Description
Caullery & Mesnil, 1899 With characters of the phylum. TEM bLM Q 9 Spores with a hinged operculum externally covering an anterior orifice in the spore wall ................ ...... .... Family Haplosporidiidae .... . 1 Spores with a flap of wall material which internally covers the anterior spore wall orifice .... .. .. .............. .... Family Urosporidiidae ....... 2 1. Spores with tubules, filaments , or ribbons of material around the external surface of the spore wall and not organized into pronounced extensions visible in the light microscope ....... ................. Haplosporidium 1'. Spores with filaments or tubules supporting two to four prominent extensions visible in the light microscope ............ .... .. .. Minchinia 2. With characters of the Family .Urosporidium In an earlier review of the phylum (Perkins, 1990), I did not recognize the family Urosporidiidae, including Urosporidium spp . in the family Haplosporidiidae. This may have been an error since 1) generic distinctions are being made between Haplosporidium and Minchinia on the basis of the rather tenuous difference as to whether the epispore cytoplasm exhibits prominent extensions , whereas 2) the wall structure of Urosporidium is fundamentally different from species of the other two genera. Once knowledge of nucleic acid base sequences, as for example, small subunit ribosomal RNA sequences, are made available, the choice as to whether to accept a second family may become less arbitrary . There has been much debate in the literature concerning the distinctions between the genera Haplosporidium and Minchinia as well as whether the genus Minchinia should be recognized (Sprague , 1963, 1970, ) 978, 1982; Perkins , 1990; McGovern and Burreson, 1990; Lauckner , 1983; Ormieres, 1980). Much of the debate is due to the lack of ultrastructural observations and inadequacies with the original type species descriptions, all resulting in a taxonomic "nightmare" . Even though 12 different species have been examined in the electron microscope , there continues to be uncertainty. Thus the taxonomic scheme presented herein w iII undoubtedly be subject to continued debate . The original description of the type species for Minchinia, M. chitonis (Lankester , 1885) Labbe , 1896, presents complications in that the description by Labbe (1896) involved observations of the spores of a haplosporidian and other stages of a coccidian. This followed the original brief notation of Lankester (1885) in which he drew a picture of a haplosporidian spore with two prominent extensions and briefly wrote that it was a new sporozoan species which he called Klossia chitonis. He stated that it was from a chiton . This problem of two species being involved was noted by Debaisieux (1920), who renamed the protist with haplosporidian spores, Haplosporidium chitonis , and the coccidian protist, Pseudoklossia chitonis. This name change held until Sprague (1963) re-established the
Type species
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Caullery & Mesnil, 1899 With characters of the phylum. TEM bLM Q 9 Spores with a hinged operculum externally covering an anterior orifice in the spore wall ................ ...... .... Family Haplosporidiidae .... . 1 Spores with a flap of wall material which internally covers the anterior spore wall orifice .... .. .. .............. .... Family Urosporidiidae ....... 2 1. Spores with tubules, filaments , or ribbons of material around the external surface of the spore wall and not organized into pronounced extensions visible in the light microscope ....... ................. Haplosporidium 1'. Spores with filaments or tubules supporting two to four prominent extensions visible in the light microscope ............ .... .. .. Minchinia 2. With characters of the Family .Urosporidium In an earlier review of the phylum (Perkins, 1990), I did not recognize the family Urosporidiidae, including Urosporidium spp . in the family Haplosporidiidae. This may have been an error since 1) generic distinctions are being made between Haplosporidium and Minchinia on the basis of the rather tenuous difference as to whether the epispore cytoplasm exhibits prominent extensions , whereas 2) the wall structure of Urosporidium is fundamentally different from species of the other two genera. Once knowledge of nucleic acid base sequences, as for example, small subunit ribosomal RNA sequences, are made available, the choice as to whether to accept a second family may become less arbitrary . There has been much debate in the literature concerning the distinctions between the genera Haplosporidium and Minchinia as well as whether the genus Minchinia should be recognized (Sprague , 1963, 1970, ) 978, 1982; Perkins , 1990; McGovern and Burreson, 1990; Lauckner , 1983; Ormieres, 1980). Much of the debate is due to the lack of ultrastructural observations and inadequacies with the original type species descriptions, all resulting in a taxonomic "nightmare" . Even though 12 different species have been examined in the electron microscope , there continues to be uncertainty. Thus the taxonomic scheme presented herein w iII undoubtedly be subject to continued debate . The original description of the type species for Minchinia, M. chitonis (Lankester , 1885) Labbe , 1896, presents complications in that the description by Labbe (1896) involved observations of the spores of a haplosporidian and other stages of a coccidian. This followed the original brief notation of Lankester (1885) in which he drew a picture of a haplosporidian spore with two prominent extensions and briefly wrote that it was a new sporozoan species which he called Klossia chitonis. He stated that it was from a chiton . This problem of two species being involved was noted by Debaisieux (1920), who renamed the protist with haplosporidian spores, Haplosporidium chitonis , and the coccidian protist, Pseudoklossia chitonis. This name change held until Sprague (1963) re-established the