Age, growth, reproductive biology and feed of the common guitarfish (Rhinobatos rhinobatos Linnaeus, 1758) in Iskenderun Bay, the eastern Mediterranean Sea

摘要

The age, growth, reproduction, and feeding of common guitarfish (Rhinobatos rhinobatos) were studied using 225 specimens from the Iskenderun Bay, (eastern Mediterranean). Females made up 43% and males 57% of the individuals. The total length of females ranged from 22.2 to 81 cm, and of males from 22 to 120 cm. The total length-weight relationships was W = 0.0036 x TL super(2.93). The age data, derived from vertabrae readings, were used to estimate the growth parameters of the von Bertalanffy equation: L sub([infinity]) = 128.6 cm, K = 0.29, t sub(0) = -0.89. The maximum age was 5 years. The parturition time of common guitarfish occurred in summer (from May to September). The mean TL and mean weight of developed fetuse were 25.7 cm TL and 48.5 g, respectively. Males matured at 68 cm TL and females at 69 cm TL. The stomachs contained mainly Crustacea.