Ecological insights into the Frillfin Goby in Badagry Creek, Lagos, Nigeria

Abstract

A study was conducted in Badagry Creek in Lagos, Nigeria on food and feeding habits and
reproduction of Frillfin goby (Bathygobius soporator). Data collected from the study intend to serve as
a baseline for carrying out further study on the fishes and fisheries of this water body. B. soporator is
one of the numerous and diverse fishes of the family Gobiidae which share certain similarities in their
life histories. Gobies are among the most successful fishes. They are resident intertidal species which
could be found in pools, rocky pools, lagoons, creeks and estuaries. Specimens were collected from
the Badagry Creek via Oto-Awori Fish Jetty between January, 2008 and January, 2009. Foods and
feeding habits and reproduction were studied in this creek. Seven groups of food items were
encountered in the stomachs of the fish, viz; Crustaceans, Pisces, Insects, Detritus, Bivalves,
unidentified food materials and Gastropods. The most eaten of these were the crustaceans contributing
34% by number and 38.30% by frequency of occurrence. The presence of other fish species in the
stomachs explained the piscivorous habit while the unidentified food materials demonstrate its
herbivorous character. Its predatory and carnivorous tendency was exhibited by the presence of
insects, bivalves, crustaceans, and gastropods. Presence of sand grains was an indicator of its benthic
nature. The specimens were classified as either male or female. Four hundred and seventy and five
specimens representing 98.95 and 1.05% of total catch were classified as males and females,
respectively giving 1 (male): 0.01 (female) sex ratio. This is significantly different (P>0.05) from the
expected or theoretical one male:one female ratio and not in conformity with sex ratios that were
reported for some fishes in the adjacent Ologe, Lagos, Lekki and Epe lagoons which favoured more
females. The Gonadosomatic index (GSI) of this species varied from 0.00 to 2.89%, meaning less than
2.89% of the fish’s body mass was converted to gonads for reproduction. The pre-spawning and
spawning stages of this species contributed 86.75 and 13.25% of the specimens, respectively. Post
spawning stages were absent.