Thesis (BS Biology) -- University of the Philippines Mindanao, 2002

Fiddler crab (Uca sp.) collected from areas near and away from an industrial zone were examined. Gross morphological examination of the carapace color, carapace integrity and gill color showed no, significant differences between the crabs in the two areas. However, gill lamellae were significantly shorter and lamellae fold membrane significantly thicker in the Brgy. Tambo samples than those in San Isidro. These differences can be necessary adaptations of the crustacean to certain stressors found in the area proximal to an industrial zone. Shorter gill lamellae enable faster gas exchange between respiratory structures and metabolic tissues or organs. On the other hand, thicker lamellae fold membrane is considered a defense mechanism against harmful substances in polluted a defense mechanism against harmful substance in polluted waters. The findings may suggest that Uca sp. can be potential biological indicator in evaluating the quality of the mangrove ecosystems in Davao Gulf