Prevalence of fish Parasites IN Bagrus bayad and Protopterus annectens from Upper River Benue in Mutum Biu, Taraba State, Nigeria

The prevalence of fish parasites in Bagrus bayad and Protopterus annectens from Upper River Benue in Mutum Biu, Taraba State, Nigeria was carried out using standard parasitological method. The objectives of this study were to investigate the parasite species spectrum, prevalence of each parasites species, overall prevalence, prevalence of parasite infection in relation to the size and sexes of Bagrus bayad and Protopterus annectens and the infection induced by parasites on/in their body parts, with the view of providing relevant information that can be used in combating the rate of economic losses that could be experienced as a result of parasitic infestations. 4 parasite taxa comprising of Twelve (12) parasite species (Trichodina spp., Henneguya spp. Cryptobia iubilans, Diphillobothrium latum, Hymenolepis nanna and Bothriocephalus aengypticus, Capillaria philipinensis, Caenorhabditis briggsae, Camallanus spp., Eustrongylides spp., Contracaecum spp. and Clinostomum spp. were recovered from the samples of fish species used during the study period. Twelve (12) of the parasite species were recovered from Bagrus bayad while seven (7) were recovered from Protopterus annectens. Among the body parts of Bagrus bayad, while intestine had the highest percentage parasite load (56.37%), highest percentage parasite load (46.22%) in Protopterus annectens was recorded for stomach (46.22%). Out of the 400 fish samples comprising of 200 each of Bagrus bayad and Protopterus annectens, 234 (58.50%) comprising of 99 (49.50%) and 135 (67.50%) samples each of Bagrus bayad and Protopterus annectens were infested with 369 and 119 parasites, respectively. However, there was no significant difference in the prevalence of infection and parasite load between the fish species, respectively (P>0.05). Generally, larger sized samples of Bagrus bayad and Protopterus annectens had higher percentage of infection compared to the smaller sized of both samples although, the prevalence of infection in relation to sizes of both fish species was not statistically significant (P>0.05). Female Bagrus bayad and Protopterus annectens had higher prevalence of infection (21.61%) and (16.63%) than the males (6.37%) and (6.24%), respectively. There was no significant difference in the prevalence of infection in relation to the sexes of both fish species (P>0.05). Epidermal necrosis of the caudal fin and skin, thickened intestinal epithelium at the site of parasite attachment, hyperplasia of the intestinal villi and lamina propria, hyperplasia of infected gills at the secondary lamellae, ulceration of the stomach, abdominal distention, eroded and flattened intestinal folds and lymphocytic infiltration of intestinal mucosa and edema of the lamina propria of the intestine were observed with the infected samples of B. bayad. The infected samples of P. annectens exhibited epidermal necrosis of the skin.