Gastrointestinal Helminth Parasites Community of Fish Species in a Niger Delta Tidal Creek, Nigeria

A pool of fish species in a Niger Delta tidal creek, Buguma Creek, Nigeria, collected monthly from November 2004 to June 2006, at flood tides, were examined for gastrointestinal helminth parasites. The fish species were caught with hooks and lines and cast nets. Only nematode parasites were encountered in the study. Of the 1,149 fish specimens examined, 213 (representing 18.5%) were infected with various nematodes parasites. Dasyatis margarita had the highest prevalence rate of 66.7% (2 infected out of 3 examined), followed by Pseudotolithus (Pseudotolithus) senegalensis with a prevalence of 41.7% (10 infected out of 24), while the least infected were Arius gigas and Pomadasys jubelini with prevalence of 3.8% and 1.4%, respectively. No infection was recorded in Elops lacerta, Gobius sp., Lutjanus agennes, L. goreensis, Argyrosomus regius, Sphyraena guachancho, S. sphyraena, Cynoglossus senegalensis, Sarotherodon melanotheron, Tilapia guineensis, Liza falcipinnis, Mugil cephalus, and M. curema. The nematode parasites, Capillaria zederi, and Aplectana hamatospicula had the highest prevalence of 33.3% in D. margarita. Laurotravassoxyuris sp. also had the same prevalence in Trichiurus lepturus. Goezia sigalasi had the second highest prevalence of 12.5% in P. (Fonticulus) elongatus which had the highest number examined, due to its high dominance in the water. 1. Introduction Roundworms called nematodes are the most common parasites found in marine fishes [1]. Potentially all freshwater and brackish water fish may be affected, with heavier infections in predatory fish, particularly in species also utilizing fish as intermediate or transient hosts [2]. Forty (40) species of adult nematodes, representatives of families from fish in Africa, have been reported [3]. The majority occur in the alimentary system and only few enter tissues or inner cavities (Philometridae and Anguillicola, the Swimbladder) [2]. Copepods are the first intermediate host to Camallanidae, Cucullanidae, Philometridae, and Anguillicolidae. Life cycle studies of Procamallanus laevionchus and Paracamallanus cyathopharynx in Egypt revealed a development of the first three larval stages in Mesocyclops leuckarti [2]. Camallanidae give birth to first stage larvae, which are ingested by the copepods. Larvae in copepods, or other invertebrate hosts, will develop to fourth stage larvae and further into adult males and females when ingested by a suitable definitive host. Larvae ingested by “wrong” piscine hosts often survive as waiting stages (fourth stage larvae) in the gut or other tissues for a