Sexual maturation, age and growth of striped sea bream, Lithognathus mormyrus L., on the eastern coast of the Adriatic sea

Striped sea bream, Lithognathus mormyrus L., are hermaphoroditic protandrous fish. Sex ratios are given for length and age classes, indicating the males change sex mainly at lengths between 25.0 and 32.5 cm, in age classes 4 to 7, with more than 30% of the population changing sex in age class 6 to 7. Males were also observed up to a length of 34.5 cm. Length-weight relationship showed no significant difference from isometric growth in winter (b = 3.05) and a negative allometric growth in summer (b = 2.69). The age composition was established using the Bhattacharya method and additional observations of annual rings on scales. Six age classes were obtained from Kaštela Bay (age 3: 21.7 cm, age 4: 26.5 cm, age 5: 28.4 cm, age 6: 30.3 cm, age 7: 31.6 cm, age 8: 33.4 cm) and from Mirna Bay (age 2.5: 19.4 cm, age 3.5: 24.1 cm, age 4.5: 26.9, age 5.5: 29.4 cm, age 6.5: 31.3 cm, age 7.5: 32.8 cm). Von Bertalanffy's growth equation was fitted to these mean length-at-age data resulting in parameter values of L∞= 36.2 cm, K = 0.297, t0=−0.08 for Kašela Bay and L∞= 37.3 cm, K = 0.262, t0=−0.39 for Mirna Bay.