Reproductive strategy and population structure of Centroscymnus coelolepis (Chondrichthyes: somniosidae) : a scientific support for management advice
Tese de doutoramento, Ciências do Mar, Universidade de Lisboa, Faculdade de Ciências, 2012 The Portuguese dogfish Centroscymnus coelolepis is a deep-water shark commonly caught in the Northeast Atlantic that shows a decreasig trend in its abundance, in special in the northern areas. Assessment of th...
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ftunivlisboa:oai:repositorio.ul.pt:10451/5485 2023-05-15T17:41:24+02:00 Reproductive strategy and population structure of Centroscymnus coelolepis (Chondrichthyes: somniosidae) : a scientific support for management advice Moura, Maria Teresa Narciso Simões da Silva, 1980- Gordo, Leonel Serrano, 1957- Figueiredo, Ivone, 1960- 2012-03-06T17:15:07Z http://hdl.handle.net/10451/5485 eng eng http://hdl.handle.net/10451/5485 restrictedAccess Carocho Centroscymnus coelolepis Reprodução Desenvolvimento embrionário Crescimento Genética populacional Teses de doutoramento - 2012 doctoralThesis 2012 ftunivlisboa 2022-05-25T18:32:02Z Tese de doutoramento, Ciências do Mar, Universidade de Lisboa, Faculdade de Ciências, 2012 The Portuguese dogfish Centroscymnus coelolepis is a deep-water shark commonly caught in the Northeast Atlantic that shows a decreasig trend in its abundance, in special in the northern areas. Assessment of this species has been difficult due to the poor knowledge on its dynamics, including its reproductive strategy and population structure. The present thesis pretends to fill some gaps by providing scientific support to be used in the advisement of this resource. C. coelolepis presents two peaks of ovulation in each year (March-May and September-November). Each female produces, in average, 12 embryos. The embryonic development may last two years and analyses suggest that only water and minerals are transferred from the mother to the embryo. Thus, C. coelolepis is a viviparous species, strictly lecithotrophic, depending only on yolk reserves for the embryonic development. Both males and females are able to store sperm: in males, sperm is stored in the seminal vesicle from early maturity stages until mating; mature, pregnant, resting and regenerating females store sperm in the terminal zone of the oviducal gland within sperm storage tubules, possibly for a long time period. A fraction of the population seems to distribute in areas where the fishery has no impact, due, in part, to the existence of sexual segregation among specimens. This species can be aged using dorsal spines. The population under study presents slow growth rates, high longevity and late maturity. The COI gene has proved to be an adequate marker to identify C. coelolepis, when doubts on identification arise. The hypothesis of existence of a single population in the Northeast Atlantic was not rejected, after the analysis of control region and six microsatellite markers. However, the possibility of existence of philopatry is not excluded. O carocho, Centroscymnus coelolepis, é um tubarão de profundidade com uma distribuição global, ocorrendo nos oceanos ... Doctoral or Postdoctoral Thesis Northeast Atlantic Universidade de Lisboa: repositório.UL |
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Open Polar |
collection |
Universidade de Lisboa: repositório.UL |
op_collection_id |
ftunivlisboa |
language |
English |
topic |
Carocho Centroscymnus coelolepis Reprodução Desenvolvimento embrionário Crescimento Genética populacional Teses de doutoramento - 2012 |
spellingShingle |
Carocho Centroscymnus coelolepis Reprodução Desenvolvimento embrionário Crescimento Genética populacional Teses de doutoramento - 2012 Moura, Maria Teresa Narciso Simões da Silva, 1980- Reproductive strategy and population structure of Centroscymnus coelolepis (Chondrichthyes: somniosidae) : a scientific support for management advice |
topic_facet |
Carocho Centroscymnus coelolepis Reprodução Desenvolvimento embrionário Crescimento Genética populacional Teses de doutoramento - 2012 |
description |
Tese de doutoramento, Ciências do Mar, Universidade de Lisboa, Faculdade de Ciências, 2012 The Portuguese dogfish Centroscymnus coelolepis is a deep-water shark commonly caught in the Northeast Atlantic that shows a decreasig trend in its abundance, in special in the northern areas. Assessment of this species has been difficult due to the poor knowledge on its dynamics, including its reproductive strategy and population structure. The present thesis pretends to fill some gaps by providing scientific support to be used in the advisement of this resource. C. coelolepis presents two peaks of ovulation in each year (March-May and September-November). Each female produces, in average, 12 embryos. The embryonic development may last two years and analyses suggest that only water and minerals are transferred from the mother to the embryo. Thus, C. coelolepis is a viviparous species, strictly lecithotrophic, depending only on yolk reserves for the embryonic development. Both males and females are able to store sperm: in males, sperm is stored in the seminal vesicle from early maturity stages until mating; mature, pregnant, resting and regenerating females store sperm in the terminal zone of the oviducal gland within sperm storage tubules, possibly for a long time period. A fraction of the population seems to distribute in areas where the fishery has no impact, due, in part, to the existence of sexual segregation among specimens. This species can be aged using dorsal spines. The population under study presents slow growth rates, high longevity and late maturity. The COI gene has proved to be an adequate marker to identify C. coelolepis, when doubts on identification arise. The hypothesis of existence of a single population in the Northeast Atlantic was not rejected, after the analysis of control region and six microsatellite markers. However, the possibility of existence of philopatry is not excluded. O carocho, Centroscymnus coelolepis, é um tubarão de profundidade com uma distribuição global, ocorrendo nos oceanos ... |
author2 |
Gordo, Leonel Serrano, 1957- Figueiredo, Ivone, 1960- |
format |
Doctoral or Postdoctoral Thesis |
author |
Moura, Maria Teresa Narciso Simões da Silva, 1980- |
author_facet |
Moura, Maria Teresa Narciso Simões da Silva, 1980- |
author_sort |
Moura, Maria Teresa Narciso Simões da Silva, 1980- |
title |
Reproductive strategy and population structure of Centroscymnus coelolepis (Chondrichthyes: somniosidae) : a scientific support for management advice |
title_short |
Reproductive strategy and population structure of Centroscymnus coelolepis (Chondrichthyes: somniosidae) : a scientific support for management advice |
title_full |
Reproductive strategy and population structure of Centroscymnus coelolepis (Chondrichthyes: somniosidae) : a scientific support for management advice |
title_fullStr |
Reproductive strategy and population structure of Centroscymnus coelolepis (Chondrichthyes: somniosidae) : a scientific support for management advice |
title_full_unstemmed |
Reproductive strategy and population structure of Centroscymnus coelolepis (Chondrichthyes: somniosidae) : a scientific support for management advice |
title_sort |
reproductive strategy and population structure of centroscymnus coelolepis (chondrichthyes: somniosidae) : a scientific support for management advice |
publishDate |
2012 |
url |
http://hdl.handle.net/10451/5485 |
genre |
Northeast Atlantic |
genre_facet |
Northeast Atlantic |
op_relation |
http://hdl.handle.net/10451/5485 |
op_rights |
restrictedAccess |
_version_ |
1766142924395905024 |