Helminth Parasites of Gobies from Two Creeklets of the New Calabar River, Rivers State, Nigeria

Aim: An animal species either serves as a definitive, a paratenic or an intermediate host to helminth parasites which may be species or site specific. This study was undertaken to investigate the intestinal helminth parasites of gobies (Bostrychus africanus and Periophthalmus papilio) collected from two creeklets of the New Calabar River.

Study Design: Fifteen samples of each species were collected (from two stations fortnightly) measured and weighed. All fish was dissected and intestinal parasites were collected, identified and counted. Physico-chemical parameters (temperature, dissolved oxygen (DO) and salinity) of the study areas were also measured in dry and rainy seasons. A total of 240 fish samples were examined of B. africanus (Standard length (SL) of 3 - 12 cm, weight of 30 - 36.1g), and P. papilio (SL of 5.9 - 15 cm, weight of 4 - 28.2g).

Study Period: Study was between October 2016 and May 2017.

Results: A total of three hundred and eigthy nine (389) nematodes (Ascaridida) were isolated from 25.4% of the sampled fish. Bostrychus africanus had higher percentage prevalence and mean intensity (91.6 % and 23 in station 1, 21.8 % and 20.5 in station 2). P. papilio had a lower percentage prevalence of 0.7 % and mean intensity of 4 in station 1 and 5.7 %, 8 in station 2. The nematodes were recovered from the stomach, small and large intestine of infected fish. The total lengths of infected and non-infected B. africanus from station 1 were different at P < 0.05 revealing that size affects the prevalence of parasites.

Conclusion: There was no significant difference in the relative condition factor (Kn) of infected and non-infected B. africanus and P. papilio from both stations indicating that the parasite did not affect the condition of the fish. Sex appeared to play a role in parasite prevalence in B. africanus. B. africanus and P. papilio from Rumuolumeni and Bakana creeks in the Niger Delta were infected with Ascaridida nematodes in the GIT. The prevalence and intensity of infection was higher in B. africanus and at Rumuolumeni.