Striped seabream Lithognathus mormyrus [n = 1269; total lengths (TLs) = 112-350 mm] were investigated in two coastal Sicilian fishing grounds (central Mediterranean Sea). Samples were collected from the two landing harbours, Licata and Selinunte, between October 1999 and September 2000. Seasonal and spatial variations in population structure, age, growth, reproduction and mortality were studied. It was found that seasonal differences in the main modes of length- frequency distributions corresponded well with the seasonal growth. The recruits in Licata grew faster and attained a larger size (by 10-20 mm) at ages up to 2 years than in Selinunte. Growth thereafter was relatively slow, with Selinunte specimens growing at a slightly faster rate. Spawning occurred between June and August. Length at the first maturity was different between females and males in the Selinunte (190- 181 mm) and Licata (183-171 mm) fishing grounds. The species displayed protandrous hermaphroditism, and somatic growth practically ceased during the period of sex inversion. Total fishing mortality was considerably higher in Licata (F between 0.53 and 0.63 per year) than in Selinunte (F between 0.22 and 0.29 per year). Therefore it is suggested that the striped seabream population in Licata is more vulnerable to overfishing than that in Selinunte.
Life history traits of the striped seabream Lithognathus mormyrus (Pisces, Sparidae) from two coastal fishing grounds in the Strait of Sicily.
Vitale S;Cannizzaro L;
2011
Abstract
Striped seabream Lithognathus mormyrus [n = 1269; total lengths (TLs) = 112-350 mm] were investigated in two coastal Sicilian fishing grounds (central Mediterranean Sea). Samples were collected from the two landing harbours, Licata and Selinunte, between October 1999 and September 2000. Seasonal and spatial variations in population structure, age, growth, reproduction and mortality were studied. It was found that seasonal differences in the main modes of length- frequency distributions corresponded well with the seasonal growth. The recruits in Licata grew faster and attained a larger size (by 10-20 mm) at ages up to 2 years than in Selinunte. Growth thereafter was relatively slow, with Selinunte specimens growing at a slightly faster rate. Spawning occurred between June and August. Length at the first maturity was different between females and males in the Selinunte (190- 181 mm) and Licata (183-171 mm) fishing grounds. The species displayed protandrous hermaphroditism, and somatic growth practically ceased during the period of sex inversion. Total fishing mortality was considerably higher in Licata (F between 0.53 and 0.63 per year) than in Selinunte (F between 0.22 and 0.29 per year). Therefore it is suggested that the striped seabream population in Licata is more vulnerable to overfishing than that in Selinunte.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
