Hematodinium perezi infections in adult arid juvenile blue crabs Callinectes sapidus from coastal bays of Maryland and Virginia, USA

Abstract

In coastal bays of Maryland and Virginia, USA, adult and juvenile blue crabs Callinectes sapidus were severely infected with the parasitic dinoflagellate I-lematodinium perezi. Dinoflagellates were observed in the hemocoel of all infected crabs; associated histopathological changes were evident in some tissues. Dinoflagellates could be observed with an inverted microscope through the 5th pleopod of heavily infected juvenile crabs (5 to 29 mm) without invasion. This note documents a high prevalence of H. perezj infections in juvenile blue crabs from coastal bays in Maryland and Virginia. The seasonal infection prevalence cycle reported by previous authors is consistent with observations made during this study.

Co-infection by a yeast-like organism in Hematodinium-infected European edible crabs Cancer pagurus and velvet swimming crabs Necora puber from the English Channel

“…infections in numerous other crustacean species worldwide (Newman & Johnson 1975, Maclean & Ruddell 1978, Meyers et al 1987, Field et al 1992, Hudson & Lester 1994, Hudson & Shields 1994, Messick 1994, Taylor & Khan 1995, Wilhelm & Mialhe 1996. Since no crabs were observed to be infected only by the yeast-like organism, we suggest that it is an opportunistic pathogen, possibly exploiting the weakened immune system of the host crab, a feature known to accompany Hematodinium sp.…”

“…A similar parasite, also described infecting N. puber, is suspected of causing a major collapse of a once lucrative fishery in French coastal waters (Wilhelm & Mialhe 1996). Hematodinium-like organisms have also been reported from several other commercially important crustacean species from around the world (Newman & Johnson 1975, Maclean & Ruddell 1978, Meyers et al 1987, Field et al 1992, Hudson & Lester 1994, Hudson & Shields 1994, Messick 1994, Taylor & Khan 1995, Wilhelm & Mialhe 1996.…”

“…This host non-recognition of Hematodinium sp. infections is likely to play a key role in the pathogenesis of this disease, and may help to explain the abundance and rapid proliferation of Hematodinium cells within the haemolymph of infected hosts (Newman & Johnson 1975, Maclean & Ruddell 1978, Meyers et al 1987, Field et al 1992, Hudson & Lester 1994, Hudson & Shields 1994, Messick 1994, Taylor & Khan 1995, Wilhelm & Mialhe 1996, Stentiford et al 2002.…”

Disease will limit future food supply from the global crustacean fishery and aquaculture sectors

“…C. crangon bacilliform virus in Crangonid shrimps; Stentiford et al, 2004, and Hematodinium sp. infection of blue crabs; Messick, 1994) without causing long term decline of the host population. Diseases of wild crustaceans may therefore hold vital clues for mitigating the negative impact of pathogens in cultured crustaceans.…”

Nucleotide sequence determination of the partial SSU rDNA gene and ITS1 region of Hematodinium cf. perezi and Hematodinium-like dinoflagellates

“…H. cf. perezi has also been recorded from Callinectes sapidus, a decapod of commercial importance (Newman & Johnson 1975, Messick 1994. Hematodiniurn-like dinoflagellates have had severe effects on Chionoecetes bairdi, C. opilio and Nephrops norvegicus, all decapods of commercial importance (Meyers et al 1987, Field et al 1992).…”