First Finding of High Infestation of Nemesis robusta on Gill Filaments of Alopias pelagicus from the Andaman Sea, Thailand

Abstract

Parasitic copepod, Nemesis robusta, was firstly found in the pelagic thresher (Alopias pelagicus) in the Andaman Sea between the depths of 500-1,000 m. The pelagic threshers were highly infested with N. robusta at the distal part of gill filaments. Mean intensity was 39.25 individuals per shark. The copulatory activity of this parasite was also found. Such high infestation occurred only in this shark which may be a seasonal occurrence.