Age, growth and demography of the silky shark Carcharhinus falciformis from the southwestern Atlantic
The silky shark Carcharhinus falciformis is considered one of the least productive pelagic shark species. The estimation of growth and demographic parameters presented here is fundamental to a sound knowledge of population status of the species in the Atlantic Ocean. Data was collected through an on...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Inter-Research
2021-07-01
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| Series: | Endangered Species Research |
| Online Access: | https://www.int-res.com/abstracts/esr/v45/p237-249/ |
| _version_ | 1823936157489037312 |
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| author | J Santander-Neto R Barreto FM Santana RPT Lessa |
| author_facet | J Santander-Neto R Barreto FM Santana RPT Lessa |
| author_sort | J Santander-Neto |
| collection | DOAJ |
| description | The silky shark Carcharhinus falciformis is considered one of the least productive pelagic shark species. The estimation of growth and demographic parameters presented here is fundamental to a sound knowledge of population status of the species in the Atlantic Ocean. Data was collected through an onboard observer program of the Brazilian chartered pelagic longline fishing fleet that operates in the Equatorial Southwestern Atlantic. Vertebral analysis produced the von Bertalanffy growth parameters for pooled sexes L∞ = 283.05 cm; k = 0.0987 yr-1 and t0 = -3.47 yr. Males reached sexual maturity at 8.6 yr and females at 9.9 yr. Longevity was estimated at 27.2 yr. Age structure analysis indicated that 80.5% of the catch was composed of juveniles, with recruitment to the fishery from the first year of life (age 1+). These biological parameters are responsible for the species’ low resistance to fishing pressure, and our demographic analysis (Leslie Matrix) shows an annual population decline of 12.7% yr-1 under the current fishing scenario for the period analyzed. Therefore, conservation measures must be enacted to reestablish the population of silky sharks to safe levels for the maintenance of this species in the South Atlantic. |
| first_indexed | 2024-12-16T22:46:03Z |
| format | Article |
| id | doaj.art-8502c8099da24016b9fe446f41dc5b1d |
| institution | Directory Open Access Journal |
| issn | 1863-5407 1613-4796 |
| language | English |
| last_indexed | 2024-12-16T22:46:03Z |
| publishDate | 2021-07-01 |
| publisher | Inter-Research |
| record_format | Article |
| series | Endangered Species Research |
| spelling | doaj.art-8502c8099da24016b9fe446f41dc5b1d2022-12-21T22:13:14ZengInter-ResearchEndangered Species Research1863-54071613-47962021-07-014523724910.3354/esr01131Age, growth and demography of the silky shark Carcharhinus falciformis from the southwestern AtlanticJ Santander-Neto0R Barreto1FM Santana2RPT Lessa3Instituto Federal de Educação, Ciência e Tecnologia do Espírito Santo (Ifes), Campus Piúma, Laboratório de Dinâmica de Populações Marinhas do Espírito Santo, CEP 29285-000, Piúma - ES, BrazilCentro Nacional de Pesquisa e Conservação da Biodiversidade Marinha do Sudeste e Sul do Brasil (ICMBio-CEPSUL), CEP 88301-445, Itajaí - SC, BrazilUniversidade Federal Rural de Pernambuco (UFRPE), Unidade Acadêmica de Serra Talhada (UAST), Laboratório de Dinâmica de Populações Aquáticas (DAQUA), CEP56909-535, Serra Talhada - PE, BrazilUniversidade Federal Rural de Pernambuco (UFRPE), Departamento de Pesca e Aqüicultura (DEPAq), Laboratório de Dinâmica de Populações Marinhas (DIMAR), CEP 52171-900, Recife - PE, BrazilThe silky shark Carcharhinus falciformis is considered one of the least productive pelagic shark species. The estimation of growth and demographic parameters presented here is fundamental to a sound knowledge of population status of the species in the Atlantic Ocean. Data was collected through an onboard observer program of the Brazilian chartered pelagic longline fishing fleet that operates in the Equatorial Southwestern Atlantic. Vertebral analysis produced the von Bertalanffy growth parameters for pooled sexes L∞ = 283.05 cm; k = 0.0987 yr-1 and t0 = -3.47 yr. Males reached sexual maturity at 8.6 yr and females at 9.9 yr. Longevity was estimated at 27.2 yr. Age structure analysis indicated that 80.5% of the catch was composed of juveniles, with recruitment to the fishery from the first year of life (age 1+). These biological parameters are responsible for the species’ low resistance to fishing pressure, and our demographic analysis (Leslie Matrix) shows an annual population decline of 12.7% yr-1 under the current fishing scenario for the period analyzed. Therefore, conservation measures must be enacted to reestablish the population of silky sharks to safe levels for the maintenance of this species in the South Atlantic.https://www.int-res.com/abstracts/esr/v45/p237-249/ |
| spellingShingle | J Santander-Neto R Barreto FM Santana RPT Lessa Age, growth and demography of the silky shark Carcharhinus falciformis from the southwestern Atlantic Endangered Species Research |
| title | Age, growth and demography of the silky shark Carcharhinus falciformis from the southwestern Atlantic |
| title_full | Age, growth and demography of the silky shark Carcharhinus falciformis from the southwestern Atlantic |
| title_fullStr | Age, growth and demography of the silky shark Carcharhinus falciformis from the southwestern Atlantic |
| title_full_unstemmed | Age, growth and demography of the silky shark Carcharhinus falciformis from the southwestern Atlantic |
| title_short | Age, growth and demography of the silky shark Carcharhinus falciformis from the southwestern Atlantic |
| title_sort | age growth and demography of the silky shark carcharhinus falciformis from the southwestern atlantic |
| url | https://www.int-res.com/abstracts/esr/v45/p237-249/ |
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