Size and sex composition of two species of the genus Atlantoraja (Elasmobranchii, Rajidae) caught by the bottom trawl fisheries operating on the Uruguayan continental shelf (southwestern Atlantic Ocean)

  • Luis Orlando Dirección Nacional de Recursos Acuáticos; Departamento de Biología Pesquera
  • Ines Pereyra Dirección Nacional de Recursos Acuáticos; Departamento de Biología Pesquera
  • Laura Paesch Dirección Nacional de Recursos Acuáticos; Departamento de Biología Pesquera
  • Walter Norbis Laboratorio de Fisiología de la Reproducción y Ecología de Peces; Departamento de Biología Animal; Facultad de Ciencias
Keywords: Skates, Exploitation vulnerability, Population, Spatial-temporal patterns

Abstract

In this work we analyzed the spatial and seasonal variation of length distribution, sexual proportion and mature dominance for Atlantoraja cyclophora and A. castelnaui, at the Uruguayan continental shelf. There were significant differences in total length (TL) composition between sexes, being females bigger than males for both species. Atlantoraja cyclophora showed a relatively uniform length distribution between inner and outer shelf. There were no major variations in the sex compositions and in the mature dominance between seasons, suggesting no temporal variation. Atlantoraja castelnaui showed a significant variation in its spatial and seasonal distribution. Individuals were smaller in inner shelf, pointing out the existence of juvenile zone in areas up to 50 m depth. A tendency to capture smaller individuals towards the end of the year was observed. In all seasons over 50% of females were caught below the estimated size at maturity, suggesting that this species is highly susceptible to exploitation.

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Published
2011-12-01
How to Cite
Orlando, L., Pereyra, I., Paesch, L., & Norbis, W. (2011). Size and sex composition of two species of the genus Atlantoraja (Elasmobranchii, Rajidae) caught by the bottom trawl fisheries operating on the Uruguayan continental shelf (southwestern Atlantic Ocean). Brazilian Journal of Oceanography, 59(4), 357-364. https://doi.org/10.1590/S1679-87592011000400006
Section
naodefinida