Reproductive biology of Raja clavata (Elasmobranchii: Rajidae) from Southern Black Sea coast around Turkey


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SAĞLAM H. , AK O.

HELGOLAND MARINE RESEARCH, cilt.66, ss.117-126, 2012 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 66 Konu: 2
  • Basım Tarihi: 2012
  • Doi Numarası: 10.1007/s10152-011-0252-5
  • Dergi Adı: HELGOLAND MARINE RESEARCH
  • Sayfa Sayıları: ss.117-126

Özet

Specimens of Raja clavata were monthly collected at the coast of HavaalanA +/- (Trabzon/Turkey) from January 2009 to December 2009 at depths between 20 and 40 m. A total of 230 individuals of thornback ray (131 females and 99 males) were collected by bottom trawls during research cruises. Using logistic regression, it was determined that TL at 50% maturity of males was 718 mm TL and of females 746 mm TL. The ovarian fecundity ranged from 27 to 60 yellow follicles in both ovaries. Females carrying egg cases were found in July and October. Variations in the gonadosomatic and hepatosomatic indices indicated a continuous reproductive cycle during the year.