Farm‐Level Economic Impacts of Bolbophorus Infections of Channel Catfish

Abstract

The prevalence of infections by trematodes Bolbophorus sp. in populations of pond‐raised channel catfish Ictalurus punctatus was determined by sampling 64 ponds on a farm in northwestern Mississippi. Of the 40 food fish ponds sampled, 23 (58%) contained trematode‐infected fish; 7 pond populations were categorized as having light infections (1–33% infection rates), 5 as having moderate infections (34–66% infection rates), and 11 as having severe infections (≥67% infection rates). Only 3 of the 24 fingerling ponds contained fish infected with Bolbophorus trematodes, and the infection rates were light. Feed consumption and estimated fish production in food fish ponds differed significantly among the four categories of within‐population infection rate, and feed consumption and fish production decreased as infection rates increased. Relative to the production in uninfected populations, estimated fish production was reduced by 14, 35, and 40% in populations with light, moderate, and severe infections, respectively. Estimated catfish receipts and actual feed costs were used in a generalized enterprise budget format to calculate income above variable costs and net returns for each infection‐rate category. The estimated net return to land for uninfected food fish populations was US$1,526/ha. Lower fish production in infected populations resulted in decreased incomes. The net return to land was $592/ha for the light‐infection‐rate category, a 61% reduction from that achieved in uninfected populations. Production receipts from food fish ponds in the moderate‐ and severe‐infection‐rate categories did not cover the costs of production, and the net returns to land were −$781/ha for moderately infected populations and −$1,123/ha for severely infected populations. This study shows that trematode infections reduce fish production and farm economic returns and that the impacts increase as infection rates increase. However, even light and moderate infections—which may go unnoticed by farmers—can seriously affect farm profitability.

Clinostomum album n. sp. and Clinostomum marginatum (Rudolphi, 1819), parasites of the great egret Ardea alba L. from Mississippi, USA

“…Clinostomum marginatum has been reported from farm-raised catfish in the southeastern United States, where infections may lead to unmarketable fish at processing. However, C. marginatum infections are rare and generally of little consequence to catfish aquaculture compared to other more damaging digeneans (Lorio, 1989;Wise et al, 2008;Griffin et al, 2012).…”

Direct Economic Impact of Fish Diseases on the East Mississippi Catfish Industry

“…; Wui and Engle ; Wise et al. ; Cunningham et al. ; W. B. Hemstreet, Auburn University, AL Fish Farming Center, Greensboro, unpublished data) efforts to quantify the economic impact of catfish diseases in the southeastern USA, especially in east MS.…”

Copper Sulfate Pretreatment for Snail Control Reduces Channel Catfish Fry Survival

“…The digenetic trematode Bolbophorus damnificus is a serious problem in farm‐raised catfish in the southeastern United States (Wise et al. , ). The parasite has a complex life cycle, sequentially involving the American white pelican Pelecanus erythrorhynchos , the planorbid snails Planorbella trivolvis and Biomphalaria havanensis , and Channel Catfish Ictalurus punctatus or hybrid catfish (♀ Channel Catfish × ♂ Blue Catfish I. furcatus ; Levy et al.…”