Infestation of Some Marine Fish Species with Red Worm Philometra PDF

Keywords

Fish, marine water, Arabian Gulf, Philometra, seasonal variations, infestation, pathology.

Abstract

Over a two-year period, November 2006 to October 2008, the distribution of philometra sp. among host tissues was investigated in 10 host species collected from some coastal waters areas of the Arabian Gulf, Kingdom of Saudi Arabia. The examined fish species were: Epinephelus chlorostigma, Epinephelus tauvina, Johnius maculates, Lethrinus nebulosus, Lutjanus ehrenbergi, Psettodes erumei, Scomberomorus commerson, Siganus canaliculatus, Trichiurus lepturus and Tylosurus crocodiles. The overall percent of philometra sp. infestation among the examined fish species reached 9.5%. However, the infestation percentages in E. tauvina, L. nebulosus and E. chlorostigma, reached 24.13, 21.87 and 20 respectively, whereas in the rest of the examined fish species it was 0%. Generally, philometra sp. infestation rates showed seasonal variations, peaked in summer (25.92%), followed by the spring season (24.48%), winter season (21.21%) and autumn season (13.88%). The distribution of philometra sp. in tissues of infested fish species revealed its significant existence in the abdominal cavity and gonads. However, infestation rates in muscles and fin tissue were markedly and significantly low. Regarding histo-pathological alterations, infected ovaries appeared black, shrunken and changed to fibrous tissue. Degenerative changes and inflammatory cell proliferation wereobserved, however, in cases of chronic infestation, the dead parasite in the ovarian tissue initiated strong tissue response and proliferated connective tissue reaction as well as hyaline degeneration. Consequently, reduced in the volume of the affected ovaries and finally damage to the reproductive system were frequently seen.