Population structure of an endemic fish Limia zonata (Cyprinodontiformes: Poeciliinae) in the Maimón River, Dominican Republic

Abstract

The population structure of Limia zonata (Nichols, 1915) was studied in four locations in the Maimón River, Monseñor Nouel province, Dominican Republic. The sex and adult-juveniles ratio was calculated for all sampled localities. It was found that the sex ratio of L. zonata was significantly different from 1: 1 and is biased towards females (1.0: 1.6). Juvenile fish were more abundant and frequent than adults (69.3%). More than 800 fish were measured and weighed to analyze the frequency of size classes, morphometry and body condition. Ten size classes were distinguished that vary in frequency according to sex. Total length of the specimens ranged from 6.50 to 65.69 mm, while weight varied between 0.004 and 3.941 g. The morphology varied between sexes and a pronounced sexual dimorphism was found. All the morphometric variables studied showed a high level of association (r). The adjustment of the regression models (r2) of the morphometric relationships was between 85% and 99%. The relationship between the standard length and the total weight was reflected in the rates of growth. The Relative Condition Factor (Kn) demonstrated the good state of health of this fish population, but also variations between the sexes were detected.