Some biological parameters of the peacock wrasse, Symphodus (Crenilabrus) tinca (L. 1758) (Pisces: Labridae) from the middle eastern Adriatic (Croatian coast)

Abstract

Data on sex ratio, length-weight relationship, age, growth and survival rate were analysed for peacock wrasse, Symphodus (Crenilabrus) tinca L., (total = 1443; males = 848, females = 595) collected in the eastern middle Adriatic island area during the reproductive period (April and May) from 1995 to 1999. The total length of sampled specimens ranged from 8.9 to 42.5 cm and the weight from 7.9 to 764.2 g. The overall sex ratio was 1.43:1 in favour of males. All individuals larger than 28.9 cm were males as an effect of faster growth. The oldest females were 12 and the oldest males 13 years old. The von Bertalanffy growth formula was estimated for females (L_∞ = 28.14; k = 0.294; t₀ = - 0.775) and males (L_∞ = 42.24; k = 0.214; t₀ = - 0.628). The slopes (b values) of total length - weight regressions indicated allometric growth for males (b = 2.7205) and both sexes (b = 2.8147) and isometric growth for females (b = 2.9901). Survival rate of males (S = 0.80) was slightly greater than that for females (0.756).