Distribution of Pirhemocyton Chatton & Blanc and other, Possibly Related, Infections of Poikilotherms

Abstract

SYNOPSIS. Data for host and geographic distribution are listed for Pirhemocyton and for apparently similar infections of poikilothermic vertebrates. The list was compiled from published accounts of Pirhemocyton, Toddia, Cytamoeba, Bertarellia, Piscine erythrocytic necrosis, Immanoplasma, Haematractidium, Sauroplasma, Sauromella, Serpentoplasma, Tunetella, Haemohormidium and unnamed infections. New records are included for Pirhemocyton and Haematractidium. The probability that some may be viruses and not protozoa is discussed; Haematractidium is shown by electron microscopy to be a eukaryote whereas Immanoplasma is not a eukaryote.

Potential environmental and host gender influences on prevalence of Haemogregarina platessae (Adeleorina: Haemogregarinidae) and suspected Haemohormidium terraenovae (incertae sedis) in Brazilian flounder from the Patos Lagoon Estuary, Southern Brazil

“…Since the parasite found in the current study comes from a flatfish, it has a loop-like structure between some nuclei as in So's (1972) illustrations, and it resembles Siddall et al 's (1994) light micrographs of H. terraenovae, it is logical to identify it provisionally as this organism. Its likeness to Haematractidium scombri Henry, 1910 is also noted (see Henry 1910, 1913c, Johnston 1975, MacLean 1980, Davies 1995. However, extracellular forms, like those seen in our material, were not recorded by any authors who previously reported H. terraenovae.…”

“…They are often irregularly round in shape, exhibit peripheral staining with Romanowsky dyes, and show evidence of intraerythrocytic division (Henry 1913b, Laird and Bullock 1969, So 1972, Davies 1980, Barta 1991. Khan (1980Khan ( , 1984 demonstrated transmission of Haemohormidium beckeri So, 1972 and similar infections between fishes by haematophagous leeches, believing the blood parasites to be piroplasms, but controversy has remained surrounding the taxonomy of the genus Haemohormidium and the equally enigmatic genus Haematractidium Henry, 1910(see Henry 1910, 1913c, Johnston 1975, MacLean 1980, Bodammer and MacLean, 1985, Davies 1995. This uncertainty was summarised by Siddall et al (1994) who concluded that Haemohormidium and Haematractidium are synonymous genera, with the former taking priority; moreover, the identity of these parasites was not established, but they were not considered apicomplexan.…”

Intraerythrocytic iridovirus in central bearded dragons (Pogona vitticeps)

“…27 Reptile EIVs have been reported in diverse squamate species. 18,36,37 Similarly in amphibians, Frog erythrocytic virus, which causes intraerythrocytic intracytoplasmic inclusions, is an iridovirus that does not belong to the genus Ranavirus. 5,10,32 Frog erythrocytic virus has been shown to measure 293-312 nm 32 ; this is larger than PvEIV, which measures 141-193 nm.…”

“…37 Within the family Agamidae, EIVs have been found in the Bibron's agama (Agama impalearis) 2 and the common agama (A. agama). 18,26 In some cases, erythrocytic inclusions have been associated with marked anemia, 17,26 but experimental infection has failed to reproduce anemia unless the lizards were maintained in a cold environment. 3 Many viral diseases of poikilothermic vertebrates are highly temperature dependent, including iridoviruses, and the current data does not differentiate among the relative roles of host and virus on temperature-dependence of disease.…”

Virus-associated papillomatous skin lesions in a giant guitarfish Rhynchobatus djiddensis: a case report

“…Although descriptions are not well documented and host records confused, small intracytoplasmic inclusions, attributed to viral erythrocytic necrosis (VEN), have been reported in stained blood smears of erythrocytes from the small-spotted catshark Scyliorhinus canicula (Johnston 1975) and the little skate Raja erinacea (Khan & Newman 1982). McAllister & Stoskopf (1993) describe sharks with low hematocrits, pale gills and organs, and hyperplastic hematopoietic tissues.…”