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

Morphological and historical examinations of samples of Zenxis sp. were done to assess their health as well as the mangrove communities where they were sampled from. For the morphological examination, 20 randomly collected fresh samples of Zenxis sp. from two mangrove sites- one near and one away from an industrial zone ? were compared. Results show diversity in the shell integrity of Zenxis sp. discolorations of the shell were also found in the samples taken near an industrial zone. In the histological analysis, suspected tissue lessions of the mouth such as the accumulation of tar-like substance, compression of the outer mantle folds, deformation of the adipose cells, and proliferation of mucous cells were observed. In the gut tissue, occurrence of both engulfed, brown spherical bodies and lymphocycle-like basophilic bodies were observed in the samples. These observations suggest a diversity of morphological and histological characters. But whether these differences were due to individual variation, adaptations ro various environmental conditions, or as indicators of the effects of pollution is unknown