Biomphalaria havanensis is a Natural First Intermediate Host for the Trematode Bolbophorus damnificus in Commercial Catfish Production in Mississippi

Abstract

The digenetic trematode Bolbophorus damnificus is a significant hindrance to the production of farm‐raised catfish in the southeastern USA. Severe infections with Bolbophorus damnificus can result in death, but the real damage lies in mild to moderate infections, which can go unnoticed by producers. Research has shown even mild infections can inhibit production to the point of operating at a net loss. The ramshorn snail Planorbella trivolvis is the first intermediate host for Bolbophorus damnificus and is prevalent in most commercial catfish ponds in the Southeast. Management practices aimed at controlling Bolbophorus damnificus infections primarily focus on reducing snail populations in ponds. Other aquatic snail species are also commonly associated with commercial catfish ponds, although little is known about their contributions to trematode infections in catfish. In the summer of 2014, 804 snails Biomphalaria havanensis (synonym: Biomphalaria obstructa) were collected from a single commercial catfish pond and screened for trematode infections. Seven of these snails (0.81%) were actively releasing cercariae identified molecularly as Bolbophorus damnificus. These cercariae were subsequently used in infectivity trials with Channel Catfish Ictalurus punctatus fingerlings (5–8 cm). Seven days postchallenge, fish were examined histologically for the presence of metacercariae, which were present in 13 of 15 (86.67%) surviving fish. This is the first report of naturally occurring infections of Bolbophorus damnificus in another snail species.

Encapsulation of Bolbophorus damnificus (Digenea: Bolbophoridae) Metacercariae in Juvenile Channel Catfish, Ictalurus punctatus, Is Linked to Delayed‐onset Mortality

“…A magnetic stir bar was added to the flask, and cercariae were gently stirred. While stirring, 10 aliquots of 100 μL were collected and placed as separate droplets on a plastic petri dish, similar to the methods used in previous studies (Yost ; Griffin et al , ; Rosser et al ; Alberson et al ). Cercariae in each droplet were counted using a Nikon SMZ‐U stereoscopic microscope (Nikon Instruments, Melville, NY, USA).…”

“…Bolbophorus damnificus (Digenea: Bolbophoridae) sequentially infects the American white pelican, Pelecanus erythrorhynchos ; the planorbid snails, Planorbella trivolvis and Biomphalaria havanensis ; and multiple fish hosts including channel and hybrid, I. punctatus × Ictalurus furcatus , catfish (Overstreet et al ; Griffin et al ; Rosser et al ). In US catfish aquaculture, outbreaks of B. damnificus have been linked to mortality, poor production efficiency, and increased incidence of bacterial infections (Wise et al ).…”

Fossil freshwater gastropods from northern Mexico – A case of a “silent” local extirpation, with the description of a new species

“…The single specimen was found in superficial sediments of the Juan Guerra Spring, Viesca. Both species were considered for a long time as different species (DeJong et al, 2001;Thompson, 2011) but recent molecular studies show that B. obstructa (as well as B. tamascalensis Rangel-Ruiz from Oaxaca, Mexico) is a junior synonym of B. havanensis (Aguiar-Silva et al, 2014;Rosser et al, 2016).…”

Assessment of Bolbophorus damnificus prevalence and cercariae shedding in Planorbella trivolvis populations from catfish aquaculture ponds in Mississippi, USA

“…Pond‐raised ictalurid catfish culture is the largest sector of the US aquaculture industry, accounting for >$360 million in sales during 2018 (USDA, 2018). The aggregation of farms and density of catfish within aquaculture ponds have provided ideal foraging grounds for many piscivorous birds, such as the American white pelican Pelecanus erythrorhynchos , great blue heron Ardea herodias , great egret Ardea alba and double‐crested cormorant Phalacrocorax auritus , creating an excellent environment for the successful transmission of trematode parasites (Alberson et al, 2017; Glahn & King, 2004; Griffin et al, 2012; Kudlai, Kostadinova, Pulis, & Tkach, 2015; Levy et al, 2002; Rosser et al, 2016a,b, 2017; Yost, Pote, Wise, Dorr, & Richardson, 2009). Since the late 1990's, Bolbophorus spp.…”