THE PREVALENCE OF HELMINTHOFAUNA AND FECUNDITY STUDIES IN WEST AFRICAN LUNGFISH, Protepterus annectens OWEN, 1839 (DIPTERIFORMES: LEPIDOSERINIDAE) IN RIVER ANAMBRA, NIGERIA
Ilozumba P.C.O. and Ezeife O.C.
Department of Zoology, Nnamdi Azikiwe University, P.M.B. 5025, Awka, Anambra State, Nigeria.
Keywords: Protopterus annectens, River Anambra, Heterorchis protopteri, fecundity, spawning.
Published in Volume 7
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Abstract:
An investigation was conducted on the helminthofauna and some aspects of reproductive biology of
the West African lungfish, Protopterus annectens in River Anambra, Nigeria, between May and July,
2008. The sample comprised forty two fishes purchased from fishermen and fish mongers at Otuocha
fish market, a major fish landing location in the Anambra River Basin. The sex composition of the
sample which was 1:41 (male: female) is thought to reflect a preponderance of female fish in the
natural population of P. annectens in the river system. Heterorchis protopteri, a digenean, was the
only helminth parasite recovered, infesting 6 (six) out of the 42 fish.33 worms were recovered, giving
a prevalence of 14.29 %, mean intensity of infection of 5.5 and mean abundance of 0.8 for the parasite
in the fish population. The infection parameters increased with size of fish (weight and length). No
parasite was recovered from the lone male fish examined, and this could be attributed to sample size.
H. protopteri is reported from P. annectens in Nigeria for the first time. All the female fish examined
were gravid while the lone male fish had ripe testes which indicate that P.annectens spawns in the
river system in the wet season. Fecundity of the species was estimated to be about 1423 eggs per
female and P. annectens is categorized as a mesofecund species. It is suggested that some form of
regulation of cropping of P. annectens in the river system should be put in place pending a clearer
understanding of its ecology, in order to reduce the chances of harming the recovery capacity of the
species.