Parasitic Helminths from Dead Stranded Dugong, Dugong Dugon (Muller, 1976), in Dahican, Mati city, Mindanao, The Philippines

Abstract

Two dugongs, Dugong dugon (Muller, 1976), were accidentally entangled in fishing nets in Barangay Dahican, Mati City, Southeastern Mindanao, Philippines. These dugongs, 2.2 and 2.5m in length and 172 and 132.5kg in weight respectively, were necropsied in January and February 2011, and a parasitological examination was conducted on each. From one dugong, adult roundworms, Paradujardinia halicoris and trematodes, Solenorchis travassosi (syn. Indosolenorchis hirudinaceus) were recovered from the stomach or small intestine and caecum respectively. From the other, juvenile roundworms were found in the stomach and small intestine. Female adults were 104.7mm long and 3.1mm wide on average, whereas male adults were similarly 97.6mm long and 2.8mm wide. Scanning Electron Microscopy (SEM) of P. halicoris showed that this nematode had three well-defined lips, longer than the width, with small triangular interlabia between them, distinctly offset from the anterior end. A few trematodes, S. travassosi, were 10.3mm long and 3.1mm wide on average with a tiny oral sucker and a large posterior sucker subterminally located at both extremities. The posterior extremity has a distinct crescent-like muscular projection on its end. This is the first confirmed record of two helminth species from dugongs around Mindanao Island.