Enterospora sp., an intranuclear microsporidian infection of hermit crab Eupagurus bernhardus

Abstract

Recent work at our laboratory has led to the discovery of a new genus of microsporidian parasite residing in the family Enterocytozoonidae. The type species of this new genus, Enterospora canceri, is an intranuclear parasite infecting the hepatopancreatocytes of the decapod crustacean Cancer pagurus. Here we provide the second description of a parasite within the genus Enterospora, this time infecting the hermit crab Eupagurus bernhardus from UK waters. The pathological manifestation and ultrastructural features of the hermit crab parasite are very similar to those described for E. canceri. Further taxonomic comparisons based upon ultrastructural and molecular affinities of Enterospora are now required to define firmer links between this new genus within the Enterocytozoonidae and all other microsporidian families. The opportunistic nature of the discovery of a second intranuclear microsporidian within the Crustacea suggests that their presence may be more common than in higher animal groups.KEY WORDS: Eupagurus bernhardus · Enterocytozoon · Enterocytozoonidae · Enterospora · Epithelium · Hermit crab · Hepatopancreas · Nucleospora · Intranuclear · Nucleus · CrustaceaResale or republication not permitted without written consent of the publisher

Enterospora canceri n. gen., n. sp., intranuclear within the hepatopancreatocytes of the European edible crab Cancer pagurus

“…Further work should attempt to gather appropriate infected material from C. pagurus and to investigate the taxonomy of other hepatopancreatic microsporidians from crustaceans. That a currently undescribed species, with developmental features of the Enterocytozoonidae and infecting the nucleoplasm of hepatopancreatic cells has recently been discovered from the hermit crab Eupagurus bernhardus (Stentiford & Bateman 2007, this issue) supports this view.…”

“…Further work should attempt to gather appropriate infected material from C. pagurus and to investigate the taxonomy of other hepatopancreatic microsporidians from crustaceans. That a currently undescribed species, with developmental features of the Enterocytozoonidae and infecting the nucleoplasm of hepatopancreatic cells has recently been discovered from the hermit crab Eupagurus bernhardus (Stentiford & Bateman 2007, this issue) supports this view.The significance of this parasite as a mortality driver in Cancer pagurus stocks has not been assessed. While the apparent prevalence of infection in the Weymouth Bay stock appears to be low, no information is available on infection prevalence in other European stocks or for juvenile crabs that fall below the legal minimum landing size.…”

Decay of the glycolytic pathway and adaptation to intranuclear parasitism within Enterocytozoonidae microsporidia

“…In fact, some of the aquatic host‐infecting microsporidian species belonging to the Enterocytozoonidae family inhabit the host nucleus rather than the cytoplasm. These species include Enterospora canceri , Enterospora nucleophila , several members of the genus Nucelospora and Desmozoon lepeophtherii (=Paranucleospora theridion) (Chilmonczyk et al ., ; Hedrick et al ., ; Lom and Dykova, ; Stentiford and Bateman, ; Stentiford et al ., ; Freeman and Sommerville, ; Nylund et al ., ; Freeman et al ., ). These species have no access to the host mitochondria so cannot use this strategy to maximize ATP uptake.…”

Paranucleospora theridion n. gen., n. sp. (Microsporidia, Enterocytozoonidae) with a Life Cycle in the Salmon Louse (Lepeophtheirus salmonis, Copepoda) and Atlantic Salmon (Salmo salar)

“…A Nucleospora ‐like intranuclear microsporidian was also detected in inflammatory cells in X‐cell pseudotumours in the English sole, Pleuronectes vetulus (Gresoviac et al 2007). Intranuclear development has been observed in Enterospora spp., microsporidians infecting the hepatopancreatocytes of marine decapod crustaceans (Stentiford and Bateman 2007; Stentiford et al 2007). Also, a Nucleospora ‐related microsporidian has been detected in Lepeophtheirus salmonis , a copepod ectoparasite of salmonid fish (Freeman, Bell, and Sommerville 2003).…”