SISTEMATICA, BIOLOGIA Y ECOLOGIA DEL TITI Sicydium antillarum Grant (PISCES: GOBIIDAE) EN LA REGION DE SANTAMARTA, COLOMBIA

Abstract

Sicydiumantillarum Grant isan abundant gobiid fish in the streams which runfrom theSierra Nevada de Santa Marta (Colombia) to the sea. The population living in the Quebrada Valencia was studied from February 1987 to January 1988; postlarvae were observed and collected at the mouths of the Manzanares and Gaira rivers. Morphological, meristic and morphometric data of the species are presented; the population spawned between May and December, with peaks in June and October. Sex ratios between January and March were around 1:1; males defend a territory from April to December and are more difficult to capture (mainly in September and October, when the ratios are about nine females per male). The highest number of eggs (91,067) was found in a female 109 mm in length. Twenty-five per cent of the specimens reached maturity between 60.0 and 64.9 mm. The equation relating length (mm) and weigth (gr) is: Weigth = 1.0309x10~6 xtotal length 3*5232 . Condition factor reached a low value in November, that is after the highest spawning peak of the rainy season. The stomach contents studied were composed of algae and bacteria; all the specimens collected at 15:00 had a full stomach, which indicates that the species is diurnal. Postlarvae were detected monthly from August to December, always related to the waning moon. Adults and postlarvae are very hardy and live well in laboratory conditions.