Evaluation of Parasitofauna of Four Economically Important Fish Species (Synodontis Budgetti, Chrysichthys Nigrodigitatus, Bagrus Docmac and Heterobranchus Bidorsalis) From River Okpokwu, Apa, Nigeria
Authors: S. Omeji , O.D. Kolndadacha , M.O. Adadu 
Published: August 2022

The parasitic fauna of four economically important fish species comprising of Synodontis budgetti, Chrysichthys nigrodigitatus, Bagrus docmac and Heterobranchus bidorsalis from River Okpokwu, Apa, Nigeria, was investigated. A total of 161 fish samples comprising of 57 S. budgetti, 48 C. nigrodigitatus, 24 B. docmac and 32 H. bidorsalis were randomly purchased and subjected to parasitological examination. The overall parasite prevalence of all the fish species was 36.60% out of which S. budgetti, C. nigrodigitatus, B. docmac and H. bidorsalis accounted for 14.30%, 11.20%, 1.90% and 9.30%, respectively. However, the prevalence of infection by each fish species were 40.40%, 37.50%, 12.50% and 46.90% for S. budgetti, C. nigrodigitatus, B. docmac and H. bidorsalis, respectively. There was no significant difference in parasite prevalence for fish species (p>0.05) though, S. budgetti had the highest prevalence of infection (14.70%) with B. docmac recording the least (1.90%). Also, while the highest prevalence of infection was recorded for nematode (17.40%), the least (3.70%) each was recorded for trematode and copepode, respectively. Of the parasitic taxa, nematode was the most abundant (56.50%) and had the highest prevalence (17.40%). The parasites recovered from the fish species belonged to a species of acanthocephala (Neoechinorhynchus rutili), copepode (Argulus africanus.) trematode (Clinostomum complanatum), 2 species of cestode (Ligula intestinalis and Diphillobothrium latum) and 4 species of nematode (Capillaria philippinensis, Eustrongylides tubifex, Camallanus polypteri and Procamallanus laevionchus). Out of the total number (292) of parasites recovered from the infested body parts of the fish, intestine had the highest percentage parasite load (62.30%) and prevalence (29.80) while the gill had the least 16(5.50%) parasite load and prevalence of 3.10. Generally, the prevalence of parasites (43.00%), percentage parasite recovered (56.50%), mean abundance (2.60) and mean intensity (5.90) were higher for the female fish samples compared to the males with the prevalence of parasites, percentage parasite recovered, mean abundance and mean intensity of (32.00%), (43.50%), (1.30) and (4.10), respectively. However, there was no significant difference (p>0.05) by sex in the prevalence of parasites of all the fish species. The size class related prevalence showed an increase in parasitic infections (24.60%) and (20.80%) in S. budgetti and C. nigrodigitatus) in the length groups of 13.00 to 15.90cm and 19.00 to 22.90cm while the least (5.30%) and (6.30%) were recorded for S. budgetti and C. nigrodigitatus in the length groups of 10.00 to 12.90cm and 15.00 to 18.90cm, respectively. However, while the highest prevalence (8.30%) and (21.90%) were recorded for smaller samples of B. docmac and H. bidorsalis in the length groups of 10.00 to 20.90cm and 13.00 – 21.90cm, the least (4.20%) and (3.10%) were recorded in length groups of 41.00 to 50.90cm and 39.00 – 54.90cm for bigger samples of B. docmac and H. bidorsalis, respectively.

Keywords: Parasitofauna, River Okpokwu, Prevalence, Nematode, Sex