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Bronwyn M. Gillanders - One of the best experts on this subject based on the ideXlab platform.
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comparison of deterministic growth models fitted to length at age data of the piked spurdog squalus Megalops in south eastern australia
Marine and Freshwater Research, 2007Co-Authors: Matias J Braccini, Bronwyn M. Gillanders, Terence I Walker, Javier TovaravilaAbstract:Age and growth estimates of Squalus Megalops were derived from the first dorsal fin spine of 452 sharks, ranging from 274 to 622 mm total length. Age bias plots and indices of precision indicated that the ageing method was precise and unbiased. Edge analysis of the enameled surface of whole spines and similarities in the banding pattern deposited in the enameled surface of spines and in spine sections supported the hypothesis of annual band formation. Multiple versions of two growth models were fitted to length-at-age data, from which a two-phase von Bertalanffy model produced the best fit. For males, the change in growth rate corresponded with size-at-maturity, whereas for females, the change was slightly before size-at-maturity. Regardless of the growth model used, growth rate of females (0.034 to 0.098 years −1 ) was very low, making S. Megalops highly susceptible to overexploitation by fisheries.
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Notas sobre la estructura poblacional del tiburón Squalus Megalops en el sureste de Australia
Ciencias Marinas, 2006Co-Authors: J. M. Braccini, Bronwyn M. Gillanders, T. I. WalkerAbstract:Opportunistic sampling suggested a complex population structure for Squalus Megalops in southeastern Australia. A total of 929 sharks were analyzed. The sex...
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hierarchical approach to the assessment of fishing effects on non target chondrichthyans case study of squalus Megalops in southeastern australia
Canadian Journal of Fisheries and Aquatic Sciences, 2006Co-Authors: Matias J Braccini, Bronwyn M. Gillanders, Terence I WalkerAbstract:A three-levelled hierarchical risk assessment approach was trialed using piked spurdog (Squalus Megalops )t o evaluate the suitability of the approach for chondrichthyan species. At level 1, a qualitative assessment indicated that the only fishing-related activity to have moderate or high impact on S. Megalops was "capture fishing" by otter trawl, Danish seine, gillnet, and automatic longline methods. At level 2, a semi-quantitative assessment ranked S. Megalops at risk because of its low biological productivity and, possibly, its catch susceptibility from cumulative effects across the separate fishing methods. Finally, at level 3, a quantitative assessment showed that population growth is slow even under the assumption of density-dependent compensation where the fishing mortality rate equals the natural mortality rate. Although published information indicates that relative abundance has been stable in several regions of southern Australia, it is concluded that given its low biological productivity, changed fishing practices leading to increased fishing mortality could quickly put S. Megalops at high risk. The hierarchical approach appears particularly useful for assessment of chondrichthyan species in data-limited fisheries. This approach allows for a management response at any level, optimizing research and management efforts by identifying and excluding low-risk species from data intensive assessments. Resume : Nous employons une methode hierarchique a trois niveaux pour l'evaluation des risques chez le requin ai-
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total and partial length length mass mass and mass length relationships for the piked spurdog squalus Megalops in south eastern australia
Fisheries Research, 2006Co-Authors: Matias J Braccini, Bronwyn M. Gillanders, Terence I WalkerAbstract:Abstract Common commercial fishing practices of eviscerating, beheading and finning sharks create the need for using conversion factors from partial lengths to total length and from partial masses to total mass. In the present paper, these conversion factors were calculated for Squalus Megalops . In addition, total and partial length–length and mass–length relationships of male and female S. Megalops were compared using different ranges of size. There was no effect of size range on measurements reflecting only somatic growth (fork and carcass lengths; carcass, pectoral fin and caudal fin masses) but for variables reflecting somatic and reproductive growth (total and liver masses), different outcomes can be expected when different ranges of size are compared.
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notas sobre la estructura poblacional del tiburon squalus Megalops en el sureste de australia notes on the population structure of the piked spurdog squalus Megalops in southeastern australia
2006Co-Authors: J. M. Braccini, Bronwyn M. GillandersAbstract:Opportunistic sampling suggested a complex population structure for Squalus Megalops in southeastern Australia. A total of 929 sharks were analyzed. The sex ratio was biased towards females and there was sexual size dimorphism, with females attaining a larger maximum size than males. Individual analysis of selected fishing shots suggested that S. Megalops had a complex population structure, and was segregated by sex, size and breeding condition. Small females and males segregated from large females. In addition, large females in the first year of pregnancy seemed to be separated from those in the second year of pregnancy.
Aijiang Guo - One of the best experts on this subject based on the ideXlab platform.
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Characterization of the complete mitochondrial genome of the cloacal tapeworm Cloacotaenia Megalops (Cestoda: Hymenolepididae).
Parasites & vectors, 2016Co-Authors: Aijiang GuoAbstract:The cloacal tapeworm Cloacotaenia Megalops (Hymenolepididae) is one of the most common cestode parasites of domestic and wild ducks worldwide. However, limited information is available regarding its epidemiology, biology, genetics and systematics. This study provides characterisation of the complete mitochondrial (mt) genome of C. Megalops. The complete mt genome of C. Megalops was obtained by long PCR, sequenced and annotated. The length of the entire mt genome of C. Megalops is 13,887 bp; it contains 12 protein-coding, 2 ribosomal RNA and 22 transfer RNA genes, but lacks an atp8 gene. The mt gene arrangement of C. Megalops is identical to that observed in Anoplocephala magna and A. perfoliata (Anoplocephalidae), Dipylidium caninum (Dipylidiidae) and Hymenolepis diminuta (Hymenolepididae), but differs from that reported in taeniids owing to the position shift between the tRNA (L1) and tRNA (S2) genes. The phylogenetic position of C. Megalops was inferred using Maximum likelihood and Bayesian inference methods based on the concatenated amino acid data for 12 protein-coding genes. Phylogenetic trees showed that C. Megalops is sister to Anoplocephala spp. (Anoplocephalidae) + Pseudanoplocephala crawfordi + Hymenolepis spp. (Hymenolepididae) indicating that the family Hymenolepididae is paraphyletic. The complete mt genome of C. Megalops is sequenced. Phylogenetic analyses provided an insight into the phylogenetic relationships among the families Anoplocephalidae, Hymenolepididae, Dipylidiidae and Taeniidae. This novel genomic information also provides the opportunity to develop useful genetic markers for studying the molecular epidemiology, biology, genetics and systematics of C. Megalops.
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Additional file 1: of Characterization of the complete mitochondrial genome of the cloacal tapeworm Cloacotaenia Megalops (Cestoda: Hymenolepididae)
2016Co-Authors: Aijiang GuoAbstract:Table S1. Primers used to amplify PCR fragments for Cloacotaenia Megalops. (DOC 37Â kb
Benine, Ricardo C. - One of the best experts on this subject based on the ideXlab platform.
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Figure 2 from: Soares IM, Azevedo-Santos VM, Benine RC (2017) Redescription of Moenkhausia Megalops (Eigenmann, 1907), a widespread tetra from the Amazon basin (Characiformes, Characidae). Zoosystematics and Evolution 93(2): 255-264. https://doi.org/10.3897/zse.93.10837
2017Co-Authors: Soares, Isabel M., Azevedo-santos, Valter M., Benine, Ricardo C.Abstract:Figure 2 - Moenkhausia Megalops, INPA 48895, 41.9 mm SL, Brazil, Amazonas State, rio Japurá basin
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Figure 1 from: Soares IM, Azevedo-Santos VM, Benine RC (2017) Redescription of Moenkhausia Megalops (Eigenmann, 1907), a widespread tetra from the Amazon basin (Characiformes, Characidae). Zoosystematics and Evolution 93(2): 255-264. https://doi.org/10.3897/zse.93.10837
2017Co-Authors: Soares, Isabel M., Azevedo-santos, Valter M., Benine, Ricardo C.Abstract:Figure 1 - Moenkhausia Megalops, holotype, CAS 71433, 40.6 mm SL, Brazil, Pará State, Itaituba, rio Tapajós basin. Figure modified from CAS, all rights reserved
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Figure 3 from: Soares IM, Azevedo-Santos VM, Benine RC (2017) Redescription of Moenkhausia Megalops (Eigenmann, 1907), a widespread tetra from the Amazon basin (Characiformes, Characidae). Zoosystematics and Evolution 93(2): 255-264. https://doi.org/10.3897/zse.93.10837
2017Co-Authors: Soares, Isabel M., Azevedo-santos, Valter M., Benine, Ricardo C.Abstract:Figure 3 - Scanning electronic micrography of dentition of Moenkhausia Megalops, INPA 40617, 43.2 mm SL, left internal lateral view of premaxilla, maxilla and dentary bones. Scale bar: 300µm
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Figure 4 from: Soares IM, Azevedo-Santos VM, Benine RC (2017) Redescription of Moenkhausia Megalops (Eigenmann, 1907), a widespread tetra from the Amazon basin (Characiformes, Characidae). Zoosystematics and Evolution 93(2): 255-264. https://doi.org/10.3897/zse.93.10837
2017Co-Authors: Soares, Isabel M., Azevedo-santos, Valter M., Benine, Ricardo C.Abstract:Figure 4 - Moenkhausia Megalops, GEA 2127, 61.4 mm SL, live specimen, Brazil, Pará State, rio Aurá, tributary of rio Guamá basin, Utinga State Park, Água Preta lake. Photo by M. Andrade
Soares, Isabel M. - One of the best experts on this subject based on the ideXlab platform.
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Figure 2 from: Soares IM, Azevedo-Santos VM, Benine RC (2017) Redescription of Moenkhausia Megalops (Eigenmann, 1907), a widespread tetra from the Amazon basin (Characiformes, Characidae). Zoosystematics and Evolution 93(2): 255-264. https://doi.org/10.3897/zse.93.10837
2017Co-Authors: Soares, Isabel M., Azevedo-santos, Valter M., Benine, Ricardo C.Abstract:Figure 2 - Moenkhausia Megalops, INPA 48895, 41.9 mm SL, Brazil, Amazonas State, rio Japurá basin
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Figure 1 from: Soares IM, Azevedo-Santos VM, Benine RC (2017) Redescription of Moenkhausia Megalops (Eigenmann, 1907), a widespread tetra from the Amazon basin (Characiformes, Characidae). Zoosystematics and Evolution 93(2): 255-264. https://doi.org/10.3897/zse.93.10837
2017Co-Authors: Soares, Isabel M., Azevedo-santos, Valter M., Benine, Ricardo C.Abstract:Figure 1 - Moenkhausia Megalops, holotype, CAS 71433, 40.6 mm SL, Brazil, Pará State, Itaituba, rio Tapajós basin. Figure modified from CAS, all rights reserved
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Figure 3 from: Soares IM, Azevedo-Santos VM, Benine RC (2017) Redescription of Moenkhausia Megalops (Eigenmann, 1907), a widespread tetra from the Amazon basin (Characiformes, Characidae). Zoosystematics and Evolution 93(2): 255-264. https://doi.org/10.3897/zse.93.10837
2017Co-Authors: Soares, Isabel M., Azevedo-santos, Valter M., Benine, Ricardo C.Abstract:Figure 3 - Scanning electronic micrography of dentition of Moenkhausia Megalops, INPA 40617, 43.2 mm SL, left internal lateral view of premaxilla, maxilla and dentary bones. Scale bar: 300µm
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Figure 4 from: Soares IM, Azevedo-Santos VM, Benine RC (2017) Redescription of Moenkhausia Megalops (Eigenmann, 1907), a widespread tetra from the Amazon basin (Characiformes, Characidae). Zoosystematics and Evolution 93(2): 255-264. https://doi.org/10.3897/zse.93.10837
2017Co-Authors: Soares, Isabel M., Azevedo-santos, Valter M., Benine, Ricardo C.Abstract:Figure 4 - Moenkhausia Megalops, GEA 2127, 61.4 mm SL, live specimen, Brazil, Pará State, rio Aurá, tributary of rio Guamá basin, Utinga State Park, Água Preta lake. Photo by M. Andrade
Otto Bismarck Fazzano Gadig - One of the best experts on this subject based on the ideXlab platform.
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the spiny dogfish squalus cubensis Megalops group the envenoming of a fisherman with taxonomic and toxinological comments on the squalus genus
Toxicon, 2005Co-Authors: Vidal Haddad, Otto Bismarck Fazzano GadigAbstract:The authors report a spiny dogfish (Squalus cubensis/Megalops group) sting of a professional fisherman. He was injured on the left hand by the spine anterior to the fish's dorsal fin and manifested local edema, erythema, and excruciating pain for 6 h. Sharks of the genus Squalus Megalops/cubensis and Squalus acanthias are found throughout the world; they have two spines in front of their dorsal fins and channels with a whitish mass containing large vacuolated cells which secrete venom. The Squalus genus has a complex taxonomy; the species involved in this injury belongs to the Megalops/cubensis group. A detailed taxonomic and toxinological study on the Squalus genus is important and would complement other work on these fish, especially as stings in humans are very rare and not fully understood.