Blood biochemical of nile crocodile ( Crocodylus niloticus ) in Kano ...

African Journals Online (AJOL)

This study investigates serum biochemistry of Nile crocodile from Kano Zoological Garden, Kano, Nigeria. Six (6) adult Nile crocodile (Crocodylus niloticus) were captured from crocodile pond. Blood was collected from post occipital sinus of the physically restrain crocodile and used for serum biochemical parameters.

Alligator Rivers Region

International Nuclear Information System (INIS)

1992-01-01

An introduction to the Alligator Rivers Region is presented. It contains general information regarding the physiography, climate, hydrology and mining of the region. The Alligator Rivers Region is within an ancient basin, the Pine Creek Geosyncline, which has an area of approximately 66000 km 2 . The Geosyncline has a history of mineral exploitation dating back to 1865, during which time 16 metals have been extracted (silver, arsenic, gold, bismuth, cadmium, cobalt, copper, iron, manganese, molybdenum, lead, tin, tantalum, uranium, tungsten, zinc). Uranium exploration in the Pine Creek Geosyncline was stimulated by the discovery in 1949 of secondary uranium mineralisation near Rum June, 70 km south-east of Darwin. This was followed by a decade of intense exploration activity resulting in the discoveries of economic uranium ore bodies at Rum Jungle and in the upper reaches of the South Alligator River Valley. All the known major uranium deposits of the East Alligator River uranium field have been discovered since 1969. The present known resources of the Geosyncline are approximately 360 000 tonnes of contained U 3 O 8 . 2 refs., 2 figs., 1 tab

Levels of mercury in alligators (Alligator mississippiensis) collected along a transect through the Florida Everglades

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Rumbold, D.G.; Fink, L.E.; Laine, K.A.; Niemczyk, S.L.; Chandrasekhar, T.; Wankel, Scott D.; Kendall, C.

2002-01-01

As part of a multi-agency study of alligator health, 28 American alligators (Alligator mississippiensis) were captured along a transect through the Florida Everglades in 1999. Liver and tail muscle tissues were sampled and analyzed on a wet weight basis for total mercury (THg) using cold-vapor atomic absorption spectrophotometry. All tissues had detectable concentrations of THg that ranged from 0.6 to 17 mg/kg in liver and from 0.1 to 1.8 mg/kg in tail muscle. THg was more concentrated in liver tissue than tail muscle, but levels were highly correlated between tissues. THg concentrations in tissue differed significantly among locations, with animals from Everglades National Park (ENP) having mean concentrations of THg in liver (10.4 mg/kg) and tail muscle (1.2 mg/kg) that were two-fold higher than basin-wide averages (4.9 and 0.64 mg/kg, respectively). The reasons for higher contamination of ENP alligators were unclear and could not be explained by differences in sex, length, weight or animal age. While ??15N values were positively correlated with THg concentrations in tail muscle, spatial patterns in isotopic composition did not explain the elevated THg levels in ENP alligators. Therefore, it appears that ENP alligators were more highly exposed to mercury in their environment than individuals in other areas. Comparisons to a previous survey by Yanochko et al. [Arch Environ Contam Toxicol 32 (1997) 323] suggest that mercury levels have declined in some Everglades alligators since 1994. ?? 2002 Elsevier Science B.V. All rights reserved.

Biological activity of alligator, avian, and mammalian insulin in juvenile alligators: plasma glucose and amino acids.

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Lance, V A; Elsey, R M; Coulson, R A

1993-02-01

The biological activity of alligator, turkey, and bovine insulin on plasma glucose and plasma amino acids was tested in fasted juvenile alligators. Preliminary experiments showed that the stress associated with taking the initial blood sample resulted in a hyperglycemic response lasting more than 24 hr. Despite repeated bleedings no additional hyperglycemic events occurred, and blood glucose declined slowly over the next 7 days. Under these conditions the smallest dose of insulin eliciting a hypoglycemic response was 40 micrograms/kg body wt. A dose of 400 micrograms/kg body wt of either alligator or bovine insulin caused a pronounced hypoglycemia by 12 hr postinjection. Maximum decline in plasma glucose occurred at 24 to 36 hr with a slow return to control levels by 120 hr. There were no significant differences in the hypoglycemic responses to any of the three insulins tested. The decline in plasma amino acids was much more rapid than the decline in plasma glucose in response to insulin. Even at the 40 micrograms/kg body wt dose a significant difference from saline-injected control was seen at 2 hr postinjection. Maximum decline in plasma amino acids occurred at 8 to 12 hr with a return to baseline by 36 hr. These results show that the relatively conservative changes in the sequence of alligator insulin (three amino acid substitutions in the B-chain compared with that of chicken) have little effect on biological activity and that alligator insulin receptors do not appear to discriminate among the three insulins.

Oral and cloacal microflora of wild crocodiles Crocodylus acutus and C. moreletii in the Mexican Caribbean.

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Charruau, Pierre; Pérez-Flores, Jonathan; Pérez-Juárez, José G; Cedeño-Vázquez, J Rogelio; Rosas-Carmona, Rebeca

2012-02-17

Bacterial cultures and chemical analyses were performed from cloacal and oral swabs taken from 43 American crocodiles Crocodylus acutus and 28 Morelet's crocodiles C. moreletii captured in Quintana Roo State, Mexico. We recovered 47 bacterial species (28 genera and 14 families) from all samples with 51.1% of these belonging to the family Enterobacteriaceae. Fourteen species (29.8%) were detected in both crocodile species and 18 (38.3%) and 15 (31.9%) species were only detected in American and Morelet's crocodiles, respectively. We recovered 35 bacterial species from all oral samples, of which 9 (25.8%) were detected in both crocodile species. From all cloacal samples, we recovered 21 bacterial species, of which 8 (38.1%) were detected in both crocodile species. The most commonly isolated bacteria in cloacal samples were Aeromonas hydrophila and Escherichia coli, whereas in oral samples the most common bacteria were A. hydrophila and Arcanobacterium pyogenes. The bacteria isolated represent a potential threat to crocodile health during conditions of stress and a threat to human health through crocodile bites, crocodile meat consumption or carrying out activities in crocodile habitat. We especially warn about the presence of Salmonella arizonae and S. typhi, which cause enteritis and septicemia in crocodiles and salmonellosis and typhoid fever in humans. The risk of bacterial contamination from crocodiles to humans could increase in the future because of the accelerated destruction of crocodile habitat, which could lead to an augmentation of human-crocodile interactions. Information on bacterial diversity reported here could help in the choice of antibacterial products in case of infections that are of crocodile origin.

Feeding mechanics in spinosaurid theropods and extant crocodilians.

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Andrew R Cuff

Full Text Available A number of extant and extinct archosaurs evolved an elongate, narrow rostrum. This longirostrine condition has been associated with a diet comprising a higher proportion of fish and smaller prey items compared to taxa with broader, more robust snouts. The evolution of longirostrine morphology and a bulbous anterior rosette of premaxillary teeth also occurs in the spinosaurid theropod dinosaurs, leading to suggestions that at least some members of this clade also had a diet comprising a notable proportion of fish or other small vertebrates. Here we compare the rostral biomechanics of the spinosaurs Baryonyx walkeri and Spinosaurus c.f. S. aegyptiacus to three extant crocodilians: two longistrine taxa, the African slender-snouted crocodile Mecistops cataphractus and the Indian gharial Gavialis gangeticus; and the American alligator Alligator mississippiensis. Using computed tomography (CT data, the second moments of area and moments of inertia at successive transverse slices along the rostrum were calculated for each of the species. Size-independent results tested the biomechanical benefits of material distribution within the rostra. The two spinosaur rostra were both digitally reconstructed from CT data and compared against all three crocodilians. Results show that African slender-snouted crocodile skulls are more resistant to bending than an equivalent sized gharial. The alligator has the highest resistances to bending and torsion of the crocodiles for its size and greater than that of the spinosaurs. The spinosaur rostra possess similar resistance to bending and torsion despite their different morphologies. When size is accounted for, B. walkeri performs mechanically differently from the gharial, contradicting previous studies whereas Spinosaurus does not. Biomechanical data support known feeding ecology for both African slender-snouted crocodile and alligator, and suggest that the spinosaurs were not obligate piscivores with diet being

Molecular and functional characterization of BAFF from the Yangtze alligator (Alligator sinensis, Alligatoridae).

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Zhang, Jia-Xin; Song, Ren; Sang, Ming; Sun, Si-Qing; Ma, Lei; Zhang, Jie; Zhang, Shuang-Quan

2015-10-01

B-cell activating factor (BAFF) from the TNF family is critical for B-cell survival and maturation. In this study, we identified a Yangtze alligator (Alligator sinensis, Alligatoridae) BAFF cDNA, designated as asBAFF, using reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The open reading frame of this cDNA encodes a 287-amino acid protein containing a predicted transmembrane domain and a furin protease cleavage site, similar to mammalian and avian BAFF. The amino acid identity between biologically soluble asBAFF (assBAFF) and csBAFF, hsBAFF, and msBAFF is 94, 76, and 71%, respectively. Real-time quantitative PCR analysis showed that the asBAFF gene is strongly expressed in the spleen. Since BAFF is always expressed as inclusion bodies in bacteria, it is difficult to purify. To enhance the soluble expression of assBAFF in Escherichia coli, we fused the extracellular region of the asBAFF gene to a small ubiquitin-related modifier gene (SUMO). Purified assBAFF was able to promote the survival of splenic lymphocytes and co-stimulate the proliferation of mouse B cells with anti-mouse IgM. These findings suggest that asBAFF plays an important role in the survival and proliferation of Yangtze alligator B cells, and because it is evolutionarily highly conserved, functional cross-reactivity exists between mammalian and Yangtze alligator BAFF. Copyright © 2015 Elsevier GmbH. All rights reserved.

Bioprospecting the American alligator (Alligator mississippiensis host defense peptidome.

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Barney M Bishop

Full Text Available Cationic antimicrobial peptides and their therapeutic potential have garnered growing interest because of the proliferation of bacterial resistance. However, the discovery of new antimicrobial peptides from animals has proven challenging due to the limitations associated with conventional biochemical purification and difficulties in predicting active peptides from genomic sequences, if known. As an example, no antimicrobial peptides have been identified from the American alligator, Alligator mississippiensis, although their serum is antimicrobial. We have developed a novel approach for the discovery of new antimicrobial peptides from these animals, one that capitalizes on their fundamental and conserved physico-chemical properties. This sample-agnostic process employs custom-made functionalized hydrogel microparticles to harvest cationic peptides from biological samples, followed by de novo sequencing of captured peptides, eliminating the need to isolate individual peptides. After evaluation of the peptide sequences using a combination of rational and web-based bioinformatic analyses, forty-five potential antimicrobial peptides were identified, and eight of these peptides were selected to be chemically synthesized and evaluated. The successful identification of multiple novel peptides, exhibiting antibacterial properties, from Alligator mississippiensis plasma demonstrates the potential of this innovative discovery process in identifying potential new host defense peptides.

Molecular cloning and 3D model of first cytochrome P450 from CYP3A subfamily in saltwater crocodile (Crocodylus porosus).

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Tabassum, Rabia

2017-10-18

Cytochrome P450s (CYPs) play critical role in oxidative metabolism of numerous xenobiotics and endogenous compounds. The first CYP3A subfamily member in saltwater crocodile has been cloned and modelled for three-dimensional (3D) structure. The full-length cDNA was obtained employing reverse transcription polymerase chain reaction (RT-PCR) strategy and rapid amplification of cDNA ends (RACE). The cDNA sequence of 1659 nucleotides includes 132 nucleotides from 5' untranslated region (UTR), an open reading frame of 1527 nucleotides encoding 509 amino acids designated as CYP3A163. The alignment of CYP3A163 sequence with CYP3A subfamily across the lineages exhibit the loss of 1 residue in birds and 7 residues in mammals in comparison to reptiles suggesting the adaptation processes during evolution. The amino acid identity of CYP3A163 with Alligator mississippiensis CYP3A77 and Homo sapiens CYP3A4 is 91% and 62% respectively. The 3D structure of CYP3A163 modelled using human CYP3A4 structure as a template with Phyre 2 software, represents high similarity with its functionally important motifs and catalytic domain. Both sequence and structure of CYP3A163 display the common and conserved features of CYP3A subfamily. Overall, this study provides primary molecular and structural data of CYP3A163 required to investigate the xenobiotic metabolism in saltwater crocodiles. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparative serum biochemistry of captive mugger crocodiles ...

African Journals Online (AJOL)

Standard serum biochemical parameters were determined for 28 mugger crocodiles (Crocodylus palustris) using Supra-occipital plexus technique and/or Cardiocentesis technique at the Arignar Anna Zoological Park, Vandalur, Chennai, Guindy Snake Park Trust and Amaravathy Crocodile farm, Tamilnadu, India (13° 0´ N; ...

Effects of long-term corticosterone implants on growth and immune function in juvenile alligators, Alligator mississippiensis.

Science.gov (United States)

Morici, L A; Elsey, R M; Lance, V A

1997-10-01

Sixty juvenile alligators were implanted subcutaneously with slow release pellets of corticosterone or placebo. Alligators were divided into five different groups such that each group received a different dose. A blood sample was taken prior to and 4 days after the implants were in place to measure hormone levels. Additional blood samples were collected at 1 month and 3 months. At 4 days corticosterone levels ranged from 3,400 ng/ml in the group treated with the high dose to 40 ng/ml in the group implanted with the low dose. The extremely high dose caused 40% mortality within 4 weeks. It was evident that the pellets did not release the hormone for the expected 90 days. Circulating levels of corticosterone were back to baseline levels by 3 months. Hormone levels achieved at 4 days were a reliable predictor of subsequent growth. Rate of growth was negatively correlated with plasma corticosterone at 4 days (r2 = 0.711) and at 1 month (r2 = 0.544) posttreatment. Differential white blood cell counts performed after 1 month of treatment showed a clear effect of the implant. Alligators treated with corticosterone had decreased percentages of lymphocytes, eosinophils, and basophils and had a higher heterophil/lymphocyte (H/L) ratio than the placebo group. Furthermore, histological examination of the spleen revealed a significant depletion of lymphoid cells in alligators treated with the highest dose of hormone. The results from this study demonstrate that exogenous corticosterone can mimic the effects of prolonged stress in juvenile alligators.

Chronic hypoxic incubation blunts a cardiovascular reflex loop in embryonic American alligator (Alligator mississippiensis).

Science.gov (United States)

Eme, John; Hicks, James W; Crossley, Dane A

2011-10-01

Hypoxia is a naturally occurring environmental challenge for embryonic non-avian reptiles, and this study is the first to investigate the impact of chronic hypoxia on a possible chemoreflex loop in a developing non-avian reptile. We measured heart rate and blood pressure in normoxic and hypoxic-incubated (10% O(2)) American alligator embryos (Alligator mississippiensis) at 70 and 90/95% of development. We hypothesized that hypoxic incubation would blunt embryonic alligators' response to a reflex loop stimulated by phenylbiguanide (PBG), a 5-HT(3) receptor agonist that stimulates vagal pulmonary C-fiber afferents. PBG injection caused a hypotensive bradycardia in 70 and 95% of development embryos (paired t tests, P alligator, with an extended length of time between each developmental stage relative to avian species, may provide an excellent model to test the cardiorespiratory effects of prolonged exposure to changes in atmospheric gases. This extended period allows for lengthy studies at each stage without the transition to a new stage, and the natural occurrence of hypoxia and hypercapnia in crocodilian nests makes this stress ecologically and evolutionarily relevant.

OOGENESIS AND OVARIAN HISTOLOGY OF THE AMERICAN ALLIGATOR ALLIGATOR MISSISSIPPIENSIS

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Although folliculogenesis and oogenesis have been observed in numerous reptiles, these phenomena have not been described in detail in a crocodilian. Oogenesis and histological features of the adult ovary of Alligator mississippiensis are described. Using a complex process, the ov...

Movement and Home Range of Nile Crocodiles in Ndumo Game Reserve, South Africa

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Peter M. Calverley

2015-09-01

Full Text Available The study of movement patterns and home range is fundamental in understanding the spatial requirements of animals and is important in generating information for the conservation and management of threatened species. Ndumo Game Reserve, in north-eastern KwaZulu-Natal, bordering Mozambique, has the third largest Nile crocodile (Crocodylus niloticus population in South Africa. Movement patterns of 50 Nile crocodiles with a total length of between 202 cm and 472 cm were followed over a period of 18 months, using mark-resight, radio and satellite telemetry. The duration of radio transmitter attachment (131 ± 11.4 days was significantly and negatively related to total length and reproductive status. Satellite transmitters failed after an average of 15 ± 12.5 days. Home range was calculated for individuals with 10 or more radio locations, spanning a period of at least 6 months. There was a significant relationship between home range size and total length, with sub-adults (1.5 m – 2.5 m occupying smaller, more localised home ranges than adults (> 2.5 m. The largest home ranges were for adults (> 2.5 m. Home ranges overlapped extensively, suggesting that territoriality, if present, does not result in spatially discrete home ranges of Nile crocodiles in Ndumo Game Reserve during the dry season. Larger crocodiles moved farther and more frequently than smaller crocodiles. The reserve acts as a winter refuge and spring breeding site for an estimated 846 crocodiles, which also inhabit the Rio Maputo during the summer months. Nile crocodile movement out of the reserve and into the Rio Maputo starts in November and crocodiles return to the reserve as water levels in the floodplain recede in May. Conservation implications: Movement patterns of Nile crocodiles show the important role the reserve plays in the conservation of Nile crocodile populations within the greater Ndumo Game Reserve–Rio Maputo area.

Rapid suppression of testosterone secretion after capture in male American alligators (Alligator mississippiensis).

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Lance, Valentine A; Elsey, Ruth M; Butterstein, George; Trosclair, Phillip L

2004-01-15

All reptiles studied to date show an increase in circulating corticosterone following capture. This rise in corticosterone has also been shown in a number of instances to result in a decline in reproductive steroids within hours after capture. As a result of these observations it has been considered imperative to collect blood samples as soon as possible after capture to get reliable measures of reproductive hormones. It has been claimed, however, that there is no effect of capture stress on reproductive steroids in juvenile alligators held for 2 h following capture. As we generally reject blood samples that are not collected within 15 min of capture we decided to reinvestigate the effect of short-term capture (2 h) on corticosterone and testosterone in male alligators. Four groups of alligators, ranging in size from 74 to 212 cm total length were captured in a 2-week period in May, the time of year when testosterone levels are highest. Two groups were captured during the day (eight bled at capture and again at 2 h, eight bled at 2 h only) and two at night (10 bled at capture and again at 2 h, 10 bled at 2 h only). Testosterone and corticosterone in alligators bled immediately on capture and at 2 h were not significantly different in the AM and PM samples so the results were combined (Initial bleed: corticosterone, 0.95 +/- 0.09 ng/ml, n=18; testosterone, 6.06 +/- 2.09 ng/ml, n=18. Two-hour bleed: corticosterone 15.68 +/- 1.91, n=18; testosterone, 2.75 +/- 0.79, n=18). Both the increase in corticosterone and the decline in testosterone at 2 h were significant (palligators sampled only once at 2 h were not significantly different from the 2-h values in alligators sampled twice (corticosterone 15.04 +/- 1.29, n=18; testosterone, 1.85 +/- 0.62, n=18). These results clearly demonstrate that short-term capture stress results in a significant decline in testosterone in male alligators.

A Cultural Herpetology of Nile Crocodiles in Africa

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Simon Pooley

2016-01-01

Full Text Available Human-wildlife conflict is a growing problem worldwide wherever humans share landscapes with large predators, and negative encounters with eight species of the crocodilians is particularly widespread. Conservationists' responses to these adverse encounters have focused on the ecological and behavioural aspects of predators, rather than on the social, political, and cultural contexts, which have threatened their existence in the first place. Few studies have thus far tried to understand the rich, varied, contradictory, and complex relations that exist between particular humans and human societies, and particular predators and groups of predators. It is in the spirit of Brian Morris's explorations of the interactional encounters and co-produced sociabilities that exist between humans and animals in specific places and regions that this paper offers a cultural herpetology (an account of human-crocodile interrelations of the Nile crocodile (Crocodilus niloticus and C. suchus in Africa. It draws on extensive historical documentation of the interactions of humans and crocodiles across Africa to examine how diverse and complex human responses to Nile crocodiles have been, and continue to be, and suggests some implications for improving human-crocodile relations.

Riparian vegetation structure and the hunting behavior of adult estuarine crocodiles.

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Luke J Evans

Full Text Available Riparian ecosystems are amongst the most biodiverse tropical habitats. They are important, and essential, ecological corridors, linking remnant forest fragments. In this study, we hypothesised that crocodile's actively select nocturnal resting locations based on increased macaque predation potential. We examined the importance of riparian vegetation structure in the maintenance of crocodile hunting behaviours. Using airborne Light Detection and Ranging (LiDAR and GPS telemetry on animal movement, we identified the repeated use of nocturnal resting sites by adult estuarine crocodiles (Crocodylus porosus throughout the fragmented Lower Kinabatangan Wildlife Sanctuary in Sabah, Malaysia. Crocodile resting locations were found to resemble, in terms of habitat characteristics, the sleeping sites of long-tailed macaque; positioned in an attempt to avoid predation by terrestrial predators. We found individual crocodiles were actively selecting overhanging vegetation and that the protrusion of trees from the tree line was key to site selection by crocodiles, as well as influencing both the presence and group size of sleeping macaques. Although these findings are correlational, they have broad management implications, with the suggestion that riparian corridor maintenance and quality can have implications beyond that of terrestrial fauna. We further place our findings in the context of the wider ecosystem and the maintenance of trophic interactions, and discuss how future habitat management has the potential to mitigate human-wildlife conflict.

Effects of prolonged lung inflation or deflation on pulmonary stretch receptor discharge in the alligator (Alligator mississippiensis).

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Marschand, Rachel E; Wilson, Jenna L; Burleson, Mark L; Crossley, Dane A; Hedrick, Michael S

2014-08-15

The American alligator (Alligator mississippiensis) is a semi-aquatic diving reptile that has a periodic breathing pattern. Previous work identified pulmonary stretch receptors, that are rapidly and slowly adapting, as well as intrapulmonary chemoreceptors (IPC), sensitive to CO2, that modulate breathing patterns in alligators. The purpose of the present study was to quantify the effects of prolonged lung inflation and deflation (simulated dives) on pulmonary stretch receptors (PSR) and/or IPC discharge characteristics. The effects of airway pressure (0-20 cm H2O), hypercapnia (7% CO2), and hypoxia (5% O2) on dynamic and static responses of PSR were studied in juvenile alligators (mean mass=246 g) at 24°C. Alligators were initially anesthetized with isoflurane, cranially pithed, tracheotomized and artificially ventilated. Vagal afferent tonic and phasic activity was recorded with platinum hook electrodes. Receptor activity was a mixture of slowly adapting PSR (SAR) and rapidly adapting PSR (RAR) with varying thresholds and degrees of adaptation, without CO2 sensitivity. Receptor activity before, during and after 1 min periods of lung inflation and deflation was quantified to examine the effect of simulated breath-hold dives. Some PSR showed a change in dynamic response, exhibiting inhibition for several breaths after prolonged lung inflation. Following 1 min deflation, RAR, but not SAR, exhibited a significant potentiation of burst frequency relative to control. For SAR, the post-inflation receptor inhibition was blocked by CO2 and hypoxia; for RAR, the post-inflation inhibition was potentiated by CO2 and blocked by hypoxia. These results suggest that changes in PSR firing following prolonged inflation and deflation may promote post-dive ventilation in alligators. We hypothesize that PSR in alligators may be involved in recovery of breathing patterns and lung volume during pre- and post-diving behavior and apneic periods in diving reptiles. Copyright © 2014

Crocodile jaw sign

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Brij Sharma

2016-01-01

Full Text Available This teaching image highlights the CT abdominal imaging finding of 'crocodile jaw sign' which should raise concern about the presence of an incomplete annular pancreas which causes partial encasement of the duodenum.

The Federal Government and the Alligator Rivers Region

International Nuclear Information System (INIS)

BURTON, A.

1989-01-01

The administrative framework put in place by the Commonwealth and Northern Territory governments to monitor mining activities in the Alligator Rivers Region is presented. The key institutional element is the Coordinating Committee for the Alligator Rivers Region chaired and serviced by the Supervising Scientist and established through legislation

'A pond with crocodiles never dries up’: a frame analysis of human-crocodile relationships in agro-pastoral dams in Northern Benin

NARCIS (Netherlands)

Kpéra, G.N.; Aarts, N.; Tossou, R.C.; Mensah, G.A.; Saïdou, A.; Kossou, D.K.; Sinsin, A.B.; van der Zijpp, A.J.

2014-01-01

Crocodiles, a protected species, share ecosystem services with local communities in agro-pastoral dams in Northern Benin. Using a comparative case study conducted in three villages and a framing perspective, this study aims to elucidate how stakeholders frame the presence of crocodiles, and how they

Hexavalent chromium is cytotoxic and genotoxic to American alligator cells.

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Wise, Sandra S; Wise, Catherine; Xie, Hong; Guillette, Louis J; Zhu, Cairong; Wise, John Pierce; Wise, John Pierce

2016-02-01

Metals are a common pollutant in the aquatic ecosystem. With global climate change, these levels are anticipated to rise as lower pH levels allow sediment bound metals to be released. The American alligator (Alligator mississippiensis) is an apex predator in the aquatic ecosystem and is considered a keystone species; as such it serves as a suitable monitor for localized pollution. One metal of increasing concern is hexavalent chromium (Cr(VI)). It is present in the aquatic environment and is a known human carcinogen and reproductive toxicant. We measured the cytotoxicity and genotoxicity of Cr(VI) in American alligator cells derived from scute tissue. We found that particulate and soluble Cr(VI) are both cytotoxic and genotoxic to alligator cells in a concentration-dependent manner. These data suggest that alligators may be used as a model for assessing the effects of environmental Cr(VI) contamination as well as for other metals of concern. Copyright © 2015 Elsevier B.V. All rights reserved.

Spatial and temporal variability in estuary habitat use by American alligators

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Fujisaki, Ikuko; Hart, Kristen M.; Cherkiss, Michael S.; Mazzotti, Frank J.; Beauchamp, Jeffrey S.; Jeffery, Brian M.; Brandt, Laura A.

2016-01-01

Estuarine habitat occupied by Alligator mississippiensis, a primarily freshwater species, is spatially and temporally heterogeneous largely due to a salinity gradient that fluctuates. Using long-term night light survey data, we examined seasonal patterns in alligators’ habitat use by size classes in midstream and downstream estuary zones of Shark River, Everglades National Park, in southern Florida. We observed predominantly large-sized alligators (total length ≥ 1.75 m); observations of alligators in the small size classes (0.5 m ≤ total length freshwater wetlands. Our results indicated high adaptability of alligators to the fluctuating habitat conditions. Use of estuaries by alligators is likely driven in part by physiology and possibly by reproductive cycle, and our results supported their opportunistic use of estuary habitat and ontogenetic niche shifts.

Assessment of Captive Management of Nile Crocodile, Crocodylus ...

African Journals Online (AJOL)

The number of crocodiles and the number of eggs were of the constraints faced in managing them in captivity. The constraints mentioned includes inadequate space (75%) and inadequate funds (62.5%). Others includes problems of water, fighting among the crocodiles, diseases and parasites. The main recommendation is ...

Comparison of metabolic substrates in alligators and several birds of prey.

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Sweazea, Karen L; McMurtry, John P; Elsey, Ruth M; Redig, Patrick; Braun, Eldon J

2014-08-01

On average, avian blood glucose concentrations are 1.5-2 times those of mammals of similar mass and high concentrations of insulin are required to lower blood glucose. Whereas considerable data exist for granivorous species, few data are available for plasma metabolic substrate and glucoregulatory hormone concentrations for carnivorous birds and alligators. Birds and mammals with carnivorous diets have higher metabolic rates than animals consuming diets with less protein whereas alligators have low metabolic rates. Therefore, the present study was designed to compare substrate and glucoregulatory hormone concentrations in several birds of prey and a phylogenetically close relative of birds, the alligator. The hypothesis was that the combination of carnivorous diets and high metabolic rates favored the evolution of greater protein and fatty acid utilization leading to insulin resistance and high plasma glucose concentrations in carnivorous birds. In contrast, it was hypothesized that alligators would have low substrate utilization attributable to a low metabolic rate. Fasting plasma substrate and glucoregulatory hormone concentrations were compared for bald eagles (Haliaeetus leucocephalus), great horned owls (Bubo virginianus), red-tailed hawks (Buteo jamaicensis), and American alligators (Alligator mississippiensis). Avian species had high circulating β-hydroxybutyrate (10-21 mg/dl) compared to alligators (2.81 ± 0.16 mg/dl). In mammals high concentrations of this byproduct of fatty acid utilization are correlated with insulin resistance. Fasting glucose and insulin concentrations were positively correlated in eagles whereas no relationship was found between these variables for owls, hawks or alligators. Additionally, β-hydroxybutyrate concentrations were low in alligators. Similar to carnivorous mammals, ingestion of a high protein diet may have favored the utilization of fatty acids and protein for energy thereby promoting the development of insulin

METALS AND METALLOIDS IN TISSUES OF AMERICAN ALLIGATORS IN THREE FLORIDA LAKES

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Concentrations of metals and selenium were examined in tissues of American alligators (Alligator mississippiensis) from three lakes in central Florida, in one of which alligators have exhibited reproductive or developmental defects. Our overall objective was to determine whether ...

Fluctuating water depths affect American alligator (Alligator mississippiensis) body condition in the Everglades, Florida, USA

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Brandt, Laura A.; Beauchamp, Jeffrey S.; Jeffery, Brian M.; Cherkiss, Michael S.; Mazzotti, Frank J.

2016-01-01

Successful restoration of wetland ecosystems requires knowledge of wetland hydrologic patterns and an understanding of how those patterns affect wetland plant and animal populations.Within the Everglades, Florida, USA restoration, an applied science strategy including conceptual ecological models linking drivers to indicators is being used to organize current scientific understanding to support restoration efforts. A key driver of the ecosystem affecting the distribution and abundance of organisms is the timing, distribution, and volume of water flows that result in water depth patterns across the landscape. American alligators (Alligator mississippiensis) are one of the ecological indicators being used to assess Everglades restoration because they are a keystone species and integrate biological impacts of hydrological operations through all life stages. Alligator body condition (the relative fatness of an animal) is one of the metrics being used and targets have been set to allow us to track progress. We examined trends in alligator body condition using Fulton’s K over a 15 year period (2000–2014) at seven different wetland areas within the Everglades ecosystem, assessed patterns and trends relative to restoration targets, and related those trends to hydrologic variables. We developed a series of 17 a priori hypotheses that we tested with an information theoretic approach to identify which hydrologic factors affect alligator body condition. Alligator body condition was highest throughout the Everglades during the early 2000s and is approximately 5–10% lower now (2014). Values have varied by year, area, and hydrology. Body condition was positively correlated with range in water depth and fall water depth. Our top model was the “Current” model and included variables that describe current year hydrology (spring depth, fall depth, hydroperiod, range, interaction of range and fall depth, interaction of range and hydroperiod). Across all models, interaction

Determinants of habitat selection by hatchling Australian freshwater crocodiles.

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Ruchira Somaweera

Full Text Available Animals almost always use habitats non-randomly, but the costs and benefits of using specific habitat types remain unknown for many types of organisms. In a large lake in northwestern Australia (Lake Argyle, most hatchling (<12-month-old freshwater crocodiles (Crocodylus johnstoni are found in floating vegetation mats or grassy banks rather than the more widely available open banks. Mean body sizes of young crocodiles did not differ among the three habitat types. We tested four potential explanations for non-random habitat selection: proximity to nesting sites, thermal conditions, food availability, and exposure to predation. The three alternative habitat types did not differ in proximity to nesting sites, or in thermal conditions. Habitats with higher food availability harboured more hatchlings, and feeding rates (obtained by stomach-flushing of recently-captured crocodiles were highest in such areas. Predation risk may also differ among habitats: we were twice as likely to capture a crocodile after seeing it in open-bank sites than in the other two habitat types. Thus, habitat selection of hatchling crocodiles in this system may be driven both by prey availability and by predation risk.

'A pond with crocodiles never dries up'. A frame analysis of human –crocodile relationships in agro-pastoral dams in Northern Benin

NARCIS (Netherlands)

Kpera, G.N.; Aarts, N.; Tossou, R.C.; Mensah, G.A.; Saïdou, A.; Kossou, D.K.; Sinsin, A.B.; Zijpp, van der A.J.

2014-01-01

Crocodiles, a protected species, share ecosystem services with local communities in agro-pastoral dams in Northern Benin. Using a comparative case study conducted in three villages and a framing perspective, this study aims to elucidate how stakeholders frame the presence of crocodiles, and how they

Diets Alter the Gut Microbiome of Crocodile Lizards

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Hai-Ying Jiang

2017-10-01

Full Text Available The crocodile lizard is a critically endangered reptile, and serious diseases have been found in this species in recent years, especially in captive lizards. Whether these diseases are caused by changes in the gut microbiota and the effect of captivity on disease remains to be determined. Here, we examined the relationship between the gut microbiota and diet and disease by comparing the fecal microbiota of wild lizards with those of sick and healthy lizards in captivity. The gut microbiota in wild crocodile lizards was consistently dominated by Proteobacteria (∼56.4% and Bacteroidetes (∼19.1%. However, the abundance of Firmicutes (∼2.6% in the intestine of the wild crocodile lizards was distinctly lower than that in other vertebrates. In addition, the wild samples from Guangdong Luokeng Shinisaurus crocodilurus National Nature Reserve also had a high abundance of Deinococcus–Thermus while the wild samples from Guangxi Daguishan Crocodile Lizard National Nature Reserve had a high abundance of Tenericutes. The gut microbial community in loach-fed crocodile lizards was significantly different from the gut microbial community in the earthworm-fed and wild lizards. In addition, significant differences in specific bacteria were detected among groups. Notably, in the gut microbiota, the captive lizards fed earthworms resulted in enrichment of Fusobacterium, and the captive lizards fed loaches had higher abundances of Elizabethkingia, Halomonas, Morganella, and Salmonella, all of which are pathogens or opportunistic pathogens in human or other animals. However, there is no sufficient evidence that the gut microbiota contributes to either disease A or disease B. These results provide a reference for the conservation of endangered crocodile lizards and the first insight into the relationship between disease and the gut microbiota in lizards.

Molecular identification of Indian crocodile species: PCR-RFLP method for forensic authentication*.

Science.gov (United States)

Meganathan, P R; Dubey, Bhawna; Haque, Ikramul

2009-09-01

South East Asian countries are known for illegal poaching and trade of crocodiles clandestinely, to be used in skin, medicinal, and cosmetic industries. Besides crocodiles being listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora, India has its Wildlife Protection Act, 1972 for conservation of crocodile species. Hitherto, lack of any rapid and reliable technique for examinations of crocodile-based crime exhibits such as skin, bones, etc. has been a major problem for an effective promulgation of law on illegal trade. DNA-based identification of species using PCR-RFLP technique for an apt identification of all the three Indian crocodile species namely, Crocodylus porosus, Crocodylus palustris and Gavialis gangeticus is presented here. A 628 bp segment of cytochrome b gene was amplified using novel primers followed by restriction digestion with three enzymes i.e., HaeIII, MboI, and MwoI, separately and in combination. The technique has produced a species-specific pattern for identifying the three crocodile species individually, which fulfills the requirement for its forensic application. It is expected that the technique will prove handy in identification of all the three Indian crocodile species and strengthen conservation efforts.

Normal haematology and blood biochemistry of wild Nile crocodiles (Crocodylus niloticus in the Okavango Delta, Botswana

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C.J. Lovely

2007-06-01

Full Text Available Wild Nile crocodiles (Crocodylus niloticus of various size classes were captured in the Okavango Delta, Botswana. Blood was collected from the post occipital sinus and used for the determination of a wide range of haematological and biochemical parameters. These values were compared between the sexes and between 3 size classes. The values were also compared with the limited data available from farmed Nile crocodiles, as well as from other wild Nile crocodiles. The Okavango crocodiles were comparatively anaemic, and had comparatively low total protein and blood glucose levels. There was a high prevalence of Hepatozoon pettiti infection, however, there was no significant difference in haematological values between the infected and uninfected crocodiles. The values reported here will be useful in diagnostic investigations in both zoo and farmed Nile crocodiles.

Analysis of PFAAs in American alligators part 2: Potential dietary exposure of South Carolina hunters from recreationally harvested alligator meat.

Science.gov (United States)

Tipton, Jessica J; Guillette, Louis J; Lovelace, Susan; Parrott, Benjamin B; Rainwater, Thomas R; Reiner, Jessica L

2017-11-01

Exposure to perfluorinated alkyl acids (PFAAs) has been linked to many harmful health effects including reproductive disorders, developmental delays, and altered liver and kidney function. Most human exposure to environmental contaminants, including PFAAs, occurs through consumption of contaminated food or drinking water. This study uses PFAA data from meat samples collected from recreationally harvested American alligators (Alligator mississippiensis) in South Carolina to assess potential dietary exposure of hunters and their families to PFAAs. Consumption patterns were investigated using intercept surveys of 23 hunters at a wild game meat processor. An exposure scenario using the average consumption frequency, portion size, and median perfluorooctane sulfonic acid (PFOS) concentration in alligator meat from all hunt units found the daily dietary exposure to be 2.11ng/kg body weight per day for an adult human. Dietary PFOS exposure scenarios based on location of harvest suggested the highest daily exposure occurs with alligator meat from the Middle Coastal hunt unit in South Carolina. Although no samples were found to exceed the recommended threshold for no consumption of PFOS found in Minnesota state guidelines, exposure to a mixture of PFAAs found in alligator meat and site-specific exposures based on harvest location should be considered in determining an appropriate guideline for vulnerable populations potentially exposed to PFAAs through consumption of wild alligator meat. Copyright © 2017. Published by Elsevier B.V.

Environmental protection in the Alligator Rivers Region

International Nuclear Information System (INIS)

Riley, G.

1989-01-01

One of a series of articles on the work of the Office of the Supervising Scientist for the Alligator Rivers Region (OSS) and its Alligator Rivers Region Research Institute (ARRRI), this discusses the environmental protection function of the OSS and the role of the ARRRI in achieving this

Tõeline Crocodile Dundee / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2006-01-01

4. sept. hukkus veealuse dokfilmi võtetel Austraalia loodusuurija, loomakaitsja, telekanali Animal Planet sarja "Krokodillikütt" ("Crocodile Hunter") populaarne autor ja esineja Steve Irwin (1962-2006)

Determinants of Habitat Selection by Hatchling Australian Freshwater Crocodiles

Science.gov (United States)

Somaweera, Ruchira; Webb, Jonathan K.; Shine, Richard

2011-01-01

Animals almost always use habitats non-randomly, but the costs and benefits of using specific habitat types remain unknown for many types of organisms. In a large lake in northwestern Australia (Lake Argyle), most hatchling (banks rather than the more widely available open banks. Mean body sizes of young crocodiles did not differ among the three habitat types. We tested four potential explanations for non-random habitat selection: proximity to nesting sites, thermal conditions, food availability, and exposure to predation. The three alternative habitat types did not differ in proximity to nesting sites, or in thermal conditions. Habitats with higher food availability harboured more hatchlings, and feeding rates (obtained by stomach-flushing of recently-captured crocodiles) were highest in such areas. Predation risk may also differ among habitats: we were twice as likely to capture a crocodile after seeing it in open-bank sites than in the other two habitat types. Thus, habitat selection of hatchling crocodiles in this system may be driven both by prey availability and by predation risk. PMID:22163308

In vitro drug susceptibility pattern of Mycoplasma alligatoris isolated from symptomatic American alligators (Alligator mississippiensis).

Science.gov (United States)

Helmick, Kelly E; Brown, Daniel R; Jacobson, Elliott R; Brown, Mary B

2002-06-01

A recently described mycoplasma, Mycoplasma alligatoris, was isolated from dead American alligators (Alligator mississippiensis) that had demonstrated clinical signs of lethargy, anorexia, bilateral ocular discharge, edema. paraparesis, and polyarthritis. The in vitro minimum inhibitory concentration for nine antibacterial agents was determined through serial dilution in broth and plate culture for M. alligatoris isolates. The inhibitory concentration obtained for doxycycline, enrofloxacin, sarafloxacin, oxytetracycline, tilmicosin, and tylosin (< 1 microg/ml) was lower than that of clindamycin (1-8 microg/ml), chloramphenicol (8-16 microg/ml), and erythromycin (32-138 microg/ml).

An 11-digit identification system for individual Nile crocodiles using natural markings

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Hindrik Bouwman

2016-05-01

Full Text Available Research and conservation of wild crocodiles and husbandry of captive crocodiles requires the reliable identification of individuals. We present a method using the individual colour markings on the first 10 single-crest scutes on the tails of Nile crocodiles (Crocodylus niloticus. The scutes are scored by number for colour, with a prefix for left or right providing a binary 11-digit identification number (identification numbers [IDs]; e.g. 12232232242 and 22333233232 per crocodile. A survey of 359 captive Nile crocodiles showed no duplication. However, 42% had asymmetrical scute markings requiring a binary approach. There does not seem to be a change in patterns with age, except that the number of missing scutes increased. A small trial showed that this method can be applied in the field, although more work is needed to determine observer bias and establish parameters for observability in the field. It is unlikely that both left and right IDs would be obtainable for each individual, but other distinctive markings such as scute shape and damage can be used to register the two IDs to one individual. Having two independent IDs for each crocodile provides the possibility of two independent population estimates for equal effort without having to link left and right IDs to individuals. Our proposed method would be useful in conservation, individual tracking and husbandry. Conservation implications: A non-invasive marking and recapture method for Nile crocodile is presented whereby the first 10 single-crest scutes are scored for colour, allowing conservation practitioners to count and monitor crocodile populations and individuals. This method provides two equal-effort estimations of population size, as left and right hand sides are scored independently. Keywords: Crocodylus niloticus; identification; mark - recapture; mark - resight

Seasonal Variation of Total Mercury Burden in the American Alligator (Alligator Mississippiensis) at Merritt Island National Wildlife Refuge (MINWR), Florida

Science.gov (United States)

Nilsen, Frances M.; Dorsey, Jonathan E.; Long, Stephen E.; Schock, Tracey B.; Bowden, John A.; Lowers, Russell H.; Guillette, Louis J., Jr.

2016-01-01

Seasonal variation of mercury (Hg) is not well studied in free-ranging wildlife. Atmospheric deposition patterns of Hg have been studied in detail and have been modeled for both global and specific locations with great accuracy and correlates to environment impact. However, monitoring these trends in wildlife is complicated due to local environmental parameters (e.g., rainfall, humidity, pH, bacterial composition) that can affect the transformation of atmospheric Hg to the biologically available forms. Here, we utilized an abundant and healthy population of American alligators (Alligator mississippiensis) at Merritt Island National Wildlife Refuge (MINWR), FL, and assessed Hg burden in whole blood samples over a span of 7 years (2007 2014; n 174) in an effort to assess seasonal variation of total [Hg]. While the majority of this population is assumed healthy, 18 individuals with low body mass indices (BMI, defined in this study) were captured throughout the 7 year sampling period. These individual alligators exhibited [Hg] that were not consistent with the observed overall seasonal [Hg] variation, and were statistically different from the healthy population of alligators. The alligators with low BMI had elevated concentrations of Hg compared to their age/sex/season matched counterparts with normal BMI. Statistically significant differences were found between the winter and spring seasons for animals with normal BMI. The data in this report supports the conclusion that organismal total [Hg] do fluctuate directly with seasonal deposition rates as well as other seasonal environmental parameters, such as average rainfall and prevailing wind direction. This study highlights the unique environment of MINWR to permit annual assessment of apex predators, such as the American alligator, to determine detailed environmental impact of contaminants of concern.

Mechanics of fragmentation of crocodile skin and other thin films

Science.gov (United States)

Qin, Zhao; Pugno, Nicola M.; Buehler, Markus J.

2014-01-01

Fragmentation of thin layers of materials is mediated by a network of cracks on its surface. It is commonly seen in dehydrated paintings or asphalt pavements and even in graphene or other two-dimensional materials, but is also observed in the characteristic polygonal pattern on a crocodile's head. Here, we build a simple mechanical model of a thin film and investigate the generation and development of fragmentation patterns as the material is exposed to various modes of deformation. We find that the characteristic size of fragmentation, defined by the mean diameter of polygons, is strictly governed by mechanical properties of the film material. Our result demonstrates that skin fragmentation on the head of crocodiles is dominated by that it features a small ratio between the fracture energy and Young's modulus, and the patterns agree well with experimental observations. Understanding this mechanics-driven process could be applied to improve the lifetime and reliability of thin film coatings by mimicking crocodile skin. PMID:24862190

Mechanics of fragmentation of crocodile skin and other thin films

Science.gov (United States)

Qin, Zhao; Pugno, Nicola M.; Buehler, Markus J.

2014-05-01

Fragmentation of thin layers of materials is mediated by a network of cracks on its surface. It is commonly seen in dehydrated paintings or asphalt pavements and even in graphene or other two-dimensional materials, but is also observed in the characteristic polygonal pattern on a crocodile's head. Here, we build a simple mechanical model of a thin film and investigate the generation and development of fragmentation patterns as the material is exposed to various modes of deformation. We find that the characteristic size of fragmentation, defined by the mean diameter of polygons, is strictly governed by mechanical properties of the film material. Our result demonstrates that skin fragmentation on the head of crocodiles is dominated by that it features a small ratio between the fracture energy and Young's modulus, and the patterns agree well with experimental observations. Understanding this mechanics-driven process could be applied to improve the lifetime and reliability of thin film coatings by mimicking crocodile skin.

Stress-induced suppression of testosterone secretion in male alligators.

Science.gov (United States)

Lance, V A; Elsey, R M

1986-08-01

In order to test the effect of acute stress on gonadal hormone secretion in reptiles, six mature male alligators were captured, and a blood sample was taken within 5 min of capture. Additional blood samples were taken at timed intervals for up to 41 hr, and plasma testosterone and corticosterone were measured by radioimmunoassay. Plasma testosterone declined to 50% of the initial value by 4 hr and dropped to less than 10% of initial by 24 hr. Plasma corticosterone increased during the first 12 hr, declined at 24 hr, and rose again at 40 hr. Blood samples from male alligators collected in North and South Carolina, south Florida, and in south Louisiana in two consecutive breeding seasons were also assayed for testosterone and corticosterone. In these populations there were significant differences in mean plasma testosterone and corticosterone levels. Elevated corticosterone levels were consistently seen in alligators caught in traps and from which a blood sample was taken several hours later. Plasma testosterone, although consistently lower in trapped alligators, did not show a negative correlation with plasma corticosterone. Farm-reared alligators bled once, released, and bled again at 24 hr also showed a highly significant suppression of testosterone secretion. These results demonstrate that stress has a rapid and dramatic effect on testicular steroid secretion in both farm-reared and wild alligators.

Antibacterial activity of plasma from crocodile (Crocodylus siamensis against pathogenic bacteria

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Kommanee Jintana

2012-07-01

Full Text Available Abstract Background The Siamese crocodile (Crocodylus siamensis is a critically endangered species of freshwater crocodiles. Crocodilians live with opportunistic bacterial infection but normally suffer no adverse effects. They are not totally immune to microbial infection, but their resistance thereto is remarkably effective. In this study, crude and purified plasma extracted from the Siamese crocodile were examined for antibacterial activity against clinically isolated, human pathogenic bacterial strains and the related reference strains. Methods Crude plasma was prepared from whole blood of the Siamese crocodile by differential sedimentation. The crude plasma was examined for antibacterial activity by the liquid growth inhibition assay. The scanning electron microscopy was performed to confirm the effect of crude crocodile plasma on the cells of Salmonella typhi ATCC 11778. Effect of crude crocodile plasma on cell viability was tested by MTT assay. In addition, the plasma was purified by anion exchange column chromatography with DEAE-Toyopearl 650 M and the purified plasma was tested for antibacterial activity. Results Crude plasma was prepared from whole blood of the Siamese crocodile and exhibited substantial antibacterial activities of more than 40% growth inhibition against the six reference strains of Staphylococcus aureus, Salmonella typhi, Escherichia coli, Vibrio cholerae, Pseudomonas aeruginosa, and Staphylococcus epidermidis, and the four clinical isolates of Staphylococcus epidermidis, Pseudomonas aeruginosa, Salmonella typhi, and Vibrio cholerae. Especially, more than 80% growth inhibition was found in the reference strains of Salmonella typhi, Vibrio cholerae, and Staphylococcus epidermidis and in the clinical isolates of Salmonella typhi and Vibrio cholerae. The effect of the crude plasma on bacterial cells of Salmonella typhi, a certain antibacterial material probably penetrates progressively into the cytoplasmic space

An outbreak of chlamydiosis in farmed Indopacific crocodiles (Crocodylus porosus : clinical communication

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F.W. Huchzermeyer

2008-05-01

Full Text Available An outbreak of chlamydiosis was diagnosed in hatchling and juvenile Indopacific crocodiles (Crocodylus porosus on a crocodile farm in Papua New Guinea. The outbreak was characterised by high mortality with hepatitis and exudative conjunctivitis. The agent appears to have been introduced with live wild-caught crocodiles, which are purchased routinely by the farm. Improved quarantine procedures and treatment with tetracycline led to a rapid reduction of losses on the farm.

Effects of feeding on arterial blood gases in the American alligator Alligator mississippiensis.

Science.gov (United States)

Busk, M; Overgaard, J; Hicks, J W; Bennett, A F; Wang, T

2000-10-01

Reptiles habitually ingest large meals at infrequent intervals, leading to changes in acid-base status as the net secretion of acid to the stomach causes a metabolic alkalosis (the alkaline tide). In chronically cannulated and undisturbed amphibians and reptiles, the pH changes in arterial blood are, nevertheless, reduced by a concomitant respiratory acidosis (increased P(CO2) caused by a relative hypoventilation). Alligators (Alligator mississippiensis) have been reported to exhibit exceptionally large increases in plasma [HCO3(-)] following feeding, but these studies were based on blood samples obtained by cardiac puncture, so stress and disturbance may have affected the blood gas levels. Furthermore, crocodilian haemoglobin is characterised by a unique binding of HCO3(-) that act to reduce blood oxygen-affinity, and it has been proposed that this feature safeguards oxygen offloading by counteracting pH effects on blood oxygen-affinity. Therefore, to study acid-base regulation and the interaction between the alkaline tide and oxygen transport in more detail, we describe the arterial blood gas composition of chronically cannulated and undisturbed alligators before and after voluntary feeding (meal size 7.5+/-1% of body mass). Digestion was associated with an approximately fourfold increase in metabolic rate (from 0.63+/-0.04 to 2.32+/-0.24 ml O(2) min(-1)kg(-1)) and was accompanied by a small increase in the respiratory gas exchange ratio. The arterial P(O2) of fasting alligators was 60.3+/-6.8 mmHg (1 mmHg = 0.133 kPa) and reached a maximum of 81.3+/-2.7 mmHg at 96 h following feeding; there was only a small increase in lactate levels, so the increased metabolic rate seems to be entirely aerobic. Plasma [HCO3(-)] increased from 24.4+/-1.1 to 36.9+/-1.7 mmol l(-1) (at 24 h), but since arterial P(CO2) increased from 29.0+/-1.1 to 36.8+/-1.3 mmHg, arterial pH remained virtually unaffected (changing from 7.51+/-0.01 to 7.58+/-0.01 at 24 h). The changes in plasma [HCO

Thermoregulatory adaptations and heat energy budget analyses of the American alligator, Alligator mississippiensis

Energy Technology Data Exchange (ETDEWEB)

Terpin, Kenneth M. [Univ. at Buffalo, NY (United States)

1976-01-01

Wild alligators were acclimated to laboratory conditions and thermocouples were surgically implanted at seven locations in the body. Animals were tested at different steady state environmental conditions in a climate space simulation chamber in order to ascertain the effect of heat transfer on body temperature. Results are reported.

Spatial and stage-structured population model of the American crocodile for comparison of comprehensive Everglades Restoration Plan (CERP) alternatives

Science.gov (United States)

Green, Timothy W.; Slone, Daniel H.; Swain, Eric D.; Cherkiss, Michael S.; Lohmann, Melinda; Mazzotti, Frank J.; Rice, Kenneth G.

2010-01-01

As part of the U.S. Geological Survey Priority Ecosystems Science (PES) initiative to provide the ecological science required during Everglades restoration, we have integrated current regional hydrologic models with American crocodile (Crocodylus acutus) research and monitoring data to create a model that assesses the potential impact of Comprehensive Everglades Restoration Plan (CERP) efforts on the American crocodile. A list of indicators was created by the Restoration Coordination and Verification (RECOVER) component of CERP to help determine the success of interim restoration goals. The American crocodile was established as an indicator of the ecological condition of mangrove estuaries due to its reliance upon estuarine environments characterized by low salinity and adequate freshwater inflow. To gain a better understanding of the potential impact of CERP restoration efforts on the American crocodile, a spatially explicit crocodile population model has been created that has the ability to simulate the response of crocodiles to various management strategies for the South Florida ecosystem. The crocodile model uses output from the Tides and Inflows in the Mangroves of the Everglades (TIME) model, an application of the Flow and Transport in a Linked Overland/Aquifer Density Dependent System (FTLOADDS) simulator. TIME has the capability to link to the South Florida Water Management Model (SFWMM), which is the primary regional tool used to assess CERP restoration scenarios. A crocodile habitat suitability index and spatial parameter maps that reflect salinity, water depth, habitat, and nesting locations are used as driving functions to construct crocodile finite rate of increase maps under different management scenarios. Local stage-structured models are integrated with a spatial landscape grid to display crocodile movement behavior in response to changing environmental conditions. Restoration efforts are expected to affect salinity levels throughout the habitat of

Body condition of Morelet’s Crocodiles (Crocodylus moreletii) from northern Belize

Science.gov (United States)

Mazzotti, Frank J.; Cherkiss, Michael S.; Brandt, Laura A.; Fujisaki, Ikuko; Hart, Kristen; Jeffery, Brian; McMurry, Scott T.; Platt, Steven G.; Rainwater, Thomas R.; Vinci, Joy

2012-01-01

Body condition factors have been used as an indicator of health and well-being of crocodilians. We evaluated body condition of Morelet's Crocodiles (Crocodylus moreletii) in northern Belize in relation to biotic (size, sex, and habitat) and abiotic (location, water level, and air temperature) factors. We also tested the hypothesis that high water levels and warm temperatures combine or interact to result in a decrease in body condition. Size class, temperature, and water level explained 20% of the variability in condition of Morelet's Crocodiles in this study. We found that adult crocodiles had higher condition scores than juveniles/subadults but that sex, habitat, and site had no effect. We confirmed our hypothesis that warm temperatures and high water levels interact to decrease body condition. We related body condition of Morelet's Crocodiles to natural fluctuations in air temperatures and water levels in northern Belize, providing baseline conditions for population and ecosystem monitoring.

Check-list of the pentastomid parasites crocodilians and freshwater chelonians.

Science.gov (United States)

Junker, K; Boomker, J

2006-03-01

Based on published records and own data a summary is given of the geographical distribution of the currently known species of pentastomid parasites infecting crocodiles and alligators, as well as freshwater chelonians. A brief generic diagnosis is provided for each genus. Fourteen out of the currently 23 living crocodilian species have been recorded as being host to one or more pentastomes. Out of the 32 pentastome species six are considered species inquirendae. Presently, six genera of crocodilian pentastomes, Agema, Alofia, Leiperia, Sebekia, Selfia and Subtriquetra are recognized. African crocodiles harbour eight pentastome species, six of which have been recorded from the Nile crocodile, Crocodylus niloticus. Three species belong to the genus Sebekia, Alofia being represented by two and Leiperia by only one species. Two species, Alofia parva and Agema silvae-palustris, occur in the dwarf crocodile, Osteolaemus tetraspis, and the slender-snouted crocodile, Crocodylus cataphractus, exclusively, but a single Sebekia species is shared with the Nile crocodile. The genus Agema is endemic to the African region. Infective stages of the pentastome Subtriquetra rileyi, thought to utilize Nile crocodiles as final hosts, have been recovered only from fishes. The largest number of pentastome species is found in the Australasian region. Of these, the Indo-Pacific crocodile, Crocodylus porosus, harbours seven, representing the genera Alofia, Sebekia, Leiperia and Selfia. Selfia is exclusive to the latter host. The genus Subtriquetra has been reported from "Indian crocodiles", a term possibly referring to either Crocodylus palustris, Crocodylus porosus or Gavialis gangeticus. Ten species of pentastomes parasitizing the crocodilian genera Alligator, Caiman, Crocodylus and Melanosuchus have been recorded from the Neotropical region including the southern states of the North American continent. The two most wide-spread pentastome genera, Alofia and Sebekia, have been recorded

Swallowed by a cayman : integrating cultural values in Philippine crocodile conservation

NARCIS (Netherlands)

Ploeg, Johan van der (Jan)

2013-01-01

The Philippine crocodile is a critically endangered species, endemic to the Philippine Islands. Indiscriminate hunting, the use of destructive fishing practices and the conversion of wetland habitat into rice fields continue to threaten the few remaining Philippine crocodile populations in the wild.

Scale-Dependent Habitat Selection and Size-Based Dominance in Adult Male American Alligators.

Directory of Open Access Journals (Sweden)

Bradley A Strickland

Full Text Available Habitat selection is an active behavioral process that may vary across spatial and temporal scales. Animals choose an area of primary utilization (i.e., home range then make decisions focused on resource needs within patches. Dominance may affect the spatial distribution of conspecifics and concomitant habitat selection. Size-dependent social dominance hierarchies have been documented in captive alligators, but evidence is lacking from wild populations. We studied habitat selection for adult male American alligators (Alligator mississippiensis; n = 17 on the Pearl River in central Mississippi, USA, to test whether habitat selection was scale-dependent and individual resource selectivity was a function of conspecific body size. We used K-select analysis to quantify selection at the home range scale and patches within the home range to determine selection congruency and important habitat variables. In addition, we used linear models to determine if body size was related to selection patterns and strengths. Our results indicated habitat selection of adult male alligators was a scale-dependent process. Alligators demonstrated greater overall selection for habitat variables at the patch level and less at the home range level, suggesting resources may not be limited when selecting a home range for animals in our study area. Further, diurnal habitat selection patterns may depend on thermoregulatory needs. There was no relationship between resource selection or home range size and body size, suggesting size-dependent dominance hierarchies may not have influenced alligator resource selection or space use in our sample. Though apparent habitat suitability and low alligator density did not manifest in an observed dominance hierarchy, we hypothesize that a change in either could increase intraspecific interactions, facilitating a dominance hierarchy. Due to the broad and diverse ecological roles of alligators, understanding the factors that influence their

Scale-dependent habitat selection and size-based dominance in adult male American alligators

Science.gov (United States)

Strickland, Bradley A.; Vilella, Francisco; Belant, Jerrold L.

2016-01-01

Habitat selection is an active behavioral process that may vary across spatial and temporal scales. Animals choose an area of primary utilization (i.e., home range) then make decisions focused on resource needs within patches. Dominance may affect the spatial distribution of conspecifics and concomitant habitat selection. Size-dependent social dominance hierarchies have been documented in captive alligators, but evidence is lacking from wild populations. We studied habitat selection for adult male American alligators (Alligator mississippiensis; n = 17) on the Pearl River in central Mississippi, USA, to test whether habitat selection was scale-dependent and individual resource selectivity was a function of conspecific body size. We used K-select analysis to quantify selection at the home range scale and patches within the home range to determine selection congruency and important habitat variables. In addition, we used linear models to determine if body size was related to selection patterns and strengths. Our results indicated habitat selection of adult male alligators was a scale-dependent process. Alligators demonstrated greater overall selection for habitat variables at the patch level and less at the home range level, suggesting resources may not be limited when selecting a home range for animals in our study area. Further, diurnal habitat selection patterns may depend on thermoregulatory needs. There was no relationship between resource selection or home range size and body size, suggesting size-dependent dominance hierarchies may not have influenced alligator resource selection or space use in our sample. Though apparent habitat suitability and low alligator density did not manifest in an observed dominance hierarchy, we hypothesize that a change in either could increase intraspecific interactions, facilitating a dominance hierarchy. Due to the broad and diverse ecological roles of alligators, understanding the factors that influence their social dominance

Effects of Different Rearing Strategies and Ages on Levels of Natural Antibodies in Saliva of the Philippine Crocodile

NARCIS (Netherlands)

Groffen, J.; Parmentier, H.K.; Ven, van de W.A.C.; Weerd, van M.

2013-01-01

The endemic Philippine crocodile (Crocodylus mindorensis) is a relatively small, critically endangered freshwater crocodile. In a head start program, crocodile hatchlings are caught in the wild, reared in captivity, and released back into the wild after two years. The current study aimed to

Olfactory and solitary chemosensory cells: two different chemosensory systems in the nasal cavity of the American alligator, Alligator mississippiensis

Directory of Open Access Journals (Sweden)

Hansen Anne

2007-08-01

Full Text Available Abstract Background The nasal cavity of all vertebrates houses multiple chemosensors, either innervated by the Ist (olfactory or the Vth (trigeminal cranial nerve. Various types of receptor cells are present, either segregated in different compartments (e.g. in rodents or mingled in one epithelium (e.g. fish. In addition, solitary chemosensory cells have been reported for several species. Alligators which seek their prey both above and under water have only one nasal compartment. Information about their olfactory epithelium is limited. Since alligators seem to detect both volatile and water-soluble odour cues, I tested whether different sensory cell types are present in the olfactory epithelium. Results Electron microscopy and immunocytochemistry were used to examine the sensory epithelium of the nasal cavity of the American alligator. Almost the entire nasal cavity is lined with olfactory (sensory epithelium. Two types of olfactory sensory neurons are present. Both types bear cilia as well as microvilli at their apical endings and express the typical markers for olfactory neurons. The density of these olfactory neurons varies along the nasal cavity. In addition, solitary chemosensory cells innervated by trigeminal nerve fibres, are intermingled with olfactory sensory neurons. Solitary chemosensory cells express components of the PLC-transduction cascade found in solitary chemosensory cells in rodents. Conclusion The nasal cavity of the American alligator contains two different chemosensory systems incorporated in the same sensory epithelium: the olfactory system proper and solitary chemosensory cells. The olfactory system contains two morphological distinct types of ciliated olfactory receptor neurons.

MORPHOLOGICAL VARIATION IN HATCHLING AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) FROM THREE FLORIDA LAKES

Science.gov (United States)

Morphological variation of 508 hatchling alligators from three lakes in north central Florida (Lakes Woodruff, Apopka, and Orange) was analyzed using multivariate statistics. Morphological variation was found among clutches as well as among lakes. Principal components analysis wa...

Effect of aqueous extract of alligator pepper ( Aframomum malegueta )

African Journals Online (AJOL)

... concentration 7days post intervention; and a significant decrease in Cl− concentration 14 days post-intervention. Our findings suggest that intraperitoneally injected aqueous extract of alligator pepper induces reversible changes in serum electrolytes. Key words: Alligator pepper, Electrolytes, Homeostasis, Renal function ...

Biomonitoring Heavy Metal Pollution Using an Aquatic Apex Predator, the American Alligator, and Its Parasites

Science.gov (United States)

Tellez, Marisa; Merchant, Mark

2015-01-01

Monitoring the bioaccumulation of chemical elements within various organismal tissues has become a useful tool to survey current or chronic levels of heavy metal exposure within an environment. In this study, we compared the bioaccumulations of As, Cd, Cu, Fe, Pb, Se, and Zn between the American alligator, Alligator mississippiensis, and its parasites in order to establish their use as bioindicators of heavy metal pollution. Concomitant with these results, we were interested to determine if parasites were more sensitive bioindicators of heavy metals relative to alligators. We found parasites collectively accumulated higher levels of As, Cu, Se, and Zn in comparison to their alligator hosts, whereas Fe, Cd, and Pb concentrations were higher in alligators. Interestingly, Fe levels were significantly greater in intestinal trematodes than their alligator hosts when analyzed independently from other parasitic taxa. Further analyses showed alligator intestinal trematodes concentrated As, Cu, Fe, Se, and Zn at significantly higher levels than intestinal nematodes and parasites from other organs. However, pentastomids also employed the role as a good biomagnifier of As. Interestingly, parasitic abundance decreased as levels of As increased. Stomach and intestinal nematodes were the poorest bioaccumulators of metals, yet stomach nematodes showed their ability to concentrate Pb at orders of magnitude higher in comparison to other parasites. Conclusively, we suggest that parasites, particularly intestinal trematodes, are superior biomagnifiers of As, Cu, Se, and Zn, whereas alligators are likely good biological indicators of Fe, Cd, and Pb levels within the environment. PMID:26555363

Use of alligator hole abundance and occupancy rate as indicators for restoration of a human-altered wetland

Science.gov (United States)

Fujisaki, Ikuko; Mazzotti, Frank J.; Hart, Kristen M.; Rice, Kenneth G.; Ogurcak, Danielle; Rochford, Michael; Jeffery, Brian M.; Brandt, Laura A.; Cherkiss, Michael S.

2012-01-01

Use of indicator species as a measure of ecosystem conditions is an established science application in environmental management. Because of its role in shaping wetland systems, the American alligator (Alligator mississippiensis) is one of the ecological indicators for wetland restoration in south Florida, USA. We conducted landscape-level aerial surveys of alligator holes in two different habitats in a wetland where anthropogenic modification of surface hydrology has altered the natural system. Alligator holes were scarcer in an area where modified hydrology caused draining and frequent dry-downs compared to another area that maintains a functional wetland system. Lower abundance of alligator holes indicates lack of alligator activities, lower overall species diversity, and lack of dry-season aquatic refugia for other organisms. The occupancy rate of alligator holes was lower than the current restoration target for the Everglades, and was variable by size class with large size-class alligators predominantly occupying alligator holes. This may indicate unequal size-class distribution, different habitat selection by size classes, or possibly a lack of recruitment. Our study provides pre-restoration baseline information about one indicator species for the Everglades. Success of the restoration can be assessed via effective synthesis of information derived by collective research efforts on the entire suite of selected ecological indicators.

Normal intestinal flora of wild Nile crocodiles (Crocodylus niloticus in the Okavango Delta, Botswana

Directory of Open Access Journals (Sweden)

C.J. Lovely

2008-05-01

Full Text Available Bacterial and fungal cultures were performed from cloacal swabs collected from 29 wild Nile crocodiles, captured in the Okavango Delta, Botswana. Sixteen species of bacteria and 6 fungal species were cultured. Individual crocodiles yielded 1-4 bacterial species, and 0-2 fungal species. The most commonly isolated bacteria were Microbacterium, Enterococcus faecalis, Aeromonas hydrophila, and Escherichia coli. No salmonellae were cultured. The most commonly occurring fungus was Cladosporium. Several of the bacterial and fungal species isolated have been implicated in cases of septicaemia in crocodilians. Knowledge of the normal intestinal flora will contribute towards the development of a crocodile-specific probiotic for use in farmed crocodiles.

Crocodiles in the Sahara desert: an update of distribution, habitats and population status for conservation planning in Mauritania.

Directory of Open Access Journals (Sweden)

José C Brito

Full Text Available BACKGROUND: Relict populations of Crocodylus niloticus persist in Chad, Egypt and Mauritania. Although crocodiles were widespread throughout the Sahara until the early 20(th century, increased aridity combined with human persecution led to local extinction. Knowledge on distribution, occupied habitats, population size and prey availability is scarce in most populations. This study evaluates the status of Saharan crocodiles and provides new data for Mauritania to assist conservation planning. METHODOLOGY/PRINCIPAL FINDINGS: A series of surveys in Mauritania detected crocodile presence in 78 localities dispersed across 10 river basins and most tended to be isolated within river basins. Permanent gueltas and seasonal tâmoûrts were the most common occupied habitats. Crocodile encounters ranged from one to more than 20 individuals, but in most localities less than five crocodiles were observed. Larger numbers were observed after the rainy season and during night sampling. Crocodiles were found dead in between water points along dry river-beds suggesting the occurrence of dispersal. CONCLUSION/SIGNIFICANCE: Research priorities in Chad and Egypt should focus on quantifying population size and pressures exerted on habitats. The present study increased in by 35% the number of known crocodile localities in Mauritania. Gueltas are crucial for the persistence of mountain populations. Oscillations in water availability throughout the year and the small dimensions of gueltas affect biological traits, including activity and body size. Studies are needed to understand adaptation traits of desert populations. Molecular analyses are needed to quantify genetic variability, population sub-structuring and effective population size, and detect the occurrence of gene flow. Monitoring is needed to detect demographical and genetical trends in completely isolated populations. Crocodiles are apparently vulnerable during dispersal events. Awareness campaigns focusing on

Biophysics of directional hearing in the American alligator (Alligator mississippiensis)

DEFF Research Database (Denmark)

Bierman, Hilary S; Thornton, Jennifer L; Jones, Heath G

2014-01-01

Physiological and anatomical studies have suggested that alligators have unique adaptations for spatial hearing. Sound localization cues are primarily generated by the filtering of sound waves by the head. Different vertebrate lineages have evolved external and/or internal anatomical adaptations ...... in the extinct dinosaurs....

Metals and organochlorine pesticides in caudal scutes of crocodiles from Belize and Costa Rica

Energy Technology Data Exchange (ETDEWEB)

Rainwater, Thomas R. [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409 (United States)]. E-mail: thomas.rainwater@tiehh.ttu.edu; Wu, Ted H. [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409 (United States); Finger, Adam G. [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409 (United States); Canas, Jaclyn E. [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409 (United States); Yu Lu [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409 (United States); Reynolds, Kevin D. [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409 (United States); Coimbatore, Gopal [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409 (United States); Barr, Brady [National Geographic Channel, 1145 17th St. NW Washington, DC 20036 (United States); Platt, Steven G. [Department of Biology, Box C-64, Sul Ross State University, Alpine, TX 79832 (United States); Cobb, George P. [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409 (United States); Anderson, Todd A. [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409 (United States); McMurry, Scott T. [Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409 (United States)

2007-02-01

Despite high animal diversity in the Neotropics and the largely unregulated use and disposal of pesticides and industrial chemicals in Central America, few data exist regarding accumulation of environmental contaminants in Central American wildlife. In this study we examined accumulation of metals and organochlorine (OC) pesticides in caudal scutes of crocodiles from Belize and Costa Rica. Scutes from Morelet's crocodiles (Crocodylus moreletii) from two sites in northern Belize were analyzed for metals, and scutes from American crocodiles (C. acutus) from one site in Costa Rica were analyzed for metals and OC pesticides. All scutes (n = 25; one scute from each of 25 individuals) contained multiple contaminants. Mercury was the predominant metal detected, occurring in all scutes examined from both species. Other metals detected include cadmium, copper, lead, and zinc. American crocodile scutes from Costa Rica contained multiple OC pesticides, including endrin, methoxychlor, p,p'-DDE, and p,p'-DDT, all of which occurred in 100% of scutes analyzed (n = 6). Mean metal and OC concentrations varied in relation to those previously reported in crocodilian scutes from other localities in North, Central, and South America. OC concentrations in American crocodile scutes were generally higher than those previously reported for other Costa Rican wildlife. Currently, caudal scutes may serve as general, non-lethal indicators of contaminant accumulation in crocodilians and their areas of occurrence. However, a better understanding of the relationships between pollutant concentrations in scutes, internal tissues, and environmental matrices at sample collection sites are needed to improve the utility of scutes in future ecotoxicological investigations.

Metals and organochlorine pesticides in caudal scutes of crocodiles from Belize and Costa Rica

International Nuclear Information System (INIS)

Rainwater, Thomas R.; Wu, Ted H.; Finger, Adam G.; Canas, Jaclyn E.; Yu Lu; Reynolds, Kevin D.; Coimbatore, Gopal; Barr, Brady; Platt, Steven G.; Cobb, George P.; Anderson, Todd A.; McMurry, Scott T.

2007-01-01

Despite high animal diversity in the Neotropics and the largely unregulated use and disposal of pesticides and industrial chemicals in Central America, few data exist regarding accumulation of environmental contaminants in Central American wildlife. In this study we examined accumulation of metals and organochlorine (OC) pesticides in caudal scutes of crocodiles from Belize and Costa Rica. Scutes from Morelet's crocodiles (Crocodylus moreletii) from two sites in northern Belize were analyzed for metals, and scutes from American crocodiles (C. acutus) from one site in Costa Rica were analyzed for metals and OC pesticides. All scutes (n = 25; one scute from each of 25 individuals) contained multiple contaminants. Mercury was the predominant metal detected, occurring in all scutes examined from both species. Other metals detected include cadmium, copper, lead, and zinc. American crocodile scutes from Costa Rica contained multiple OC pesticides, including endrin, methoxychlor, p,p'-DDE, and p,p'-DDT, all of which occurred in 100% of scutes analyzed (n = 6). Mean metal and OC concentrations varied in relation to those previously reported in crocodilian scutes from other localities in North, Central, and South America. OC concentrations in American crocodile scutes were generally higher than those previously reported for other Costa Rican wildlife. Currently, caudal scutes may serve as general, non-lethal indicators of contaminant accumulation in crocodilians and their areas of occurrence. However, a better understanding of the relationships between pollutant concentrations in scutes, internal tissues, and environmental matrices at sample collection sites are needed to improve the utility of scutes in future ecotoxicological investigations

Abundance, distribution and population trends of Nile crocodile (Crocodylus niloticus) in Gonarezhou National Park, Zimbabwe

NARCIS (Netherlands)

Zisadza-Gandiwa, P.; Gandiwa, E.; Jakarasi, J.; Westhuizen, van der H.; Muvengwi, J.

2013-01-01

The Nile crocodile (Crocodylus niloticus) is an iconic or keystone species in many aquatic ecosystems. In order to understand the abundance, distribution, and population trends of Nile crocodiles in Gonarezhou National Park (GNP), southeastern Zimbabwe, we carried out 4 annual aerial surveys, using

A check-list of the pentastomid parasites of crocodilians and freshwater chelonians

Directory of Open Access Journals (Sweden)

K. Junker

2006-09-01

Full Text Available Based on published records and own data a summary is given of the geographical distribution of the currently known species of pentastomid parasites infecting crocodiles and alligators, as well as freshwater chelonians. A brief generic diagnosis is provided for each genus. Fourteen out of the currently 23 living crocodilian species have been recorded as being host to one or more pentastomes. Out of the 32 pentastome species six are considered species inquirendae. Presently, six genera of crocodilian pentastomes, Agema, Alofia, Leiperia, Sebekia, Selfia and Subtriquetra are recognized. African crocodiles harbour eight pentastome species, six of which have been recorded from the Nile crocodile, Crocodylus niloticus. Three species belong to the genus Sebekia, Alofia being represented by two and Leiperia by only one species. Two species, Alofia parva and Agema silvaepalustris, occur in the dwarf crocodile, Osteolaemus tetraspis, and the slender-snouted crocodile, Crocodylus cataphractus, exclusively, but a single Sebekia species is shared with the Nile crocodile. The genus Agema is endemic to the African region. Infective stages of the pentastome Sub triquetra rileyi, thought to utilize Nile crocodiles as final hosts, have been recovered only from fishes. The largest number of pentastome species is found in the Australasian region. Of these, the Indo-Pacific croc odile, Crocodylus porosus, harbours seven, representing the genera Alofia, Sebekia, Lei peria and Selfia. Selfia is exclusive to the latter host. The genus Subtriquetra has been reported from "Indian crocodiles", a term possibly referring to either Crocodylus palustris, Crocodylus porosus or Gavialis gangeticus. Ten species of pentastomes parasitizing the crocodilian genera Alligator, Caiman, Crocodylus and Melanosuchus have been recorded from the Neotropical region including the southern states of the North American continent. The two most wide-spread pentastome genera, Alofia and Sebekia

Science: What Reptiles Are and Aren't

Science.gov (United States)

Axelrod, Gerry S.

1978-01-01

Many children have an enormous fascination for reptiles of all kinds--snakes, turtles, tortoises, crocodiles, alligators and lizards. Whatever the reason for their interest, you can channel the enthusiasm of reptile fans and build the interest of curious students with a few simple activities, e.g., getting acquainted with reptile characteristics…

Dead or Alive? Factors Affecting the Survival of Victims during Attacks by Saltwater Crocodiles (Crocodylus porosus in Australia.

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Yusuke Fukuda

Full Text Available Conflicts between humans and crocodilians are a widespread conservation challenge and the number of crocodile attacks is increasing worldwide. We identified the factors that most effectively decide whether a victim is injured or killed in a crocodile attack by fitting generalized linear models to a 42-year dataset of 87 attacks (27 fatal and 60 non-fatal by saltwater crocodiles (Crocodylus porosus in Australia. The models showed that the most influential factors were the difference in body mass between crocodile and victim, and the position of victim in relation to the water at the time of an attack. In-water position (for diving, swimming, and wading had a higher risk than on-water (boating or on-land (fishing, and hunting near the water's edge positions. In the in-water position a 75 kg person would have a relatively high probability of survival (0.81 if attacked by a 300 cm crocodile, but the probability becomes much lower (0.17 with a 400 cm crocodile. If attacked by a crocodile larger than 450 cm, the survival probability would be extremely low (<0.05 regardless of the victim's size. These results indicate that the main cause of death during a crocodile attack is drowning and larger crocodiles can drag a victim more easily into deeper water. A higher risk associated with a larger crocodile in relation to victim's size is highlighted by children's vulnerability to fatal attacks. Since the first recently recorded fatal attack involving a child in 2006, six out of nine fatal attacks (66.7% involved children, and the average body size of crocodiles responsible for these fatal attacks was considerably smaller (384 cm, 223 kg than that of crocodiles that killed adults (450 cm, 324 kg during the same period (2006-2014. These results suggest that culling programs targeting larger crocodiles may not be an effective management option to improve safety for children.

Maximal aerobic and anaerobic power generation in large crocodiles versus mammals: implications for dinosaur gigantothermy.

Science.gov (United States)

Seymour, Roger S

2013-01-01

Inertial homeothermy, the maintenance of a relatively constant body temperature that occurs simply because of large size, is often applied to large dinosaurs. Moreover, biophysical modelling and actual measurements show that large crocodiles can behaviourally achieve body temperatures above 30°C. Therefore it is possible that some dinosaurs could achieve high and stable body temperatures without the high energy cost of typical endotherms. However it is not known whether an ectothermic dinosaur could produce the equivalent amount of muscular power as an endothermic one. To address this question, this study analyses maximal power output from measured aerobic and anaerobic metabolism in burst exercising estuarine crocodiles, Crocodylusporosus, weighing up to 200 kg. These results are compared with similar data from endothermic mammals. A 1 kg crocodile at 30°C produces about 16 watts from aerobic and anaerobic energy sources during the first 10% of exhaustive activity, which is 57% of that expected for a similarly sized mammal. A 200 kg crocodile produces about 400 watts, or only 14% of that for a mammal. Phosphocreatine is a minor energy source, used only in the first seconds of exercise and of similar concentrations in reptiles and mammals. Ectothermic crocodiles lack not only the absolute power for exercise, but also the endurance, that are evident in endothermic mammals. Despite the ability to achieve high and fairly constant body temperatures, therefore, large, ectothermic, crocodile-like dinosaurs would have been competitively inferior to endothermic, mammal-like dinosaurs with high aerobic power. Endothermy in dinosaurs is likely to explain their dominance over mammals in terrestrial ecosystems throughout the Mesozoic.

Maximal aerobic and anaerobic power generation in large crocodiles versus mammals: implications for dinosaur gigantothermy.

Directory of Open Access Journals (Sweden)

Roger S Seymour

Full Text Available Inertial homeothermy, the maintenance of a relatively constant body temperature that occurs simply because of large size, is often applied to large dinosaurs. Moreover, biophysical modelling and actual measurements show that large crocodiles can behaviourally achieve body temperatures above 30°C. Therefore it is possible that some dinosaurs could achieve high and stable body temperatures without the high energy cost of typical endotherms. However it is not known whether an ectothermic dinosaur could produce the equivalent amount of muscular power as an endothermic one. To address this question, this study analyses maximal power output from measured aerobic and anaerobic metabolism in burst exercising estuarine crocodiles, Crocodylusporosus, weighing up to 200 kg. These results are compared with similar data from endothermic mammals. A 1 kg crocodile at 30°C produces about 16 watts from aerobic and anaerobic energy sources during the first 10% of exhaustive activity, which is 57% of that expected for a similarly sized mammal. A 200 kg crocodile produces about 400 watts, or only 14% of that for a mammal. Phosphocreatine is a minor energy source, used only in the first seconds of exercise and of similar concentrations in reptiles and mammals. Ectothermic crocodiles lack not only the absolute power for exercise, but also the endurance, that are evident in endothermic mammals. Despite the ability to achieve high and fairly constant body temperatures, therefore, large, ectothermic, crocodile-like dinosaurs would have been competitively inferior to endothermic, mammal-like dinosaurs with high aerobic power. Endothermy in dinosaurs is likely to explain their dominance over mammals in terrestrial ecosystems throughout the Mesozoic.

Dead or Alive? Factors Affecting the Survival of Victims during Attacks by Saltwater Crocodiles (Crocodylus porosus) in Australia.

Science.gov (United States)

Fukuda, Yusuke; Manolis, Charlie; Saalfeld, Keith; Zuur, Alain

2015-01-01

Conflicts between humans and crocodilians are a widespread conservation challenge and the number of crocodile attacks is increasing worldwide. We identified the factors that most effectively decide whether a victim is injured or killed in a crocodile attack by fitting generalized linear models to a 42-year dataset of 87 attacks (27 fatal and 60 non-fatal) by saltwater crocodiles (Crocodylus porosus) in Australia. The models showed that the most influential factors were the difference in body mass between crocodile and victim, and the position of victim in relation to the water at the time of an attack. In-water position (for diving, swimming, and wading) had a higher risk than on-water (boating) or on-land (fishing, and hunting near the water's edge) positions. In the in-water position a 75 kg person would have a relatively high probability of survival (0.81) if attacked by a 300 cm crocodile, but the probability becomes much lower (0.17) with a 400 cm crocodile. If attacked by a crocodile larger than 450 cm, the survival probability would be extremely low (drag a victim more easily into deeper water. A higher risk associated with a larger crocodile in relation to victim's size is highlighted by children's vulnerability to fatal attacks. Since the first recently recorded fatal attack involving a child in 2006, six out of nine fatal attacks (66.7%) involved children, and the average body size of crocodiles responsible for these fatal attacks was considerably smaller (384 cm, 223 kg) than that of crocodiles that killed adults (450 cm, 324 kg) during the same period (2006-2014). These results suggest that culling programs targeting larger crocodiles may not be an effective management option to improve safety for children.

Hexavalent Chromium Is Cytotoxic and Genotoxic to American Alligator Cells

OpenAIRE

Wise, Sandra S.; Wise, Catherine; Xie, Hong; Guillette, Louis J.; Zhu, Cairong; Wise, John Pierce; Wise, John Pierce

2015-01-01

Metals are a common pollutant in the aquatic ecosystem. With global climate change, these levels are anticipated to rise as lower pH levels allow sediment bound metals to be released. The American alligator (Alligator mississippiensis) is an apex predator in the aquatic ecosystem and is considered a keystone species; as such it serves as a suitable monitor for localized pollution. One metal of increasing concern is hexavalent chromium (Cr(VI)). It is present in the aquatic environment and is ...

A preliminary disease survey in the wild Nile crocodile (Crocodylus niloticus population in the Okavango Delta, Botswana

Directory of Open Access Journals (Sweden)

A. J. Leslie

2011-04-01

Full Text Available The objective of this study was to conduct a preliminary survey of diseases that might be present in the wild Nile crocodile population in the Okavango Delta, Botswana. Blood samples were collected from crocodiles ranging in size from 34.0cmto 463.0cmtotal length. Samples were examined for blood parasites and underwent a haematological analysis. Before release the crocodiles were examined for various clinical abnormalities. Of the 144 crocodiles examined, none were visibly sick or displayed any signs of disease. No antibodies to Mycoplasma crocodyli were detected. Hepatozoon pettiti was present in 55.3 % of blood smears examined, but there was no significant difference in any of the haematological values between the infected and uninfected crocodiles, and a high prevalence of Hepatozoon infection is not uncommon in other species. Only 7.6 % of the examined crocodiles were infested with leeches. Further research is required for several of the crocodilian diseases, in particular to elucidate the role of wild crocodilians as reservoirs of infection.

Mitochondrial 16S ribosomal RNA gene for forensic identification of crocodile species.

Science.gov (United States)

Naga Jogayya, K; Meganathan, P R; Dubey, Bhawna; Haque, I

2013-05-01

All crocodilians are under various threats due to over exploitation and these species have been listed in Appendix I or II of CITES. Lack of molecular techniques for the forensic identification of confiscated samples makes it difficult to enforce the law. Therefore, we herein present a molecular method developed on the basis on 16S rRNA gene of mitochondrial DNA for identification of crocodile species. We have developed a set of 16S rRNA primers for PCR based identification of crocodilian species. These novel primers amplify partial 16S rRNA sequences of six crocodile species which can be later combined to obtain a larger region (1290 bp) of 16S rRNA gene. This 16S rRNA gene could be used as an effective tool for forensic authentication of crocodiles. The described primers hold great promise in forensic identification of crocodile species, which can aid in the effective enforcement of law and conservation of these species. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Characterization of Serum Phospholipase A2 Activity in Three Diverse Species of West African Crocodiles

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Mark Merchant

2011-01-01

Full Text Available Secretory phospholipase A2, an enzyme that exhibits substantial immunological activity, was measured in the serum of three species of diverse West African crocodiles. Incubation of different volumes of crocodile serum with bacteria labeled with a fluorescent fatty acid in the sn-2 position of membrane lipids resulted in a volume-dependent liberation of fluorescent probe. Serum from the Nile crocodile (Crocodylus niloticus exhibited slightly higher activity than that of the slender-snouted crocodile (Mecistops cataphractus and the African dwarf crocodile (Osteolaemus tetraspis. Product formation was inhibited by BPB, a specific PLA2 inhibitor, confirming that the activity was a direct result of the presence of serum PLA2. Kinetic analysis showed that C. niloticus serum produced product more rapidly than M. cataphractus or O. tetraspis. Serum from all three species exhibited temperature-dependent PLA2 activities but with slightly different thermal profiles. All three crocodilian species showed high levels of activity against eight different species of bacteria.

Estimating trends in alligator populations from nightlight survey data

Science.gov (United States)

Fujisaki, Ikuko; Mazzotti, Frank J.; Dorazio, Robert M.; Rice, Kenneth G.; Cherkiss, Michael; Jeffery, Brian

2011-01-01

Nightlight surveys are commonly used to evaluate status and trends of crocodilian populations, but imperfect detection caused by survey- and location-specific factors makes it difficult to draw population inferences accurately from uncorrected data. We used a two-stage hierarchical model comprising population abundance and detection probability to examine recent abundance trends of American alligators (Alligator mississippiensis) in subareas of Everglades wetlands in Florida using nightlight survey data. During 2001–2008, there were declining trends in abundance of small and/or medium sized animals in a majority of subareas, whereas abundance of large sized animals had either demonstrated an increased or unclear trend. For small and large sized class animals, estimated detection probability declined as water depth increased. Detection probability of small animals was much lower than for larger size classes. The declining trend of smaller alligators may reflect a natural population response to the fluctuating environment of Everglades wetlands under modified hydrology. It may have negative implications for the future of alligator populations in this region, particularly if habitat conditions do not favor recruitment of offspring in the near term. Our study provides a foundation to improve inferences made from nightlight surveys of other crocodilian populations.

Meningkatkan Hasil Belajar Listrik Dinamik menggunakan Strategi Pembelajaran Team Assisted Individualization melalui Simulasi Crocodile Physics

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Ahmad Gumrowi

2016-04-01

through physics crocodile simulation. This study was conducted in three cycles. The results of analysis show that cooperative learning strategies type Team Assisted Individualization through crocodile physics simulations can improve learning outcomes on dynamic electricity. The average of students’ learning outcomes increased as follows: the first cycle is 61.23, and 68.13 in the second cycle, an increase of 11.27%, and the third cycle result is 72.63, or an increase of 6.6%. Penelitian ini bertujuan untuk meningkatkan hasil belajar listrik dinamik siswa MAN 1 Bandar Lampung dengan menggunakan model pembelajaran kooperatif tipe Team Assisted Individualization (TAI. melalui simulasi Crocodile physics. Objek penelitian ini adalah hasil belajar siswa pada pokok bahasan listrik dinamik dengan model pembelajaran kooperatif Tipe TAI (team assisted individualization melalui simulasi Crocodile physics. Penelitian ini dilaksanakan selama tiga siklus, dari hasil analisis diperoleh bahwa strategi pembelajaran kooperatif tipe Team Assisted Individualization melalui simulasi crocodile physics dapat meningkatkan hasil belajar listrik dinamik. Rata-rata hasil belajar siswa meningkat pada siklus I dari 61,23 menjadi 68,13 pada siklus II atau meningkat 11,27%, pada siklus III 72,63 atau meningkat 6,6% Kata Kunci: cooperatif tipe TAI, listrik dinamik, simulasi crocodile physics

Identification of the Nile crocodile Crocodylus niloticus by the use of natural tail marks

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D.G.J. Swanepoel

1996-08-01

Full Text Available The tail marks of 190 Nile crocodiles Crocodylus niloticus were documented and processed into codes. The size of the crocodiles varied from 45 cm to 4.6 m in total length. Wherever possible, both sides of the tails were observed and the marks documented. In all remaining instances only one side could be identified. A total of 267 sides were identified. The natural marks on nine segments of a specific portion of the tail was recorded and compared as codes. For this comparison two methods were employed. Differences of 95.1 and 100 was found with the respective methods. This is an indication that every crocodile has a unique pattern of natural marks on its tail. The marks can therefore be used to allocate a code to an individual crocodile that partially eliminates the necessity of artificial marking methods.

Identification of the Nile crocodile Crocodylus niloticus by the use of natural tail marks

Directory of Open Access Journals (Sweden)

D.G.J. Swanepoel

1996-01-01

Full Text Available The tail marks of 190 Nile crocodiles Crocodylus niloticus were documented and processed into codes. The size of the crocodiles varied from 45 cm to 4.6 m in total length. Wherever possible, both sides of the tails were observed and the marks documented. In all remaining instances only one side could be identified. A total of 267 sides were identified. The natural marks on nine segments of a specific portion of the tail was recorded and compared as codes. For this comparison two methods were employed. Differences of 95.1 and 100 was found with the respective methods. This is an indication that every crocodile has a unique pattern of natural marks on its tail. The marks can therefore be used to allocate a code to an individual crocodile that partially eliminates the necessity of artificial marking methods.

HNK-1 immunoreactivity during early morphogenesis of the head region in a nonmodel vertebrate, crocodile embryo

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Kundrát, Martin

2008-11-01

The present study examines HNK-1 immunoidentification of a population of the neural crest (NC) during early head morphogenesis in the nonmodel vertebrate, the crocodile ( Crocodylus niloticus) embryos. Although HNK-1 is not an exclusive NC marker among vertebrates, temporospatial immunoreactive patterns found in the crocodile are almost consistent with NC patterns derived from gene expression studies known in birds (the closest living relatives of crocodiles) and mammals. In contrast to birds, the HNK-1 epitope is immunoreactive in NC cells at the neural fold level in crocodile embryos and therefore provides sufficient base to assess early migratory events of the cephalic NC. I found that crocodile NC forms three classic migratory pathways in the head: mandibular, hyoid, and branchial. Further, I demonstrate that, besides this classic phenotype, there is also a forebrain-derived migratory population, which consolidates into a premandibular stream in the crocodile. In contrast to the closely related chick model, crocodilian premandibular and mandibular NC cells arise from the open neural tube suggesting that species-specific heterochronic behavior of NC may be involved in the formation of different vertebrate facial phenotypes.

The effects of hurricane Rita and subsequent drought on alligators in southwest Louisiana.

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Lance, Valentine A; Elsey, Ruth M; Butterstein, George; Trosclair, Phillip L; Merchant, Mark

2010-02-01

Hurricane Rita struck the coast of southwest Louisiana in September 2005. The storm generated an enormous tidal surge of approximately four meters in height that inundated many thousands of acres of the coastal marsh with full strength seawater. The initial surge resulted in the deaths of a number of alligators and severely stressed those who survived. In addition, a prolonged drought (the lowest rainfall in 111 years of recorded weather data) following the hurricane resulted in highly saline conditions that persisted in the marsh for several months. We had the opportunity to collect 11 blood samples from alligators located on Holly Beach less than a month after the hurricane, but were unable to collect samples from alligators on Rockefeller Wildlife Refuge until February 2006. Conditions at Rockefeller Refuge did not permit systematic sampling, but a total of 201 samples were collected on the refuge up through August 2006. The blood samples were analyzed for sodium, potassium, chloride, osmolality, and corticosterone. Blood samples from alligators sampled on Holly Beach in October 2005, showed a marked elevation in plasma osmolality, sodium, chloride, potassium, corticosterone, and an elevated heterophil/lymphocyte ratio. Blood samples from alligators on Rockefeller Refuge showed increasing levels of corticosterone as the drought persisted and elevated osmolality and electrolytes. After substantial rainfall in July and August, these indices of osmotic stress returned to within normal limits. (c) 2009 Wiley-Liss, Inc.

EFFECT OF ALLIGATOR PEPPER (ZINGIBERACEAE ...

African Journals Online (AJOL)

Daniel Owu

proven fertility from a pilot study were randomly paired in fifteen cages in a well ventillated room. After three days of ... Key words : Effect, Alligator pepper, Herbal remedy, Nutrition, Pregnancy. Introduction ... ad libitum. Experimental drug.

Evaluating the effect of sample type on American alligator (Alligator mississippiensis) analyte values in a point-of-care blood analyser.

Science.gov (United States)

Hamilton, Matthew T; Finger, John W; Winzeler, Megan E; Tuberville, Tracey D

2016-01-01

The assessment of wildlife health has been enhanced by the ability of point-of-care (POC) blood analysers to provide biochemical analyses of non-domesticated animals in the field. However, environmental limitations (e.g. temperature, atmospheric humidity and rain) and lack of reference values may inhibit researchers from using such a device with certain wildlife species. Evaluating the use of alternative sample types, such as plasma, in a POC device may afford researchers the opportunity to delay sample analysis and the ability to use banked samples. In this study, we examined fresh whole blood, fresh plasma and frozen plasma (sample type) pH, partial pressure of carbon dioxide (PCO2), bicarbonate (HCO3 (-)), total carbon dioxide (TCO2), base excess (BE), partial pressure of oxygen (PO2), oxygen saturation (sO2) and lactate concentrations in 23 juvenile American alligators (Alligator mississippiensis) using an i-STAT CG4+ cartridge. Our results indicate that sample type had no effect on lactate concentration values (F 2,65 = 0.37, P = 0.963), suggesting that the i-STAT analyser can be used reliably to quantify lactate concentrations in fresh and frozen plasma samples. In contrast, the other seven blood parameters measured by the CG4+ cartridge were significantly affected by sample type. Lastly, we were able to collect blood samples from all alligators within 2 min of capture to establish preliminary reference ranges for juvenile alligators based on values obtained using fresh whole blood.

Distinguishing butchery cut marks from crocodile bite marks through machine learning methods.

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Domínguez-Rodrigo, Manuel; Baquedano, Enrique

2018-04-10

All models of evolution of human behaviour depend on the correct identification and interpretation of bone surface modifications (BSM) on archaeofaunal assemblages. Crucial evolutionary features, such as the origin of stone tool use, meat-eating, food-sharing, cooperation and sociality can only be addressed through confident identification and interpretation of BSM, and more specifically, cut marks. Recently, it has been argued that linear marks with the same properties as cut marks can be created by crocodiles, thereby questioning whether secure cut mark identifications can be made in the Early Pleistocene fossil record. Powerful classification methods based on multivariate statistics and machine learning (ML) algorithms have previously successfully discriminated cut marks from most other potentially confounding BSM. However, crocodile-made marks were marginal to or played no role in these comparative analyses. Here, for the first time, we apply state-of-the-art ML methods on crocodile linear BSM and experimental butchery cut marks, showing that the combination of multivariate taphonomy and ML methods provides accurate identification of BSM, including cut and crocodile bite marks. This enables empirically-supported hominin behavioural modelling, provided that these methods are applied to fossil assemblages.

Distribution patterns and predilection muscles of Trichinella zimbabwensis larvae in experimentally infected Nile crocodiles (Crocodylus niloticus Laurenti

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Louis J. La Grange

2014-02-01

Full Text Available No controlled studies have been conducted to determine the predilection muscles of Trichinella zimbabwensis larvae in Nile crocodiles (Crocodylus niloticus or the influence of infection intensity on the distribution of the larvae in crocodiles. The distribution of larvae in muscles of naturally infected Nile crocodiles and experimentally infected caimans (Caiman crocodilus and varans (Varanus exanthematicus have been reported in literature. To determine the distribution patterns of T. zimbabwensis larvae and predilection muscles, 15 crocodiles were randomly divided into three cohorts of five animals each, representing high infection (642 larvae/kg of bodyweight average, medium infection (414 larvae/kg of bodyweight average and low infection (134 larvae/kg of bodyweight average cohorts. In the high infection cohort, high percentages of larvae were observed in the triceps muscles (26% and hind limb muscles (13%. In the medium infection cohort, high percentages of larvae were found in the triceps muscles (50%, sternomastoid (18% and hind limb muscles (13%. In the low infection cohort, larvae were mainly found in the intercostal muscles (36%, longissimus complex (27%, forelimb muscles (20% and hind limb muscles (10%. Predilection muscles in the high and medium infection cohorts were similar to those reported in naturally infected crocodiles despite changes in infection intensity. The high infection cohort had significantly higher numbers of larvae in the sternomastoid, triceps, intercostal, longissimus complex, external tibial flexor, longissimus caudalis and caudal femoral muscles (p < 0.05 compared with the medium infection cohort. In comparison with the low infection cohort, the high infection cohort harboured significantly higher numbers of larvae in all muscles (p < 0.05 except for the tongue. The high infection cohort harboured significantly higher numbers of larvae (p < 0.05 in the sternomastoid, triceps, intercostal, longissimus complex

Alligators and Crocodiles Have High Paracellular Absorption of Nutrients, But Differ in Digestive Morphology and Physiology.

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Tracy, Christopher R; McWhorter, Todd J; Gienger, C M; Starck, J Matthias; Medley, Peter; Manolis, S Charlie; Webb, Grahame J W; Christian, Keith A

2015-12-01

Much of what is known about crocodilian nutrition and growth has come from animals propagated in captivity, but captive animals from the families Crocodilidae and Alligatoridae respond differently to similar diets. Since there are few comparative studies of crocodilian digestive physiology to help explain these differences, we investigated young Alligator mississippiensis and Crocodylus porosus in terms of (1) gross and microscopic morphology of the intestine, (2) activity of the membrane-bound digestive enzymes aminopeptidase-N, maltase, and sucrase, and (3) nutrient absorption by carrier-mediated and paracellular pathways. We also measured gut morphology of animals over a larger range of body sizes. The two species showed different allometry of length and mass of the gut, with A. mississippiensis having a steeper increase in intestinal mass with body size, and C. porosus having a steeper increase in intestinal length with body size. Both species showed similar patterns of magnification of the intestinal surface area, with decreasing magnification from the proximal to distal ends of the intestine. Although A. mississippiensis had significantly greater surface-area magnification overall, a compensating significant difference in gut length between species meant that total surface area of the intestine was not significantly different from that of C. porosus. The species differed in enzyme activities, with A. mississippiensis having significantly greater ability to digest carbohydrates relative to protein than did C. porosus. These differences in enzyme activity may help explain the differences in performance between the crocodilian families when on artificial diets. Both A. mississippiensis and C. porosus showed high absorption of 3-O methyl d-glucose (absorbed via both carrier-mediated and paracellular transport), as expected. Both species also showed surprisingly high levels of l-glucose-uptake (absorbed paracellularly), with fractional absorptions as high as those

Animal-Borne Imaging Reveals Novel Insights into the Foraging Behaviors and Diel Activity of a Large-Bodied Apex Predator, the American Alligator (Alligator mississippiensis)

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Nifong, James C.; Nifong, Rachel L.; Silliman, Brian R.; Lowers, Russell H.; Guillette, Louis J.; Ferguson, Jake M.; Welsh, Matthew; Abernathy, Kyler; Marshall, Greg

2014-01-01

Large-bodied, top- and apex predators (e.g., crocodilians, sharks, wolves, killer whales) can exert strong top-down effects within ecological communities through their interactions with prey. Due to inherent difficulties while studying the behavior of these often dangerous predatory species, relatively little is known regarding their feeding behaviors and activity patterns, information that is essential to understanding their role in regulating food web dynamics and ecological processes. Here we use animal-borne imaging systems (Crittercam) to study the foraging behavior and activity patterns of a cryptic, large-bodied predator, the American alligator (Alligator mississippiensis) in two estuaries of coastal Florida, USA. Using retrieved video data we examine the variation in foraging behaviors and activity patterns due to abiotic factors. We found the frequency of prey-attacks (mean = 0.49 prey attacks/hour) as well as the probability of prey-capture success (mean = 0.52 per attack) were significantly affected by time of day. Alligators attempted to capture prey most frequently during the night. Probability of prey-capture success per attack was highest during morning hours and sequentially lower during day, night, and sunset, respectively. Position in the water column also significantly affected prey-capture success, as individuals’ experienced two-fold greater success when attacking prey while submerged. These estimates are the first for wild adult American alligators and one of the few examples for any crocodilian species worldwide. More broadly, these results reveal that our understandings of crocodilian foraging behaviors are biased due to previous studies containing limited observations of cryptic and nocturnal foraging interactions. Our results can be used to inform greater understanding regarding the top-down effects of American alligators in estuarine food webs. Additionally, our results highlight the importance and power of using animal

Concentrations of trace elements in American alligators (Alligator mississippiensis) from Florida, USA.

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Horai, Sawako; Itai, Takaaki; Noguchi, Takako; Yasuda, Yusuke; Adachi, Haruki; Hyobu, Yuika; Riyadi, Adi S; Boggs, Ashley S P; Lowers, Russell; Guillette, Louis J; Tanabe, Shinsuke

2014-08-01

Concentrations of 28 trace elements (Li, Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Tl, Hg, Pb, and Bi) in the livers of juvenile and adult American alligators inhabiting two central Florida lakes, Lake Apopka (LA), and Lake Woodruff National Wildlife Refuge (LW) and one lagoon population located in Merritt Island National Wildlife Refuge (MINWR; NASA), were determined. In juveniles from MINWR, concentrations of nine elements (Li, Fe, Ni, Sr, In, Sb, Hg, Pb and Bi) were significantly higher, whereas six elements (V, Fe, As, Sr, Hg and Bi) were elevated in adults (pLA, LW and MINWR were 1770 μg g(-1) DW, 3690 μg g(-1) DW and 5250 μg g(-1) DW, respectively. More than half of the adult specimens from LW and MINWR exhibited elevated hepatic Fe concentrations that exceed the threshold value for toxic effects in donkey, red deer and human. These results prompted us to express our concern on possible exposure and health effects in American alligators by some trace elements derived from NASA activities. Copyright © 2014 Elsevier Ltd. All rights reserved.

American alligator digestion rate of blue crabs and its implications for stomach contents analysis

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Nifong, James C.; Rosenblatt, Adam E.; Johnson, Nathan A.; Barichivich, William; Silliman, Brian; Heithaus, Michael R.

2012-01-01

Stomach contents analysis (SCA) provides a snap-shot observation of a consumer's diet. Interpretation of SCA data can be complicated by many factors, including variation in gastric residence times and digestion rates among prey taxa. Although some SCA methods are reported to efficiently remove all stomach contents, the effectiveness of these techniques has rarely been tested for large irregular shaped prey with hard exoskeletons. We used a controlled feeding trial to estimate gastric residency time and decomposition rate of a large crustacean prey item, the Blue Crab (Callinectes sapidus), which is consumed by American Alligators (Alligator mississippiensis), an abundant apex predator in coastal habitats of the southeastern United States. The decomposition rate of C. sapidus in the stomachs of A. mississippiensis followed a predictable pattern, and some crab pieces remained in stomachs for at least 14 days. We also found that certain portions of C. sapidus were prone to becoming caught within the stomach or esophagus, meaning not all crab parts are consistently recovered using gastric lavage techniques. However, because the state of decomposition of crabs was predictable, it is possible to estimate time since consumption for crabs recovered from wild alligators. This information, coupled with a detailed understanding of crab distributions and alligator movement tactics could help elucidate patterns of cross-ecosystem foraging by the American Alligator in coastal habitats

Plasma vitellogenin in Morelet's crocodiles from contaminated habitats in northern Belize

International Nuclear Information System (INIS)

Rainwater, Thomas R.; Selcer, Kyle W.; Nespoli, Lisa M.; Finger, Adam G.; Ray, David A.; Platt, Steven G.; Smith, Philip N.; Densmore, Llewellyn D.; Anderson, Todd A.; McMurry, Scott T.

2008-01-01

Vitellogenin induction has been widely used as a biomarker of endocrine disruption in wildlife, but few studies have investigated its use in wild reptiles living in contaminated habitats. This study examined vitellogenin induction in Morelet's crocodiles (Crocodylus moreletii) from wetlands in northern Belize contaminated with organochlorine (OC) pesticides. Vitellogenin was measured in 381 crocodile plasma samples using a vitellogenin ELISA previously developed for this species. Vitellogenin was detected in nine samples, all from adult females sampled during the breeding season. Males and juvenile females did not contain detectable levels of vitellogenin; however, many of these animals contained OC pesticides in their caudal scutes, confirming contaminant exposure. The lack of a vitellogenic response in these animals may be attributable to several factors related to the timing and magnitude of exposure to endocrine-disrupting chemicals and should not be interpreted as an absence of other contaminant-induced biological responses. - Wild crocodiles living in habitats polluted with organochlorine pesticides did not exhibit contaminant-induced vitellogenin induction in blood plasma

Extracellular histones identified in crocodile blood inhibit in-vitro HIV-1 infection.

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Kozlowski, Hannah N; Lai, Eric T L; Havugimana, Pierre C; White, Carl; Emili, Andrew; Sakac, Darinka; Binnington, Beth; Neschadim, Anton; McCarthy, Stephen D S; Branch, Donald R

2016-08-24

It has been reported that crocodile blood contains potent antibacterial and antiviral properties. However, its effects on HIV-1 infection remain unknown. We obtained blood from saltwater crocodiles to examine whether serum or plasma could inhibit HIV-1 infection. We purified plasma fractions then used liquid chromatography-mass spectrometry to identify the inhibitory protein factor(s). We then analyzed the ability of recombinant proteins to recapitulate HIV-1 inhibition and determine their mechanism of action. Crocodylus porosus plasma was tested for inhibition of Jurkat T-cell HIV-1 infection. Inhibitor(s) were purified by reverse-phase chromatography then identified by protein liquid chromatography-mass spectrometry. Anti-HIV-1 activity of purified plasma or recombinant proteins were measured by p24 enzyme-linked immunosorbent assay and luciferase readouts, and mechanism of action was determined by measuring HIV-1 RNA, cDNA and transcription (using 1G5 cells). Crocodile plasma contains potent inhibitors of HIV-1IIIB infection, which were identified as histones. Recombinant human histones H1 and H2A significantly reduced HIV-1JR-FL infection (IC50 of 0.79 and 0.45 μmol/l, respectively), whereas H4 enhanced JR-FL luciferase activity. The inhibitory effects of crocodile plasma, recombinant H1 or recombinant H2A on HIV-1 infection were during or post-viral transcription. Circulating histones in crocodile blood, possibly released by neutrophil extracellular traps, are significant inhibitors of HIV-1 infection in-vitro. Extracellular recombinant histones have different effects on HIV-1 transcription and protein expression and are downregulated in HIV-1 patients. Circulating histones may be a novel resistance factor during HIV-1 infection, and peptide versions should be explored as future HIV-1 therapeutics that modulate viral transcription.

Feeding alters blood flow patterns in the American alligator (Alligator mississippiensis).

Science.gov (United States)

Findsen, Anders; Crossley, Dane A; Wang, Tobias

2018-01-01

The crocodilian cardiovascular design with a four-chambered heart and a left aorta that emerge from the right ventricle allows blood to be shunted away from the lungs, a right-to-left (R-L) shunt. The adaptive significance of this R-L shunt remains both poorly understood and controversial with particular debate on its putative role during digestion. Here we measure blood flow patterns in the right aorta (RAo), left aorta (LAo) and the coeliac artery (CoA) of undisturbed American alligators (Alligator mississippiensis) during fasting and throughout most of the digestive period. Digestion doubled blood flow in the RAo (10.1±0.9 to 20.7±1.5mlmin -1 kg -1 ), whereas LAo increased approximately 3-fold (3.8±0.6 to 12.2±2.1mlmin -1 kg -1 ). Blood flow in the CoA increased more than four-fold during digestion (3.0±0.6 to 13.3±1.6mlmin -1 kg -1 ). The rise in blood flows was achieved by a doubling of heart rate (18.5±3.3 to 37.8±3.6mlmin -1 kg -1 ). Maximal flows measured in all arteries and heart rate occurred in the first hour of the postprandial period and continued for the next 7h. Copyright © 2017 Elsevier Inc. All rights reserved.

Siamese crocodile plasma synergizes with ceftazidime against ...

African Journals Online (AJOL)

Sent for review: 27 April 2017 ... Methods: Protein fractions were from crocodile plasma and tested them on CREnC strains. ... viability curves, membrane permeability assays, enzyme assays, and transmission electron microscopy. ... This is an Open Access article that uses a funding model which does not charge readers or ...

A new horned crocodile from the Plio-Pleistocene hominid sites at Olduvai Gorge, Tanzania.

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Christopher A Brochu

Full Text Available BACKGROUND: The fossil record reveals surprising crocodile diversity in the Neogene of Africa, but relationships with their living relatives and the biogeographic origins of the modern African crocodylian fauna are poorly understood. A Plio-Pleistocene crocodile from Olduvai Gorge, Tanzania, represents a new extinct species and shows that high crocodylian diversity in Africa persisted after the Miocene. It had prominent triangular "horns" over the ears and a relatively deep snout, these resemble those of the recently extinct Malagasy crocodile Voay robustus, but the new species lacks features found among osteolaemines and shares derived similarities with living species of Crocodylus. METHODOLOGY/PRINCIPAL FINDINGS: The holotype consists of a partial skull and skeleton and was collected on the surface between two tuffs dated to approximately 1.84 million years (Ma, in the same interval near the type localities for the hominids Homo habilis and Australopithecus boisei. It was compared with previously-collected material from Olduvai Gorge referable to the same species. Phylogenetic analysis places the new form within or adjacent to crown Crocodylus. CONCLUSIONS/SIGNIFICANCE: The new crocodile species was the largest predator encountered by our ancestors at Olduvai Gorge, as indicated by hominid specimens preserving crocodile bite marks from these sites. The new species also reinforces the emerging view of high crocodylian diversity throughout the Neogene, and it represents one of the few extinct species referable to crown genus Crocodylus.

PLASMA STEROID CONCENTRATIONS IN RELATION TO SIZE AND AGE IN JUVENILE ALLIGATORS FROM TWO FLORIDA LAKES.

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Previous studies have reported a number of physiological differences among juvenile alligators from two well-studied populations (Lake Apopka and Lake Woodruff) in north central Florida. These studies obtained alligators of similar size from each lake under the assumption that th...

The influence of regional hydrology on nesting behavior and nest fate of the American alligator

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Ugarte, Cristina A.; Bass, Oron L.; Nuttle, William; Mazzotti, Frank J.; Rice, Kenneth G.; Fujisaki, Ikuko; Whelan, Kevin R.T.

2013-01-01

Hydrologic conditions are critical to the nesting behavior and reproductive success of crocodilians. In South Florida, USA, growing human settlement has led to extensive surface water management and modification of historical water flows in the wetlands, which have affected regional nesting of the American alligator (Alligator mississippiensis). Although both natural and anthropogenic factors are considered to determine hydrologic conditions, the aspects of hydrological patterns that affect alligator nest effort, flooding (partial and complete), and failure (no hatchling) are unclear. We deconstructed annual hydrological patterns using harmonic models that estimated hydrological matrices including mean, amplitude, timing of peak, and periodicity of surface water depth and discharge and examined their effects on alligator nesting using survey data from Shark Slough, Everglades National Park, from 1985 to 2005. Nest effort increased in years with higher mean and lesser periodicity of water depth. A greater proportion of nests were flooded and failed when peak discharge occurred earlier in the year. Also, nest flooding rates were greater in years with greater periodicity of water depth, and nest failure rate was greater when mean discharge was higher. This study guides future water management decisions to mitigate negative impacts on reproduction of alligators and provides wildlife managers with a tool for assessing and modifying annual water management plans to conserve crocodilians and other wetland species.

Population assessment of the American crocodile, Crocodylus acutus (Crocodilia: Crocodylidae on the Pacific coast of Costa Rica

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Laurie A. Mauger

2012-12-01

Full Text Available The American crocodile, Crocodylus acutus, is widely distributed in the American neotropics. It is endangered throughout most of its range and is listed as vulnerable by the International Union for the Conservation of Natural Fauna and Flora (IUCN and on Appendix I of the Convention for the International Trade in Endangered Species of Wild Flora and Fauna (CITES. Despite this listing, there are few published reports on population status throughout most of its range. We investigated the status of the C. acutus, at several locations along the Pacific coast of Costa Rica. We carried out spotlight and nesting surveys from 2007-2009 along the Costa Rican Pacific coast in four distinct areas, coastal areas of Las Baulas (N=40 and Santa Rosa (N=9 National Parks and the Osa Conservation Area (N=13, and upriver in Palo Verde National Park (N=11. We recorded crocodile locations and standard environmental data at each observation. Encounter rates, population structure, distribution within each area and data on successful nesting (presence of hatchlings, nests, etc were determined. We attempted to capture all crocodiles to record standard morphometrics. A total of 586 crocodiles were observed along 185.8km of survey route. The majority of animals encountered (54.9% were either hatchlings (<0.5m or juveniles (0.5-1.25m. The average non-hatchling encounter rate per survey for the Pacific coast was 3.1 crocodiles/km, with individual encounter rates ranging from 1.2 crocodiles/km to 4.3 crocodiles/ km in Las Baulas National Park and the Osa Conservation Area respectively. Distribution of size classes within the individual locations did not differ with the exception of Santa Rosa and Las Baulas National Parks, where hatchlings were found in water with lower salinities. These were the first systematic surveys in several of the areas studied and additional work is needed to further characterize the American crocodile population in Costa Rica.

The oldest record of Alligator sinensis from the Late Pliocene of Western Japan, and its biogeographic implication

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Iijima, Masaya; Takahashi, Keiichi; Kobayashi, Yoshitsugu

2016-07-01

The late Cenozoic fossil record of alligators in East Asia is crucial in understanding the origin and past distribution of Asian alligators that are now represented by a single species, Alligator sinensis. This study reports a partial skeleton of A. sinensis from the Late Pliocene (approximately 3.0 Ma) of western Japan. This Japanese A. sinensis is large in size (>200 cm total length), comparable to the maximum size of extant individuals. It demonstrates the oldest record of A. sinensis and wider distribution of this species in the past. Tectonic and geographic history of East Asia suggests that alligators presumably dispersed into Japan before 25 Ma or after 10 Ma, yet finally were wiped out from Japan due to the semi-isolated condition of the Japanese island arc and the deteriorated climate during the Plio-Pleistocene.

Causes of environmental change in the Alligator Rivers region

International Nuclear Information System (INIS)

Skidmore, J.

1990-01-01

Covering some 28,000 square kilometres of the Northern Territory, the Alligator Rivers Region (ARR) includes the catchments of the East, South and West Alligator Rivers, and many small abandoned uranium mines. To introduce the problems of human impact on the ARR, the toxicologically significant aspects of the local environment were first examined, then the possible effects on it of mining and other human activities. It was found that the most deleterious impact on the region is not caused by mining but by human settlement, introduction of animals (notably the buffalo) and plants, the use of fire and tourism

Life histories and conservation of long-lived reptiles, an illustration with the American crocodile (Crocodylus acutus)

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Briggs-Gonzalez, Venetia; Bonefant, Christophe; Basille, Mathieu; Cherkiss, Michael S.; Beauchamp, Jeff; Mazzotti, Frank J.

2017-01-01

Successful species conservation is dependent on adequate estimates of population dynamics, but age-specific demographics are generally lacking for many long-lived iteroparous species such as large reptiles. Accurate demographic information allows estimation of population growth rate, as well as projection of future population sizes and quantitative analyses of fitness trade-offs involved in the evolution of life-history strategies.Here, a long-term capture–recapture study was conducted from 1978 to 2014 on the American crocodile (Crocodylus acutus) in southern Florida. Over the study period, 7,427 hatchlings were marked and 380 individuals were recaptured for as many as 25 years. We estimated survival to be strongly age dependent with hatchlings having the lowest survival rates (16%) but increasing to nearly 90% at adulthood based on mark–recapture models. More than 5% of the female population were predicted to be reproductive by age 8 years; the age-specific proportion of reproductive females steadily increased until age 18 when more than 95% of females were predicted to be reproductive. Population growth rate, estimated from a Leslie–Lefkovitch stage-class model, showed a positive annual growth rate of 4% over the study period.Using a prospective sensitivity analysis, we revealed that the adult stage, as expected, was the most critical stage for population growth rate; however, the survival of younger crocodiles before they became reproductive also had a surprisingly high elasticity. We found that variation in age-specific fecundity has very limited impact on population growth rate in American crocodiles.We used a comparative approach to show that the original life-history strategy of American crocodiles is actually shared by other large, long-lived reptiles: while adult survival rates always have a large impact on population growth, this decreases with declining increasing growth rates, in favour of a higher elasticity of the juvenile stage.Crocodiles, as

Fulltext PDF

Indian Academy of Sciences (India)

determined and the 1:1 sex ratio is maintained. In many species of reptiles, environmental factors such as temperature play an important role in determining the sex ratio (Head et al. 1987). For example, in alligators, crocodiles and turtles, during the early stages of embryogenesis, temperature has a determining effect on the ...

Umbilical scarring in hatchling American alligators

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Wiebe, J.J.; Sepulveda, M.S.; Buckland, J.E.; Anderson, S.R.; Gross, T.S.

2004-01-01

Umbilical scarring is the presence of excess scar tissue deposited between abdominal dermal layers at the site of yolk sac absorption in hatchling American alligators (Alligator mississippiensis). The presence of this dermal condition plays a key evaluatory role in the overall quality and subsequent value for various commercial leather products. Despite the prevalent nature of this condition, currently the industry has no standardized protocols for its quantification. The objectives of this study were to examine the relationship between hatchling weight and age and incidence of umbilical scarring and to develop a quantifiable and reproducible technique to measure this dermal condition in hatchling American alligators. Thirty eggs from each of nine clutches were incubated in two separate incubators at different facilities and hatchling umbilical scarring was measured at 2 and 10 days of age using digital calipers. Umbilical area was calculated by multiplying umbilical length times umbilical width. There was a significant effect of both age and clutch on umbilical area (overall decline of 64%) by 10 days post-hatch. However, only five of the nine clutches utilized expressed a noticeable decline in the size of this dermal condition (range 67-74%). We had hypothesized that larger hatchlings would have larger umbilical areas and a slower rate of improvement in this condition during the first few days post-hatch. The differences in umbilical area and percent decline with age across clutches, however, were not associated with differences in initial hatchling weights. Within clutches and time periods, hatchling weight had no significant effect on the size and/or rate of decline of this condition. ?? 2004 Published by Elsevier B.V.

Mercury and metallothioneins in blood fractions and tissues of captive Morelet's crocodiles in Quintana Roo, Mexico.

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Buenfil-Rojas, A M; Alvarez-Legorreta, T; Cedeño-Vázquez, J R

2018-05-01

Even though studies of heavy metals and their relation with metallothioneins (MTs) in reptile tissues have been conducted, research on heavy metals and MTs in organs and blood fractions of crocodylians is limited. To date there are no studies on the distribution of MTs in organs and their relation with mercury (Hg), or the concentration of MTs in plasma and erythrocytes of crocodylians. In order to understand the role of MTs in crocodiles, our aim was to assess the detoxification mechanisms for exposure to metals in Morelet's crocodile (Crocodylus moreletii) by using two biomarkers (Hg and MTs) in blood fractions and tissues, and comparing them with concentrations between two populations of crocodiles, one previously wild and currently captive (Theme Park) and another raised in a Wildlife Management Unit (WMU). The caudal scutes from the Theme Park showed higher concentrations of Hg than those from the skin in the WMU samples, and significant negative relationships were observed between the total length (TL) and Hg in the scutes. The significant negative relationship between Hg and hemoglobin (Hb) may be due to disorders in the oxidation process and even denature of this protein, while the positive trend observed between MTs and Hb is consistent with the detoxifying functions and the protection against oxidative damage. This study is the first to report Hg in the erythrocytes of crocodylians and the use of MTs for testing the potential of these biomarkers as a tool to assess Hg exposure in crocodile's habitats. Copyright © 2018 Elsevier Ltd. All rights reserved.

Reassessment of genome size in turtle and crocodile based on chromosome measurement by flow karyotyping: close similarity to chicken

Science.gov (United States)

Kasai, Fumio; O'Brien, Patricia C. M.; Ferguson-Smith, Malcolm A.

2012-01-01

The genome size in turtles and crocodiles is thought to be much larger than the 1.2 Gb of the chicken (Gallus gallus domesticus, GGA), according to the animal genome size database. However, GGA macrochromosomes show extensive homology in the karyotypes of the red eared slider (Trachemys scripta elegans, TSC) and the Nile crocodile (Crocodylus niloticus, CNI), and bird and reptile genomes have been highly conserved during evolution. In this study, size and GC content of all chromosomes are measured from the flow karyotypes of GGA, TSC and CNI. Genome sizes estimated from the total chromosome size demonstrate that TSC and CNI are 1.21 Gb and 1.29 Gb, respectively. This refines previous overestimations and reveals similar genome sizes in chicken, turtle and crocodile. Analysis of chromosome GC content in each of these three species shows a higher GC content in smaller chromosomes than in larger chromosomes. This contrasts with mammals and squamates in which GC content does not correlate with chromosome size. These data suggest that a common ancestor of birds, turtles and crocodiles had a small genome size and a chromosomal size-dependent GC bias, distinct from the squamate lineage. PMID:22491763

Plasma vitellogenin in Morelet's crocodiles from contaminated habitats in northern Belize

Energy Technology Data Exchange (ETDEWEB)

Rainwater, Thomas R. [Institute of Environmental and Human Health and Department of Environmental Toxicology, Texas Tech University, Box 41163, Lubbock, TX 79409-1163 (United States)], E-mail: thomas.rainwater@gmail.com; Selcer, Kyle W. [Department of Biological Sciences, Bayer School of Natural and Environmental Sciences, Duquesne University, Pittsburgh, PA 15282 (United States)], E-mail: selcer@duq.edu; Nespoli, Lisa M. [Department of Biological Sciences, Bayer School of Natural and Environmental Sciences, Duquesne University, Pittsburgh, PA 15282 (United States)], E-mail: nespoli345@duq.edu; Finger, Adam G. [Institute of Environmental and Human Health and Department of Environmental Toxicology, Texas Tech University, Box 41163, Lubbock, TX 79409-1163 (United States)], E-mail: agfinger@tiehh.ttu.edu; Ray, David A. [Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409 (United States)], E-mail: david.ray@mail.wvu.edu; Platt, Steven G. [Department of Biology, P.O. Box C-64, Sul Ross State University, Alpine, TX 79832 (United States)], E-mail: splatt@sulross.edu; Smith, Philip N. [Institute of Environmental and Human Health and Department of Environmental Toxicology, Texas Tech University, Box 41163, Lubbock, TX 79409-1163 (United States)], E-mail: philip.smith@tiehh.ttu.edu; Densmore, Llewellyn D. [Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409 (United States)], E-mail: lou.densmore@ttu.edu; Anderson, Todd A. [Institute of Environmental and Human Health and Department of Environmental Toxicology, Texas Tech University, Box 41163, Lubbock, TX 79409-1163 (United States)], E-mail: todd.anderson@tiehh.ttu.edu; McMurry, Scott T. [Institute of Environmental and Human Health and Department of Environmental Toxicology, Texas Tech University, Box 41163, Lubbock, TX 79409-1163 (United States)], E-mail: scott.mcmurry@tiehh.ttu.edu

2008-05-15

Vitellogenin induction has been widely used as a biomarker of endocrine disruption in wildlife, but few studies have investigated its use in wild reptiles living in contaminated habitats. This study examined vitellogenin induction in Morelet's crocodiles (Crocodylus moreletii) from wetlands in northern Belize contaminated with organochlorine (OC) pesticides. Vitellogenin was measured in 381 crocodile plasma samples using a vitellogenin ELISA previously developed for this species. Vitellogenin was detected in nine samples, all from adult females sampled during the breeding season. Males and juvenile females did not contain detectable levels of vitellogenin; however, many of these animals contained OC pesticides in their caudal scutes, confirming contaminant exposure. The lack of a vitellogenic response in these animals may be attributable to several factors related to the timing and magnitude of exposure to endocrine-disrupting chemicals and should not be interpreted as an absence of other contaminant-induced biological responses. - Wild crocodiles living in habitats polluted with organochlorine pesticides did not exhibit contaminant-induced vitellogenin induction in blood plasma.

Water hyacinths and alligator weeds for removal of silver, cobalt, and strontium from polluted waters

Science.gov (United States)

Wolverton, B. C.; Mcdonald, R. C.

1975-01-01

Water hyacinths and alligator weeds demonstrated the ability to rapidly remove heavy metals from an aqueous system by root absorption and concentration. Water hyacinths demonstrated the ability to remove 0.439 mg of silver, 0.568 mg of cobalt, and 0.544 mg of strontium in an ionized form per gram of dry plant material in a 24-hour period. Alligator weeds removed a maximum of 0.439 mg of silver, 0.130 mg of cobalt, and 0.161 mg of strontium per gram of dry plant material per day.

Implications of skull shape for the ecology and conservation biology of crocodiles

NARCIS (Netherlands)

Pearcy, Ashley

2011-01-01

Each species of crocodile has its own distinct head shape with its own well-adapted capacities for movement, force, strength, and in turn diet and habitat preferences suiting their niche. Different species of crocodilians with overlapping or matching natural ranges (sympatric species) show increased

Analysis of Siamese Crocodile (Crocodylus siamensis) Eggshell Proteome

Czech Academy of Sciences Publication Activity Database

Mikšík, Ivan; Pataridis, Statis; Eckhardt, Adam; Sedmera, David

2018-01-01

Roč. 37, č. 1 (2018), s. 21-37 ISSN 1572-3887 R&D Projects: GA ČR(CZ) GA15-01948S; GA ČR(CZ) GA16-02972S Institutional support: RVO:67985823 Keywords : protein s of eggshell * eggshell pigment * crocodile Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 1.139, year: 2016

Multiple spinal curvatures in a captive African dwarf crocodile ...

African Journals Online (AJOL)

A 4 year old African dwarf crocodile that had been domiciled at the Zoological Gardens, University of Ibadan for 2 years was presented with a history of anorexia of two weeks' duration and reluctance to move for about a week prior to presentation. Physical examination revealed body curvatures and radiography was ...

Quantitative analysis of production traits in saltwater crocodiles (Crocodylus porosus): II. age at slaughter.

Science.gov (United States)

Isberg, S R; Thomson, P C; Nicholas, F W; Barker, S G; Moran, C

2005-12-01

Crocodile morphometric (head, snout-vent and total length) measurements were recorded at three stages during the production chain: hatching, inventory [average age (+/-SE) is 265.1 +/- 0.4 days] and slaughter (average age is 1037.8 +/- 0.4 days). Crocodile skins are used for the manufacture of exclusive leather products, with the most common-sized skin sold having 35-45 cm in belly width. One of the breeding objectives for inclusion into a multitrait genetic improvement programme for saltwater crocodiles is the time taken for a juvenile to reach this size or age at slaughter. A multivariate restricted maximum likelihood analysis provided (co)variance components for estimating the first published genetic parameter estimates for these traits. Heritability (+/-SE) estimates for the traits hatchling snout-vent length, inventory head length and age at slaughter were 0.60 (0.15), 0.59 (0.12) and 0.40 (0.10) respectively. There were strong negative genetic (-0.81 +/- 0.08) and phenotypic (-0.82 +/- 0.02) correlations between age at slaughter and inventory head length.

Differential protein expression in alligator leukocytes in response to bacterial lipopolysaccharide injection.

Science.gov (United States)

Merchant, Mark; Kinney, Clint; Sanders, Paige

2009-12-01

Blood was collected from three juvenile alligators (Alligator mississippiensis) before, and again 24h after, injection with bacterial lipopolysaccharide (LPS). The leukocytes were collected from both samples, and the proteins were extracted. Each group of proteins was labeled with a different fluorescent dye and the differences in protein expression were analyzed by two dimensional differential in-gel expressions (2D-DIGE). The proteins which appeared to be increased or decreased by treatment with LPS were selected and analyzed by MALDI-TOF to determine mass and LC-MS/MS to acquire the partial protein sequences. The peptide sequences were compared to the NCBI protein sequence database to determine homology with other sequences from other species. Several proteins of interest appeared to be increased upon LPS stimulation. Proteins with homology to human transgelin-2, fish glucose-6-phosphate dehydrogenase, amphibian α-enolase, alligator lactate dehydrogenase, fish ubiquitin-activating enzyme, and fungal β-tubulin were also increased after LPS injection. Proteins with homology to fish vimentin 4, murine heterogeneous nuclear ribonucleoprotein A3, and avian calreticulin were found to be decreased in response to LPS. In addition, five proteins, four of which were up-regulated (827, 560, 512, and 650%) and one that exhibited repressed expression (307%), did not show homology to any protein in the database, and thus may represent newly discovered proteins. We are using this biochemical approach to isolate and characterize alligator proteins with potential relevant immune function.

Biotransformation and Oxidative Stress Responses in Captive Nile Crocodile (Crocodylus niloticus Exposed to Organic Contaminants from the Natural Environment in South Africa.

Directory of Open Access Journals (Sweden)

Augustine Arukwe

Full Text Available In the present study, the biotransformation and oxidative stress responses in relation to chemical burden in the liver of male and female Nile crocodiles--Crocodylus niloticus--from a commercial crocodile farm passively exposed to various anthropogenic aquatic pollutants was investigated. In general, the data showed that male crocodiles consistently produced higher biotransformation and oxidative stress responses compared to females. Relationships between these responses and concentrations of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs were also observed. Specifically, the catalytic assays for EROD and BROD (not PROD and MROD showed sex-differences between male and female crocodiles and paralleled immunochemically determined CYP1A and CYP3A protein levels; the relatively similar levels of PAHs in both sexes suggest an estrogen-mediated reduction of this pathway in females. The antioxidant system exhibited higher levels in male crocodiles with slight or significant higher values for catalase (CAT, glutathione reductase (GR, glutathione peroxidases-H2O2 (GPx-H2O2, glutathione peroxidases-Cu (GPx-Cu, total antioxidant capacity towards peroxyl radicals (TOSC-ROO and hydroxyl radicals (TOSC-HO, total glutathione (GSH and malondialdehyde (MDA. On the other hand, the activities of acyl-CoA oxidase (AOX and glutathione S-transferases (GST were significantly higher in females. Principal component analysis (PCA produced significant groupings that revealed correlative relationships (both positive and negative between biotransformation/oxidative stress variables and liver PAHs and aliphatic hydrocarbon burden. The overall results suggest that these captive pre-slaughter crocodiles exhibited adverse exposure responses to anthropogenic aquatic contaminants with potentially relevant effects on key cellular pathways, and these responses may be established as relevant species biomarkers of exposure and effects in this endangered species.

Gulf-Wide Information System, Environmental Sensitivity Index Alligator Database, Geographic NAD83, LDWF (2001) [esi_gator_LDWF_2001

Data.gov (United States)

Louisiana Geographic Information Center — This data set contains sensitive biological resource data for American alligator in coastal Louisiana. Vector polygons represent alligator habitats with nest density...

Effect of alligator pepper (Zingiberaceae Aframomum melegueta ...

African Journals Online (AJOL)

Fifteen male rats and fifteen female rats of proven fertility from a pilot study were randomly paired in fifteen cages in a well ventillated room. After three days of mating, the males were withdrawn from ... risk to women in their first trimester of pregnancy. Key words : Effect, Alligator pepper, Herbal remedy, Nutrition, Pregnancy ...

Environment Protection (Alligator Rivers Region) Amendment Act 1987 - No 17 of 1987

International Nuclear Information System (INIS)

1987-01-01

This Act amends the Environment Protection (Alligator Rivers Region) Act 1978. The amendments mainly concern definition of general mining operations and specification of the functions of the Supervisory Scientist and the Research Institute in relation to general mining in an environment conservation zone (parts of the Alligator Rivers Region). The 1978 Act provided for the appointment of a Supervising Scientist responsible for supervising protection of the environment against the effects of uranium mining in the Region, and for the creation of a Research Institute under his management. (NEA) [fr

Heterophil/Lymphocyte Alterations as a Measure of Stress in American Alligators in Relation to Anthropogenic Disturbance in a Louisiana Intermediate Marsh

Directory of Open Access Journals (Sweden)

Christopher M. Murray

2015-05-01

Full Text Available Numerous anthropogenic factors represent environmental threats to Gulf Coast wetland ecosystems and associated fauna. American alligators (Alligator mississippiensis have been subject to long-term management and used as ecological and physiological indicators of habitat quality in response to anthropogenic events and stochastic natural disasters. The present study monitored heterophil to lymphocyte ratios (an indicator of stress, in American alligators in a Louisiana intermediate marsh from 2009 to 2011, a time period that coincides with an oil inundation event that occurred in 2011. Sixteen alligators were observed and processed morphometrically (total length, snout-vent length and body mass. Heterophil to lymphocyte ratios were negatively correlated with size, suggesting larger American alligators were physiologically more resilient to the disturbance, more able to actively avoid these poor conditions, or are less affected by localized disturbance.

Up-regulation of the alligator CYP3A77 gene by toxaphene and dexamethasone and its short term effect on plasma testosterone concentrations

International Nuclear Information System (INIS)

Gunderson, M.P.; Kohno, S.; Blumberg, B.; Iguchi, T.; Guillette, L.J.

2006-01-01

In this study we describe an alligator hepatic CYP3A gene, CYP3A77, which is inducible by dexamethasone and toxaphene. CYP3A plays a broad role in biotransforming both exogenous compounds and endogenous hormones such as testosterone and estradiol. Alligators collected from sites in Florida that are contaminated with organochlorine compounds exhibit differences in sex steroid concentrations. Many organochlorine compounds induce CYP3A expression in other vertebrates; hence, CYP3A induction by organochlorine contaminants could increase biotransformation and clearance of sex steroids by CYP3A and provide a plausible mechanism for the lowering of endogenous sex steroid concentrations in alligator plasma. We used real time PCR to examine whether known and suspected CYP3A inducers (dexamethasone, metyrapone, rifampicin, and toxaphene) up-regulate steady state levels of hepatic CYP3A77 transcript to determine if induction patterns in female juvenile alligators are similar to those reported in other vertebrates and whether toxaphene, an organochlorine compound found in high concentrations in Lake Apopka alligators, induces this gene. Estrogen receptor α (ERα), estrogen receptor β (ERβ), androgen receptor (AR), glucocorticoid receptor (GR), progesterone receptor (PR), and steroid-xenobiotic receptor (SXR) transcripts were also measured to determine whether any of these nuclear receptors are also regulated by these compounds in alligators. Dexamethasone (4.2-fold) and toxaphene (3.5-fold) significantly induced CYP3A77 gene transcript, whereas rifampicin (2.8-fold) and metyrapone (2.1-fold) up-regulated ERβ after 24 h. None of the compounds significantly up-regulated AR, ERα, GR, PR, or SXR over this time period. Plasma testosterone (T) did not change significantly after 24 h in alligators from any of the treatment groups. Dexamethasone treated animals exhibited a strong relationship between the 24 h plasma T concentrations and CYP3A77 (R 2 = 0.9, positive) and SXR (R 2

Estimating spawning times of Alligator Gar (Atractosteus spatula) in Lake Texoma, Oklahoma

Science.gov (United States)

Snow, Richard A.; Long, James M.

2015-01-01

In 2013, juvenile Alligator Gar were sampled in the reservoir-river interface of the Red River arm of Lake Texoma. The Red River, which flows 860 km along Oklahoma’s border with Texas, is the primary in-flow source of Lake Texoma, and is impounded by Denison Dam. Minifyke nets were deployed using an adaptive random cluster sampling design, which has been used to effectively sample rare species. Lapilli otoliths (one of the three pair of ear stones found within the inner ear of fish) were removed from juvenile Alligator Gar collected in July of 2013. Daily ages were estimated by counting the number of rings present, and spawn dates were back-calculated from date of capture and subtracting 8 days (3 days from spawn to hatch and 5 days from hatch to swimup when the first ring forms). Alligator Gar daily age estimation ranged from 50 to 63 days old since swim-up. Spawn dates corresponded to rising pool elevations of Lake Texoma and water pulses of tributaries.

Osteoarthropathy of unknown aetiology in the long bones of farmed and wild Nile crocodiles (Crocodylus niloticus

Directory of Open Access Journals (Sweden)

Fritz W. Huchzermeyer

2013-11-01

Full Text Available Humeri of farmed and wild Nile crocodiles (Crocodylus niloticus collected during routine post-mortem examinations were boiled, cleaned and examined for lesions. Various degrees of gross bone and articular pathology were found. The lesions were situated predominantly at the proximal and distal epiphyseal and metaphyseal regions of the bone, where growth and bone remodelling occurs. In advanced cases partial collapse of the articular surface could be identified. From the collection of crocodile bones five particular cases are described. Because of the wide distribution of origin of the affected animals, nutritional or toxicological causes seem unlikely. One of the cases presented was associated with mycoplasmosis. These forms of crocodilian bone pathology need further investigation.

Aeromonas hydrophila-associated skin lesions and septicaemia in a Nile crocodile (Crocodylus niloticus : clinical communication

Directory of Open Access Journals (Sweden)

H. Turutoglu

2005-06-01

Full Text Available Aeromonas hydrophila is one of the most common bacteria associated with the aquatic environment. There are , however, limited data on A. hydrophila infection in crocodilians. The aim of this report is to describe a case of skin lesions and septicaemia associated with A. hydrophila in a Nile crocodile (Crocodylus niloticus. A captive male crocodile in the Zoological Park of Antalya (Turkey was found dead without showing signs of any disease. Gross examination showed brown or red-spotted skin lesions of varying size. These lesions were mostly scattered over the abdomen and occasionally on the tail and feet. At necropsy, numerous white, multifocal and randomly distributed areas were seen on the liver. Gram-stained smears from skin and liver lesions showed Gram-negative bacilli arranged in clusters. Pure cultures of A. hydrophila were recovered from skin, internal organs and blood. Isolates were found to be susceptible to ceftiofur, amoxicillin + clavulanic acid, oxytetracycline, enrofloxacin, danofloxacin, neomycin, gentamicin, and lincomycin + neomycin. A pathogenicity test was performed using this isolate on 4 male 2-year-old New Zealand white rabbits. Local abscesses formed in 2 rabbits injected subcutaneously and the 2 that were injected intraperitoneally died as a result of septicaemia. In conclusion, this report has shown that A. hydrophila may cause skin lesions and even death due to septicaemia in crocodiles.

Effect of aqueous extract of alligator pepper (Zingiberaceae ...

African Journals Online (AJOL)

Twenty female and ten male Sprague-Dawley rats of proven fertility from a pilot study were randomly mated in groups of two females and one male. Three days later, female rats in the ... weight gain reduction. Key words: Gestational weight gain, Aqueous Extract, Intra-peritoneal injection, Alligator Pepper, Nutrition.

A genetic linkage map for the saltwater crocodile (Crocodylus porosus

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Lance Stacey L

2009-07-01

Full Text Available Abstract Background Genome elucidation is now in high gear for many organisms, and whilst genetic maps have been developed for a broad array of species, surprisingly, no such maps exist for a crocodilian, or indeed any other non-avian member of the Class Reptilia. Genetic linkage maps are essential tools for the mapping and dissection of complex quantitative trait loci (QTL, and in order to permit systematic genome scans for the identification of genes affecting economically important traits in farmed crocodilians, a comprehensive genetic linage map will be necessary. Results A first-generation genetic linkage map for the saltwater crocodile (Crocodylus porosus was constructed using 203 microsatellite markers amplified across a two-generation pedigree comprising ten full-sib families from a commercial population at Darwin Crocodile Farm, Northern Territory, Australia. Linkage analyses identified fourteen linkage groups comprising a total of 180 loci, with 23 loci remaining unlinked. Markers were ordered within linkage groups employing a heuristic approach using CRIMAP v3.0 software. The estimated female and male recombination map lengths were 1824.1 and 319.0 centimorgans (cM respectively, revealing an uncommonly large disparity in recombination map lengths between sexes (ratio of 5.7:1. Conclusion We have generated the first genetic linkage map for a crocodilian, or indeed any other non-avian reptile. The uncommonly large disparity in recombination map lengths confirms previous preliminary evidence of major differences in sex-specific recombination rates in a species that exhibits temperature-dependent sex determination (TSD. However, at this point the reason for this disparity in saltwater crocodiles remains unclear. This map will be a valuable resource for crocodilian researchers, facilitating the systematic genome scans necessary for identifying genes affecting complex traits of economic importance in the crocodile industry. In addition

Plasma catecholamines and plasma corticosterone following restraint stress in juvenile alligators.

Science.gov (United States)

Lance, V A; Elsey, R M

1999-05-01

Ten juvenile alligators, mean body mass 793 g, hatched from artificially incubated eggs and raised under controlled conditions, were held out of water with their jaws held closed for 48 hr. An initial blood sample was taken and further samples collected at 1, 2, 4, 8, 24, and 48 hr. Epinephrine, norepinephrine, and dopamine were measured in plasma aliquots of 1.5 ml using high pressure liquid chromatography with electrochemical detection. Corticosterone was measured by radioimmunoassay. Plasma glucose was measured using the Trinder method and plasma calcium, cholesterol, and triglycerides were measured in an autoanalyzer. Epinephrine was about 4 ng/ml at the initial bleed, but declined steadily to blood cells showed changes indicating immune system suppression. By the end of the treatment the hetorophil/lymphocyte ratio increased to 4.7. These results suggest that handling alligators, taking multiple blood samples, and keeping them restrained for more than 8 hr is a severe stress to the animals.

Organochlorine pesticides and thiamine in eggs of largemouth bass and American alligators and their relationship with early life-stage mortality

Science.gov (United States)

Sepulveda, M.S.; Wiebe, J.J.; Honeyfield, D.C.; Rauschenberger, H.R.; Hinterkopf, J.P.; Johnson, W.E.; Gross, T.S.

2004-01-01

Thiamine deficiency has been linked to early mortality syndrome in salmonids in the Great Lakes. This study was conducted to compare thiamine concentrations in American alligators (Alligator mississippiensis) and Florida largemouth bass (Micropterus salmoides floridanus) eggs from sites with high embryo mortality and high exposure to organochlorine pesticides (OCPs) (Lakes Apopka and Griffin, and Emeralda Marsh, Florida, USA) to those from sites that have historically exhibited low embryo mortality and low OCPs (Lakes Woodruff and Orange, Florida). During June-July 2000, 20 alligator clutches were collected from these sites, artificially incubated, and monitored for embryo mortality. Thiamine and OCPs were measured in one egg/clutch. During February 2002, 10 adult female bass were collected from Emeralda Marsh and Lake Woodruff and mature ovaries analyzed for thiamine and OCP concentrations. Although ovaries from the Emeralda Marsh bass contained almost 1,000-fold more OCPs compared with the reference site, Lake Woodruff, there were no differences in thiamine concentrations between sites (11,710 vs. 11,857 pmol/g). In contrast, alligator eggs from the reference site had five times the amount of thiamine compared with the contaminated sites (3,123 vs. 617 pmol/g). Similarly, clutches with > 55% hatch rates had significantly higher concentrations of thiamine compared with clutches with eggs. ?? Wildlife Disease Association 2004.

Percutaneous antegrade ureteric stent removal using a rigid alligator forceps.

LENUS (Irish Health Repository)

Given, M F

2008-12-01

To evaluate the safety and efficacy of percutaneous antegrade ureteric stent removal using a rigid alligator forceps. Twenty patients were included in our study. Indications for ureteric stent insertion included stone disease (n = 7), malignancy (n = 8) and transplant anastomotic strictures (n = 5). Stent retrieval was carried out for proximal stent placement\\/migration in seven patients and encrustation in the remaining 13. Twenty-two stents were successfully retrieved in 20 patients. There was one technical failure (5%). There were no major complications. We had four minor complications, which included nephrostomy site pain (n = 2), periprocedural sepsis (n = 1) and a small urinoma (n = 1). All patients settled with conservative management. Percutaneous radiologically guided antegrade ureteric stent removal with an alligator forceps is safe and effective, particularly when initial surgical removal has failed.

Ecosystem change and the Olifants River crocodile mass mortality events

CSIR Research Space (South Africa)

Woodborne, S

2012-10-01

Full Text Available ) and the Crocodile River (25823057.100 S, 31857029.900 E) (site CR). Sharptooth catfish and tiger fish were caught on baited hooks or artificial lures, while other species were sampled using an electrofisher (Samus). The fish that were subject to isotopic... analysis comprise a subsample of the June 2011 collection from the OL, LR and CR sites. Invertebrates, diatoms, riparian and aquatic vegetation, sediments and organic detritus were also sampled for isotopic analysis. On 4?7 September 2011 tiger fish...

Blow Flies Visiting Decaying Alligators: Is Succession Synchronous or Asynchronous?

Directory of Open Access Journals (Sweden)

Mark P. Nelder

2009-01-01

Full Text Available Succession patterns of adult blow flies (Diptera: Calliphoridae on decaying alligators were investigated in Mobile (Ala, USA during August 2002. The most abundant blow fly species visiting the carcasses were Chrysomya rufifacies (Macquart, Cochliomyia macellaria (Fabricus, Chrysomya megacephala (Fabricus, Phormia regina (Meigen, and Lucilia coeruleiviridis (Macquart. Lucilia coeruleiviridis was collected more often during the early stages of decomposition, followed by Chrysomya spp., Cochliomyia macellaria, and Phormia regina in the later stages. Lucilia coeruleiviridis was the only synchronous blow fly on the three carcasses; other blow fly species exhibited only site-specific synchrony. Using dichotomous correlations and analyses of variance, we demonstrated that blow fly-community succession was asynchronous among three alligators; however, Monte Carlo simulations indicate that there was some degree of synchrony between the carcasses.

Population genetics implications for the conservation of the Philippine Crocodile Crocodylus mindorensis Schmidt, 1935 (Crocodylia: Crocodylidae)

OpenAIRE

M.R.P. Hinlo; J.A.G. Tabora; C.A. Bailey; S. Trewick; G. Rebong; M.V. Weerd; C.C. Pomares; S.E. Engberg; R.A. Brenneman; E.E. Louis, Jr.

2014-01-01

Limited information is available on the Philippine Crocodile, Crocodylus mindorensis, concerning levels of genetic diversity either relative to other crocodilian species or among populations of the species itself. With only two known extant populations of C. mindorensis remaining, potentially low levels of genetic diversity are a conservation concern. Here, we evaluated 619 putative Philippine Crocodiles using a suite of 11 microsatellite markers, and compared them to four other crocodilian s...

Sacrificing Steve: How I Killed the Crocodile Hunter

Directory of Open Access Journals (Sweden)

Luke Carman

2010-09-01

Full Text Available Bob Hodge and Vijay Mishra argue that the complex issues of illegitimacy at the core of Australian identity are repressed through a continual process of cyclical silencing, where traces of a shameful past are exorcised by a focus on images of a mythologised ‘legend’, embodied in characters such as 'The Man from Snowy River'. This article explores such a 'schizophrenic' cycle in relation to the life, death and resurrection of Steve 'Crocodile Hunter' Irwin.

General morphology of the oral cavity of the Nile crocodile, Crocodylus niloticus (Laurenti, 1768. I. Palate and gingivae

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J.F. Putterill

2003-11-01

Full Text Available The heads of nine 2.5 to 3-year-old Nile crocodiles (Crocodylus niloticus were obtained from a commercial farm where crocodiles are raised for their skins and meat. The animals from which these specimens originated were clinically healthy at the time they were slaughtered. A detailed description of the macroscopic and microscopic features of the palate and gingivae of the Nile crocodile is presented and the results are compared with published information on this species and other Crocodylia. The histological features are supplemented by information supplied by scanning electron microscopy. Macroscopic features of interest are the small conical process situated at the base of the first two incisors of the maxilla, the distribution of cobbled units on the palate, and the broad dentary shelf forming the rostral aspect of the mandible. Histologically the palate and gingivae did not differ significantly from each other and both regions showed a presence of Pacinian-type corpuscles. Two types of sensory structures (taste receptors and pressure receptors were identified in the regions examined, both involving modification of the epithelium and the underlying connective tissue.

Alligator Rivers Regions Research Institute research report 1983-84

International Nuclear Information System (INIS)

1984-01-01

The Institute undertakes and coordinates research required to ensure the protection of the environment in the Alligator Rivers Region from any consequences resulting from the mining and processing of uranium ore. Research projects outlined are in aquatic biology, terrestrial ecology, analytical chemistry, environmental radioactivity and geomorphology

Biotransformation and Oxidative Stress Responses in Captive Nile Crocodile (Crocodylus niloticus) Exposed to Organic Contaminants from the Natural Environment in South Africa

Science.gov (United States)

Arukwe, Augustine; Røsbak, Randi; Adeogun, Aina O.; Langberg, Håkon A.; Venter, Annette; Myburgh, Jan; Botha, Christo; Benedetti, Maura; Regoli, Francesco

2015-01-01

In the present study, the biotransformation and oxidative stress responses in relation to chemical burden in the liver of male and female Nile crocodiles—Crocodylus niloticus—from a commercial crocodile farm passively exposed to various anthropogenic aquatic pollutants was investigated. In general, the data showed that male crocodiles consistently produced higher biotransformation and oxidative stress responses compared to females. Relationships between these responses and concentrations of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were also observed. Specifically, the catalytic assays for EROD and BROD (not PROD and MROD) showed sex-differences between male and female crocodiles and paralleled immunochemically determined CYP1A and CYP3A protein levels; the relatively similar levels of PAHs in both sexes suggest an estrogen-mediated reduction of this pathway in females. The antioxidant system exhibited higher levels in male crocodiles with slight or significant higher values for catalase (CAT), glutathione reductase (GR), glutathione peroxidases-H2O2 (GPx-H2O2), glutathione peroxidases-Cu (GPx-Cu), total antioxidant capacity towards peroxyl radicals (TOSC-ROO) and hydroxyl radicals (TOSC-HO), total glutathione (GSH) and malondialdehyde (MDA). On the other hand, the activities of acyl-CoA oxidase (AOX) and glutathione S-transferases (GST) were significantly higher in females. Principal component analysis (PCA) produced significant groupings that revealed correlative relationships (both positive and negative) between biotransformation/oxidative stress variables and liver PAHs and aliphatic hydrocarbon burden. The overall results suggest that these captive pre-slaughter crocodiles exhibited adverse exposure responses to anthropogenic aquatic contaminants with potentially relevant effects on key cellular pathways, and these responses may be established as relevant species biomarkers of exposure and effects in this endangered species. PMID

Hepatic and renal concentrations of 10 trace elements in crocodiles (Crocodylus niloticus) in the Kafue and Luangwa rivers in Zambia

Energy Technology Data Exchange (ETDEWEB)

Almli, Bjorn [National Veterinary Institute, POB 8156 Dep., N-0033 Oslo (Norway)]. E-mail: bjorn.almli@vetinst.no; Mwase, Maxwell [Samora Machel School of Veterinary Medicine, University of Zambia, POB 32379, Lusaka (Zambia); Sivertsen, Tore [Norwegian School of Veterinary Science, POB 8146 Dep., N-0033 Oslo (Norway); Musonda, Mike [Samora Machel School of Veterinary Medicine, University of Zambia, POB 32379, Lusaka (Zambia); Flaoyen, Arne [National Veterinary Institute, POB 8156 Dep., N-0033 Oslo (Norway); Norwegian School of Veterinary Science, POB 8146 Dep., N-0033 Oslo (Norway)

2005-01-20

Hepatic and renal concentrations of the elements arsenic, cadmium, cobalt, copper, lead, manganese, mercury, molybdenum, selenium and zinc were determined in samples collected from four crocodiles from the Kafue River, Kafue National Park and five crocodiles from the Luangwa River, Luangwa National Park, Zambia. The concentrations of the essential elements were similar to those reported in other vertebrates. Arsenic and cadmium concentrations were low (medians below 0.05 {mu}g As/g and below 0.16 {mu}g Cd/g, wet wt.). Mercury and lead concentrations were several orders of magnitude higher (medians up to 3.7 {mu}g Hg/g, and up to 8.7 {mu}g Pb/g, all wet wt.) than in hippopotami from the same rivers, probably as a result of food-chain biomagnification. Judging by the results obtained in this study, pollution from the mining activity around the Kafue River drainage area in the Copperbelt region has not significantly influenced the trace element concentrations in tissues of the crocodiles in the Kafue National Park. The trace element concentrations measured may serve as reference values in future studies on crocodilians.

ALTERED HISTOLOGY OF THE THYMUS AND SPLEEN IN CONTAMINANT-EXPOSED JUVENILE AMERICAN ALLIGATORS

Science.gov (United States)

Morphological difference in spleen and thymus are closely related to functional immune differences. Hormonal regulation of the immune system has been demonstrated in reptilian splenic and thymic tissue. Spleens and thymus were obtained from juvenile alligators at two reference si...

Long-term surgical anaesthesia with isoflurane in human habituated Nile Crocodiles

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George F. Stegmann

2017-02-01

Full Text Available A suitable long-term anaesthetic technique was required for implantation of physiological sensors and telemetric devices in sub-adult Nile crocodiles (Crocodylus niloticus to allow the collection of physiological data. Five Nile crocodiles with a median body mass of 24 kg were used. After manual capture, they were blindfolded and 0.2 mL (1 mg/mL medetomidine was administered intramuscularly in four of the animals which had an estimated body mass between 20 kg and 30 kg. One crocodile with an estimated body mass of 50 kg received 0.5 mL. For induction, 5 mL propofol (10 mg/mL was injected intravenously into the occipital sinus. Additional doses were given when required to ensure adequate anaesthesia. Anaesthesia was maintained with 1.5% isoflurane. Ventilation was controlled. Local anaesthesia was administered for surgical incision and external placement of the radio transmitter. Medetomidine was antagonised with atipamezole at the end of surgery. Median heart rate during surgery was 22 beats/min, at extubation 32 beats per min and 30 beats per min the following day at the same body temperature as under anaesthesia. Median body temperature of the animals increased from 27.3 °C to 27.9 °C during anaesthesia, as room temperature increased from 24.5 °C to 29.0 °C during surgery. Anaesthesia was successfully induced with intramuscular medetomidine and intravenous propofol and was maintained with isoflurane for the placement of telemetric implants. Intraoperative analgesia was supplemented with lidocaine infiltration. Perioperative physiological parameters remained stable and within acceptable clinical limits. Multiple factors appear to influence these variables during the recovery period, including residual anaesthetic effects, environmental temperature and physical activity.

A third case of amelia in Morelet's crocodile from the Yucatan Peninsula.

Science.gov (United States)

Charruau, Pierre; Niño-Torres, Carlos A

2014-07-03

Congenital defects in crocodilians have received little interest. In the context of global change and increasing threats to biodiversity, data on birth defects occurring in wildlife could be of importance for estimating the health of species populations and their ecosystems. Herein, we report the first case of amelia (i.e. absence of limbs) in Morelet's crocodiles Crocodylus moreletii from Mexico and the third on the southern Yucatan Peninsula. The crocodile in question was a juvenile (41 cm total length) captured in July 2012 in the Río Hondo, the river that forms the border between Mexico and Belize south of the state of Quintana Roo. The prevalence of this malformation in the C. moreletii population of Río Hondo (0.35%) is similar to that reported in 2 previous cases in Belize. Several causes of birth defects in crocodilians have previously been cited in the literature. Although we do not have relevant information to elucidate this case, we discuss some plausible explanations for this birth defect.

Alligator Rivers Analogue Project. Final Report - Volume 1

Energy Technology Data Exchange (ETDEWEB)

Duerden, P [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia); Lever, D A [AEA Technology, Harwell (United Kingdom); Sverjensky, D A [Johns Hopkins Univ., Baltimore, MD (United States); Townley, L R [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Wembley, WA (Australia). Div. of Water Resources

1992-07-01

This summary report, which highlights the work and findings of the Alligator Rivers Analogue Project (ARAP) is one of a series of 16 volumes, listed below. Detailed descriptions and results are provided in Volumes 2 to 16. Full acknowledgment to individual contributions is provided in the individual reports, and in Appendix I of this report. The findings from the technical studies are discussed in the context of assessments of the long-term performance of geological repositories for radioactive wastes, which are being undertaken in many countries. They are also considered in an integrated 'Scenario Development' approach, aimed to understand the formation of the ore deposit. Despite their inherent uncertainties, the findings provide a basis for assessing the way in which radionuclides will migrate in environments with a variety of geologic settings and over a range of different geologic timescales. Thus, section 2 of this report discusses the concept of using uranium deposits as natural analogues and refers to a number of such studies, including those at the Koongarra deposit in the Alligator Rivers Region of the Northern Territory of Australia. Section 3 reviews early scientific work in the Alligator Rivers Region and summarises the results of the analogue studies undertaken between 1981 and 1987 that were funded by the US Nuclear Regulatory Commission (USNRC) and the UK Department of the Environment (UKDoE). Section 4 describes the objectives of ARAP and the manner in which the study was conducted and provides a general outline of the project and a summary of the findings. A general description of the Koongarra ore deposit, the focus of ARAP, is provided in Section 5, with Sections 6-13 providing summaries of the work carried out to characterise the site in detail and provide data for modelling. Sections 14-18 discuss how this data was used in modelling and how the results may be applied for performance assessment studies. Finally, Section 19 considers the

Alligator Rivers Analogue Project. Final Report - Volume 1

International Nuclear Information System (INIS)

Duerden, P.; Lever, D.A.; Sverjensky, D.A.; Townley, L.R.

1992-01-01

This summary report, which highlights the work and findings of the Alligator Rivers Analogue Project (ARAP) is one of a series of 16 volumes, listed below. Detailed descriptions and results are provided in Volumes 2 to 16. Full acknowledgment to individual contributions is provided in the individual reports, and in Appendix I of this report. The findings from the technical studies are discussed in the context of assessments of the long-term performance of geological repositories for radioactive wastes, which are being undertaken in many countries. They are also considered in an integrated 'Scenario Development' approach, aimed to understand the formation of the ore deposit. Despite their inherent uncertainties, the findings provide a basis for assessing the way in which radionuclides will migrate in environments with a variety of geologic settings and over a range of different geologic timescales. Thus, section 2 of this report discusses the concept of using uranium deposits as natural analogues and refers to a number of such studies, including those at the Koongarra deposit in the Alligator Rivers Region of the Northern Territory of Australia. Section 3 reviews early scientific work in the Alligator Rivers Region and summarises the results of the analogue studies undertaken between 1981 and 1987 that were funded by the US Nuclear Regulatory Commission (USNRC) and the UK Department of the Environment (UKDoE). Section 4 describes the objectives of ARAP and the manner in which the study was conducted and provides a general outline of the project and a summary of the findings. A general description of the Koongarra ore deposit, the focus of ARAP, is provided in Section 5, with Sections 6-13 providing summaries of the work carried out to characterise the site in detail and provide data for modelling. Sections 14-18 discuss how this data was used in modelling and how the results may be applied for performance assessment studies. Finally, Section 19 considers the

Alligator Rivers analogue project

International Nuclear Information System (INIS)

Duerden, P.

1990-01-01

Australian Nuclear Science and Technology Organization has extensively evaluated uranium ore bodies in the Alligator Rivers Uranium Province in Australia as analogues of radioactive waste repositories. The work was extended for a three-year program as an international project based on the Koongarra uranium deposit and sponsored by the OECD Nuclear Energy Agency. The technical program comprises six major sub-projects involving modelling and experimental work: modelling of radionuclide migration; hydrogeology of the Koongarra uranium deposit; uranium/thorium series disequilibria studies; groundwater and colloid studies; fission product studies; transuranic nuclide studies; an outline of the technical programs and a summary of progress in the technical sub-projects is given. This is followed by a series of technical reports which briefly describe current research tasks, and which have been separately indexed

The influence of floodplain geomorphology and hydrologic connectivity on alligator gar (Atractosteus spatula) habitat along the embanked floodplain of the Lower Mississippi River

Science.gov (United States)

van der Most, Merel; Hudson, Paul F.

2018-02-01

The floodplain geomorphology of large lowland rivers is intricately related to aquatic ecosystems dependent upon flood pulse dynamics. The alligator gar (Atractosteus spatula) is native to the Lower Mississippi River and dependent upon floodplain backwater areas for spawning. In this study we utilize a geospatial approach to develop a habitat suitability index for alligator gar that explicitly considers hydrologic connectivity and the floodplain geomorphology along a frequently inundated segment of the Lower Mississippi River. The data sets include Landsat imagery, a high-resolution LiDAR digital elevation model (DEM), National Hydrography Dataset (NHD), and hydrologic and geomorphic data. A habitat suitability index is created based on the extent and frequency of inundation, water depth, temperature, and vegetation. A comparison between the remote sensing approach and the NHD revealed substantial differences in the area and location of water bodies available for alligator gar spawning. The final habitat suitability index indicates that a modest proportion (19%) of the overall embanked floodplain is available for alligator gar spawning. Opportunities exist for management efforts to utilize engineered and natural geomorphic features to facilitate hydrologic connectivity at flow levels below flood stage that would expand the habitat of alligator gar across the floodplain. The study results have direct implications regarding environmental restoration of the Lower Mississippi, an iconic example of an embanked meandering river floodplain.

Organochlorine pesticides and thiamine in eggs of largemouth bass and American alligators and their relationship with early life-stage mortality.

Science.gov (United States)

Sepúlveda, Maria S; Wiebe, Jon J; Honeyfield, Dale C; Rauschenberger, Heath R; Hinterkopf, Joy P; Johnson, William E; Gross, Timothy S

2004-10-01

Thiamine deficiency has been linked to early mortality syndrome in salmonids in the Great Lakes. This study was conducted to compare thiamine concentrations in American alligators (Alligator mississippiensis) and Florida largemouth bass (Micropterus salmoides floridanus) eggs from sites with high embryo mortality and high exposure to organochlorine pesticides (OCPs) (Lakes Apopka and Griffin, and Emeralda Marsh, Florida, USA) to those from sites that have historically exhibited low embryo mortality and low OCPs (Lakes Woodruff and Orange, Florida). During June-July 2000, 20 alligator clutches were collected from these sites, artificially incubated, and monitored for embryo mortality. Thiamine and OCPs were measured in one egg/clutch. During February 2002, 10 adult female bass were collected from Emeralda Marsh and Lake Woodruff and mature ovaries analyzed for thiamine and OCP concentrations. Although ovaries from the Emeralda Marsh bass contained almost 1,000-fold more OCPs compared with the reference site, Lake Woodruff, there were no differences in thiamine concentrations between sites (11,710 vs. 11,857 pmol/g). In contrast, alligator eggs from the reference site had five times the amount of thiamine compared with the contaminated sites (3,123 vs. 617 pmol/g). Similarly, clutches with >55% hatch rates had significantly higher concentrations of thiamine compared with clutches with reproductive failure and recruitment of largemouth bass. The cause(s) of this thiamine deficiency are unknown but might be related to differences in the nutritional value of prey items across the sites studied and/or to the presence of high concentration of contaminants in eggs.

The first fossil skull of Alligator sinensis from the Pleistocene, Taiwan, with a paleogeographic implication of the species

Science.gov (United States)

Hsi-yin, Shan; Yen-nien, Cheng; Xiao-chun, Wu

2013-06-01

A nearly complete fossil skull of Alligatoridae from the Pleistocene, Penghu Channel, east of Taiwan, is reported. It can be referred to the most latest clade of Alligatorinae, which includes Alligator sinensis, Alligator mississippiensis and Alligator mefferdi, on the basis of the following features: the splenial is excluded from the mandibular symphysis; the anterior tip of the splenial passes dorsal to the Meckelian groove; and the mandible is gently curved between the fourth alveoli and the mid dentary. It differs from A. mississippiensis and A. mefferdi mainly in the following characters: the breadth between the supratemporal fenestrae is approximately equal to the interorbital width, the snout is about half the length of the skull; and the anterior part of the snout is subtriangular in dorsal view. These features suggest that the Penghu alligator is most probably referable to A. sinensis. This is the only fossil skull of A. sinensis known. The discovery of the skull in Penghu Channel not only provides the first solid fossil evidence to indicate that the geological distribution of A. sinensis extended farther southeast than the historical/archeological range of the species but also adds new information on the biodiversity of the Penghu fauna.

Water Hyacinths and Alligator Weeds for Final Filtration of Sewage

Science.gov (United States)

Wolverton, B. C.; Mcdonald, R. C.; Gordon, J.

1976-01-01

The potential of water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxerides) (Mart.) Griesb. as secondary and tertiary filtration systems for domestic sewage was demonstrated. These two vascular aquatic plants reduced the suspended solids, total Kjeldahl nitrogen, total phosphorus, BOD sub 5, and total organic carbon levels in domestic sewage from 60 percent to 98 percent within a two week period. These plants grown in domestic sewage were also free of toxic levels of trace heavy metals.

First record of the invasive Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868 in the Crocodile River, Kruger National Park, South Africa

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Robin M. Petersen

2017-03-01

Full Text Available The redclaw crayfish Cherax quadricarinatus (von Martens, 1868, a robust freshwater crayfish native to Australia and Papua New Guinea, has now been recorded from the Kruger National Park (KNP. Previously absent from the Crocodile River, SAN Parks received a report in February 2016 of redclaw crayfish below the Van Graan Dam on the border of the KNP. Here, we provide evidence of the presence of redclaw crayfish in the Crocodile River. A better understanding of the redclaw crayfish distribution, habitat preferences, rate of spread and impacts on the local aquatic ecosystems in the Crocodile River is urgently required to develop mitigation strategies that minimise the spread of this invasive crayfish in the KNP and the Komati Catchment. The negative impacts of global crayfish introductions justify efforts to discourage further introductions and prevent their secondary spread. Conservation implications: A better understanding of the redclaw crayfish distribution, habitat preferences, rate of spread and impacts on the local aquatic ecosystems in the Crocodile River is urgently required to develop mitigation strategies that minimise the spread of this invasive crayfish in the Kruger National Park and the Komati Catchment.

Variation in Nest Temperatures of the American Alligator Found on the Kennedy Space Center Merritt Island National Wildlife Refuge

Science.gov (United States)

Lowers, Russell; Guillette, Louis J.; Weiss, Stephanie

2016-01-01

Information on nest temperatures of the American Alligator (Alligator mississippiensis) constructed in the wild is limited. Nesting temperatures during a critical thermal sensitive period determine the sex of alligators and are therefore critical in establishing the sex biases in recruitment efforts of alligators within a given community. Nest components, varying environmental conditions, and global warming could have a significant impact on nest temperatures, thus affecting future generations of a given population. One hundred and seventy four programmable thermistors were inserted into fifty eight nests from 2010 through 2015 nesting cycles. Three thermistors were placed inside each nest cavity (one on top of the eggs, one in the middle of the eggs, and one at the bottom of the clutch of the eggs) to collect temperature profiles in the incubation chamber and throughout the entire incubation period. One thermistor was also placed near or above these nests to obtain an ambient air temperature profile. Once retrieved, data from these thermistors were downloaded to examine temperature profiles throughout the incubation period as well as during the period of sexual determination. These data would help establish survival rates related to nest temperature and predict sex ratio of recruited neonates at the Kennedy Space Center. Over three million temperatures have been recorded since 2010 for the alligator thermistor study giving us insight to the recruitment efforts found here. Precipitation was the largest influence on nesting temperatures outside of daily photoperiod, with immediate changes of up to eight degrees Celsius.

Population genetics implications for the conservation of the Philippine Crocodile Crocodylus mindorensis Schmidt, 1935 (Crocodylia: Crocodylidae

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M.R.P. Hinlo

2014-03-01

Full Text Available Limited information is available on the Philippine Crocodile, Crocodylus mindorensis, concerning levels of genetic diversity either relative to other crocodilian species or among populations of the species itself. With only two known extant populations of C. mindorensis remaining, potentially low levels of genetic diversity are a conservation concern. Here, we evaluated 619 putative Philippine Crocodiles using a suite of 11 microsatellite markers, and compared them to four other crocodilian species sample sets. The two remaining populations from the island of Luzon and the island of Mindanao, representing the extremes of the former species’ distribution, appear to be differentiated as a result of genetic drift rather than selection. Both extant populations demonstrate lower genetic diversity and effective population sizes relative to other studied crocodilian species. The 57 C. mindorensis and C. porosus, Saltwater Crocodile, hybrids identified earlier from the Palawan Wildlife Rescue and Conservation Center were revalidated with a suite of 20 microsatellite loci; however, the timing of the event and the prevalence of hybridization in the species had yet to be fully determined. We defined the hybrids as one first cross from a C. porosus female and a C. mindorensis male and 56 C. mindorensis backcross individuals. This hybridization event appears to be confined to the PWRCC collection.

High genetic diversity and demographic history of captive Siamese and Saltwater crocodiles suggest the first step toward the establishment of a breeding and reintroduction program in Thailand.

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Sorravis Lapbenjakul

Full Text Available The Siamese crocodile (Crocodylus siamensis and Saltwater crocodile (C. porosus are two of the most endangered animals in Thailand. Their numbers have been reduced severely by hunting and habitat fragmentation. A reintroduction plan involving captive-bred populations that are used commercially is important and necessary as a conservation strategy to aid in the recovery of wild populations. Here, the genetic diversity and population structure of 69 individual crocodiles, mostly members of captive populations, were analyzed using both mitochondrial D-loop DNA and microsatellite markers. The overall haplotype diversity was 0.924-0.971 and the mean expected heterozygosity across 22 microsatellite loci was 0.578-0.701 for the two species. This agreed with the star-like shaped topology of the haplotype network, which suggests a high level of genetic diversity. The mean ratio of the number of alleles to the allelic range (M ratio for the populations of both species was considerably lower than the threshold of 0.68, which was interpreted as indicative of a historical genetic bottleneck. Microsatellite markers provided evidence of introgression for three individual crocodiles, which suggest that hybridization might have occurred between C. siamensis and C. porosus. D-loop sequence analysis detected bi-directional hybridization between male and female individuals of the parent species. Therefore, identification of genetically non-hybrid and hybrid individuals is important for long-term conservation management. Relatedness values were low within the captive populations, which supported their genetic integrity and the viability of a breeding and reintroduction management plan. This work constitutes the first step in establishing an appropriate source population from a scientifically managed perspective for an in situ/ex situ conservation program and reintroduction of crocodile individuals to the wild in Thailand.

Continuous Infraclavicular Block for Forearm Amputation After Being Bitten by a Saltwater Crocodile (Crocodylus Porosus: A Case Report

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Chin-Hsi Chiu

2009-08-01

Full Text Available Two important issues after a complete right forearm amputation are replantation and ongoing pain management. There are no reports of successful forearm replantation as a consequence of a crocodile bite. Here, we discuss our pain management in a case of complete forearm amputation after a bite from a saltwater crocodile (Crocodylus porosus, which necessitated six further operations to achieve successful replantation. Continuous infraclavicular brachial plexus block was effective for acute pain control in this case. We strongly recommend performing the block with an indwelling catheter under ultrasound guidance for higher accuracy and safety.

Carbon dioxide transport in alligator blood and its erythrocyte permeability to anions and water

DEFF Research Database (Denmark)

Jensen, F B; Wang, T; Jones, D R

1998-01-01

Deoxygenation of alligator red blood cells (RBCs) caused binding of two HCO3- equivalents per hemoglobin (Hb) tetramer at physiological pH. At lowered pH, some HCO3- binding also occurred to oxygenated Hb. The erythrocytic total CO2 content was large, and Hb-bound HCO3-, free HCO3-, and carbamate...

Spatial Ecology of the American Crocodile in a Tropical Pacific Island in Central America.

Science.gov (United States)

Balaguera-Reina, Sergio A; Venegas-Anaya, Miryam; Sánchez, Andrés; Arbelaez, Italo; Lessios, Harilaos A; Densmore, Llewellyn D

2016-01-01

Conservation of large predators has long been a challenge for biologists due to the limited information we have about their ecology, generally low numbers in the wild, large home ranges and the continuous expansion of human settlements. The American crocodile (Crocodylus acutus) is a typical apex predator, that has suffered from all of these characteristic problems, especially the latter one. Humans have had a major impact on the recovery of this species throughout its range, even though most of the countries it inhabits have banned hunting. The last decade has made it clear that in order to implement sound conservation and management programs, we must increase our understanding of crocodile spatial ecology. However, in only two countries where American crocodiles have telemetry studies even been published. Herein we have characterized the spatial ecology of C. acutus on Coiba Island, Panama, by radio-tracking (VHF transmitters) 24 individuals between 2010 and 2013, to determine movement patterns, home range, and habitat use. We have then compared our findings with those of previous studies to develop the most comprehensive assessment of American crocodile spatial ecology to date. Females showed a higher average movement distance (AMD) than males; similarly, adults showed a higher AMD than sub-adults and juveniles. However, males exhibited larger home ranges than females, and concomitantly sub-adults had larger home ranges than juveniles, hatchlings, and adults. There was an obvious relationship between seasonal precipitation and AMD, with increased AMD in the dry and "low-wet" seasons, and reduced AMD during the "true" wet season. We found disaggregate distributions according to age groups throughout the 9 habitat types in the study area; adults and hatchlings inhabited fewer habitat types than juveniles and sub-adults. These sex- and age-group discrepancies in movement and habitat choice are likely due to the influences of reproductive biology and Coiba

Supervising Scientist for the Alligator Rivers Region Annual Report 1996-1997

International Nuclear Information System (INIS)

1997-01-01

One of the most significant developments during the year was the submission by Energy Resources of Australia Ltd of its Environmental Impact Statement for Jabiluka. The proposal is significantly different in technical detail from the Ranger and Nabarlek mines owing to the proposal to mine underground. Evaluation of the Environmental Performance of the uranium mines of the Alligator Rivers Region continued, with twice-yearly Environmental Performance Reviews (EPR) of Ranger and Nabarlek, and results reported to the Alligator Rivers Region Advisory Committee (ARRAC). Ongoing technical consultations took place through meetings of the Ranger Minesite Technical Committee. Issues relating to water disposal were addressed through the Ranger Water Management Working Group. Submissions were made regarding the Jabiluka Environmental Impact Assessment process and technical advice was provided to the Environmental Assessment Branch of Environment Australia during the assessment. The organisation's research program has reflected strategic directions set last year by the Alligator Rivers Region Technical Committee (ARRTC) concerning environmental impacts of mining. Key projects assess radiation exposure by members of the public as a result of uranium mining, the effectiveness of artificial wetlands in the treatment of mine waters, and the development of methods to assess the effectiveness of options for rehabilitation. Development of the research program into wetlands protection and management continued, including establishment of a coordinated monitoring program to measure and assess coastal change as a benchmark for monitoring effects of climate change in the Alligator Rivers Region (a key part of a national network). Other research activities included water quality research for the National River Health Program and revision of the National Water Quality Management Strategy, Water Quality Guidelines for Fresh and Marine Waters and conclusion of research projects in the Mount

Evidence for Wild Crocodiles as a Risk for Human Leptospirosis, Mexico.

Science.gov (United States)

Pérez-Flores, Jonathan; Charruau, Pierre; Cedeño-Vázquez, Rogelio; Atilano, Daniel

2017-03-01

Sentinel species such as crocodilians are used to monitor the health of ecosystems. However, few studies have documented the presence of zoonotic diseases in wild populations of these reptiles. Herein we analyzed 48 serum samples from Crocodylus acutus (n = 34) and C. moreletii (n = 14) from different sites in the state of Quintana Roo (Mexico) to detect antibodies to Leptospira interrogans by means of a microscopic agglutination test (MAT). Crocodylus acutus and C. moreletii tested positive to 11 and 9 serovars, respectively, with Grippotyphosa being the serovar with the highest prevalence in Cozumel island (100%), Banco Chinchorro Biosphere Reserve (70.6%), and Río Hondo (100%), while in Chichankanab Lake, it was Bratislava (75%). Titers ranged from 1:50 to 1:3200, and the most frequent was 1:50 in all study sites. Leptospira is present in fresh and saltwater individuals due to the resistance of the bacterium in both environments. Cases of infected people involved with crocodile handling and egg collection suggest that these reptiles could play an important role in the transmission of leptospirosis. Preventive medicine programs should consider the monitoring of reptiles, and testing the soil and water, to prevent outbreaks of leptospirosis in facilities containing crocodiles.

Sequencing, de novo assembling, and annotating the genome of the endangered Chinese crocodile lizard Shinisaurus crocodilurus.

Science.gov (United States)

Gao, Jian; Li, Qiye; Wang, Zongji; Zhou, Yang; Martelli, Paolo; Li, Fang; Xiong, Zijun; Wang, Jian; Yang, Huanming; Zhang, Guojie

2017-07-01

The Chinese crocodile lizard, Shinisaurus crocodilurus, is the only living representative of the monotypic family Shinisauridae under the order Squamata. It is an obligate semi-aquatic, viviparous, diurnal species restricted to specific portions of mountainous locations in southwestern China and northeastern Vietnam. However, in the past several decades, this species has undergone a rapid decrease in population size due to illegal poaching and habitat disruption, making this unique reptile species endangered and listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora Appendix II since 1990. A proposal to uplist it to Appendix I was passed at the Convention on International Trade in Endangered Species of Wild Fauna and Flora Seventeenth meeting of the Conference of the Parties in 2016. To promote the conservation of this species, we sequenced the genome of a male Chinese crocodile lizard using a whole-genome shotgun strategy on the Illumina HiSeq 2000 platform. In total, we generated ∼291 Gb of raw sequencing data (×149 depth) from 13 libraries with insert sizes ranging from 250 bp to 40 kb. After filtering for polymerase chain reaction-duplicated and low-quality reads, ∼137 Gb of clean data (×70 depth) were obtained for genome assembly. We yielded a draft genome assembly with a total length of 2.24 Gb and an N50 scaffold size of 1.47 Mb. The assembled genome was predicted to contain 20 150 protein-coding genes and up to 1114 Mb (49.6%) of repetitive elements. The genomic resource of the Chinese crocodile lizard will contribute to deciphering the biology of this organism and provides an essential tool for conservation efforts. It also provides a valuable resource for future study of squamate evolution. © The Authors 2017. Published by Oxford University Press.

A Comprehensive Analysis of the Phylogeny, Genomic Organization and Expression of Immunoglobulin Light Chain Genes in Alligator sinensis, an Endangered Reptile Species.

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Xifeng Wang

Full Text Available Crocodilians are evolutionarily distinct reptiles that are distantly related to lizards and are thought to be the closest relatives of birds. Compared with birds and mammals, few studies have investigated the Ig light chain of crocodilians. Here, employing an Alligator sinensis genomic bacterial artificial chromosome (BAC library and available genome data, we characterized the genomic organization of the Alligator sinensis IgL gene loci. The Alligator sinensis has two IgL isotypes, λ and κ, the same as Anolis carolinensis. The Igλ locus contains 6 Cλ genes, each preceded by a Jλ gene, and 86 potentially functional Vλ genes upstream of (Jλ-Cλn. The Igκ locus contains a single Cκ gene, 6 Jκs and 62 functional Vκs. All VL genes are classified into a total of 31 families: 19 Vλ families and 12 Vκ families. Based on an analysis of the chromosomal location of the light chain genes among mammals, birds, lizards and frogs, the data further confirm that there are two IgL isotypes in the Alligator sinensis: Igλ and Igκ. By analyzing the cloned Igλ/κ cDNA, we identified a biased usage pattern of V families in the expressed Vλ and Vκ. An analysis of the junctions of the recombined VJ revealed the presence of N and P nucleotides in both expressed λ and κ sequences. Phylogenetic analysis of the V genes revealed V families shared by mammals, birds, reptiles and Xenopus, suggesting that these conserved V families are orthologous and have been retained during the evolution of IgL. Our data suggest that the Alligator sinensis IgL gene repertoire is highly diverse and complex and provide insight into immunoglobulin gene evolution in vertebrates.

A Comprehensive Analysis of the Phylogeny, Genomic Organization and Expression of Immunoglobulin Light Chain Genes in Alligator sinensis, an Endangered Reptile Species

Science.gov (United States)

Lu, Yan; Zhang, Chenglin; Wu, Xiaobing; Han, Haitang; Zhao, Yaofeng; Ren, Liming

2016-01-01

Crocodilians are evolutionarily distinct reptiles that are distantly related to lizards and are thought to be the closest relatives of birds. Compared with birds and mammals, few studies have investigated the Ig light chain of crocodilians. Here, employing an Alligator sinensis genomic bacterial artificial chromosome (BAC) library and available genome data, we characterized the genomic organization of the Alligator sinensis IgL gene loci. The Alligator sinensis has two IgL isotypes, λ and κ, the same as Anolis carolinensis. The Igλ locus contains 6 Cλ genes, each preceded by a Jλ gene, and 86 potentially functional Vλ genes upstream of (Jλ-Cλ)n. The Igκ locus contains a single Cκ gene, 6 Jκs and 62 functional Vκs. All VL genes are classified into a total of 31 families: 19 Vλ families and 12 Vκ families. Based on an analysis of the chromosomal location of the light chain genes among mammals, birds, lizards and frogs, the data further confirm that there are two IgL isotypes in the Alligator sinensis: Igλ and Igκ. By analyzing the cloned Igλ/κ cDNA, we identified a biased usage pattern of V families in the expressed Vλ and Vκ. An analysis of the junctions of the recombined VJ revealed the presence of N and P nucleotides in both expressed λ and κ sequences. Phylogenetic analysis of the V genes revealed V families shared by mammals, birds, reptiles and Xenopus, suggesting that these conserved V families are orthologous and have been retained during the evolution of IgL. Our data suggest that the Alligator sinensis IgL gene repertoire is highly diverse and complex and provide insight into immunoglobulin gene evolution in vertebrates. PMID:26901135

Blow Flies Visiting Decaying Alligators: Is Succession Synchronous or Asynchronous?

OpenAIRE

Nelder, Mark P.; McCreadie, John W.; Major, Clinton S.

2009-01-01

Succession patterns of adult blow flies (Diptera: Calliphoridae) on decaying alligators were investigated in Mobile (Ala, USA) during August 2002. The most abundant blow fly species visiting the carcasses were Chrysomya rufifacies (Macquart), Cochliomyia macellaria (Fabricus), Chrysomya megacephala (Fabricus), Phormia regina (Meigen), and Lucilia coeruleiviridis (Macquart). Lucilia coeruleiviridis was collected more often during the early stages of decomposition, followed by Chrysomya spp., C...

Thermal fluctuation within nests and predicted sex ratio of Morelet's Crocodile.

Science.gov (United States)

Escobedo-Galván, Armando H; López-Luna, Marco A; Cupul-Magaña, Fabio G

2016-05-01

Understanding the interplay between thermal variations and sex ratio in reptiles with temperature-dependent sex determination is the first step for developing long-term conservation strategies. In case of crocodilians, the information is fragmentary and insufficient for establishing a general framework to consider how thermal fluctuation influence sex determination under natural conditions. The main goal of this study was to analyze thermal variation in nests of Crocodylus moreletii and to discuss the potential implications for predicting offspring sex ratio. The study was carried out at the Centro de Estudios Tecnológicos del Mar N° 2 and at the Sistemas Productivos Cocodrilo, Campeche, Mexico. Data was collected in the nesting season of Morelet's Crocodiles during three consecutive seasons (2007-2009). Thermal fluctuations for multiple areas of the nest chamber were registered by data loggers. We calculate the constant temperature equivalent based on thermal profiles among nests to assess whether there are differences between the nest temperature and its equivalent to constant temperature. We observed that mean nest temperature was only different among nests, while daily thermal fluctuations vary depending on the depth position within the nest chamber, years and nests. The constant temperature equivalent was different among and within nests, but not among survey years. We observed differences between constant temperature equivalent and mean nest temperature both at the top and in the middle of the nest cavities, but were not significantly different at the bottom of nest cavities. Our results enable examine and discuss the relevance of daily thermal fluctuations to predict sex ratio of the Morelet's Crocodile. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hydrodynamic analysis, performance assessment, and actuator design of a flexible tail propulsor in an artificial alligator

International Nuclear Information System (INIS)

Philen, Michael; Neu, Wayne

2011-01-01

The overall objective of this research is to develop analysis tools for determining actuator requirements and assessing viable actuator technology for design of a flexible tail propulsor in an artificial alligator. A simple hydrodynamic model that includes both reactive and resistive forces along the tail is proposed and the calculated mean thrust agrees well with conventional estimates of drag. Using the hydrodynamic model forces as an input, studies are performed for an alligator ranging in size from 1 cm to 2 m at swimming speeds of 0.3–1.8 body lengths per second containing five antagonistic pairs of actuators distributed along the length of the tail. Several smart materials are considered for the actuation system, and preliminary analysis results indicate that the acrylic electroactive polymer and the flexible matrix composite actuators are potential artificial muscle technologies for the system

Dietary pathways through lizards of the Alligator Rivers Region

International Nuclear Information System (INIS)

James, C.D.; Morton, S.R.; Braithwaite, R.W.; Wombey, J.C.

1984-07-01

A broad survey of the diets of 46 species of terrestrial and arboreal lizards from the families Gekkonidae, Pygopodidae, Agamidae and Scincidae was carried out in the Alligator Rivers Region, and the diets of three of the species were examined in detail by monthly sampling near the Ranger uranium mine. The study shows that, in the event of contamination of the waterbodies, only two species of lizards face any risk of contamination through their food

Plants of the Alligator Rivers Region, Northern Territory

International Nuclear Information System (INIS)

Cowie, I.D.; Finlayson, C.M.

1986-01-01

Published and unpublished lists of plants of the Alligator Rivers Region have been combined into a single, up-to-date check-list. The list has been designed to replace fragmented, regional listings with a single document suitable for use by both professional and amateur botanists. The list is ordered in the taxonomic sequence adopted for the Flora of Australia and includes 1346 species from 165 families. These are 1275 native and 71 alien species listed. Separate lists of rare species are given and discussed

Plants of the Alligator Rivers Region, Northern Territory

Energy Technology Data Exchange (ETDEWEB)

Cowie, I D; Finlayson, C M

1986-01-01

Published and unpublished lists of plants of the Alligator Rivers Region have been combined into a single, up-to-date check-list. The list has been designed to replace fragmented, regional listings with a single document suitable for use by both professional and amateur botanists. The list is ordered in the taxonomic sequence adopted for the Flora of Australia and includes 1346 species from 165 families. These are 1275 native and 71 alien species listed. Separate lists of rare species are given and discussed.

Alligator rivers analogue project. Final report; volume 1; summary of findings

International Nuclear Information System (INIS)

Duerden, P.; Lever, D.A.; Sverjensky, D.A.; Townley, L.R.

1992-01-01

The Koongarra uranium ore deposit is located in the Alligator Rivers Region of the Northern Territory of Australia. Many of the processes that have controlled the development of this natural system are relevant to the performance assessment of radioactive waste repositories. An agreement was reached in 1987 by a number of agencies concerned with radioactive waste disposal to set up the International Alligator Rivers Analogue Project (ARAP) to study relevant aspects of the hydrological and geochemical evolution of the site. The Project ran for five years. The aims of the study were: to contribute to the production of reliable and realistic models for radionuclide migration within geological environments relevant to the assessment of the safety of radioactive waste repositories; to develop methods of validation of models using a combination of laboratory and field data associated with the Koongarra uranium deposit; and to encourage maximum interaction between modellers and experimentalists in achieving these objectives. It was anticipated that the substantial databases generated in the field and laboratory studies would then be used to develop and test geochemical and radionuclide transport models. The findings from the technical studies are discussed in the context of assessments of the long-term performance of geological repositories for radioactive wastes, which are being undertaken in many countries. They are also considered in an integrated 'Scenario Development' approach, aimed to understand the formation of the ore deposit. Despite their inherent uncertainties, the findings provide a basis for assessing the way in which radionuclides will migrate in environments with a variety of geologic settings and over a range of different geologic timescales. This summary report, which highlights the work and findings of the Alligator Rivers Analogue Project is one of a series of 16 volumes

Dynamic Changes in Host Gene Expression following In Vitro Viral Mimic Stimulation in Crocodile Cells

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Subir Sarker

2017-11-01

Full Text Available The initial control of viral infection in a host is dominated by a very well orchestrated early innate immune system; however, very little is known about the ability of a host to control viral infection outside of mammals. The reptiles offer an evolutionary bridge between the fish and mammals, with the crocodile having evolved from the archosauria clade that included the dinosaurs, and being the largest living reptile species. Using an RNA-seq approach, we have defined the dynamic changes of a passaged primary crocodile cell line to stimulation with both RNA and DNA viral mimics. Cells displayed a marked upregulation of many genes known to be involved in the mammalian response to viral infection, including viperin, Mx1, IRF7, IRF1, and RIG-I with approximately 10% of the genes being uncharacterized transcripts. Both pathway and genome analysis suggested that the crocodile may utilize the main known mammalian TLR and cytosolic antiviral RNA signaling pathways, with the pathways being responsible for sensing DNA viruses less clear. Viral mimic stimulation upregulated the type I interferon, IFN-Omega, with many known antiviral interferon-stimulated genes also being upregulated. This work demonstrates for the first time that reptiles show functional regulation of many known and unknown antiviral pathways and effector genes. An enhanced knowledge of these ancient antiviral pathways will not only add to our understanding of the host antiviral innate response in non-mammalian species, but is critical to fully comprehend the complexity of the mammalian innate immune response to viral infection.

Trace element concentrations of wild saltwater crocodile eggs

International Nuclear Information System (INIS)

Manolis, S.C.; Webb, G.J.; Britton, A.R.; Jeffree, R.A.; Markich, S.J.

2002-01-01

Saltwater crocodiles (Crocodylus porosus) accumulate trace elements from the environment into their flesh and bones (Jeffree et al., 2001a). Elevated levels of metals (e.g. Hg, Zn, Pb), organochlorines (e.g. DDT) and radionuclides (e.g. radiocesium) have been recorded in blood, tissues and eggs of several crocodilian species (Manolis et al., this volume). In this study the concentrations of various elements (including metals) were measured in the yolk of C. porosus eggs collected from the Finniss River and two other distant nesting sites (Melacca Swamp, a spring-fed freshwater swamp; Adelaide River, a tidal river) during the 2000- 01 nesting season. Infertile eggs from 30 clutches (Adelaide 12, Melacca 8, Finniss 10) were opened and the yolk contents removed (after Webb et al., 1987) and frozen. Samples of yolk were then oven-dried, digested in nitric acid and hydrogen peroxide. The digest solutions were then analysed for 20 elements (see Table 1) using inductively coupled plasma mass spectroscopy. Similarities between the elemental composition of eggs from the three areas suggests that downstream contamination from Rum Jungle Mine is not apparent in C. porosus nesting in the Finniss River. These nesting areas are some 60 km downstream of the mine site, and contaminants are probably greatly diluted during the wet season. C. porosus were also intensively hunted in the Finniss River area during the 1950s and 1960s, until their protection in 1971 (Webb et al. 1984). Some females would have been recruited into the population after the period of mining. Long-term effects of the mine may be apparent in areas with Australian freshwater crocodiles (C. johnstoni), mainly upstream of C. porosus nesting areas and up to the mine. Examination of tissues and eggs of C. johnstoni may provide more information on the historical effects of the mine

alpha-Crystallin A sequences of Alligator mississippiensis and the lizard Tupinambis teguixin: molecular evolution and reptilian phylogeny.

Science.gov (United States)

de Jong, W W; Zweers, A; Versteeg, M; Dessauer, H C; Goodman, M

1985-11-01

The amino acid sequences of the eye lens protein alpha-crystallin A from many mammalian and avian species, two frog species, and a dogfish have provided detailed information about the molecular evolution of this protein and allowed some useful inferences about phylogenetic relationships among these species. We now have isolated and sequenced the alpha-crystallins of the American alligator and the common tegu lizard. The reptilian alpha A chains appear to have evolved as slowly as those of other vertebrates, i.e., at two to three amino acid replacements per 100 residues in 100 Myr. The lack of charged replacements and the general types and distribution of replacements also are similar to those in other vertebrate alpha A chains. Maximum-parsimony analyses of the total data set of 67 vertebrate alpha A sequences support the monophyletic origin of alligator, tegu, and birds and favor the grouping of crocodilians and birds as surviving sister groups in the subclass Archosauria.

A New Class of SINEs with snRNA Gene-Derived Heads.

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Kojima, Kenji K

2015-05-27

Eukaryotic genomes are colonized by various transposons including short interspersed elements (SINEs). The 5' region (head) of the majority of SINEs is derived from one of the three types of RNA genes--7SL RNA, transfer RNA (tRNA), or 5S ribosomal RNA (rRNA)--and the internal promoter inside the head promotes the transcription of the entire SINEs. Here I report a new group of SINEs whose heads originate from either the U1 or U2 small nuclear RNA gene. These SINEs, named SINEU, are distributed among crocodilians and classified into three families. The structures of the SINEU-1 subfamilies indicate the recurrent addition of a U1- or U2-derived sequence onto the 5' end of SINEU-1 elements. SINEU-1 and SINEU-3 are ancient and shared among alligators, crocodiles, and gharials, while SINEU-2 is absent in the alligator genome. SINEU-2 is the only SINE family that was active after the split of crocodiles and gharials. All SINEU families, especially SINEU-3, are preferentially inserted into a family of Mariner DNA transposon, Mariner-N4_AMi. A group of Tx1 non-long terminal repeat retrotransposons designated Tx1-Mar also show target preference for Mariner-N4_AMi, indicating that SINEU was mobilized by Tx1-Mar. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Phylogenomic analyses support the position of turtles as the sister group of birds and crocodiles (Archosauria)

Science.gov (United States)

2012-01-01

Background The morphological peculiarities of turtles have, for a long time, impeded their accurate placement in the phylogeny of amniotes. Molecular data used to address this major evolutionary question have so far been limited to a handful of markers and/or taxa. These studies have supported conflicting topologies, positioning turtles as either the sister group to all other reptiles, to lepidosaurs (tuatara, lizards and snakes), to archosaurs (birds and crocodiles), or to crocodilians. Genome-scale data have been shown to be useful in resolving other debated phylogenies, but no such adequate dataset is yet available for amniotes. Results In this study, we used next-generation sequencing to obtain seven new transcriptomes from the blood, liver, or jaws of four turtles, a caiman, a lizard, and a lungfish. We used a phylogenomic dataset based on 248 nuclear genes (187,026 nucleotide sites) for 16 vertebrate taxa to resolve the origins of turtles. Maximum likelihood and Bayesian concatenation analyses and species tree approaches performed under the most realistic models of the nucleotide and amino acid substitution processes unambiguously support turtles as a sister group to birds and crocodiles. The use of more simplistic models of nucleotide substitution for both concatenation and species tree reconstruction methods leads to the artefactual grouping of turtles and crocodiles, most likely because of substitution saturation at third codon positions. Relaxed molecular clock methods estimate the divergence between turtles and archosaurs around 255 million years ago. The most recent common ancestor of living turtles, corresponding to the split between Pleurodira and Cryptodira, is estimated to have occurred around 157 million years ago, in the Upper Jurassic period. This is a more recent estimate than previously reported, and questions the interpretation of controversial Lower Jurassic fossils as being part of the extant turtles radiation. Conclusions These results

Phylogenomic analyses support the position of turtles as the sister group of birds and crocodiles (Archosauria

Directory of Open Access Journals (Sweden)

Chiari Ylenia

2012-07-01

Full Text Available Abstract Background The morphological peculiarities of turtles have, for a long time, impeded their accurate placement in the phylogeny of amniotes. Molecular data used to address this major evolutionary question have so far been limited to a handful of markers and/or taxa. These studies have supported conflicting topologies, positioning turtles as either the sister group to all other reptiles, to lepidosaurs (tuatara, lizards and snakes, to archosaurs (birds and crocodiles, or to crocodilians. Genome-scale data have been shown to be useful in resolving other debated phylogenies, but no such adequate dataset is yet available for amniotes. Results In this study, we used next-generation sequencing to obtain seven new transcriptomes from the blood, liver, or jaws of four turtles, a caiman, a lizard, and a lungfish. We used a phylogenomic dataset based on 248 nuclear genes (187,026 nucleotide sites for 16 vertebrate taxa to resolve the origins of turtles. Maximum likelihood and Bayesian concatenation analyses and species tree approaches performed under the most realistic models of the nucleotide and amino acid substitution processes unambiguously support turtles as a sister group to birds and crocodiles. The use of more simplistic models of nucleotide substitution for both concatenation and species tree reconstruction methods leads to the artefactual grouping of turtles and crocodiles, most likely because of substitution saturation at third codon positions. Relaxed molecular clock methods estimate the divergence between turtles and archosaurs around 255 million years ago. The most recent common ancestor of living turtles, corresponding to the split between Pleurodira and Cryptodira, is estimated to have occurred around 157 million years ago, in the Upper Jurassic period. This is a more recent estimate than previously reported, and questions the interpretation of controversial Lower Jurassic fossils as being part of the extant turtles radiation

Post-hatching development of mitochondrial function, organ mass and metabolic rate in two ectotherms, the American alligator (Alligator mississippiensis and the common snapping turtle (Chelydra serpentina

Directory of Open Access Journals (Sweden)

Sarah K. G. Sirsat

2016-04-01

Full Text Available The ontogeny of endothermy in birds is associated with disproportionate growth of thermogenic organs and increased mitochondrial oxidative capacity. However, no similar study has been made of the development of these traits in ectotherms. For comparison, we therefore investigated the metabolism, growth and muscle mitochondrial function in hatchlings of a turtle and a crocodilian, two ectotherms that never develop endothermy. Metabolic rate did not increase substantially in either species by 30 days post-hatching. Yolk-free body mass and heart mass did not change through 30 days in alligators and heart mass was a constant proportion of body mass, even after 1 year. Yolk-free body mass and liver mass grew 36% and 27%, respectively, in turtles during the first 30 days post-hatch. The mass-specific oxidative phosphorylation capacity of mitochondria, assessed using permeabilized muscle fibers, increased by a non-significant 47% in alligator thigh and a non-significant 50% in turtle thigh over 30 days, but did not increase in the heart. This developmental trajectory of mitochondrial function is slower and shallower than that previously observed in ducks, which demonstrate a 90% increase in mass-specific oxidative phosphorylation capacity in thigh muscles over just a few days, a 60% increase in mass-specific oxidative phosphorylation capacity of the heart over a few days, and disproportionate growth of the heart and other organs. Our data thus support the hypothesis that these developmental changes in ducks represent mechanistic drivers for attaining endothermy.

Post-hatching development of mitochondrial function, organ mass and metabolic rate in two ectotherms, the American alligator (Alligator mississippiensis) and the common snapping turtle (Chelydra serpentina).

Science.gov (United States)

Sirsat, Sarah K G; Sirsat, Tushar S; Price, Edwin R; Dzialowski, Edward M

2016-04-15

The ontogeny of endothermy in birds is associated with disproportionate growth of thermogenic organs and increased mitochondrial oxidative capacity. However, no similar study has been made of the development of these traits in ectotherms. For comparison, we therefore investigated the metabolism, growth and muscle mitochondrial function in hatchlings of a turtle and a crocodilian, two ectotherms that never develop endothermy. Metabolic rate did not increase substantially in either species by 30 days post-hatching. Yolk-free body mass and heart mass did not change through 30 days in alligators and heart mass was a constant proportion of body mass, even after 1 year. Yolk-free body mass and liver mass grew 36% and 27%, respectively, in turtles during the first 30 days post-hatch. The mass-specific oxidative phosphorylation capacity of mitochondria, assessed using permeabilized muscle fibers, increased by a non-significant 47% in alligator thigh and a non-significant 50% in turtle thigh over 30 days, but did not increase in the heart. This developmental trajectory of mitochondrial function is slower and shallower than that previously observed in ducks, which demonstrate a 90% increase in mass-specific oxidative phosphorylation capacity in thigh muscles over just a few days, a 60% increase in mass-specific oxidative phosphorylation capacity of the heart over a few days, and disproportionate growth of the heart and other organs. Our data thus support the hypothesis that these developmental changes in ducks represent mechanistic drivers for attaining endothermy. © 2016. Published by The Company of Biologists Ltd.

Maximal Aerobic and Anaerobic Power Generation in Large Crocodiles versus Mammals: Implications for Dinosaur Gigantothermy

OpenAIRE

Seymour, Roger S.

2013-01-01

Inertial homeothermy, the maintenance of a relatively constant body temperature that occurs simply because of large size, is often applied to large dinosaurs. Moreover, biophysical modelling and actual measurements show that large crocodiles can behaviourally achieve body temperatures above 30?C. Therefore it is possible that some dinosaurs could achieve high and stable body temperatures without the high energy cost of typical endotherms. However it is not known whether an ectothermic dinosau...

Demise of the Nile crocodile (Crocodylus niloticus) as a keystone species for aquatic ecosystem conservation in South Africa: the case of the Olifants River

CSIR Research Space (South Africa)

Ashton, PJ

2010-06-01

Full Text Available of the catchment (Middleton and Bailey, 2009). The upper reaches of the Olifants catchment (Figure 1) are characterized by large-scale coal mining, coal-fired power generation plants, irrigated agriculture and a diverse array of heavy and light industries... trade in crocodile products is subject to Appendix I of the CITES Convention (Groombridge, 1982). Prior to the promulgation of South African reptile protection legislation in 1969, Nile crocodiles were regarded as vermin, to be shot on sight (Pooley...

Evaluating the effect of salinity on a simulated American crocodile (Crocodylus acutus) population with applications to conservation and Everglades restoration

NARCIS (Netherlands)

Richards, P.M.; Mooij, W.M.; DeAngelis, D.L.

2004-01-01

Everglades restoration will alter the hydrology of South Florida, affecting both water depth and salinity levels in the southern fringes of the Everglades, the habitat of the endangered American crocodile (Crocodylus acutus). A key question is what the effects of these hydrologic changes will be on

The alligator woman's tale: remembering Nicaragua's "first self-declared lesbian".

Science.gov (United States)

González-Rivera, Victoria

2014-01-01

Carmen Aguirre (1931-1971) was a young woman who lived as a self-made man in the 1960s under the brutal, yet populist, right-wing Somoza dictatorship in Nicaragua. Carmen was known as Carmelo or la Caimana (the alligator woman). This article sheds light not only on la Caimana's life, but on how he is remembered today in Nicaragua. It addresses dynamics of Nicaragua's sexual past, present, and future, as well as theoretical questions dealing with identity, sex, and politics.

EFFECT OF ACUTE STRESS ON PLASMA CONCENTRATIONS OF SEX AND STRESS HORMONES IN JUVENILE ALLIGATORS LIVING IN CONTROL AND CONTAMINATED LAKES

Science.gov (United States)

Environmental contaminants can act as stressors, inducing elevated circulating concentrations of stress hormones such as corticosterone and cortisol. Development in contaminated eggs has been reported to modify circulating sex steroid hormone concentrations in alligators (Alligat...

Metals in the caudal scutes of Morelet's crocodile (Crocodylus moreletii) from the southern Gulf of Mexico.

Science.gov (United States)

Trillanes, C E; Pérez-Jiménez, J C; Rosíles-Martínez, R; González-Jáuregui, M

2014-10-01

Caudal scutes were collected from 92 Morelet's crocodiles (Crocodylus moreletii) between May and August 2012, in three Wildlife Management and Use Units (UMAs, from its name in Spanish) and three wild sites in Campeche, Mexico. The UMAs are intensive, with an ex situ approach to manage crocodiles in captivity. The concentrations of arsenic, mercury, lead, nickel, cadmium and chromium were analyzed in each sample. As and Pb were detected in all samples, Hg in 86 and Ni in 74. The metal concentrations estimated were higher than most of the concentrations reported for skin, tail tip and caudal scutes in other crocodilians around the world. The concentration of As, Pb and Ni was significantly greater in the free-ranging groups than in the captive groups in UMAs (p < 0.05). Negative linear relationship was estimated between the snout-vent length and the concentration of Pb (in five groups) and Ni (in three groups). In this region C. moreletii is exposed to metals contamination and more studies are necessary to establish if represents a risk to their populations.

Were human babies used as bait in crocodile hunts in colonial Sri Lanka?

Directory of Open Access Journals (Sweden)

Anslem de Silva

2015-01-01

Full Text Available Use of live animals as bait is not an uncommon practice in hunting worldwide.  However, some curious accounts of the use of human babies as bait to lure crocodiles in sport hunting exist on the island of Sri Lanka, where sport hunting was common during the British colonial period.  Herein we compile the available records, review other records of the practice, and discuss the likelihood of the exercise actually having taken place. 

Development of transient head cavities during early organogenesis of the Nile Crocodile (Crocodylus niloticus)

Czech Academy of Sciences Publication Activity Database

Kundrát, M.; Janáček, Jiří; Martin, S.

2009-01-01

Roč. 270, č. 9 (2009), s. 1069-1083 ISSN 0362-2525 R&D Projects: GA AV ČR(CZ) KJB6111301 Grant - others:Univerzita Karlova(CZ) 122/2003-B; NATO Fellowship Programme and Center for Higher Education Studies(CZ) MK2003-13 Institutional research plan: CEZ:AV0Z50110509 Keywords : Nile Crocodile * head cavities * organogenesis Subject RIV: EA - Cell Biology Impact factor: 1.706, year: 2009

Recovery rates, serotypes, and antimicrobial susceptibility patterns of Salmonellae isolated from cloacal swabs of wild Nile crocodiles (Crocodylus niloticus) in Zimbabwe

DEFF Research Database (Denmark)

Madsen, Mogens; Hangartner, P.; West, K.

1998-01-01

Samples from the cloaca and the ventral skin surface of 67 Nile crocodiles (Crocodylus niloticus) captured in four uninhabited areas at Lake Kariba, Zimbabwe, were cultured for Salmonella. All the skin samples tested negative for Salmonella, whereas 18 of 67 (26.9%) cloacal samples grew Salmonell...

Flexible Measurement of Bioluminescent Reporters Using an Automated Longitudinal Luciferase Imaging Gas- and Temperature-optimized Recorder (ALLIGATOR).

Science.gov (United States)

Crosby, Priya; Hoyle, Nathaniel P; O'Neill, John S

2017-12-13

Luciferase-based reporters of cellular gene expression are in widespread use for both longitudinal and end-point assays of biological activity. In circadian rhythms research, for example, clock gene fusions with firefly luciferase give rise to robust rhythms in cellular bioluminescence that persist over many days. Technical limitations associated with photomultiplier tubes (PMT) or conventional microscopy-based methods for bioluminescence quantification have typically demanded that cells and tissues be maintained under quite non-physiological conditions during recording, with a trade-off between sensitivity and throughput. Here, we report a refinement of prior methods that allows long-term bioluminescence imaging with high sensitivity and throughput which supports a broad range of culture conditions, including variable gas and humidity control, and that accepts many different tissue culture plates and dishes. This automated longitudinal luciferase imaging gas- and temperature-optimized recorder (ALLIGATOR) also allows the observation of spatial variations in luciferase expression across a cell monolayer or tissue, which cannot readily be observed by traditional methods. We highlight how the ALLIGATOR provides vastly increased flexibility for the detection of luciferase activity when compared with existing methods.

Surveys of tidal river systems in the northern territory of Australia and their crocodile populations

Energy Technology Data Exchange (ETDEWEB)

Vorlicek, G.C.; Messel, H.; Green, W.J.

1986-01-01

This book provides an update on the population dynamics of Crocodylus porous in the tidal waterways of Van Diemen Gulf and the Southern Gulf of Carpentaria, Australia, during 1984 and 1985. Contents: Prologue; Dedication; Introduction; Status of Crocodylus porous. July 1984, in the tidal waterways of the Alligator Region and in the Adelaide River System of Northern Australia: recovery underway; Resurvey of Crocodylus porous populations in the tidal waterways of the southern Gulf of Carpentaria, September - October 1985; Local knowledge - Northern Australia style.

Potential impact of Dare County landfills on Alligator River National Wildlife Refuge

Science.gov (United States)

Winger, P.V.; Lasier, P.J.; Augspurger, T.

2005-01-01

Runoff of leachate from East Lake and Dare County Construction and Demolition Debris landfills has the potential to impact wildlife resources at Alligator River National Wildlife Refuge, Dare and Hyde Counties, North Carolina. Sediment quality of samples collected in August 2000 at 14 locations down-gradient from the landfills was assessed by measuring metal and organic contaminants in the sediments, chronic toxicity of solid-phase sediment (28-d static-renewal exposures; survival and growth as test endpoints) and acute toxicity of sediment porewater (96-h static exposures) to Hyalella azteca (Crustacea: Amphipoda). In addition, contaminant bioaccumulation from 4 sediments was determined using 28-d exposures of Lumbriculus variegatus (freshwater oligochaete). Although survival was not impaired, length of H. azteca was significantly reduced in sediments from 5 locations. Pore water from 4 locations was acutely toxic to H. azteca. Metals and a few polycyclic aromatic hydrocarbons (PAHs) were bioaccumulated by L. variegatus from the sediments. Several metals and PAHs exceeded sediment quality guidelines, and metals in porewater from several sites exceeded water quality criteria for the protection of aquatic wildlife. Runoff of leachate from the landfills has reduced sediment quality and has the potential to adversely affect wildlife resources at Alligator River National Wildlife Refuge.

As-CATH1-6, novel cathelicidins with potent antimicrobial and immunomodulatory properties from Alligator sinensis, play pivotal roles in host antimicrobial immune responses.

Science.gov (United States)

Chen, Yan; Cai, Shasha; Qiao, Xue; Wu, Mali; Guo, Zhilai; Wang, Renping; Kuang, Yi-Qun; Yu, Haining; Wang, Yipeng

2017-08-10

Crocodilians are regarded as possessing a powerful immune system. However, the composition and action of the crocodilian immune system have remained unclear until now. Cathelicidins, the principal family of host defense peptides, play pivotal roles in vertebrate immune defense against microbial invasions. However, cathelicidins from crocodilians have not been extensively studied to date. In the present study, six novel cathelicidins (As-CATH1-6) were identified and characterized from the endangered Chinese alligator ( Alligator sinensis ). As-CATH1-6 exhibit no sequence similarity with any of the known cathelicidins. Structure analysis indicated that As-CATH1-3 adopt a random coil secondary conformation, whereas As-CATH4-6 were predicted to mainly adopt an amphipathic α-helix conformation. Among them, As-CATH4-6 exhibited potent, broad-spectrum and rapid antimicrobial activity by inducing the disruption of cell membrane integrity. They also exhibited strong ability to prevent the formation of bacterial biofilms and eradicate preformed biofilms. Furthermore, As-CATH4-6 exhibited potent anti-inflammatory activity by inhibiting the lipopolysaccharide (LPS)-induced production of nitric oxide (NO) and pro-inflammatory cytokines in mouse peritoneal macrophages. They directly neutralized LPS toxicity and therefore inhibited the binding of LPS to the TLR4 receptor and the subsequent activation of inflammatory response pathways. In a peritonitis mice model, As-CATH2-6 provided effective protection against bacterial infection through enhanced immune cell recruitment. In the host Chinese alligator, As-CATH1-6 are mainly expressed in immune organs and epithelial tissues. Bacterial infection significantly enhances their expression, which implies an important role in host anti-infective response. Taken together, the diversity and multiple functions of As-CATH1-6 partially reveal the powerful immune system of the Chinese alligator. © 2017 The Author(s). Published by Portland

The post-occipital spinal venous sinus of the Nile crocodile (Crocodylus niloticus: Its anatomy and use for blood sample collection and intravenous infusions

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Jan G. Myburgh

2014-05-01

Full Text Available The post-occipital sinus of the spinal vein is often used for the collection of blood samples from crocodilians. Although this sampling method has been reported for several crocodilian species, the technique and associated anatomy has not been described in detail in any crocodilian, including the Nile crocodile (Crocodylus niloticus. The anatomy of the cranial neck region was investigated macroscopically, microscopically, radiographically and by means of computed tomography. Latex was injected into the spinal vein and spinal venous sinus of crocodiles to visualise the regional vasculature. The spinal vein ran within the vertebral canal, dorsal to and closely associated with the spinal cord and changed into a venous sinus cranially in the post-occipital region. For blood collection, the spinal venous sinus was accessed through the interarcuate space between the atlas and axis (C1 and C2 by inserting a needle angled just off the perpendicular in the midline through the craniodorsal cervical skin, just cranial to the cranial borders of the first cervical osteoderms. The most convenient method of blood collection was with a syringe and hypodermic needle. In addition, the suitability of the spinal venous sinus for intravenous injections and infusions in live crocodiles was evaluated. The internal diameter of the commercial human epidural catheters used during these investigations was relatively small, resulting in very slow infusion rates. Care should be taken not to puncture the spinal cord or to lacerate the blood vessel wall using this route for blood collection or intravenous infusions.

Effect of aqueous extracts of alligator pear seed (Persea americana mill) on blood glucose and histopathology of pancreas in alloxan-induced diabetic rats.

Science.gov (United States)

Edem, Do; Ekanem, Is; Ebong, Pe

2009-07-01

Effects of aqueous extract of alligator pear seed on normal and alloxan-induced diabetic rats were investigated in 6 groups of rats (5 rats per group). Test groups were made diabetic with intra-peritoneal injection of alloxan and treated with 300 mg and 600 mg/kg body weight of alligator pear seed extract. Two non-diabetic groups were also administered with 300 mg and 600 mg/kg body weight extract. The levels of blood glucose were examined in all 6 experimental groups. In diabetic rats, blood glucose levels were significantly reduced (pblood glucose levels were significantly reduced (palligator pear seed may contribute significantly to the reduction of blood glucose levels and can be useful in the treatment of diabetes.

Ecological studies on the freshwater fishes of the Alligator Rivers Region, Northern Territory

International Nuclear Information System (INIS)

Bishop, K.A.; Allen, S.A.; Pollard, D.A.; Cook, M.G.

1986-01-01

The tropical climate of the Alligator Rivers Region of the Northern Territory has a distinctive Wet-Dry cycle resulting in seasonal flows in the creeks and rivers of its catchments. The present study, begun during August 1978, aimed at developing an ecological monitoring system that would detect changes in freshwater fish communities brought about by recent uranium mining and processing in the lowlands of the region

Intra-population variation in activity ranges, diel patterns, movement rates, and habitat use of American alligators in a subtropical estuary

Science.gov (United States)

Rosenblatt, Adam E.; Heithaus, Michael R.; Mazzotti, Frank J.; Cherkiss, Michael; Jeffery, Brian M.

2013-12-01

Movement and habitat use patterns are fundamental components of the behaviors of mobile animals and help determine the scale and types of interactions they have with their environments. These behaviors are especially important to quantify for top predators because they can have strong effects on lower trophic levels as well as the wider ecosystem. Many studies of top predator movement and habitat use focus on general population level trends, which may overlook important intra-population variation in behaviors that now appear to be common. In an effort to better understand the prevalence of intra-population variation in top predator movement behaviors and the potential effects of such variation on ecosystem dynamics, we examined the movement and habitat use patterns of a population of adult American alligators (Alligator mississippiensis) in a subtropical estuary for nearly four years. We found that alligators exhibited divergent behaviors with respect to activity ranges, movement rates, and habitat use, and that individualized behaviors were stable over multiple years. We also found that the variations across the three behavioral metrics were correlated such that consistent behavioral types emerged, specifically more exploratory individuals and more sedentary individuals. Our study demonstrates that top predator populations can be characterized by high degrees of intra-population variation in terms of movement and habitat use behaviors that could lead to individuals filling different ecological roles in the same ecosystem. By extension, one-size-fits-all ecosystem and species-specific conservation and management strategies that do not account for potential intra-population variation in top predator behaviors may not produce the desired outcomes in all cases.

A limnological survey of the Alligator Rivers Region. 1. Diatoms (Bacillariophyceae) of the region

International Nuclear Information System (INIS)

Thomas, D.P.

1983-08-01

This study was undertaken as part of a study of the algae of the Alligator Rivers Region in general, and of the Magela Creek in particular, to support an investigation into the possible use of native algae as an indicator of any changes in water quality which might occur as a result of uranium mining and milling in the Region

The Gulf Sturgeon in the Suwannee River - Questions and Answers

Science.gov (United States)

Sulak, Kenneth J.; Randall, Michael T.

2009-01-01

Sturgeons and paddlefishes are modern descendants of an ancient group of freshwater fishes, the Chondrostei (a group of bony fishes with mostly cartilaginous skeletons). Sturgeons evolved during the Age of the Dinosaurs, and have prospered in the large rivers and lakes of North America, Europe and Asia for 200 million years. Together with alligators and crocodiles, they survived the mass extinction at the end of the Mesozoic Era, when the dinosaurs and many other groups of animals disappeared forever. They originated prior to the creation of the Atlantic Ocean, when the Northern Hemisphere supercontinent Pangea broke into North America and Eurasia. Most sturgeons are highly specialized to feed in the sediment on small invertebrate prey, a radical evolutionary departure from most of their fish-eating ancestors.

Biochemical composition of the alligator pipefish, Syngnathoides biaculeatus (Bloch, 1785)

Science.gov (United States)

Sanaye, Sushant Vilas; Pawar, Ashwini Pandurang; Rivonker, Chandrasheker Umanath; Sreepada, Rayadurga Anantha; Ansari, Zakir Ali; Ram, Anirudh

2017-11-01

Considering the economic importance in traditional Chinese medicine (TCM) and lack of baseline information, we evaluated the proximate composition, fatty acid and amino acid profiles, trace element content and C:N ratio in the alligator pipefish, Syngnathoides biaculeatus. Amongst proximate principals, a crude protein formed the major biochemical component ((58.9±2.2)% dry weight). Mean percent concentrations (dry weight) of other components such as a total lipid (TL), ash and nitrogen-free extract measured were, (1.8±0.2)%, (19.2±2.2)% and (20.1±0.45)%, respectively. The fatty acid profile revealed the presence of 27 saturated fatty acids (SFA) with 13 straight-chained and 14 branched-chained, 28 unsaturated fatty acids (UFA) with 14 monounsaturated and 14 polyunsaturated and nine other minor fatty acids. Mean percent contributions of total SFAs and UFAs to TL were found to be (55.41±0.24)% and (44.05±0.25)%, respectively. Altogether, 16 different amino acids with an equal number of essential (EAA) and non-essential (NAA) ones were identified. Percent contributions by EAA and NAA to the total amino acid content were 38.11% and 61.89%, respectively. Trace metal concentrations in S. biaculeatus were generally low and their distribution followed the order, Mg>Fe>Zn>Mn>Cu>Cr>Ni>Hg>Co. The C:N ratio was (4.37±0.04)%. The profile of major biochemical constituents in alligator pipefish, S. biaculeatus revealed its potential use in TCM as well as a nutritional diet for human consumption. The results of the study would also form the basis for formulation and optimization of diets for the culture of S. biaculeatus.

Three crocodilian genomes reveal ancestral patterns of evolution among archosaurs

Science.gov (United States)

Green, Richard E; Braun, Edward L; Armstrong, Joel; Earl, Dent; Nguyen, Ngan; Hickey, Glenn; Vandewege, Michael W; St John, John A; Capella-Gutiérrez, Salvador; Castoe, Todd A; Kern, Colin; Fujita, Matthew K; Opazo, Juan C; Jurka, Jerzy; Kojima, Kenji K; Caballero, Juan; Hubley, Robert M; Smit, Arian F; Platt, Roy N; Lavoie, Christine A; Ramakodi, Meganathan P; Finger, John W; Suh, Alexander; Isberg, Sally R; Miles, Lee; Chong, Amanda Y; Jaratlerdsiri, Weerachai; Gongora, Jaime; Moran, Christopher; Iriarte, Andrés; McCormack, John; Burgess, Shane C; Edwards, Scott V; Lyons, Eric; Williams, Christina; Breen, Matthew; Howard, Jason T; Gresham, Cathy R; Peterson, Daniel G; Schmitz, Jürgen; Pollock, David D; Haussler, David; Triplett, Eric W; Zhang, Guojie; Irie, Naoki; Jarvis, Erich D; Brochu, Christopher A; Schmidt, Carl J; McCarthy, Fiona M; Faircloth, Brant C; Hoffmann, Federico G; Glenn, Travis C; Gabaldón, Toni; Paten, Benedict; Ray, David A

2015-01-01

To provide context for the diversifications of archosaurs, the group that includes crocodilians, dinosaurs and birds, we generated draft genomes of three crocodilians, Alligator mississippiensis (the American alligator), Crocodylus porosus (the saltwater crocodile), and Gavialis gangeticus (the Indian gharial). We observed an exceptionally slow rate of genome evolution within crocodilians at all levels, including nucleotide substitutions, indels, transposable element content and movement, gene family evolution, and chromosomal synteny. When placed within the context of related taxa including birds and turtles, this suggests that the common ancestor of all of these taxa also exhibited slow genome evolution and that the relatively rapid evolution of bird genomes represents an autapomorphy within that clade. The data also provided the opportunity to analyze heterozygosity in crocodilians, which indicates a likely reduction in population size for all three taxa through the Pleistocene. Finally, these new data combined with newly published bird genomes allowed us to reconstruct the partial genome of the common ancestor of archosaurs providing a tool to investigate the genetic starting material of crocodilians, birds, and dinosaurs. PMID:25504731

Multiple Paternity in a Reintroduced Population of the Orinoco Crocodile (Crocodylus intermedius) at the El Frío Biological Station, Venezuela.

Science.gov (United States)

Rossi Lafferriere, Natalia A; Antelo, Rafael; Alda, Fernando; Mårtensson, Dick; Hailer, Frank; Castroviejo-Fisher, Santiago; Ayarzagüena, José; Ginsberg, Joshua R; Castroviejo, Javier; Doadrio, Ignacio; Vilá, Carles; Amato, George

2016-01-01

The success of a reintroduction program is determined by the ability of individuals to reproduce and thrive. Hence, an understanding of the mating system and breeding strategies of reintroduced species can be critical to the success, evaluation and effective management of reintroduction programs. As one of the most threatened crocodile species in the world, the Orinoco crocodile (Crocodylus intermedius) has been reduced to only a few wild populations in the Llanos of Venezuela and Colombia. One of these populations was founded by reintroduction at Caño Macanillal and La Ramera lagoon within the El Frío Biological Station, Venezuela. Twenty egg clutches of C. intermedius were collected at the El Frío Biological Station for incubation in the lab and release of juveniles after one year. Analyzing 17 polymorphic microsatellite loci from 335 hatchlings we found multiple paternity in C. intermedius, with half of the 20 clutches fathered by two or three males. Sixteen mothers and 14 fathers were inferred by reconstruction of multilocus parental genotypes. Our findings showed skewed paternal contributions to multiple-sired clutches in four of the clutches (40%), leading to an overall unequal contribution of offspring among fathers with six of the 14 inferred males fathering 90% of the total offspring, and three of those six males fathering more than 70% of the total offspring. Our results provide the first evidence of multiple paternity occurring in the Orinoco crocodile and confirm the success of reintroduction efforts of this critically endangered species in the El Frío Biological Station, Venezuela.

Multiple Paternity in a Reintroduced Population of the Orinoco Crocodile (Crocodylus intermedius at the El Frío Biological Station, Venezuela.

Directory of Open Access Journals (Sweden)

Natalia A Rossi Lafferriere

Full Text Available The success of a reintroduction program is determined by the ability of individuals to reproduce and thrive. Hence, an understanding of the mating system and breeding strategies of reintroduced species can be critical to the success, evaluation and effective management of reintroduction programs. As one of the most threatened crocodile species in the world, the Orinoco crocodile (Crocodylus intermedius has been reduced to only a few wild populations in the Llanos of Venezuela and Colombia. One of these populations was founded by reintroduction at Caño Macanillal and La Ramera lagoon within the El Frío Biological Station, Venezuela. Twenty egg clutches of C. intermedius were collected at the El Frío Biological Station for incubation in the lab and release of juveniles after one year. Analyzing 17 polymorphic microsatellite loci from 335 hatchlings we found multiple paternity in C. intermedius, with half of the 20 clutches fathered by two or three males. Sixteen mothers and 14 fathers were inferred by reconstruction of multilocus parental genotypes. Our findings showed skewed paternal contributions to multiple-sired clutches in four of the clutches (40%, leading to an overall unequal contribution of offspring among fathers with six of the 14 inferred males fathering 90% of the total offspring, and three of those six males fathering more than 70% of the total offspring. Our results provide the first evidence of multiple paternity occurring in the Orinoco crocodile and confirm the success of reintroduction efforts of this critically endangered species in the El Frío Biological Station, Venezuela.

The orientation and navigation of juvenile alligators: evidence of magnetic sensitivity

Science.gov (United States)

Rodda, Gordon H.

1984-01-01

Displaced juvenile alligators, Alligator mississipiensis, were released on land in a 9 m diameter dodecagonal arena to test their ability to orient in the absence of terrestrial landmarks. Navigational ability seemed to improve with age. When displaced along a fairly direct route yearlings (age 7–14 months) compensated for their displacement, moving in the direction from the arena to their home sites. When displaced by a circuitous route, yearlings failed to compensate for their displacement, exhibiting instead simple compass orientation in a direction that would have returned them to water had they been released on land near the site where they were captured. The older juveniles were oriented in a homeward direction under all displacement and test conditions. The latter animals may have been using geomagnetic map information to select their homeward directions as the errors in their homeward bearings correlated with small deviations in the geomagnetic field's dip angle at the time of the test (1980r s=−0.6047,P=0.0131, all testsr s= −0.4652,P=0.0084). This effect appeared to depend on a very short-term assessment of geomagnetic conditions, as values measured 20 min before or 30 min after the tests began did not correlate with the directions the animals moved. The older juveniles appeared to use magnetically quiet hours on the night of their capture as the baseline from which to measure the geomagnetic deviations that occurred at the time of the arena test. The magnitude of the magnetic effect in the older animals suggests that the geomagnetic information may have been used to perform a ‘map’ step, as small fluctuations in dip angle correlated with much larger deviations in homeward bearings. In addition, the compass-oriented yearlings and the seemingly route-based behavior of the homeward-oriented yearlings did not appear to be influenced by geomagnetic conditions. These findings have many parallels in results obtained from bird orientation studies

Spermiogenesis in the imbricate alligator lizard, Barisia imbricata (Reptilia, Squamata, Anguidae).

Science.gov (United States)

Gribbins, Kevin M; Rheubert, Justin L; Touzinsky, Katherine; Hanover, Jessica; Matchett, Caroline L; Granados-González, Gisela; Hernández-Gallegos, Oswaldo

2013-06-01

Although the events of spermiogenesis are commonly studied in amniotes, the amount of research available for Squamata is lacking. Many studies have described the morphological characteristics of mature spermatozoa in squamates, but few detail the ultrastructural changes that occur during spermiogenesis. This study's purpose is to gain a better understanding of the subcellular events of spermatid development within the Imbricate Alligator Lizard, Barisia imbricata. The morphological data presented here represent the first complete ultrastructural study of spermiogenesis within the family Anguidae. Samples of testes from four specimens collected on the northwest side of the Nevado de Toluca, México, were prepared using standard techniques for transmission electron microscopy. Many of the ultrastructural changes occurring during spermiogenesis within B. imbricata are similar to that of other squamates (i.e., early acrosome formation, chromatin condensation, flagella formation, annulus present, and a prominent manchette). However, there are a few unique characteristics within B. imbricata spermatids that to date have not been described during spermiogenesis in other squamates. For example, penetration of the acrosomal granule into the subacrosomal space to form the basal plate of the perforatorium during round spermatid development, the clover-shaped morphology of the developing nuclear fossa of the flagellum, and the bulbous shape to the perforatorium are all unique to the Imbricate Alligator Lizard. These anatomical character differences may be valuable nontraditional data that along with more traditional matrices (such as DNA sequences and gross morphological data) may help elucidate phylogenetic relationships, which are historically considered controversial within Squamata. Copyright © 2013 Wiley Periodicals, Inc.

A new distributional record of alligator pipefish, Syngnathoides biaculeatus (Bloch, 1785) along Goa, central west coast of India

Digital Repository Service at National Institute of Oceanography (India)

Sanaye, S.V.; Rivonker, C.U.; Ansari, Z.A; Sreepada, R.A

Present study is based on a single male specimen of alligator pipefish, Syngnathoides biaculeatus (Bloch, 1785) collected from the bay-estuarine system of, Goa (central west coast of India) which is the new distributional record for this species. A...

In vivo locomotor strain in the hindlimb bones of alligator mississippiensis and iguana iguana: implications for the evolution of limb bone safety factor and non-sprawling limb posture

Science.gov (United States)

Blob; Biewener

1999-05-01

Limb postures of terrestrial tetrapods span a continuum from sprawling to fully upright; however, most experimental investigations of locomotor mechanics have focused on mammals and ground-dwelling birds that employ parasagittal limb kinematics, leaving much of the diversity of tetrapod locomotor mechanics unexplored. This study reports measurements of in vivo locomotor strain from the limb bones of lizard (Iguana iguana) and crocodilian (Alligator mississippiensis) species, animals from previously unsampled phylogenetic lineages with non-parasagittal limb posture and kinematics. Principal strain orientations and shear strain magnitudes indicate that the limb bones of these species experience considerable torsion during locomotion. This contrasts with patterns commonly observed in mammals, but matches predictions from kinematic observations of axial rotation in lizard and crocodilian limbs. Comparisons of locomotor load magnitudes with the mechanical properties of limb bones in Alligator and Iguana indicate that limb bone safety factors in bending for these species range from 5.5 to 10.8, as much as twice as high as safety factors previously calculated for mammals and birds. Limb bone safety factors in shear (3.9-5.4) for Alligator and Iguana are also moderately higher than safety factors to yield in bending for birds and mammals. Finally, correlations between limb posture and strain magnitudes in Alligator show that at some recording locations limb bone strains can increase during upright locomotion, in contrast to expectations based on size-correlated changes in posture among mammals that limb bone strains should decrease with the use of an upright posture. These data suggest that, in some lineages, strain magnitudes may not have been maintained at constant levels through the evolution of a non-sprawling posture unless the postural change was accompanied by a shift to parasagittal kinematics or by an evolutionary decrease in body size.

Nuclear microprobe analysis of lead profile in crocodile bones

Energy Technology Data Exchange (ETDEWEB)

Orlic, I. E-mail: ivo@ansto.gov.au; Siegele, R.; Hammerton, K.; Jeffree, R.A.; Cohen, D.D

2003-09-01

Elevated concentrations of lead were found in Australian free ranging saltwater crocodile (Crocodylus porosus) bone and flesh. Lead shots were found as potential source of lead in these animals. ANSTO's heavy ion nuclear microprobe was used to measure the distribution of Pb in a number of bones and osteoderms. The aim was to find out if elevated Pb concentration remains in growth rings and if the concentration is correlated with the blood levels recorded at the time. Results of our study show a very distinct distribution of accumulated Pb in bones and osteoderms as well as good correlation with the level of lead concentration in blood. To investigate influence of ion species on detection limits measurements of the same sample were performed by using 3 MeV protons, 9 MeV He ions and 20 MeV carbon ions. Peak to background ratios, detection limits and the overall 'quality' of obtained spectra are compared and discussed.

Crocodile bones as archives of pollution exposure: lead contamination in Kakadu National Park, and what's in Sweetheart's Osteoderms?

International Nuclear Information System (INIS)

Jeffree, R.A.; Markich, S.J.; Hammerton, K.M.; Russell, R.

2002-01-01

Experimental findings made it then possible to evaluate the hypothesis that the estuarine crocodile osteodermal laminations would record enhanced blood lead concentrations resulting from the ingestion of lead shot. At about 140 days following lead shot ingestion, two osteoderms were removed from each exposed and control animal. SIMS analysis of Pb-208 and Ca-42 signal intensities was then performed on sections that were prepared and analysed using similar methods previously used on field-collected specimens (Twining et al., 1999). These initial findings are consistent with the hypothesis that incremental laminations of the osteoderm will archive a lead signal that responds to enhanced levels of lead in the animal's blood during its life. SEM analysis identified the laminated structure of the osteoderm, however microprobe analysis did not detect appreciable amounts of even Ca and P, although the organic matrix was obviously present. It is proposed that this anomalous result is due to the preparatory tanning of the skin, in acid solution, that could be expected to leach elements from the organic matrix. An analogy is drawn with the decalcified skeletons in the bodies of the Druid sacrifices due their deposition in acid swamp waters in the UK. The challenge is now to sample osteoderms from large crocodiles in the Finniss River, preferably in close proximity to the Rum Jungle mine site, where any archived pollution signal would be more intense, and then repeat this analytical investigation of the osteodermal history of contaminant loadings

Experimental study on the effect of ingested lead shot on Estuarine crocodiles: significance for Finniss River field studies

International Nuclear Information System (INIS)

Hammerton, K.M.

2002-01-01

Lead has long been recognised as a cumulative metabolic poison in humans, domestic animals and wildlife. Because of the many industrial activities that have brought about its widespread distribution, lead is ubiquitous in the environment. For example, uranium mining at the Rum Jungle site on the Finniss River, Northern Territory, resulted in contamination of river sediments with lead. Today, lead levels remain at about 250 mg kg-1 of wet river sediment within the immediate vicinity of the mine. Another potential source of lead poisoning in wildlife is the use of lead gunshot for hunting. Mortality in wild waterfowl caused by the ingestion of spent lead shot has been recognised in North America and Europe for over a century. An experimental study was undertaken to assess the above hypothesis on the effects of lead in the environs of crocodiles. The specific effects of lead intoxication arise mainly from the interaction of lead with the enzymatic processes in the haem biosynthetic pathway. One of these enzymes, δ-aminolevulinic acid dehydratase (ALAD), catalyses the condensation of two molecules of aminolevulinic acid to produce the pyrrole, porphobilinogen, the building block of the haem molecule. ALAD is a metalloenzyme requiring zinc for activity and is inhibited by lead displacing the essential zinc. This inhibition of ALAD by lead has been used as a specific biomarker for lead poisoning in fish, birds and mammals. An assay system was developed for the measurement of ALAD activity in crocodilian blood. It was found that ALAD was inhibited by up to 90% during the first week after exposure of the crocodiles to lead shot. There was an inverse correlation between BPb and ALAD activity throughout the 42 week experimental period. BPb concentrations greater than 100 mg dL-1 produced significant inhibition of ALAD. The results indicated that ALAD inhibition could be used as a specific biomarker of lead toxicity in crocodiles

Conservation status and regional habitat priorities for the Orinoco crocodile: Past, present, and future.

Directory of Open Access Journals (Sweden)

Sergio A Balaguera-Reina

Full Text Available Conservation of large predator species has historically been a challenge because they often overlap in resource utilization with humans; furthermore, there is a general lack of in-depth knowledge of their ecology and natural history. We assessed the conservation status of the Orinoco crocodile (Crocodylus intermedius, defining regional habitat priorities/crocodile conservation units (RHP/CCU and regional research priorities (RRP for this species. We also estimated a species distribution model (SDM to define current suitable areas where the species might inhabit and/or that might be successfully colonized. The SDM area obtained with a suitable habitat probability ≥ 0.5 was 23,621 km2. Out of 2,562 km2 are included within protected areas in both Colombia (1,643 km2 and Venezuela (919 km2, which represents only 10.8% of C. intermedius' potential range. Areas such as Laguna de Chigüichigüe (flood plain lagoon exhibited an increase in population abundance. In contrast, localities such as the Cojedes and Manapire Rivers reported a significant reduction in relative abundance values. In Colombia, disparity in previous survey methods prevented accurate estimation of population trends. Only one study in this country described an increase over a 13 years span in the Ele, Lipa, and Cravo Norte River populations based on nest surveys. We defined 34 critical areas (16 in Colombia, 17 in Venezuela, and one covering both countries where we need to preserve/research/monitor and/or generate management actions, 10 RHP/CCU (six from Venezuela and four from Colombia and 24 RRP (11 from Venezuela, 12 from Colombia, and one in both countries. Caño Guaritico (Creek and the Capanaparo River in Venezuela and the Ele, Lipa, Cravo Norte River System and the Guayabero River in Colombia were defined as areas with the most optimal conditions for long-term preservation and maintenance of C. intermedius populations. We conclude that the conservation status of this species

Conservation status and regional habitat priorities for the Orinoco crocodile: Past, present, and future

Science.gov (United States)

Espinosa-Blanco, Ariel S.; Morales-Betancourt, Mónica A.; Seijas, Andrés E.; Lasso, Carlos A.; Antelo, Rafael; Densmore, Llewellyn D.

2017-01-01

Conservation of large predator species has historically been a challenge because they often overlap in resource utilization with humans; furthermore, there is a general lack of in-depth knowledge of their ecology and natural history. We assessed the conservation status of the Orinoco crocodile (Crocodylus intermedius), defining regional habitat priorities/crocodile conservation units (RHP/CCU) and regional research priorities (RRP) for this species. We also estimated a species distribution model (SDM) to define current suitable areas where the species might inhabit and/or that might be successfully colonized. The SDM area obtained with a suitable habitat probability ≥ 0.5 was 23,621 km2. Out of 2,562 km2 are included within protected areas in both Colombia (1,643 km2) and Venezuela (919 km2), which represents only 10.8% of C. intermedius’ potential range. Areas such as Laguna de Chigüichigüe (flood plain lagoon) exhibited an increase in population abundance. In contrast, localities such as the Cojedes and Manapire Rivers reported a significant reduction in relative abundance values. In Colombia, disparity in previous survey methods prevented accurate estimation of population trends. Only one study in this country described an increase over a 13 years span in the Ele, Lipa, and Cravo Norte River populations based on nest surveys. We defined 34 critical areas (16 in Colombia, 17 in Venezuela, and one covering both countries) where we need to preserve/research/monitor and/or generate management actions, 10 RHP/CCU (six from Venezuela and four from Colombia) and 24 RRP (11 from Venezuela, 12 from Colombia, and one in both countries). Caño Guaritico (Creek) and the Capanaparo River in Venezuela and the Ele, Lipa, Cravo Norte River System and the Guayabero River in Colombia were defined as areas with the most optimal conditions for long-term preservation and maintenance of C. intermedius populations. We conclude that the conservation status of this species is

Nesting of Morelet's crocodile, Crocodylus moreletii (Dumeril and Bibron), in Los Tuxtlas, Mexico.

Science.gov (United States)

Villegas, A; Mendoza, G D; Arcos-García, J L; Reynoso, V H

2017-11-01

We evaluated the nesting by Crocodylus moreletii in Lago de Catemaco, Veracruz, southeastern, Mexico. During the nesting and hatching seasons, we searched for nests along the northern margins of the lake and small associated streams. We investigated egg mortality by weekly monitoring each of the nests found, recording sign of predation (tracks and holes dug into the nest) and the effect of water level fluctuations. We not found differences to nest between inland or flooded zones. However, we found that egg size varied among nests. In nests built inland, predation was the major cause of egg mortality whereas flooding resulted in more deaths of eggs in the flooding zone. Flooding killed 25% of eggs monitored in this study. We suggest that to increase nest success in the Morelet's crocodile it is necessary to promote conservation of nesting areas around the lake, recently occupied by urban or tourist developments.

Remediating the South Alligator Valley uranium mining legacy

International Nuclear Information System (INIS)

Fawcett, M.; Waggitt, P.

2010-01-01

In late 1950s and early 1960s 13 uranium mines operated in the South Alligator Valley of Australia's Northern Territory. Once sales contracts had been filled the mines were abandoned and no remediation took place. In the 1980s the valley was designated as part of Stage 3 of the adjacent World Heritage-listed, Kakadu National Park. Proposals for remediation were only seriously put forward when the land was returned to the traditional Aboriginal owners, the Gunlom Land Trust, in 1996. Although they leased the land back so it would remain a part of Kakadu National Park the traditional Aboriginal owners required remediation to be complete by 2015. This paper tells the story of the development and implementation of the remediation process from the start of planning in 1998 to completion in 2009; and finally it describes the development of stakeholder relationships and the initial plans for long term stewardship. (author)

Environment Protection (Alligator Rivers Region) Act 1978, No.28

International Nuclear Information System (INIS)

1978-01-01

The main object of this Act is to provide for the appointment of a Supervising Scientist responsible for supervising protection of the environment in the Alligator Rivers Region of the Northern Territory from the effects of uranium mining operations. His functions include advising the competent Minister on the effects of uranium mining operations on the environment and on standards, practices and procedures for its protection and restoration. The Act also sets up a Co-ordinating Committee responsible for programmes for research into the environmental effects of such mining operations and also keeping under review standards, practices and procedures for environmental protection in relation thereto. Finally the Act provides for the establishment of a Research Institute managed by the Supervising Scientist, to promote and assist in research as well as to collect information on the environmental effects of uranium mining operations. (NEA) [fr

Nitrate induces a type 1 diabetic profile in alligator hatchlings.

Science.gov (United States)

Edwards, Thea M; Hamlin, Heather J; Freymiller, Haley; Green, Stephen; Thurman, Jenna; Guillette, Louis J

2018-01-01

Type 1 diabetes (T1D) is a chronic autoimmune disease that affects 1 in 300 children by age 18. T1D is caused by inflammation-induced loss of insulin-producing pancreatic beta cells, leading to high blood glucose and a host of downstream complications. Although multiple genes are associated with T1D risk, only 5% of genetically susceptible individuals actually develop clinical disease. Moreover, a growing number of T1D cases occur in geographic clusters and among children with low risk genotypes. These observations suggest that environmental factors contribute to T1D etiology. One potential factor, supported primarily by epidemiological studies, is the presence of nitrate and nitrite in drinking water. To test this hypothesis, female hatchling alligators were exposed to environmentally relevant concentrations of nitrate in their tank water (reference, 10mg/L, or 100mg/L NO 3 -N) from hatch through 5 weeks or 5 months of age. At each time point, endpoints related to T1D were investigated: plasma levels of glucose, triglycerides, testosterone, estradiol, and thyroxine; pancreas, fat body, and thyroid weights; weight gain or loss; presence of immune cells in the pancreas; and pancreatic beta cell number, assessed by antibody staining of nkx6.1 protein. Internal dosing of nitrate was confirmed by measuring plasma and urine nitrate levels and whole blood methemoglobin. Cluster analysis indicated that high nitrate exposure (most animals exposed to 100mg/L NO3-N and one alligator exposed to 10mg/L NO3-N) induced a profile of endpoints consistent with early T1D that could be detected after 5 weeks and was more strongly present after 5 months. Our study supports epidemiological data correlating elevated nitrate with T1D onset in humans, and highlights nitrate as a possible environmental contributor to the etiology of T1D, possibly through its role as a nitric oxide precursor. Copyright © 2017 Elsevier Inc. All rights reserved.

Diatoms of the jukskei-crocodile river system (transvaal, republic of South Africa): a preliminary check list

CSIR Research Space (South Africa)

Schoeman, FR

1982-01-01

Full Text Available : V & R Printers. SCHOEMAN, F. R., 1976. Diatom indicator groups in the assessment of water quality in the Jukskei-Crocodile River system (Transvaal, Republic of South Afri ca). J. Limnol. Soc. yth. Afr. 2: 21?24. SCHOEMAN, F. R., 1979. Diatoms... groups of diatom spe cies have been successfully used as an index of the quality of running waters (Lange-Bertalot, 1978a; 1979a; 1979b; Schoeman, 1976; 1979). However, the successful determination of water quality using diatoms as indicators...

Diets and abundances of aquatic and semi-aquatic reptiles in the Alligator Rivers Region

International Nuclear Information System (INIS)

Shine, R.

1986-01-01

The mining and milling of uranium in the Alligator River Region in the Northern Territory has raised the possibility that heavy metals and radionuclides might escape into the aquatic system and be accumulated by the reptilian fauna. Aquatic and semi-aquatic reptiles are regularly eaten by Aboriginal people of the region, and data on diets and reproduction of these species, as well as on their dispersion and abundance, are essential before the possibility that reptiles might act as pathways for these contaminants to Aboriginals can be assessed. The objectives of this study were to provide quantitative data on the diets of filesnakes, sand goannas and water goannas, to provide information on seasonal changes in their abundance and distribution within the Magela Creek system; and to describe their reproductive cycles

Evaluating potential effects of widening US 64 on the black bear population of Alligator River National Wildlife Refuge, Dare County, North Carolina.

Science.gov (United States)

2011-12-21

This report summarizes research conducted along US Highway 64 (US 64) and US Highway 264 (US 264) in Alligator : River National Wildlife Refuge (ARNWR), Dare County, NC regarding the proposed expansion of US 64. The study site : included the areas ad...

Case history of the discovery of the Jabiluka uranium deposits, East Alligator River region, Northern Territory of Australia

International Nuclear Information System (INIS)

Rowntree, J.C.; Mosher, D.V.

1976-01-01

Pancontinental Mining Limited acquired exploration rights over an area in the East Alligator River Region, Northern Territory, Australia, in 1970. Subsequently, Getty Oil Development Company Limited acquired a substantial minority interest in the property. The Jabiluka deposits were discovered during the course of exploration and are currently the largest of the four major uranium deposits in the East Alligator River Region. This region at present contains 24% of the western world's reasonably assured resources of uranium. The exploration techniques employed during primary and secondary exploration on the property between 1971 and 1975 and during the delineation of the Jabiluka deposits are discussed in detail. The case history illustrates the exploration philosophy which was successfully employed on the Jabiluka property. The philosophy encompasses the following points: The need for an assessment on the limits of airborne radiometric surveys; the necessity for detection and evaluation of point source anomalies; the necessity for exploration along extensions of favourable lithologies; and the desirability of modification of exploration techniques on different types of anomalies. Some aspects of this philosophy may be useful in exploration for similar stratabound uranium deposits in other areas. (author)

Potential of the Kakadu National Park Region

Energy Technology Data Exchange (ETDEWEB)

1988-01-01

The Committee reviewed the potential of the Kakadu National Park region in the Northern Territory with particular reference to the nature of the resources available for exploitation and the impact of utilisation of these resources, particularly mining and tourism. Individual chapters discuss the Park, tourism, mineral resources (particularly the environmental and economic impacts of the Ranger Uranium Mine and the potential impacts of mining the Koongarra and Jabiluka deposits), the town of Jabiru, commercial fishing, other issues (the scientific resource, crocodiles, introduced species and fire), and park management and control (including a review of the role of the Office of the Supervising Scientist for the Alligator Rivers Region). A number of recommendations are made and the dissenting report of three of the Committee's members is included.

The potential of the Kakadu National Park Region

International Nuclear Information System (INIS)

1988-11-01

The Committee reviewed the potential of the Kakadu National Park region in the Northern Territory with particular reference to the nature of the resources available for exploitation and the impact of utilisation of these resources, particularly mining and tourism. Individual chapters discuss the Park, tourism, mineral resources (particularly the environmental and economic impacts of the Ranger Uranium Mine and the potential impacts of mining the Koongarra and Jabiluka deposits), the town of Jabiru, commercial fishing, other issues (the scientific resource, crocodiles, introduced species and fire), and park management and control (including a review of the role of the Office of the Supervising Scientist for the Alligator Rivers Region). A number of recommendations are made and the dissenting report of three of the Committee's members is included

Pathological Features of Fatal Crocodile Attacks in Northern Australia, 2005-2014.

Science.gov (United States)

Sinton, Terence J; Byard, Roger W

2016-11-01

Eleven deaths from crocodile attacks in the Northern Territory, Australia were reviewed. The male:female ratio was 8:3; age range-10-62 years, average 29.4 years. Four children were included (one boy and three girls, aged 10, 11, and two at 12 years), and there were seven aboriginal victims (64%). The attacks were witnessed in eight cases with the victims swimming in freshwater N = 5, standing on a river bank N = 1, fishing in fresh water N = 1, or diving in the sea N = 1. At autopsy, several distinct patterns of injury were observed ranging from complete traumatic disruption of the body with only incomplete remains for examination (N = 5), to crushing of the head with fractures of the skull (N = 4), crushing of the chest with fractures of the ribs and sternum (N = 2), and avulsion of limbs (N = 4). In one case, there was decapitation. Autopsy evaluations were complicated by decomposition and loss of body parts. © 2016 American Academy of Forensic Sciences.

Geomorphological assessment of sites and impoundments for the long term containment of uranium mill tailings in the Alligator Rivers Region

International Nuclear Information System (INIS)

East, T.J.

1986-01-01

This paper presents a program of current and future research into those geomorphological processes likely to affect the long term containment of uranium mill tailings in the Alligator Rivers Region of the Northern Territory. Research is directed at three main areas: identification of geomorphic hazards at proposed impoundment sites; determination of erosion rates on impoundment slopes; and prediction of patterns of fluvial dispersal of released tailings. Each necessitates consideration of present and future geomorphic processes

[Bilateral "crocodile tears syndrome" associated with Melkersson-Rosenthal syndrome--case report].

Science.gov (United States)

Owecki, Michał K; Kapelusiak-Pielok, Magdalena; Kowal, Piotr; Kozubski, Wojciech

2006-01-01

We present a rare case of bilateral crocodile tears syndrome (CTS) in the course of Melkersson-Rosenthal syndrome. Melkersson-Rosenthal syndrome is characterised by a triad of recurrent orofacial swelling, relapsing facial paralysis, and fissured tongue. The classic triad is infrequent and oligosymptomatic variants are seen more frequently. CTS is a rare complication of facial nerve paralysis characterised by inappropriate lacrimation on the side of the palsy in response to salivary stimuli. It results from aberrant reinnervation of the lacrimal gland by salivary parasympathetic fibres. The therapeutic approach for an acute bout of Melkersson-Rosenthal syndrome consists mainly of steroid administration. CTS management is composed of anticholinergic drugs and surgical procedures. Botulin toxin injection into the lacrimal gland is the most modern therapeutic option. In the case presented CTS developed in a 50-year-old man after 5 incidents of facial palsy due to Melkersson-Rosenthal syndrome. The case deserves attention due to the rarity of the observed symptoms and signs.

Population assessment of the American crocodile, Crocodylus acutus (Crocodilia: Crocodylidae on the Pacific coast of Costa Rica

Directory of Open Access Journals (Sweden)

Laurie A. Mauger

2012-12-01

Full Text Available The American crocodile, Crocodylus acutus, is widely distributed in the American neotropics. It is endangered throughout most of its range and is listed as vulnerable by the International Union for the Conservation of Natural Fauna and Flora (IUCN and on Appendix I of the Convention for the International Trade in Endangered Species of Wild Flora and Fauna (CITES. Despite this listing, there are few published reports on population status throughout most of its range. We investigated the status of the C. acutus, at several locations along the Pacific coast of Costa Rica. We carried out spotlight and nesting surveys from 2007-2009 along the Costa Rican Pacific coast in four distinct areas, coastal areas of Las Baulas (N=40 and Santa Rosa (N=9 National Parks and the Osa Conservation Area (N=13, and upriver in Palo Verde National Park (N=11. We recorded crocodile locations and standard environmental data at each observation. Encounter rates, population structure, distribution within each area and data on successful nesting (presence of hatchlings, nests, etc were determined. We attempted to capture all crocodiles to record standard morphometrics. A total of 586 crocodiles were observed along 185.8km of survey route. The majority of animals encountered (54.9% were either hatchlings (El cocodrilo americano, Crocodylus acutus, se encuentra ampliamente distribuido en el neotrópico Americano y hay pocos estudios publicados sobre el estado de sus poblaciones en la mayor parte de su rango de distribución. Investigamos el estado del Cocodylus acutus en varias ubicaciones a lo largo de la costa del Pacífico de Costa Rica. Se realizaron muestreos nocturnos y de anidación a lo largo de la Costa Pacífica de Costa Rica en cuatro áreas en particular desde 2007-2009,’áreas costeras en los Parque Nacionales de Las Baulas (N=40 y Santa Rosa (N=9, y en el Área de Conservación de la Osa (N=13 y en el curso alto del Parque Nacional de Palo Verde (N=11. Se

Alligator Rivers Region Research Institute: annual research summary 1989-1990

International Nuclear Information System (INIS)

1991-01-01

The Alligator Rivers Region Research Institute (ARRRI) research activities are associated with an assessment of environmental effect of mining in the region. While emphasis on baseline research is now much reduced, some projects are still necessary because of significant changes in the Magela Creek system, because new areas of proposed mining have been identified (e.g. Coronation Hill) and because the emphasis now being placed on rehabilitation research requires a sound knowledge of the Region's flora. The ARRRI rehabilitation research program has concentrated on the Ranger mine site, principally because it is at a critical planning stage where detailed research information is required. With regard to the development of techniques, research at the Institute has led to the development of specific analytical methods or protocols that can be used in assessing environmental impact. 39 tabs., 42 figs

Extended mitogenomic phylogenetic analyses yield new insight into crocodylian evolution and their survival of the Cretaceous-Tertiary boundary.

Science.gov (United States)

Roos, Jonas; Aggarwal, Ramesh K; Janke, Axel

2007-11-01

The mitochondrial genomes of the dwarf crocodile, Osteolaemus tetraspis, and two species of dwarf caimans, the smooth-fronted caiman, Paleosuchus trigonatus, and Cuvier's dwarf caiman, Paleosuchus palpebrosus, were sequenced and included in a mitogenomic phylogenetic study. The phylogenetic analyses, which included a total of ten crocodylian species, yielded strong support to a basal split between Crocodylidae and Alligatoridae. Osteolaemus fell within the Crocodylidae as the sister group to Crocodylus. Gavialis and Tomistoma, which joined on a common branch, constituted a sister group to Crocodylus/Osteolaemus. This suggests that extant crocodylians are organized in two families: Alligatoridae and Crocodylidae. Within the Alligatoridae there was a basal split between Alligator and a branch that contained Paleosuchus and Caiman. The analyses also provided molecular estimates of various divergences applying recently established crocodylian and outgroup fossil calibration points. Molecular estimates based on amino acid data placed the divergence between Crocodylidae and Alligatoridae at 97-103 million years ago and that between Alligator and Caiman/Paleosuchus at 65-72 million years ago. Other crocodilian divergences were placed after the Cretaceous-Tertiary boundary. Thus, according to the molecular estimates, three extant crocodylian lineages have their roots in the Cretaceous. Considering the crocodylian diversification in the Cretaceous the molecular datings suggest that the extinction of the dinosaurs was also to some extent paralleled in the crocodylian evolution. However, for whatever reason, some crocodylian lineages survived into the Tertiary.

Nesting of Morelet’s crocodile, Crocodylus moreletii (Dumeril and Bibron, in Los Tuxtlas, Mexico

Directory of Open Access Journals (Sweden)

A. Villegas

2017-03-01

Full Text Available Abstract We evaluated the nesting by Crocodylus moreletii in Lago de Catemaco, Veracruz, southeastern, Mexico. During the nesting and hatching seasons, we searched for nests along the northern margins of the lake and small associated streams. We investigated egg mortality by weekly monitoring each of the nests found, recording sign of predation (tracks and holes dug into the nest and the effect of water level fluctuations. We not found differences to nest between inland or flooded zones. However, we found that egg size varied among nests. In nests built inland, predation was the major cause of egg mortality whereas flooding resulted in more deaths of eggs in the flooding zone. Flooding killed 25% of eggs monitored in this study. We suggest that to increase nest success in the Morelet’s crocodile it is necessary to promote conservation of nesting areas around the lake, recently occupied by urban or tourist developments.

Six-monthly report on surveillance of environmental monitoring in Alligator Rivers Region for the period 1 April-30 September 1988

International Nuclear Information System (INIS)

1988-01-01

This report outlines the activities of Northern Territory Government authorities (Department of Mines and Energy (DME), Conservation Commission and Department of Health and Community Services (DHCS) in meeting their responsibilities for surveillance of environmental monitoring in the Alligator Rivers Region for the period 1 April to 30 September 1988. The responsibility for DME activities derives principally from the Mining Act, the Mines Safety Control Act, the Control of Waters Act and the Uranium Mining (Environment Control) Act, referred to in this report as the UMEC Act. The Land Conservation Unit (LCU) of the Conservation Commission and the Occupational and Environmental Health Branch of DHCS, furnish technical advice to the Alligator Rivers Region Unit of DME, which then collates the data for Authorizations, approvals and compliance reports. The responsibilities of the Conservation Commission derive from the Soil Conservation and Land Utilization Act. DHCS activities derive from, in addition to the relevant Mines Acts, the Silicosis and Tuberculosis (Mine Workers and Prospectors) Act, Radiation (Safety Control) Act and the Public Health Act

Injuries, envenomations and stings from exotic pets.

Science.gov (United States)

Warwick, Clifford; Steedman, Catrina

2012-07-01

A variety of exotic vertebrate and invertebrate species are kept as 'pets' including fishes, amphibians (for example, frogs and toads), reptiles (turtles, crocodiles, lizards and snakes), birds, mammals (for example, primates, civets, and lions), and invertebrates (for example spiders, scorpions, and centipedes), and ownership of some of these animals is rising. Data for 2009-2011 suggest that the number of homes with reptiles rose by approximately 12.5%. Recent surveys, including only some of these animals, indicated that they might be present in around 18.6% of homes (equal to approximately 42 million animals of which around 40 million are indoor or outdoor fish). Many exotic 'pets' are capable of causing injury or poisoning to their keepers and some contacts prove fatal. We examined NHS Health Episode Statistics for England using selected formal categories for hospital admissions and bed days for 2004-2010 using the following categories of injury, envenomation or sting; bitten or struck by crocodile or alligator; bitten or crushed by other reptiles: contact with venomous snakes and lizards; contact with scorpions. Between 2004 and 2010 these data conservatively show a total of 760 full consultation episodes, 709 admissions and 2,121 hospital bed days were associated with injuries probably from exotic pets. Injuries, envenomations and stings from exotic pets constitute a small but important component of emerging medical problems. Greater awareness of relevant injuries and medical sequelae from exotic pet keeping may help medics formulate their clinical assessment and advice to patients.

Thermoregulation and temperature relations of alligators and other large ectotherms inhabiting thermally stressed habitats. Annual progress report, July 1, 1975--June 30, 1976

Energy Technology Data Exchange (ETDEWEB)

Spotila, J.R.

1976-03-01

The effects of radiation and convection on the equilibrium body temperatures of alligators have been determined. Gaping has been shown to be an effective thermoregulatory device for retarding heat gain in the heads of these animals. Initial time dependent experiments have been completed and ketamine hydrochloride has been shown to be an effective anesthetic for alligators. Evaporative water loss rates have been measured as a function of size, temperature and wind speed for the turtle Chrysemys scripta. Convection coefficients have been determined and climate spaces are being formulated. Field studies are under way at the Savannah River Ecology Laboratory. Convection coefficients for largemouth bass, Micropterus salmoides change as a function of temperature and water speed. Steady state heat energy budgets have been computed for this fish. The effects of arsenic and temperature on the temperature tolerance of larval muskellunge, Esox masquinongy, have been determined. The thermal tolerances of several species of minnows have also been measured. The role of the skin in the control of evaporation from amphibians and reptiles has been assessed. During the past year one article has been published, two are in press, one is in review, and eight are in preparation. Five masters theses will be completed by July 1976.

Thermoregulation and temperature relations of alligators and other large ectotherms inhabiting thermally stressed habitats. Annual progress report, July 1, 1975--June 30, 1976

International Nuclear Information System (INIS)

Spotila, J.R.

1976-03-01

The effects of radiation and convection on the equilibrium body temperatures of alligators have been determined. Gaping has been shown to be an effective thermoregulatory device for retarding heat gain in the heads of these animals. Initial time dependent experiments have been completed and ketamine hydrochloride has been shown to be an effective anesthetic for alligators. Evaporative water loss rates have been measured as a function of size, temperature and wind speed for the turtle Chrysemys scripta. Convection coefficients have been determined and climate spaces are being formulated. Field studies are under way at the Savannah River Ecology Laboratory. Convection coefficients for largemouth bass, Micropterus salmoides change as a function of temperature and water speed. Steady state heat energy budgets have been computed for this fish. The effects of arsenic and temperature on the temperature tolerance of larval muskellunge, Esox masquinongy, have been determined. The thermal tolerances of several species of minnows have also been measured. The role of the skin in the control of evaporation from amphibians and reptiles has been assessed. During the past year one article has been published, two are in press, one is in review, and eight are in preparation. Five masters theses will be completed by July 1976

Direct comparison of the electronic coupling efficiency of sulfur and selenium alligator clips for molecules adsorbed onto gold electrodes

International Nuclear Information System (INIS)

Patrone, L.; Palacin, S.; Bourgoin, J.P.

2003-01-01

Scanning tunneling microscopy experiments have been performed to compare the electronic coupling provided by S and by Se used as alligator clips for bisthiol- and biselenol-terthiophene molecules adsorbed onto gold. The molecules were inserted in a dodecanethiol (DT) self-assembled monolayer. Their apparent height above the dodecanethiol matrix was used as a measure of the electronic coupling strength corresponding to S and Se, respectively. We show that the insertion behaviors of the two molecules are qualitatively the same, and that Se provides systematically a better coupling link than S, whatever the tunneling conditions

Can isotope markers differentiate between wild and captive reptile populations? A case study based on crocodile lizards (Shinisaurus crocodilurus from Vietnam

Directory of Open Access Journals (Sweden)

Mona van Schingen

2016-04-01

Full Text Available The international wildlife trade in allegedly “captive-bred” specimens has globally increased during recent years, while the legal origin of respective animals frequently remains doubtful. Worldwide, authorities experience strong challenges to effectively control the international trade in CITES-listed species and are struggling to uncover fraudulent claims of “captive-breeding”. Forensic analytical methods are being considered as potential tools to investigate wildlife crime. The present case study is the first of its kind in reptiles that investigates the application of δ13C and δ15N stable isotope ratios to discriminate between captive and wild crocodile lizards from Vietnam. The CITES-listed crocodile lizard Shinisaurus crocodilurus is listed as endangered on the IUCN Red List mainly due to habitat loss and unsustainable exploitation for the international pet trade. Our results revealed significant differences in the composition of the two tested isotope systems between captive and wild individuals. Isotope values of skin samples from captive specimens were significantly enriched in 13C and 15N as compared to specimens from the wild. We also used the weighted k-Nearest Neighbor classifier to assign simulated samples back to their alleged place of origin and demonstrated that captive bred individuals could be distinguished with a high degree of accuracy from specimens that were not born in captivity. We conclude that isotope analysis appears to be highly attractive as a forensic tool to reduce laundering of wild caught lizards via breeding farms, but acknowledge that this potential might be limited to range restricted or ecologically specialist species.

Measuring behavioral responses of sea turtles, saltwater crocodiles, and crested terns to drone disturbance to define ethical operating thresholds.

Science.gov (United States)

Bevan, Elizabeth; Whiting, Scott; Tucker, Tony; Guinea, Michael; Raith, Andrew; Douglas, Ryan

2018-01-01

Drones are being increasingly used in innovative ways to enhance environmental research and conservation. Despite their widespread use for wildlife studies, there are few scientifically justified guidelines that provide minimum distances at which wildlife can be approached to minimize visual and auditory disturbance. These distances are essential to ensure that behavioral and survey data have no observer bias and form the basis of requirements for animal ethics and scientific permit approvals. In the present study, we documented the behaviors of three species of sea turtle (green turtles, Chelonia mydas, flatback turtles, Natator depressus, hawksbill turtles, Eretmochelys imbricata), saltwater crocodiles (Crocodylus porosus), and crested terns (Thalasseus bergii) in response to a small commercially available (1.4 kg) multirotor drone flown in Northern Territory and Western Australia. Sea turtles in nearshore waters off nesting beaches or in foraging habitats exhibited no evasive behaviors (e.g. rapid diving) in response to the drone at or above 20-30 m altitude, and at or above 10 m altitude for juvenile green and hawksbill turtles foraging on shallow, algae-covered reefs. Adult female flatback sea turtles were not deterred by drones flying forward or stationary at 10 m altitude when crawling up the beach to nest or digging a body pit or egg chamber. In contrast, flyovers elicited a range of behaviors from crocodiles, including minor, lateral head movements, fleeing, or complete submergence when a drone was present below 50 m altitude. Similarly, a colony of crested terns resting on a sand-bank displayed disturbance behaviors (e.g. flight response) when a drone was flown below 60 m altitude. The current study demonstrates a variety of behavioral disturbance thresholds for diverse species and should be considered when establishing operating conditions for drones in behavioral and conservation studies.

Measuring behavioral responses of sea turtles, saltwater crocodiles, and crested terns to drone disturbance to define ethical operating thresholds

Science.gov (United States)

Whiting, Scott; Tucker, Tony; Guinea, Michael; Raith, Andrew; Douglas, Ryan

2018-01-01

Drones are being increasingly used in innovative ways to enhance environmental research and conservation. Despite their widespread use for wildlife studies, there are few scientifically justified guidelines that provide minimum distances at which wildlife can be approached to minimize visual and auditory disturbance. These distances are essential to ensure that behavioral and survey data have no observer bias and form the basis of requirements for animal ethics and scientific permit approvals. In the present study, we documented the behaviors of three species of sea turtle (green turtles, Chelonia mydas, flatback turtles, Natator depressus, hawksbill turtles, Eretmochelys imbricata), saltwater crocodiles (Crocodylus porosus), and crested terns (Thalasseus bergii) in response to a small commercially available (1.4 kg) multirotor drone flown in Northern Territory and Western Australia. Sea turtles in nearshore waters off nesting beaches or in foraging habitats exhibited no evasive behaviors (e.g. rapid diving) in response to the drone at or above 20–30 m altitude, and at or above 10 m altitude for juvenile green and hawksbill turtles foraging on shallow, algae-covered reefs. Adult female flatback sea turtles were not deterred by drones flying forward or stationary at 10 m altitude when crawling up the beach to nest or digging a body pit or egg chamber. In contrast, flyovers elicited a range of behaviors from crocodiles, including minor, lateral head movements, fleeing, or complete submergence when a drone was present below 50 m altitude. Similarly, a colony of crested terns resting on a sand-bank displayed disturbance behaviors (e.g. flight response) when a drone was flown below 60 m altitude. The current study demonstrates a variety of behavioral disturbance thresholds for diverse species and should be considered when establishing operating conditions for drones in behavioral and conservation studies. PMID:29561901

Non-electrical uses of geothermal energy

Energy Technology Data Exchange (ETDEWEB)

Barber E.; Fanelli, M.

1977-01-01

A comprehensive review covers the recognition of natural hot fluids in ancient times and their use for therapeutic baths; the first production of electricity from geothermal steam at Larderello, Italy, in 1904; the widespread geographical occurrence of geothermal fluids; exploration techniques; the extraction of geothermal fluids and their uses in spas, agriculture, aquaculture, domestic heating, and industrial applications; geothermal greenhouse heating world-wide; geothermal heating of animal and poultry houses, in culture of alligators and crocodiles (in Atagawa, Japan), and in fish culture; piping arrangements for district heating, and a tabulation of district heating installations world-wide; downhole exchanger systems used in Klamath Falls, Oregon, for domestic heating; industrial heating applications; and methods of disposal of geothermal fluids. Maps, diagrams, graphs, photographs, tables, and 48 references are included.

Genetic diversity and population demography of the Chinese crocodile lizard (Shinisaurus crocodilurus in China.

Directory of Open Access Journals (Sweden)

Huayuan Huang

Full Text Available The Chinese crocodile lizard Shinisaurus crocodilurus is a critically endangered species, listed in Appendix II of CITES. Its populations and habitat in China have undergone significant changes in recent years. Understanding the genetic variability and phylogeography of this species is very important for successful conservation. In this study, samples were taken from 11 wild ponds and two captive populations in China. We sequenced mitochondrial CYTB, partial ND6, and partial tRNA-Glu and genotyped 10 microsatellite loci. Our analyses of these data showed low genetic variability, no strong isolation caused by distance, and a lack of a phylogeographic structure in this species. Based on our results, the basal divergence between two clades of S. crocodilurus in China may have been caused by the formation of the Pearl River system. We found a population expansion in one of these clades. Microsatellite analysis indicated the presence of three clusters, separated by significant genetic differences. We found that most individuals in the two captive populations were from the Luokeng (Guangdong and Guangxi wild source populations, respectively.

Dwarfism and feeding behaviours in Oligo–Miocene crocodiles from Riversleigh, northwestern Queensland, Australia

Directory of Open Access Journals (Sweden)

Michael Stein

2016-02-01

Full Text Available Instances of dwarfism in the fossil record are of interest to palaeontologists because they often provide insight into aspects of palaeoecology. Fossil species of Australian-Pacific mekosuchine genus Mekosuchus have been described as dwarf, primarily terrestrial crocodiles, in contrast with the nearly ubiquitous semi-aquatic habitus of extant crocodilians (Willis 1997. This hypothesis has been difficult to test because of limited knowledge of the cranial and postcranial skeleton of extinct taxa and the continuous nature of crocodilian growth. New crocodilian vertebral material from Riversleigh, northwestern Queensland, tentatively referred to Mekosuchus whitehunterensis Willis, 1997, displays morphological maturity indicative of adult snout-vent length little over a half-meter, proportionally smaller than extant dwarf taxa. Further, this material displays morphology that indicates a relatively large epaxial neck musculature for its body-size. These attributes suggest this dwarf mekosuchine employed unusual feeding behaviours. The ability to perform normal death-roll, de-fleshing behaviours would be limited in a mekosuchine of such small size. Given the powerful neck muscles and other anatomical features, it is more likely that this mekosuchine killed and/or dismembered its prey using a relatively forceful lifting and shaking of the head.

INTRAVAL phase 2, test case 8. Alligator Rivers Natural Analogue - Modelling of uranium transport in the weathered zone at Koongarra (Australia). Progress report

NARCIS (Netherlands)

van der Weerd H; Hassanizadeh SM; Richardson-van der Poel MA; LBG

1993-01-01

A study of uranium transport in the Koongarra site of Alligator Rivers Uranium deposit (Australia) is carried out. The analysis of the solid phase uranium concentration measured at various depths provides a useful picture of the dispersion process. Results of this analysis seem to support the

On the Morphological Description of Tracheal and Esophageal Displacement and Its Phylogenetic Distribution in Avialae

Science.gov (United States)

Klingler, Jeremy J.

2016-01-01

This research examines the evolution and phylogenetic distribution of a peculiar and often overlooked character seen in birds, herein called tracheal and esophageal displacement. Tracheal and esophageal displacement refers to an asymmetrically situated trachea and/or esophagus along the length of the neck. This contrasts with what would be perceived as the “normal” (midsagittal) placement of these organs, wherein the two organs are situated along the ventral midline of the neck with no deviation. A total of forty-two bird species were examined (thirty-six of which came from dissections whereas six came from comments from previous literature or personal observations), as well as turtles, lizards, crocodylians, and mammals. This study found that essentially all birds have a laterally displaced trachea and/or esophagus. Lizards and mammals were seen to have normal, midsagittally placed tracheae and esophagi. Crocodylians were interesting in that alligators were defined by a normally situated trachea and esophagus whereas some crocodiles were characterized by displacement. In birds, the displacement may occur gradually along the neck, or it may happen immediately upon exiting the oropharynx. Displacement of these organs in birds is the result of a heavily modified neck wherein muscles that restrict mobility of the trachea and esophagus in lizards, alligators, and mammals (e.g., m. episternocleidomastoideus, m. omohyoideus, and m. sternohyoideus) no longer substantially restrict positions of the trachea and esophagus in birds. Rather, these muscles are modified in ways which may assist with making tracheal movements. The implications of this study may provide interesting insights for future comparisons in extinct taxa. PMID:27648952

On the Morphological Description of Tracheal and Esophageal Displacement and Its Phylogenetic Distribution in Avialae.

Directory of Open Access Journals (Sweden)

Jeremy J Klingler

Full Text Available This research examines the evolution and phylogenetic distribution of a peculiar and often overlooked character seen in birds, herein called tracheal and esophageal displacement. Tracheal and esophageal displacement refers to an asymmetrically situated trachea and/or esophagus along the length of the neck. This contrasts with what would be perceived as the "normal" (midsagittal placement of these organs, wherein the two organs are situated along the ventral midline of the neck with no deviation. A total of forty-two bird species were examined (thirty-six of which came from dissections whereas six came from comments from previous literature or personal observations, as well as turtles, lizards, crocodylians, and mammals. This study found that essentially all birds have a laterally displaced trachea and/or esophagus. Lizards and mammals were seen to have normal, midsagittally placed tracheae and esophagi. Crocodylians were interesting in that alligators were defined by a normally situated trachea and esophagus whereas some crocodiles were characterized by displacement. In birds, the displacement may occur gradually along the neck, or it may happen immediately upon exiting the oropharynx. Displacement of these organs in birds is the result of a heavily modified neck wherein muscles that restrict mobility of the trachea and esophagus in lizards, alligators, and mammals (e.g., m. episternocleidomastoideus, m. omohyoideus, and m. sternohyoideus no longer substantially restrict positions of the trachea and esophagus in birds. Rather, these muscles are modified in ways which may assist with making tracheal movements. The implications of this study may provide interesting insights for future comparisons in extinct taxa.

Spatial Ecology of Estuarine Crocodile (Crocodylus porosus Nesting in a Fragmented Landscape

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Luke J. Evans

2016-09-01

Full Text Available The role that oil palm plays in the Lower Kinabatangan region of Eastern Sabah is of considerable scientific and conservation interest, providing a model habitat for many tropical regions as they become increasingly fragmented. Crocodilians, as apex predators, widely distributed throughout the tropics, are ideal indicator species for ecosystem health. Drones (or unmanned aerial vehicles (UAVs were used to identify crocodile nests in a fragmented landscape. Flights were targeted through the use of fuzzy overlay models and nests located primarily in areas indicated as suitable habitat. Nests displayed a number of similarities in terms of habitat characteristics allowing for refined modelling of survey locations. As well as being more cost-effective compared to traditional methods of nesting survey, the use of drones also enabled a larger survey area to be completed albeit with a limited number of flights. The study provides a methodology for targeted nest surveying, as well as a low-cost repeatable flight methodology. This approach has potential for widespread applicability across a range of species and for a variety of study designs.

Environmental surveillance monitoring in the Alligator Rivers Region. Report for the six months period ending 30 September 1996

International Nuclear Information System (INIS)

1996-01-01

This report outlines the activities of the Northern Territory Supervising Authorities in meeting their responsibilities for environmental management and surveillance, occupational safety, relating to uranium mining and environment protection in the Alligator Rivers Region. Environmental monitoring was carried out at the Nabarlek Mine, which site has now been rehabilitated and revegetated, and at Ranger, the only mine currently operating in the region. Other uranium projects such as Jabiluka and Koongarra have been delayed due to the former Commonwealth Government's 'three mines policy'. 4 tabs., 10 figs

Thermoregulation and temperature relations of alligators and other large ectotherms inhabiting thermally stressed habitats. Annual progress report, 1 July 1976--30 September 1977

International Nuclear Information System (INIS)

Spotila, J.R.

1977-06-01

Progress is reported on studies of the biophysical and thermal relationships between large ectotherms and their aquatic environment. Data are reported from laboratory and field studies on alligators, turtles, and fish. Mathematical models of the effect of body size and physical characteristics on temperature regulation of ectotherms and of thermal stress in aquatic organisms were developed. Results are included of field studies on the physiological and behavioral adjustments of turtles in response to changes in water temperature produced by thermal effluents in PAR Pond at the Savannah River Ecology Laboratory

A crucial role of paralogous β-defensin genes in the Chinese alligator innate immune system revealed by the first determination of a Crocodilia defensin cluster.

Science.gov (United States)

Tang, Ke-Yi; Wang, Xin; Wan, Qiu-Hong; Fang, Sheng-Guo

2018-04-01

The β-defensin, one of the antimicrobial peptides (AMPs), is a significant component of the innate immune with a broad range of antimicrobial activities. Differing from the widely-studied mammals and birds, limited information about β-defensins has been reported in reptiles, especially in crocodilians. As a same ancient species as dinosaurs and the most endangered species of 23 crocodilians, the survival of Chinese alligator (Alligator sinensis) means a powerful immune system and possible involvement of AMPs in its immune resistance. In this study, we identified 20 novel Alligator sinensisβ-defensin genes (AsBDs) from a 390 kb region using bioinformatic and experimental approaches, and successfully distinguished six orthologous AsBDs to birds and nine paralogous AsBDs undergoing gene duplication events. The amino acid alignment shows that the AsBD paralogs, like α-defensins, encode a significantly longer pro-piece comparing with the orthologs. The calculation of non-synonymous (d N ) and synonymous (d S ) substitutions in the mature peptide reveals that the AsBD paralogs experience a significantly higher selective pressure (d N /d S ) than the orthologs, but a similar evolutionary force to α-defensins. The gene expression result indicates that the AsBD paralogs have a significantly higher expression level than the orthologos in gastrointestinal tract where the host is vulnerable to enteric pathogenic bacteria, as observed in α-defensins. These three pieces of evidence demonstrate that the AsBD paralogs do play an important role in maintaining long-term survival of this endangered reptile. Thus, this survey of AsBDs on the genomic structure, evolutionary characteristics, and expression pattern provides a genetic and immunological foundation for further investigating their antimicrobial function and alternative antibiotics potentiality. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

A database of radionuclide activity and metal concentrations for the Alligator Rivers Region uranium province.

Science.gov (United States)

Doering, Che; Bollhöfer, Andreas

2016-10-01

This paper presents a database of radionuclide activity and metal concentrations for the Alligator Rivers Region (ARR) uranium province in the Australian wet-dry tropics. The database contains 5060 sample records and 57,473 concentration values. The data are for animal, plant, soil, sediment and water samples collected by the Environmental Research Institute of the Supervising Scientist (ERISS) as part of its statutory role to undertake research and monitoring into the impacts of uranium mining on the environment of the ARR. Concentration values are provided in the database for 11 radionuclides ( 227 Ac, 40 K, 210 Pb, 210 Po, 226 Ra, 228 Ra, 228 Th, 230 Th, 232 Th, 234 U, 238 U) and 26 metals (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, S, Sb, Se, Sr, Th, U, V, Zn). Potential uses of the database are discussed. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Molecular evolution and expression of archosaurian β-keratins: diversification and expansion of archosaurian β-keratins and the origin of feather β-keratins.

Science.gov (United States)

Greenwold, Matthew J; Sawyer, Roger H

2013-09-01

The archosauria consist of two living groups, crocodilians, and birds. Here we compare the structure, expression, and phylogeny of the beta (β)-keratins in two crocodilian genomes and two avian genomes to gain a better understanding of the evolutionary origin of the feather β-keratins. Unlike squamates such as the green anole with 40 β-keratins in its genome, the chicken and zebra finch genomes have over 100 β-keratin genes in their genomes, while the American alligator has 20 β-keratin genes, and the saltwater crocodile has 21 β-keratin genes. The crocodilian β-keratins are similar to those of birds and these structural proteins have a central filament domain and N- and C-termini, which contribute to the matrix material between the twisted β-sheets, which form the 2-3 nm filament. Overall the expression of alligator β-keratin genes in the integument increases during development. Phylogenetic analysis demonstrates that a crocodilian β-keratin clade forms a monophyletic group with the avian scale and feather β-keratins, suggesting that avian scale and feather β-keratins along with a subset of crocodilian β-keratins evolved from a common ancestral gene/s. Overall, our analyses support the view that the epidermal appendages of basal archosaurs used a diverse array of β-keratins, which evolved into crocodilian and avian specific clades. In birds, the scale and feather subfamilies appear to have evolved independently in the avian lineage from a subset of archosaurian claw β-keratins. The expansion of the avian specific feather β-keratin genes accompanied the diversification of birds and the evolution of feathers. Copyright © 2013 Wiley Periodicals, Inc.

Isolation and characterization of microsatellite loci for alligator gar (Atractosteus spatula) and their variability in two other species (Lepisosteus oculatus and L. osseus) of Lepisosteidae

Science.gov (United States)

Moyer, G.R.; Sloss, Brian L.; Kreiser, B.R.; Feldheim, K.A.

2009-01-01

We report on the isolation of 17 polymorphic microsatellite loci from alligator gar (Atractosteus spatula), a large-bodied species that has experienced population declines across much of its range. These loci possessed 2-19 alleles and observed heterozygosities of 0-0.974. All loci conformed to Hardy-Weinberg equilibrium expectations, and none exhibited linkage disequilibrium. Nine and eight of these loci were found to be polymorphic in the related species Lepisosteus oculatus and L. osseus, respectively. These microsatellite loci should prove useful in conservation efforts of A. spatula through the study of population structure and hatchery broodstock management. ?? 2009 Blackwell Publishing Ltd.

Reactividad inmunoquímica de sueros anti- Caiman yacare y Caiman latirostris frente a sueros de diferentes especies

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de Roodt, Adolfo Rafael

2010-06-01

reactivity was tested by double immunodiffusion and ELISA. The results showed high reactivity among the sera from crocodiles while the reactivity against sera from the other species of reptiles studied was lower. The reactivity among sera of both species of Caiman was higher with the anti- Caiman latirostris and anti-Caiman yacare sera when compared with the reactivity against serum of Alligator missisipiensis. In addition, a strong reactivity of both anti Caiman sera on serum from Gallus gallus was observed, indicating a high reactivity between achosauria sera.

A stream sediment orientation programme for Uranium in the Alligator River Province, Northern Territory, Australia

International Nuclear Information System (INIS)

Gingrich, J.E.; Foy, M.F.

1977-01-01

Sediments samples were collected from streams draining the Koongarra uranium deposit and the small uranium mines in the South Alligator Valley. Determinations for U, Cu and Pb on various size fractions taken from each of these samples indicated that the best results were obtained for U from the minus 200-mesh fraction, but the train from the Koongarra ore deposit was very short. Cu and Pb were not found to be very useful as indicator elements for U. Alpha-track films were used to determine the Rn content of each sample and the ratio of alpha-track film reading to U content was found to define anomalous drainage areas around the mineralization in the Koongarra area. The areas so defined were of sufficient magnitude to be defined in a reconnaissance stream sediment programme

Current status of Marsh Crocodiles Crocodylus palustris (Reptilia: Crocodylidae in Vishwamitri River, Vadodara City, Gujarat, India

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R. Vyas

2012-11-01

Full Text Available Data presented here is based on a three year study (2008-2010 on a population of Mugger Crocodylus palustris inhabiting Vishwamitri River near Vadodara City, Gujarat State, India. In total, 155 Muggers were counted in the 25km river stretch during 2010. In all, 40 burrows were observed along the river bank, and the same were clumped in certain sections of the river. Muggers fed eight species of birds, and domestic livestock in addition to scavenging. Eight instances of human-crocodile conflicts were observed including four human causalities. A total 90 Muggers were rescued from the urban areas and the same were relocated elsewhere in the river system. Various types of threats to Mugger were also noticed including habitat loss, alteration and soil erosion and mortality due to rail traffic. The present study suggests further research to propose strategies to conserve this population.

Development of the Alligator Rivers uranium deposits

International Nuclear Information System (INIS)

Bath, L.J.; Farthing, J.W.; Warner, R.K.

1980-01-01

The Alligator Rivers Uranium Province in the Northern Territory of Australia has proven uranium deposits at Jabiluka, Ranger, Koongarra and Nabarlek which contain more than 80% of the country's low-cost reasonably assured uranium resources estimated to be 290,000 t U. Following the Government's decision in 1977 to proceed with the further development of Australia's uranium resources, the region is destined to become a major producer of U 3 O 8 for export. At the time of the decision provision was made for strict controls to protect the environment, the granting of Aboriginal land rights and the creation of a major national park. The paper describes the progress made to achieve these objectives. The open-cut mining methods to be used at Ranger, Koongarra and Nabarlek are described, as well as the underground mining operations proposed for Jabiluka. Each of the treatment plants will use the conventional acid leach, solvent extraction purification process for uranium recovery. The characteristics of the treatment operations are outlined. The water-management schemes, tailings disposal methods and procedures for environment protection are also discussed. The proposed initial production capacities of the operations are: Jabiluka 2540 (expanding to 7630 in the fifth year of production); Ranger 2540 (expanding to 5080 when commercially practicable); Koongarra 850; and Nabarlek 920 t U/a. Both Nabarlek and Ranger have been granted Government development approval and construction is proceeding at each site with the expectation that normal commercial production will commence towards the end of 1980 and 1981, respectively. Planning for the Jabiluka and Koongarra projects has reached an advanced stage; each are undergoing environmental procedures and will have to reach agreement with the Aboriginals on environmental and other matters before site work can commence. (author)

Viruses in reptiles.

Science.gov (United States)

Ariel, Ellen

2011-09-21

The etiology of reptilian viral diseases can be attributed to a wide range of viruses occurring across different genera and families. Thirty to forty years ago, studies of viruses in reptiles focused mainly on the zoonotic potential of arboviruses in reptiles and much effort went into surveys and challenge trials of a range of reptiles with eastern and western equine encephalitis as well as Japanese encephalitis viruses. In the past decade, outbreaks of infection with West Nile virus in human populations and in farmed alligators in the USA has seen the research emphasis placed on the issue of reptiles, particularly crocodiles and alligators, being susceptible to, and reservoirs for, this serious zoonotic disease. Although there are many recognised reptilian viruses, the evidence for those being primary pathogens is relatively limited. Transmission studies establishing pathogenicity and cofactors are likewise scarce, possibly due to the relatively low commercial importance of reptiles, difficulties with the availability of animals and permits for statistically sound experiments, difficulties with housing of reptiles in an experimental setting or the inability to propagate some viruses in cell culture to sufficient titres for transmission studies. Viruses as causes of direct loss of threatened species, such as the chelonid fibropapilloma associated herpesvirus and ranaviruses in farmed and wild tortoises and turtles, have re-focused attention back to the characterisation of the viruses as well as diagnosis and pathogenesis in the host itself.

AHR and CYP1A expression link historical contamination events to modern day developmental effects in the American alligator.

Science.gov (United States)

Hale, Matthew D; Galligan, Thomas M; Rainwater, Thomas R; Moore, Brandon C; Wilkinson, Philip M; Guillette, Louis J; Parrott, Benjamin B

2017-11-01

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that initiates a transcriptional pathway responsible for the expression of CYP1A subfamily members, key to the metabolism of xenobiotic compounds. Toxic planar halogenated aromatic hydrocarbons, including dioxin and PCBs, are capable of activating the AHR, and while dioxin and PCB inputs into the environment have been dramatically curbed following strict regulatory efforts in the United States, they persist in the environment and exposures remain relevant today. Little is known regarding the effects that long-term chronic exposures to dioxin or dioxin-like compounds might have on the development and subsequent health of offspring from exposed individuals, nor is much known regarding AHR expression in reptilians. Here, we characterize AHR and CYP1A gene expression in embryonic and juvenile specimen of a long-lived, apex predator, the American alligator (Alligator mississippiensis), and investigate variation in gene expression profiles in offspring collected from sites conveying differential exposures to environmental contaminants. Both age- and tissue-dependent patterning of AHR isoform expression are detected. We characterize two downstream transcriptional targets of the AHR, CYP1A1 and CYP1A2, and describe conserved elements of their genomic architecture. When comparisons across different sites are made, hepatic expression of CYP1A2, a direct target of the AHR, appears elevated in embryos from a site associated with a dioxin point source and previously characterized PCB contamination. Elevated CYP1A2 expression is not persistent, as site-specific variation was absent in juveniles originating from field-collected eggs but reared under lab conditions. Our results illustrate the patterning of AHR gene expression in a long-lived environmental model species, and indicate a potential contemporary influence of historical contamination. This research presents a novel opportunity to link

Problems of communicating radiation doses to aboriginal members of the public in the Alligator Rivers Region

International Nuclear Information System (INIS)

McLaughlin, D.

1985-01-01

Since the early 1970s, Aboriginal people of the Alligator Rivers Region have had to come to grips with the effects of uranium mining at Nabarlek and Ranger. One element in their cost-benefit approach to mine operations has been the expectation that bush foods in the region will not be contaminated by the mining operations. Recent studies on radionuclide concentrations in freshwater mussels (Velesunio angasi) in the region have shown this species, and perhaps others, to be efficient accumulators of radium. Information concerning natural radium accumulation in mussels and accompanying health risk estimates have been conveyed to Aboriginal people of the area and such information transfer has not been without its problems. Application of the ALARA principle to environmental management of the effluent pathways needs to consider Aboriginal expectations

Organochlorine contaminants in complete clutches of Morelet's crocodile (Crocodylus moreletii) eggs from Belize

Energy Technology Data Exchange (ETDEWEB)

Wu, Ted H. [Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK 99775-6160 (United States); Canas, Jaclyn E. [Institute of Environmental and Human Health, Texas Tech University, Box 41163, Lubbock, TX 79409 (United States); Rainwater, Thomas R. [Institute of Environmental and Human Health, PO Box 764, Jefferson, TX 75657 (United States); Platt, Steven G. [Department of Math and Science, Oglala Lakota College, 490 Piya Wiconi Road, Kyle, SD, 57752 (United States); McMurry, Scott T. [Institute of Environmental and Human Health, Texas Tech University, Box 41163, Lubbock, TX 79409 (United States); Anderson, Todd A. [Institute of Environmental and Human Health, Texas Tech University, Box 41163, Lubbock, TX 79409 (United States)]. E-mail: todd.anderson@ttu.edu

2006-11-15

Seven complete clutches of Morelet's crocodile (Crocodylus moreletii) eggs were collected in northern Belize and examined for organochlorine (OC) pesticide residues. The primary OC detected, p,p-DDE, was found in every egg analyzed (n = 175). Other OCs detected included p,p-DDT, p,p-DDD, methoxychlor, aldrin, and endosulfan I. Concentrations of individual OCs ranged from 4 ppb (ng chemical/g egg wet weight) to greater than 500 ppb. A statistical evaluation of p,p-DDE levels in three complete clutches was used to derive the minimum number of eggs needed from a clutch to precisely determine the mean p,p-DDE concentration representative of that clutch. Sample sizes of 8 (80% confidence level) and 11 (90% confidence level) were determined to yield an accurate estimate of contaminant levels in a full clutch of eggs. The statistically recommended sample size of 11 eggs (at 90% confidence level) was successfully tested on the four additional clutches. -- Sampling the non-viable eggs of a clutch can provide a statistically reasonable estimation of both the organochlorine contaminant distribution and concentrations in that clutch.

Digital dissection and three-dimensional interactive models of limb musculature in the Australian estuarine crocodile (Crocodylus porosus.

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Ada J Klinkhamer

Full Text Available Digital dissection is a relatively new technique that has enabled scientists to gain a better understanding of vertebrate anatomy. It can be used to rapidly disseminate detailed, three-dimensional information in an easily accessible manner that reduces the need for destructive, traditional dissections. Here we present the results of a digital dissection on the appendicular musculature of the Australian estuarine crocodile (Crocodylus porosus. A better understanding of this until now poorly known system in C. porosus is important, not only because it will expand research into crocodilian locomotion, but because of its potential to inform muscle reconstructions in dinosaur taxa. Muscles of the forelimb and hindlimb are described and three-dimensional interactive models are included based on CT and MRI scans as well as fresh-tissue dissections. Differences in the arrangement of musculature between C. porosus and other groups within the Crocodylia were found. In the forelimb, differences are restricted to a single tendon of origin for triceps longus medialis. For the hindlimb, a reduction in the number of heads of ambiens was noted as well as changes to the location of origin and insertion for iliofibularis and gastrocnemius externus.

CHARACTERIZATION OF MORPHOLOGICAL TRAITS OF COMMERCIAL INTEREST IN THE MORELET'S CROCODILE (Crocodylus moreletii

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Ricardo Serna-Lagunes

2011-11-01

Full Text Available Crocodylus moreletii is a species of commercial interest based on its skin. In this study, five morphological traits of commercial interest were characterized in 125 captivity-raised specimens of C. moreletii from four populations (Puente Chilapa, Gutiérrez Zamora, Villa Juárez and Puerto Vallarta. A canonical discriminant analysis (CDA was used to differentiate the populations according to their morphological traits, a cluster analysis (CA was used to infer which populations had the largest total length (TL, and a covariance analysis (ANCOVA was used to assess the allometry and detect which population was different in terms of TL. The CDA showed no significant effects, suggesting that the morphological traits were similar among populations; the CA grouped two populations which had the largest body size; the ANCOVA revealed a significant correlation between morphological traits and detected a TL effect significantly lower in males and females from Puente Chilapa, in comparison with the other three populations. In conclusion, the males from Gutiérrez Zamora and the females from Villa Juárez were morphologically outstanding in terms of TL, and they would be the right crocodiles to establish a breeding nucleus in order to obtain offspring with their phenotypic characteristics.

ANÁLISE MICROBIOLÓGICA DA CARNE DE JACARÉ DO PANTANAL (Caiman crocodilus yacare MICROBIAL ANALYSIS CHARACTERISTICS OF THE ALLIGATOR'S MEAT (Caiman crocodilus yacare

Directory of Open Access Journals (Sweden)

Fernando Leite HOFFMANN

1998-08-01

Full Text Available O objetivo deste estudo foi realizar o levantamento das características microbiológicas da carne do jacaré, através da detecção e/ou enumeração dos microrganismos mais comumente encontrados na carne. Pela inexistência de padrões na legislação brasileira para a carne de jacaré, os resultados foram comparados com os padrões microbiológicos existentes para carne bovina e pescado. Encontrou-se a presença de S. aureus e de Salmonella sp, resultados estes considerados insatisfatórios, o que nos permitiu, classificar o produto como impróprio para o consumo. O trabalho sugere também, procedimentos para evitar e/ou minimizar a presença desses microrganismos indesejáveis na carne.This work subjects to collect data of the microbial characteristics of the alligator meat, and also to identify the microrganisms that can be found in it. The current Brazilian legislation does not have any specific regulations for the alligator meat, then the results were compaired to the microbial standards for the fresh beef and fish. The results has showed the presence of the S. aureus and Salmonella sp. These results let us to classify the product submited to the test, as unsatisfactory and, therefore, inadequate to the human consumption. The present study also suggests some procedures to avoid or minimize the presence of these microrganisms.

Molecular structures of centromeric heterochromatin and karyotypic evolution in the Siamese crocodile (Crocodylus siamensis) (Crocodylidae, Crocodylia).

Science.gov (United States)

Kawagoshi, Taiki; Nishida, Chizuko; Ota, Hidetoshi; Kumazawa, Yoshinori; Endo, Hideki; Matsuda, Yoichi

2008-01-01

Crocodilians have several unique karyotypic features, such as small diploid chromosome numbers (30-42) and the absence of dot-shaped microchromosomes. Of the extant crocodilian species, the Siamese crocodile (Crocodylus siamensis) has no more than 2n = 30, comprising mostly bi-armed chromosomes with large centromeric heterochromatin blocks. To investigate the molecular structures of C-heterochromatin and genomic compartmentalization in the karyotype, characterized by the disappearance of tiny microchromosomes and reduced chromosome number, we performed molecular cloning of centromeric repetitive sequences and chromosome mapping of the 18S-28S rDNA and telomeric (TTAGGG)( n ) sequences. The centromeric heterochromatin was composed mainly of two repetitive sequence families whose characteristics were quite different. Two types of GC-rich CSI-HindIII family sequences, the 305 bp CSI-HindIII-S (G+C content, 61.3%) and 424 bp CSI-HindIII-M (63.1%), were localized to the intensely PI-stained centric regions of all chromosomes, except for chromosome 2 with PI-negative heterochromatin. The 94 bp CSI-DraI (G+C content, 48.9%) was tandem-arrayed satellite DNA and localized to chromosome 2 and four pairs of small-sized chromosomes. The chromosomal size-dependent genomic compartmentalization that is supposedly unique to the Archosauromorpha was probably lost in the crocodilian lineage with the disappearance of microchromosomes followed by the homogenization of centromeric repetitive sequences between chromosomes, except for chromosome 2.

Ecological studies on the freshwater fishes of the Alligator Rivers region, Northern Territory

International Nuclear Information System (INIS)

Bishop, K.A.; Allen, S.A.; Pollard, D.A.; Cook, M.G.

1990-01-01

The tropical climate of the Alligator Rivers Region (ARR) has a distinctive wet-dry cycle , resulting in seasonal flows in the creeks and rivers of its catchments. The present study, begun in August 1978, was aimed at developing an ecological monitoring system that would detect any changes to the freshwater fish communities brought about by recent uranium mining and processing in the lowlands of the ARR. The focus of the synecological studies, was a description of spatial and temporal patterns in the community structure of the fish fauna. Interpretation of these patterns was made possible by the collection of detailed environmental data from the study sites. It was found that of the ARR seasonal changes in environmental conditions were so marked that they often obscured the effects of environmental gradients along a watercourse and differing environmental conditions characteristics of different types of waterbody. Hence it may not be entirely satisfactory to define environmental zones in these catchments based on overall environmental conditions through the whole seasonal cycle, because changes in any one such zone between seasons result in very marked changes in the fish communities of habitats in that zone. 34 refs., 22 tabs., 45 figs., 3 maps

The International intraval project. Phase 1 case 8: The Alligator rivers natural analogue

International Nuclear Information System (INIS)

Duerden, P.

1992-01-01

INTRAVAL is an international coordinated research program for predicting the potential radionuclide migration in the geosphere with the use of mathematical models. Such models are used to help assess the long-term safety of radioactive waste disposal systems. The objective of the Alligator Rivers Analogue Project (ARAP) is to identify and study long-term processes that have been significant in the development of the uranium dispersion zone at the Koongarra uranium ore deposit in the Northern Territory of Australia. This report includes a description of the site geology and gives an outline of the experimental programs, which are aimed to study the hydrogeology and geochemistry of the system, and the distribution of uranium and its daughter radionuclides in the rock strata. The extensive databases that have resulted from these studies have been used to develop and test hydrological, geochemical and transport models. A good basis has been established for modelling the transport of radionuclides in the porous, weathered zone of the Koongarra uranium deposit and its surroundings. A number of preliminary transport, hydrology and geochemical modelling reports are given, with the Koongarra databases also being used to test a Performance Assessment model. The possible application of scenario development procedures to the Koongarra site is discussed. 106 refs., 67 figs., 28 tabs

Characterization of mineral coatings associated with a Pleistocene-Holocene rock art style: The Northern Running Figures of the East Alligator River region, western Arnhem Land, Australia.

Science.gov (United States)

King, Penelope L; Troitzsch, Ulrike; Jones, Tristen

2017-02-01

This data article contains mineralogic and chemical data from mineral coatings associated with rock art from the East Alligator River region. The coatings were collected adjacent to a rock art style known as the "Northern Running Figures" for the purposes of radiocarbon dating (doi:10.1016/j.jasrep.2016.11.016; (T. Jones, V. Levchenko, P.L. King, U. Troitzsch, D. Wesley, 2017) [1]). This contribution includes raw and processed powder X-ray Diffraction data, Scanning Electron Microscopy energy dispersive spectroscopy data, and Fourier Transform infrared spectral data.

New insight into the anatomy of the hyolingual apparatus of Alligator mississippiensis and implications for reconstructing feeding in extinct archosaurs.

Science.gov (United States)

Li, Zhiheng; Clarke, Julia A

2015-07-01

Anatomical studies of the cranium of crocodilians motivated by an interest in its function in feeding largely focused on bite force, the jaw apparatus and associated muscles innervated by the trigeminal nerve. However, the ossified and cartilaginous elements of the hyoid and the associated hyolingual muscles, innervated by the facial, hypoglossal and glossopharyngeal nerves, received much less attention. Crocodilians are known to retain what are ancestrally the 'Rhythmic Hyobranchial Behaviors' such as buccal oscillation, but show diminished freedom and movement for the hyobranchial apparatus and the tongue in food transport and manipulation. Feeding among crocodilians, generally on larger prey items than other reptilian outgroups, involves passive transport of the food within the mouth. The tongue in extant crocodilians is firmly attached to the buccal floor and shows little movement during feeding. Here, we present a detailed anatomical description of the myology of the hyolingual apparatus of Alligator mississippiensis, utilizing contrast-enhanced micro-computed tomography and dissection. We construct the first three-dimensional (3D) description of hyolingual myology in Alligator mississippiensis and discuss the detailed implications of these data for our understanding of hyolingual muscle homology across Reptilia. These anatomical data and an evaluation of the fossil record of hyoid structures also shed light on the evolution of feeding in Reptilia. Simplification of the hyoid occurs early in the evolution of archosaurs. A hyoid with only one pair of ceratobranchials and a weakly ossified or cartilaginous midline basihyal is ancestral to Archosauriformes. The comparison with non-archosaurian reptilian outgroup demonstrates that loss of the second set of ceratobranchials as well as reduced ossification in basihyal occurred prior to the origin of crown-clade archosaurs, crocodilians and birds. Early modification in feeding ecology appears to characterize the

Bioactive compounds from crocodile (Crocodylus siamensis) white blood cells induced apoptotic cell death in hela cells.

Science.gov (United States)

Patathananone, Supawadee; Thammasirirak, Sompong; Daduang, Jureerut; Chung, Jing Gung; Temsiripong, Yosapong; Daduang, Sakda

2016-08-01

Crocodile (Crocodylus siamensis) white blood cell extracts (WBCex) were examined for anticancer activity in HeLa cell lines using the MTT assay. The percentage viability of HeLa cells significantly deceased after treatment with WBCex in a dose- and time-dependent manner. The IC50 dose was suggested to be approximately 225 μg/mL protein. Apoptotic cell death occurred in a time-dependent manner based on investigation by flow cytometry using annexin V-FITC and PI staining. DAPI nucleic acid staining indicated increased chromatin condensation. Caspase-3, -8 and -9 activities also increased, suggesting the induction of the caspase-dependent apoptotic pathway. Furthermore, the mitochondrial membrane potential (ΔΨm ) of HeLa cells was lost as a result of increasing levels of Bax and reduced levels of Bcl-2, Bcl-XL, Bcl-Xs, and XIAP. The decreased ΔΨm led to the release of cytochrome c and the activation of caspase-9 and -3. Apoptosis-inducing factor translocated into the nuclei, and endonuclease G (Endo G) was released from the mitochondria. These results suggest that anticancer agents in WBCex can induce apoptosis in HeLa cells via both caspase-dependent and -independent pathways. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 986-997, 2016. © 2015 Wiley Periodicals, Inc.

Population variables and life-history characteristics of the alligator pipefish Syngnathoides biaculeatus, in Papua New Guinea.

Science.gov (United States)

Barrows, A P W; Martin-Smith, K M; Baine, M S P

2009-03-01

Population structure and life-history variables of the widely distributed alligator pipefish Syngnathoides biaculeatus were characterized in Bootless Bay, Papua New Guinea over the course of 11 months. There was little evidence of seasonality with four focal populations showing no significant change in abundance. Similarly, the sex ratio remained 1:1 for all but 1 month. Reproductive males carrying eggs (148-278 mm in total length, L(T)) were found in all months. Brood size was significantly, positively related to male L(T) for newly laid broods only. Maximum observed brood size was 351 and mean +/-s.d. brood size was 238 +/- 57 for newly laid broods. Juveniles and males showed no change in mean L(T) over the year while slightly smaller females were captured in November 2006 and September 2007. Males were significantly longer than females so von Bertalanffy growth coefficients were estimated separately for each sex: males L(infinity)= 285 mm, K = 0.82 year(-1) and females L(infinity)= 261 mm, K = 1.10 year(-1). These estimates suggest that this species grows rapidly and has a short-life span. In the context of growing concern about overexploitation of syngnathids, a rapid growth rate combined with year round reproductive activity suggests that the tropical S. biaculeatus may be relatively resilient with regard to fishing pressure.

Home range utilisation and long-range movement of estuarine crocodiles during the breeding and nesting season.

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Hamish A Campbell

Full Text Available The estuarine crocodile (Crocodylus porosus is the apex-predator in waterways and coastlines throughout south-east Asia and Australasia. C. porosus pose a potential risk to humans, and management strategies are implemented to control their movement and distribution. Here we used GPS-based telemetry to accurately record geographical location of adult C. porosus during the breeding and nesting season. The purpose of the study was to assess how C. porosus movement and distribution may be influenced by localised social conditions. During breeding, the females (2.92 ± 0.013 metres total length (TL, mean ± S.E., n = 4 occupied an area<1 km length of river, but to nest they travelled up to 54 km away from the breeding area. All tagged male C. porosus sustained high rates of movement (6.49 ± 0.9 km d(-1; n = 8 during the breeding and nesting period. The orientation of the daily movements differed between individuals revealing two discontinuous behavioural strategies. Five tagged male C. porosus (4.17 ± 0.14 m TL exhibited a 'site-fidelic' strategy and moved within well-defined zones around the female home range areas. In contrast, three males (3.81 ± 0.08 m TL exhibited 'nomadic' behaviour where they travelled continually throughout hundreds of kilometres of waterway. We argue that the 'site-fidelic' males patrolled territories around the female home ranges to maximise reproductive success, whilst the 'nomadic' males were subordinate animals that were forced to range over a far greater area in search of unguarded females. We conclude that C. porosus are highly mobile animals existing within a complex social system, and mate/con-specific interactions are likely to have a profound effect upon population density and distribution, and an individual's travel potential. We recommend that impacts on socio-spatial behaviour are considered prior to the implementation of management interventions.

Why the long face? The mechanics of mandibular symphysis proportions in crocodiles.

Directory of Open Access Journals (Sweden)

Christopher W Walmsley

Full Text Available BACKGROUND: Crocodilians exhibit a spectrum of rostral shape from long snouted (longirostrine, through to short snouted (brevirostrine morphologies. The proportional length of the mandibular symphysis correlates consistently with rostral shape, forming as much as 50% of the mandible's length in longirostrine forms, but 10% in brevirostrine crocodilians. Here we analyse the structural consequences of an elongate mandibular symphysis in relation to feeding behaviours. METHODS/PRINCIPAL FINDINGS: Simple beam and high resolution Finite Element (FE models of seven species of crocodile were analysed under loads simulating biting, shaking and twisting. Using beam theory, we statistically compared multiple hypotheses of which morphological variables should control the biomechanical response. Brevi- and mesorostrine morphologies were found to consistently outperform longirostrine types when subject to equivalent biting, shaking and twisting loads. The best predictors of performance for biting and twisting loads in FE models were overall length and symphyseal length respectively; for shaking loads symphyseal length and a multivariate measurement of shape (PC1- which is strongly but not exclusively correlated with symphyseal length were equally good predictors. Linear measurements were better predictors than multivariate measurements of shape in biting and twisting loads. For both biting and shaking loads but not for twisting, simple beam models agree with best performance predictors in FE models. CONCLUSIONS/SIGNIFICANCE: Combining beam and FE modelling allows a priori hypotheses about the importance of morphological traits on biomechanics to be statistically tested. Short mandibular symphyses perform well under loads used for feeding upon large prey, but elongate symphyses incur high strains under equivalent loads, underlining the structural constraints to prey size in the longirostrine morphotype. The biomechanics of the crocodilian mandible are largely

Mining in the Alligator Rivers Region, northern Australia: Assessing potential and actual effects on ecosystem and human health

International Nuclear Information System (INIS)

Dam, R.A. van; Humphrey, C.L.; Martin, P.

2002-01-01

This paper presents an overview of issues related to surface water contamination arising from uranium mining activities in the Alligator Rivers Region (ARR) of northern Australia, and a program of research and monitoring that must assess the potential and actual effects on ecosystem and human health. The program of assessing effects on aquatic ecosystems involves a four-tiered approach including the derivation of local water quality guideline trigger values, direct toxicity assessment of mine waters prior to their release, creekside or in situ monitoring for early warning of adverse effects during mine water release, and longer-term monitoring of macroinvertebrate and fish communities. Bioaccumulation in aquatic biota is also assessed, and is an issue of importance not only to ecosystem health, but also to the health of local Aboriginal people. The aquatic animals they consume represent potential sources of radiological dose, and as a result, a major component of the program to assess potential effects on human health is the prediction of doses to Aboriginal people living downstream of mining activities. Acknowledging the assumptions and uncertainties, the calculation of concentration factors for local aquatic (and other) food sources allows the prediction of potential radiological exposure to people following hypothetical mine water releases. The approaches described form the basis of best-practice protocols that are relevant at both regional and national levels

Land application of waste waters in the Alligator Rivers region, Northern Territory - environmental constraints on design and operation

International Nuclear Information System (INIS)

Kearns, A.

1986-01-01

The existing uranium mines in the Alligator River Region presently operate under a no release water management regime for water stored within the designated restricted release zones (RRZ). This water is of variable quality ranging from rainwater influenced by runoff from the mill sites and ore stockpiles to mill process water stored within the trailings repositories. There is a pressing need to reduce the volume of stored RRZ water at Nabarlek as a prerequisite to decommissioning. There is also a requirement at Ranger to rapidly reduce the volume of stored water in the mine pit at the end of the season to allow the mining of ore. Land application of RRZ water by spray irrigation has been investigated at both sites because it offers the benefits of applying chemical constituents in the wastewater within a clearly defined irrigation area. the environmental planning for the design of a land application system involves calculations of the chemical load in the wastewater and evaluation of the assimilative capacity of the soil-plant system. The monsoon climate, lateritic soil and fluctuating water table creates a unique set of environmental constraints and conditions in which to design and operate a successful land application system for the treatment of stored water at minesites within ecologically sensitive areas

Geomorphological assessment of sites and impoundments for the long term containment of uranium mill tailings in the Alligator Rivers Region

International Nuclear Information System (INIS)

East, T.J.

1985-01-01

Current and future research into the geomorphological processes likely to affect the long term containment of uranium mill tailings in the Alligator Rivers Region is directed at three main areas: identification of geomorphic hazards at proposed impoundment sites; determination of erosion rates on impoundment slopes; and prediction of patterns of fluvial dispersal of released tailings. Each necessitates consideration of present and future geomorphic processes. Process rates during the next few thousand years might be predictable by extrapolation of contemporary and past (i.e. Holocene) climates, sea-levels and depositional environments, evidence for which is preserved in the sedimentary record. In current projects, the Late Quarternary stratigraphy of Magela Creek are examined to provide data for modelling of present and future sedimentological processes. Site stability evaluation entails recognition of present and future geomorphic hazards at impoundment sites, and includes fluvial and hillslope erosion, extreme flood events and mass movements. The life of a tailings impoundment is further determined by the intensity of erosional processes acting upon its slopes and their cover materials. A knowledge of present and future erosion rates will allow the optimisation of slope characteristics and materials in the impoundment design

Ontogeny of the Alligator Cartilago Transiliens and Its Significance for Sauropsid Jaw Muscle Evolution

Science.gov (United States)

Tsai, Henry P.; Holliday, Casey M.

2011-01-01

The cartilago transiliens is a fibrocartilaginous structure within the jaw muscles of crocodylians. The cartilago transiliens slides between the pterygoid buttress and coronoid region of the lower jaw and connects two muscles historically identified as m. pseudotemporalis superficialis and m. intramandibularis. However, the position of cartilago transiliens, and its anatomical similarities to tendon organs suggest the structure may be a sesamoid linking a single muscle. Incompressible sesamoids often form inside tendons that wrap around bone. However, such structures rarely ossify in reptiles and have thus far received scant attention. We tested the hypothesis that the cartilago transiliens is a sesamoid developed within in one muscle by investigating its structure in an ontogenetic series of Alligator mississippiensis using dissection, 3D imaging, and polarizing and standard light microscopy. In all animals studied, the cartilago transiliens receives collagen fibers and tendon insertions from its two main muscular attachments. However, whereas collagen fibers were continuous within the cartilaginous nodule of younger animals, such continuity decreased in older animals, where the fibrocartilaginous core grew to displace the fibrous region. Whereas several neighboring muscles attached to the fibrous capsule in older individuals, only two muscles had significant contributions to the structure in young animals. Our results indicate that the cartilago transiliens is likely a sesamoid formed within a single muscle (i.e., m. pseudotemporalis superficialis) as it wraps around the pterygoid buttress. This tendon organ is ubiquitous among fossil crocodyliforms indicating it is a relatively ancient, conserved structure associated with the development of the large pterygoid flanges in this clade. Finally, these findings indicate that similar tendon organs exist among potentially homologous muscle groups in birds and turtles, thus impacting inferences of jaw muscle homology

Alligator Rivers Analogue project. Hydrogeological modelling. Final Report - Volume 6

International Nuclear Information System (INIS)

Townley, L.R.; Trefry, M.G.; Barr, A.D.; Braumiller, S.

1992-01-01

This volume describes hydrogeological modelling carried out as part of the Alligator Rivers Analogue Project. Hydrogeology has played a key integrating role in the Project, largely because water movement is believed to have controlled the evolution of the Koongarra uranium Orebody and therefore affects field observations of all types at all scales. Aquifer testing described uses the concept of transmissivity in its interpretation of aquifer response to pumping. The concept of an aquifer, a layer transmitting significant quantities of water in a mainly horizontal direction, seems hard to accept in an environment as heterogeneous as that at Koongarra. But modelling of aquifers both in one dimension and two dimensionally in plan has contributed significantly to our understanding of the site. A one-dimensional model with three layers (often described as a quasi two dimensional model) was applied to flow between the Fault and Koongarra Creek. Being a transient model, this model was able to show that reverse flows can indeed occur back towards the Fault, but only if there is distributed recharge over the orebody as well as a mechanism for the Fault, or a region near the Fault, to remove water from the simulated cross-section. The model also showed clearly that the response of the three-layered system, consisting of a highly weathered zone, a fractured transmissive zone and a less conductive lower schist zone, is governed mainly by the transmissivity and storage coefficient of the middle layer. The storage coefficient of the higher layer has little effect. A two-dimensional model in plan used a description of anisotropy to show that reverse flows can also occur even without a conducting Fault. Modelling of a three-dimensional region using discrete fractures showed that it is certainly possible to simulate systems like that observed at Koongarra, but that large amounts of data are probably needed to obtain realistic descriptions of the fracture networks. Inverse modelling

Alligator Rivers Analogue project. Hydrogeological modelling. Final Report - Volume 6

Energy Technology Data Exchange (ETDEWEB)

Townley, L R; Trefry, M G; Barr, A D [CSIRO Div of Water Resources, PO Wembley, WA (Australia); Braumiller, S [Univ of Arizona, Tucson, AZ (United States). Dept of Hydrology and Water Resources; Kawanishi, M [Central Research Institute of Electric Power Industry, Abiko-Shi, Chiba-Ken (Japan); and others

1993-12-31

This volume describes hydrogeological modelling carried out as part of the Alligator Rivers Analogue Project. Hydrogeology has played a key integrating role in the Project, largely because water movement is believed to have controlled the evolution of the Koongarra uranium Orebody and therefore affects field observations of all types at all scales. Aquifer testing described uses the concept of transmissivity in its interpretation of aquifer response to pumping. The concept of an aquifer, a layer transmitting significant quantities of water in a mainly horizontal direction, seems hard to accept in an environment as heterogeneous as that at Koongarra. But modelling of aquifers both in one dimension and two dimensionally in plan has contributed significantly to our understanding of the site. A one-dimensional model with three layers (often described as a quasi two dimensional model) was applied to flow between the Fault and Koongarra Creek. Being a transient model, this model was able to show that reverse flows can indeed occur back towards the Fault, but only if there is distributed recharge over the orebody as well as a mechanism for the Fault, or a region near the Fault, to remove water from the simulated cross-section. The model also showed clearly that the response of the three-layered system, consisting of a highly weathered zone, a fractured transmissive zone and a less conductive lower schist zone, is governed mainly by the transmissivity and storage coefficient of the middle layer. The storage coefficient of the higher layer has little effect. A two-dimensional model in plan used a description of anisotropy to show that reverse flows can also occur even without a conducting Fault. Modelling of a three-dimensional region using discrete fractures showed that it is certainly possible to simulate systems like that observed at Koongarra, but that large amounts of data are probably needed to obtain realistic descriptions of the fracture networks. Inverse modelling

Thermoregulation and temperature relations of alligators and other large ectotherms inhabiting thermally stressed habitats. Progress report, 1 October 1974--30 September 1977

International Nuclear Information System (INIS)

Spotila, J.R.

1977-06-01

Significant progress has been made in determining the mechanisms by which large ectotherms adjust to thermal stress in their natural environment. The effect of mouth gaping on head temperatures and the role of radiation, conduction and convection on body temperatures of alligators have been determined. The utility of energy budget modeling as a method for studying the thermoregulatory mechanisms of animals has been demonstrated. Steady state and time dependent models of body temperature have been tested. Convection coefficients and evaporative water loss rates have been measured for the turtle, Chysemys scripta. Climate space diagrams have been formulated and are being tested. Behavioral thermoregulation of turtles has been studied in PAR pond on the Savannah River Plant, Aiken, S.C. Steady state energy budget equations have been computed for largemouth bass. Experimental heat transfer coefficients indicate that most heat transfer is through the body wall and not via the gills. A time dependent model is being tested. It predicts the body temperature of a fish in a heterothermal environment. Theoretical calculations have been made of the effects of body size, color, and metabolism on the temperature regulation of ectotherms

The Alligator rivers natural analogue - Modelling of uranium and thorium migration in the weathered zone at Koongarra

International Nuclear Information System (INIS)

Skagius, K.; Lindgren, M.; Boghammar, A.; Brandberg, F.; Pers, K.; Widen, H.

1993-08-01

The Koongarra Uranium Deposit in the Alligator Rivers Region in the Northern Territory of Australia is a natural analogue being investigated with the aim to contribute to the understanding of the scientific basis for the long term prediction of radionuclide migration within geological environments relevant to radioactive waste repositories. The dispersion of uranium and decay products in the weathered zone has been modelled with a simple advection-dispersion-reversible sorption model and with a model extended to also consider α-recoil and transfer of radionuclides between different mineral phases of the rock. The modelling work was carried out in several iterations, each including a review of available laboratory and field data, selection of the system to be modelled and suitable model, and a comparison of modelling results with field observations. Uranium concentrations in bulk rock calculated with the simple advection-dispersion- reversible sorption model were in fair agreement with observed data using parameter values within ranges recommended based on independent interpretations. The advection-dispersion-reversible sorption model is a large simplification of the system among other things because the partitioning of radionuclides between water and solid phase is described with a sorption equilibrium term only. Although the results from this study not are enough to validate simple performance assessment models in a strict sense, it has been shown that even simple models are able to describe the present day distribution of uranium in the weathered zone at Koongarra. 23 refs, 61 figs

The Alligator rivers natural analogue - Modelling of uranium and thorium migration in the weathered zone at Koongarra

Energy Technology Data Exchange (ETDEWEB)

Skagius, K; Lindgren, M; Boghammar, A; Brandberg, F; Pers, K; Widen, H [Kemakta, Stockholm (Sweden)

1993-08-01

The Koongarra Uranium Deposit in the Alligator Rivers Region in the Northern Territory of Australia is a natural analogue being investigated with the aim to contribute to the understanding of the scientific basis for the long term prediction of radionuclide migration within geological environments relevant to radioactive waste repositories. The dispersion of uranium and decay products in the weathered zone has been modelled with a simple advection-dispersion-reversible sorption model and with a model extended to also consider {alpha}-recoil and transfer of radionuclides between different mineral phases of the rock. The modelling work was carried out in several iterations, each including a review of available laboratory and field data, selection of the system to be modelled and suitable model, and a comparison of modelling results with field observations. Uranium concentrations in bulk rock calculated with the simple advection-dispersion- reversible sorption model were in fair agreement with observed data using parameter values within ranges recommended based on independent interpretations. The advection-dispersion-reversible sorption model is a large simplification of the system among other things because the partitioning of radionuclides between water and solid phase is described with a sorption equilibrium term only. Although the results from this study not are enough to validate simple performance assessment models in a strict sense, it has been shown that even simple models are able to describe the present day distribution of uranium in the weathered zone at Koongarra. 23 refs, 61 figs.

Role of Chromosome Changes in Evolution and Diversity

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Kornsorn Srikulnath

2015-12-01

Full Text Available The karyotypes of most species of crocodilians were studied using conventional and molecular cytogenetics. These provided an important contribution of chromosomal rearrangements for the evolutionary processes of Crocodylia and Sauropsida (birds and reptiles. The karyotypic features of crocodilians contain small diploid chromosome numbers (30~42, with little interspecific variation of the chromosome arm number (fundamental number among crocodiles (56~60. This suggested that centric fusion and/or fission events occurred in the lineage, leading to crocodilian evolution and diversity. The chromosome numbers of Alligator, Caiman, Melanosuchus, Paleosuchus, Gavialis, Tomistoma, Mecistops, and Osteolaemus were stable within each genus, whereas those of Crocodylus (crocodylians varied within the taxa. This agreed with molecular phylogeny that suggested a highly recent radiation of Crocodylus species. Karyotype analysis also suggests the direction of molecular phylogenetic placement among Crocodylus species and their migration from the Indo-Pacific to Africa and The New World. Crocodylus species originated from an ancestor in the Indo-Pacific around 9~16 million years ago (MYA in the mid-Miocene, with a rapid radiation and dispersion into Africa 8~12 MYA. This was followed by a trans-Atlantic dispersion to the New World between 4~8 MYA in the Pliocene. The chromosomes provided a better understanding of crocodilian evolution and diversity, which will be useful for further study of the genome evolution in Crocodylia.

Should I stay or should I go? Dispersal and population structure in small, isolated desert populations of West African crocodiles.

Directory of Open Access Journals (Sweden)

Guillermo Velo-Antón

Full Text Available The maintenance of both spatial and genetic connectivity is paramount to the long-term persistence of small, isolated populations living in environments with extreme climates. We aim to identify the distribution of genetic diversity and assess population sub-structuring and dispersal across dwarfed desert populations of Crocodylus suchus, which occur in isolated groups, usually less than five individuals, along the mountains of Mauritania (West Africa. We used both invasive and non-invasive sampling methods and a combination of mitochondrial DNA (12 S and ND4 and microsatellite markers (32 loci and a subset of 12 loci. Our results showed high genetic differentiation and geographic structure in Mauritanian populations of C. suchus. We identified a metapopulation system acting within four river sub-basins (high gene flow and absence of genetic structure and considerable genetic differentiation between sub-basins (FST range: 0.12-0.24 with rare dispersal events. Effective population sizes tend to be low within sub-basins while genetic diversity is maintained. Our study suggests that hydrographic networks (temporal connections along seasonal rivers during rainy periods allow C. suchus to disperse and maintain metapopulation dynamics within sub-basins, which attenuate the loss of genetic diversity and the risk of extinction. We highlight the need of hydrographic conservation to protect vulnerable crocodiles isolated in small water bodies. We propose C. suchus as an umbrella species in Mauritania based on ecological affinities shared with other water-dependent species in desert environments.

Evolution of the α2-adrenoreceptors in vertebrates: ADRA2D is absent in mammals and crocodiles.

Science.gov (United States)

Céspedes, Héctor A; Zavala, Kattina; Vandewege, Michael W; Opazo, Juan C

2017-09-01

Evolutionary studies of genes that have been functionally characterized and whose variation has been associated with pathological conditions represent an opportunity to understand the genetic basis of pathologies. α 2 -Adrenoreceptors (ADRA2) are a class of G protein-coupled receptors that regulate several physiological processes including blood pressure, platelet aggregation, insulin secretion, lipolysis, and neurotransmitter release. This gene family has been extensively studied from a molecular/physiological perspective, yet much less is known about its evolutionary history. Accordingly, the goal of this study was to investigate the evolutionary history of α 2 -adrenoreceptors (ADRA2) in vertebrates. Our results show that in addition to the three well-recognized α 2 -adrenoreceptor genes (ADRA2A, ADRA2B and ADRA2C), we recovered a clade that corresponds to the fourth member of the α 2 -adrenoreceptor gene family (ADRA2D). We also recovered a clade that possesses two ADRA2 sequences found in two lamprey species. Furthermore, our results show that mammals and crocodiles are characterized by possessing three α 2 -adrenoreceptor genes, whereas all other vertebrate groups possess the full repertoire of α 2 -adrenoreceptor genes. Among vertebrates ADRA2D seems to be a dispensable gene, as it was lost two independent times during the evolutionary history of the group. Additionally, we found that most examined species possess the most common alleles described for humans; however, there are cases in which non-human mammals possess the alternative variant. Finally, transcript abundance profiles revealed that during the early evolutionary history of gnathostomes, the expression of ADRA2D in different taxonomic groups became specialized to different tissues, but in the ancestor of sarcopterygians this specialization would have been lost. Copyright © 2017 Elsevier Inc. All rights reserved.

Completion of the South Alligator Valley remediation, Northern Territory, Australia - -16198

International Nuclear Information System (INIS)

Waggitt, Peter; Fawcett, Mike

2009-01-01

13 uranium mines operated in the South Alligator Valley of Australia's Northern Territory between 1953 and 1963. At the end of operations the mines, and associated infrastructure, were simply abandoned. As this activity preceded environmental legislation by about 15 years there was neither any obligation, nor attempt, at remediation. In the 1980's it was decided that the whole area should become an extension of the adjacent World Heritage, Kakadu National Park. As a result the Commonwealth Government made an inventory of the abandoned mines and associated facilities in 1986. This established the size and scope of the liability and formed the framework for a possible future remediation project. The initial program for the reduction of physical and radiological hazards at each of the identified sites was formulated in 1989 and the works took place from 1990 to 1992. But even at this time, as throughout much of the valley's history, little attention was being paid to the long term aspirations of traditional land owners. The traditional Aboriginal owners, the Gunlom Land Trust, were granted freehold Native Title to the area in 1996. They immediately leased the land back to the Commonwealth Government so it would remain a part of Kakadu National Park, but under joint management. One condition of the lease required that all evidence of former mining activity be remediated by 2015. The consultation, and subsequent planning processes, for a final remediation program began in 1997. A plan was agreed in 2003 and, after funding was granted in 2005, works implementation commenced in 2007. An earlier paper described the planning and consultation stages, experience involving the cleaning up of remnant uranium mill tailings and other mining residues; and the successful implementation of the initial remediation works. This paper deals with the final planning and design processes to complete the remediation programme, which is due to occur in 2009. The issues of final containment

Alligator Rivers Analogue project. Hydrogeological field studies. Final Report - Volume 5

Energy Technology Data Exchange (ETDEWEB)

Davis, S N [Univ of Arizona, Tucson, Arizona (United States). Dept of Hydrology and Water Resources; Marley, R D [D.B. Stephens and Associates Inc., Albuquerque, NM (United States); Norris, J R [Hydro Geo Chem Inc., Tucson, Arizona (United States)

1993-12-31

The hydrogeology of the Koongarra site was interpreted primarily from long-term hydrographs, water-level maps, water injection tests, aquifer pumping tests, logs of boreholes, and chemical analyses of groundwater samples. Data have been collected over a 21-year period starting with test-drilling in 1970. The first intensive period of hydrogeologic investigations was from 1978 through 1981 and was related to anticipated exploitation of uranium ore at Koongarra. The second period was from 1986 through 1991 and was related to the international Alligator Rivers Analogue Project under the direction of the Australian Nuclear Science and Technology Organisation. The conclusion which can be drawn from the chemical data is that water moving out of the No. 1 ore deposit is diluted rapidly with recharge from the surface as it migrates down the hydraulic gradient. Most of the groundwater outside of the ore deposit does not originate from the ore deposit, and flow models which assume unmodified stream tubes extending out of the ore deposit in a downgradient direction do not reflect the true system. Water in the ore deposit itself, must come from slow upward seepage through the fault zone. Owing to the fact that this water must be at least hundreds of years old, observed fluctuations of water levels in the deposit must reflect pressure head variations induced by seasonal recharge to the overlying surficial materials. Water level fluctuations do not signify a yearly displacement of water deep in the system. Water in the deeper part of the ore must be almost static compared to obvious rapid groundwater circulation in the area around PH88. Small changes in pH, temperature and specific electrical conductivity during aquifer tests indicate a complex hydraulic system which has a variable response to pumping as a function of time. Low concentration in tritium and Carbon-14 together with high concentrations of dissolved helium in the groundwaters all suggested strongly that semi static

Alligator Rivers Analogue project. Hydrogeological field studies. Final Report - Volume 5

Energy Technology Data Exchange (ETDEWEB)

Davis, S.N. [Univ of Arizona, Tucson, Arizona (United States). Dept of Hydrology and Water Resources; Marley, R.D. [D.B. Stephens and Associates Inc., Albuquerque, NM (United States); Norris, J.R. [Hydro Geo Chem Inc., Tucson, Arizona (United States)

1992-12-31

The hydrogeology of the Koongarra site was interpreted primarily from long-term hydrographs, water-level maps, water injection tests, aquifer pumping tests, logs of boreholes, and chemical analyses of groundwater samples. Data have been collected over a 21-year period starting with test-drilling in 1970. The first intensive period of hydrogeologic investigations was from 1978 through 1981 and was related to anticipated exploitation of uranium ore at Koongarra. The second period was from 1986 through 1991 and was related to the international Alligator Rivers Analogue Project under the direction of the Australian Nuclear Science and Technology Organisation. The conclusion which can be drawn from the chemical data is that water moving out of the No. 1 ore deposit is diluted rapidly with recharge from the surface as it migrates down the hydraulic gradient. Most of the groundwater outside of the ore deposit does not originate from the ore deposit, and flow models which assume unmodified stream tubes extending out of the ore deposit in a downgradient direction do not reflect the true system. Water in the ore deposit itself, must come from slow upward seepage through the fault zone. Owing to the fact that this water must be at least hundreds of years old, observed fluctuations of water levels in the deposit must reflect pressure head variations induced by seasonal recharge to the overlying surficial materials. Water level fluctuations do not signify a yearly displacement of water deep in the system. Water in the deeper part of the ore must be almost static compared to obvious rapid groundwater circulation in the area around PH88. Small changes in pH, temperature and specific electrical conductivity during aquifer tests indicate a complex hydraulic system which has a variable response to pumping as a function of time. Low concentration in tritium and Carbon-14 together with high concentrations of dissolved helium in the groundwaters all suggested strongly that semi static

Viruses in reptiles

Directory of Open Access Journals (Sweden)

Ariel Ellen

2011-09-01

Full Text Available Abstract The etiology of reptilian viral diseases can be attributed to a wide range of viruses occurring across different genera and families. Thirty to forty years ago, studies of viruses in reptiles focused mainly on the zoonotic potential of arboviruses in reptiles and much effort went into surveys and challenge trials of a range of reptiles with eastern and western equine encephalitis as well as Japanese encephalitis viruses. In the past decade, outbreaks of infection with West Nile virus in human populations and in farmed alligators in the USA has seen the research emphasis placed on the issue of reptiles, particularly crocodiles and alligators, being susceptible to, and reservoirs for, this serious zoonotic disease. Although there are many recognised reptilian viruses, the evidence for those being primary pathogens is relatively limited. Transmission studies establishing pathogenicity and cofactors are likewise scarce, possibly due to the relatively low commercial importance of reptiles, difficulties with the availability of animals and permits for statistically sound experiments, difficulties with housing of reptiles in an experimental setting or the inability to propagate some viruses in cell culture to sufficient titres for transmission studies. Viruses as causes of direct loss of threatened species, such as the chelonid fibropapilloma associated herpesvirus and ranaviruses in farmed and wild tortoises and turtles, have re-focused attention back to the characterisation of the viruses as well as diagnosis and pathogenesis in the host itself. 1. Introduction 2. Methods for working with reptilian viruses 3. Reptilian viruses described by virus families 3.1. Herpesviridae 3.2. Iridoviridae 3.2.1 Ranavirus 3.2.2 Erythrocytic virus 3.2.3 Iridovirus 3.3. Poxviridae 3.4. Adenoviridae 3.5. Papillomaviridae 3.6. Parvoviridae 3.7. Reoviridae 3.8. Retroviridae and inclusion body disease of Boid snakes 3.9. Arboviruses 3.9.1. Flaviviridae 3

Estudo do aproveitamento das vísceras do jacaré do pantanal (Caiman crocodilus yacare em farinha de carne Study of the utilization of the pantanal alligator's viscera for meat flour

Directory of Open Access Journals (Sweden)

Pedro Fernando Romanelli

2003-12-01

Full Text Available O presente trabalho teve por objetivo a produção de farinha de carne a partir das vísceras do jacaré do pantanal (Caiman crocodilus yacare e o estudo das propriedades físico-químicas, bioquímicas e bacteriológicas da farinha elaborada. Essas características que servem de parâmetro de controle de qualidade, são normalmente exigidas na comercialização de farinhas de carne elaboradas a partir de vísceras e outros materiais de descarte para animais de consumo doméstico. Os resultados obtidos do pH, acidez solúvel, composição percentual dos componentes, dos minerais Ca e P, digestibilidade em pepsina, aspecto microbiológico (presença de "salmonela" e estabilidade avaliada pelo nº de TBARS da farinha mostram ser viável o uso das vísceras do jacaré do pantanal como fonte alternativa de nutrientes para incorporação nas formulações de ração animal .The present paper shidied study the production of the meat flour from the pantanal alligator's viscera as well as the physic-chemical, biochemical and microbiological proprieties of the obtained flour. These proprieties can be parameters of quality control and are normally demanded in the trade of meat flour made from viscera and other discharge animals for domestic use.The results obtained from pH, soluble acidity, components percentual composition, Ca and P minerals, digestibility in pepsin, the microbiological aspect (salmonella determination, and the stability to the meat flour according to the evaluation of the number of TBARS, demonstrate the use of the viscera of the pantanal alligator are feasible as alternate source of nutrients for the incorporation in the formulating of animal feed.

Binding of tryptophan and iron by reptilion plasnna proteins

African Journals Online (AJOL)

transport functions. Albumin of the alligator (Alligator mississippiensis) and other reptiles binds, amongst other ions, tryptophan (McMenamy & Watson 1968) and transferrin binds iron (Barber & Sheeler 1963). Multiple transferrins are present in the plasma of many reptiles. (Dessauer et af 1962) and the albumin region of the.

Using the American alligator and a repeated-measures design to place constraints on in vivo shoulder joint range of motion in dinosaurs and other fossil archosaurs.

Science.gov (United States)

Hutson, Joel D; Hutson, Kelda N

2013-01-15

Using the extant phylogenetic bracket of dinosaurs (crocodylians and birds), recent work has reported that elbow joint range of motion (ROM) studies of fossil dinosaur forearms may be providing conservative underestimates of fully fleshed in vivo ROM. As humeral ROM occupies a more central role in forelimb movements, the placement of quantitative constraints on shoulder joint ROM could improve fossil reconstructions. Here, we investigated whether soft tissues affect the more mobile shoulder joint in the same manner in which they affect elbow joint ROM in an extant archosaur. This test involved separately and repeatedly measuring humeral ROM in Alligator mississippiensis as soft tissues were dissected away in stages to bare bone. Our data show that the ROMs of humeral flexion and extension, as well as abduction and adduction, both show a statistically significant increase as flesh is removed, but then decrease when the bones must be physically articulated and moved until they separate from one another and/or visible joint surfaces. A similar ROM pattern is inferred for humeral pronation and supination. All final skeletonized ROMs were less than initial fully fleshed ROMs. These results are consistent with previously reported elbow joint ROM patterns from the extant phylogenetic bracket of dinosaurs. Thus, studies that avoid separation of complementary articular surfaces may be providing fossil shoulder joint ROMs that underestimate in vivo ROM in dinosaurs, as well as other fossil archosaurs.

Extensive homology of chicken macrochromosomes in the karyotypes of Trachemys scripta elegans and Crocodylus niloticus revealed by chromosome painting despite long divergence times.

Science.gov (United States)

Kasai, F; O'Brien, P C M; Martin, S; Ferguson-Smith, M A

2012-01-01

We report extensive chromosome homology revealed by chromosome painting between chicken (Gallus gallus domesticus, GGA, 2n = 78) macrochromosomes (representing 70% of the chicken genome) and the chromosomes of a turtle, the red-eared slider (Trachemys scripta elegans, TSC, 2n = 50), and the Nile crocodile (Crocodylus niloticus, CNI, 2n = 32). Our data show that GGA1-8 arms seem to be conserved in the arms of TSC chromosomes, GGA1-2 arms are separated and homologous to CNI1p, 3q, 4q and 5q. In addition to GGAZ homologues in our previous study, large-scale GGA autosome syntenies have been conserved in turtle and crocodile despite hundreds of millions of years divergence time. Based on phylogenetic hypotheses that crocodiles diverged after the divergence of birds and turtles, our results in CNI suggest that GGA1-2 and TSC1-2 represent the ancestral state and that chromosome fissions followed by fusions have been the mechanisms responsible for the reduction of chromosome number in crocodiles. Copyright © 2012 S. Karger AG, Basel.

Sedimentation of the basal Kombolgie Formation (Upper Precambrian-Carpentarian) Northern Territory, Australia: possible significance in the genesis of the underlying Alligator Rivers unconformity-type uranium deposits

International Nuclear Information System (INIS)

Ojakangas, R.W.

1979-10-01

The 1400 to 1500 My old Kombolgie Formation of the MacArthur Basin of the Northern Territory overlies or has overlain unconformity-type uranium deposits including Jabiluka, Ranger, Koongarra, Nabarlek and the small deposits of the South Alligator River Valley. A brief study of the basal portion of the formation showed it to consist entirely of mature conglomerates and quartzose sandstones. Analysis of the bedding types (planar cross beds, trough cross beds and parallel beds) and other sedimentary structures (mainly ripple marks and parting lineation) fit a braided alluvial plain model. A paleocurrent study utilizing about 400 measurements from nine localities located along the westward-facing 250 kilometer-long erosional escarpment of the Arnhem Land Plateau showed the dominant paleocurrent trend to be from west and northwest towards the east and southeast, with local divergence. The data and interpretation presented are relevant to the supergene model of uranium deposition at the unconformity, for they add to the suggestion that additional uranium deposits similar to Jabiluka Two may underlie the Kombolgie Formation eastward from the present escarpment

Final Environmental Impact Statement Evolved Expendable Launch Vehicle Program

Science.gov (United States)

1998-04-01

including increased blood pressure and higher levels of available glucose and corticosteroids in the bloodstream. Continued disturbances and prolonged...treefrogs. Besides the common American alligator , reptiles observed include the Florida box turtle, the gopher tortoise, the Florida softshell, the...star Remirea maritima - E Reptiles and Amphibians Gopher frog Rana capito C SSC American alligator Alligator mississippiensis T(S/A) SSC Eastern Indigo

Radionuclide migration around uranium ore bodies in the Alligator Rivers region of the Northern Territory, Australia - analogue of radioactive waste repositories

International Nuclear Information System (INIS)

Airey, P.L.; Roman, D.; Golian, C.; Short, S.; Nightingale, T.; Lowson, R.T.; Davey, B.G.; Gray, D.

1984-01-01

Appropriate geochemical analogues may be used to reduce the uncertainties in predicting the long-term transport of actinides, radium and fission products from laboratory adsorption and hydrological data. In this study the migration of uranium series nuclides within, and down-gradient of ore bodies in the Alligator Rivers uranium province of the Northern Territory of Australia is described. A mathematical framework was developed to permit calculation of the rate of leaching or deposition of uranium and radium between defined zones of the ore bodies, and the rate of loss of the nuclides due to groundwater transport and surface erosion. A detailed study was made of the distribution of uranium, thorium and radium isotopes within various minerals comprising the weathered ore assemblage. Uranium and thorium concentrate principally in the iron minerals and radium in the clay-quartz phases. Substantial disequilibria are observed, which are attributed to a combination of α-recoil and chemical effects. Evidence of the relative lability of iron phases is presented. The transport of uranium series nuclides in groundwater intersecting the deposits was investigated. Down-gradient of the Ranger One deposit, the maximum retardation factor of uranium is 250. The role of colloids in groundwater transport is being studied. Uranium is transported principally in solution. There appears to be an equilibrium between solute and articulate uranium

Revised stratigraphic nomenclature and correlation of early proterozoic rocks of the Darwin - Katherine region, Northern Territory

International Nuclear Information System (INIS)

Needham, R.S.; Stuart-Smith, P.G.

1984-01-01

New stratigraphic names and correlations are given for parts of the Early Proterozoic Pine Creek Geosyncline metasedimentary sequence and overlying felsic volcanics of the Darwin-Katherine region. They have significant implications for the stratigraphic distribution of uranium mineralisation in the Rum Jungle, Alligator Rivers and South Alligator Valley uranium fields

Factors affecting individual foraging specialization and temporal diet stability across the range of a large "generalist" apex predator.

Science.gov (United States)

Rosenblatt, Adam E; Nifong, James C; Heithaus, Michael R; Mazzotti, Frank J; Cherkiss, Michael S; Jeffery, Brian M; Elsey, Ruth M; Decker, Rachel A; Silliman, Brian R; Guillette, Louis J; Lowers, Russell H; Larson, Justin C

2015-05-01

Individual niche specialization (INS) is increasingly recognized as an important component of ecological and evolutionary dynamics. However, most studies that have investigated INS have focused on the effects of niche width and inter- and intraspecific competition on INS in small-bodied species for short time periods, with less attention paid to INS in large-bodied reptilian predators and the effects of available prey types on INS. We investigated the prevalence, causes, and consequences of INS in foraging behaviors across different populations of American alligators (Alligator mississippiensis), the dominant aquatic apex predator across the southeast US, using stomach contents and stable isotopes. Gut contents revealed that, over the short term, although alligator populations occupied wide ranges of the INS spectrum, general patterns were apparent. Alligator populations inhabiting lakes exhibited lower INS than coastal populations, likely driven by variation in habitat type and available prey types. Stable isotopes revealed that over longer time spans alligators exhibited remarkably consistent use of variable mixtures of carbon pools (e.g., marine and freshwater food webs). We conclude that INS in large-bodied reptilian predator populations is likely affected by variation in available prey types and habitat heterogeneity, and that INS should be incorporated into management strategies to efficiently meet intended goals. Also, ecological models, which typically do not consider behavioral variability, should include INS to increase model realism and applicability.

Factors affecting individual foraging specialization and temporal diet stability across the range of a large “generalist” apex predator

Science.gov (United States)

Rosenblatt, Adam E.; Nifong, James C.; Heithaus, Michael R.; Mazzotti, Frank J.; Cherkiss, Michael S.; Jeffery, Brian M.; Elsey, Ruth M.; Decker, Rachel A.; Silliman, Brian R.; Guillette, Louis J.; Lowers, Russell H.; Larson, Justin C.

2015-01-01

Individual niche specialization (INS) is increasingly recognized as an important component of ecological and evolutionary dynamics. However, most studies that have investigated INS have focused on the effects of niche width and inter- and intraspecific competition on INS in small-bodied species for short time periods, with less attention paid to INS in large-bodied reptilian predators and the effects of available prey types on INS. We investigated the prevalence, causes, and consequences of INS in foraging behaviors across different populations of American alligators (Alligator mississippiensis), the dominant aquatic apex predator across the southeast US, using stomach contents and stable isotopes. Gut contents revealed that, over the short term, although alligator populations occupied wide ranges of the INS spectrum, general patterns were apparent. Alligator populations inhabiting lakes exhibited lower INS than coastal populations, likely driven by variation in habitat type and available prey types. Stable isotopes revealed that over longer time spans alligators exhibited remarkably consistent use of variable mixtures of carbon pools (e.g., marine and freshwater food webs). We conclude that INS in large-bodied reptilian predator populations is likely affected by variation in available prey types and habitat heterogeneity, and that INS should be incorporated into management strategies to efficiently meet intended goals. Also, ecological models, which typically do not consider behavioral variability, should include INS to increase model realism and applicability.

Multimodeling: new approaches for linking ecological models

Science.gov (United States)

Gross, Louis J.; DeAngelis, Donald L.; Scott, J. Michael; Heglund, Patricia J.; Morrison, Michael L.

2006-01-01

The Everglades region of South Florida presents one of the major natural system management challenges facing the United States. With its assortment of alligators, crocodiles, manatees, panthers, large mixed flocks of wading birds, highly diverse subtropical flora, and sea of sawgrass, the ecosystem is unique in this country (Davis and Ogden 1994). The region is also perhaps the largest human-controlled system on the planet in that the major environmental factor influencing the region is water, and water flows are managed on a daily basis--subject to the vagaries of rainfall--by a massive system of locks, pumps, canals, and levees constructed over the past century. The changes brought about by such control have led to extensive modifications of historical patterns and magnitudes of flow, causing large declines in many native species, extensive changes in nutrient cycling and vegetation across south Florida, and great increases in pollutants such as mercury. Constrained by the conflicting demands of agriculture, urban human populations, and wildlife for control of water resources, and the varying agendas of hosts of government agencies and nongovernmental organizations, there is now an ongoing effort to plan for major changes to the system with expenditure estimates of eight billion dollars or more over the next several decades (USACOE 1999). Carrying out such planning, particularly as it impacts the natural systems of the region, provides one of the major challenges to the new field of computational ecology.

Microbiology of Animal Bite Wound Infections

Science.gov (United States)

Abrahamian, Fredrick M.; Goldstein, Ellie J. C.

2011-01-01

Summary: The microbiology of animal bite wound infections in humans is often polymicrobial, with a broad mixture of aerobic and anaerobic microorganisms. Bacteria recovered from infected bite wounds are most often reflective of the oral flora of the biting animal, which can also be influenced by the microbiome of their ingested prey and other foods. Bacteria may also originate from the victim's own skin or the physical environment at the time of injury. Our review has focused on bite wound infections in humans from dogs, cats, and a variety of other animals such as monkeys, bears, pigs, ferrets, horses, sheep, Tasmanian devils, snakes, Komodo dragons, monitor lizards, iguanas, alligators/crocodiles, rats, guinea pigs, hamsters, prairie dogs, swans, and sharks. The medical literature in this area has been made up mostly of small case series or case reports. Very few studies have been systematic and are often limited to dog or cat bite injuries. Limitations of studies include a lack of established or inconsistent criteria for an infected wound and a failure to utilize optimal techniques in pathogen isolation, especially for anaerobic organisms. There is also a lack of an understanding of the pathogenic significance of all cultured organisms. Gathering information and conducting research in a more systematic and methodical fashion through an organized research network, including zoos, veterinary practices, and rural clinics and hospitals, are needed to better define the microbiology of animal bite wound infections in humans. PMID:21482724

Anaphylactic reactions to novel foods

DEFF Research Database (Denmark)

Ballardini, Natalia; Nopp, Anna; Hamsten, Carl

2017-01-01

sequence homology to chicken a-parvalbumin, as the main cross-reactive allergen. We conclude that crocodile meat can be a potent food allergen and patients with allergy to chicken meat should be advised to avoid intake of meat from crocodile species. Both foods and people travel around the world......Availability of "exotic" foods is steadily increasing. In this report, we describe the first case of anaphylaxis to crocodile meat. The patient was a 13-year-old boy with severe immunoglobulin E-mediated allergy to chicken meat. When tasting crocodile meat for the first time, he developed...... and accessibility to exotic foods is steadily growing. As a result, novel allergic cross-reactivities are likely to become a challenge in the management of food allergy and, as our report illustrates, cross-reactivity has to be considered even between foods that might not intuitively be perceived as related....

Presence of Breeding Birds Improves Body Condition for a Crocodilian Nest Protector.

Science.gov (United States)

Nell, Lucas A; Frederick, Peter C; Mazzotti, Frank J; Vliet, Kent A; Brandt, Laura A

2016-01-01

Ecological associations where one species enhances habitat for another nearby species (facilitations) shape fundamental community dynamics and can promote niche expansion, thereby influencing how and where species persist and coexist. For the many breeding birds facing high nest-predation pressure, enemy-free space can be gained by nesting near more formidable animals for physical protection. While the benefits to protected species seem well documented, very few studies have explored whether and how protector species are affected by nest protection associations. Long-legged wading birds (Pelecaniformes and Ciconiiformes) actively choose nesting sites above resident American alligators (Alligator mississippiensis), apparently to take advantage of the protection from mammalian nest predators that alligator presence offers. Previous research has shown that wading bird nesting colonies could provide substantial food for alligators in the form of dropped chicks. We compared alligator body condition in similar habitat with and without wading bird nesting colonies present. Alligator morphometric body condition indices were significantly higher in colony than in non-colony locations, an effect that was statistically independent of a range of environmental variables. Since colonially nesting birds and crocodilians co-occur in many tropical and subtropical wetlands, our results highlight a potentially widespread keystone process between two ecologically important species-groups. These findings suggest the interaction is highly beneficial for both groups of actors, and illustrate how selective pressures may have acted to form and reinforce a strongly positive ecological interaction.

Presence of Breeding Birds Improves Body Condition for a Crocodilian Nest Protector

Science.gov (United States)

Nell, Lucas A.; Frederick, Peter C.; Mazzotti, Frank J.; Vliet, Kent A.; Brandt, Laura A.

2016-01-01

Ecological associations where one species enhances habitat for another nearby species (facilitations) shape fundamental community dynamics and can promote niche expansion, thereby influencing how and where species persist and coexist. For the many breeding birds facing high nest-predation pressure, enemy-free space can be gained by nesting near more formidable animals for physical protection. While the benefits to protected species seem well documented, very few studies have explored whether and how protector species are affected by nest protection associations. Long-legged wading birds (Pelecaniformes and Ciconiiformes) actively choose nesting sites above resident American alligators (Alligator mississippiensis), apparently to take advantage of the protection from mammalian nest predators that alligator presence offers. Previous research has shown that wading bird nesting colonies could provide substantial food for alligators in the form of dropped chicks. We compared alligator body condition in similar habitat with and without wading bird nesting colonies present. Alligator morphometric body condition indices were significantly higher in colony than in non-colony locations, an effect that was statistically independent of a range of environmental variables. Since colonially nesting birds and crocodilians co-occur in many tropical and subtropical wetlands, our results highlight a potentially widespread keystone process between two ecologically important species-groups. These findings suggest the interaction is highly beneficial for both groups of actors, and illustrate how selective pressures may have acted to form and reinforce a strongly positive ecological interaction. PMID:26934602

Multidisciplinary study of radionuclides and heavy-metal concentrations in wildlife on phosphate-mined and reclaimed lands. Final report

International Nuclear Information System (INIS)

Pritchard, P.C.H.; Bloodwell, J.M.

1986-11-01

The phosphate-rich mineral deposits of central Florida tend to exhibit background radiation levels that are elevated due to the uranium and its decay products found in association with the ore. The report documents radioactivity levels in two groups of animals that had heretofore not been examined by other investigators -- aquatic reptiles (American alligators, softshell turtles, and Florida cooter turtles) and terrestrial mammals (armadillos), based on the criterion that these species have significant proportions of their mass comprised of bony tissue likely to show elevated concentrations of radium. The alligator bones contained only low concentrations of radium, and there were no significant differences between alligators collected from mined, mineralized-unmined, or unmineralized land. Whether the levels of radium in the bones of the turtles represents a hazard to the health of these long-lived animals or to humans who may consume their flesh is unclear

Teknologi penyamakan kulit kras buaya

Directory of Open Access Journals (Sweden)

Bambang Oetojo

1992-08-01

Full Text Available The objective of this research is to know the influence of basic chromium tanning agent used to the colour and softness of the crust leather. In the carrying out it was used 12 pieces green salted cured crocodile skin of 11 up to 14 inch width. All of the crocodile skins were than pre-tanned with basic chromium tanning agent varying from 0.5%.; 1.0% and 1.5%. Each treatment needed two pieces of crocodile skin and was done twice. They were than tanned with 30% Irgatan LV. The Crust leather out put from the research was visual investigated for the Colour and the softness. Statistical analysis paints out that there is extremely signify difference (P < 0.01 the influence of the use of basic chromium tanning agent to the coulor and the softnees of the crusts leather. Practical meaning of this research is that to tan crocodile skin to be crust leather it is used 1.0 % basic chromium tanning agent 30% Irgatan LV.

Extremely high major histocompatibility complex class IIb gene ...

Indian Academy of Sciences (India)

tial for the genetic management of the captive alligator; thus much research on this ..... protected; at the same time, we must strengthen the education about alligator ... Province, Zoology Practical Skills Training Center in Fuyang. Teachers ...

Avaliação físico química da carne de jacaré-do-pantanal (Caiman yacare Daudin 1802 de idades diferentes Physichist chymistry evaluation of swampland alligator meat (Caiman yacare Daudin 1802 of different ages

Directory of Open Access Journals (Sweden)

João Vicente Neto

2007-10-01

Full Text Available Com o objetivo de avaliar a composição química e física da carne de jacaré-do-pantanal (Caiman yacare Daudin 1802, de idades diferentes, foram coletadas amostras de dois cortes de 10 jacarés-do-pantanal, sendo: 05 animais 14 meses e 05 animais com 26 meses, criados em cativeiro. Os cortes utilizados foram filé da cauda e filé do dorso. Foram determinados na composição química: umidade, proteína, extrato etéreo e cinzas; e na composição física: perda de peso por cozimento (PPC e força de cisalhamento (FC. Houve interação (PWith the objective of evaluating the chemical and physical composition of swampland alligator meat (Caiman yacare Daudin 1802, of different ages, samples of two courts of 10 swampland alligator were collected, being: 05 animals 14 months and 05 animals with 26 months, servants in captivity. The used courts were of tail and neck. They were certain in the chemical composition: moisture, protein, ethereal extract and ashes; and in the physical composition: weight loss for cooking (WLC and break force (BF. There was interaction (P<0.05 for moisture and for break force (BF. The animals with 14 months presented average of higher moisture (76.75% in the tail that the animals with 26 months (74.48%. The averages of ethereal extract varied of: 0.40% to 0.54% among the courts for the animals of 14 months and of 0.51% to 0.84% for the animals of 26 months. The found protein values were: 23.57% in the tail and 24.37% in the neck in the animals of 14 months; and of 24.26% in the tail and 23.74% in the neck for the animals of 26 months. The medium value of WLC, in the animals with 14 months was larger (40.02%, that in the animals of 26 months (33.82%. The animals abated with age of 14 months presented softer meat and values of ethereal extract smaller the animals abated with 26 months, demonstrating for these parameters a better physical and chemical quality.

African Journal of Biotechnology - Vol 7, No 17 (2008)

African Journals Online (AJOL)

Assesment of the water quality and prevalence of water borne diseases in Amassoma, Niger Delta, Nigeria · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT ... Eggshell membranes as a noninvasive sampling for molecular studies of Chinese alligators (Alligator sinensis) · EMAIL FREE FULL TEXT EMAIL FREE FULL ...

KOMPOSISI UKURAN, NISBAH KELAMIN DAN DAERAH PENYEBARAN HIU BUAYA (Pseudocarcharias kamoharai YANG TERTANGKAP DI SAMUDERA HINDIA

Directory of Open Access Journals (Sweden)

Dian Novianto

2016-05-01

Full Text Available Ikan hiu buaya (Pseudocarcharias kamoharai merupakan salah satu jenis hiu yang tertangkap secara tidak sengaja pada perikanan rawai tuna (tuna longline. Ikan hiu buaya dalam penanganannya selalu dibuang di laut karena ukuran tubuhnya yang kecil dan tidak memiliki pasar diantara ikan non target (by-catch lainnya. Penelitian tentang komposisi ukuran, nisbah kelamin dan daerah penyebaran hiu buaya dilakukan pada tahun 2010 – 2011 di perairan WPP 573 – 572 Samudera Hindia dengan mengikuti kapal longline yang berbasis di Benoa dan Bungus. Tujuan penelitian adalah untuk mendapatkan data dan informasi dalam rangka pengelolaan dan konservasi hiu buaya. Hiu buaya memiliki kisaran panjang tubuh 37 – 96 cm FL dengan panjang maksimal 96 cm FL untuk jenis betina dan 94 cm FL untuk jenis jantan dan modus pada kisaran 85 – 89 cm FL untuk jenis betina dan 75 – 79 cm FL untuk jenis jantan. Perbandingan jenis kelamin ikan jantan dan betina adalah 1 : 1,33, menunjukkan bahwa rasio ikan jantan dan betina tidak seimbang. Ikan hiu buaya terdistribusi tidak merata, hanya terdapat di 77 posisi setting pada 1120 – 1220 Bujur Timur dan 090 – 150 Lintang Selatan dari 256 jumlah setting selama periode penelitian ini.   Crocodile shark (Pseudocarcharias kamoharai is one of sharks species caught accidentally in tuna longline fisheries. Crocodile shark handling is always discarded at sea because of it is small size and is not economics value among others non-target fish (by-catch. Research on the biology of crocodile shark was conducted in 2010 – 2011 at Fisheries management Areas (FMA 572 (Indian Ocean – west Sumatera and 573 (South of Java – East Nusa Tenggara following longline vessels based in Benoa and Bungus. The purpose of research was to investigate data and information on the crocodile shark for management and conservation purposes. Crocodile shark has a range of body length of 37-96 cm FL with a maximum length of 96 cm FL for females and 94 cm

76 FR 23649 - Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition and Proposed Rule...

Science.gov (United States)

2011-04-27

... intermittent freshwater bodies, such as flooded savannahs, and occasionally observed in brackish coastal... Morelet's crocodile at fast-flowing streams such as Silk Grass Creek. While this specimen could have been...

Final Environmental Assessment for Long-Term Vegetation Control for Eglin Air Force Base, Florida

Science.gov (United States)

2008-07-14

domingensis Florida Black Bear Ursus americanus floridanus Phragmites Phragmites australis American Alligator Alligator mississippiensis White Cedar...Cont’d) Tulip Poplar Liriodendron tulipifera Indigo Snake Drymarchon corais Sweet Bay Magnolia Magnolia virginiana American Beaver Castor canadensis Red...Bay Persea borbonia Parula Warbler Parula americana Wetland and Riparian Ecological Association (Saltwater) Black Needle Rush Juncus roemerianus

Test Area C-80 Complex Final Range Environmental Assessment, Revision 1

Science.gov (United States)

2009-08-14

to intense noise might contribute to the development and aggravation of stress -related conditions such as high blood pressure, coronary disease...produced by test and training missions and their associated expendables. Noise may directly inconvenience and/or stress humans and some wildlife...Sherman’s fox squirrel Sciuris niger shermani Phragmites Phragmites australis American alligator Alligator mississippiensis White cedar Chamaecyparis

Occurrence and Intensity of Anisakid Nematode Larvae in Some Commercially Important Fish Species in Persian Gulf

Directory of Open Access Journals (Sweden)

Maryam DADAR

2016-10-01

Full Text Available Background: Anisakid nematodes are common parasites of fish, mammals, fish-eating birds, and reptiles with a worldwide distribution, causing diseases in human, fish and important economic losses.Methods: A preliminary epidemiological study was carried out on Anisakid nematodes larvae in some commercially important fish species to evaluate the anisakid nematode larvae from greater lizardfish, (Saurida tumbil, Japanese thread fin bream (Nemipterus japonicus, crocodile longtom (Tylosurus crocodilus crocodiles and longfin trevally (Carangoides armatus from the Persian Gulf of Iran.Result: The collected larvae were identified mainly as the third larval stage (L3 of Hysterothylacium larval type A, B and C, Anisakis sp., Raphidascaris sp., Pseudoterranova sp. and Philometra sp. (Nematoda: Philometridae. The prevalence of Anisakid larvae infection of examined fishes was 97.2% in N. japonicus, 90.3% in S. tumbil, 20.5% in crocodile longtom and 5.5% in longfin trevally. Anisakis type III for the first time was different from Anisakis type I and Anisakis type II.Discussion: Zoonotic anisakids by high prevalence in edible fish could be a health hazard for people. So health practices should be considered in these areas.

Multiple taxon multiple locality approach to providing oxygen isotope evidence for warm-blooded theropod dinosaurs

Science.gov (United States)

Fricke, Henry C.; Rogers, Raymond R.

2000-09-01

Oxygen isotope ratios of fossil remains of coexisting taxa from several different localities can be used to help investigate dinosaur thermoregulation. Focusing on the Late Cretaceous, oxygen isotope ratios of crocodile tooth enamel from four separate localities exhibit less of a decrease with latitude than do ratios of tooth enamel from coexisting theropod dinosaurs. A shallower latitudinal gradient for crocodiles is consistent with how oxygen isotope ratios should vary for heterothermic animals having body temperatures coupled with their environments (“cold blooded”), while a steeper gradient for theropods is consistent with how these ratios should vary for homeothermic animals having constant body temperatures independent of their environments (“warm blooded”). This inferred homoethermy in theropods is likely due to higher rates of metabolic heat production relative to crocodiles and is not an artifact of body size.

The Use of Virtual Media Laboratory to Increase Students’ Motivation on Direct Current Circuits Materials at Class X of MAN I Pekanbaru

Directory of Open Access Journals (Sweden)

Emhadelima Emhadelima

2015-12-01

Full Text Available The purpose of the study is to determine whether there is a significance effect on the use of Practicum methods by using Crocodile Program combined with lectures, question and answer activities give significant effect on  students’ activities in learning electricity simple lesson and to identify whether the use of the simulation lab provides better results than the traditional lab on learning outcomes. 36 natural science students was involved in the study. The data was analyzed by using t-test. The finding showed that the use of Practicum methods by using Crocodile Program combined with lectures; question and answer activities give significant effect on students’ activities in learning electricity simple lesson. The finding also showed that the use of the simulation lab can provide better results than the traditional lab on learning outcomes. It occurred when there is an adequate software capability and students can operate the software properly. Without taking into account about the cost of procurement of computers and software programs Crocodile, lab simulations are very low cost because it does not need to purchase laboratory equipment, supplies and other consumables. It is expected that Crocodile Program not only as a practical method to implement but also as a medium to explain the concepts of electronic circuits. Key words: Virtual Media, Circuits Materials.Copyright © 2015 by Al-Ta'lim All right reserved

Joint Essential Tasks and a Framework for Evaluation

National Research Council Canada - National Science Library

Kingston, Gina; Johns, Kevin

2002-01-01

...) to support the planning and evaluation of exercises. This process has been very successful and has seen ASJETs incorporated into the planning for the next major Australian-led exercise -- Crocodile 03...

Final Environmental Assessment for Jacksonville Aviation Authority Launch Site Operator License at Cecil Field, Florida

Science.gov (United States)

2009-07-01

lungs and reacts with hemoglobin to reduce the oxygen carrying capacity of the blood . At low concentrations, CO has been shown to aggravate the...caretta T T American Alligator Alligator mississippiensis Not Listed SSC Florida Pine Snake Pituophis melanoleucus mugitus Not Listed SSC Gopher...cause stress on the local school system or the existing City of Jacksonville infrastructure. However, it is unlikely that 50 new employees would

Desomorphine goes "crocodile".

Science.gov (United States)

Gahr, Maximilian; Freudenmann, Roland W; Hiemke, Christoph; Gunst, Ingo M; Connemann, Bernhard J; Schönfeldt-Lecuona, Carlos

2012-01-01

A systematic review was conducted to identify the available data for the term Krokodil, which is a jargon expression for an allegedly new drug. Krokodil seems to be a mixture of several substances and was first used in Russia in 2003, with a tremendous increase in the number of addicted individuals since then. The psychoactive core agent of Krokodil is desomorphine, an opioid-analogon that can be manufactured by boiling tablets containing codeine and other ingredients. The procedure results in a suspension that is used intravenously and regularly causes complications such as abscess, thrombophlebitis, and gangrene.

Ecología poblacional de Crocodylus acutus en los sistemas estuarinos de San Blas, Nayarit, México Population ecology of Crocodylus acutus in the estuarine systems of San Blas, Nayarit, Mexico

Directory of Open Access Journals (Sweden)

Helios Hernández-Hurtado

2011-09-01

Full Text Available El presente estudio se realizó en los meses de junio 2005 y febrero 2006 (estiaje, y en octubre 2005 y octubre 2007 (lluvias, en los esteros de San Blas. El objetivo fue caracterizar la población de cocodrilos a partir de su distribución y abundancia, El método utilizado consistió en recorridos nocturnos en los esteros, para contabilizar el número de individuos por kilómetro. Se realizaron 6 transectos recorriendo un total de 89 kilómetros. Los transectos A, B y C presentaron una densidad que osciló entre 2.68 y 4.31 ind/km o 0.05 ind/ha con 26 nidos activos, 6 tipos de vegetación y salinidad de 11.03‰ en estiaje a 4.92‰ en lluvias. Los transectos D, E y F presentaron una densidad que osciló entre 0.014 y 0.36 ind/km o 0.002 ind/ha, sin nidos, 1 tipo de vegetación y salinidad qosciló de 35.85‰ en estiaje a 24.56‰ en lluvias. Se obtuvo la similitud estadística en A, B y C= 80%, D y E= 70% y en F= 10% respecto a los demás. La población estimada fue de 333 cocodrilos, registrando todas las clases-talla, donde el hábitat disponible presenta las características necesarias para que Crocodylus acutus realice su ciclo biológico.This study was conducted in San Blas estuaries during June 2005 and February 2006 (dry season and October 2005 and October 2007 (rainy season. The purpose was to describe the population of crocodiles according to its distribution and abundance. Spotlight surveys counting animals found per kilometer were done navigating 89 kilometers in 6 transects. Transects A, B and C had a density from 2.68 to 4.31 crocodiles/kilometer or 0.05 crocodiles/ha, with 26 active nests, 6 different types of vegetation and salinity from 11.03‰ in dry season to 4.92‰ in rainy season. Transects D, E and F had a density from 0.014 to 0.36 crocodiles/km or 0.002 crocodiles/ha, any nest was found, 1 single type of vegetation and salinity from 35.85‰ in dry season to 24.56‰ in rainy season. Statistical similarity in

COPROLITES FROM THE DANIAN LIMESTONE (LOWER PALEOCENE) OF FAXE QUARRY, DENMARK

DEFF Research Database (Denmark)

Milàn, Jesper

2010-01-01

are attributed to sharks, and large, cylindrical coprolites with longitudinal striations on the surface are identified as crocodile coprolites. Fish and sharks are known from abundant finds of otoliths and teeth in Faxe Quarry, and crocodiles are known from finds of single bones and teeth.......A collection of coprolites found in the Danian (Lower Paleocene) limestone of Faxe Quarry, Denmark, is described and attributed to the respective producers. Small, drop-like specimens with weak signs of spiral coiling are attributed to fish. Larger, heteropolar, spirally-coiled specimens...

A repeated-measures analysis of the effects of soft tissues on wrist range of motion in the extant phylogenetic bracket of dinosaurs: Implications for the functional origins of an automatic wrist folding mechanism in Crocodilia.

Science.gov (United States)

Hutson, Joel David; Hutson, Kelda Nadine

2014-07-01

A recent study hypothesized that avian-like wrist folding in quadrupedal dinosaurs could have aided their distinctive style of locomotion with semi-pronated and therefore medially facing palms. However, soft tissues that automatically guide avian wrist folding rarely fossilize, and automatic wrist folding of unknown function in extant crocodilians has not been used to test this hypothesis. Therefore, an investigation of the relative contributions of soft tissues to wrist range of motion (ROM) in the extant phylogenetic bracket of dinosaurs, and the quadrupedal function of crocodilian wrist folding, could inform these questions. Here, we repeatedly measured wrist ROM in degrees through fully fleshed, skinned, minus muscles/tendons, minus ligaments, and skeletonized stages in the American alligator Alligator mississippiensis and the ostrich Struthio camelus. The effects of dissection treatment and observer were statistically significant for alligator wrist folding and ostrich wrist flexion, but not ostrich wrist folding. Final skeletonized wrist folding ROM was higher than (ostrich) or equivalent to (alligator) initial fully fleshed ROM, while final ROM was lower than initial ROM for ostrich wrist flexion. These findings suggest that, unlike the hinge/ball and socket-type elbow and shoulder joints in these archosaurs, ROM within gliding/planar diarthrotic joints is more restricted to the extent of articular surfaces. The alligator data indicate that the crocodilian wrist mechanism functions to automatically lock their semi-pronated palms into a rigid column, which supports the hypothesis that this palmar orientation necessitated soft tissue stiffening mechanisms in certain dinosaurs, although ROM-restricted articulations argue against the presence of an extensive automatic mechanism. Anat Rec, 297:1228-1249, 2014. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

Best Practices for Construction and Repair of Bridge Approaches and Departures

Science.gov (United States)

2018-03-01

Florida Department of Transportation (FDOT) has experienced frequent distresses in bridge approach/departure asphalt pavements in its highway system. Commonly observed distresses include alligator cracking and rutting, which reduce roadway smoothness...

South African red data book - Reptiles and Amphibians

CSIR Research Space (South Africa)

Mclachlan, GR

1978-02-01

Full Text Available Data sheets are provided for 46 threatened South African reptiles and amphibians, two being endangered (leatherback turtle, geometric tortoise) ten vulnerable (loggerhead turtle, Nile crocodile, veld monitor, water monitor, giant girdled lizard...

Sensitivity of Coastal Environments and Wildlife to Spilled Oil: South Florida: REPTILES (Reptile Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for sea turtles, crocodiles, mangrove terrapins, and other rare species in [for] South Florida. Vector...

Caracterização do processo de rigor mortis do músculo Ilio-ischiocaudalis de jacaré-do-pantanal (Caiman crocodilus yacare e maciez da carne Characterization of rigor mortis process of muscle Ilio-ischiocaudalis of pantanal alligator (Caiman crocodilus yacare and meat tenderness

Directory of Open Access Journals (Sweden)

Juliana Paulino Vieira

2012-03-01

Full Text Available Este trabalho utilizou seis carcaças de jacaré-do-pantanal (Caiman crocodilus yacare com o objetivo de caracterizar o processo de rigor mortis do músculo Ílio-ischiocaudalis durante o resfriamento industrial e avaliar a maciez dessa carne. Os jacarés foram escolhidos aleatoriamente e abatidos na Cooperativa de Criadores do Jacaré do Pantanal (COOCRIJAPAN, Cáceres, Mato Grosso. Após a sangria, aferiu-se as variações das temperaturas da câmara de resfriamento, das carcaças e o pH. Foram colhidas amostras para determinação do comprimento de sarcômero, da força de cisalhamento e perdas por cozimento em diferentes intervalos de tempo (0,5, 3, 5, 7, 10, 12, 15, 24 e 36h. A temperatura da câmara de resfriamento variou de 2,6°C (0,5h a 0,9°C (36h e a temperatura média das carcaças variou de 21,0°C a 4,2°C, respectivamente. O pH médio inicial do músculo foi de 6,7 e o final 5,6 e a contração máxima do sarcômero do músculo Ilio-ischiocaudalis ocorreu na 15ª hora após a sangria (1,5µm. Essa carne apresentou força de cisalhamento menor que 6,0kg.This paper studied six pantanal alligators (Caiman crocodilus yacare carcass with goal of rigor mortis process characterization of Ilio-ischiocaudalis muscle during industrial cooling and meat tenderness. The alligators were randomly assembled and slaughtered at Cooperativa de Criadores do Jacaré do Pantanal (COOCRIJAPAN - Cáceres- Mato Grosso After exsanguination, were mensured temperature of chilling room and carcasses, pH and samples were collected for determination the sarcomere length, shear force and cooking loss at different times (0.5, 3, 5, 7, 10, 12, 15, 24 and 36 hours. The temperature of chilling room varied from 2.6°C (0.5h to 0.9°C (36h and the mean carcass temperature from 21.0°C to 4.2°C, respectively. The mean initial pH of the muscle was 6.7 and the final was 5.6. The smallest sarcomere size ocurred at 15 hours after exsanguination (1.5µm. This meat presents

Australian uranium - the environmental issues

International Nuclear Information System (INIS)

Saddler, H.

1980-01-01

The principal theme of this paper is the changing pattern of issues which have dominated the environmental debate over uranium mining in Australia. These issues include the safeguards policy, a domestic energy policy, nuclear waste, economic development, particular environmental problems of the Alligator Rivers region and the social impact of uranium mining on the Aborigines. The special administrative arrangements which the Government has established for environmental protection in the Alligator Rivers region are outlined

MORFOLOGICAL AND HISTOCHEMICAL OBSERVATIONS ON THE SALIVARY GLANDS OF THE ALLIGATOR Caiman latirostris OBSERVAÇÕES MORFOLÓGICAS E HISTOQUÍMICAS SOBRE AS GLÂNDULAS SALIVARES DO JACARÉ Caiman latirostris (Crocodilia Reptilia

Directory of Open Access Journals (Sweden)

Gilson Herbert de Faria

2007-09-01

Full Text Available

Using histological and histochemical methods for glicoconjugates, the present work on the salivary glands of the alligator Caiman latirostris (Crocodilia Reptilia, was developed. On the bases of the results obtained, the authors believe that those glands are not well developed, appearing as unicellular structures goblet-like cells, in the stratified squamous epithelium of the oral cavity. Scattered glands alveolus without excretory tubules which extend directly with the epitelium were also present. By means of histochemical methods for glicoconjugates, it was possible to detect the glicoprotein and the sialic acid in the glandular formation of these animals.

Empregando-se métodos histológicos e histoquímicos para glicoconjugados, desenvolveu-se um trabalho sobre glândulas salivares do jacaré Caiman latirostris. Com base nos resultados obtidos, constatou-se que estas glândulas são pouco desenvolvidas, aparecendo como estruturas unicelulares, semelhantes às células caliciformes, incluídas no epitélio estratificado pavimentoso da cavidade oral. Observou-se, ainda, a presença de esparsos alvéolos glandulares desprovidos de ductos excretores que continuam diretamente com o epitélio. Por meio de métodos histoquímicos para glicoconjugados, foi possível a detecção de glicoproteína e de ácido siálico nas formações glandulares desses animais.

Cartilaginous epiphyses in extant archosaurs and their implications for reconstructing limb function in dinosaurs.

Directory of Open Access Journals (Sweden)

Casey M Holliday

2010-09-01

Full Text Available Extinct archosaurs, including many non-avian dinosaurs, exhibit relatively simply shaped condylar regions in their appendicular bones, suggesting potentially large amounts of unpreserved epiphyseal (articular cartilage. This "lost anatomy" is often underappreciated such that the ends of bones are typically considered to be the joint surfaces, potentially having a major impact on functional interpretation. Extant alligators and birds were used to establish an objective basis for inferences about cartilaginous articular structures in such extinct archosaur clades as non-avian dinosaurs. Limb elements of alligators, ostriches, and other birds were dissected, disarticulated, and defleshed. Lengths and condylar shapes of elements with intact epiphyses were measured. Limbs were subsequently completely skeletonized and the measurements repeated. Removal of cartilaginous condylar regions resulted in statistically significant changes in element length and condylar breadth. Moreover, there was marked loss of those cartilaginous structures responsible for joint architecture and congruence. Compared to alligators, birds showed less dramatic, but still significant changes. Condylar morphologies of dinosaur limb bones suggest that most non-coelurosaurian clades possessed large cartilaginous epiphyses that relied on the maintenance of vascular channels that are otherwise eliminated early in ontogeny in smaller-bodied tetrapods. A sensitivity analysis using cartilage correction factors (CCFs obtained from extant taxa indicates that whereas the presence of cartilaginous epiphyses only moderately increases estimates of dinosaur height and speed, it has important implications for our ability to infer joint morphology, posture, and the complicated functional movements in the limbs of many extinct archosaurs. Evidence suggests that the sizes of sauropod epiphyseal cartilages surpassed those of alligators, which account for at least 10% of hindlimb length. These data

Cartilaginous epiphyses in extant archosaurs and their implications for reconstructing limb function in dinosaurs.

Science.gov (United States)

Holliday, Casey M; Ridgely, Ryan C; Sedlmayr, Jayc C; Witmer, Lawrence M

2010-09-30

Extinct archosaurs, including many non-avian dinosaurs, exhibit relatively simply shaped condylar regions in their appendicular bones, suggesting potentially large amounts of unpreserved epiphyseal (articular) cartilage. This "lost anatomy" is often underappreciated such that the ends of bones are typically considered to be the joint surfaces, potentially having a major impact on functional interpretation. Extant alligators and birds were used to establish an objective basis for inferences about cartilaginous articular structures in such extinct archosaur clades as non-avian dinosaurs. Limb elements of alligators, ostriches, and other birds were dissected, disarticulated, and defleshed. Lengths and condylar shapes of elements with intact epiphyses were measured. Limbs were subsequently completely skeletonized and the measurements repeated. Removal of cartilaginous condylar regions resulted in statistically significant changes in element length and condylar breadth. Moreover, there was marked loss of those cartilaginous structures responsible for joint architecture and congruence. Compared to alligators, birds showed less dramatic, but still significant changes. Condylar morphologies of dinosaur limb bones suggest that most non-coelurosaurian clades possessed large cartilaginous epiphyses that relied on the maintenance of vascular channels that are otherwise eliminated early in ontogeny in smaller-bodied tetrapods. A sensitivity analysis using cartilage correction factors (CCFs) obtained from extant taxa indicates that whereas the presence of cartilaginous epiphyses only moderately increases estimates of dinosaur height and speed, it has important implications for our ability to infer joint morphology, posture, and the complicated functional movements in the limbs of many extinct archosaurs. Evidence suggests that the sizes of sauropod epiphyseal cartilages surpassed those of alligators, which account for at least 10% of hindlimb length. These data suggest that

Status populasi buaya Crocolylus porosus di daerah Kaimana dan Teluk Arguni Irian Jaya

Directory of Open Access Journals (Sweden)

Hellen Kurniyati

1999-06-01

Full Text Available The people of Indonesua have historically used crocodiles for a variety of non-commercial purposes. In the past ten years, a commercial collection from the wild almost threatened the population status. As pressure on the commercial hunting continuous, the successful conservation of Indonesian crocodiles will depend on the constant monitoring in the wild. Irian Jaya is one of several islands in Indonesia which historically accommodate unknown number of commercial crocodiles such as Crocolylus porosus. Althorough monitoring on the C. porosus status in Barusam Gasawi, Buruai Garawa, Kamabu rivers, and Suwiki lake located in Kaimana and Arguni Bay, Irian Jaya had been conducted since 1990 and continued in 1991, 1992, 1993, 1994, 1996, and 1998. The surveys techniques were conducted night count method and guided by a 1 : 100.000 map and GPS. A statistical analysis was performed on SAS using proc regression and proc mean. A significant result has only been noted in Suwiki Lake, where was the magnitude of the mean trend in density was 109%.

Acompanhamento das alterações post-mortem (Glicólise no músculo do jacaré do pantanal (Caiman crocodilus yacare Post-mortem alterations (Glycolysis of pantanal alligator's (Caiman crocodilus yacare muscle

Directory of Open Access Journals (Sweden)

Sebastião Roberto Taboga

2003-04-01

Full Text Available Realizaram-se avaliações químicas, histológicas e medidas de pH ao longo do tempo da degradação do glicogênio no músculo longissumus dorsi do jacaré. A metabolização do glicogênio muscular durou em torno de 50 horas, situando-se o pH muscular inicial entre 6,6 e 6,7 e estabilizando-se, depois de 36 a 48 horas, em torno de 5,5-5,6. Oitenta a 85% do glicogênio inicial foi metabolizado nas primeiras 20-25 horas pós-abate. Histologicamente o teste do PAS revelou, ao longo do tempo de armazenamento refrigerado, um decréscimo dos grânulos de glicogênio.This paper presents a study of glycogen degradation in longissimus dorsi muscle of pantanal alligator. Glycogen concentration and muscle pH measurements were assessed. Glycolysis took about 50 hours to complete. Initial muscle pH value were in the limits of 6.6 and 6.7 and after 36 hours they dropped to 5.5-5.6. On the first 20-25 hours postmortem 80-85% of inicial glycogen was metabolized. Through histologycal PAS test it was observed during cold storage a decrease on the number of glycogen granules. On the first 20-25 hours postmortem 80-85% of inicial glycogen was metabolized.

Coronary blood flow in the anesthetized American alligator (Alligator mississippiensis)

NARCIS (Netherlands)

Jensen, Bjarke; Elfwing, Magnus; Elsey, Ruth M.; Wang, Tobias; Crossley, Dane A.

2016-01-01

Coronary circulation of the heart evolved early within ectothermic vertebrates and became of vital importance to cardiac performance in some teleost fish, mammals and birds. In contrast, the role and function of the coronary circulation in ectothermic reptiles remains largely unknown. Here, we

Waste management and environmental controls in the Australian uranium mining industry

International Nuclear Information System (INIS)

Walker, D.G.; Morison, I.W.

1982-01-01

The development of the waste management and related environmental controls applied to uranium mining and processing in Australia is described. Major uranium deposits occur in the Alligator Rivers Region of the Northern Territory, a world heritage tropical wetland area with deep significance to Aboriginal people. The formulation of environmental controls took into consideration the unique features of the region in addition to experiences from earlier uranium mining operations. A description is given of the operations at Rum Jungle, the pollutants released and their effects on the environment. Commonwealth and State responsibilities for waste management and environmental control and the establishment of Codes of Practice are noted and proposed water management and tailings management programs at the four Alligator Rivers sites are described

Environmental and Cultural Resources within the Trinity River Basin

Science.gov (United States)

1971-01-01

during each conversion from one organism to another. Only the green plants are capable of manufacturing food (carbohydrates, fats, and proteins ). All...Abstract: Report of the first mammal discovered in the Early Cretaceous of the New World. Associated with turtles, crocodiles, dinosaurs , pterosaurs

Description of electrophoretic loci and tissue specific gene ...

African Journals Online (AJOL)

1994-02-09

Feb 9, 1994 ... alligators (Dessauer & Densmore 1983), lizards of the Xan- tusiidae (Bezy ..... expressed in red blood cells, and Esa-5 in brain (Harris &. Hopkinson ... catalyses the conversion of glucose to gluconic acid (Harris &. Hopkinson ...

Personnel and Vehicle Data Collection at Aberdeen Proving Ground (APG) and its Distribution for Research

Science.gov (United States)

2015-10-01

28 Magnetometer Applied Physics Model 1540-digital 3-axis fluxgate 5 Amplifiers Alligator Technologies USBPGF-S1 programmable instrumentation...Acoustic, Seismic, magnetic, footstep, vehicle, magnetometer , geophone, unattended ground sensor (UGS) 16. SECURITY CLASSIFICATION OF: 17. LIMITATION

A comparative study of piscine defense: The scales of Arapaima gigas, Latimeria chalumnae and Atractosteus spatula.

Science.gov (United States)

Sherman, Vincent R; Quan, Haocheng; Yang, Wen; Ritchie, Robert O; Meyers, Marc A

2017-09-01

We compare the characteristics of the armored scales of three large fish, namely the Arapaima gigas (arapaima), Latimeria chalumnae (coelacanth), and Atractosteus spatula (alligator gar), with specific focus on their unique structure-mechanical property relationships and their specialized ability to provide protection from predatory pressures, with the ultimate goal of providing bio-inspiration for manmade materials. The arapaima has flexible and overlapping cycloid scales which consist of a tough Bouligand-type arrangement of collagen layers in the base and a hard external mineralized surface, protecting it from piranha, a predator with extremely sharp teeth. The coelacanth has overlapping elasmoid scales that consist of adjacent Bouligand-type pairs, forming a double-twisted Bouligand-type structure. The collagenous layers are connected by collagen fibril struts which significantly contribute to the energy dissipation, so that the scales have the capability to defend from predators such as sharks. The alligator gar has inflexible articulating ganoid scales made of a hard and highly mineralized enamel-like outer surface and a tough dentine-like bony base, which resist powerful bite forces of self-predation and attack by alligators. The structural differences between the three scales correspond with the attack of their predators, and show refined mechanisms which may be imitated and incorporated into superior bioinspired and biomimetic designs that are specialized to resist specific modes of predation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification and phylogenetic analysis of a bacterium isolated from ...

African Journals Online (AJOL)

STORAGESEVER

2008-07-04

Jul 4, 2008 ... 2Anhui Research Center for Reproduction of Chinese alligator, Xuancheng, 242000, ... Before releasing, health screening protocols on individuals are very necessary. ... can be used in systems classification study of different.

Effect of Combined Intake of Garcinia Kola and Ascorbic Acid on ...

African Journals Online (AJOL)

Proximate and nutritional composition of kola nut, garcinia kola and alligator pepper. African Journal ... primarily carried bound to albumin in the blood and only a minor amount is ... increased oxida ve stress. With regular intake, the ascorbic ...

Paleoecology of the Niland Tongue

Energy Technology Data Exchange (ETDEWEB)

Robbins, E.I.

1987-01-01

The swamp or paludal ecosystem is preserved in coals and carbonaceous shales. Remains of organisms of the swamp communities consist of bacteria and fungi; algae; invertebrates such as pelecypods, gastropods, ostracodes, and insects; vertebrates such as a hard-shelled turtle and crocodiles; and vascular plant remains. Aquatic communities are found in dark shale and are represented by the remains of bacteria and fungi; algae; invertebrates such as pelecypods, gastropods, and insects; and vertebrates such as crocodiles, fish, and a soft-shelled turtle. No vascular macrophytes (rooted aquatic vegetation) could be identified in the pollen and spore assemblage. Charophytes are abundant and show that colonies of the aquatic alga lived on the lake bottoms. The great variety of organisms suggests that the environment had a high input of nutrients. The phosphate-rich Phosphoria Formation, which could serve as a good source of nutrients, cropped out in the watershed of the Niland Tongue basin. The ostracode-crocodile association, calcareous charophytes, and good preservation of plant tissues and palynomorphs put limits on the alkaline geochemical environment in which the lacustrine rocks were deposited. The palynomorphs in the Niland Tongue rocks are dark yellow and light brown in color. These colors suggest that rocks containing them have been buried deeper in the past than they are today.

NEWS AND COMMENTS

African Journals Online (AJOL)

campbell

On the morning of 13 May 2013, driving on the S28, a gravel road in southern. Kruger National Park, between Crocodile Bridge camp and Lower Sabie camp, a sub-adult Egyptian Vulture was spotted. It was in open knob-thorn - marula woodland and sitting near a white-backed vulture. The Egyptian Vulture was preening, ...

Antibodies to West Nile virus in asymptomatic mammals, birds, and reptiles in the Yucatan Peninsula of Mexico.

Science.gov (United States)

Farfán-Ale, José A; Blitvich, Bradley J; Marlenee, Nicole L; Loroño-Pino, María A; Puerto-Manzano, Fernando; García-Rejón, Julián E; Rosado-Paredes, Elsy P; Flores-Flores, Luis F; Ortega-Salazar, Andres; Chávez-Medina, Jaidy; Cremieux-Grimaldi, Juan C; Correa-Morales, Favián; Hernández-Gaona, Gerson; Méndez-Galván, Jorge F; Beaty, Barry J

2006-05-01

Surveillance for evidence of West Nile virus (WNV) infection in taxonomically diverse vertebrates was conducted in the Yucatan Peninsula of Mexico in 2003 and 2004. Sera from 144 horses on Cozumel Island, Quintana Roo State, 415 vertebrates (257 birds, 52 mammals, and 106 reptiles) belonging to 61 species from the Merida Zoo, Yucatan State, and 7 farmed crocodiles in Ciudad del Carmen, Campeche State were assayed for antibodies to flaviviruses. Ninety (62%) horses on Cozumel Island had epitope-blocking enzyme-linked immunosorbent assay (ELISA) antibodies to flaviviruses, of which 75 (52%) were seropositive for WNV by plaque reduction neutralization test (PRNT). Blocking ELISA antibodies to flaviviruses also were detected in 13 (3%) animals in the Merida Zoo, including 7 birds and 2 mammals (a jaguar and coyote) seropositive for WNV by PRNT. Six (86%) crocodiles in Campeche State had PRNT-confirmed WNV infections. All animals were healthy at the time of serum collections and none had a history of WNV-like illness.

Faith Fictions: "The Word between This World and God"

Science.gov (United States)

Le Tran, Mai-Anh

2009-01-01

The search for religious truth and depth in "fiction" invites a conceptualization of life and fictional narratives as "faith fictions"--narrative accounts of human experiences and the human condition that bridge this world and God. This article juxtaposes "Mother Crocodile", "Hunger", and "Lost in Translation" to highlight the ways in which they,…

Diversity and biogeography of herpetofauna of the Tana river ...

African Journals Online (AJOL)

... visual encounter survey and pitfalls with drift fence methods were used. Additional data derived from the collection of the National Museums of Kenya and the literature were also used. A total of 40 species comprising 16 amphibians (all anurans), and 24 reptiles (14 lizards, 1 crocodile, 8 snakes, 1 tortoise) were recorded.

Clay vein and its implication for uranium exploration activity in the northern part of the Alligator Rivers Uranium Field, northern Australia

International Nuclear Information System (INIS)

Sasao, Eiji

2003-01-01

Clay veins have been found by uranium exploration drilling around the Black Rock uranium prospect in the northern part of the alligator Rivers Uranium Field (ARUF), northern Australia. The mineralogical and chemical features are described to clarify relations with uranium mineralization, because it is not accompanied by uranium mineralization. X-ray diffraction and chemical analysis for major elements indicate that the clay vein consists mainly of chlorite (clinochlore to ferroan clinochlore) and lesser mica clay mineral (t-1M dominant). The clay vein is compared with the clay alteration zone around the uranium deposits in ARUF in terms of mode of occurrence, mineral and chemical compositions. Mineral composition of the clay vein is only in accordance with that of the inner alteration halo of the clay alteration zone. It is, however, different from mineral composition of the outer alteration halo in terms of lack of Fe chlorite in the clay vein. Chemical composition of the clay vein is similar to that of the clay alteration zone, except for lack in the vein of high iron content which is observed in some samples of the alteration zone. As a whole, the feature of the clay vein corresponds to the inner alteration zone around the uranium deposit in ARUF. The mode of occurrence of the clay vein is very different from that of the clay alteration zone. Mode of occurrence, and mineral and chemical compositions of the clay vein resemble a chlorite vein in the Lower to Middle Proterozoic sandstone above the Jabiluka deposit, one of major uranium deposit in the ARUF. Because of the similarity between the clay and the chlorite veins, the clay vein is regarded as marginal facies of an alteration zone. The fluid that formed the clay vein is estimated to have been oxidized, because of the existence of hematite and ubiquitous Mg chlorite. This nature is in accordance with the mineralizing fluid that formed the inner alteration zone in the Nabarlek deposit. In conclusion, the vein

Patterns of distribution and conservation status of freshwater fishes ...

African Journals Online (AJOL)

1995-02-15

Feb 15, 1995 ... Treur River barb Barhus treurensis in the Blyde River; orange-fringed largemouth Chetia brevis in the Komati-. Incomati and Incomati suckermouth ChiJogJanis blfurcus in the Crocodile-Incomati River) (Table I). In addition to the endemic species there are 15 or 16 species like the lungfish. Protopterus ...

Effect of high hydrostatic pressure on the color and texture parameters of refrigerated Caiman (Caiman crocodilus yacare) tail meat.

Science.gov (United States)

Canto, A C V C S; Lima, B R C C; Cruz, A G; Lázaro, C A; Freitas, D G C; Faria, Jose A F; Torrezan, R; Freitas, M Q; Silva, T P J

2012-07-01

The effect of applying high hydrostatic pressure (HHP) on the instrumental parameters of color and texture and sensory characteristics of alligator meat were evaluated. Samples of alligator tail meat were sliced, vacuum-packed, pressurized and distributed into four groups: control, treated with 200 MPa/10 min, 300 MPa/10 min and 400 MPa/10 min, then stored at 4°C±1°C for 45 days. Instrumental color, texture profile and a sensory profiling using quantitative descriptive analysis were carried out on the 1st, 15th, 30th and 45th days of storage. HHP was shown to affect the color and texture of the product, and the sensory descriptors (pmeat, especially low pressures (200 MPa) which can have positive effects on the quality of the product. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of life-history requirements on the distribution of a threatened reptile.

Science.gov (United States)

Thompson, Denise M; Ligon, Day B; Patton, Jason C; Papeş, Monica

2017-04-01

Survival and reproduction are the two primary life-history traits essential for species' persistence; however, the environmental conditions that support each of these traits may not be the same. Despite this, reproductive requirements are seldom considered when estimating species' potential distributions. We sought to examine potentially limiting environmental factors influencing the distribution of an oviparous reptile of conservation concern with respect to the species' survival and reproduction and to assess the implications of the species' predicted climatic constraints on current conservation practices. We used ecological niche modeling to predict the probability of environmental suitability for the alligator snapping turtle (Macrochelys temminckii). We built an annual climate model to examine survival and a nesting climate model to examine reproduction. We combined incubation temperature requirements, products of modeled soil temperature data, and our estimated distributions to determine whether embryonic development constrained the northern distribution of the species. Low annual precipitation constrained the western distribution of alligator snapping turtles, whereas the northern distribution was constrained by thermal requirements during embryonic development. Only a portion of the geographic range predicted to have a high probability of suitability for alligator snapping turtle survival was estimated to be capable of supporting successful embryonic development. Historic occurrence records suggest adult alligator snapping turtles can survive in regions with colder climes than those associated with consistent and successful production of offspring. Estimated egg-incubation requirements indicated that current reintroductions at the northern edge of the species' range are within reproductively viable environmental conditions. Our results highlight the importance of considering survival and reproduction when estimating species' ecological niches, implicating

Clonal integration supports the expansion from terrestrial to aquatic environments of the amphibious stoloniferous herb Alternanthera philoxeroides.

Science.gov (United States)

Wang, N; Yu, F-H; Li, P-X; He, W-M; Liu, J; Yu, G-L; Song, Y-B; Dong, M

2009-05-01

Effects of clonal integration on land plants have been extensively studied, but little is known about the role in amphibious plants that expand from terrestrial to aquatic conditions. We simulated expansion from terrestrial to aquatic habitats in the amphibious stoloniferous alien invasive alligator weed (Alternanthera philoxeroides) by growing basal ramets of clonal fragments in soils connected (allowing integration) or disconnected (preventing integration) to the apical ramets of the same fragments submerged in water to a depth of 0, 5, 10 or 15 cm. Clonal integration significantly increased growth and clonal reproduction of the apical ramets, but decreased both of these characteristics in basal ramets. Consequently, integration did not affect the performance of whole clonal fragments. We propose that alligator weed possesses a double-edged mechanism during population expansion: apical ramets in aquatic habitats can increase growth through connected basal parts in terrestrial habitats; however, once stolon connections with apical ramets are lost by external disturbance, the basal ramets in terrestrial habitats increase stolon and ramet production for rapid spreading. This may contribute greatly to the invasiveness of alligator weed and also make it very adaptable to habitats with heavy disturbance and/or highly heterogeneous resource supply.

Outflow tract septation and the aortic arch system in reptiles: lessons for understanding the mammalian heart.

Science.gov (United States)

Poelmann, Robert E; Gittenberger-de Groot, Adriana C; Biermans, Marcel W M; Dolfing, Anne I; Jagessar, Armand; van Hattum, Sam; Hoogenboom, Amanda; Wisse, Lambertus J; Vicente-Steijn, Rebecca; de Bakker, Merijn A G; Vonk, Freek J; Hirasawa, Tatsuya; Kuratani, Shigeru; Richardson, Michael K

2017-01-01

Cardiac outflow tract patterning and cell contribution are studied using an evo-devo approach to reveal insight into the development of aorto-pulmonary septation. We studied embryonic stages of reptile hearts (lizard, turtle and crocodile) and compared these to avian and mammalian development. Immunohistochemistry allowed us to indicate where the essential cell components in the outflow tract and aortic sac were deployed, more specifically endocardial, neural crest and second heart field cells. The neural crest-derived aorto-pulmonary septum separates the pulmonary trunk from both aortae in reptiles, presenting with a left visceral and a right systemic aorta arising from the unseptated ventricle. Second heart field-derived cells function as flow dividers between both aortae and between the two pulmonary arteries. In birds, the left visceral aorta disappears early in development, while the right systemic aorta persists. This leads to a fusion of the aorto-pulmonary septum and the aortic flow divider (second heart field population) forming an avian aorto-pulmonary septal complex. In mammals, there is also a second heart field-derived aortic flow divider, albeit at a more distal site, while the aorto-pulmonary septum separates the aortic trunk from the pulmonary trunk. As in birds there is fusion with second heart field-derived cells albeit from the pulmonary flow divider as the right 6th pharyngeal arch artery disappears, resulting in a mammalian aorto-pulmonary septal complex. In crocodiles, birds and mammals, the main septal and parietal endocardial cushions receive neural crest cells that are functional in fusion and myocardialization of the outflow tract septum. Longer-lasting septation in crocodiles demonstrates a heterochrony in development. In other reptiles with no indication of incursion of neural crest cells, there is either no myocardialized outflow tract septum (lizard) or it is vestigial (turtle). Crocodiles are unique in bearing a central shunt, the

Total recovery of nitrogen and phosphorus from three wetland plants by fast pyrolysis technology.

Science.gov (United States)

Liu, Wu-Jun; Zeng, Fan-Xin; Jiang, Hong; Yu, Han-Qing

2011-02-01

Fast pyrolysis of three wetland plants (Alligator weed, Oenanthe javanica and Typha angustifolia) in a vertical drop fixed bed reactor was investigated in this study. The experiments were carried out at different pyrolysis temperatures, and the maximum bio-oil yields achieved were 42.3%, 40.2% and 43.6% for Alligator weed, Oenanthe javanica and Typha angustifolia, respectively. The elemental composition of the bio-oil and char were analyzed, and the results show that a low temperature was appropriate for the nitrogen and phosphorus enrichment in char. GC-MS analysis shows that nitrogenous compounds, phenols and oxygenates were the main categories in the bio-oil. A series of leaching tests were carried out to examine the recovery of the nitrogen and phosphorus in the char, and the results indicate that significant fractions of nitrogen and phosphorus could be recovered by leaching process. Copyright © 2010 Elsevier Ltd. All rights reserved.

Southern marl prairies conceptual ecological model

Science.gov (United States)

Davis, S.M.; Loftus, W.F.; Gaiser, E.E.; Huffman, A.E.

2005-01-01

About 190,000 ha of higher-elevation marl prairies flank either side of Shark River Slough in the southern Everglades. Water levels typically drop below the ground surface each year in this landscape. Consequently, peat soil accretion is inhibited, and substrates consist either of calcitic marl produced by algal periphyton mats or exposed limestone bedrock. The southern marl prairies support complex mosaics of wet prairie, sawgrass sawgrass (Cladium jamaicense), tree islands, and tropical hammock communities and a high diversity of plant species. However, relatively short hydroperiods and annual dry downs provide stressful conditions for aquatic fauna, affecting survival in the dry season when surface water is absent. Here, we present a conceptual ecological model developed for this landscape through scientific concensus, use of empirical data, and modeling. The two major societal drivers affecting the southern marl prairies are water management practices and agricultural and urban development. These drivers lead to five groups of ecosystem stressors: loss of spatial extent and connectivity, shortened hydroperiod and increased drought severity, extended hydroperiod and drying pattern reversals, introduction and spread of non-native trees, and introduction and spread of non-native fishes. Major ecological attributes include periphyton mats, plant species diversity and community mosaic, Cape Sable seaside sparrow (Ammodramus maritimus mirabilis), marsh fishes and associated aquatic fauna prey base, American alligator (Alligator mississippiensis), and wading bird early dry season foraging. Water management and development are hypothesized to have a negative effect on the ecological attributes of the southern marl prairies in the following ways. Periphyton mats have decreased in cover in areas where hydroperiod has been significantly reduced and changed in community composition due to inverse responses to increased nutrient availability. Plant species diversity and