Bioecological aspects of 561 M. incilis captured by casts-net (75.4%) and gill net (24.6%) in Cispata bay, between July and December 2007 were determined. Total length (TL) was between 17.5 to 44.5 cm TL, most of the individuals were juvenile, which is reflected in the allometric growth: W (g) = 0.01 TL (cm)2.83 (r2 = 0.92). 48% were males (n = 221) and 52% females (n = 240); there was no significant deviations of the 1:1 sex ratio (χ2 = 0.39; p = 0.53). Maturity size was estimated on 30.5 cm TL for both sexes, 30.3 cm TL for females (n = 188) and 35.6 for males (n = 231). Gonadosomatic and hepatosomatic indices increased at the end of the year, in the same way as the gonad development stages III, IV and V, suggesting a reproductive peak of M. incilis. Out of the 177 fishes examined, it was determined that 65% contained parasites, with an abundance of 3.4 ± 0.5 parasites/fish and a mean intensity of 5.4 endoparasites/infected fish. Parasitic fauna were identified as: Ergasilus sp., Caligus sp., Contracaecum sp. and Acantocephalans; although the latter group is not considered a pathogen, further research is necessary to explain its representation. From the information generated, a fisheries management improvement was suggested for M. incilis in Cispata bay.