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Sample records for cobia rachycentron canadum

  1. Ultrastructure of spermatozoa in cobia, Rachycentron canadum (Linnaeus, 1766).

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    Dhanasekar, Krishnamoorthy; Selvakumar, Narasimman; Munuswamy, Natesan

    2018-02-01

    Ultrastructure and development of spermatozoa in cobia, Rachycentron canadum are described. Sections through the testis show different developmental stages viz, Spermatocytes, spermatids and sperm. Spermatozoa of R. canadum exhibit the configuration of uniflagellated, anacrosomal Type I aquasperm, typical for externally fertilizing fish. Mature spermatozoon is seen with a prominent head and long cylindrical flagellum. Ultrastructure of sperm shows invaginated 'U' shaped nucleus and other organelles. The mitochondrial matrix is electron-dense with irregular arrangement of the cristae. The nucleus reveals a deep invagination (nuclear fossa) in which the centriolar complex is located. The centriolar complex lies inside the nuclear fossa and is composed of a proximal and a distal centriole. The two centrioles are placed perpendicular to each other. The flagellum has a typical eukaryotic organization (microtubule doublets 9 + 2 pattern) and measures around 36.21 ± 0.42 μm in length. This study for the first time provides a comprehensive detail on the ultrastructure and developmental process of sperm in cobia, R. canadum. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. A Case Study on the Mortality of Cobia (Rachycentron canadum) Cultured in Traditional Cages

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    Chu, Kua Beng; Abdulah, Azila; Abdullah, Siti Zahrah; Bakar, Ramley Abu

    2013-01-01

    The mass mortality of cobia (Rachycentron canadum) within 2–3 days was reported by 3 private farms in Bukit Tambun, Pulau Pinang, in February and March 2007. Only cobia with body weights of 3–4 kg were affected. Most diseased cobia swam on the surface and displayed flashing behaviour. All samples were positive for viral nervous necrosis (VNN) with low to medium levels of infection. Infestations by leeches (Zeylanicobdella arugamensis), body monogeneans (Benedenia sp.) and copepods (Caligus sp...

  3. First record of Neobenedenia melleni (Monogenea: Capsalidae) in sea-farmed cobia (Rachycentron canadum) in Brazil.

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    Kerber, Claudia Ehlers; Sanches, Eduardo Gomes; Santiago, Mauricio; Luque, José Luis

    2011-01-01

    Neobenedenia melleni (MacCallum, 1927) (Monogenea) is a widespread pathogen in marine teleost cultures all over the world. The present paper reports this parasite species in farmed cobia (Rachycentron canadum) in Brazil, for the first time. Some comments on preventive actions for avoiding the disease are made.

  4. A Case Study on the Mortality of Cobia (Rachycentron canadum) Cultured in Traditional Cages.

    Science.gov (United States)

    Chu, Kua Beng; Abdulah, Azila; Abdullah, Siti Zahrah; Bakar, Ramley Abu

    2013-12-01

    The mass mortality of cobia (Rachycentron canadum) within 2-3 days was reported by 3 private farms in Bukit Tambun, Pulau Pinang, in February and March 2007. Only cobia with body weights of 3-4 kg were affected. Most diseased cobia swam on the surface and displayed flashing behaviour. All samples were positive for viral nervous necrosis (VNN) with low to medium levels of infection. Infestations by leeches (Zeylanicobdella arugamensis), body monogeneans (Benedenia sp.) and copepods (Caligus sp.) were also found, but no pathogenic bacteria were isolated. All water quality parameters monitored were within optimal ranges for culturing cobia. The main causes of high mortality in cobia remain unclear during the study. However, we believe that the mass mortality of cobia could be probably due to VNN infection and that the rate of mortality will increase further when cobia are subjected to aquaculture-related stresses (e.g., limited space). Traditional cages with a size of 2 (length) × 2 (width) × 1 m (depth) should only be used for rearing cobia below 1 kg in weight given the species' natural behaviours. In addition, cobia fingerlings should be screened for VNN prior to stocking them in cages.

  5. Probiotic effects on cobia Rachycentron canadum larvae reared in a recirculating aquaculture system

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    M. Angélica Garrido-Pereira

    2014-11-01

    Full Text Available Cobia (Rachycentron canadum is a marine finfish with good potential for mariculture. This study analyzes the effects of probiotic Bacillus spp. on the performance of cobia larvae reared in a recirculating aquaculture system (RAS. Larvae were stocked into two independent RAS for 26 days after hatching. One of the systems (Probiotic treatment received the addition of a commercial probiotic consisting of B. subtilis, B. licheniformis and B. pumilus directly into the water and by live feed. Survival, final weight and water quality were not affected by probiotics. Results showed larvae of the probiotic treatment demonstrated a greater resistance to salinity stress. Immunohistochemical analysis showed a higher expression of CD4 in probiotic treatment. These results suggest that Bacillus spp. probiotics used in RAS have a potential stimulating impact on immune system differentiation and increases salinity stress resistance of cobia larvae.

  6. Stocking density effects on production characteristics and body composition of market size cobia, Rachycentron canadum, reared in recirculating aquaculture systems

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    Production density in excess of a critical threshold can result in a negative relationship between stocking density and fish production. This study was conducted to evaluate production characteristics of juvenile cobia Rachycentron canadum, reared to market size in production-scale recirculating aq...

  7. Virulence of Photobacterium damselae subsp. piscicida in cultured cobia Rachycentron canadum.

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    Liu, Ping-Chung; Lin, Ji-Yang; Lee, Kuo-Kau

    2003-01-01

    An outbreak of serious mortality among the cultured cobia Rachycentron canadum (weighing 3 kg) characterized by the presence of whitish granulomatous deposits on the kidney, liver and spleen occurred in July of 2000 in Taiwan. A non-motile strain CP1 was isolated from kidney and/or liver on tryptic soy agar and/or brain heart infusion agar plates (both supplemented with 1% NaCl, w/v). This strain was characterized and identified as Photobacterium damselae subsp. piscicida using biochemical characteristics and Bionor mono-Pp tests. The bacterium and its extracellular products (ECP) were lethal to the cobia (weighing 10 g) with LD50 values of 1.03 x 10(4) colony forming units and 1.26 microg protein/g fish body weight, respectively. All the moribund/dead fish exhibited darkness in color with no gross or internal leasions. However, the bacteria could be reisolated from kidney and liver after bacterial challenge. The present results reveal that Ph. damselae subsp. piscicida is the causative agent of fish photobacteriosis in the cobia and the bacterium isolated from sub-adult cobia (chronic form) is virulent to young cobia causing acute form of the disease.

  8. Genetic characteristics of Streptococcus dysgalactiae isolated from cage cultured cobia, Rachycentron canadum (L.).

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    Tsai, M-A; Wang, P-C; Yoshida, T; Chen, S-C

    2015-12-01

    Disease outbreaks occurred during 2007-2013 in Taiwan with 2.5-10% mortality among the cage cultured cobia, Rachycentron canadum (L.), characterized by the presence of polyserositis, pericarditis and peritonitis. The micro-organisms isolated from internal organs were Gram-positive cocci. The isolates were confirmed as Streptococcus dysgalactiae by a polymerase chain reaction assay that yielded the expected specific 259 bp amplicon. Additionally, partial sequence of the 16S-23S rDNA intergenic spacer region of the GCS strain isolates from fish was also compared and produced 100% sequence identity with S. dysgalactiae (GenBank accession number AB252398). The genetic characterization was then determined by pulsed-field gel electrophoresis (PFGE) analysis. Based on PFGE, the Apa I or Sma I digestion patterns of chromosomal DNA of these isolates were grouped into three main clusters. Taiwanese strains were divided into two clusters, and the tet(M) gene was detected in cluster 1 (pulsotypes: A1-A2 and S1-S3), but not in cluster 2 strains (pulsotypes: A3-A4 and S4-S5). Three Japanese strains from amberjack, Seriola dumerili (Risso), were grouped into cluster 3 (pulsotypes: A5-A7 and S6-S8) and displayed no mortality to cobia in the challenge experiment. Conversely, Taiwanese strains from cobia and snubnose pompano, Trachinotus blochii (L.), displayed a mortality rate of 50-87.5% in cobia. © 2014 John Wiley & Sons Ltd.

  9. Ocular localization of mycobacterial lesions in tank-reared juvenile cobia, Rachycentron canadum.

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    Phillips, A C N; Suepaul, R; Soto, E

    2017-12-01

    Severe clinical mycobacteriosis with consistent ocular lesion localization was diagnosed in a population of 800 juvenile tank-reared Cobia (Rachycentron canadum) which experienced a sudden increase in mortality approximately 5 months after arriving into Trinidad and Tobago from Florida, USA. Moderate daily mortality (15-20 animals per day) persisted for just over 1 month. Moribund fish displayed circling behaviour and had an open-mouth gape upon death. Fish consistently presented with bilateral exophthalmia, corneal cloudiness and hyphema. Non-branching acid-fast rods were detected in aqueous humour touch preparations. Histological analysis revealed severe bilateral intra-ocular granulomatous responses in all specimens. Mycobacterium sp. was identified using a real-time PCR assay detecting the RNA polymerase β-subunit (rpoB) gene in different tissue samples. Specimens did not present with characteristic granulomatous responses usually seen in viscera. To the best of our knowledge, this represents only the third documentation of piscine mycobacterial infection presenting with only localized ocular lesions, and the second documented case of mycobacteriosis in cobia. It is, however, the first documentation of an ocular presentation of mycobacteriosis in a marine species and is the first documentation of such a presentation in cobia. © 2017 John Wiley & Sons Ltd.

  10. Isolation and characterization of pathogenic Vibrio alginolyticus from diseased cobia Rachycentron canadum.

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    Liu, Ping-Chung; Lin, Ji-Yang; Hsiao, Pei-Tze; Lee, Kuo-Kau

    2004-01-01

    Outbreaks of serious mortality among cultured juvenile cobia Rachycentron canadum L. (weighing 8-10 g) characterized by lethargy, dark skin and ascites in the peritoneal cavity while some fish possessing damaged eyes occurred in July and August of 2001 in Taiwan. Fifteen motile bacterial strains were isolated from head kidney and/or the ascites on tryptic soy agar supplemented with 1% NaCl (TSA1) and/or thiosulphate citrate bile salt (TCBS) sucrose agar plates during the two outbreaks. All the isolates were characterized and identified as Vibrio alginolyticus on the basis of biochemical characteristics, and comparisons with those of the reference strain V. alginolyticus ATCC 17749. The strain C3c01 (a representative of the 15 similar field isolates), was virulent to the cobia with an LD50 value of 3.28 x 10(4) colony forming units/g fish body weight. All the moribund/dead fish exhibited lethargy, dark skin and ascites in the peritoneal cavity as that observed in natural outbreaks. The same bacteria could be reisolated from kidney and the ascites of fish after bacterial challenge using TSA1 and TCBS plates. The results reveal that V. alginolyticus is an infectious agent of vibriosis in the cobia.

  11. STUDY OF VERTEBRAL MORPHOGENESIS OF COBIA LARVAE, (Rachycentron canadum BY DOUBLE STAINING METHODS

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    Afifah Nasukha

    2012-12-01

    Full Text Available Vertebral development is one of the main indicators of organism growth. The aim of this study was to know the vertebral development of cobia Rachycentron canadum in larval stage (20 day post hatch. Vertebral assay was done with double staining methods. The result showed that cobia larvae from 0 dph up to 5 dph did not have cartilage. On 5 dph up to 10 dph had pre cartilage phase composed by calcium and on 10 dph up to 18 dph were cartilage phase and marked with blue color by alcian blue. Vertebral was formed perfectly as bones on 18 dph marked with red color by alizarin red. On 20 dph, cartilage had been fully transformed to bones, and the segment of vertebral was clearly formed. Measurement showed that length of cobia vertebrae was 20.20±3.90 mm, vertebrae segment was 0.91±0.11 mm and number of vertebral segments were between 25-26 segments.

  12. New records of parasites for culture Cobia, Rachycentron canadum (Perciformes: Rachycentridae in Puerto Rico

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    Lucy Bunkley-Williams

    2006-12-01

    Full Text Available Intensive aquaculture sometimes provides conditions favorable for parasites that are not ordinarily found on culture fishes in the wild, and the use of introduced stocks sometimes introduces non-indigenous species to the habitat. When officially asked about the culture of Cobia Rachycentron canadum (Linnaeus in Puerto Rico, the authors responded that it was unlikely to cause harm. It was assumed that a well-known culture facility in Florida would assure parasite-free stocks. Subsequent examinations of stocked juveniles surprisingly found parasites new to this fish. An outbreak of Slime-blotch disease, Brooklynella hostilis Lom & Nigrilli, 1970 (Dysteriida: Hartmannulidae occurred in juvenile Cobia after they were shipped from Florida and stocked. This apparently represents a local parasite that took advantage of the weakened and/or crowded fish. The universal aquarium and culture superparasite, Marine Ich, Cryptocaryon irritans Brown, 1951 (Colpodia: Ichthyophthiriidae was introduced with a shipment of juvenile Cobia from Florida. This may not be serious, since the parasite occurs worldwide, unless it represents a new strain to Puerto Rico. Marine Costia, Ichthyobodo sp. (Kinetoplastida: Bodonidae was introduced into Puerto Rico with juvenile Cobia shipped from Florida. This parasite has caused some severe problems in aquaculture hatcheries in Hawaii and Texas after it was introduced with cultured organisms. Thus far, it has not caused any problems locally, but Puerto Rico lacks the marine hatchery facilities where such outbreaks would occur. The question of whether it is established locally will have to wait the development of similar facilities in Puerto Rico. These three species of parasites represent new host records for Cobia. The non-indigenous Ichthyobodo sp. represents new locality records for the tropical Atlantic, Caribbean, and Florida and Puerto Rico. Cobia mature more quickly in culture than in the wild and thus female Cobia

  13. Purification and characterization of a phospholipase by Photobacterium damselae subsp. piscicida from cobia Rachycentron canadum.

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    Hsu, Po-Yuan; Lee, Kuo-Kau; Hu, Chih-Chuang; Liu, Ping-Chung

    2014-09-01

    Toxicity of the extracellular products (ECPs) and the lethal attributes of phospholipase secreted by pathogenic Photobacterium damselae subsp. piscicida from cobia Rachycentron canadum was studied. An extracellular lethal toxin in the ECPs was partially purified by using Fast Protein Liquid Chromatography system. A protein band (27 kDa) exhibited phospholipase activity on Native-PAGE (by 0.3% egg yolk agar-overlay), was excised and eluted. The pI value of the purified phospholipase was determined as 3.65 and was determined as a phospholipase C by using the Amplex™ Red phosphatidylcholine -Specific phospholipase C Assay kit. The phospholipase showed maximum activity at temperature around 4-40 °C and maximal activity at pH between 8 and 9. The enzyme was inhibited by ethylenediamine-tetraacetic acid (EDTA) and sodium dodecyl sulfate (SDS); but was activated by Ca(2+) and Mg(2+) and inactivated by Zn(2+) and Cu(2+) . Both the ECPs and phospholipase were hemolytic against erythrocytes of cobia and lethal to the fish with LD50 values of 3.25 and 0.91 µg protein g(-1) fish, respectively. In toxicity neutralization test, the rabbit antisera against the phospholipase could neutralize the toxicity of ECPs, indicating that the phospholipase is a major extracellular toxin produced by the bacterium. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Physical properties of cobia (Rachycentron canadum) surimi: effect of washing cycle at different salt concentrations.

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    Hamzah, N; Sarbon, N M; Amin, A M

    2015-08-01

    This study aimed to determine the effects of 2-5 wash cycles and the addition of tetrasodium pyrophosphate (TSPP) (0 %, 0.05 Surimi% and 0.1 % w/w)-with or without the addition of 0.4 % calcium chloride (CaCl2)-on the physical properties such as texture, colour, expressible moisture and microstructure of Cobia (Rachycentron canadum) surimi gel. The highest breaking force (484.85 g) was obtained with the addition 0.1 % TSPP alone on the fifth wash. However, a combination of 0.1 and 0.4 % CaCl2 in surimi gels at wash cycle 5 resulted in the highest degree of whiteness (86.8 %), as well as total expressible moisture (2.785 %) and deformation (17.11 mm). The highest surimi gel strength (6,923 g.mm) was obtained after three wash cycles with the addition of 0.1 % TSPP +0.4 % CaCl2. The physical properties of Cobia fish surimi gels were affected by the number of wash cycles and treatments with TSPP and CaCl2.

  15. Purification, characterization and molecular cloning of alpha-2-macroglobulin in cobia, Rachycentron canadum.

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    Chuang, Wen-Hsiao; Liu, Ping-Chung; Hung, Chia-Yu; Lee, Kuo-Kau

    2014-12-01

    Alpha-2-macroglobulin (α-2-M) is a broad spectrum protease inhibitor which is abundant in the plasma of vertebrates and several invertebrates. The α-2-M was purified from cobia (Rachycentron canadum) plasma by a four-step procedure: poly ethylene glycol fractionation, affinity chromatography, hydrophobic interaction chromatography and ion exchange chromatography on Fast Protein liquid chromatography system in the present study. It migrated as one protein band with a molecular mass of about 360 kDa in the native state, whereas in SDS-PAGE it was about 180 kDa under non-reducing condition. This result revealed that the native protein was a dimer. In addition, it was cleaved into two different fragments of molecular mass about 93 and 87 kDa when reduced by dithiothreitol (DTT). The anti-protease activity of the purified α-2-M was apparently decreased as temperature elevated above 50 °C. The α-2-M exhibited highest protease inhibitory activity at pH 9. The results indicate that the α-2-M is a heat-labile and alkaline protease inhibitor. The purified α-2-M exhibited more than 50% protease inhibitory activity against extracellular products (ECP) of Vibrio alginolytius isolated from diseased cobia. It seems that the protease activities in ECP may be affected by the plasma α-2-M. The protease inhibitory activities of cobia plasma or purified α-2-M were decreased when incubated with 10 mM methylamine for 30 min. The α-2-M cDNA consisted of 4611 bp with an open reading frame of 4374 bp had been cloned from cobia liver. This sequence contained thioester domain (GCGEQ) and thirteen predicted N-linked glycosylation sites. In addition, the amino acid sequence of thioester domain and genes of adjacent regions of cobia α-2-M were further compared with sequences of known fish species in GenBank. The unweighted pair group method using arithmetic average (UPGMA) was employed to construct the phylogenetic trees of α-2-M among different fish species (freshwater fish, sea

  16. PENUNDAAN PEMBERIAN PAKAN ARTEMIATERHADAP PERFORMANSI BENIH IKAN COBIA (Rachycentron canadum YANG DIPELIHARA SECARA TERKONTROL

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    Titiek Aslianti

    2016-11-01

    Full Text Available Upaya kontinuitas produksi benih ikan cobia, Rachycentron canadum telah dilakukan namun besarnya biaya operasional dalam penggunaan artemia sebagai pakan masih menjadi faktor pembatas. Oleh karena itu, perlu dilakukan penelitian penundaan pemberian artemia dengan tujuan untuk mengetahui waktu yang tepat saat awal diberikan artemia sehingga penggunaannya efektif dan efisien. Penelitian dilakukan dengan menggunakan wadah berupa bak fiber (1 m3 berjumlah 9 unit yang diisi telur cobia sebanyak 3.000 butir/bak dan larva dipelihara hingga mencapai ukuran benih (± 3 cm/umur 20 hari. Rancangan penelitian adalah acak lengkap yang terdiri atas 3 perlakuan yaitu perbedaan waktu awal pemberian artemia yakni pada larva (A umur 5 hari; (B umur 10 hari; dan (C umur 15 hari. Masing-masing perlakuan diulang 3 kali. Data pertumbuhan dan sintasan dianalisis menggunakan sidik ragam. Performansi fisik dan perkembangan tulang belakang diamati sebagai data pendukung. Hasil penelitian menunjukkan bahwa pertumbuhan panjang, bobot, ataupun sintasan di antara perlakuan secara statistik tidak menunjukkan perbedaan yang nyata (P>0,05. Namun pemberian artemia pada larva umur 5 hari (perlakuan A menghasilkan pertumbuhan panjang (28 mm dan bobot badan (74,067 mg serta sintasan (12,07% relatif lebih tinggi daripada perlakuan B ataupun C. Penundaan pemberian artemia lebih dari 5 hari justru menghasilkan benih yang bertumbuh lebih lambat dan banyak mengalami kematian. Hasil pengamatan terhadap perkembangan tulang belakang pada semua perlakuan tidak menunjukkan performansi tulang belakang yang abnormal.  The effort to guarantee a sustainable seed production of cobia, Rachycentron canadum have been carried out but the weight of operational cost in the use of artemia as food has been a problem. The aim of the experiment was to describe the exact and effective time for the initial feeding of seed of cobia using Artemia nauplii. Nine concrete tanks with 1 m3 capacity were stocked

  17. Outbreak of mortality among cage-reared cobia (Rachycentron canadum associated with parasitism

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    Cauê Bonucci Moreira

    Full Text Available This study reports a disease outbreak among juvenile cobia (Rachycentron canadum farmed in cages in the state of Rio de Janeiro, Brazil, caused by the dinoflagellate Amyloodinium ocellatum and the monogenean Neobenedenia melleni. Two thousand five hundred fish were stocked at 0.4 kg/m3 in a set of 12 m3 tanks, in autumn (mean weight 15.0 ± 7.3 g and in winter (mean weight 43.0 ± 5.6 g. Freshwater baths were administered as a routine treatment, as the symptoms were detected followed by two collection samples. Firstly in May 2011 (n = 5 and secondly in September 2011 (n = 10. In the first sample, the prevalence of N. mellenion the body surface was 100% and the mean intensity was 42.0 ± 1.7, while in the second sample the prevalence was 60% with a mean intensity 3.0 ± 0.2 and mean abundance 1.8 ± 0.4. Amyloodinium ocellatum was only found in the second sample, at a prevalence 100% and mean intensity 46.8 ± 3.4. The cause of fish mortality was possibly associated with a decrease in fish resistance after the first contact with monogenean parasites, allied with respiratory difficulty caused by the presence of A. ocellatum in the gills.

  18. Rachycentron canadum (cobia) lectin promoted mitogenic response in mice BALB/c splenocytes.

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    Coriolano, M C; de Melo, C M L; Santos, A J G; Pereira, V R A; Coelho, L C B B

    2012-12-01

    The mitogenic lectins are invaluable tools to study the biochemical changes associated with lymphocyte activation and proliferation of various immune cells. Rachycentron canadum lectin (RcaL) was detected and purified from serum of cobia fish. The aim of this study was to evaluate the proliferative response and cytokine production in splenocytes of mice in vitro stimulated with RcaL lectin; Canavalia ensiformis lectin (Con A) was used as positive control. A high proliferation index was induced by RcaL in relation to control cells. Furthermore, RcaL induced higher IL-2 and IL-6 production in relation to control. The cell viability was 90% in splenocytes treated with RcaL lectin, but RcaL promoted significant late apoptosis after 24 and 48 h in relation to control. RcaL induced proliferative responses suggesting that this lectin can be used as a mitogenic agent in immunostimulatory assays. © 2012 The Authors. Scandinavian Journal of Immunology © 2012 Blackwell Publishing Ltd.

  19. Outbreak of mortality among cage-reared cobia (Rachycentron canadum) associated with parasitism.

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    Moreira, Cauê Bonucci; Hashimoto, Gabriela Sayuri de Oliveira; Rombenso, Artur Nishioka; Candiotto, Fernanda Braz; Martins, Maurício Laterça; Tsuzuki, Mônica Yumi

    2013-01-01

    This study reports a disease outbreak among juvenile cobia (Rachycentron canadum) farmed in cages in the state of Rio de Janeiro, Brazil, caused by the dinoflagellate Amyloodinium ocellatum and the monogenean Neobenedenia melleni. Two thousand five hundred fish were stocked at 0.4 kg/m3 in a set of 12 m3 tanks, in autumn (mean weight 15.0 ± 7.3 g) and in winter (mean weight 43.0 ± 5.6 g). Freshwater baths were administered as a routine treatment, as the symptoms were detected followed by two collection samples. Firstly in May 2011 (n = 5) and secondly in September 2011 (n = 10). In the first sample, the prevalence of N. melleni on the body surface was 100% and the mean intensity was 42.0 ± 1.7, while in the second sample the prevalence was 60% with a mean intensity 3.0 ± 0.2 and mean abundance 1.8 ± 0.4. Amyloodinium ocellatum was only found in the second sample, at a prevalence 100% and mean intensity 46.8 ± 3.4. The cause of fish mortality was possibly associated with a decrease in fish resistance after the first contact with monogenean parasites, allied with respiratory difficulty caused by the presence of A. ocellatum in the gills.

  20. Identification of a cobia (Rachycentron canadum) CC chemokine gene and its involvement in the inflammatory response.

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    Su, Youlu; Guo, Zhixun; Xu, Liwen; Jiang, Jingzhe; Wang, Jiangyong; Feng, Juan

    2012-01-01

    The chemokines regulate immune cell migration under inflammatory and physiological conditions. We investigated a CC chemokine gene (RcCC1) from cobia (Rachycentron canadum). The full-length RcCC1 cDNA is comprised 673 nucleotides and encodes a four-cysteine arrangement 99-amino-acid protein typical of known CC chemokines. The genomic DNA of RcCC1 consists of three exons and two introns. Phylogenetic analysis showed that RcCC1 was closest to the MIP group of CC chemokines. Quantitative real-time RT-PCR (qRT-PCR) analysis revealed RcCC1 was constitutively expressed in all tissues examined, with relative strong expression in gill, blood, kidney, spleen, and head kidney. The RcCC1 transcripts in the head kidney, spleen, and liver were quickly up-regulated after stimulation with formalin-inactivated Vibrio carchariae (bacterial vaccine) or polyriboinosinic polyribocytidylic acid (poly I:C). These results indicate RcCC1 not only plays a role in homeostasis, but also may be involved in inflammatory responses to bacterial and viral infection. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Identification and expression analysis of a CC chemokine from cobia (Rachycentron canadum).

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    Feng, Juan; Su, Youlu; Guo, Zhixun; Xu, Liwen; Sun, Xiuxiu; Wang, Yunxin

    2013-06-01

    Chemokines are small, secreted cytokine peptides known principally for their ability to induce migration and activation of leukocyte populations and regulate the immune response mechanisms. The cobia (Rachycentron canadum), a marine finfish species, has a great potential for net cage aquaculture in the South China Sea. We isolated and characterized a CC chemokine cDNA from cobia-designated RcCC2. Its cDNA is 783 bp in length and encodes a putative protein of 110 amino acids. Homology and phylogenetic analysis revealed that the RcCC2 gene, which contains four conserved cysteine residues, shares a high degree of similarity with other known CC chemokine sequences and is closest to the CCL19/21 clade. The mRNA of RcCC2 is expressed constitutively in all tested tissues, including gill, liver, muscle, spleen, kidney, head kidney, skin, brain, stomach, intestine and heart, but not blood, with the highest level of expression in gill and liver. The reverse transcription quantitative polymerase chain reaction was used to examine the expression of the RcCC2 gene in immune-related tissues, including head kidney, spleen and liver, following intraperitoneal injection of the viral mimic polyriboinosinic polyribocytidylic acid, formalin-killed Vibrio carchariae (bacterial vaccine) and phosphate-buffered saline as a control. RcCC2 gene expression was up-regulated differentially in head kidney, spleen and liver during 12 h after challenge. These results indicate that the RcCC2 gene is inducible and is involved in immune responses, suggesting RcCC2 has an important role in the early stage of viral and bacterial infections.

  2. Characteristic and antioxidant activity of retorted gelatin hydrolysates from cobia (Rachycentron canadum) skin.

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    Yang, Jing-Iong; Ho, Hsin-Yi; Chu, Yuh-Jwo; Chow, Chau-Jen

    2008-09-01

    Alkali-pretreated cobia (Rachycentron canadum) skin was extracted in a retort (121°C) for 30min to obtain a retorted skin gelatin hydrolysate (RSGH). The molecular mass distributions and antioxidant activities of cobia RSGH and enzyme-treated RSGHs (ET-RSGHs) derived from bromelain, papain, pancreatin, and trypsin digestion were then characterized. The molecular mass distribution of the RSGH ranged mainly between 20,000 and 700Da and those of ET-RSGHs ranged between 6500 and 700Da. The DPPH (α,α-diphenyl-β-picrylhydrazyl) radical scavenging effects (%) of 10mg/ml of RSGH and 10mg/ml of the four ET-RSGHs were 55% and 51-61%, respectively. The lipid peroxidation inhibition (%) of RSGH and ET-RSGHs (10mg/ml) were 58% and 60-71% on the fifth day in a linoleic acid model system, respectively. The 3Kd-ET-RSGHs, obtained by using a series of centrifugal ultrafiltration filters (molecular weight cut-offs of 10, 5, and 3kDa done sequentially with decreasing pore size), exhibited dramatically improved antioxidant activity, with most of the molecular mass ranging below 700Da. Compared to 10mg/ml of the RSGH, 10mg/ml of 3Kd-ET-RSGHs exhibited 45-65% more scavenging of DPPH radical and 24-38% more inhibition of lipid peroxidation. The peptides with molecular masses below 700Da in the ET-RSGHs or 3Kd-ET-RSGHs significantly affect the antioxidant properties. These peptides are composed of a small number of amino acids or free amino acids and have the potential to be added as antioxidants in foods. Copyright © 2008 Elsevier Ltd. All rights reserved.

  3. Taurine supplementation of plant derived protein 1 and n-3 fatty acids are critical for optimal growth and development of cobia, rachycentron canadum

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    We examined growth performance and lipid content in juvenile cobia, Rachycentron canadum, fed a taurine supplemented (1.5%), plant protein based diet with two fish oil replacements. The first fish oil replacement was a thraustochytrid meal (TM+SOY) plus soybean oil (~9% CL) and the second was a cano...

  4. First record of Neobenedenia melleni (Monogenea: Capsalidae in sea-farmed cobia (Rachycentron canadum in Brazil Primeiro registro de Neobenedenia melleni (Monogenea: Capsalidae em cultivo de bijupirás (Rachycentron canadum no Brasil

    Directory of Open Access Journals (Sweden)

    Claudia Ehlers Kerber

    2011-12-01

    Full Text Available Neobenedenia melleni (MacCallum, 1927 (Monogenea is a widespread pathogen in marine teleost cultures all over the world. The present paper reports this parasite species in farmed cobia (Rachycentron canadum in Brazil, for the first time. Some comments on preventive actions for avoiding the disease are made.Neobenedenia melleni (MacCallum, 1927 (Monogenea é um patógeno amplamente distribuído em cultivo de teleósteos marinhos no mundo. Este estudo relata pela primeira vez essa espécie de parasito em cultivo de cobia, Rachycentron canadum, no Brasil. Comentários sobre prevenção para evitar a doença são discutidos.

  5. Anisakis simplex (Nematoda: Anisakidae) third-stage larval infections of marine cage cultured cobia, Rachycentron canadum L., in Taiwan.

    Science.gov (United States)

    Shih, Hsiu-Hui; Ku, Chen-Chun; Wang, Chun-Shun

    2010-08-04

    The first confirmed case of Anisakis simplex infection of the marine cage cobia, Rachycentron canadum (L.), was recorded in Taiwan. The case investigation revealed the presence of third-stage larvae (L3) in either the stomach lumen or abdominal cavity of the cobia but never within the musculatures. Larvae were mainly encapsulated in the peritoneal mesentery on the outer surface of the stomach wall and occasionally on the liver surface. Part of the diet fed to the cobia includes chopped raw fish, and of these, seven species were found to harbor these larvae (as paratenic hosts), indicating that these particular fish might be the larval sources for this infection. To illustrate the course of infection and distribution of this parasite inside cobia, both juvenile and adult cobia were experimentally infected with live L3 by oral transmission. The prevalence of infection reached 100% at the end of all trials. The course of the infection was assessed after necropsy by histological and ultrastructural observations. A. simplex L3 recovered from various locations within juvenile cobia at different post-infection (p.i.) times were at the L3 stage and did not grow significantly. The L3 either adhered to or penetrated into the gastric mucosa of cobia by 2 h p.i. By 25 d p.i., many were trapped within the submucosa and encapsulated by fibroconnective tissue. This phenomenon was more apparent in adult cobia, such that 37.5-86.0% of the injected L3 were primarily found encapsulated within the gastric submucosa. Based upon a PCR-RFLP assay, the larvae encountered in this study were identified as having a recombinant genotype of A. simplex sensu stricto and A. pegreffii. Based upon the results of this study, strategies to ensure the safety of seafood manufactured from cobia and to prevent the potential risks of anisakiasis or allergies risk to consumers were suggested. Copyright 2010 Elsevier B.V. All rights reserved.

  6. Morphological development of larval cobia Rachycentron canadum and the influence of dietary taurine supplementation.

    Science.gov (United States)

    Salze, G; Craig, S R; Smith, B H; Smith, E P; McLean, E

    2011-05-01

    The morphological development of larval cobia Rachycentron canadum from 3 days post hatch (dph) until weaning (27 dph) was examined using S.E.M. Two groups of fish were studied: a control group (CF), reared under standard feeding protocol, and a group in which prey items were enriched with supplemental taurine (4 g l(-1) day(-1) ; TF). TF fish grew faster (P < 0·001), attained greater size (mean ±s.e. 55·1 ± 1·5 v. 33·9 ± 1·0 mm total length) and had better survival (mean ±s.e. 29·3 ± 0·4 v. 7·1 ± 1·2 %) than CF fish. Canonical variance analysis confirmed findings with respect to differences in growth between the treatment groups with separation being explained by two cranial measurements. S.E.M. revealed that 3 dph larvae of R. canadum (in both groups) possess preopercular spines, superficial neuromasts on the head and body, taste buds in the mouth, an olfactory epithelium which takes the form of simple concave depressions, and primordial gill arches. Gill filaments start to form as early as 6 dph and lamellae buds are visible at 8 dph in both groups. In CF fish, the cephalic lateral line system continues its development at 12-14 dph with invagination of both supra- and infraorbital canals. At the same time, a thorn-like or acanthoid crest forms above the eye. At 14 dph, invaginations of the mandibular and preopercular canals are visible and around 22 dph enclosure of all cranial canals nears completion. In CF larvae, however, completely enclosed cranial canals were not observed within the course of the trial, i.e. 27 dph. In TF larvae, grooves of the cephalic lateral line system form 4 days earlier than observed in CF larvae of R. canadum (i.e. at 8 dph), with enclosure commencing at 16 dph, and completed by 27 dph. Along the flanks of 6 dph larvae of either treatment, four to five equally spaced neuromasts delineate the future position of the trunk lateral line. As myomeres are added to the growing larvae, new neuromasts appear such that at 16 dph

  7. Establishment, characterization, virus susceptibility and transfection of cell lines from cobia, Rachycentron canadum (L.), brain and fin.

    Science.gov (United States)

    Cheng, T-C; Lai, Y-S; Lin, I-Y; Wu, C-P; Chang, S-L; Chen, T-I; Su, M-S

    2010-02-01

    Establishment and characterization of two cobia, Rachycentron canadum, cell lines derived from cobia brain (CB) and cobia fin (CF) are described. Caudal fin and brain from juvenile cobia were dissociated for 30 and 10 min, respectively, in phosphate-buffered saline containing 0.25% trypsin at 25 degrees C. The optimal culture condition for both dissociated cells (primary cell culture) was at 28 degrees C in Leibovitz-15 medium containing 10% foetal bovine serum. The cells have been sub-cultured at a ratio of 1:2 for more than 160 passages over a period of 3 years. Origin of the cultured cells was verified by comparison of their sequences of mitochondrial cytochrome oxidase subunit I genes (cox I) with the cox 1 sequence from cobia muscle tissue. The cell lines showed polyploidy. No mycoplasma contamination was detected. Susceptibility to grouper iridovirus was observed for the CB cell line but not the CF cell line. Both cell lines expressed green fluorescent protein after being transfected with green fluorescent reporter gene driven by the cytomegalovirus promoter.

  8. Diet supplementation of Pediococcus pentosaceus in cobia (Rachycentron canadum) enhances growth rate, respiratory burst and resistance against photobacteriosis.

    Science.gov (United States)

    Xing, Chen-Fu; Hu, Hung-Hsi; Huang, Jian-Bin; Fang, Han-Chun; Kai, Yu-Hsuan; Wu, Yu-Chi; Chi, Shau-Chi

    2013-10-01

    Cobia (Rachycentron canadum) is an economically important fish species for aquaculture in tropical and sub-tropical areas. Cobia aquaculture industry has severely damaged due to photobacteriosis caused by Photobacterium damselae subsp. piscicida (Pdp), especially in Taiwan. Antibiotics and vaccines have been applied to control Pdp infection, but the efficacy has been inconsistent. One species of lactic acid bacteria, Pediococcus pentosaceus strain 4012 (LAB 4012), was isolated from the intestine of adult cobia, and its culture supernatant can effectively inhibit Pdp growth in vitro. The acidic pH derived from metabolic acids in LAB culture supernatant was demonstrated to be an important factor for the suppression. After a 2-week feeding of LAB 4012, the growth rate of the fed cobia was 12% higher than that of the non-fed group, and the relative percentage of survival (RPS) of the fed cobia was found to be 74.4 in Pdp immersion challenge. In addition, the respiratory burst (RB) of peripheral blood leukocytes (PBL) in the LAB 4012-fed group was significantly higher than that of the non-fed group. Although feeding LAB 4012 did not improve specific antibody response in cobia after immunization with Pdp vaccine, it still significantly raised the survival rate by 22% over that of the non-fed group after Pdp immersion challenge. Judging by the quick induction of high protection against Pdp infection and promotion of growth in larvae, LAB 4012 was considered to be a viable probiotic for cobia aquaculture. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Weak genetic differentiation in cobia, Rachycentron canadum from Indian waters as inferred from mitochondrial DNA ATPase 6 and 8 genes.

    Science.gov (United States)

    Joy, Linu; Mohitha, C; Divya, P R; Gopalakrishnan, A; Basheer, V S; Jena, J K

    2016-07-01

    Cobia, Rachycentron canadum, is an economically important migratory fish distributed in tropical waters worldwide and is a candidate fish species for aquaculture practices. The genetic stock structure of R. canadum distributed along the Indian waters was identified using mitochondrial ATPase 6 and 8 genes. A total of 842 bp sequence of ATPase 6/8 genes obtained in this study revealed 15 haplotypes with mean low nucleotide diversity (π = 0.001) and high haplotype diversity (h = 0.785). AMOVA indicated the genetic differentiation of 90.47% for individuals within the population. This is well supported by co-efficient of genetic differentiation (FST) values obtained for pairwise populations that were low and non-significant with an overall value of 0.002. The parsimony network tree revealed star-like phylogeny and all the haplotypes were connected with each other by single mutational event. The findings of the present study indicated the panmixia nature of the species which can be managed as a unit stock in Indian waters.

  10. Purification of a toxic metalloprotease produced by the pathogenic Photobacterium damselae subsp. piscicida isolated from cobia (Rachycentron canadum).

    Science.gov (United States)

    Liu, Ping-Chung; Chuang, Wen-Hsiao; Lee, Kuo-Kau

    2011-01-01

    The aim of the present study was to purify and characterize a toxic protease secreted by the pathogenic Photobacterium damselae subsp. piscicida strain CP1 originally isolated from diseased cobia (Rachycentron canadum). The toxin isolated by anion exchange chromatography, was a metalloprotease, inhibited by L-cysteine, ethylenediaminetetraacetic acid (EDTA), ethylene glycol-bis(beta-aminoethyl ether)N,N,N',N'-tetraacetic acid (EGTA), 1,10-phenanthroline, N-tosyl-L-phenylalanine-chloromethyl ketone (TPCK), and N-alpha-p-tosyl-L-lysine-chloromethyl ketone (TLCK), and showed maximal activity at pH 6.0-8.0 and an apparent molecular mass of about 34.3 kDa. The toxin was also completely inhibited by HgCl2, and partially by sodium dodecyl sulfate (SDS) and CuCl2. The extracellular products and the partially purified protease were lethal to cobia with LD50 values of 1.26 and 6.8 microg protein/g body weight, respectively. The addition of EDTA completely inhibited the lethal toxicity of the purified protease, indicating that this metalloprotease was a lethal toxin produced by the bacterium.

  11. Cardio-respiratory function during exercise in the cobia, Rachycentron canadum: The impact of crude oil exposure.

    Science.gov (United States)

    Nelson, Derek; Stieglitz, John D; Cox, Georgina K; Heuer, Rachael M; Benetti, Daniel D; Grosell, Martin; Crossley, Dane A

    2017-10-01

    Aerobic exercise capacity is dependent on the cardiorespiratory system's ability to supply oxygen at a rate that meets energetic demands. In teleost fish crude oil exposure, with the associated polycyclic aromatic hydrocarbons (PAH's), reduces exercise performance and this has been hypothesized to be due to compromised cardiovascular function. In this study, we test this hypothesis by simultaneously measuring cardiovascular performance, oxygen consumption, and swim performance in a pelagic teleost, the cobia (Rachycentron canadum). Metabolic rate increased over 300% in both groups during the swim trial but as the fish approached the critical swim speed (U crit ) MO 2 was 12% lower in the oil exposed fish. Further, stroke volume was initially 35% lower while heart rate was 15% higher in the oil exposed compared to control fish. Our findings suggested, while aspects of cardiovascular and metabolic function are altered by oil exposure, additional studies are needed to further understand the homeostatic mechanisms that may sustain cardiovascular function at higher exercise intensities in cobia. Copyright © 2017. Published by Elsevier Inc.

  12. Isolation and characterization of pathogenic Vibrio alginolyticus from sea cage cultured cobia (Rachycentron canadum (Linnaeus 1766)) in India.

    Science.gov (United States)

    Rameshkumar, P; Nazar, A K A; Pradeep, M A; Kalidas, C; Jayakumar, R; Tamilmani, G; Sakthivel, M; Samal, A K; Sirajudeen, S; Venkatesan, V; Nazeera, B M

    2017-11-01

    Mass mortalities of cobia, Rachycentron canadum, sub-adults occurred during August 2013 in cage culture in the Gulf of Mannar, Mandapam Tamil Nadu, India. The epizootic of disease was started with typical classical clinical signs followed by acute mortality. Grossly, severe haemorrhage and congestion were observed in the gastric mucosa. The abdomen was distended with peritoneal fluid. The heart revealed haemopericardium and fibrinous pericardium. Histologically, the gastric mucosa showed severe erosion and necrosis. Haemorrhagic pericarditis and an increased size of the melano macrophage centre (MMC) in the tail kidney were other histopathological changes. Vibrio sp. was isolated from the gastric lesions and heart blood swab of moribund fishes and it was found to be virulent to the cobia fingerlings. After the challenge, the same bacterium could be re-isolated from moribund fingerlings. The 16S ribosomal RNA of the isolate was amplified and blast analysis of the sequence confirmed that the pathogen was Vibrio alginolyticus. The confirmation was also correlated with its cultural, biochemical and pathomorphological changes. This is the second report and the first incidence of epizootics with severe pathological lesions in cultured cobia in India. The study throws light on the pathology of vibriosis. By practising cage farm management measures, occurrences of infection may be prevented. The epizootics of vibriosis caused serious economic losses to farmers. Natural blooms of the pathogen can be prevented by sea cage management measures such as, changing the inner net of the cages, changing the location of the cages to relatively clean water (about 50 m apart) from the affected site and providing shade over the cages while the water temperature rises. Supplementation of the feed with immunostimulants and mineral mixture may be practised to improve the immune response against infection. Early diagnosis and sea cage management measures may prevent occurrences of the

  13. [Characterization and transcriptional analysis of a new CC chemokine associated with innate imimune response in cobia (Rachycentron canadum)].

    Science.gov (United States)

    Su, Y; Feng, J; Sun, X; Guo, Z; Xu, L; Jiang, J

    2013-01-01

    Chemokines are small, secreted cytokine peptides, known principally for their ability to induce migration and activation of leukocyte populations under both pathological and physiological conditions. On the basis of previously constructed express sequence tags (ESTs) of the head kidney and spleen cDNA library of the perciform marine fish Rachycentron canadum (common name cobia). We used bi-directional rapid amplification of cDNA ends (RACE) and obtained a full-length cDNA of a new CC chemokine gene (designated RcCC3). The RcCC3 putative peptide exhibits sequence similarity to the group of CCL19/21/25 CC chemokines. The reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used in transcript expression studies of RcCC3. We examined the constitutive expression of the transcripts in 12 tissues of non-stressed cobia; RcCC3 transcripts were detected in all tissues examined, with the highest expression in gill and liver, following by head kidney, kidney, spleen, skin, intestine, muscle, stomach, heart, blood and brain. Transcript expression of RcCC3 was examined in immune-related organs, including head kidney, spleen and liver, following intraperitoneal injection of phosphate-buffered saline control, polyriboinosinic polyribocytidylic acid (poly(I:C)) and formalin-killed Vibrio carchariae (bacterial vaccine). The transcripts in these tissues were quickly up-regulated by the injection of poly(I:C) and bacterial vaccine at early time points, although with different expression profiles. These results indicate RcCC3 represents an important component of innate immunity in cobia.

  14. Effect of previous ascorbic acid treatment on the fatty acid profile of cobia (Rachycentron canadum fillets during frozen storage

    Directory of Open Access Journals (Sweden)

    Aftabsavar, Y.

    2012-03-01

    Full Text Available The present research focuses on the nutritional value of the lipid retention associated with frozen cobia (Rachycentron canadum. The effect of a previous soaking in an aqueous ascorbic acid (AA solution on the fatty acid profile of fish fillets during a further frozen storage period (–18 °C was investigated. Two different AA concentrations were tested (0.25% and 0.50% and compared to control conditions. As a result of the frozen storage period (up to 6 months, marked decreases were found in the contents of fatty acid groups such as monounsaturated, polyunsaturated and n-3 polyunsaturated, as well as in the n-3/n-6 ratio. However, a preserving effect on such fatty acid parameters could be observed resulting from the previous AA treatment, which was greater when applying the 0.50% AA concentration. Assessment of the polyene index indicated an increased lipid oxidation development during the frozen storage time; this increase was partially inhibited by the previous AA soaking.Este estudio se centra en el valor nutricional lipídico de cobia (Rachycentron canadum congelada. Para ello, se investiga el efecto que un tratamiento previo con ácido ascórbico (AA puede tener sobre el perfil de ácidos grasos de filete de pescado durante su conservación en congelación (–18 °C; seis meses. Se aplicaron dos concentraciones de AA (0.25% y 0.50% que fueron comparadas con muestras control. Como resultado de la conservación en congelación, se observó un descenso importante en grupos de ácidos grasos monoinsaturados, poliinsaturados y poliinsaturados de las serie n-3, así como en la relación n-3/n-6. Sin embargo, el tratamiento previo con AA produjo un efecto protector en estos parámetros, siendo mayor al aplicar AA en la concentración superior. La medida del índice de polienos reflejó un incremento de la oxidación lipídica durante la conservación en congelación; este incremento fue parcialmente inhibido como resultado del tratamiento

  15. Cloning of peroxisome proliferators activated receptors in the cobia (Rachycentron canadum) and their expression at different life-cycle stages under cage aquaculture.

    Science.gov (United States)

    Tsai, Mei-Ling; Chen, Houng-Yung; Tseng, Mei-Cheuh; Chang, Rey-Chang

    2008-12-01

    We present the cDNA sequences and tissue mRNA expression of peroxisome proliferator-activated receptor (PPAR) alpha, beta and gamma isotypes in the cobia (Rachycentron canadum), a warm water pelagic fish that is becoming a fish of choice for offshore cage farming. RT-PCR and real-time PCR showed that PPARalpha mRNA predominated in red muscle, heart and liver whereas PPARbeta was expressed mainly in liver and pyloric caeca. In contrast, PPARgamma transcripts were detected in all of the tissues examined, with the highest level occurring in visceral fat depot. Our 52-wk time-series investigation showed that while the mRNA expression of PPARgamma in the cobia was positively (P cobia.

  16. Structure and characteristics of acid and pepsin-solubilized collagens from the skin of cobia (Rachycentron canadum).

    Science.gov (United States)

    Zeng, Shaokui; Yin, Juanjuan; Yang, Shuqi; Zhang, Chaohua; Yang, Ping; Wu, Wenlong

    2012-12-01

    Acid-solubilized collagen (ASC) and pepsin-solubilized collagen (PSC) were extracted from the skin of cobia (Rachycentron canadum). The yields of ASC and PSC were 35.5% and 12.3%, respectively. Based on the protein patterns and carboxymethyl-cellulose chromatography, ASC and PSC were composed of α1α2α3 heterotrimers and were characterised as type I collagen with no disulfide bond. Their amounts of imino acids were 203 and 191 residues per 1000 residues, respectively. LC-MS/MS analysis demonstrated the high sequences similarities of ASC and PSC. Fourier transform infrared spectroscopy spectra showed that the amide I, II and III peaks of PSC were obtained at a lower wave number compared with ASC. The thermal denaturation temperatures of ASC and PSC, as measured by viscometry, were 34.62 and 33.97°C, respectively. The transition temperatures (T(max)) were 38.17 and 36.03°C, respectively, as determined by differential scanning calorimetry (DSC). Both collagens were soluble at acidic pH and below 2% (w/v) NaCl concentration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Immunomodulatory response of mice splenocytes induced by RcaL, a lectin isolated from cobia fish (Rachycentron canadum) serum.

    Science.gov (United States)

    Coriolano, Marília Cavalcanti; Silva, Cynarha Daysy Cardoso da; Melo, Cristiane Moutinho Lagos de; Bezerra, Ranilson de Souza; Santos, Athiê Jorge Guerra; Pereira, Valéria Rêgo Alves; Coelho, Luana Cassandra Breitenbach Barroso

    2012-11-01

    This work reports the isolation of a serum lectin from cobia fish (Rachycentron canadum) named RcaL. Immunomodulatory activity on mice splenocyte experimental cultures through cytotoxic assays and cytokine production were also performed. RcaL was obtained through precipitation with ammonium sulphate and affinity chromatography on a Concanavalin A-Sepharose 4B column. The ammonium sulphate fraction F3 showed the highest specific hemagglutinating activity and was applied to affinity chromatography. The lectin was eluted with methyl-α-D-mannopyranoside. RcaL showed highest affinity for methyl-α-D-mannopyranoside and D-mannose; eluted fractions of RcaL agglutinated rabbit erythrocytes (titre, 128(-1)) retained 66 % of chromatographed lectin activity, and the obtained purification factor was 1.14. Under reducing conditions, a polypeptide band of 19.2 kDa was revealed in sodium dodecyl sulphate polyacrylamide gel electrophoresis (PAGE). PAGE confirmed RcaL as an acidic protein revealed in a single band. Cytotoxic and immunomodulatory assays with RcaL in mice splenocyte cultures showed that the lectin was not cytotoxic and induced higher interferon gamma and nitric oxide production in splenocyte cultures. Purified RcaL induced preferential Th1 response, suggesting that it acts as an immunomodulatory compound.

  18. Effects of dietary phospholipid level in cobia (Rachycentron canadum) larvae: growth, survival, plasma lipids and enzymes of lipid metabolism.

    Science.gov (United States)

    Niu, J; Liu, Y J; Tian, L X; Mai, K S; Yang, H J; Ye, C X; Zhu, Y

    2008-03-01

    A study was conducted to determine the effects of dietary phospholipid (PL) levels in cobia (Rachycentron canadum) larvae with regard to growth, survival, plasma lipids and enzymes of lipid metabolism. Fish with an average weight of 0.4 g were fed diets containing four levels of PL (0, 20, 40 and 80 g kg(-1)dry matter: purity 97%) for 42 days. Final body weight (FBW), weight gain (WG) and survival ratio were highest in the 8% PL diet group and mortality was highest in PL-free diet group. We examined the activities of lipoprotein lipase (LPL) and hepatic lipase (HL) in liver, lecithin-cholesterolacyltransferase (LCAT) in plasma as well as plasma lipids and lipoprotein. LCAT activity showed a decrease of more than two-fold in PL-supplemented diet groups compared with the PL-free diet group. HL activity was highest in the 8% PL diet group and the other three groups showed no difference. LPL activity was significantly higher in the PL-supplemented diet groups than in the PL-free diet group. The dietary intervention significantly increased plasma phospholipids and total cholesterol (TC) levels, and the higher free cholesterol (FC) level contributed to the TC level. However, the fish fed PL exhibited a significantly decreased plasma triglyceride (TG) level. The lipoprotein fractions were also affected significantly by the PL. The PL-supplemented diet groups had significantly higher high-density lipoprotein (HDL) compared with the PL-free diet group, but showed a marked decrease in very low-density lipoprotein (VLDL). The results suggested that PL could modify plasma lipoprotein metabolism and lipid profile, and that the optimal dietary PL level may well exceed 80 g kg(-1) for cobia larvae according to growth and survival.

  19. Psettarium anthicum sp. n. (Digenea: Sanguinicolidae) from the heart of cobia Rachycentron canadum (Rachycentridae) in the northern Gulf of Mexico.

    Science.gov (United States)

    Bullard, Stephen A; Overstreet, Robin M

    2006-06-01

    Psettarium anthicum sp. n. (Digenea: Sanguinicolidae) infects the myocardium and atrial wall of the cobia Rachycentron canadum (Linnaeus, 1766) (Rachycentridae) in the northern Gulf of Mexico off Mississippi, USA. It is the first member of Psettarium Goto et Ozaki, 1930 reported from other than the Indian Ocean or Pacific Ocean and the second species of the genus reported from cobia. It differs from its congeners by the combination of having posterior caeca with lateral projections appearing as thorns in lateral view and the male pore anterior to the oötype. The species of Psettarium, P. japonicum (Goto et Ozaki, 1929) (type species), P. tropicum Manter, 1940, P. sebastodorum Holmes, 1971, P. rachycentri (Lebedev et Parukhin, 1972) comb. n. (syn. Psettarioides rachycentri Lebedev et Parukhin, 1972) and P. anthicum sp. n., differ from other sanguinicolids by the combination of having an elongate body with a sinistral posterolateral protuberance, minute, straight tegumental body spines in ventrolateral transverse rows, posterior caeca greater than seven time the anterior caeca length, the o6type near the posterior end of the body, a uterus primarily between the ovary and oötype and an oviduct and vitelline duct extending posteriad primarily between the uterus and dextral body margin. We emend Psettarium and provide a diagnostic key to the species. Psettarioides is regarded as a junior synonym of Psettarium because herein we return its type species, P. tropicum, to Psettarium. Regarding the three other sanguinicolids formerly of Psettarioides, we suspect that P. pseudupenei Lebedev et Parukhin, 1972 belongs to Psettarium but include it only tentatively pending an examination of type or other material; we tentatively place P. kurochkini Parukhin, 1976 in Cardicola Short, 1952; and we designate P. grandis (Lebedev et Mamaev, 1968) as incertae sedis pending examination of type or other appropriate material.

  20. Structurally Complex Organization of Repetitive DNAs in the Genome of Cobia (Rachycentron canadum).

    Science.gov (United States)

    Costa, Gideão W W F; Cioffi, Marcelo de B; Bertollo, Luiz A C; Molina, Wagner F

    2015-06-01

    Repetitive DNAs comprise the largest fraction of the eukaryotic genome. They include microsatellites or simple sequence repeats (SSRs), which play an important role in the chromosome differentiation among fishes. Rachycentron canadum is the only representative of the family Rachycentridae. This species has been focused on several multidisciplinary studies in view of its important potential for marine fish farming. In the present study, distinct classes of repetitive DNAs, with emphasis on SSRs, were mapped in the chromosomes of this species to improve the knowledge of its genome organization. Microsatellites exhibited a diversified distribution, both dispersed in euchromatin and clustered in the heterochromatin. The multilocus location of SSRs strengthened the heterochromatin heterogeneity in this species, as suggested by some previous studies. The colocalization of SSRs with retrotransposons and transposons pointed to a close evolutionary relationship between these repetitive sequences. A number of heterochromatic regions highlighted a greater complex organization than previously supposed, harboring a diversity of repetitive elements. In this sense, there was also evidence of colocalization of active genetic regions and different classes of repetitive DNAs in a common heterochromatic region, which offers a potential opportunity for further researches regarding the interaction of these distinct fractions in fish genomes.

  1. The impact of lysine and arginine ratios in plant-based protein diets on appetite, growth performance and gene expression of brain neuropeptide Y (NPY) and cholecystokinin (CCK) in juvenile cobia (Rachycentron canadum)

    OpenAIRE

    Nguyen, Minh Van

    2013-01-01

    Aquaculture of cobia, Rachycentron canadum is hampered by lack of good feeding protocols and nutritionally optimized diets. Studies on the role of appetite and feeding behavior regulating neuropeptides in cobia have not been pursued to date. The current study initially assessed the impact of plant-based protein diets with different lysine (L) to arginine (A) ratios on appetite and feed intake, feed efficiencies, growth performance, and the deposition of protein and lipid in juv...

  2. Effect of dietary vitamin C on the growth performance and innate immunity of juvenile cobia (Rachycentron canadum).

    Science.gov (United States)

    Zhou, Qicun; Wang, Ligai; Wang, Hualang; Xie, Fengjun; Wang, Tuo

    2012-06-01

    This study was conducted to evaluate the effects of dietary vitamin C on growth performance, hematologic parameters and innate immune responses in juvenile cobia, Rachycentron canadum. Seven practical diets were formulated to contain 0.0 (as the basal diet), 13.6, 27.2, 54.4, 96.6, 193.4 and 386.5 mg ascorbic acid equivalent kg(-1) diet. Each diet was fed to triplicate groups of juvenile cobia with initial body weight of 5.5 g in 500-L cylindrical fiberglass tank. The results of 8 weeks feeding trial showed that typical vitamin C-deficient signs such as spinal deformation and body nigrescence were observed in the fish fed the basal diet. Fish fed the basal diet had significantly lower weight gain, specific growth rate (SGR), protein efficiency ratio (PER) and feed efficiency (FE) than those fed the diets supplemented with vitamin C, but no significant differences were observed among diets supplemented with vitamin C. However, survival rate was significantly affected by the dietary vitamin C levels, fish fed the basal diet had lower survival rate than those fed the diets supplemented with vitamin C. The ascorbic acid concentration in liver was correlated positively with the dietary vitamin C levels, however, the thiobarbituric acid reactive substances (TBARS) concentrations in liver was not significantly affected by the dietary vitamin C levels, although, fish fed the basal diet had the highest TBARS values among all treatments. The activities of serum lysozyme, superoxide dismutase (SOD), alkaline phophatase (AKP) and total immunoglobulin (Ig) were significantly influenced by the dietary vitamin C levels, fish fed the basal diet had lower lysozyme, SOD, AKP and total Ig than those fed diets supplemented with vitamin C. The serum glucose and triglyceride concentrations were significantly affected by the dietary vitamin C levels. Fish fed the basal diet had lower red blood cell and hemoglobin values than those fed the vitamin C supplemented diets. The challenge

  3. Evaluating the protective efficacy of antigen combinations against Photobacterium damselae ssp. piscicida infections in cobia, Rachycentron canadum L.

    Science.gov (United States)

    Ho, L-P; Chang, C-J; Liu, H-C; Yang, H-L; Lin, J H-Y

    2014-01-01

    Cobia, Rachycentron canadum L., is a very important aquatic fish that faces the risk of infection with the bacterial pathogen Photobacterium damselae ssp. piscicida, and there are few protective approaches available that use multiple antigens. In the present study, potent bivalent antigens from P. damselae ssp. piscicida showed more efficient protection than did single antigens used in isolation. In preparations of three antigens that included recombinant heat shock protein 60 (rHSP60), recombinant α-enolase (rENOLASE) and recombinant glyceraldehyde-3-phosphate dehydrogenase (rGAPDH), we analysed the doses that elicited the best immune responses and found that this occurred at a total of 30 μg of antigen per fish. Subsequently, vaccination of fish with rHSP60, rENOLASE and rGAPDH achieved 46.9, 52 and 25% relative per cent survival (RPS), respectively. In addition, bivalent subunit vaccines--combination I (rHSP60 + rENOLASE), combination II (rENOLASE + rGAPDH) and combination III (rHSP60 + rGAPDH)--were administered and the RPS in these groups (65.6, 64.0 and 48.4%, respectively), was higher than that achieved with single-antigen administration. Finally, in combination IV, the trivalent vaccine rHSP60 + rENOLASE + rGAPDH, the RPS was 1.6%. Taken together, our results suggest that combinations of two antigens may achieve a better efficiency than monovalent or trivalent antigens, and this may provide new insights into pathogen prevention strategies. © 2013 John Wiley & Sons Ltd.

  4. Effects of medicinal herbs "Plantago asiatica", "Houttuynia cordata" and "Mentha haplocalyx" on non-specific immune responses of cobia (Rachycentron canadum).

    Science.gov (United States)

    Wu, Yu-Sheng; Chen, Yin-Yu; Ueng, Pien-Sheng; Nan, Fan-Hua

    2016-11-01

    This study investigated the effects of orally administered Plantago asiatica, Houttuynia cordata, and Mentha haplocalyx on the growth and nonspecific immune responses of cobia (Rachycentron canadum). The nonspecific immune parameters assessed were weight gain, feed conversion ratio, superoxide anion (O 2 - ) production, superoxide dismutase (SOD) activity, phagocytic rate, phagocytic index, lysozyme activity, serum albumin and globulin, and albumin:globulin (A/G) ratio. The growth experiment indicated that 6-week dietary treatments did not significantly affect on the growth of cobia. Nonspecific immune responses showed that O 2 - production, SOD and lysozyme activity, and phagocytosis were significantly increased after the oral administration of P. asiatica and H. cordata, and the serum albumin:globulin ratio (A/G) gradually decreased. In this study, treatment of the Mentha haplocalyx on the cobia didn't present with the inducing of the phagocytosis ability compared with the treatment of P. asiatica and H. cordata. We suggest that oral administration of the 10 g/kg or 20 g/kg of the P. asiatica and H. cordata is exactly inducing the phagocytosis, ROS production, lysozyme activity and SOD production in the cobia. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. First record of Tuxophorus caligodes (Siphonostomatoida, Tuxophoridae) in sea-farmed cobia, Rachycentron canadum, in Brazil.

    Science.gov (United States)

    da Silva, Ana Carolina; de Moraes, Julieta Rodini Engrácia; Antonucci, Antonio Mataresio; Shimada, Marina Tie; Takemoto, Ricardo Massato; Engrácia Filho, Jair Rodini; de Moraes, Flávio Ruas

    2012-01-01

    The cobia is the only representative of the Rachycentridae family and, because of its zootechnical qualities, production of this fish has been implemented in several countries, such as the United States, Mexico and Brazil. Tuxophorus caligodes is a widespread parasite of marine fish worldwide. For the present report, 15 juvenile cobias were collected from net cages on a fish farm in Ilhabela, state of São Paulo, Brazil, in the winter of 2011. The fish were sacrificed by means of cerebral concussion, and then weighed (280 ± 70.5 g) and measured (27 ± 1.97 cm). After external examination under a stereomicroscope, ectoparasites present on the body surface were collected, fixed and processed for identification. Out of the 15 fish examined, two were parasitized with Tuxophorus caligodes, thus indicating a prevalence of 13.3%. This is the first report of Tuxophorus caligodes in cobias in Brazil.

  6. Identification and expression analysis of cobia (Rachycentron canadum) Toll-like receptor 9 gene.

    Science.gov (United States)

    Byadgi, Omkar; Puteri, Dinda; Lee, Yan-Horn; Lee, Jai-Wei; Cheng, Ta-Chih

    2014-02-01

    Cobia culture is hindered by bacterial infection (Photobacterium damselae subsp. piscicida) and in order to study the effect of P. damselae subsp. piscicida challenge and CpG ODN stimulation on cobia Toll like receptor 9 (RCTLR9), we used PCR to clone RCTLR9 gene and qRT-PCR to quantify gene expression. The results indicated that RCTLR9 cDNA contains 3141 bp. It encodes 1047 amino acids containing 16 typical structures of leucine-rich repeats (LRRs) including an LRRTYP, LRRCT and a motif involved in PAMP binding was identified at position 240-253 amino acid. Broad expression of RCTLR9 was found in larval, juvenile and adult stages irrespective of the tissues. In larval stage, RCTLR9 mRNA expression decreased at 5 d and then increased at 10 dph. At juvenile stage cobia, the expression was significantly high (p Cobia challenged with P. damselae subsp. piscicida showed significant increase in RCTLR9 expression at 24 h post challenge in intestine, spleen and liver, while in kidney the expression was peak at 12 h and later it decreased at 24 h. The highest expression was 40 fold increase in spleen and the lowest expression was ∼3.6 fold increase in liver. Cobia stimulated with CpG oligonucleotides showed that the induction of these genes was CpG ODN type and time dependent. In spleen and liver, CpG ODNs 1668 and 2006 injected group showed high expression of RCTLR9, IL-1β, chemokine CC compared to other groups. Meanwhile, CpG ODN 2006 has induced high expression of IgM. The CpG ODNs 2395 have induced significant high expression of Mx in spleen and liver. These results demonstrates the potential of using CpG ODN to enhance cobia resistance to P. damselae subsp. piscicida infection and use as an adjuvant in vaccine development. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Textural and biochemical properties of cobia (Rachycentron canadum) sashimi tenderised with the ultrasonic water bath.

    Science.gov (United States)

    Chang, Hung-Chia; Wong, Ren-Xian

    2012-06-01

    The present study investigated the tenderisation effects ultrasound processing (UT) on farmed cobia sashimi. Age-treated cobia trunk muscles (AT) were used as the control. The pH, total volatile base nitrogen, trimethylamine nitrogen, thiobarbituric acid reactive substances, ATP catabolism components, K 1 value, and texture were evaluated. The texture of AT sashimi reached the optimal firmness range with 8.53N at day 7. However, AT samples could not be served raw after day 7 because of their poor freshness indexes, including a TVBN value of 18.53g/100g, a TMAN value of 3.25mg/100g, and a TBARS value 0.983MDAmg/100g. Moreover, the K 1 value of AT sashimi was 20.21% at day 5. UT was employed to efficiently tenderise cobia sashimi with an initial firmness of 9.70-7.82N after 90min of treatment. The results of this study indicate that UT accelerates the biochemical reaction rate, as evidenced by the increases in the TVBN, TMAN, and TBARS contents; however, these values were very low. The results of this study could provide basic information for the development of a novel ultrasonic tenderisation technique in raw seafood designed for restaurants and consumers. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Effects of dietary corn gluten meal on growth performance and protein metabolism in relation to IGF-I and TOR gene expression of juvenile cobia ( Rachycentron canadum)

    Science.gov (United States)

    Luo, Yiwen; Ai, Qinghui; Mai, Kangsen; Zhang, Wenbing; Xu, Wei; Zhang, Yanjiao; Liufu, Zhiguo

    2013-09-01

    A growth experiment was conducted on cobia ( Rachycentron canadum, initial weight 108.2 g ± 3.0 g) to investigate the effects of dietary corn gluten meal (CGM) levels on the fish growth, whole body composition and protein metabolism in relation to specific gene expression. Five isonitrogenous (crude protein 45%) and isoenergetic (gross energy 20 kJ g-1) practical diets were formulated by replacing 0% (the control), 17.5%, 35.0%, 52.5%, and 70.0% of fish meal (FM) protein with CGM protein. No significant differences were observed in the survival, feed intake (FI), specific growth rate (SGR), feed efficiency (FE) and protein productive value (PPV) among fish fed diets with 0%, 17.5%, 35.0%, and 52.5% of CGM protein. However, these indices were significantly lower in fish fed the diet with 70.0% of CGM protein than those in fish fed the control diet ( P cobia. The present results might be useful for developing cost effective and sustainable cobia dietary formulations.

  9. Different ratios of docosahexaenoic and eicosapentaenoic acids do not alter growth, nucleic acid and fatty acids of juvenile cobia (Rachycentron canadum).

    Science.gov (United States)

    Xu, Youqing; Ding, Zhaokun; Zhang, Haizhu; Liu, Liang; Wang, Shuqi; Gorge, John

    2009-12-01

    An experiment was performed to study the effect of different ratios of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on the growth, nucleic acid and fatty acids of cobia (Rachycentron canadum) juveniles. The juveniles were fed for 8 weeks using seven treatment diets (D-1-D-7) with the same amount of DHA and EPA (1.50 +/- 0.1% of dried diet), but varying ratios of DHA to EPA (0.90, 1.10, 1.30, 1.50, 1.70, 1.90, 2.10, respectively) and a control diet (D-0, DHA + EPA = 0.8% of dried diet, DHA/EPA = 1.30). At the end of the experiment, the mean body weight (BW) of juveniles fed D-0-D-7 increased significantly (from 6.86 +/- 1.64 in the week 0 to 58.52 +/- 16.45 g at the end of week 8, P cobia juveniles fed D-0-D-7 were significantly higher at the end of 8-week experiment than initially (P cobia juveniles increased with their growth and appeared an obvious positive relationship, especially in the muscle, based on regression analysis. The mean lipid content increased significantly in the liver (from 29.82 +/- 0.99 to 37.47 +/- 3.25% totally) and muscle (from 6.74 +/- 0.25 to 10.63 +/- 0.23% totally) of cobia juveniles (P 0.05). In the muscle and liver of juveniles, EPA decreased with its reduction in the diet; DHA, DHA/EPA ratio and poly unsaturated fatty acids (PUFAs) generally increased with their increment in the diet. The conclusion was drawn that the growth, nucleic acid and fatty acids of cobia juveniles were not significantly affected by different DHA/EPA ratios in our experiments.

  10. Taurine supplementation of plant derived protein and n-3 fatty acids are critical for optimal growth and development of cobia, Rachycentron canadum.

    Science.gov (United States)

    Watson, Aaron M; Barrows, Frederic T; Place, Allen R

    2013-09-01

    We examined growth performance and the lipid content in juvenile cobia, Rachycentron canadum, fed a taurine supplemented (1.5 %), plant protein based diet with two fish oil replacements. The first fish oil replacement was a thraustochytrid meal (TM + SOY) plus soybean oil (~9 % CL) and the second was a canola oil supplemented with the essential fatty acids (EFA) docosahexaenoic acid (DHA) and arachidonic acid (ARA) (~8 % CL). The diet using the thraustochytrid meal plus soybean oil performed equivalently to the fish oil diet; both resulting in significantly higher growth rates, lower feed conversion ratios, and higher survival than the supplemented canola oil diet, even though all three diets were similar in overall energy and met known protein and lipid requirements for cobia. The poor performance of the canola oil diet was attributed to insufficient addition of EFA in the supplemented canola oil source. Increasing levels of EFA in the supplemented canola oil above 0.5 g EFA kg(-1) would likely improve results with cobia. When fish fed either of the fish oil replacement diets were switched to the fish oil control diet, fatty acid profiles of the fillets were observed to transition toward that of the fish oil diet and could be predicted based on a standard dilution model. Based on these findings, a formulated diet for cobia can be produced without fish products providing 100 % survivorship, specific growth rates greater than 2.45 and feed conversion ratios less than 1.5, as long as taurine is added and EFA levels are above 0.5 g EFA kg(-1).

  11. Toxic effects of two sources of dietborne cadmium on the juvenile cobia, Rachycentron canadum L. and tissue-specific accumulation of related minerals.

    Science.gov (United States)

    Liu, Kang; Chi, Shuyan; Liu, Hongyu; Dong, Xiaohui; Yang, Qihui; Zhang, Shuang; Tan, Beiping

    2015-08-01

    In the present study, juvenile cobia, Rachycentron canadum L. were fed diets contaminated by two different sources of cadmium: squid viscera meal (SVM-Cd, organic form) and cadmium chloride (CdCl2-Cd, inorganic form). The Cd concentrations in fish diet were approximate 3.0, 5.0 and 10.0mg Cd kg(-1) for both inorganic and organic forms. In the control diet (0.312mg Cd kg(-1) diet, Cd mainly come from fish meal), no cadmium was added. The experiment lasted for 16 weeks and a statistically significant inverse relationship was observed between specific growth rate (SGR) and the concentration of dietary Cd. The SGR of cobia fed a diet with SVM-Cd increased at the lowest doses and decreased with the increasing level of dietary SVM. Fish fed diet contaminated SVM-Cd had significantly higher SGR than those fed diets contaminated CdCl2-Cd among the high Cd level diets treatments. The dietary Cd levels also significantly affected the survival rate of the fish. Among the hematological characteristics and plasma constituents, glutamic-pyruvic transaminase activities and alkaline phosphatase activities in serum and liver increased and hepatic superoxide dismutase activity decreased with the increasing dietary Cd levels. The cobia fed diet contaminated by high level of CdCl2-Cd had significantly higher ALP activity than cobia fed diet contaminated by high level of SVM-Cd. The results from these studies indicate no differences in toxicity response to dietborne SVM-Cd and CdCl2-Cd at a low level of Cd. However, at a higher level, cobia was more sensitive to dietborne CdCl2-Cd than SVM-Cd. Based on quadratic regression of SGR, The Cd concentrations was 3.617mg kg(-1) in the optimal diet, Cd source was SVM (126mg Cd kg(-1) in SVM) which stimulate the growth of cobia and the added level was determined to be 26.7g kg(-1) diet in the present study. Cd accumulations in the kidney of cobia fed both types of Cd were higher than other tissues, and the order of Cd accumulation in tissues

  12. Effects of supplemental coated or crystalline methionine in low-fishmeal diet on the growth performance and body composition of juvenile cobia Rachycentron canadum (Linnaeus)

    Science.gov (United States)

    Chi, Shuyan; Tan, Beiping; Dong, Xiaohui; Yang, Qihui; Liu, Hongyu

    2014-11-01

    We evaluated the effects of supplemental coated and crystalline methionine (Met) on the growth performance and feed utilization of juvenile cobia ( Rachycentron canadum Linnaeus) in a 60-d feeding trial. Fish groups were fed one of six isonitrogenous and isolipidic diets: 1) fishmeal control; 2) un-supplemented experimental (low-fish-meal diet deficient in Met); or 3) one of four Met diets supplemented with crystalline L-Met, cellulose-acetate-phthalate coated L-Met, acrylic-resin coated L-Met, or tripalmitin-polyvinyl alcohol coated L-Met. The test diets were fed to triplicate groups of cobia (initial body weight 5.40±0.07 g) twice a day. The weight gain and specific growth rate of the fish fed the RES diet were highest among the Met-supplemented groups and were 23.64% and 7.99%, respectively, higher than those of the fish fed with the un-supplemented experimental diet ( Pcobia.

  13. Bovine pancreatic trypsin inhibitor immobilized onto sepharose as a new strategy to purify a thermostable alkaline peptidase from cobia (Rachycentron canadum) processing waste.

    Science.gov (United States)

    França, Renata Cristina da Penha; Assis, Caio Rodrigo Dias; Santos, Juliana Ferreira; Torquato, Ricardo José Soares; Tanaka, Aparecida Sadae; Hirata, Izaura Yoshico; Assis, Diego Magno; Juliano, Maria Aparecida; Cavalli, Ronaldo Olivera; Carvalho, Luiz Bezerra de; Bezerra, Ranilson Souza

    2016-10-15

    A thermostable alkaline peptidase was purified from the processing waste of cobia (Rachycentron canadum) using bovine pancreatic trypsin inhibitor (BPTI) immobilized onto Sepharose. The purified enzyme had an apparent molecular mass of 24kDa by both sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and mass spectrometry. Its optimal temperature and pH were 50°C and 8.5, respectively. The enzyme was thermostable until 55°C and its activity was strongly inhibited by the classic trypsin inhibitors N-ρ-tosyl-l-lysine chloromethyl ketone (TLCK) and benzamidine. BPTI column allowed at least 15 assays without loss of efficacy. The purified enzyme was identified as a trypsin and the N-terminal amino acid sequence of this trypsin was IVGGYECTPHSQAHQVSLNSGYHFC, which was highly homologous to trypsin from cold water fish species. Using Nα-benzoyl-dl-arginine ρ-nitroanilide hydrochloride (BApNA) as substrate, the apparent km value of the purified trypsin was 0.38mM, kcat value was 3.14s(-1), and kcat/km was 8.26s(-1)mM(-1). The catalytic proficiency of the purified enzyme was 2.75×10(12)M(-1) showing higher affinity for the substrate at the transition state than other fish trypsin. The activation energy (AE) of the BApNA hydrolysis catalyzed by this enzyme was estimated to be 11.93kcalmol(-1) while the resulting rate enhancement of this reaction was found to be approximately in a range from 10(9) to 10(10)-fold evidencing its efficiency in comparison to other trypsin. This new purification strategy showed to be appropriate to obtain an alkaline peptidase from cobia processing waste with high purification degree. According with N-terminal homology and kinetic parameters, R. canadum trypsin may gathers desirable properties of psychrophilic and thermostable enzymes. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Toxic effects of two sources of dietborne cadmium on the juvenile cobia, Rachycentron canadum L. and tissue-specific accumulation of related minerals

    International Nuclear Information System (INIS)

    Liu, Kang; Chi, Shuyan; Liu, Hongyu; Dong, Xiaohui; Yang, Qihui; Zhang, Shuang; Tan, Beiping

    2015-01-01

    Highlights: • CdCl 2 –Cd showed a higher toxicity than SVM-Cd for cobia. • Cd accumulation in cobia fed diets contaminated SVM-Cd was higher than in cobia fed diets contaminated CdCl 2 –Cd. • Cd accumulation in tissues of cobia fed both types of Cd was kidney > liver > intestine > gill muscle. • Dietborne Cd decreased the Fe concentration in kidney and liver, Ca concentrations in vertebra and scale. - Abstract: In the present study, juvenile cobia, Rachycentron canadum L. were fed diets contaminated by two different sources of cadmium: squid viscera meal (SVM-Cd, organic form) and cadmium chloride (CdCl 2 –Cd, inorganic form). The Cd concentrations in fish diet were approximate 3.0, 5.0 and 10.0 mg Cd kg −1 for both inorganic and organic forms. In the control diet (0.312 mg Cd kg −1 diet, Cd mainly come from fish meal), no cadmium was added. The experiment lasted for 16 weeks and a statistically significant inverse relationship was observed between specific growth rate (SGR) and the concentration of dietary Cd. The SGR of cobia fed a diet with SVM-Cd increased at the lowest doses and decreased with the increasing level of dietary SVM. Fish fed diet contaminated SVM-Cd had significantly higher SGR than those fed diets contaminated CdCl 2 –Cd among the high Cd level diets treatments. The dietary Cd levels also significantly affected the survival rate of the fish. Among the hematological characteristics and plasma constituents, glutamic-pyruvic transaminase activities and alkaline phosphatase activities in serum and liver increased and hepatic superoxide dismutase activity decreased with the increasing dietary Cd levels. The cobia fed diet contaminated by high level of CdCl 2 –Cd had significantly higher ALP activity than cobia fed diet contaminated by high level of SVM-Cd. The results from these studies indicate no differences in toxicity response to dietborne SVM-Cd and CdCl 2 –Cd at a low level of Cd. However, at a higher level, cobia was

  15. Toxic effects of two sources of dietborne cadmium on the juvenile cobia, Rachycentron canadum L. and tissue-specific accumulation of related minerals

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Kang [Laboratory of Aquatic Animal Nutrition and Feed, College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong (China); Guangdong Yuehai Feed Group Co., Ltd., Zhanjiang, Guangdong (China); Chi, Shuyan; Liu, Hongyu; Dong, Xiaohui; Yang, Qihui; Zhang, Shuang [Laboratory of Aquatic Animal Nutrition and Feed, College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong (China); Tan, Beiping, E-mail: bptan@126.com [Laboratory of Aquatic Animal Nutrition and Feed, College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong (China)

    2015-08-15

    Highlights: • CdCl{sub 2}–Cd showed a higher toxicity than SVM-Cd for cobia. • Cd accumulation in cobia fed diets contaminated SVM-Cd was higher than in cobia fed diets contaminated CdCl{sub 2}–Cd. • Cd accumulation in tissues of cobia fed both types of Cd was kidney > liver > intestine > gill muscle. • Dietborne Cd decreased the Fe concentration in kidney and liver, Ca concentrations in vertebra and scale. - Abstract: In the present study, juvenile cobia, Rachycentron canadum L. were fed diets contaminated by two different sources of cadmium: squid viscera meal (SVM-Cd, organic form) and cadmium chloride (CdCl{sub 2}–Cd, inorganic form). The Cd concentrations in fish diet were approximate 3.0, 5.0 and 10.0 mg Cd kg{sup −1} for both inorganic and organic forms. In the control diet (0.312 mg Cd kg{sup −1} diet, Cd mainly come from fish meal), no cadmium was added. The experiment lasted for 16 weeks and a statistically significant inverse relationship was observed between specific growth rate (SGR) and the concentration of dietary Cd. The SGR of cobia fed a diet with SVM-Cd increased at the lowest doses and decreased with the increasing level of dietary SVM. Fish fed diet contaminated SVM-Cd had significantly higher SGR than those fed diets contaminated CdCl{sub 2}–Cd among the high Cd level diets treatments. The dietary Cd levels also significantly affected the survival rate of the fish. Among the hematological characteristics and plasma constituents, glutamic-pyruvic transaminase activities and alkaline phosphatase activities in serum and liver increased and hepatic superoxide dismutase activity decreased with the increasing dietary Cd levels. The cobia fed diet contaminated by high level of CdCl{sub 2}–Cd had significantly higher ALP activity than cobia fed diet contaminated by high level of SVM-Cd. The results from these studies indicate no differences in toxicity response to dietborne SVM-Cd and CdCl{sub 2}–Cd at a low level of Cd

  16. De novo transcriptome analysis of immune response on cobia (Rachycentron canadum) infected with Photobacterium damselae subsp. piscicida revealed inhibition of complement components and involvement of MyD88-independent pathway.

    Science.gov (United States)

    Tran, Hung Bao; Lee, Yen-Hung; Guo, Jiin-Ju; Cheng, Ta-Chih

    2018-06-01

    Cobia, Rachycentron canadum, one of the most important aquatic species in Taiwan, has suffered heavy losses from Photobacterium damselae subsp. piscicida, which is the causal agent of photobacteriosis. In this study, the transcriptomic profiles of livers and spleens from Pdp-infected and non-infected cobia were obtained for the first time by Illumina-based paired-end sequencing method with a focus on immune-related genes. In total, 164,882 high quality unigenes were obtained in four libraries. Following Pdp infection, 7302 differentially expressed unigenes from liver and 8600 differentially expressed unigenes from spleen were identified. Twenty-seven of the differently expressed genes were further validated by RT-qPCR (average correlation coefficient 0.839, p-value cobia. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. A mannose-specific tetrameric lectin with mitogenic and antibacterial activities from the ovary of a teleost, the cobia (Rachycentron canadum).

    Science.gov (United States)

    Ngai, Patrick H K; Ng, T B

    2007-02-01

    A tetrameric lectin, with hemagglutinating activity toward rabbit erythrocytes and with specificity toward D-mannosamine and D(+)-mannose, was isolated from the ovaries of a teleost, the cobia Rachycentron canadum. The isolation protocol comprised ion exchange chromatography on CM-cellulose and Q-Sepharose, ion exchange chromatography by fast protein liquid chromatography (FPLC) on Mono Q, and finally gel filtration by FPLC on Superose 12. The lectin was adsorbed on all ion exchangers used. It exhibited a molecular mass of 180 kDa in gel filtration on Superose 12 and a single 45-kDa band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that it is a tetrameric protein. The hemagglutinating activity of the lectin was stable up to 40 degrees C and between pH 4 and pH 10. All hemagglutinating activity disappeared at 60 degrees C and at pH 1 and pH 13. The hemagglutinating activity was doubled in the presence of 0.1 microM FeCl3. The lectin exerted antibacterial activity against Escherichia coli with 50% inhibition at 250 microg. There was no antifungal activity toward Coprinus comatus, Fusarium oxysporum, Mycosphaerella arachidicola, and Rhizoctonia solani at a dose of 300 microg. The lectin exhibited maximal mitogenic response from mouse splenocytes at a concentration of 14 microM.

  18. Effects of dietary chitosan and Bacillus subtilis on the growth performance, non-specific immunity and disease resistance of cobia, Rachycentron canadum.

    Science.gov (United States)

    Geng, Xu; Dong, Xiao-Hui; Tan, Bei-Ping; Yang, Qi-Hui; Chi, Shu-Yan; Liu, Hong-Yu; Liu, Xian-Qin

    2011-09-01

    The present study was performed to investigate the effects of various levels of dietary Bacillus subtilis and chitosan on the growth performance, non-specific immunity and protection against Vibrio harveyi infection in cobia, Rachycentron canadum. Fish were fed with the control diet and six different experimental diets containing three graded levels of B. subtilis at 2 × 10(10) CFU g(-1) (0.0, 1.0, 2.0 g kg(-1) diet) for each of two levels of chitosan (3.0 and 6.0 g kg(-1) diet). The results of 8 weeks feeding trial showed that the survival rate ranged from 81.3% to 84.0% with no significant difference (P > 0.05). The SGR (%) in the fish fed with dietary treatments was significantly higher than that of the control fish except diet 6 group with 2.0 g kg(-1)B. subtilis and 3.0 g kg(-1) chitosan. The serum lysozyme activities were significantly higher in 6.0 g kg(-1) chitosan groups and no significant differences were observed among B. subtilis levels. The serum ACP activities were significantly higher in 3.0 g kg(-1) chitosan groups at 0.0 and 1.0 g kg(-1)B. subtilis levels; at low chitosan level, the cobia fed diets with 1.0 g kg(-1)B. subtilis had significantly higher serum ACP activity, but at high chitosan level, the cobia fed diets with 2.0 g kg(-1)B. subtilis had significantly higher serum ACP activity. The phagocytosis and respiratory burst activity in the fish fed with dietary treatments was significantly higher than that of the control fish except diet 3 group with 6.0 g kg(-1) chitosan. Moreover, fish fed the diet containing 2.0 g kg(-1)B. subtilis and 6.0 g kg(-1) chitosan had significantly higher post-challenge survival on the 7th day following V. harveyi infection and post-challenge survival showed clearly the synergistic effect of chitosan and B. subtilis. Based on these results, the combination of 1.0 g kg(-1)B. subtilis and 6.0 g kg(-1) chitosan is optimal for the growth, innate immunity and disease resistance of cobia with an 8-week oral

  19. First record of Tuxophorus caligodes (Siphonostomatoida, Tuxophoridae in sea-farmed cobia, Rachycentron canadum, in Brazil Primeiro relato de Tuxophorus caligodes (Siphonostomatoida, Tuxophoridae em cultivo de cobias, Rachycentron canadum, no Brasil

    Directory of Open Access Journals (Sweden)

    Ana Carolina da Silva

    2012-12-01

    Full Text Available The cobia is the only representative of the Rachycentridae family and, because of its zootechnical qualities, production of this fish has been implemented in several countries, such as the United States, Mexico and Brazil. Tuxophorus caligodes is a widespread parasite of marine fish worldwide. For the present report, 15 juvenile cobias were collected from net cages on a fish farm in Ilhabela, state of São Paulo, Brazil, in the winter of 2011. The fish were sacrificed by means of cerebral concussion, and then weighed (280 ± 70.5 g and measured (27 ± 1.97 cm. After external examination under a stereomicroscope, ectoparasites present on the body surface were collected, fixed and processed for identification. Out of the 15 fish examined, two were parasitized with Tuxophorus caligodes, thus indicating a prevalence of 13.3%. This is the first report of Tuxophorus caligodes in cobias in Brazil.O cobia é o único representante da família Rachycentridae e, devido às suas qualidades zootécnicas, a produção desse peixe tem sido implementada em vários países, tais como os Estados Unidos, México e Brasil. Tuxophorus caligodes é um parasito de peixes marinhos amplamente distribuído no mundo. Para o presente relato, 15 juvenis de cobias foram coletados de tanques-rede, em uma fazenda marinha em Ilhabela, Estado de São Paulo, Brasil, no inverno de 2011. Os peixes foram sujeitos à eutanásia por meio de concussão cerebral, pesados (280 ± 70,5 g e medidos (27 ± 1,97 cm. Após exame externo sob um estereomicroscópio, os ectoparasitos presentes na superfície do corpo foram coletados, fixados e processados para identificação. Dos 15 peixes examinados, dois apresentavam-se parasitados indicando a prevalência de 13,3%. Esse é o primeiro relato de Tuxophorus caligodes em cobias no Brasil.

  20. Exuberant granulation tissue response associated with Neobenedenia sp. (Monogenea: Capsalidae) infestation in two cobia, Rachycentron canadum (Linnaeus).

    Science.gov (United States)

    Hurley-Sanders, J; Harms, C; Christiansen, E; Clarke, E; Law, J

    2016-03-01

    Monogenean parasite infestations are common in captive marine teleosts, and are generally found on the skin and gills. This report describes an unusual pathological presentation of exuberant granulation tissue of the gills, suspected to be related to Neobenedenia infestation in two cobia housed together at a North Carolina aquarium. © 2015 John Wiley & Sons Ltd.

  1. The effect of TLR9 agonist CpG oligodeoxynucleotides on the intestinal immune response of cobia (Rachycentron canadum).

    Science.gov (United States)

    Byadgi, Omkar; Puteri, Dinda; Lee, Jai-Wei; Chang, Tsung-Chou; Lee, Yan-Horn; Chu, Chun-Yen; Cheng, Ta-Chih

    2014-01-01

    Cytosine-guanine oligodeoxynucleotide (CpG ODN) motifs of bacterial DNA are recognized through toll-like receptor 9 (TLR9) and are potent activators of innate immunity. However, the interaction between TLR9 and CpG ODN in aquatic species has not been well characterized. Hence, cobia TLR9 isoform B (RCTLR9B) was cloned and its expression and induction in intestine were investigated. RCTLR9B cDNA consists of 3113bp encoding 1009 amino acids containing three regions, leucine rich repeats, transmembrane domain, and toll/interleukin-1 receptor (TIR) domain. Intraperitoneal injection of CpG ODN 2395 upregulated RCTLR9 A and B and MyD88 and also induced the expressions of Mx, chemokine CC, and interleukin IL-1 β . Cobia intraperitoneally injected with CpG ODN 1668 and 2395 had increased survival rates after challenge with Photobacterium damselae subsp. piscicida. In addition, formulation of CpG ODN with formalin-killed bacteria (FKB) and aluminum hydroxide gel significantly increased expressions of RCTLR9 A (50 folds) and B (30 folds) isoforms at 10 dpi (CpG ODN 1668) and MyD88 (21 folds) at 6 dpv (CpG ODN 2395). Subsequently, IL-1 β increased at 6 dpv in 1668 group. No histopathological damage and inflammatory responses were observed in the injected cobia. Altogether, these results facilitate CpG ODNs as an adjuvant to increase bacterial disease resistance and efficacy of vaccines in cobia.

  2. The Effect of TLR9 Agonist CpG Oligodeoxynucleotides on the Intestinal Immune Response of Cobia (Rachycentron canadum

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    Omkar Byadgi

    2014-01-01

    Full Text Available Cytosine-guanine oligodeoxynucleotide (CpG ODN motifs of bacterial DNA are recognized through toll-like receptor 9 (TLR9 and are potent activators of innate immunity. However, the interaction between TLR9 and CpG ODN in aquatic species has not been well characterized. Hence, cobia TLR9 isoform B (RCTLR9B was cloned and its expression and induction in intestine were investigated. RCTLR9B cDNA consists of 3113bp encoding 1009 amino acids containing three regions, leucine rich repeats, transmembrane domain, and toll/interleukin-1 receptor (TIR domain. Intraperitoneal injection of CpG ODN 2395 upregulated RCTLR9 A and B and MyD88 and also induced the expressions of Mx, chemokine CC, and interleukin IL-1β. Cobia intraperitoneally injected with CpG ODN 1668 and 2395 had increased survival rates after challenge with Photobacterium damselae subsp. piscicida. In addition, formulation of CpG ODN with formalin-killed bacteria (FKB and aluminum hydroxide gel significantly increased expressions of RCTLR9 A (50 folds and B (30 folds isoforms at 10 dpi (CpG ODN 1668 and MyD88 (21 folds at 6 dpv (CpG ODN 2395. Subsequently, IL-1β increased at 6 dpv in 1668 group. No histopathological damage and inflammatory responses were observed in the injected cobia. Altogether, these results facilitate CpG ODNs as an adjuvant to increase bacterial disease resistance and efficacy of vaccines in cobia.

  3. Angiotensin I converting enzyme inhibitory activity and antihypertensive effect in spontaneously hypertensive rats of cobia (Rachycentron canadum) head papain hydrolysate.

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    Yang, Ping; Jiang, Yuchuan; Hong, Pengzhi; Cao, Wenhong

    2013-06-01

    Cobia head protein hydrolysate (CHPH) with angiotensin I converting enzyme (ACE) inhibitory activity was prepared with papain. The 3 kDa ultrafiltration filtrate CHPH-IV of the hydrolysate exerted a potent ACE inhibitory activity with IC50 being 0.24 mg/mL. The fractions with molecular weight located between 1749 Da and 173 Da represented up 66.96% of CHPH-IV, and those between 494 Da and 173 Da represented up 31.37% of CHPH-IV. It was found that the ACE inhibitory activity of CHPH-IV was intensified from IC50 0.24 mg/mL to 0.17 mg/mL after incubation with gastrointestinal proteases. The CHPH-IV significantly decreased the systolic blood pressure in a dose-dependent manner after oral administration to spontaneously hypertensive rats (SHR) at dose of 150 mg/kg, 600 mg/kg and 1200 mg/kg body weight. These results suggested that CHPH-IV from cobia head protein hydrolysate by papain could serve as a source of peptides with antihypertensive activity in functional food industry.

  4. Thyroid gland development in Rachycentron canadum during early life stages.

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    Otero, Adriana P S; Rodrigues, Ricardo V; Sampaio, Luís A; Romano, Luis A; Tesser, Marcelo B

    2014-09-01

    The aim of this study was to describe the ontogeny of thyroid follicles in cobia Rachycentron canadum. Larvae were sampled daily (n=15 - 20) from hatching until 15 dah (days after hatching). Following, larvae were sampled every two days by 28 dah; a new sample was taken at 53 dah. The samples were dehydrated, embedded in Paraplast, and sections of 3 µm were dewaxed, rehydrated and stained with HE and PAS. A single follicle was already present 1 dah and three follicles were found 8 dah. The number of follicles increased up to 19 on 53 dah. The diameter of follicles and follicular cell height were lower 1 dah (6.83 ± 1.00 and 4.6 ± 0.01 µm), but increased from 8 dah (24.03 ± 0.46 µm e 6.43 ± 0.46 µm). From 8 dah, the presence of reabsorption vesicles was observed in the colloid and from the 19 dah some follicles did not present colloid. The early thyroid follicle appearance in cobia larvae as well as the high quantity of follicles without colloid and/or with vesicles even after the metamorphosis, might be the explanation of the fast growth of the cobia.

  5. Thyroid gland development in Rachycentron canadum during early life stages

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    ADRIANA P.S. OTERO

    2014-09-01

    Full Text Available The aim of this study was to describe the ontogeny of thyroid follicles in cobia Rachycentron canadum. Larvae were sampled daily (n=15 - 20 from hatching until 15 dah (days after hatching. Following, larvae were sampled every two days by 28 dah; a new sample was taken at 53 dah. The samples were dehydrated, embedded in Paraplast, and sections of 3 µm were dewaxed, rehydrated and stained with HE and PAS. A single follicle was already present 1 dah and three follicles were found 8 dah. The number of follicles increased up to 19 on 53 dah. The diameter of follicles and follicular cell height were lower 1 dah (6.83 ± 1.00 and 4.6 ± 0.01 µm, but increased from 8 dah (24.03 ± 0.46 µm e 6.43 ± 0.46 µm. From 8 dah, the presence of reabsorption vesicles was observed in the colloid and from the 19 dah some follicles did not present colloid. The early thyroid follicle appearance in cobia larvae as well as the high quantity of follicles without colloid and/or with vesicles even after the metamorphosis, might be the explanation of the fast growth of the cobia.

  6. Identification and expression analysis of two pro-inflammatory cytokines, TNF-α and IL-8, in cobia (Rachycentron canadum L.) in response to Streptococcus dysgalactiae infection.

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    Nguyen, Thuy Thi Thu; Nguyen, Hai Trong; Wang, Pei-Chyi; Chen, Shih-Chu

    2017-08-01

    Tumor necrosis factor-alpha (TNF-α) and interleukin-8 (IL-8/CXCL8) play pivotal roles in mediating inflammatory responses to invading pathogens. In this study, we identified and analyzed expressions of cobia TNF-α and IL-8 during Streptococcus dysgalactiae infection. The cloned cDNA transcript of cobia TNF-α comprised of 1281 base pairs (bp), with a 774 bp open reading frame (ORF) encoding 257 amino acids. The deduced amino acid sequence of cobia TNF-α showed a close relationship (84% similarity) with TNF-α of yellowtail amberjack. The cloned IL-8 cDNA sequence was 828 bp long, including a 300-bp ORF encoding 99 amino acids. The deduced amino acid sequence of cobia IL-8 shared 90% identity with IL-8 of striped trumpeter. Cobia challenged with a virulent S. dysgalactiae strain displayed an early significant up-regulation of TNF-α and IL-8 in head kidney, liver, and spleen. Notably, IL-8 expression level increased dramatically in the liver at the severe stage of infection (72 h). In conclusion, a better understanding of TNF-α and IL-8 allows more detailed investigation of immune responses in cobia and furthers study on controlling the infectious disease caused by S. dysgalactiae. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Response to ocean acidification in larvae of a large tropical marine fish, Rachycentron canadum.

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    Bignami, Sean; Sponaugle, Su; Cowen, Robert K

    2013-04-01

    Currently, ocean acidification is occurring at a faster rate than at any time in the last 300 million years, posing an ecological challenge to marine organisms globally. There is a critical need to understand the effects of acidification on the vulnerable larval stages of marine fishes, as there is potential for large ecological and economic impacts on fish populations and the human economies that rely on them. We expand upon the narrow taxonomic scope found in the literature today, which overlooks many life history characteristics of harvested species, by reporting on the larvae of Rachycentron canadum (cobia), a large, highly mobile, pelagic-spawning, widely distributed species with a life history and fishery value contrasting other species studied to date. We raised larval cobia through the first 3 weeks of ontogeny under conditions of predicted future ocean acidification to determine effects on somatic growth, development, otolith formation, swimming ability, and swimming activity. Cobia exhibited resistance to treatment effects on growth, development, swimming ability, and swimming activity at 800 and 2100 μatm pCO2 . However, these scenarios resulted in a significant increase in otolith size (up to 25% larger area) at the lowest pCO2 levels reported to date, as well as the first report of significantly wider daily otolith growth increments. When raised under more extreme scenarios of 3500 and 5400 μatm pCO2 , cobia exhibited significantly reduced size-at-age (up to 25% smaller) and a 2-3 days developmental delay. The robust nature of cobia may be due to the naturally variable environmental conditions this species currently encounters throughout ontogeny in coastal environments, which may lead to an increased acclimatization ability even during long-term exposure to stressors. © 2012 Blackwell Publishing Ltd.

  8. Production of cobia in recirculating systems

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    Only limited information exists with respect to rearing juvenile cobia Rachycentron canadum to stocker and marketable sizes using recirculating aquaculture systems (RAS). To investigate this topic, two rearing trials were conducted using commercial scale RAS. In Trial 1, juvenile cobia (29 g) we...

  9. Production of cobia in recirculating aquaculture systems

    Science.gov (United States)

    Interest in cobia Rachycentron canadum aquaculture in the US has increased greatly in the last decade due to their excellent consumer appeal, extremely rapid growth rates, and the observed success of rearing this species in Taiwan and other southeastern Asian countries. Because most cobia are grown...

  10. Reanalysis and revision of the complete mitochondrial genome of Rachycentron canadum (Teleostei, Perciformes, Rachycentridae).

    Science.gov (United States)

    Musika, Jidapa; Khongchatee, Adison; Phinchongsakuldit, Jaros

    2014-08-01

    The complete mitochondrial genome of cobia, Rachycentron canadum, was reanalyzed and revised. The genome is 18,008 bp in length, containing 13 protein-coding genes, 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a control region or displacement loop (D-loop). The gene arrangement is identical to that observed in most vertebrates. Base composition on the heavy strand is 30.14% A, 25.22% C, 15.80% G and 28.84% T. The D-loop region exhibits an A + T rich pattern, containing short tandem repeats of TATATACATGG, TATATGCACAA and TATATGCACGG. The mitochondrial genome studied differs from the previously published genome in two segments; the control region to 12S and ND5 to tRNA(Glu). The 12S sequence also differs from those published in the databases. Phylogeny analyses revealed that the differences could be due to errors in sequence assembly and/or sample misidentification of the previous studies.

  11. Cobia (Rachycentron canadum hatchery-to-market aquaculture technology: recent advances at the University of Miami Experimental Hatchery (UMEH Tecnologia da criação de beijupirá (Rachycentron canadum: recentes avanços do Laboratório de Larvicultura Experimental da Universidade de MIAMI (UMEH

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    Daniel Benetti

    2010-07-01

    Full Text Available Among warm-water marine fishes, cobia is one of the best aquaculture candidate species in the world. Currently there are commercial culture operations in several Asian countries and the industry has started developing elsewhere, including the Western Central Atlantic region. Significant research has been conducted at the University of Miami's Aquaculture Program / University of Miami Experimental Hatchery (UMEH during the last eight years, involving research to develop and optimize advanced technology to demonstrate the viability of raising hatchery-reared cobia in collaboration with the private sector. This paper reviews some of this recent advances for the development of Hatchery-to-Market Aquaculture Technology for commercial production of cobia.Dentre os peixes marinhos de águas quentes, o bijupirá é um dos grandes candidatos para a aquacultura no mundo. Atualmente, existem operações comerciais em vários países Asiáticos e a indústria iniciou suas operações em outros locais, incluindo a região do Atlântico Central. Pesquisas têm sido realizadas no "University of Miami's Aquaculture Program / University of Miami Experimental Hatchery (UMEH" durante os últimos oito anos envolvendo o desenvolvimento e otimização de tecnologia avançada para demonstrar a viabilidade da criação de bijupirá com colaboração com o setor privado. Este artigo revisa alguns destes avanços recentes para o desenvolvimento da tecnologia da larvicultura para o mercado para a produção comercial de bijupirá.

  12. Chromosome Mapping of Repetitive Sequences in Rachycentron canadum (Perciformes: Rachycentridae: Implications for Karyotypic Evolution and Perspectives for Biotechnological Uses

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    Uedson Pereira Jacobina

    2011-01-01

    Full Text Available The cobia, Rachycentron canadum, a species of marine fish, has been increasingly used in aquaculture worldwide. It is the only member of the family Rachycentridae (Perciformes showing wide geographic distribution and phylogenetic patterns still not fully understood. In this study, the species was cytogenetically analyzed by different methodologies, including Ag-NOR and chromomycin A3 (CMA3/DAPI staining, C-banding, early replication banding (RGB, and in situ fluorescent hybridization with probes for 18S and 5S ribosomal genes and for telomeric sequences (TTAGGGn. The results obtained allow a detailed chromosomal characterization of the Atlantic population. The chromosome diversification found in the karyotype of the cobia is apparently related to pericentric inversions, the main mechanism associated to the karyotypic evolution of Perciformes. The differential heterochromatin replication patterns found were in part associated to functional genes. Despite maintaining conservative chromosomal characteristics in relation to the basal pattern established for Perciformes, some chromosome pairs in the analyzed population exhibit markers that may be important for cytotaxonomic, population, and biodiversity studies as well as for monitoring the species in question.

  13. Evaluation of commercial marine fish feeds for production of juvenile cobia in recirculating aquaculture systems

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    The effect of feeding three commercially available diets manufactured by three U.S. feed companies on production characteristics and body composition of juvenile cobia Rachycentron canadum reared in recirculating aquaculture systems (RAS) was evaluated in a 57 d growth trial. Juvenile cobia (26.7 +...

  14. Production characteristics and body composition of juvenile cobia fed three different commercial diets in recirculating aquaculture systems

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    The effect of feeding three commercial diets on production characteristics and body composition of juvenile cobia Rachycentron canadum reared using recirculating aquaculture systems (RAS) was evaluated in a 56 d growth trial. Juvenile cobia (29.2 +/= 0.7 g, mean weight +/= SE) were stocked into thr...

  15. Trial finds biomass harvest of cobia unaffected by stocking density in RAS

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    Cobia, Rachycentron canadum, were reared for 119 days from 322 g to market size in production-scale recirculating aquaculture systems at in-tank densities of 10, 20, or 30 kg/m3. No significant differences were detected in growth rate, survival, feed efficiency or body composition. This study is t...

  16. Production of juvenile and sub-adult cobia in recirculating aquaculture systems

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    Cobia Rachycentron canadum is a large migratory pelagic finfish species that is distributed worldwide in tropical, subtropical, and warm temperate seas except the Mediterranean and the central and eastern Pacific. Despite its large size, commonly exceeding 23 kg at maturity, and excellent food qual...

  17. A Redescription of Serrasentis sagittifer (Rhadinorhynchidae: Serrasentinae) from Rachycentron canadum (Rachycentridae) with Comments on its Biology and its Relationship to Other Species of Serrasentis.

    Science.gov (United States)

    Barton, Diane P; Smales, Lesley; Morgan, Jess A T

    2018-04-01

    Adult and cystacanth forms of the acanthocephalan Serrasentis sagittifer from Australian coastal waters are redescribed and verified as the same species using both molecular and morphological data. This study provides the baseline 18S rDNA, 28S rDNA, and cox1 sequence data to serve as genetic barcode for S. sagittifer. The validity of the currently recognized species of Serrasentis is discussed. The most recently described species are junior synonyms of either Serrasentis nadakali or S. sagittifer, and a number of species are species inquirenda. When using morphological characters to distinguish the species of Serrasentis, consideration needs to be given to the maturity of the specimens, since the trunk elongates and the number and distribution of the ventral combs changes as worms mature, although the proboscis armature itself does not change. A simple key to assist in the identification of species of Serrasentis is provided. Adult S. sagittifer appear to be highly host specific to the cobia, Rachycentron canadum, in northern Australian waters, whereas cystacanths have been reported from a wide range of fish species. The relationship between host length and number of cystacanths shows that most paratenic infections are acquired as young fish, most likely via a crustacean intermediate host.

  18. Effect of culture density on production characteristics and body composition of market size cobia reared from juveniles in recirculating aquaculture systems

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    Interest regarding cobia Rachycentron canadum aquaculture in the US has increased greatly in the last decade due to their excellent consumer appeal, extremely rapid growth rates, and the observed success of rearing this species in Taiwan and other southeastern Asian countries. Because the principal...

  19. PARASITES, DISEASES AND DEFORMITIES OF COBIA

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    Ewen McLean

    2008-01-01

    Full Text Available Cobia, Rachycentron canadum, is the only member of the family Rachycentridae (Order Perciformes and as a warm–water fish is to be found in tropical and subtropical waters. The species has been reported in eastern Mediterranean waters and it is likely that in this particular case, cobia are lessespian. Cobia has been farmed in Taiwan since the early 1990s and today nascent cobia aquaculture operations operate throughout South East and Eastern Asia, in Gulf of Mexico and Caribbean Sea as well as in the United States. Many other nations are presently considering adopting cobia as a new species for aquaculture. Production by aquaculture experienced a 7000–fold increase from 1995 to 2005. The increased interest in the species has evolved due in large part to its many excellent characteristics which include good growth, with production of 6 kg live weight fish being possible over a year–long production cycle. Cobia are accepting of pond, net pens and recirculation–based culture; their fillet quality is high and meat delectable; They readily take formulated feeds and respond well to alternate proteins in their diets. Like other species new to aquaculture however, enlarged farming activities have been accompanied by increased incidence of commonly–encountered and emerging diseases. As an aid to current and potential producers as well as researchers, the following provides an overview of the published literature on cobia diseases, parasites and physical deformities.

  20. A novel agent (Endozoicomonas elysicola) responsible for epitheliocystis in cobia Rachycentrum canadum larvae.

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    Mendoza, Mabel; Güiza, Linda; Martinez, Ximena; Caraballo, Xenia; Rojas, Jaime; Aranguren, Luis Fernando; Salazar, Marcela

    2013-09-24

    Aquaculture of cobia has gained popularity in the last decade, and this species is now farmed in several countries in Latin America and Asia. Despite recent improvement in production techniques that allowed the expansion of the industry, little is known about the diseases that affect cobia during the larviculture stage. In this article we investigated the cause of mass mortalities occurring 13-20 d post-hatching in 3 cycles of cobia larviculture. Wet mounts from diseased larvae gills revealed the presence of cyst-like basophilic inclusions. DNA from the cysts was extracted and PCR amplified using the 16S rRNA gene universal primers for prokaryotes. The amplified products were sequenced and analyzed using BLAST, finding a similarity of 99% with Endozoicomonas elysicola, a Gram-negative bacterium. Confirmation of E. elysicola was conducted by designing a specific probe for in situ hybridization. Specific primers were also designed for diagnostic purposes. This is the first report of epitheliocystis in cobia larvae and also the first report of E. elysicola as an epitheliocystis-causing agent.

  1. Predicting the effects of copper on local population decline of 2 marine organisms, cobia fish and whiteleg shrimp, based on avoidance response.

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    Araújo, Cristiano V M; Cedeño-Macías, Luís A; Vera-Vera, Victoria C; Salvatierra, David; Rodríguez, Elizabeth N V; Zambrano, Ufredo; Kuri, Samir

    2016-02-01

    The present study focuses on avoidance response to predict population decline of the marine fish Rachycentron canadum (cobia) and larvae of the estuarine shrimp Litopenaeus vannamei (whiteleg shrimp). Avoidance of approximately 60% was recorded for the cobia fry exposed to 1.0 mg Cu/L, 1.60 mg Cu/L, and 1.80 mg Cu/L. For the shrimp larvae, avoidance was approximately 80% for all Cu concentrations. The population decline of cobia fry was conditioned by avoidance in lower concentrations. However, in higher concentrations mortality begins to play an important role. The displacement toward uncontaminated habitats might determine shrimp population decline. A Cu-contaminated environment can determine the habitat selection of both species and, therefore, their local population decline. © 2015 SETAC.

  2. CLONING OF cDNA FOR RACHYCENTRON CANADUM GROWTH HORMONE AND ITS EXPRESSION IN PROKARYOCYTE%军曹鱼(Rachycentron canadum)生长激素基因cDNA的克隆和原核表达

    Institute of Scientific and Technical Information of China (English)

    郝羽; 邓思平; 刘丽; 刘楚吾

    2011-01-01

    运用同源克隆方法,从军曹鱼脑垂体中分离了生长激素基因(GH)的全长cDNA。结果表明,该基因cDNA全长862bp,含615bp的开放阅读框(ORF),编码204个氨基酸;其中包括22个氨基酸的信号肽和182个氨基酸的成熟肽。采用T-A克隆构建pMD18-T-CoGH重组质粒,测序正确后经Nde I和Xho I双酶切获得CoGH片段,插入表达载体pET-28a,获得pET-CoGH重组质粒并在表达宿主菌Escherichia coli BL21(DE3)中用IPTG诱导表达。SDS—PAGE电泳显示在22.4kDa处有特异性的蛋白条带出现,Western—blotting检测表明已经成功表达了融合蛋白,该蛋白主要以非可溶性的包涵体形式存在于菌体沉淀中。%The full length eDNA encoding growth hormone of Rachycentron canadum was amplified and cloned from total RNA isolated from pituitary gland by RT-PCR. The sequence was 862 nucleotides long, including.an ORF of 615 base pairs. The encoded protein contains 204 amino acids, comprising a 22 amino acids signal peptide and a 182 amino acids mature protein. The resulting cDNA sequence was undergone sequence analysis and subcloned into expression vector pET-28a between Nde land Xho I restriction sites and expressed in Escherichia coli BL21(DE3) cells. SDS-PAGE and Western-blotting analysis showed that the expressed protein accumulated as inclusion bodies and the molecular weight of expressed fusion protein was 22.4kDa.

  3. Parâmetros hematológicos e alterações histopatológicas em bijupirá (Rachycentron canadum Linnaeus, 1766 com amyloodiniose

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    Bartira Guerra-Santos

    2012-11-01

    Full Text Available O objetivo do trabalho foi descrever os parâmetros hematológicos e as alterações histopatológicas em bijupirás infectados por Amyloodinium ocellatum. Um grupo de 27 peixes foi anestesiado para coleta de amostras de sangue e eutanasiados para coleta de muco e fragmentos de tecido cutâneo e branquial. Foram avaliadas a prevalência e a intensidade parasitária da infecção, assim como os valores de parâmetros hematológicos e alterações histopatológicas. A prevalência parasitária nas brânquias foi de 100% e no muco foi de 80,8% e as intensidades parasitárias médias foram de 683,5 nas brânquias, e 67,1 no muco cutâneo. Os valores médios dos parâmetros hematológicos foram: eritrócitos 4,3x10(6µL; VG 26%; VGM 64,2fL; proteína plasmática 5,8mg/dL; trombócitos 5,2 x10³/µL e leucócitos 3,6 x10³/µL. Além disso, foram verificadas hiperplasia do epitélio respiratório acompanhada de fusão lamelar, descolamento do epitélio, dilatação do seio venoso, formação de aneurisma, ruptura do epitélio lamelar, hemorragia, necrose, reação inflamatória linfocítica. O parasito foi observado nas lamelas branquiais, o VMA variou do grau discreto ao severo e o IAH foi de 76,8. A pesquisa assume importância por se tratar dos primeiros estudos em Rachycentron canadum, um peixe que se destaca com potencial ao cultivo.

  4. Feed intake and brain neuropeptide Y (NPY) and cholecystokinin (CCK) gene expression in juvenile cobia fed plant-based protein diets with different lysine to arginine ratios.

    Science.gov (United States)

    Nguyen, Minh Van; Jordal, Ann-Elise Olderbakk; Espe, Marit; Buttle, Louise; Lai, Hung Van; Rønnestad, Ivar

    2013-07-01

    Cobia (Rachycentron canadum, Actinopterygii, Perciformes;10.5±0.1g) were fed to satiation with three plant-based protein test diets with different lysine (L) to arginine (A) ratios (LL/A, 0.8; BL/A, 1.1; and HL/A, 1.8), using a commercial diet as control for six weeks. The test diets contained 730 g kg(-1) plant ingredients with 505-529 g protein, 90.2-93.9 g lipid kg(-1) dry matter; control diet contained 550 g protein and 95 g lipid kg(-1) dry matter. Periprandial expression of brain NPY and CCK (npy and cck) was measured twice (weeks 1 and 6). At week one, npy levels were higher in pre-feeding than postfeeding cobia for all diets, except LL/A. At week six, npy levels in pre-feeding were higher than in postfeeding cobia for all diets. cck in pre-feeding cobia did not differ from that in postfeeding for all diets, at either time point. Cobia fed LL/A had lower feed intake (FI) than cobia fed BL/A and control diet, but no clear correlations between dietary L/A ratio and FI, growth and expression of npy and cck were detected. The data suggest that NPY serves as an orexigenic factor, but further studies are necessary to describe links between dietary L/A and regulation of appetite and FI in cobia. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Developmental expression of the G protein-coupled receptor 54 and three GnRH mRNAs in the teleost fish cobia.

    Science.gov (United States)

    Mohamed, J Shaik; Benninghoff, Abby D; Holt, G Joan; Khan, Izhar A

    2007-02-01

    The cDNAs of the G protein-coupled receptor 54 (GPR54) and three prepro-gonadotropin-releasing hormones, GnRH-I (seabream GnRH), GnRH-II (chicken GnRH-II), and GnRH-III (salmon GnRH) were isolated and cloned from the brain of the teleost fish cobia, Rachycentron canadum. The cobia GPR54 cDNA was 95 and 51-56% identical to those of tilapia and mammalian models respectively. The GnRH cDNA sequences of cobia showed strong identities to those of tilapia, Atlantic croaker, red drum, and the seabass and seabream species. The real-time quantitative RT-PCR methods allowed detection of all three GnRH mRNAs on the first day after hatching (DAH). The GnRH-I mRNA levels, which were the lowest among the three GnRHs, increased gradually with two distinct peaks in larvae at 3 and 4 DAH. On the other hand, GnRH-II and GnRH-III mRNAs were significantly higher in larvae at 2 and 6 DAH compared with those on the preceding days. In addition, significant peaks of all the three GnRH mRNAs were observed in the brains of 26-day-old fish. The finding of higher GnRH-I and GnRH-II mRNAs in males than females at 153 DAH may be related to early puberty observed during the first year in laboratory-reared male cobia. Moreover, this study demonstrates for the first time the expression of GPR54 mRNA during larval development in a vertebrate species. The concomitant expression patterns of GPR54 and GnRH mRNAs during different stages of larval and juvenile developments, and during early puberty in male cobia suggest a potential relationship between GPR54 and multiple GnRHs during these stages of development consistent with the role of GPR54 in controlling GnRH release in mammals. The increase in GPR54 and GnRH mRNAs observed during early puberty in cobia is consistent with a similar change reported in pubertal rats. This finding together with the localization of GPR54 mRNAs on GnRH neurons in fish and mammals suggests that the GPR54-GnRH interactions may be conserved in different vertebrate groups.

  6. Transposable elements in fish chromosomes: a study in the marine cobia species.

    Science.gov (United States)

    Costa, G W W F; Cioffi, M B; Bertollo, L A C; Molina, W F

    2013-01-01

    Rachycentron canadum, a unique representative of the Rachycentridae family, has been the subject of considerable biotechnological interest due to its potential use in marine fish farming. This species has undergone extensive research concerning the location of genes and multigene families on its chromosomes. Although most of the genome of some organisms is composed of repeated DNA sequences, aspects of the origin and dispersion of these elements are still largely unknown. The physical mapping of repetitive sequences on the chromosomes of R. canadum proved to be relevant for evolutionary and applied purposes. Therefore, here, we present the mapping by fluorescence in situ hybridization of the transposable element (TE) Tol2, the non-LTR retrotransposons Rex1 and Rex3, together with the 18S and 5S rRNA genes in the chromosome of this species. The Tol2 TE, belonging to the family of hAT transposons, is homogeneously distributed in the euchromatic regions of the chromosomes but with huge colocalization with the 18S rDNA sites. The hybridization signals for Rex1 and Rex3 revealed a semi-arbitrary distribution pattern, presenting differentiated dispersion in euchromatic and heterochromatic regions. Rex1 elements are associated preferentially in heterochromatic regions, while Rex3 shows a scarce distribution in the euchromatic regions of the chromosomes. The colocalization of TEs with 18S and 5S rDNA revealed complex chromosomal regions of repetitive sequences. In addition, the nonpreferential distribution of Rex1 and Rex3 in all heterochromatic regions, as well as the preferential distribution of the Tol2 transposon associated with 18S rDNA sequences, reveals a distinct pattern of organization of TEs in the genome of this species. A heterogeneous chromosomal colonization of TEs may confer different evolutionary rates to the heterochromatic regions of this species.

  7. New data on the morphology of Iheringascaris inquies (Linton, 1901) (Nematoda: Anisakidae), a specific parasite of the marine fish Rachycentron canadum (Linnaeus), as revealed by SEM

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Yost, J.; de Buron, I.

    2012-01-01

    Roč. 59, č. 4 (2012), s. 315-318 ISSN 0015-5683 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : fish host * marine fish * morphology * North America * parasitic nematode Subject RIV: EA - Cell Biology Impact factor: 2.515, year: 2012 http://folia.paru.cas.cz/pdfs/showpdf.php?pdf=22098

  8. Evidence of green fluorescent protein and growth hormone expression in red abalone (Haliotis rufescens larvae

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    Mancilla-Sánchez Edgar

    2017-02-01

    Full Text Available The red abalone Haliotis rufescens is a highly appreciated mollusk in the national and international markets. Due to its natural over-exploitation and low growth rate, several genetic improvements were made, however special efforts are needed to increase its production. This study presents transgenic abalone’s larvae expressing green fluorescent protein (GFP fused to Cobia (Rachycentron canadum Growth Hormone (GH using sperm media transgenesis technique (SMT, pAcGFP1-N vector under the control of cytomegalovirus (CMV promoter. Sperms were exposed to three voltages (0.5, 0.75 and 1.0 Kv using a micropulser electroporator (Bio-Rad®. The highest GFP-GH expression average (40% was obtained in abalone larvae at 0.75 v. GFP and GH transgenes were positively detected by PCR, western blot and confocal microscope, respectively.

  9. Effect of ions on the activity of brain acetylcholinesterase from tropical fish

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    Caio Rodrigo Dias Assis

    2015-07-01

    Full Text Available Objective: To investigate the effect of ions on brain acetylcholinesterase (AChE; EC 3.1.1.7 activities from economic important fish [pirarucu, Arapaima gigas; tambaqui, Colossoma macropomum; cobia, Rachycentron canadum (R. canadum and Nile tilapia, Oreochromis niloticus (O. niloticus] comparing with a commercial enzyme from electric eel [Electrophorus electricus (E. electricus]. Methods: The in vitro exposure was performed at concentrations ranging from 0.001 to 10 mmol/L (except for ethylene diamine tetraacetic acid; up to 150 mmol/L. Inhibition kinetics on R. canadum and O. niloticus were also observed through four methods (Michaelis-Menten, Lineweaver-Burk, Dixon and Cornish-Bowden plots in order to investigate the type of inhibition produced by some ions. Results: Hg 2+ , As 3+ , Cu 2+ , Zn 2+ , Cd 2+ caused inhibition in all the species under study. Ca 2+ , Mg 2+ and Mn 2+ induced slight activation in R. canadum enzyme while Pb 2+ , Ba 2+ , Fe 2+ , Li + inhibited the AChE from some of the analyzed species. The lowest IC 50 and Ki values were estimated for E. electricus AChE in presence of Hg 2+ , Pb 2+ , Zn 2+ . Under our experimental conditions, the results for R. canadum and O. niloticus, As 3+ , Cu 2+ , Cd 2+ , Pb 2+ and Zn 2+ showed a non- competitive/mixed-type inhibition, while Hg 2+ inhibited the enzyme in a mixed/competitive- like manner. Conclusions: E. electricus AChE activity was affected by ten of fifteen ions under study showing that this enzyme could undergo interference by these ions when used as pesticide biosensor in environmental analysis. This hindrance would be less relevant for the crude extracts.

  10. Distribution and accumulation of organotin species in seawater, sediments and organisms collected from a Taiwan mariculture area.

    Science.gov (United States)

    Liu, Li-Lian; Wang, Jih-Terng; Chung, Kuo-Nan; Leu, Ming-Yih; Meng, Pei-Jie

    2011-01-01

    The present study was undertaken to evaluate the distribution and accumulation of tributyltin (TBT) and triphenyltin (TPhT) in seawater, sediments and selected organisms from a cage mariculture area in southern Taiwan, Hsiao Liouchiou Island. Our results show that ΣOTs were found in concentrations as high as 196 ng/L in seawater collected from the sites in Pai-Sa harbor, and up 1040 ng/g dry wt. in sediments dredged from sites within Da-Fu harbor. Also, ΣOTs concentrations of 859 ng/g dry wt. were observed in the liver of cobia (Rachycentron canadum) from mariculture cages. As most published studies have focused on the acute toxicity and bioaccumulation of organotins in mussels, the effects of organotins on cobia and other marine fauna are still poorly understood. This study highlights the significance of ΣBTs accumulation in cobia, as well as in the sediments and seawater surrounding their culture facilities. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Ocean acidification alters the otoliths of a pantropical fish species with implications for sensory function.

    Science.gov (United States)

    Bignami, Sean; Enochs, Ian C; Manzello, Derek P; Sponaugle, Su; Cowen, Robert K

    2013-04-30

    Ocean acidification affects a wide diversity of marine organisms and is of particular concern for vulnerable larval stages critical to population replenishment and connectivity. Whereas it is well known that ocean acidification will negatively affect a range of calcareous taxa, the study of fishes is more limited in both depth of understanding and diversity of study species. We used new 3D microcomputed tomography to conduct in situ analysis of the impact of ocean acidification on otolith (ear stone) size and density of larval cobia (Rachycentron canadum), a large, economically important, pantropical fish species that shares many life history traits with a diversity of high-value, tropical pelagic fishes. We show that 2,100 μatm partial pressure of carbon dioxide (pCO2) significantly increased not only otolith size (up to 49% greater volume and 58% greater relative mass) but also otolith density (6% higher). Estimated relative mass in 800 μatm pCO2 treatments was 14% greater, and there was a similar but nonsignificant trend for otolith size. Using a modeling approach, we demonstrate that these changes could affect auditory sensitivity including a ∼50% increase in hearing range at 2,100 μatm pCO2, which may alter the perception of auditory information by larval cobia in a high-CO2 ocean. Our results indicate that ocean acidification has a graded effect on cobia otoliths, with the potential to substantially influence the dispersal, survival, and recruitment of a pelagic fish species. These results have important implications for population maintenance/replenishment, connectivity, and conservation efforts for other valuable fish stocks that are already being deleteriously impacted by overfishing.

  12. Avanços da maricultura na primeira década do século XXI: piscicultura e carcinocultura marinha Advances in mariculture on the first decade of the XXI century: marine fish and shrimp culture

    Directory of Open Access Journals (Sweden)

    Luís André Sampaio

    2010-07-01

    Full Text Available A piscicultura marinha é um setor pouco desenvolvido na maricultura brasileira. Por vários anos foi avaliado o potencial de cultivo de algumas espécies como o robalo-peva Centropomus parallelus e o linguado Paralichtys orbignyanus. Entretanto, somente a partir do investimento sobre o bijupirá Rachycentron canadum é que empresas privadas passaram a demonstrar maior interesse na atividade. Além dos sistemas tradicionais de piscicultura, o bijupirá pode ser criado em tanques-rede oceânicos. Esta espécie apresenta crescimento rápido, atingindo entre 4 e 8 kg em um ano de vida, e carne de excelente qualidade. A carcinocultura tem sido questionada por questões ambientais, uso de insumos como farinha e óleo de peixe e disseminação de doenças. A criação de camarões em sistemas sem renovação de água "ZEAH" (Zero Exchange, Aerobic, Heterotrophic Culture Systems ou cultivo em meio aos Bioflocos (BFT aplica métodos que minimizam estes problemas, contribuindo para uma maricultura mais saudável.Marine fish culture is still in its infancy in Brazil. For several years the snook Centropomus parallelus and the flounder Paralicithys orbignyanus were considered for aquaculture, but their commercial application has not yet been achieved. However, once technology for culture of cobia Rachycentron canadum became available, several private companies showed interest for marine fish culture. Besides traditional rearing technologes, cobia is suitable for open ocean culture in cages. This species shows fast growth rates, fish can achieve 4 or 8 kg within one year of age and its flesh is highly appreciated. Shrimp farming has been questioned for environmental issues, use of fish oil and fish meal, and spreading diseases. Rearing shrimp in systems without water exchange, know as ZEAH (Zero Exchange Aerobic Heterotrophic Culture systems or bioflocs applies methods that minimize these problems, contributing for the development of sustainable shrimp

  13. ENVIRONMENTAL IMPACT OF FISH FARMING IN FLOATING CAGES IN ISLA ARENA, CAMPECHE

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    Yadira Silva-Cruz

    2011-11-01

    Full Text Available Mariculture is the cultivation of marine species of commercial importance. This activity has intensified in recent decades due to the need for food production. The present study evaluated the impact of Rachycentron canadum (Cobia and Sciaenops ocellatus (Red Drum farming in floating cages along the coasts of Campeche, Mexico. The impact of this mariculture system was evaluated through the physicochemical analysis of the sediment from underneath the cages and the analysis of the quality of the water from the farming area. Results showed high concentrations of nitrogen (> 0.5 % and organic matter (> 80 %, both in the farming area and in the control sites. The concentration of fine sediment showed no spatial or temporal changes. There were no detectable concentrations of nitrites, nitrates, ammonium and phosphates in the water, in a range of 0.1 to 100 mg L-1. The impact caused by this farming system appeared to be non significant, at least in the area of study, due to the constant movement of the water caused by ocean currents which, very likely, carried the waste from the cages to other places.

  14. New records of philometrids (Nematoda: Philometridae) from marine fishes off Australia, including description of four new species and erection of Digitiphilometroides gen. n.

    Science.gov (United States)

    Moravec, Frantisek; Barton, Diane P

    2018-04-16

    The following six species of the Philometridae (Nematoda: Dracunculoidea) were recorded from marine fishes off the northern coast of Australia in 2015 and 2016: Philometra arafurensis sp. n. and Philometra papillicaudata sp. n. from the ovary and the tissue behind the gills, respectively, of the emperor red snapper Lutjanus sebae (Cuvier); Philometra mawsonae sp. n. and Dentiphilometra malabarici sp. n. from the ovary and the tissue behind the gills, respectively, of the Malabar blood snapper Lutjanus malabaricus (Bloch et Schneider); Philometra sp. from the ovary of the goldbanded jobfish Pristipomoides multidens (Day) (Perciformes: all Lutjanidae); and Digitiphilometroides marinus (Moravec et de Buron, 2009) comb. n. from the body cavity of the cobia Rachycentron canadum (Linnaeus) (Perciformes: Rachycentridae). Digitiphilometroides gen. n. is established based on the presence of unique digital cuticular ornamentations on the female body. New gonad-infecting species, P. arafurensis and P. mawsonae, are characterised mainly by the length of spicules (252-264 µm and 351-435 µm, respectively) and the structure of the gubernaculum, whereas P. papillicaudata is characterised mainly by the body length (70 mm) of gravid female, extent of the oesophageal gland, size of caudal projections and the location in the host. Dentiphilometra malabarici differs from congeners mainly in the arrangement of circumoral teeth (in a single row), extent of the oesophageal gland and the absence of sclerotised teeth or protuberances on the oesophageal lobes in the mouth. Digitiphilometroides marinus has not previously been reported from fishes in Australian waters.

  15. Recent advance on aspect of fiheries: A review

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    Ahmad Mohamadi Yalsuyi

    2017-04-01

    Full Text Available In recent years the fishery always has been a growing industry. However, fishery like the other industries had faced with some limitations. Pollution of water resources, fight disease and efforts to increase production efficiency have been important challenges of fishing industry in recent years. Also, world statistics show that the fishing did not have much grown in recent years. On the other hand, aquaculture of marine fish as new industry can be a reliable solution for the management of aquatic ecosystems and restore these reserves, and in recent years, it always has been a significant growth in the production. So far, several species such as Mahimahi (Coryphaena hippurus, European seabass (Dicentrarchus labrax, Cobia (Rachycentron canadum and silver pomfret (Pampus argenteus have been successfully produced and marketed with different aquaculture methods (i.e. cage culture and pen culture. The aim of this study was to summarize marine fish production methods with an emphasis on the production of silver pomfret, as a commercial species and the study of the opportunities and challenges facing this sector in the future.

  16. Rapid review on the use of new age induced breeding agent ‘LHRHa’ in Indian finfish seed production sector

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    Koushik Roy

    2016-08-01

    Full Text Available A focused review on the use of LHRHa in induced breeding of fishes in India was made. Use of LHRHa is mainly restricted to high value brackish water and marine fish species whose market value generally exceeds INR 300-400/kg (USD 4.5-6/kg. Published information on use of LHRHa in induced breeding of fishes in India could document only twelve species out of which nine were brackishwater or marine fish. Besides length and weight, the egg diameter of female fishes (>0.45–0.7 mm is an important criterion for treating the fishes with LHRHa. LHRHa is either used alone or in combination with HCG (most popular, PGE, 17α-MT and Pimozide. Dosage of 20-70 µg/kg body weight for females and 10-40 µg/kg body weight for males with a latency period of 24-36 hours is most common in India. Experiments with LHRHa are being carried out mainly by ICAR-CIBA, Chennai (dominant and ICAR-CMFRI, Kochi. Standardization and optimization of LHRHa dosage has been attained in Asian Seabass (Lates calcarifer, Cobia (Rachycentron canadum, Grey mullet (Mugil cephalus and Spotted scat (Scatophagus argus while in Grouper (Epinephelus tauvina, Moonfish (Monodactylus argenteus, Milk fish (Chanos chanos, Crescent Bass (Terapon jarbua and Silver Pompano (Trachinotus blochii, it is under progress.

  17. The growth of finfish in global open-ocean aquaculture under climate change.

    Science.gov (United States)

    Klinger, Dane H; Levin, Simon A; Watson, James R

    2017-10-11

    Aquaculture production is projected to expand from land-based operations to the open ocean as demand for seafood grows and competition increases for inputs to land-based aquaculture, such as freshwater and suitable land. In contrast to land-based production, open-ocean aquaculture is constrained by oceanographic factors, such as current speeds and seawater temperature, which are dynamic in time and space, and cannot easily be controlled. As such, the potential for offshore aquaculture to increase seafood production is tied to the physical state of the oceans. We employ a novel spatial model to estimate the potential of open-ocean finfish aquaculture globally, given physical, biological and technological constraints. Finfish growth potential for three common aquaculture species representing different thermal guilds-Atlantic salmon ( Salmo salar ), gilthead seabream ( Sparus aurata ) and cobia ( Rachycentron canadum )-is compared across species and regions and with climate change, based on outputs of a high-resolution global climate model. Globally, there are ample areas that are physically suitable for fish growth and potential expansion of the nascent aquaculture industry. The effects of climate change are heterogeneous across species and regions, but areas with existing aquaculture industries are likely to see increases in growth rates. In areas where climate change results in reduced growth rates, adaptation measures, such as selective breeding, can probably offset potential production losses. © 2017 The Author(s).

  18. Amending reduced fish-meal feeds with marine lecithin, but not soy lecithin, improves the growth of juvenile cobia and may attenuate heightened responses to stress challenge.

    Science.gov (United States)

    Trushenski, J; Schwarz, M; Pessoa, W V N; Mulligan, B; Crouse, C; Gause, B; Yamamoto, F; Delbos, B

    2013-02-01

    Sparing of marine resources in aquafeeds can be environmentally and economically advantageous; however, fish meal (FM) replacement can affect the production performance and physiological competence. Phospholipids are increasingly understood to be involved in maintaining growth and vigour in fish and may be deficient in reduced FM formulations. Accordingly, we evaluated the growth and stress tolerance of juvenile cobia fed typical (50% FM) or reduced FM feeds (12% FM) with or without phospholipid amendment [1% marine lecithin (12% FM + Marine PL) or soy lecithin (12% FM + Soy PL)] for 6 weeks in triplicate tanks (N = 3) in a recirculation aquaculture system. The 50% FM feed yielded significantly superior growth and growth efficiency in comparison with the 12% FM and 12% FM+ Soy PL feeds, but the 12% FM+ Marine PL feed yielded comparable results to 50% FM feed. A low-water stress challenge induced elevated plasma glucose, cortisol and lactate levels in all treatments. However, a significant interaction (diet × stress) effect suggested a lesser cortisol response among fish fed the 12% FM+ Marine PL and 50% FM diets. These findings demonstrate that growth performance and, perhaps, resilience of cobia raised on reduced FM feeds may be improved by the addition of marine-origin phospholipid to the diet. © 2011 Blackwell Verlag GmbH.

  19. Conhecimento ecológico local de pescadores da Baía Babitonga, Santa Catarina, Brasil: peixes da família Serranidae e alterações no ambiente marinho = Local ecological knowledge of fishermen from Babitonga Bay, Santa Catarina, Brazil: fishes from the Serranidae family and marine environmental changes

    Directory of Open Access Journals (Sweden)

    Leopoldo Cavaleri Gerhardinger

    2006-07-01

    fishermen and generating conflicts on the law’s applicability. Themain environmental changes registered were: decreasing abundance of fishery resources in general (and in particular that of the “Parambijú” (Cobia Rachycentron canadum, and the effects of the anthropogenic interruption of the “Linguado Channel” on the hydrological and sedimentological characteristics of the Babitonga Bay (channel-bed shallowing and increased water turbidity.

  20. Conhecimento ecológico local de pescadores da Baía Babitonga, Santa Catarina, Brasil: peixes da família Serranidae e alterações no ambiente marinho - DOI: 10.4025/actascibiolsci.v28i3.226 Local ecological knowledge of fishermen from Babitonga Bay, Santa Catarina, Brazil: fishes from the Serranidae family and marine environmental changes - DOI: 10.4025/actascibiolsci.v28i3.226

    Directory of Open Access Journals (Sweden)

    Maurício Hostim Silva

    2007-11-01

    fishermen and generating conflicts on the law’s applicability. The main environmental changes registered were: decreasing abundance of fishery resources in general (and in particular that of the “Parambijú” (Cobia Rachycentron canadum, and the effects of the anthropogenic interruption of the “Linguado Channel” on the hydrological and sedimentological characteristics of the Babitonga Bay (channel-bed shallowing and increased water turbidity.

  1. Ontogenic development of kidney, thymus and spleen and phenotypic expression of CD3 and CD4 receptors on the lymphocytes of cobia (Rachycentroncanadum

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    MARTA C. KLOSTERHOFF

    2015-12-01

    Full Text Available ABSTRACT In the present study was evaluated the ontogenic of immunocompetent organs of cobia up to 53 days after hatching (dah through histology and immunohistochemistry techniques. The kidney was the first lymphohematopoietic organ to appear, at 1 dah, followed by the spleen at 5 dah and the thymus at 7 dah. The first CD3 receptors on the lymphocytes were observed in 27% of the thymic tissue at 7 dah and in 99% at 53 dah. The phenotypic expression of CD3 receptors was registered in 10% of the kidney at 8 dah and in 32% at 53 dah. CD4 receptors were observed in 5% and 63% of the thymic area at 7 and 53 dah, respectively. In the kidney, T4 lymphocytes were first observed at 13 dah in 9% of the organ and in 28% at 53 dah, defining the functional development of the specific system associated with immunological memory capacity.

  2. Ontogenic development of kidney, thymus and spleen and phenotypic expression of CD3 and CD4 receptors on the lymphocytes of cobia (Rachycentroncanadum).

    Science.gov (United States)

    Klosterhoff, Marta C; Pereira Júnior, Joaber; Rodrigues, Ricardo V; Gusmão, Emeline P; Sampaio, Luís A; Tesser, Marcelo B; Romano, Luis A

    2015-01-01

    In the present study was evaluated the ontogenic of immunocompetent organs of cobia up to 53 days after hatching (dah) through histology and immunohistochemistry techniques. The kidney was the first lymphohematopoietic organ to appear, at 1 dah, followed by the spleen at 5 dah and the thymus at 7 dah. The first CD3 receptors on the lymphocytes were observed in 27% of the thymic tissue at 7 dah and in 99% at 53 dah. The phenotypic expression of CD3 receptors was registered in 10% of the kidney at 8 dah and in 32% at 53 dah. CD4 receptors were observed in 5% and 63% of the thymic area at 7 and 53 dah, respectively. In the kidney, T4 lymphocytes were first observed at 13 dah in 9% of the organ and in 28% at 53 dah, defining the functional development of the specific system associated with immunological memory capacity.

  3. Pembentukan Formaldehid Alami pada Beberapa Jenis Ikan Laut selama Penyimpanan dalam Es Curai

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    Jovita Tri Murtini

    2014-11-01

    Full Text Available Penelitian kadar formaldehid alami pada beberapa jenis ikan laut selama penyimpanan dalam es curai telah dilakukan untuk mengetahui intensitas pembentukan formaldehid alami oleh ikan setelah mati. Hasil penelitian ini diharapkan dapat menjadi acuan untuk menduga kemungkinan dilakukannya penyalahgunaan formalin pada ikan. Penelitian dilakukan terhadap ikan laut hidup yang terdiri dari 6 jenis ikan yaitu bawal bintang (Trachinotus blochii, kakap putih (Lates calcarifer, bloch., cobia (Rachycentron canadum, bandeng (Chanos chanos, kerapu cantrang Epinephelus fuscoguttatus-lanceolatus, dan kakap merah/jenaha (Lutjanus johnii. Pengambilan sampel di lapangan dilakukan secara bertahap dan setiap pengambilan terdiri dari dua jenis ikan. Ikan tersebut dibawa ke laboratorium Balai Besar Penelitian dan Pengembangan Pengolahan Produk dan Bioteknologi Kelautan dan Perikanan (BBP4BKP dalam keadaan hidup, kemudian ikan dimatikan dengan cara hipotermal (dimasukkan dalam air es dengan suhu 0–4oC selama 30 menit. Setelah mati ikan dibagi menjadi 3 kelompok dan disimpan dalam peti insulasi yang berisi es dengan perbandingan ikan : es adalah 1 : 3. Pengamatan dilakukan setiap 3 hari selama 18 hari. Parameter yang diamati adalah kadar formaldehid, trimethil amin (TMA, trimethil amin oksida (TMAO dan kadar total volatile base (TVB serta komposisi proksimat pada hari pertama. Hasil penelitian menunjukkan bahwa kandungan formaldehid alami pada hari ke 12 penyimpanan pada bawal bintang, kakap putih, cobia, bandeng, kakap merah, dan kerapu cantrang berturut-turut adalah 0.954; 1.572; 0.964; 0,715; 1.381; dan 1.303 ppm. Pada saat itu kondisi ikan masih segar dengan kandungan TVB di bawah 20 mN% kecuali ikan cobia (28,94 mgN%. Kandungan TMA berkisar 6,09–11,81 mgN% dan TMAO 3,22–11,3 mgN% dan selama penyimpanan cenderung meningkat.

  4. Morphological variation in the cosmopolitan fish parasite Neobenedenia girellae (Capsalidae: Monogenea).

    Science.gov (United States)

    Brazenor, Alexander K; Saunders, Richard J; Miller, Terrence L; Hutson, Kate S

    2018-02-01

    Intra-species morphological variation presents a considerable problem for species identification and can result in taxonomic confusion. This is particularly pertinent for species of Neobenedenia which are harmful agents in captive fish populations and have historically been identified almost entirely based on morphological characters. This study aimed to understand how the morphology of Neobenedenia girellae varies with host fish species and the environment. Standard morphological features of genetically indistinct parasites from various host fish species were measured under controlled temperatures and salinities. An initial field-based investigation found that parasite morphology significantly differed between genetically indistinct parasites infecting various host fish species. The majority of the morphological variation observed (60%) was attributed to features that assist in parasite attachment to the host (i.e. the posterior and anterior attachment organs and their accessory hooks) which are important characters in monogenean taxonomy. We then experimentally examined the effects of the interaction between host fish species and environmental factors (temperature and salinity) on the morphology of isogenic parasites derived from a single, isolated hermaphroditic N. girellae infecting barramundi, Lates calcarifer. Experimental infection of L. calcarifer and cobia, Rachycentron canadum, under controlled laboratory conditions did not confer host-mediated phenotypic plasticity in N. girellae, suggesting that measured morphological differences could be adaptive and only occur over multiple parasite generations. Subsequent experimental infection of a single host species, L. calcarifer, at various temperatures (22, 30 and 32 °C) and salinities (35 and 40‰) showed that in the cooler environments (22 °C) N. girellae body proportions were significantly smaller compared with warmer temperatures (30 and 32 °C; P < 0.0001), whereas salinity had no effect. This

  5. Comparative effect of pesticides on brain acetylcholinesterase in tropical fish.

    Science.gov (United States)

    Assis, Caio Rodrigo Dias; Linhares, Amanda Guedes; Oliveira, Vagne Melo; França, Renata Cristina Penha; Carvalho, Elba Veronica Matoso Maciel; Bezerra, Ranilson Souza; de Carvalho, Luiz Bezerra

    2012-12-15

    Monitoring of pesticides based on acetylcholinesterase (AChE; EC 3.1.1.7) inhibition in vitro avoids interference of detoxification defenses and bioactivation of some of those compounds in non-target tissues. Moreover, environmental temperature, age and stress are able to affect specific enzyme activities when performing in vivo studies. Few comparative studies have investigated the inter-specific differences in AChE activity in fish. Screening studies allow choosing the suitable species as source of AChE to detect pesticides in a given situation. Brain AChE from the tropical fish: pirarucu (Arapaima gigas), cobia (Rachycentron canadum) and Nile tilapia (Oreochromis niloticus) were characterized and their activities were assayed in the presence of pesticides (the organophosphates: dichlorvos, diazinon, chlorpyrifos, temephos, tetraethyl pyrophosphate- TEPP and the carbamates: carbaryl and carbofuran). Inhibition parameters (IC₅₀ and Ki) for each species were found and compared with commercial AChE from electric eel (Electrophorus electricus). Optimal pH and temperature were found to be 8.0 and 35-45 °C, respectively. A. gigas AChE retained 81% of the activity after incubation at 50 °C for 30 min. The electric eel enzyme was more sensitive to the compounds (mainly carbofuran, IC₅₀ of 5 nM), excepting the one from A. gigas (IC₅₀ of 9 nM) under TEPP inhibition. These results show comparable sensitivity between purified and non-purified enzymes suggesting them as biomarkers for organophosphorus and carbamate detection in routine environmental and food monitoring programs for pesticides. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Effects of graded taurine levels on juvenile cobia

    Science.gov (United States)

    Taurine, which has multiple important physiological roles in teleost fish and mammals, is an amino acid not found in alternative protein sources not derived from animals. Although taurine is found in fish-meal-based feeds, its high water solubility leads to lower taurine levels in reduction-process-...

  7. Hiperplasia em túnicas de artérias coronárias de beijupirás criados em sistema offshore

    Directory of Open Access Journals (Sweden)

    V.F. Pedrosa

    2015-06-01

    Full Text Available As lesões coronarianas já foram relatadas em espécies de peixes anádromos, com características semelhantes às observadas em aterosclerose humana, mas não em peixes cultivados sem interferência de padrões reprodutivos. Objetivou-se descrever lesões coronarianas em beijupirá (Rachycentron canadum criado em sistema offshore, em 54 exemplares coletados ao longo do cultivo de oito meses. Amostras de tecido cardíaco de alevinos e juvenis foram submetidas à análise histopatológica e à microscopia eletrônica de transmissão (MET, para visualização de lesões coronarianas, sendo as lâminas histológicas coradas pela técnica de hematoxilina-eosina, ácido periódico de Schiff, alcian blue e reticulina de Gomori. Exames realizados pela fotomicroscopia de luz evidenciaram lesões arteriais caracterizadas por hiperplasia das túnicas íntima e média de artérias coronárias em, respectivamente, 29,63% e 79,63% dos animais, com redução do lúmen arterial. Na MET, foram observadas alterações na estrutura das coronárias com espessamento do endotélio e membrana basal, proliferação de fibroblastos e fibras colágenas, com acúmulo de material lipídico subendotelial, resíduos celulares aderidos à membrana basal e vesículas pinocitóticas com presença de lisossomos isolados. Constatou-se que os peixes da espécie Rachycentron canadum criados em cativeiro desenvolvem lesão arterial do tipo crônica degenerativa inflamatória.

  8. 77 FR 19229 - Fisheries of the South Atlantic; South Atlantic Fishery Management Council; Public Meetings

    Science.gov (United States)

    2012-03-30

    ... cobia; and the recent stock assessment of Spanish mackerel and cobia. The AP will discuss developing amendments, including Mackerel Amendment 19 addressing permits and sale of bag- limit mackerel and cobia, and...

  9. Trials advance low-salinity culture of Cobia, Pompano, and other species

    Science.gov (United States)

    An ongoing collaborative research effort between scientists of the USDA Agricultural Research Service and aquaculture researchers of the Harbor Branch Oceanographic Institute at Florida Atlantic University to develop technologies for rearing fish in low salinity recirculating aquaculture systems is ...

  10. Trials advance low-salinity culture of cobia, pompano, other species

    Science.gov (United States)

    A collaborative effort between the Agricultural Research Service of USDA and Harbor Branch Oceanographic Institute of Florida Atlantic University, which was established to develop technologies for rearing marine fish in low-cost, energy efficient low-salinity recirculating aquaculture systems (RAS) ...

  11. Characterization of catalytic efficiency parameters of brain cholinesterases in tropical fish.

    Science.gov (United States)

    de Assis, Caio Rodrigo Dias; Linhares, Amanda Guedes; Oliveira, Vagne Melo; França, Renata Cristina Penha; Santos, Juliana Ferreira; Marcuschi, Marina; Carvalho, Elba Verônica Matoso Maciel; Bezerra, Ranilson Souza; Carvalho, Luiz Bezerra

    2014-12-01

    Brain cholinesterases from four fish (Arapaima gigas, Colossoma macropomum, Rachycentron canadum and Oreochromis niloticus) were characterized using specific substrates and selective inhibitors. Parameters of catalytic efficiency such as activation energy (AE), k(cat) and k(cat)/k(m) as well as rate enhancements produced by these enzymes were estimated by a method using crude extracts described here. Despite the BChE-like activity, specific substrate kinetic analysis pointed to the existence of only acetylcholinesterase (AChE) in brain of the species studied. Selective inhibition suggests that C. macropomum brain AChE presents atypical activity regarding its behavior in the presence of selective inhibitors. AE data showed that the enzymes increased the rate of reactions up to 10(12) in relation to the uncatalyzed reactions. Zymograms showed the presence of AChE isoforms with molecular weights ranging from 202 to 299 kDa. Values of k(cat) and k(cat)/k(m) were similar to those found in the literature.

  12. Preparation and characterisation of Punica granatum pericarp aqueous extract loaded chitosan-collagen-starch membrane: role in wound healing process.

    Science.gov (United States)

    Amal, B; Veena, B; Jayachandran, V P; Shilpa, Joy

    2015-05-01

    Engineered scaffolds made from natural biomaterials are crucial elements in tissue engineering strategies. In this study, biological scaffold like chitosan-collagen-starch membrane (CCSM) loaded with the antibacterial agent, Punica granatum pericarp aqueous extract was explored for enhanced regeneration of epithelial tissue during wound healing. Collagen was extracted from Rachycentron canadum fish skin. Membranous scaffold was prepared by mixing collagen, starch and chitosan in a fixed proportion, loaded with aqueous extract of P. granatum and its anti-pseudomonal activity was studied. Morphological characterization by SEM and mechanical property like tensile strength of the membrane were studied. Excision wound of 2 cm(2) size was induced in Guinea pig and the effect of P. granatum extract loaded CCSM in wound healing was studied. The SEM image showed deep pores in the membrane and also possessed good tensile strength. Wound surface area was reduced prominently in the experimental group with P. granatum extract loaded CCSM when compared to the group with unloaded membrane and the one with no membrane. Punica granatum extract loaded CCSM has antipseudomonal property and supported enhanced epithelial cell proliferation without leaving a scar after wound healing. This has significant therapeutic application in membranous scaffold mediated skin repair and regeneration.

  13. 78 FR 68416 - South Atlantic Fishery Management Council (SAFMC); Public Meeting

    Science.gov (United States)

    2013-11-14

    ..., Spanish mackerel and cobia; 2. Receive an update on the status of amendments under formal Secretarial..., fishing seasons, transit provisions, framework procedure, cobia ACLs), develop recommendations for...

  14. 77 FR 13096 - Gulf of Mexico Fishery Management Council; Public Meeting

    Science.gov (United States)

    2012-03-05

    ... and Spanish mackerel, as well as cobia. It also considers potential changes to regulations regarding maintaining and renewing commercial fishing permits and adding a commercial permit requirement to sell cobia...

  15. 76 FR 41766 - Gulf of Mexico Fishery Management Council; Public Meeting

    Science.gov (United States)

    2011-07-15

    ... group Spanish mackerel, and Gulf group cobia. It also contains measures to remove cero, little tunny... separate cobia into Atlantic and Gulf migratory groups. Similar measures are being proposed for the...

  16. 77 FR 43049 - Fisheries of the Gulf of Mexico and South Atlantic; Southeast Data, Assessment and Review (SEDAR...

    Science.gov (United States)

    2012-07-23

    ... Spanish mackerel and cobia fisheries will consist of a series of workshops and supplemental webinars. This... cobia fisheries. Special Accommodations This meeting is accessible to people with disabilities. Requests...

  17. 76 FR 16730 - South Atlantic Fishery Management Council; Public Meetings

    Science.gov (United States)

    2011-03-25

    ... migratory groups of king mackerel, Spanish mackerel and cobia. The amendment addresses establishment of... separate migratory groups of cobia (between the Gulf and South Atlantic), sector allocations, and possible...

  18. 78 FR 30866 - South Atlantic Fishery Management Council; Public Meeting

    Science.gov (United States)

    2013-05-23

    ... catches versus ACLs for Atlantic group King Mackerel, Spanish Mackerel and Cobia. 2. Receive and discuss an SSC report on SEDAR 28, pertaining to Spanish Mackerel and Cobia, and take action as necessary. 3...

  19. 76 FR 20957 - Gulf of Mexico Fishery Management Council; Public Meeting

    Science.gov (United States)

    2011-04-14

    ... exceeded for Gulf group king mackerel, Gulf group Spanish mackerel, and Gulf group cobia. It also contains... framework procedure, and separate cobia into Atlantic and Gulf migratory groups. Similar measures are being...

  20. 77 FR 51771 - Fisheries of the Gulf of Mexico and South Atlantic; Southeast Data, Assessment, and Review (SEDAR...

    Science.gov (United States)

    2012-08-27

    ... Process Webinar for Gulf of Mexico and South Atlantic Spanish Mackerel and Cobia AGENCY: National Marine... of SEDAR 28 Gulf of Mexico and South Atlantic Spanish mackerel and cobia assessment webinar. SUMMARY: The SEDAR 28 assessment of the Gulf of Mexico and South Atlantic Spanish mackerel and cobia fisheries...

  1. 78 FR 15708 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR); Public Meeting

    Science.gov (United States)

    2013-03-12

    ...: Notice of SEDAR 28 Gulf of Mexico Spanish mackerel and cobia Review Workshop. SUMMARY: The SEDAR 28 assessment of the Gulf of Mexico Spanish mackerel and cobia fisheries will consist of a series of workshops... and cobia. Although non-emergency issues not contained in this agenda may come before this group for...

  2. 77 FR 60967 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment and Review (SEDAR); Public Meeting

    Science.gov (United States)

    2012-10-05

    ...: Notice of SEDAR 28 Gulf of Mexico Spanish mackerel and cobia assessment webinars. SUMMARY: The SEDAR 28 assessment of the Gulf of Mexico Spanish mackerel and cobia fisheries will consist of a series of workshops... modeling methodologies for the Gulf of Mexico Spanish mackerel and cobia fisheries. Special Accommodations...

  3. 77 FR 66818 - Fisheries of the Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR); Assessment...

    Science.gov (United States)

    2012-11-07

    ... Gulf of Mexico Spanish Mackerel and Cobia AGENCY: National Marine Fisheries Service (NMFS), National... mackerel and cobia assessment webinar. SUMMARY: The SEDAR 28 assessment of the Gulf of Mexico Spanish mackerel and cobia fisheries will consist of a series of workshops and supplemental webinars. This notice...

  4. An Investigation of Wave Impact Duration in High-Speed Planing Craft in Rough Water

    Science.gov (United States)

    2014-04-01

    10 Figure 9. CCD’s CObIA cRIO Data Acquisition System.............................................................11 Figure 10...environment. CCD’s CObIA system shown in Figure 9, based on National Instruments Compact RIO, has proven itself suitable for seakeeping measurements in...even the most extreme conditions. Figure 9. CCD’s CObIA cRIO Data Acquisition System Personal computers have also improved, allowing engineers to

  5. 78 FR 14983 - Fisheries of the Gulf of Mexico; Gulf of Mexico Fishery Management Council; Public Meeting

    Science.gov (United States)

    2013-03-08

    ... the Gulf of Mexico; Gulf of Mexico Fishery Management Council; Public Meeting AGENCY: National Marine... of Gulf of Mexico Fishery Management Council Spanish Mackerel and Cobia Stock Assessment Review Workshop. SUMMARY: Independent peer review of Gulf of Mexico Spanish Mackerel and Cobia stocks will be...

  6. New Mediterranean Biodiversity Records (October 2015

    Directory of Open Access Journals (Sweden)

    F. CROCETTA

    2015-11-01

    concomitantly from the entire Aegean Sea. Turkey: the alien rhodophyte Antithamnion hubbsii is first recorded from Turkey and the entire eastern Mediterranean. New distributional data are also offered for the native fishes Alectis alexandrina and Heptranchias perlo. In particular, the former record is constituted by a juvenile of 21.38 mm total length, whilst the latter by a mature male. Cyprus: the rare native cephalopod Macrotritopus defilippi, and the alien crab Atergatis roseus, sea slug Plocamopherus ocellatus and fish Cheilodipterus novemstriatus are first recorded from the entire country. Lebanon: the alien crabs Actaea savignii and Matuta victor, as well as the alien fish Synanceia verrucosa, are first recorded from the entire country. In addition, the first Mediterranean record of A. savignii is backdated to 2006, whilst the high number of M. victor specimens observed in Lebanon first suggest its establishment in the basin. The Atlantic fishes Paranthias furcifer and Seriola fasciata, and the circumtropical Rachycentron canadum, are also first reported from the country. P. furcifer record backdate its presence in the Mediterranean to 2007, whilst S. fasciata records backdate its presence in the eastern Mediterranean to 2005. Finally, two of these latter species have been recently ascribed to alien species, but all the three species may better fit the cryptogenic category, if not a new one.

  7. 75 FR 27649 - 2010 Annual Determination for Sea Turtle Observer Requirements

    Science.gov (United States)

    2010-05-18

    ... the addresses listed below: NMFS, Northeast Region, 55 Great Republic Drive, Gloucester, MA 01930-2298... mackerel, whiting, bluefish, pompano, spot, croaker, little tunny, bonita, jack crevalle, cobia, and...

  8. 76 FR 60444 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

    Science.gov (United States)

    2011-09-29

    ..., cobia, cero, little tunny, dolphin, and bluefish (Gulf only). At present, only king mackerel, Spanish... bluefish from the Coastal Migratory Pelagic FMP. The Councils and NMFS have determined these species are...

  9. 76 FR 82057 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

    Science.gov (United States)

    2011-12-29

    ... mackerel, and cobia. The intent of this rule is to specify ACLs for species not undergoing overfishing... management and may put those populations unknowingly at risk of overfishing. It is not clear how removing... analysis accomplishes any of the following: prevents overfishing and protects, restores and promotes the...

  10. 76 FR 65662 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

    Science.gov (United States)

    2011-10-24

    ... mackerel, and cobia. The intent of this rule is to specify ACLs for species not undergoing overfishing... overfishing, ACLs and AMs must be established at a level that prevents overfishing and helps to achieve OY... mechanism for specifying ACLs at a level such that overfishing does not occur in a fishery and AMs to...

  11. 76 FR 81479 - Fisheries of the South Atlantic and Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR...

    Science.gov (United States)

    2011-12-28

    ... stock, estimates biological benchmarks, projects future population conditions, and recommends research... mackerel and cobia. SUMMARY: The SEDAR assessments of the South Atlantic and Gulf of Mexico stocks of... Review (SEDAR) process, a multi-step method for determining the status of fish stocks in the Southeast...

  12. Comparative profiling of microbial community of three economically important fishes reared in sea cages under tropical offshore environment.

    Science.gov (United States)

    Rasheeda, M K; Rangamaran, Vijaya Raghavan; Srinivasan, Senthilkumar; Ramaiah, Sendhil Kumar; Gunasekaran, Rajaprabhu; Jaypal, Santhanakumar; Gopal, Dharani; Ramalingam, Kirubagaran

    2017-08-01

    The present study was undertaken to evaluate the microbial composition of farmed cobia pompano and milkfish, reared in sea-cages by culture-independent methods. This study would serve as a basis for assessing the general health of fish, identifying the dominant bacterial species present in the gut for future probiotic work and in early detection of potential pathogens. High-throughput sequencing of V3-V4 hyper variable regions of 16S rDNA on Illumina MiSeq platform facilitated unravelling of composite bacterial population. Analysis of 1.3 million quality-filtered sequences revealed high microbial diversity. Characteristic marine fish gut microbes: Vibrio and Photobacterium spp. showed prevalence in cobia and pompano whereas Pelomonas and Fusobacterium spp. dominated the gut of milkfish. Pompano hindgut with 10,537 operational taxonomy units (OTUs) exhibited the highest alpha-diversity index followed by cobia (10,435) and milkfish (2799). Additionally unique and shared OTUs in each gut type were identified. Gammaproteobacteria dominated in cobia and pompano while Betaproteobacteria showed prevalence in milkfish. We obtained 96 shared OTUs among the three species though the numbers of reads were highly variable. These differences in microbiota of farmed fish reared in same environment were presumably due to differences in the gut morphology, physiological behavior and host specificity. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Making History: SACES Presidential Leadership 1949-1998.

    Science.gov (United States)

    Sheeley, Vernon Lee

    This booklet provides educational, professional, and biographical information on 48 presidents of the Southern Association for Counselor Education and Supervision. A photo of each president is included. All leaders from 1949-1998 are covered. The presidents are: Donna Henderson, Debra Cobia, Pamela Paisley, Larry C. Loesch, Charlotte M. Taylor,…

  14. Fortescue field, Gippsland basin: Flank potential realized

    Energy Technology Data Exchange (ETDEWEB)

    Hendrich, J.H.; Schwebel, D.A.; Palmer, I.D. (Esso Asustralia Ltd., Sydney, New South Wales (Australia))

    1990-09-01

    Fortescue field was the last major oil field to be discovered in the offshore Gippsland basin, southeastern Australia. The discovery well, 1 West Halibut, was drilled in 1978 on the basis of a 1-km seismic grid as a follow up to the dry 1 Fortescue wildcat. Data from this well were interpreted to indicate that there was a high probability of a stratigraphic trap occurring on the western flank of the giant Halibut-Cobia structure. The 2, 3, and 4 Fortescue wells were drilled by early 1979 to determine the limits of the field, delineate the stratigraphy, and define the hydrocarbon contacts. Cobia A had the dual purpose of developing the Cobia field and the southern extent of the Fortescue reservoirs that were inaccessible to the Fortescue A plat-form. At the conclusion of development drilling in early 1986, eight Cobia A wells and 20 Fortescue A wells were capable of producing from Fortescue reservoirs. The Fortescue reservoirs are Eocene sandstones that were deposited in coastal plain, upper shoreface, and lower shoreface environments. Integration of well log correlations, stratigraphic interpretations, reservoir pressure data, and seismic data indicates that these Fortescue reservoirs are stratigraphically younger than, and are hydraulically separated from, the underlying Halibut-Cobia fields. Pressure data acquired during development drilling and while monitoring subsequent production performance have conclusively demonstrated that there are at least three separate hydraulic systems active within the Fortescue field. Fortescue field dimensions are approximately 11 km x 4 km with a maximum relief of 100 m above the original oil-water contact. Reserves are estimated at 280,000 STB, based on original oil in place estimates of 415,000 STB and recovery factors in the 65-70% range. Production rate peaked in 1984 at 100 K BOPD from the combined development facilities and was sustained until late 1986. More than two-thirds of the reserves have been produced to date.

  15. Factors affecting the abundance of selected fishes near oil and gas platforms in the northern Gulf of Mexico

    International Nuclear Information System (INIS)

    Stanley, D.R.; Wilson, C.A.

    1991-01-01

    A logbook program was initiated to determine the relative abundance of selected fish species around oil and gas platforms off the Louisiana coast. Logbooks were maintained by 55 anglers and 10 charterboat operators from March 1987 to March 1988. A total of 36,839 fish were caught representing over 46 different species. Principal component analysis (PCA) grouped the seventeen most abundant species into reef fish, pelagic fish, bluefish-red drum, Atlantic croaker-silver/sand seatrout, and cobia-shark-blue runner associations. Multiple regression analyses were used to compare PCA groupings to physical platform, temporal, geological, and angler characteristic variables and their interactions. Reef fish, Atlantic croaker, and silver/sand seatrout abundances were highest near large, structurally complex platforms in relatively deep water. High spotted seatrout abundances were correlated with small, unmanned oil and gas platforms in shallow water. Pelagic fish, bluefish, red drum, cobia, and shark abundances were not related to the physical parameters of the platforms

  16. Factors affecting the abundance of selected fishes near oil and gas platforms in the northern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Stanley, D.R.; Wilson, C.A. (Louisiana State Univ., Baton Rouge (United States))

    1991-01-01

    A logbook program was initiated to determine the relative abundance of selected fish species around oil and gas platforms off the Louisiana coast. Logbooks were maintained by 55 anglers and 10 charterboat operators from March 1987 to March 1988. A total of 36,839 fish were caught representing over 46 different species. Principal component analysis (PCA) grouped the seventeen most abundant species into reef fish, pelagic fish, bluefish-red drum, Atlantic croaker-silver/sand seatrout, and cobia-shark-blue runner associations. Multiple regression analyses were used to compare PCA groupings to physical platform, temporal, geological, and angler characteristic variables and their interactions. Reef fish, Atlantic croaker, and silver/sand seatrout abundances were highest near large, structurally complex platforms in relatively deep water. High spotted seatrout abundances were correlated with small, unmanned oil and gas platforms in shallow water. Pelagic fish, bluefish, red drum, cobia, and shark abundances were not related to the physical parameters of the platforms.

  17. Anti-leech activity of Scutellaria baicalensis and Morinda citrifolia extracts against Piscicola geometra

    Science.gov (United States)

    Rizky, P. N.; Cheng, T. C.; Nursyam, H.

    2018-04-01

    Piscicola geometra leeches are naturally infecting cobia juvenile. The leeches attach to cobia by sucking and biting its surface and provide the gate of second infection. Water extracts of Scutellaria baicalensis root and Morinda citrifolia leaves were used to be tested through In Vitro method to look for the anti-leeches activity against Piscicola geometra. In this study, a total number of 800 leeches from infected cobia were prepared. The anti-leech activity from water extract of S. baicalensis root and M. citrifolia leaves were compared in different dilutions of plant extracts for 96 hours. Significant anti-leech activity was observed with M. citrifolia leaves with 80% mortality of leeches. S. baicalensis root showed higher anti-leech activity with 100% mortality of leeches. The average time was needed for S.baicalensis root to paralyzing and kill the leeches were 8h, 40h, 48h, 72h, and 96h in various dilutions of S. baicalensis root. This study indicated that S. baicalensis water extract had a potent for new anti-leeches agent.

  18. Extensión del límite austral de distribución de tres especies de peces óseos tropicales en la costa de la Provincia de Buenos Aires, Argentina

    OpenAIRE

    Milessi, Andres Conrado; Colonello, Jorge H.; Cortés, Federico; Lasta, Carlos Ángel; Waessle, Juan A.; Allega, Lucrecia

    2012-01-01

    Se presentan tres nuevos registros de especies de peces óseos cuya distribución corresponde a aguas tropicales, capturados por buques pesqueros en la costa de la Provincia de Buenos Aires, Argentina (CPBA, 36º-38ºS). Los ejemplares corresponden a las especies: Rachycentrum canadum, Elops saurus y Caulolatilus chrysops. Estos registros amplían significativamente el límite austral de su distribución. La presencia ocasional de estas especies está asociada al transporte de agua subtropical cálida...

  19. Extensión del límite austral de distribución de tres especies de peces óseos tropicales en la costa de la Provincia de Buenos Aires, Argentina Southern extension of three species of tropical bony fishes along the coast of Buenos Aires Province, Argentina

    OpenAIRE

    Andrés C Milessi; Jorge H Colonello; Federico Cortés; Carlos A Lasta; Juan A Waessle; Lucrecia Allega

    2012-01-01

    Se presentan tres nuevos registros de especies de peces óseos cuya distribución corresponde a aguas tropicales, capturados por buques pesqueros en la costa de la Provincia de Buenos Aires, Argentina (CPBA, 36°-38°S). Los ejemplares corresponden a las especies: Rachycentrum canadum, Elops saurus y Caulolatilus chrysops. Estos registros amplían significativamente el límite austral de su distribución. La presencia ocasional de estas especies está asociada al transporte de agua subtropical cálida...

  20. Extensión del límite austral de distribución de tres especies de peces óseos tropicales en la costa de la Provincia de Buenos Aires, Argentina Southern extension of three species of tropical bony fishes along the coast of Buenos Aires Province, Argentina

    Directory of Open Access Journals (Sweden)

    Andrés C Milessi

    2012-11-01

    Full Text Available Se presentan tres nuevos registros de especies de peces óseos cuya distribución corresponde a aguas tropicales, capturados por buques pesqueros en la costa de la Provincia de Buenos Aires, Argentina (CPBA, 36°-38°S. Los ejemplares corresponden a las especies: Rachycentrum canadum, Elops saurus y Caulolatilus chrysops. Estos registros amplían significativamente el límite austral de su distribución. La presencia ocasional de estas especies está asociada al transporte de agua subtropical cálida proveniente de la plataforma continental brasilera. Esta hipótesis es probada mediante el análisis de imágenes satelitales de temperatura superficial del mar.We document the southern records of three species of tropical bony fishes along the coast of Buenos Aires Province, Argentina (CBAP, 36-38°S. Rachycentrum canadum, Elops saurus and Caulolatilus chrysops were caught by bottom-trawl commercial vessels. Records presented here significantly extend southward their latitudinal distribution from those previously reported. Using sea surface temperature satellite images we show a southward warm circulation event from Brazil as a putative factor to explain the occurrence of these bony fishes in the CBAP.

  1. Four new bass strait platforms -a project manager's view

    Energy Technology Data Exchange (ETDEWEB)

    Power, J.W.

    1982-05-01

    The offshore development by Esso/BHP of the West Kingfish, Cobia, Fortescue and Flounder oil fields in the Gippsland Basin is one of the significant undertakings by the petroleum industry during the 1980s. Production from the fields will help sustain the current level of production from Bass Strait into the latter part of this decade. This paper examines some of the principal project management issues and actions involved in the planning and execution of the design and construction phases of the platforms and pipelines associated with each of these fields.

  2. Effect of three diets in the experimental culture of the common snook (Centropomus undecimalis Bloch, 1792

    Directory of Open Access Journals (Sweden)

    Carmen Polonía R

    2017-09-01

    Full Text Available Objective. To evaluate the effect of three diets on the growth of juvenile common snook (Centropomus undecimalis maintained in freshwater ponds Materials and methods. 108 juvenile of common snook were homogenous and randomly distributed in a pond, divided into 9 corrals of 50 m2. Three diets were applied (D1: commercial food for trout, 45% protein; D2: commercial food for cobia, 50% protein and D3: fresh fish, 17.52% protein. The experimental treatments were assigned in triplicate and diets were supplied in two daily doses. Biometrics were performed every 20 days to assess: weight, size, Length-Weight correlation, Feed Conversion Factor (FCA, Condition Factor (K, Specific Growth Rate (SGR and survival; during 120 days. The results were evaluated with a one-way ANOVA, when differences (p<0.05 were found the means were compared by test Median Mood, otherwise a pos-hoc test was performed (Tukey HSD. Results. Applying the test of Mood Median significant differences were found, showing the highest growth with D2, where values of SGR=0.65±0.09 g/day; FCA=3.76 and K=0.81±0.06. Survival was D1=51.4%, D2=50% and D3=77.8% without inferring statistically among the different diets. Conclusions. The culture of this species in freshwater ponds with commercial food for cobia, is viable in terms of growth and weight gain.

  3. Offshore oil production not significant polluter, says government report

    Energy Technology Data Exchange (ETDEWEB)

    Danenberger, E.P.

    1977-11-01

    Only 0.0028% of the oil produced in the Gulf of Mexico from 1971 through 1975 was spilled. World-wide, natural seeps introduce nearly 7 times more oil into the sea than offshore activity, while transportation, the worst offender, puts in 25 times more than offshore oil. The report includes data for spills of 50 bbl or less; about 85.5% of the total spill volume was from 5 of the 5857 incidents. In only one case was environmental damage reported, when minor amounts of oil reached 1000 ft of beach on the Chandeleur Islands after the 9/9/74 Cobia pipeline break. The report states that 50 ppm discharges cause no adverse effect, and that hydrocarbons in this concentration may even benefit microbial sea life.

  4. Multi-gene phylogeny of jacks and pompanos (Carangidae), including placement of monotypic vadigo Campogramma glaycos.

    Science.gov (United States)

    Damerau, M; Freese, M; Hanel, R

    2018-01-01

    In this study, the phylogenetic trees of jacks and pompanos (Carangidae), an ecologically and morphologically diverse, globally distributed fish family, are inferred from a complete, concatenated data set of two mitochondrial (cytochrome c oxidase I, cytochrome b) loci and one nuclear (myosin heavy chain 6) locus. Maximum likelihood and Bayesian inferences are largely congruent and show a clear separation of Carangidae into the four subfamilies: Scomberoidinae, Trachinotinae, Naucratinae and Caranginae. The inclusion of the carangid sister lineages Coryphaenidae (dolphinfishes) and Rachycentridae (cobia), however, render Carangidae paraphyletic. The phylogenetic trees also show with high statistical support that the monotypic vadigo Campogramma glaycos is the sister to all other species within the Naucratinae. © 2017 The Fisheries Society of the British Isles.

  5. Fortescue reservoir development and reservoir studies

    Energy Technology Data Exchange (ETDEWEB)

    Henzell, S.T.; Hicks, G.J.; Horden, M.J.; Irrgang, H.R.; Janssen, E.J.; Kable, C.W.; Mitchell, R.A.H.; Morrell, N.W.; Palmer, I.D.; Seage, N.W.

    1985-03-01

    The Fortescue field in the Gippsland Basin, offshore southeastern Australia is being developed from two platforms (Fortescue A and Cobia A) by Esso Australia Ltd. (operator) and BHP Petroleum. The Fortescue reservoir is a stratigraphic trap at the top of the Latrobe Group of sediments. It overlies the western flank of the Halibut and Cobia fields and is separated from them by a non-net sequence of shales and coals which form a hydraulic barrier between the two systems. Development drilling into the Fortescue reservoir commenced in April 1983 with production coming onstream in May 1983. Fortescue, with booked reserves of 44 stock tank gigalitres (280 million stock tank barrels) of 43/sup 0/ API oil, is the seventh major oil reservoir to be developed in the offshore Gippsland Basin by Esso/BHP. In mid-1984, after drilling a total of 20 exploration and development wells, and after approximately one year of production, a detailed three-dimensional, two-phase reservoir simulation study was performed to examine the recovery efficiency, drainage patterns, pressure performance and production rate potential of the reservoir. The model was validated by history matching an extensive suite of Repeat Formation Test (RFT) pressure data. The results confirmed the reserves basis, and demonstrated that the ultimate oil recovery from the reservoir is not sensitive to production rate. This result is consistent with studies on other high quality Latrobe Group reservoirs in the Gippsland Basin which contain undersaturated crudes and receive very strong water drive from the Basin-wide aquifer system. With the development of the simulation model during the development phase, it has been possible to more accurately define the optimal well pattern for the remainder of the development.