Abundance, reproductive period, and feeding habits of eleotrid fishes in estuarine habitats of north‐east Brazil

Abstract

Aspects of the abundance, reproduction, and feeding habits of Dormitalor maculatus, Eleotris pisonis, and Guavina guavina were assessed in the shallow waters of the Mundaú/Manguaba estuarine system, north‐east Brazil. Dormitator maculatus, the most abundant species, was caught in salinities ranging from 0·1 to 20·3 ppt and temperatures from 25·0 to 36·0° C. Eleotris pisonis, the second most abundant species, occurred in salinities from 0·1 to 18·2 ppt and temperatures from 25·0 to 33·0° C. Guavina guavina was rare at the stations sampled. Peak gonadal development was found during the winter (wet season) in D. maculatus and E. pisonis, and probably may occur during this season in G. guavina. Size‐at‐maturity was 51 and 46 mm T.L. for males and females of D. maculatus, respectively, and 57 and 43 mm T.L. for males and females of E. pisonis, respectively. Dormitator maculatus was omnivorous, and ingested primarily macrophytes, followed by sediment, and unidentified eggs; E. pisonis and G. guavina were predaceous, with the former preying mainly upon the gastropod Neritina virginea, and the latter mainly upon the crab Goniopsis cruentata. Dormitator maculatus and E. pisonis appear to coexist because of differences between the two in microhabitat and food utilization. The two more similar species, E. pisonis and G. guavina appear to coexist due to differences in spatial distribution.