Environmental and physiological conditions affecting Tetrahymena sp. infection in guppies, Poecilia reticulata Peters

Abstract

Parasitic infections caused by Tetrahymena sp. constitute a serious problem in guppies, Poecilia reticulata. Tetrahymena was isolated from skin lesions of naturally infected guppies in a commercial aquaculture farm, cultured in vitro and used in subsequent experimental infections. In addition to guppies, angelfish, Pterophyllum scalare, platyfish, Xiphophorus maculates, and neontetra, Paracheirodon innesi, were susceptible, whereas tilapia (Oreochromis niloticus xO. aureus) was resistant. The ciliate had a high affinity for dead fish. Skin abrasion did not affect the infection, but fish with gas bubble disease exhibited a significantly higher infection than non-affected fish. Infection was significantly higher when fish were exposed to high levels of ammonia, high organic load and low water temperatures. Under shipment conditions, infection was significantly elevated. Full recovery was achieved at a low fish density. Results suggest that poor environmental and physiological conditions enhance infection with Tetrahymena sp.

Recommendations for control of pathogens and infectious diseases in fish research facilities

“…Comprehensive reviews and books on diseases in captive fishes and reports on specific diseases and protocols for laboratory fishes can be found elsewhere (Woo, 2006; Stoskopf et al, 1993; Casebolt et al 1998; Hoffman, 1999; Woo and Bruno, 1999; Noga, 2000; Ostrander, 2000; Dykstra et al, 2001; Astrofsky et al, 2002a,\b; Lee and O’Bryen, 2003; Matthews, 2004; Nickum et al, 2004; Batt et al, 2005; Pimenta-Leibowitz et al, 2005; Scarfe et al, 2006; Ferguson, 2006; Kent and Fournie, 2007). Our intent here is to present general recommendations and strategies for researchers, fish technicians, and veterinarians for controlling pathogens of fishes in research situations.…”

Protective immunization against Tetrahymena sp. infection in guppies (Poecilia reticulata)

“…Pimenta-Leibowitz et al [4] reported that poor environmental and adverse physiological conditions predispose the fish to infections with Tetrahymena sp.…”

“…The genus Tetrahymena, comprising ciliated protozoa (Ciliophora) of the order Hymenostomatida, has been reported from a range of fish species, including the Atlantic salmon Salmo salar, the zebrafish Danio rerio, pristella (Pristella maxillaries), neontetra (Paracheirodon innesi), cherry barb (Puntius titteya Diraniyagala), angelfish (Pterophyllum scalare) and platyfish (Xiphophorus maculatus) [1][2][3][4]. However, infections are most commonly reported from guppies, hence the names Tet disease and ''guppy killer parasite'' [4,5].…”

Treatment development for systemicTetrahymenasp. infection in guppies,Poecilia reticulataPeters

“…Internal infection caused by Tetrahymena (Ciliophora, Hymenostomatida) constitutes a serious problem for ornamental fish farms worldwide (Imai, Tsurimaki, Goto, Wakita & Hatai 2000; Pimenta Leibowitz, Ariav & Zilberg 2005). The genus Tetrahymena includes free‐living, generally saprozoic ciliates that feed on particulate food, including bacteria (Lom 1995).…”

“…Many species are facultative parasites whereas others may be obligate (Lom 1995). The parasite has been reported from a range of fish species but infections are most commonly reported in guppies, Poecilia reticulata Peters (Ferguson, Hicks, Lynn, Ostland & Bailey 1987; Astrofsky, Schech, Sheppard, Obenschain, Chin, Kacergis, Laver, Bartholomew & Fox 2002; Pimenta Leibowitz et al. 2005).…”