Maturation, fecundity and seasonality of reproduction of common cuttlefish (Sepia officinalis L. 1758), in Antalya Bay

ABSTRACT MATURATION, FECUNDITY AND SEASONALITY OF REPRODUCTION OF COMMON CUTTLEFISH (SEPIA OFFICINALIS L. 1758), IN ANTALYA BAY Olgaç GÜVEN M.Sc. in Engineering of Aquatic Products Adviser: Asst. Prof. Dr. Mehmet ÖZBAŞ June, 2004, 65 pages In this study maturity, fecundity and seasonality of reproduction of common cuttlefish [Sepia officinalis L. 1758) were studied between 1st September 2002 and 23rd March 2004, which were collected from Antalya Bay. The samples were caught by commercial bottom trawl. Between 1st April 2003 and 1st September 2003 gill nets are used according to the policy of fisheries. 490 individuals are collected during the study. The mantle lengths and total weights of common cuttlefish varied from 55 - 177 mm, 29.7 - 652.3 g for females and 45 - 170 mm, 16. 8-510. 8g for males respectively. The mean total mantle lenght and body weight for females and males are 105 ±1.6 mm, 174.83 ± 7.79 g and 98.8 ± 0.15 mm, 135.46 ± 5.65 g respectively. Four maturity stages were described using morphology and histology. Based on the proportions of each maturity stage, as well as various maturity indices, spawning was found to take place from may to august. The size at maturity for Sepia officinalis was 66 and 67 mm for females and males, respectively. Fecundity was estimated by counting the number of mature and maturing ova which varied from 50 to 543. Mean value of ova is 183.2 ± 9.58. mKEYWORDS: Antalya Bay, common cuttlefish, Sepia officinalis, fecundity, maturity, seasonality of reproduction. COMMITTEE: Asst. Prof. Dr. Mehmet ÖZBAŞ Prof. Dr. Beria FALAKALI MUTAF Prof. Dr. Mehmet ÖZ IV