Variations in the spores of<i>Myxidium zealandicum</i>Hine, 1975 (Protozoa: Myxosporidea)

Hine, P. M.

doi:10.1080/00288330.1978.9515740

Cited by 15 publications

(4 citation statements)

References 6 publications

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“…Similarly, Hine (1978Hine ( , 1979 found an average in M. giardi ( = M . zealandicum) of 12 to 26 while the full range was 9 to 20 ridges on one shell valve.…”

Section: Discussionmentioning

confidence: 99%

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Ultrastructural aspects of Myxidium giardi (Myxozoa, Myxosporea), parasite of the European eel Anguilla Anguilla

Azevedo¹,

Lom²,

Corral³

1989

Dis. Aquat. Org.

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“…Similarly, Hine (1978Hine ( , 1979 found an average in M. giardi ( = M . zealandicum) of 12 to 26 while the full range was 9 to 20 ridges on one shell valve.…”

Section: Discussionmentioning

confidence: 99%

“…The spores were studied by Hine (1978) and Lo (1981) by scanning electron microscopy. The transmission electron microscope study by Hulbert et al (1977) left many questions of sporogony and pansporoblast formation unanswered and the very brief account of Lo (1981) concerns the principal structures of mature spores only.…”

Section: Introductionmentioning

confidence: 99%

Ultrastructural aspects of Myxidium giardi (Myxozoa, Myxosporea), parasite of the European eel Anguilla Anguilla

Azevedo¹,

Lom²,

Corral³

1989

Dis. Aquat. Org.

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“…However, many descriptions of Myxidium spp. infecting eels have subsequently been synonymized with M. giardi , as less emphasis was placed on details such as the site of infection [ 11 ] and M. giardi was considered to have an almost worldwide distribution [ 12 ]. Currently, it is not clear whether M. giardi is a widely distributed parasite infecting numerous species of eels, in multiple organs, or whether some infections represent other, morphologically similar, species of myxosporeans.…”

Section: Introductionmentioning

confidence: 99%

Studies of Myxidium giardi Cépède, 1906 infections in Icelandic eels identifies a genetically diverse clade of myxosporeans that represents the Paramyxidium n. g. (Myxosporea: Myxidiidae)

Freeman

Kristmundsson

2018

Parasites Vectors

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BackgroundThe myxosporean Myxidium giardi Cépède, 1906 was described infecting the kidney of the European eel, Anguilla anguilla (L.), having spindle-shaped myxospores and terminal sub-spherical polar capsules. Since then, numerous anguillid eels globally have been documented to have similar Myxidium infections. Many of these have been identified using the morphological features of myxospores or by the location of infection in the host, and some have been subsequently synonymised with M. giardi. Therefore, it is not clear whether M. giardi is a widely distributed parasite, infecting numerous species of eels, in multiple organs, or whether some infections represent other, morphologically similar but different species of myxosporeans. The aim of the present study was to assess the status of M. giardi infections in Icelandic eels, and related fish hosts in Malaysia and to use spore morphology and molecular techniques to evaluate the diversity of myxosporeans present.ResultsThe morphologies of the myxospores from Icelandic eels were very similar but the overall dimensions were significantly different from the various tissue locations. Myxospores from the kidney of the Malaysian tarpon, Megalops cyprinoides (Broussonet), were noticeably smaller. However, the SSU rDNA sequences from the different tissues locations in eels, were all very distinct, with percentage similarities ranging from 92.93% to as low as 89.8%, with the sequence from Malaysia being even more dissimilar. Molecular phylogenies consistently placed these sequences together in a clade that we refer to as the Paramyxidium clade that is strongly associated with the Myxidium clade (sensu stricto). We erect the genus Paramyxidium n. g. (Myxidiidae) to accommodate these histozoic taxa, and transfer Myxidium giardi as Paramyxidium giardi Cépède, 1906 n. comb. as the type-species.ConclusionsThere is not a single species of Myxidium (M. giardi) causing systemic infections in eels in Iceland. There are three species, confirmed with a robust phylogeny, one of which represents Paramyxidium giardi n. comb. Additional species probably exist that infect different tissues in the eel and the site of infection in the host fish is an important diagnostic feature for this group (Paramyxidium n. g. clade). Myxospore morphology is generally conserved in the Paramyxidium clade, although actual spore dimensions can vary between some species. Paramyxidium spp. are currently only known to infect fishes from the Elopomorpha.

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“…The myxosporean species Paramyxidium giardi was originally described as a member of the genus Myxidium , from infections in the kidney of European eel Anguilla anguilla (Linnaeus, 1758) in France (Cépède, 1906). Over time, numerous reports of this species were performed from infections occurring in multiple organs of anguillid eels worldwide (Ishii, 1915; Fujita, 1927; Hine, 1975, 1978, 1980; Copland, 1981; Treasurer and Cox, 1997), including specimens of A. anguilla from Portuguese estuaries (Ventura and Paperna, 1984; Azevedo et al ., 1989; Saraiva and Chubb, 1989; Saraiva and Eiras, 1996; Hermida et al ., 2008). In 1993, Benajiba and Marques Rocha et al , 2019 a identified the actinosporean counterpart of P. giardi as belonging to the aurantiactinomyxon collective group.…”

Section: Introductionmentioning

confidence: 99%

Molecular data infers the involvement of a marine aurantiactinomyxon in the life cycle of the myxosporean parasite Paramyxidium giardi (Cnidaria, Myxozoa)

et al. 2019

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An aurantiactinomyxon type is described from the marine naidid Tubificoides pseudogaster (Dahl, 1960), collected from the lower estuary of a Northern Portuguese River. This type constitutes the first of its collective group to be reported from Portugal, and only the fourth described from a marine oligochaete worldwide. Extensive morphological comparisons of new aurantiactinomyxon isolates to all known types without available molecular data are proposed to be unnecessary, given the artificiality of the usage of morphological criteria for actinosporean differentiation and the apparent strict host specificity of the group. Recognition of naidid oligochaetes as the hosts of choice for marine types of aurantiactinomyxon and other collective groups, suggests that the family Naididae played a preponderant role in the myxosporean colonization of estuarine communities. Molecular analyses of the type in study further infer its involvement in the life cycle of Paramyxidium giardi (Cépède, 1906) Freeman and Kristmundsson, 2018, a species that infects the kidney of European eel Anguilla anguilla (Linnaeus, 1758) and that has been reported globally, including from Portuguese waters. The low intraspecific difference registered in relation to Icelandic isolates of P. giardi (0.6%) is hypothesized to result from the emergence of genotypically different subspecies due to geographic isolation.

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Variations in the spores ofMyxidium zealandicumHine, 1975 (Protozoa: Myxosporidea)

Cited by 15 publications

References 6 publications

Ultrastructural aspects of Myxidium giardi (Myxozoa, Myxosporea), parasite of the European eel Anguilla Anguilla

Ultrastructural aspects of Myxidium giardi (Myxozoa, Myxosporea), parasite of the European eel Anguilla Anguilla

Studies of Myxidium giardi Cépède, 1906 infections in Icelandic eels identifies a genetically diverse clade of myxosporeans that represents the Paramyxidium n. g. (Myxosporea: Myxidiidae)

Molecular data infers the involvement of a marine aurantiactinomyxon in the life cycle of the myxosporean parasite Paramyxidium giardi (Cnidaria, Myxozoa)

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