Aeromonas hydrophila causes ‘black disease' in fairy shrimps (Anostraca; Crustacea)

Abstract

A total of 51 bacterial strains were isolated from fairy shrimps [Branchipus schaefferi (Fisher), Chirocephalus diaphanus (Prévost) and Streptocephalus torvicornis (Waga)] showing signs of 'black disease'. The fairy shrimps showed black nodules on the thoracic appendages, the cercopods, the antennae and sometimes at the back of the head. The infection sites on the thoracic appendages were restricted to the proximal parts of the endopodite, the exopodite and endite I. In order to check Koch's postulates, pure bacterial cultures were administered to healthy fairy shrimps. One bacterial pathogen was identified as Aeromonas hydrophila using BIOLOG and the genotypic fingerprinting technique AFLP.

Clinical observations of black disease in fairy shrimps, Streptocephalus sirindhornae and Branchinella thailandensis, from Thailand and pathogen verification

“…black disease, is a major factor limiting their cultivation. The appearance of the disease found on fairy shrimp in Thailand is similar to that found in other countries including Spain, Algeria, Germany, America, Belgium (Dierckens, Vandenberghe, Beladjal, Huys, Mertens & Swings 1998) and Japan (Nambu, Tanaka & Nambu 2007). The disease is considered to be a cause of mortality in fairy shrimp and also has an adverse effect on commercial cultivation.…”

“…were used as food. The fairy shrimp were then exposed to bacterial strains for 5 days (Dierckens et al. 1998) and their behaviour was observed daily.…”

The Family Aeromonadaceae

“…Also in various animal species, Aeromonas has been associated with a range of infections. Most notably, such cases have been frequently reported in poikilothermic animals including amphibians, reptiles, fish, and shrimps (Marcus 1971(Marcus , 1981Shotts et al 1972;Brackee et al 1992;Burns et al 1996;Gosling 1996;Schilliger 1997;Dierckens et al 1998). One of the first animal infections attributed to Aeromonas was the so-called redleg disease in frogs (Sanarelli 1891).…”

Bath efficacy of sodium hypochlorite, oxytetracycline dihydrate and chloramphenicol against bacterial black disease in fairy shrimpBranchinella thailandensis

“…A recent study showed that black disease, caused by Aeromonas spp., leads to mortality in fairy shrimp. The disease is recognized as having a severe effect on productivity (Dierckens, Vandenberghe, Beladjal, Huys, Mertens & Swings 1998;Saejung, Hatai, Wada, Kurata & Sanoamuang 2011). To overcome black disease, several organic salts, chemical disinfectants and antibiotics were tested to determined levels of pathogen inhibition in vitro.…”