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Interactions between Cage‐Cultured Hybrid Tilapia and a Marine Monogenean, Neobenedenia melleni , in Jamaica
Author(s) -
Robinson Ralph D.,
O'Connor Nicola P. G.,
Steele R. Dunbar
Publication year - 2008
Publication title -
north american journal of aquaculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 41
eISSN - 1548-8454
pISSN - 1522-2055
DOI - 10.1577/a06-037.1
Subject(s) - oreochromis mossambicus , tilapia , biology , parasite hosting , cage , oreochromis , veterinary medicine , mucus , sparidae , fishery , fish <actinopterygii> , zoology , ecology , medicine , mathematics , combinatorics , world wide web , computer science
Interactions between caged hybrid tilapia Oreochromis aureus × O. mossambicus and Neobenedenia melleni , a marine monogenean, were examined in coastal waters off Jamaica. Tilapia fingerlings were maintained in mesh cages (30 fish per 0.75 m 3 ) from September 2004 to August 2005. Infection prevalence and mean intensity were recorded every 4–5 weeks after freshwater dipping of infected fish and physical dislodgement of the parasites. Surviving fish were returned to a seawater cage, allowing reinfection with N. melleni . The prevalence of infection initially peaked (89.3%; n = 28) at 12 weeks' exposure and fell to 14.3% ( n = 7) in week 20; by week 29, all 5 of the fish that had survived were infected. The mean intensity of infection followed a similar profile, peaking at 12 weeks' exposure, dipping in week 20, and rising thereafter (Pearson r = 0.841; P = 0.002). Differential blood cell counts showed no significant differences between infected and uninfected fish, nor was there evidence of a humoral response in a radial diffusion assay. However, mucus from caged fish that had been exposed for 9–15 weeks killed approximately 100% of the N. melleni in 3 h. Maricultured red tilapia are highly susceptible to infection with N. melleni and appear to develop temporary, largely innate resistance to the parasite.