Ecology of the estuarine catfishes (fam: Ariidae) from the Matang Mangrove ecosystem.

This study was conducted in Sg. Selinsing to determine the distribution and abundance, and the utilization of the mangroves by the estuarine catfishes. The data showed that Arius maculatus was the most abundant ariid followed by Arius venosus, Arius utik and Arius caelatus. The combined ariid density and biomass was significantly different between diel (day and night) and phase (floods and ebbs) combinations during neap tides, being highest in the day-flood combination but was not significant during spring tides. During neap tides, the combined ariid density and biomass was significantly higher during floods (phase pattern of tides) but was not affected by day and night patterns (except for Arius truncatus). Spring tide catches did not show any significant difference of combined density and biomass during phase (floods and ebbs), and diel (day and night) patterns. The density and biomass of the ariid species was significantly higher during neap tides except for A. truncatus that had significantly higher density and biomass during spring tides. The data suggested that there was temporal separation rather than spatial separation of the ariids in Sg. Selinsing. Higher percentages of immature ariids were recorded suggesting that they utilize the mangroves as nursery grounds. Ketengus typus, Osteogeneiosus militaris and Arius venosus had reasonably high percentage of matured females and suggests that these ariids also utilize the mangroves as breeding grounds. The feeding ground function of the mangroves was also shown where a variety of diet types were recorded from stomach contents of the ariids