Biological parameters, ecology and population trends of the Mediterranean endemic skate, Raja polystigma, in the Balearic Islands

Elasmobranchs are a vulnerable group that has been overexploited for almost half a century in the Mediterranean. However, few elasmobranch species have been assessed because information on their basic biological parameters is lacking for most species. Raja polystigma is a poorly studied endemic skat...

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Detalles Bibliográficos
Autores: Ferragut-Perelló, Francesca, Valls, Maria, Cortes-Pujol, M.A., Ramírez-Amaro, Sergio, Guijarro, Beatriz, Ordines, Francesc
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/323074
Acceso en línea:http://hdl.handle.net/10261/323074
Access Level:acceso abierto
Palabra clave:Pesquerías
Centro Oceanográfico de Baleares
specled ray
biology
reproduction and condition
fish
islands
ecology
parameters
isobaths
Descripción
Sumario:Elasmobranchs are a vulnerable group that has been overexploited for almost half a century in the Mediterranean. However, few elasmobranch species have been assessed because information on their basic biological parameters is lacking for most species. Raja polystigma is a poorly studied endemic skate in the Mediterranean. The aim of this work is to determine some basic life history parameters of this skate in the Balearic Islands. Data were collected from commercial catches and during MEDITS surveys. Total length varied from 17 to 59 cm for both sexes, with a higher proportion of females than males. Allometric and morphometric relationships differed between sexes, females being heavier for a given size. Females matured at a larger size than males (L50 47.7 cm and 38.4 cm, respectively). Potential fecundity ranged between 11 and 45 yolked oocytes per female, and spawning was observed mainly during winter and spring. Persistent hotspots of adults and juveniles were detected on the shallow shelf off the northwest of Mallorca and east of Menorca, with adults being found mainly in the shallow and juveniles in deeper areas. Time series of abundance and frequency of appearance showed stable trends throughout the study period (2003-2018).