et al. 2007), and the increased abundance and expanded geographic distribution of round goby (see Nearshore Fish Community chapter) (Lantry et al. 2007b). The fish-community objectives for the offshore benthic fish community, as described by Stewart et al. (1999), are:

Feeding ecology and trophic relationships of fish species in the lower Guadiana River Estuary and Castro Marim e Vila Real de Santo António Salt Marsh

Science.gov (United States)

Sá, Rita; Bexiga, Constança; Veiga, Pedro; Vieira, Lina; Erzini, Karim

2006-10-01

In this study we analyze the feeding ecology and trophic relationships of some of the main fish species (Soleidae, Moronidae, Mullidae, Sparidae, Mugilidae, and Batrachoididae) of the lower Estuary of the Guadiana River and the Castro Marim e Vila Real de Santo António Salt Marsh. We examined the stomachs of 1415 fish caught monthly between September 2000 and August 2001. Feeding indices and coefficients were determined and used along with the results of multivariate analysis to develop diagrams of trophic interactions (food webs). Results show that these species are largely opportunistic predators. The most important prey items are amphipods, gobies (Gobiidae), shrimps ( Palaemon serratus and Crangon crangon), and polychaete worms. The lower Estuary and associated salt marshes are important nurseries and feeding grounds for the species studied. In this area, it is therefore important to monitor the effects of changes in river runoff, nutrient input, and temperature that result from construction of the Alqueva Dam upstream.

Spatial extent and dynamics of dam impacts on tropical island freshwater fish assemblages

Science.gov (United States)

Cooney, Patrick B.; Kwak, Thomas J.

2013-01-01

Habitat connectivity is vital to the persistence of migratory fishes. Native tropical island stream fish assemblages composed of diadromous species require intact corridors between ocean and riverine habitats. High dams block fish migration, but low-head artificial barriers are more widespread and are rarely assessed for impacts. Among all 46 drainages in Puerto Rico, we identified and surveyed 335 artificial barriers that hinder fish migration to 74.5% of the upstream habitat. We also surveyed occupancy of native diadromous fishes (Anguillidae, Eleotridae, Gobiidae, and Mugilidae) in 118 river reaches. Occupancy models demonstrated that barriers 2 meters (m) high restricted nongoby fish migration and extirpated those fish upstream of 4-m barriers. Gobies are adapted to climbing and are restricted by 12-m barriers and extirpated upstream of 32-m barriers. Our findings quantitatively illustrate the extensive impact of low-head structures on island stream fauna and provide guidance for natural resource management, habitat restoration, and water development strategies.

Aquatic Nuisance Species Locator

Science.gov (United States)

Data in this map has been collected by the United States Geological Survey's Nonindigenous Aquatic Species program located in Gainesville, Florida (http://nas.er.usgs.gov/default.aspx). This dataset may have some inaccuracies and is only current to June 15, 2012. The species identified in this dataset are not inclusive of all aquatic nuisance species, but rather a subset identified to be at risk for transport by recreational activities such as boating and angling. Additionally, the locations where organisims have been identified are also not inclusive and should be treated as a guide. Organisms are limited to the following: American bullfrog, Asian clam, Asian shore crab, Asian tunicate, Australian spotted jellyfish, Chinese mitten crab, New Zealand mudsnail, Colonial sea squirt, Alewife, Bighead carp, Black carp, Flathead catfish, Grass carp, Green crab, Lionfish, Northern snakehead, Quagga mussel, Round Goby, Ruffe, Rusty crayfish, Sea lamprey, Silver carp, Spiny water flea, Veined rapa whelk, Zebra mussel

The right place for the right job in the photovoltaic life cycle.

Science.gov (United States)

Kawajiri, Kotaro; Genchi, Yutaka

2012-07-03

The potential for photovoltaic power generation (PV) to reduce primary energy consumption (PEC) and CO(2) emissions depends on the physical locations of each stage of its life cycle. When stages are optimally located, CO(2) emissions are reduced nearly ten times as much as when each stage is located in the country having the largest current market share. The usage stage contributes the most to reducing CO(2) emissions and PEC, and total CO(2) emissions actually increase when PV is installed in countries having small CO(2) emissions from electricity generation. Global maps of CO(2) reduction potential indicate that Botswana and Gobi in Mongolia are the optimal locations to install PV due to favorable conditions for PV power generation and high CO(2) emissions from current electricity generation. However, the small electricity demand in those countries limits the contribution to global CO(2) reduction. The type of PVs has a small but significant effect on life cycle PEC and CO(2) emissions.

Deinococcus gobiensis cold shock protein improves salt stress tolerance of escherichia coli

International Nuclear Information System (INIS)

Jiang Shijie; Wang Jin; Yang Mingkun; Chen Ming; Zhang Wei; Luo Xuegang

2013-01-01

The Deinococcus gobiensis I-0, an extremely radiation-resistant bacterium, isolated from the Gobi, has superior resistance to abiotic stress (e.g radiation, oxidation, dehydration and so on). The two cold-shock proteins encoded by csp1 (Dgo_CA1136) and csp2 (Dgo_PA0041) were identified in the complete genome sequence of D. gobiensis. In this study, we showed that D. gobiensis Csp1 protected Escherichia coli cells against cold shock and other abiotic stresses such as salt and osmotic shocks. The quantitative real-time PCR assay shows that the expression of trehalose synthase (otsA, otsB) was up-regulated remarkably under salt stress in the csp1-expressing strain, while no difference in the expression of the genes involved in trehalose degradation (treB and treC). The results suggested that Csp1 caused the accumulation of the trehalose was a major feature for improving tolerance to salt stress in E. coli. (authors)

North-East Asian Super Grid: Renewable energy mix and economics

Science.gov (United States)

Breyer, Christian; Bogdanov, Dmitrii; Komoto, Keiichi; Ehara, Tomoki; Song, Jinsoo; Enebish, Namjil

2015-08-01

Further development of the North-East Asian energy system is at a crossroads due to severe limitations of the current conventional energy based system. For North-East Asia it is proposed that the excellent solar and wind resources of the Gobi desert could enable the transformation towards a 100% renewable energy system. An hourly resolved model describes an energy system for North-East Asia, subdivided into 14 regions interconnected by high voltage direct current (HVDC) transmission grids. Simulations are made for highly centralized, decentralized and country-wide grids scenarios. The results for total system levelized cost of electricity (LCOE) are 0.065 and 0.081 €/(kW·h) for the centralized and decentralized approaches for 2030 assumptions. The presented results for 100% renewable resources-based energy systems are lower in LCOE by about 30-40% than recent findings in Europe for conventional alternatives. This research clearly indicates that a 100% renewable resources-based energy system is THE real policy option.

Evidence for ontogenetically and morphologically distinct alternative reproductive tactics in the invasive round Goby Neogobius melanostomus

NARCIS (Netherlands)

Bleeker, Katinka; Jong, De Karen; Kessel, Van Nils; Hinde, Camilla A.; Nagelkerke, Leopold A.J.

2017-01-01

Alternative reproductive tactics are characterized by the occurrence of discrete alternative morphs that differ in behavioural, morphological and physiological traits within the same sex. Although much effort has been made to describe the behaviour, morphology and physiology of such alternative

A newly established round goby (Neogobius melanostomus) population in the upper stretch of the river Elbe

Czech Academy of Sciences Publication Activity Database

Roche, Kevin Francis; Janáč, Michal; Šlapanský, Luděk; Mikl, Libor; Kopeček, Lukáš; Jurajda, Pavel

2015-01-01

Roč. 416, č. 33 (2015), s. 33 ISSN 1961-9502 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Gobiidae * species introduction * non-native species * population expansion * ship-mediated transport Subject RIV: EH - Ecology, Behaviour Impact factor: 0.978, year: 2015

An Anthropologist among the Psychometricians: Assessment Events, Ethnography, and Differential Item Functioning in the Mongolian Gobi

Science.gov (United States)

Maddox, Bryan; Zumbo, Bruno D.; Tay-Lim, Brenda; Qu, Demin

2015-01-01

This article explores the potential for ethnographic observations to inform the analysis of test item performance. In 2010, a standardized, large-scale adult literacy assessment took place in Mongolia as part of the United Nations Educational, Scientific and Cultural Organization Literacy Assessment and Monitoring Programme (LAMP). In a novel form…

Variabilité selon le captureur de l'efficacité de répulsifs à base d'huiles végétales dans la protection individuelle contre les piqûres de Simulium damnosum s. l.

Directory of Open Access Journals (Sweden)

Sylla M.

2002-12-01

Full Text Available Dans le présent article, nous faisons état de la variabilité selon le captureur de l'efficacité de répulsifs à base d'huiles végétales appliquées sur la peau contre les piqûres de Simulium damnosum s. l. Les expérimentations ont été effectuées en zones de savane (Chaussée-Niaka et de forêt (Soubré de Côte d'Ivoire. Les formulations (lotions, crèmes] testées lors de ces travaux ont été obtenues à partir d'huiles d'amande de palme (Elaeis guineensis, de coco (Cocos nucifera et de gobi (Carapa procera. La technique classique de capture sur homme à l'aide de tubes à hémolyse en matière plastique a été utilisée. Pour chaque journée d'expérimentation, un captureur non traité (jambes non enduites de répulsif servait de témoin. Les résultats indiquent qu'en savane, quels que soient le répulsif et le captureur, la densité simulidienne se situait de 1 à 4, 1 à 6 et de 2 à 10 simulies par homme et par jour lorsque le captureur était respectivement protégé avec le coco, le palmiste et le gobi. Avec les mêmes répulsifs, en zone de forêt, l'agressivité simulidienne variait de 9 à 16, de 2 à 30 et de 8 à 49 piqûres par jour. En comparaison, le témoin recevait de 67 à 90 et de 310 à 533 piqûres par jour, respectivement en zones de savane et de forêt. Malgré les variations importantes dans le nombre de simulies capturées en fonction du captureur choisi, nos résultats montrent que quels que soient le répulsif et l'espèce simulidienne, une protection similaire est conférée à tous les captureurs. Ils indiquent également que le recours à des substances naturelles locales, utilisées comme répulsifs en application dermique, est l'une des meilleures méthodes de protection personnelle contre les simulies.

Non-native western tubenose gobies Proterorhinus semilunaris show distinct site, sex and age-related differences in diet

Czech Academy of Sciences Publication Activity Database

Všetičková, Lucie; Janáč, Michal; Vašek, Mojmír; Roche, Kevin Francis; Jurajda, Pavel

2014-01-01

Roč. 414, č. 10 (2014), s. 1-19 ISSN 1961-9502 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : invasive species * Gobiidae * Proterorhinus semilunaris * diet * site-effect * sex-differences Subject RIV: EG - Zoology Impact factor: 0.928, year: 2014

Individual adjustment of sperm expenditure accords with sperm competition theory.

Science.gov (United States)

Pilastro, Andrea; Scaggiante, Marta; Rasotto, Maria B

2002-07-23

Sperm competition theory predicts that males should strategically allocate their sperm reserves according to the level of sperm competition, defined as the probability that the sperm of two males compete for fertilizing a given set of ova. Substantial evidence from numerous animal taxa suggests that, at the individual level, sperm expenditure increases when the risk of sperm competition is greater. In contrast, according to the "intensity model" of sperm competition [Parker, G. A., Ball, M. A., Stockley, P. & Gage, M. J. G. (1996) Proc. R. Soc. London Ser. B 263, 1291-1297], when more than two ejaculates compete during a given mating event, sperm expenditure should decrease as the number of competing males increases. Empirical evidence supporting this prediction, however, is still lacking. Here we measured sperm expenditure in two gobiid fishes, the grass (Zosterisessor ophiocephalus) and black goby (Gobius niger), in which up to six sneakers can congregate around the nest of territorial males and release their sperm when females spawn. We show that, in accordance with theory, sneaker males of both species release fewer sperm as the number of competitors increases.

Lake Michigan offshore ecosystem structure and food web changes from 1987 to 2008

Science.gov (United States)

Rogers, Mark W.; Bunnell, David B.; Madenjian, Charles P.; Warner, David M.

2014-01-01

Ecosystems undergo dynamic changes owing to species invasions, fisheries management decisions, landscape modifications, and nutrient inputs. At Lake Michigan, new invaders (e.g., dreissenid mussels (Dreissena spp.), spiny water flea (Bythotrephes longimanus), round goby (Neogobius melanostomus)) have proliferated and altered energy transfer pathways, while nutrient concentrations and stocking rates to support fisheries have changed. We developed an ecosystem model to describe food web structure in 1987 and ran simulations through 2008 to evaluate changes in biomass of functional groups, predator consumption, and effects of recently invading species. Keystone functional groups from 1987 were identified as Mysis, burbot (Lota lota), phytoplankton, alewife (Alosa pseudoharengus), nonpredatory cladocerans, and Chinook salmon (Oncorhynchus tshawytscha). Simulations predicted biomass reductions across all trophic levels and predicted biomasses fit observed trends for most functional groups. The effects of invasive species (e.g., dreissenid grazing) increased across simulation years, but were difficult to disentangle from other changes (e.g., declining offshore nutrient concentrations). In total, our model effectively represented recent changes to the Lake Michigan ecosystem and provides an ecosystem-based tool for exploring future resource management scenarios.

Long-term changes of fisheries landings in enclosed gulf lagoons (Amvrakikos gulf, W Greece): Influences of fishing and other human impacts

Science.gov (United States)

Katselis, George N.; Moutopoulos, Dimitrios K.; Dimitriou, Evagelos N.; Koutsikopoulos, Constantin

2013-10-01

The present study analyses long-term annual fishery landings time series (1980-2007) for species derived from six lagoons (covering about 70 km2) around an important European wetland, the fjord-like Amvrakikos gulf. Landing trends for most abundant species revealed that typical lagoon fish species-groups, such as Mugilidae (Mugil cephalus, Chelon labrosus, Liza saliens, Liza aurata and Liza ramada), eels (Anguilla anguilla) and Gobies (mainly Zosteriosessor ophiocephalus) had largely decreased, while the landings of Sparus aurata increased during the entire study period. These trends led to a significant change in species composition during recent years that might be attributed to large-scale climatic changes as well as serious anthropogenic impacts that degraded the water quality and altered the hydrology within the gulf and lagoons, the increase of fishing exploitation in Amvrakikos gulf, the expansion of aquaculture activities within the gulf, the application of new fishing management practices in lagoons, and the increase of fish-eating sea-bird populations. The findings are needed for the implementation of an efficient and integrated management tool for the study of coastal systems.

Establishment of a cell line from kidney of seabass, Lates calcarifer (Bloch

Directory of Open Access Journals (Sweden)

Phromkunthong, W.

2003-01-01

Full Text Available Primary cell culture from caudal fin and kidney of seabass (Lates calcarifer Bloch using tissue explant method were cultured in three different medias with various salt concentrations. Only seabass kidney (SK cells grew well in Leibovitze's-15 medium containing 8 g/l of NaCl supplemented with 10 % fetal bovine serum at an optimum temperature of 25 oC. Over a period of 24 months, SK cells were subcultured over than 75 passages and exhibited epithelial-like cells. The chromosome number of SK cells was 42. The cells were found to be free from bacterial, fungal and mycoplasma contamination. Seabass cells can be kept at -80 oC and/or in liquid nitrogen (-196 oC for at least 24 months with a survival rate of 83.20 and 74.50 %, respectively. Nine fish viruses were tested for their infectivity and this SK cells were susceptible to sand goby virus (SGV, chub reovirus (CRV, snake-head rhabdovirus (SHRV, red seabream iridovirus (RSIV, seabass iridovirus (SIV and grouper iridovirus-2 (GIV-2.

Influence of salinity, competition and food supply on the growth of Gobiosoma robustum and Microgobius gulosus from Florida Bay, U. S. A.

Science.gov (United States)

Schofield, P.J.

2004-01-01

The code Gobiosoma robustum and clown Microgobius gulosus gobies were grown in the laboratory over 27 days at two salinities (5 and 35), two food levels [low (a fixed proportion of initial mass) and high (saturation)] and both with and without the presence of the other species. Both species exhibited greatest growth at the high food level and the low (5) salinity. Neither species was affected by the presence of the other species, and there were no overall differences in growth between the two species. Thus, the observed competitive superiority of G. robustum over M. gulosus does not seem to confer an advantage relative to feeding success. Furthermore, as growth of G. robustum was greater at the lower salinity, it is clear that some factor other than salinity is restricting this species from north-eastern Florida Bay. Additional work on the importance of predation and food resources in various regions of Florida Bay is needed to further evaluate the underlying mechanisms responsible for the bay-wide distribution of these species. ?? 2004 The Fisheries Society of the British Isles.

Digitization of uranium deposit information in basin. A new strategy of ISL sandstone-type uranium deposits exploration

International Nuclear Information System (INIS)

Tan Chenglong

2006-01-01

The discovered ISL sandstone-type uranium deposits in the entire world are mostly blind deposits, many of them occur in bleak desert, gobi desert, and semi-hilly land area. Exploration methods for these deposits mainly depend on great and systematic drilling. There are many large-medium size Meso-Cenozoic sedimentary basins in northern China, and over twenty of them are thick overburden basins which are mostly the virgin land for ISL sandstone-type uranium deposit. Due to the comprehensive national power, geological background, uranium exploration ability, great and systematic drilling is not favorable for prospecting ISL sandstone-type uranium deposit in China. According to the exploration and prospecting experiences for mineral ore bodies at home and abroad, uranium information mapping based on geochemical survey of the basins is a new strategy for ISL sandstone-type uranium deposits. It is an economic, practical, fast and effective method, and has been manifested by the performing information digitization for oil and gas resources, gold mineral resources in China and the mapping of uranium information for whole Europe continent. (authors)

An analysis of the correlation between dust storms in Korea and 137Cs nuclide concentration

International Nuclear Information System (INIS)

Choi, Soo-won; Kim, Jeong-hun; Shin, Sang-hwa; Hwang, Joo-ho

2008-01-01

Dust storms occur in Korea during spring time when fine dust is blown in from the far western regions of western China and Mongolia. A fine powdery dust is blown up into the sky and enters the upper reaches of the atmosphere where it is carried easterly across China then slowly falls to the ground on the Korean peninsula and Japan. The dust originates mostly in the Gobi dessert of China, as well as the yellow earth regions in the middle and upper streams of the Yellow river in China. Previous studies on dust storms have been limited to following or estimating their courses, distribution and frequency, or distribution of the heavy metals they transmit. However, since radionuclides exist in the dust, they must also exist in the dust storms. In this study, we analyzed the correlation of :1 37 Cs nuclide concentration based on a count of annual dust storm occurrence in the city of Suwon, South Korea and assessed seasonal differences of 137 Cs nuclide concentration

The taxonomy of a new parvicursorine alvarezsauroid specimen IVPP V20341 (Dinosauria: Theropoda from the Upper Cretaceous Wulansuhai Formation of Bayan Mandahu, Inner Mongolia, China

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Michael Pittman

2015-06-01

Full Text Available A new parvicursorine alvarezsauroid theropod specimen IVPP V20341 from the Upper Cretaceous Wulansuhai Formation of Bayan Mandahu, Inner Mongolia, China is described. IVPP V20341 appears to be distinguishable amongst alvarezsauroids by possible cervical procoely and relatively larger semi-circular caudal neural canals, but these features are not proposed as autapomorphies because current knowledge of alvarezsauroid necks and tails remains sparse. IVPP V20341 is distinguishable from Linhenykus—the sole parvicursorine at Bayan Mandahu—by the location of the origination points of the anterior caudal transverse processes; in IVPP V20341 this is the anterodorsal corner of the centra, whereas in Linhenykus it is the posterior end of the prezygapophyses. A number of additional tentative differences between IVPP V20341 and Linhenykus are also identified, but cannot be confirmed until further details of anatomical variation along the neck and tail are revealed by future finds. Thus, following the study of IVPP V20341 there are still seven parvicursorine species from the Upper Cretaceous Gobi Basin, but future finds could increase this to eight species.

Mapping Palaeohydrography in Deserts: Contribution from Space-Borne Imaging Radar

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Philippe Paillou

2017-03-01

Full Text Available Space-borne Synthetic Aperture Radar (SAR has the capability to image subsurface features down to several meters in arid regions. A first demonstration of this capability was performed in the Egyptian desert during the early eighties, thanks to the first Shuttle Imaging Radar mission. Global coverage provided by recent SARs, such as the Japanese ALOS/PALSAR sensor, allowed the mapping of vast ancient hydrographic systems in Northern Africa. We present a summary of palaeohydrography results obtained using PALSAR data over large deserts such as the Sahara and the Gobi. An ancient river system was discovered in eastern Lybia, connecting in the past the Kufrah oasis to the Mediterranean Sea, and the terminal part of the Tamanrasett river was mapped in western Mauritania, ending with a large submarine canyon. In southern Mongolia, PALSAR images combined with topography analysis allowed the mapping of the ancient Ulaan Nuur lake. We finally show the potentials of future low frequency SAR sensors by comparing L-band (1.25 GHz and P-band (435 MHz airborne SAR acquisitions over a desert site in southern Tunisia.

Comparison of Damage from Hydrocode Simulations of an Asteroid Airburst or Impact on Land, in Deep, or in Shallow Water

Science.gov (United States)

Robertson, Darrel; Wheeler, Lorien; Mathias, Donovan

2017-01-01

If an asteroid is discovered to be on a collision course with Earth and there is insufficient time for a deflection effort to make it miss Earth completely, should it be redirected to a land or ocean impact? While distance from densely populated areas should obviously be maximized, the differing ability of air blast, seismic waves, and tsunami waves to cause damage at distance does not make the choice between land and ocean impacts an immediately obvious one. More broadly this work is a step towards improving damage models from asteroid impacts. This extended abstract follows the hypothetical scenario of the 2017 IAA Planetary Defense Conference where a 100-250m diameter asteroid is on a potential impact course with Earth. A hydrocode was used to simulate impacts into the most sparsely populated areas along the eastern end of the hypothetical impact corridor- specifically in the Gobi Desert, in the shallow waters of the Sea of Japan, and in the deep waters of the Japan Trench in the Pacific Ocean.

From Desert to Dessert: Why Australian Dust Matters.

Science.gov (United States)

Hunter, K. A.; Mackie, D. S.; Boyd, P. W.; McTainsh, G. H.

2006-12-01

The growth of some types of phytoplankton in several parts of the world ocean, including much of the Southern Ocean, is limited by the supply of iron. Large Australian dust storms uplift, transport and abrade soils, to produce aeolian dust that is a significant source iron to the Southern Ocean. Atmospheric processes that enhance the dissolution of iron from aeolian dusts are of interest and have been studied for material from major dust producing regions like the Sahara, Gobi and Australian deserts; the reported solubility of iron from aeolian dusts ranges from <0.01% to 80%. The characteristic red soils, sands and dusts from Australia are generally believed to consist of quartz grains with a coating of fine grains and crystals of iron oxides, primarily hematite and goethite. The precise mineralogy of soil and dust grain coatings is poorly understood and it also not well known how the coatings are altered during uplift and transport to the ocean. Current models to understand the processes operating during the transport and atmospheric processing of dust include some generalisations and simplifications that are not always warranted and our work has shown the overlooked complexity of the system. Models for aeolian-iron dissolution based on Northern Hemisphere data commonly include the pollutants SOx and NOx. The modern Southern Hemisphere is less polluted and thus resembles past environmental systems. The dissolution of iron from soils of the Saharan, Gobi and Australian deserts in the presence of protons only (i.e. without SOx and NOx) occurs in two phases. The first, faster phase, representing up to 20% of total iron is via a surface-controlled mechanism. The rate determining variable is the exposed surface area of the iron oxides and not the size of the underlying quartz grain. The second, slower, phase of dissolution occurs via the transport-controlled formation of a leached layer. During the simulated aeolian abrasion of Australian soils from dust producing

Effect of hydrogen on hydrogen-methane turbulent non-premixed flame under MILD condition

Energy Technology Data Exchange (ETDEWEB)

Mardani, Amir; Tabejamaat, Sadegh [Department of Aerospace engineering, Amirkabir university of technology (Tehran polytechnic), Hafez Ave., PO. Box: 15875-4413, Tehran (Iran)

2010-10-15

Energy crises and the preservation of the global environment are placed man in a dilemma. To deal with these problems, finding new sources of fuel and developing efficient and environmentally friendly energy utilization technologies are essential. Hydrogen containing fuels and combustion under condition of the moderate or intense low-oxygen dilution (MILD) are good choices to replace the traditional ones. In this numerical study, the turbulent non-premixed CH{sub 4}+H{sub 2} jet flame issuing into a hot and diluted co-flow air is considered to emulate the combustion of hydrogen containing fuels under MILD conditions. This flame is related to the experimental condition of Dally et al. [Proc. Combust. Inst. 29 (2002) 1147-1154]. In general, the modelling is carried out using the EDC model, to describe turbulence-chemistry interaction, and the DRM-22 reduced mechanism and the GRI2.11 full mechanism to represent the chemical reactions of H{sub 2}/methane jet flame. The effect of hydrogen content of fuel on flame structure for two co-flow oxygen levels is studied by considering three fuel mixtures, 5%H{sub 2}+95%CH{sub 4}, 10%H{sub 2}+90%CH{sub 4} and 20% H{sub 2}+80%CH{sub 4}(by mass). In this study, distribution of species concentrations, mixture fraction, strain rate, flame entrainment, turbulent kinetic energy decay and temperature are investigated. Results show that the hydrogen addition to methane leads to improve mixing, increase in turbulent kinetic energy decay along the flame axis, increase in flame entrainment, higher reaction intensities and increase in mixture ignitability and rate of heat release. (author)

The parasite community of round goby Neogobius melanostomus (Pallas, 1814) (Actinopterygii: Gobiidae) newly introduced into the upper Elbe

Czech Academy of Sciences Publication Activity Database

Kvach, Yuriy; Ondračková, Markéta; Janáč, Michal; Jurajda, Pavel

2017-01-01

Roč. 418, April (2017), č. článku 19. ISSN 1961-9502 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : enemy release hypothesis * Neogobius melanostomus * North Sea basin * parasite spillback * Pomphorhynchus tereticollis Subject RIV: EG - Zoology OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 1.217, year: 2016

No effect of round goby Neogobius melanostomus colonisation on young-of-the-year fish density or microhabitat use

Czech Academy of Sciences Publication Activity Database

Janáč, Michal; Valová, Zdenka; Roche, Kevin Francis; Jurajda, Pavel

2016-01-01

Roč. 18, č. 8 (2016), s. 2333-2347 ISSN 1387-3547 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Invasive species * Niche shift * Neogobius melanostomus * Proterorhinus semilunaris * Impact Subject RIV: EH - Ecology, Behaviour Impact factor: 2.473, year: 2016

Mongolian “Neolithic” and Early Bronze Age ground stone tools from the northern edge of the Gobi Desert

Directory of Open Access Journals (Sweden)

Joan S. Schneider

2016-10-01

Full Text Available The transition from the Mongolian Neolithic to the Bronze Age is not well understood. Within Ikh Nart Nature Reserve, over a period of five years, we identified a number of sites with dense surface artefact scatters and features that seem to represent this transition period. Evident in those concentrations are characteristic microblade cores, microblades, “thumbnail" flake scrapers, projectile points, ground stone tools, and stone features of unknown function. Between 2012 and 2014 we collected ground stone artefacts from four sites and sediment samples from three sites. With permission of Mongolian authorities, the artefacts from one site and sediment samples from three sites were sent for botanical analyses to the University of Texas, Austin, Environmental Archaeology Laboratory. Preliminary results indicate that plant remains are present on the ground stone artefacts: dendritic long-cells from a deep pore of one artefact and starch grains from the pores of six of the seven artefacts. These data present the first opportunity to understand what resources “Neolithic” people were processing with ground stone tools in this area and further our opportunity to better understand the little-known “Neolithic”-Early Bronze Age transition period in Central Asia. This paper describes the ground stone artefacts and further explores the results of data retrieved from some of these artefacts.

Invasion rate and population characteristics of the invasive round goby Neogobius melanostomus: effects of density and invasion history

DEFF Research Database (Denmark)

Azour, Farivar; Deurs, Mikael van; Behrens, Jane

2015-01-01

). The established population revealed a broad age distribution and a 1:1 gender ratio, while fish from a recently invaded site were primarily of intermediate ages with a male-biased gender ratio. Otolith analyses suggested that the oldest individuals from the recently invaded area experienced superior growth...

Evolutionary Novelty versus Exaptation: Oral Kinematics in Feeding versus Climbing in the Waterfall-Climbing Hawaiian Goby Sicyopterus stimpsoni

OpenAIRE

Cullen, Joshua A.; Maie, Takashi; Schoenfuss, Heiko L.; Blob, Richard W.

2013-01-01

Species exposed to extreme environments often exhibit distinctive traits that help meet the demands of such habitats. Such traits could evolve independently, but under intense selective pressures of extreme environments some existing structures or behaviors might be coopted to meet specialized demands, evolving via the process of exaptation. We evaluated the potential for exaptation to have operated in the evolution of novel behaviors of the waterfall-climbing gobiid fish genus Sicyopterus. T...

Evolutionary novelty versus exaptation: oral kinematics in feeding versus climbing in the waterfall-climbing Hawaiian Goby Sicyopterus stimpsoni.

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Joshua A Cullen

Full Text Available Species exposed to extreme environments often exhibit distinctive traits that help meet the demands of such habitats. Such traits could evolve independently, but under intense selective pressures of extreme environments some existing structures or behaviors might be coopted to meet specialized demands, evolving via the process of exaptation. We evaluated the potential for exaptation to have operated in the evolution of novel behaviors of the waterfall-climbing gobiid fish genus Sicyopterus. These fish use an "inching" behavior to climb waterfalls, in which an oral sucker is cyclically protruded and attached to the climbing surface. They also exhibit a distinctive feeding behavior, in which the premaxilla is cyclically protruded to scrape diatoms from the substrate. Given the similarity of these patterns, we hypothesized that one might have been coopted from the other. To evaluate this, we filmed climbing and feeding in Sicyopterus stimpsoni from Hawai'i, and measured oral kinematics for two comparisons. First, we compared feeding kinematics of S. stimpsoni with those for two suction feeding gobiids (Awaous guamensis and Lentipes concolor, assessing what novel jaw movements were required for algal grazing. Second, we quantified the similarity of oral kinematics between feeding and climbing in S. stimpsoni, evaluating the potential for either to represent an exaptation from the other. Premaxillary movements showed the greatest differences between scraping and suction feeding taxa. Between feeding and climbing, overall profiles of oral kinematics matched closely for most variables in S. stimpsoni, with only a few showing significant differences in maximum values. Although current data cannot resolve whether oral movements for climbing were coopted from feeding, or feeding movements coopted from climbing, similarities between feeding and climbing kinematics in S. stimpsoni are consistent with evidence of exaptation, with modifications, between these behaviors. Such comparisons can provide insight into the evolutionary mechanisms facilitating exploitation of extreme habitats.

Evolutionary novelty versus exaptation: oral kinematics in feeding versus climbing in the waterfall-climbing Hawaiian Goby Sicyopterus stimpsoni.

Science.gov (United States)

Cullen, Joshua A; Maie, Takashi; Schoenfuss, Heiko L; Blob, Richard W

2013-01-01

Species exposed to extreme environments often exhibit distinctive traits that help meet the demands of such habitats. Such traits could evolve independently, but under intense selective pressures of extreme environments some existing structures or behaviors might be coopted to meet specialized demands, evolving via the process of exaptation. We evaluated the potential for exaptation to have operated in the evolution of novel behaviors of the waterfall-climbing gobiid fish genus Sicyopterus. These fish use an "inching" behavior to climb waterfalls, in which an oral sucker is cyclically protruded and attached to the climbing surface. They also exhibit a distinctive feeding behavior, in which the premaxilla is cyclically protruded to scrape diatoms from the substrate. Given the similarity of these patterns, we hypothesized that one might have been coopted from the other. To evaluate this, we filmed climbing and feeding in Sicyopterus stimpsoni from Hawai'i, and measured oral kinematics for two comparisons. First, we compared feeding kinematics of S. stimpsoni with those for two suction feeding gobiids (Awaous guamensis and Lentipes concolor), assessing what novel jaw movements were required for algal grazing. Second, we quantified the similarity of oral kinematics between feeding and climbing in S. stimpsoni, evaluating the potential for either to represent an exaptation from the other. Premaxillary movements showed the greatest differences between scraping and suction feeding taxa. Between feeding and climbing, overall profiles of oral kinematics matched closely for most variables in S. stimpsoni, with only a few showing significant differences in maximum values. Although current data cannot resolve whether oral movements for climbing were coopted from feeding, or feeding movements coopted from climbing, similarities between feeding and climbing kinematics in S. stimpsoni are consistent with evidence of exaptation, with modifications, between these behaviors. Such comparisons can provide insight into the evolutionary mechanisms facilitating exploitation of extreme habitats.

New Mediterranean Marine biodiversity records (June 2013

Directory of Open Access Journals (Sweden)

I. SIOKOU

2013-04-01

Full Text Available This paper concerns records of species that have extended their distribution in the Mediterranean Sea. The finding of the rare brackish angiosperm Althenia filiformis in the island of Cyprus is interesting since its insertion in the Red Data Book of the Flora of Cyprus is suggested. The following species enriched the flora or fauna lists of the relevant countries: the red alga Sebdenia dichotoma (Greece, the hydrachnid mite Pontarachna adriatica (Slovenia, and the thalassinid Gebiacantha talismani (Turkey. Several alien species were recorded in new Mediterranean localities. The record of the burrowing goby Trypauchen vagina in the North Levantine Sea (Turkish coast, suggests the start of spreading of this Lessepsian immigrant in the Mediterranean Sea. The findings of the following species indicate the extension of their occurrence in the Mediterranean Sea: the foraminifer Amphistegina lobifera (island of Zakynthos, Greece, the medusa Cassiopea andromeda (Syria, the copepod Centropages furcatus (Aegean Sea, the decapod shrimp Melicertus hathor (island of Kastellorizo, Greece, the crab Menoethius monoceros (Gulf of Tunis, the barnacles Balanus trigonus, Megabalanus tintinnabulum, Megabalanus coccopoma and the bivalves Chama asperella, Cucurbitula cymbium (Saronikos Gulf, Greece.

Unusually dynamic sex roles in a fish.

Science.gov (United States)

Forsgren, Elisabet; Amundsen, Trond; Borg, Asa A; Bjelvenmark, Jens

2004-06-03

Sex roles are typically thought of as being fixed for a given species. In most animals males compete for females, whereas the females are more reluctant to mate. Therefore sexual selection usually acts most strongly on males. This is explained by males having a higher potential reproductive rate than females, leading to more males being sexually active (a male-biased operational sex ratio). However, what determines sex roles and the strength of sexual selection is a controversial and much debated question. In this large-scale field study, we show a striking temporal plasticity in the mating competition of a fish (two-spotted goby, Gobiusculus flavescens). Over the short breeding season fierce male-male competition and intensive courtship behaviour in males were replaced by female-female competition and actively courting females. Hence, sex role reversal occurred rapidly. This is the first time that a shift in sex roles has been shown in a vertebrate. The shift might be explained by a large decline in male abundance, strongly skewing the sex ratio towards females. Notably, the sex role reversal did not occur at an equal operational sex ratio, contrary to established sex role theory.

Desert Dust and Health: A Central Asian Review and Steppe Case Study

Directory of Open Access Journals (Sweden)

Troy Sternberg

2017-11-01

Full Text Available In Asian deserts environmental and anthropomorphic dust is a significant health risk to rural populations. Natural sources in dry landscapes are exacerbated by human activities that increase the vulnerability to dust and dust-borne disease vectors. Today in Central and Inner Asian drylands, agriculture, mining, and rapid development contribute to dust generation and community exposure. Thorough review of limited dust investigation in the region implies but does not quantify health risks. Anthropogenic sources, such as the drying of the Aral Sea, highlight the shifting dust dynamics across the Central EurAsian steppe. In the Gobi Desert, our case study in Khanbogd, Mongolia addressed large-scale mining’s potential dust risk to the health of the local population. Dust traps showed variable exposure to particulates among herder households and town residents; dust density distribution indicated that sources beyond the mine need to be considered when identifying particulate sources. Research suggests that atmospheric dust from multiple causes may enhance human particulate exposure. Greater awareness of dust in greater Central Asia reflects community concern about related health implications. Future human well-being in the region will require more thorough information on dust emissions in the changing environment.

Determining the Frequency of Dry Lake Bed Formation in Semi-Arid Mongolia From Satellite Data

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Yuta Demura

2017-12-01

Full Text Available In the Mongolian Plateau, the desert steppe, mountains, and dry lake bed surfaces may affect the process of dust storm emissions. Among these three surface types, dry lake beds are considered to contribute a substantial amount of global dust emissions and to be responsible for “hot spots” of dust outbreaks. The land cover types in the study area were broadly divided into three types, namely desert steppe, mountains, and dry lake beds, by a classification based on Normalized Difference Water Index (NDWI calculated from MODIS Terra satellite images, and Digital Elevation Model (DEM. This dry lake beds extracting method using remote sensing offers a new technique for identifying dust hot spots and potential untapped groundwater in the dry lands of the Gobi region. In the study area, frequencies of dry lake bed formation were calculated during the period of 2001 to 2014. The potential dry lake area corresponded well with the length of the river network based on hydrogeological characterization (R2 = 0.77, p < 0.001. We suggest that the threshold between dry lake bed areas and the formation of ephemeral lakes in semi-arid regions is eight days of total precipitation.

Impacts of aquatic nonindigenous invasive species on the Lake Erie ecosystem

Science.gov (United States)

Austen, Madeline J.W.; Ciborowski, Jan J.H.; Corkum, Lynda D.; Johnson, Tim B.; MacIsaac, Hugh J.; Metcalfe-Smith, Janice L.; Schloesser, Donald W.; George, Sandra E.

2002-01-01

Lake Erie is particularly vulnerable to the introduction and establishment of aquatic nonindigenous invasive species (NIS) populations. A minimum of 144 aquatic NIS have been recorded in the Lake Erie basin including several species [e.g., Eurasian watermilfoil (Myriophyllum spicatum); zebra mussel (Dreissena polymorpha); quagga mussel (Dreissena bugensis); an amphipod (Echinogammarus ischnus); round goby (Neogobius melanostomus); and sea lamprey (Petromyzon marinus)] that have had discernible impacts on the lake's ecology. NIS pose threats to the Lake Erie ecosystem for a variety of reasons including their ability to proliferate quickly, compete with native species, and transfer contaminants (e.g., PCBs) and disease through the food web. Six of the 14 beneficial use impairments listed in Annex 2 of the Great Lakes Water Quality Agreement are impaired in Lake Erie, in part as a result of the introduction of NIS. The Lake Erie Lakewide Management Plan (LaMP) has adopted an ecosystem approach to restore beneficial use impairments in the lake. Furthermore, a research consortium, known as the Lake Erie Millennium Network, is working alongside the LaMP, to address research problems regarding NIS, the loss of habitat, and the role of contaminants in the Lake Erie ecosystem.

The community structure of over-wintering larval and small juvenile fish in a large estuary

Science.gov (United States)

Munk, Peter; Cardinale, Massimiliano; Casini, Michele; Rudolphi, Ann-Christin

2014-02-01

The Skagerrak and Kattegat are estuarine straits of high hydrographical and ecological diversity, situated between the saline waters of the North Sea and the brackish waters of the Baltic Sea. These sustain important nursery grounds of many fish species, of which several overwinter during the larval and early juvenile stages. In order to give more insight into the communities of the overwintering ichthyoplankton in estuarine areas, we examine an annual series of observations from a standard survey carried out 1992-2010. Species differences and annual variability in distributions and abundances are described, and linkages between ichthyoplankton abundances and corresponding hydrographical information are analysed by GAM methods. Communities were dominated by herring, gobies, butterfish, sprat, pipefishes, lemon sole and European eel (i.e. glass eel), and all the sampled species showed large annual fluctuations in abundances. The species showed quite specific patterns of distribution although species assemblages with common distributional characteristics were identified. Within these assemblages, the ichthyoplankton abundances showed linkage to environmental characteristics described by bottom-depth and surface temperature and salinity. Hence the study points to a significant structuring of overwintering ichthyoplankton communities in large estuaries, based on the species habitat choice and its response to physical gradients.

Ecological conversion efficiency and its influencers in twelve species of fish in the Yellow Sea Ecosystem

Science.gov (United States)

Tang, Qisheng; Guo, Xuewu; Sun, Yao; Zhang, Bo

2007-09-01

The ecological conversion efficiencies in twelve species of fish in the Yellow Sea Ecosystem, i.e., anchovy ( Engraulis japonicus), rednose anchovy ( Thrissa kammalensis), chub mackerel ( Scomber japonicus), halfbeak ( Hyporhamphus sajori), gizzard shad ( Konosirus punctatus), sand lance ( Ammodytes personatus), red seabream ( Pagrus major), black porgy ( Acanthopagrus schlegeli), black rockfish ( Sebastes schlegeli), finespot goby ( Chaeturichthys stigmatias), tiger puffer ( Takifugu rubripes), and fat greenling ( Hexagrammos otakii), were estimated through experiments conducted either in situ or in a laboratory. The ecological conversion efficiencies were significantly different among these species. As indicated, the food conversion efficiencies and the energy conversion efficiencies varied from 12.9% to 42.1% and from 12.7% to 43.0%, respectively. Water temperature and ration level are the main factors influencing the ecological conversion efficiencies of marine fish. The higher conversion efficiency of a given species in a natural ecosystem is acquired only under the moderate environment conditions. A negative relationship between ecological conversion efficiency and trophic level among ten species was observed. Such a relationship indicates that the ecological efficiency in the upper trophic levels would increase after fishing down marine food web in the Yellow Sea ecosystem.

Long range transport of fine particle windblown soils and coal fired power station emissions into Hanoi between 2001 to 2008

Energy Technology Data Exchange (ETDEWEB)

Cohen, D.D.; Crawford, J.; Stelcer, E.; Vuong, T.B. [Australian Nuclear Science & Technology Organisation, Kirrawee DC, NSW (Australia)

2010-10-15

Fine particulate matter (PM2.5), source fingerprints and their contributions have been measured and reported previously at Hanoi, Vietnam, from 25 April 2001 to 31 December 2008. In this study back trajectories are used to identify long range transport into Hanoi for two of these sources, namely, windblown dust (Soil) from 12 major deserts in China and emissions from 33 coal fired power plants (Coal) in Vietnam and China. There were 28 days of extreme Soil events with concentrations greater than 6 {mu} g m{sup -3} and 25 days of extreme Coal with concentrations greater than 30 {mu} g m{sup -3} from a total of 748 sampling days during the study period. Through the use of back trajectories it was found that long range transport of soil from the Taklamakan and Gobi desert regions (more than 3000 km to the north west) accounted for 76% of the extreme events for Soil. The three local Vietnamese power stations contributed to 15% of the extreme Coal events, while four Chinese power stations between 300 km and 1700 km to the north-east of Hanoi contributed 50% of the total extreme Coal events measured at the Hanoi sampling site.

Long-term stability of the near-field about high-level radioactive waste repository in thermo-hydro-mechanical coupling action condition

International Nuclear Information System (INIS)

Liu Yuemiao; Wang Ju; Ke Dan; Cai Meifeng

2008-01-01

It is a long-term process for the high-level radioactive waste repository, from opening, construction to end of its service. The long-term stability of the near-field is the key issue for the design of HLW repository because the opening and heat generated from the HLW. Through a nationwide investigation, Beishan area, a Gobi desert in Gansu province, is considered as a suitable candidate and GMZ bentonite deposit which located in Xinghe County, Inner Mongolia has been proposed for the supplier of buffer/backfill material for HLW geological repository in China. According to the R and D guide of high-level radioactive waste disposal in China, the 3D model of HLW repository with high-level radioactive waste, canister and buffer/backfill material is established using FLAC3D. To take into account in situ stress, geothermal gradient, groundwater, thermal relief of HLW and swelling pressure of buffer/backfill material, the evolution of temperature, stress and displacement of HLW repository under thermo-mechanical coupling, hydro-mechanical coupling and thermo-hydro-mechanical coupling conditions was analyzed respectively. The long-term stability of HLW repository in Beishan area was studied. (authors)

Atmospheric environment measurement 3. Environmental pollution monitoring system using PIXE analysis

International Nuclear Information System (INIS)

Ishii, Keizo

2009-01-01

The PIXE(Proton Induced X-ray Emission) method is used in various fields owing to its high sensitivity. This method can be used to analyze multiple elements in a short time and therefore is suitable for the analysis of large quantities of environmental samples. We researched the effect of removing footwear in a room on indoor aerosol pollution. The concentration of aerosol particles in the case that footwear was not removed was 5 times larger than in the case when footwear was removed. We were able to identify a source of air pollution using both the results of PIXE analysis and information on wind direction. We applied PIXE analysis to investigate airborne yellow sand, which originals from the Gobi desert. By analyzing each yellow sand particle, hazardous yellow sand could be detected. We also applied PIXE analysis to river water pollution. River water samples were collected at a number of points along a river. The dilution of metallic elements by the river water was observed. Thus, it was shown that monitoring systems using the PIXE method are very useful for monitoring environmental pollution. (author)

Desert Dust and Health: A Central Asian Review and Steppe Case Study.

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Sternberg, Troy; Edwards, Mona

2017-11-03

In Asian deserts environmental and anthropomorphic dust is a significant health risk to rural populations. Natural sources in dry landscapes are exacerbated by human activities that increase the vulnerability to dust and dust-borne disease vectors. Today in Central and Inner Asian drylands, agriculture, mining, and rapid development contribute to dust generation and community exposure. Thorough review of limited dust investigation in the region implies but does not quantify health risks. Anthropogenic sources, such as the drying of the Aral Sea, highlight the shifting dust dynamics across the Central EurAsian steppe. In the Gobi Desert, our case study in Khanbogd, Mongolia addressed large-scale mining's potential dust risk to the health of the local population. Dust traps showed variable exposure to particulates among herder households and town residents; dust density distribution indicated that sources beyond the mine need to be considered when identifying particulate sources. Research suggests that atmospheric dust from multiple causes may enhance human particulate exposure. Greater awareness of dust in greater Central Asia reflects community concern about related health implications. Future human well-being in the region will require more thorough information on dust emissions in the changing environment.

Seasonal diet pattern of non-native tubenose goby (Proterorhinus semilunaris) in the lowland reservoir (Mušov, Czech Republic)

Czech Academy of Sciences Publication Activity Database

Adámek, Z.; Jurajda, Pavel; Prášek, Václav; Sukop, I.

2010-01-01

Roč. 397, 02 (2010), s. 1-12 ISSN 1961-9502 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60930519 Keywords : Gobiidae * food * lowland reservoir * rip-rap bank * the Dyje River Subject RIV: EG - Zoology Impact factor: 0.304, year: 2010

Pelagic occurrence and diet of invasive round goby Neogobius melanostomus (Actinopterygii, Gobiidae) juveniles in deep well-mixed European reservoirs.

Czech Academy of Sciences Publication Activity Database

Jůza, Tomáš; Zemanová, Jana; Tušer, Michal; Sajdlová, Zuzana; Baran, Roman; Vašek, Mojmír; Ricard, Daniel; Blabolil, Petr; Wagenvoort, A. J.; Ketelaars, H. A. M.; Kubečka, Jan

2016-01-01

Roč. 768, č. 1 (2016), s. 197-209 ISSN 0018-8158 R&D Projects: GA MŠk(CZ) EE2.3.20.0204; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Biesbosch reservoirs * fish community composition changes * invasive species * vertical distribution * length distribution * fry trawling Subject RIV: EH - Ecology, Behaviour Impact factor: 2.056, year: 2016

Feeding kinematics and performance of Hawaiian stream gobies, Awaous guamensis and Lentipes concolor: linkage of functional morphology and ecology.

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Maie, Takashi; Wilson, Megan P; Schoenfuss, Heiko L; Blob, Richard W

2009-03-01

Distributions of Hawaiian stream fishes are typically interrupted by waterfalls that divide streams into multiple segments. Larvae hatch upstream, are flushed into the ocean, and must climb these waterfalls to reach adult habitats when returning back to freshwater as part of an amphidromous life cycle. Stream surveys and studies of climbing performance show that Lentipes concolor Gill can reach fast-flowing upper stream segments but that Awaous guamensis Valenciennes reaches only slower, lower stream segments. Gut content analyses for these two species indicate considerable overlap in diet, suggesting that feeding kinematics and performance of these two species might be comparable. Alternatively, feeding kinematics and performance of these species might be expected to differ in relation to the different flow regimes in their habitat (feeding in faster stream currents for L. concolor versus in slower currents for A. guamensis). To test these alternative hypotheses, we compared food capturing kinematics and performance during suction feeding behaviors of A. guamensis and L. concolor using morphological data and high-speed video. Lentipes concolor showed both a significantly larger gape angle and faster jaw opening than A. guamensis. Geometric models calculated that despite the inverse relationship of gape size and suction pressure generation, the fast jaw motions of L. concolor allow it to achieve higher pressure differentials than A. guamensis. Such elevated suction pressure would enhance the ability of L. concolor to successfully capture food in the fast stream reaches it typically inhabits. Differences in jaw morphology may contribute to these differences in performance, as the lever ratio for jaw opening is about 10% lower in L. concolor compared with A. guamensis, suiting the jaws of L. concolor better for fast opening. Copyright 2008 Wiley-Liss, Inc.

Seasonal distribution of Dall's porpoise in Prince William Sound, Alaska

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Moran, John R.; O'Dell, Matthew B.; Arimitsu, Mayumi L.; Straley, Janice M.; Dickson, Danielle M. S.

2018-01-01

Dall's porpoise, Phocoenoides dalli, are a conspicuous predator in the Prince William Sound ecosystem, yet there has been little effort directed towards monitoring this species since the 1980s, prior to the Exxon Valdez oil spill. We used vessel-based surveys to examine the seasonal distribution of Dall's porpoise in the waters of Prince William Sound during eight years from 2007 to 2015. Over the course of 168 days and 15,653 km of survey effort, 921 Dall's porpoise were encountered in 210 groups. We estimate an encounter rate of 0.061 porpoise/km traveled or 1 porpoise encountered for every 16.5 km traveled. Dall's porpoise were found throughout the year in Prince William Sound, and used a wide range of habitats, including those not considered typical of the species, such as bays, shallow water, and nearshore waters. Dall's porpoise seasonally shifted their center of distribution from the western passages in fall to the bays of the eastern Sound in winter and spring. Dall's porpoises were widely dispersed throughout the Sound in summer. We identified potential Dall's porpoise habitat (depth, slope, and distance from shore) within Prince William Sound using generalized additive models (GAM). Dall's porpoise were found in deeper water during summer and in shallowest water during spring. We propose that their use of novel habitats is a function of reduced predation risk associated with the decline of their main predator, killer whales (Orcinus orca), following the Exxon Valdez oil spill, and the presence of overwintering and spawning Pacific herring (Clupea pallasii). While the size of the Dall's porpoise population within Prince William Sound remains unknown, our encounter rates were lower than those reported in the 1970s. Their high metabolic rate and ubiquitous presence makes them one of the more important, yet understudied, forage fish predators in the region.

Canyon Creek: A late Pleistocene vertebrate locality in interior Alaska

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Weber, Florence R.; Hamilton, Thomas D.; Hopkins, David M.; Repenning, Charles A.; Haas, Herbert

1981-09-01

The Canyon Creek vertebrate-fossil locality is an extensive road cut near Fairbanks that exposes sediments that range in age from early Wisconsin to late Holocene. Tanana River gravel at the base of the section evidently formed during the Delta Glaciation of the north-central Alaska Range. Younger layers and lenses of fluvial sand are interbedded with arkosic gravel from Canyon Creek that contains tephra as well as fossil bones of an interstadial fauna about 40,000 years old. Solifluction deposits containing ventifacts, wedge casts, and rodent burrows formed during a subsequent period of periglacial activity that took place during the maximum phase of Donnelly Glaciation about 25,000-17,000 years ago. Overlying sheets of eolian sand are separated by a 9500-year-old paleosol that may correlate with a phase of early Holocene spruce expansion through central Alaska. The Pleistocene fauna from Canyon Creek consists of rodents (indicated by burrows), Mammuthus primigenius (woolly mammoth), Equus lambei (Yukon wild ass), Camelops hesternus (western camel), Bison sp. cf. B. crassicornis (large-horned bison), Ovis sp. cf. O. dalli (mountain sheep), Canis sp. cf. C. lupus (wolf), Lepus sp. cf. L. othus or L. arcticus (tundra hare), and Rangifer sp. (caribou). This assemblage suggests an open landscape in which trees and tall shrubs were either absent or confined to sheltered and moist sites. Camelops evidently was present in eastern Beringia during the middle Wisconsin interstadial interval but may have disappeared during the following glacial episode. The stratigraphic section at Canyon Creek appears to demonstrate that the Delta Glaciation of the north-central Alaska Range is at least in part of early Wisconsin age and was separated from the succeeding Donnelly Glaciation by an interstadial rather than interglacial episode.

Fragile X mental retardation protein regulates trans-synaptic signaling in Drosophila

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Samuel H. Friedman

2013-11-01

Fragile X syndrome (FXS, the most common inherited determinant of intellectual disability and autism spectrum disorders, is caused by loss of the fragile X mental retardation 1 (FMR1 gene product (FMRP, an mRNA-binding translational repressor. A number of conserved FMRP targets have been identified in the well-characterized Drosophila FXS disease model, but FMRP is highly pleiotropic in function and the full spectrum of FMRP targets has yet to be revealed. In this study, screens for upregulated neural proteins in Drosophila fmr1 (dfmr1 null mutants reveal strong elevation of two synaptic heparan sulfate proteoglycans (HSPGs: GPI-anchored glypican Dally-like protein (Dlp and transmembrane Syndecan (Sdc. Our recent work has shown that Dlp and Sdc act as co-receptors regulating extracellular ligands upstream of intracellular signal transduction in multiple trans-synaptic pathways that drive synaptogenesis. Consistently, dfmr1 null synapses exhibit altered WNT signaling, with changes in both Wingless (Wg ligand abundance and downstream Frizzled-2 (Fz2 receptor C-terminal nuclear import. Similarly, a parallel anterograde signaling ligand, Jelly belly (Jeb, and downstream ERK phosphorylation (dpERK are depressed at dfmr1 null synapses. In contrast, the retrograde BMP ligand Glass bottom boat (Gbb and downstream signaling via phosphorylation of the transcription factor MAD (pMAD seem not to be affected. To determine whether HSPG upregulation is causative for synaptogenic defects, HSPGs were genetically reduced to control levels in the dfmr1 null background. HSPG correction restored both (1 Wg and Jeb trans-synaptic signaling, and (2 synaptic architecture and transmission strength back to wild-type levels. Taken together, these data suggest that FMRP negatively regulates HSPG co-receptors controlling trans-synaptic signaling during synaptogenesis, and that loss of this regulation causes synaptic structure and function defects characterizing the FXS disease state.

Seasonal habitat use and selection by grizzly bears in Northern British Columbia

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Milakovic, B.; Parker, K.L.; Gustine, D.D.; Lay, R.J.; Walker, A.B.D.; Gillingham, M.P.

2012-01-01

We defined patterns of habitat use and selection by female grizzly bears (Ursus arctos) in the Besa-Prophet watershed of northern British Columbia. We fitted 13 adult females with Geographic Positioning System (GPS) radio-collars and monitored them between 2001 and 2004. We examined patterns of habitat selection by grizzly bears relative to topographical attributes and 3 potential surrogates of food availability: land-cover class, vegetation biomass or quality (as measured by the Normalized Difference Vegetation Index), and selection value for prey species themselves (moose [Alces alces], elk [Cervus elaphus], woodland caribou [Rangifer tarandus], Stone's sheep [Ovis dalli stonei]). Although vegetation biomass and quality, and selection values for prey were important in seasonal selection by some individual bears, land-cover class, elevation, aspect, and vegetation diversity most influenced patterns of habitat selection across grizzly bears, which rely on availability of plant foods and encounters with ungulate prey. Grizzly bears as a group avoided conifer stands and areas of low vegetation diversity, and selected for burned land-cover classes and high vegetation diversity across seasons. They also selected mid elevations from what was available within seasonal ranges. Quantifying relative use of different attributes helped place selection patterns within the context of the landscape. Grizzly bears used higher elevations (1,595??31 m SE) in spring and lower elevations (1,436??27 m) in fall; the range of average elevations used among individuals was highest (500 m) during the summer. During all seasons, grizzly bears most frequented aspects with high solar gain. Use was distributed across 10 land-cover classes and depended on season. Management and conservation actions must maintain a diverse habitat matrix distributed across a large elevational gradient to ensure persistence of grizzly bears as levels of human access increase in the northern Rocky Mountains

Strategies in Interventional Radiology: Formation of an Interdisciplinary Center of Vascular Anomalies - Chances and Challenges for Effective and Efficient Patient Management.

Science.gov (United States)

Sadick, Maliha; Dally, Franz Josef; Schönberg, Stefan O; Stroszczynski, Christian; Wohlgemuth, Walter A

2017-10-01

Background  Radiology is an interdisciplinary field dedicated to the diagnosis and treatment of numerous diseases and is involved in the development of multimodal treatment concepts. Method  Interdisciplinary case management, a broad spectrum of diagnostic imaging facilities and dedicated endovascular radiological treatment options are valuable tools that allow radiology to set up an interdisciplinary center for vascular anomalies. Results  Image-based diagnosis combined with endovascular treatment options is an essential tool for the treatment of patients with highly complex vascular diseases. These vascular anomalies can affect numerous parts of the body so that a multidisciplinary treatment approach is required for optimal patient care. Conclusion  This paper discusses the possibilities and challenges regarding effective and efficient patient management in connection with the formation of an interdisciplinary center for vascular anomalies with strengthening of the clinical role of radiologists. Key points   · Vascular anomalies, which include vascular tumors and malformations, are complex to diagnose and treat.. · There are far more patients with vascular anomalies requiring therapy than interdisciplinary centers for vascular anomalies - there is currently a shortage of dedicated interdisciplinary centers for vascular anomalies in Germany that can provide dedicated care for affected patients.. · Radiology includes a broad spectrum of diagnostic and minimally invasive therapeutic tools which allow the formation of an interdisciplinary center for vascular anomalies for effective, efficient and comprehensive patient management.. Citation Format · Sadick M, Dally FJ, Schönberg SO et al. Strategies in Interventional Radiology: Formation of an Interdisciplinary Center of Vascular Anomalies - Chances and Challenges for Effective and Efficient Patient Management. Fortschr Röntgenstr 2017; 189: 957 - 966. © Georg Thieme Verlag KG Stuttgart · New

Brown adipose tissue in cetacean blubber.

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Osamu Hashimoto

Full Text Available Brown adipose tissue (BAT plays an important role in thermoregulation in species living in cold environments, given heat can be generated from its chemical energy reserves. Here we investigate the existence of BAT in blubber in four species of delphinoid cetacean, the Pacific white-sided and bottlenose dolphins, Lagenorhynchus obliquidens and Tursiops truncates, and Dall's and harbour porpoises, Phocoenoides dalli and Phocoena phocoena. Histology revealed adipocytes with small unilocular fat droplets and a large eosinophilic cytoplasm intermingled with connective tissue in the innermost layers of blubber. Chemistry revealed a brown adipocyte-specific mitochondrial protein, uncoupling protein 1 (UCP1, within these same adipocytes, but not those distributed elsewhere throughout the blubber. Western blot analysis of extracts from the inner blubber layer confirmed that the immunohistochemical positive reaction was specific to UCP1 and that this adipose tissue was BAT. To better understand the distribution of BAT throughout the entire cetacean body, cadavers were subjected to computed tomography (CT scanning. Resulting imagery, coupled with histological corroboration of fine tissue structure, revealed adipocytes intermingled with connective tissue in the lowest layer of blubber were distributed within a thin, highly dense layer that extended the length of the body, with the exception of the rostrum, fin and fluke regions. As such, we describe BAT effectively enveloping the cetacean body. Our results suggest that delphinoid blubber could serve a role additional to those frequently attributed to it: simple insulation blanket, energy storage, hydrodynamic streamlining or contributor to positive buoyancy. We believe delphinoid BAT might also function like an electric blanket, enabling animals to frequent waters cooler than blubber as an insulator alone might otherwise allow an animal to withstand, or allow animals to maintain body temperature in cool

Atmosphere aerosol/dust composition over central Asia and western Siberia derived from snow/ice core records and calibrated with NASA remote sensing data

Science.gov (United States)

Aizen, V. B.; Aizen, E. M.; Joswiak, D. R.; Surazakov, A. B.; Takeuchi, N.

2007-12-01

The vast arid and semi-arid regions of central Asia, Mongolia, and Northern China are the world's second largest source of atmospheric mineral dust. In recent years, severe dust storms in Asia have intensified in frequency, duration, and areal coverage. However, limited spatial and temporal extent of aerosol measurements precludes definitive statements to be made regarding relationship between the Asian aerosol generation and climate. It has been well known that glaciers are the natural archives of environmental records related to past climate and aerosol generation. In our research, we utilized central Asian and western Siberia shallow ice-core records recovered from Altai, Tien Shan and Pamir mountain glaciers. Despite the fact that ice-core data may extend climate/aerosol records back in time, their sparse coverage is inadequate to document aerosol spatial distribution. The NASA products from Aura, Terra and Aqua satellite missions address this gap identifying aerosol sources, transport pathways, and area of deposition. The main objective of our research is to evaluate an affect of climate variability on dynamics of Asian aerosol loading to atmosphere and changes in aerosol transport pathways. Dust particle, major and rare earth element analysis from dust aerosols deposited and accumulated in Altai, Tien Shan and Pamir glaciers suggests that loess from Tajikistan, Afghanistan and north-western China are main sources of aerosol loading into the upper troposphere over the central Asia and western Siberia. At the same time, the soluble ionic component of the ice-cores, related to aerosol generated from evaporate deposits, demonstrated both anthropogenic and natural impacts on atmospheric chemistry over these regions. Large perturbations of Ca2+ derived from CaCO3- rich dust transported from Goby Desert to Altai and Tien Shan. Origin and pathway of the ice-core aerosol depositions for the last 10-years were identified through calibrating ice-core records with dust

The Mount Logan (Yukon) Ice Cores: Preliminary Results

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Fisher, D. A.

2004-05-01

Three ice cores were taken at different elevations on or near My Logan in the years 2001 and 2002. The summit core (PRCol) comes from the summit plateau ( 5340 masl, length 187 m to bedrock, mean temperature -29 C ) and was done by the Geological Survey of Canada. The NIPR group cored 210m on the flanks of the mountain at King Col (4200 masl mean temperature -16C) and the UNH group cored 20 km from the mountain at Eclipse "Dome" (3015 masl,length 345 m mean temperature -5C) . The three cores were done cooperatively by GSC, NIPR and UNH and cover nominally 30 ka, 1 ka and 2ka respectively . Located very close to the Gulf of Alaska these core records are thought to reflect the climate history of the Pacific Ocean and having three widely spaced elevations, the sites "see" different distances to different sources. The lowest site (Eclipse) has excellent seasonals but a very muted δ 18O history with no obvious little ice age, whereas the most recent 1ka of the PRCol summit sites contains two very large and sudden δ 18O and d (deuterium excess) shifts at 1850 AD and ~ 800 AD. The δ 18O shifts which happen from one year to the next are about 4 o/oo . The summit site (PRCol) δ 18O response is "backwards", ie the Little Ice Age δ 18O values are 4 o/oo more positive than recent ones. The PRCol δ 18O and d suggest that the source water can either be ëlocalí (Gulf of Alaska) or very distant (tropics) . The Eclipse site seems only to get the local water . A massive dust storm originating in central Asia (Gobi) in April 2001 dumped a visible layer all over the St Elias Mountains and this layer was sampled, to provide a calibration "Asian dust event". The satellite and isotoic signatures both agreed that Gobi was the source. The PRCol record covers the Holocene and well back into the ice age. The transition is defined by a sudden ECM shift on the flanks of a more gradual O18 shift. Acknowledgements. Logan consortium consists of : Geological Survey of Canada : Jocelyne

Retinol, alpha-tocopherol and fatty acid content in Bulgarian black Sea fish species

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Stancheva, M.

2012-06-01

Full Text Available The aim of the present study was to measure and evaluate the total lipids, fatty acid profile, retinol content and alpha-tocopherol content in the edible tissue of four commercially important fish species from the Bulgarian Black sea: Sprat (Sprattus sprattus, Round Goby (Neogobius rattan, Black Sea Horse Mackerel (Trahurus medditeraneus ponticus and Shad (Alosa pontica. Fat soluble vitamins were analyzed simultaneously using an HPLC system. The highest content of retinol was established in the Sprat (142.3 ± 4.4 μg/100g and the highest content of alphatocopherol was found in the Black Sea Horse Mackerel (1112.7 ± 39.2 μg/100g. The fatty acid (FA composition was analyzed by GC/MS. The content of omega 3 (n3 FAs was significantly higher (p , 0.001 than the content of omega 6 (n6 FAs in each of the analyzed fish samples. The n6/n3 FA ratio was within the recommended range (0.20–1.50 for Sprat, Round Goby and Shad. Relatively high levels of retinol and alpha-tocopherol, FA composition, n3/n6 FA and PUFA/SFA ratios indicate that these fish species have good nutritional quality.

El objeto de la investigación presentada es definir y comparar los lípidos totales, el perfil de ácidos grasos y el contenido de retinol y alfa-tocoferol en el tejido comestible de cuatro especies de peces con importancia comercial del Mar Negro búlgaro —espadín (Sprattus Sprattus, gobio de boca negra (Neogobius Melanostomus, chicharro (Trachurus Trachurus y sábalo del Mar Negro (Caspialosa Pontica. Dos vitaminas liposolubles son analizadas simultáneamente mediante cromatografía líquida de alta eficacia (HPLC. El contenido mayor de retinol se encuentra en el espadín (142.3 ± 4.4 μg/100g, y de alfa-tocoferol en el chicharro (1112.7 ± 39.2 μg/100g. El contenido de ácidos grasos ha sido analizado mediante cromatografía gaseosa/espectrometría de masas (GC/MS. El contenido de ácidos grasos (AG