Morphology of Goby Species, Glossogobius celebius (Valenciennes 1837) and Glossogobius giuris (Hamilton 1822) in Lake Lanao Mindanao, Philippines

Abstract

Morphological differences between two introduced species of freshwater gobies, Glossogobius celebius (Valenciennes 1837) and Glossogobius giuris (Hamilton 1822) were investigated in Lake Lanao. To achieve this, 24 morphometric measurements were made on each of the studied fish specimens (27 Glossogobius celebius and Glossogobius giuris). The results showed that the entire morphometric characters measured in both sexes within the two species were not significantly different (P<0.05), male and female were not sexually dimorphic with apparent distinctions on their morphological attributes, particularly on their differences in sizes and lengths. And with the body proportionality between sexes of G. celebius, females compared to males had a relatively higher percentage of uncorrelated morphometric character which implies that the females’ morphological attributes may have experienced slight changes over the Lake Lanao and males’ morphological attributes were highly proportional regardless of their spatial distribution. With these, well-proportioned body structure in males would illustrate an attractive physical attribute that may help in the courtship of males to females. Meanwhile, in Glossogobius giuris body proportionality between the two sexes was in contrast with the Glossogobius celebius for the males were the ones to have a higher percentage of uncorrelated morphometric character than females. The results can provide a solid base for the identification, rational management, breeding and conservation of the two fish species.