The demise of a class of protists: taxonomic and nomenclatural revisions proposed for the protest phylum Myxozoa Grassé, 1970

1994 ◽  
Vol 72 (5) ◽  
pp. 932-937 ◽  
Author(s):  
M. L. Kent ◽  
L. Margolis ◽  
J. O. Corliss
Keyword(s):  
Life Cycle ◽  
Tubifex Tubifex ◽  
Salmonid Fishes ◽  
Myxobolus Cerebralis ◽  
Aquatic Oligochaetes ◽  
As Species ◽  
Collective Group ◽  
Host Life ◽  
Myxosporean Species ◽  
Species Inquirendae

The phylum Myxozoa has been considered to comprise two classes, Myxosporea Bütschli, 1881 (primarily of fishes) and Actinosporea Noble in Levine et al., 1980 (primarily of aquatic oligochaetes). About 10 years ago it was demonstrated that the life cycle of Myxobolus cerebralis Hofer, 1903 (Myxobolidae: Platysporina) of salmonid fishes requires transformation of the myxosporean into an actinosporean stage in the oligochaete worm Tubifex tubifex (Tubificidae), and that the stage infective to fish is the actinosporean spore. This type of two-host life cycle has now been demonstrated or strongly implicated for 14 myxosporean species, belonging to 6 genera in 4 families. In light of these findings, the taxonomy of the Myxozoa is revised. We propose the following: suppression of the newer class Actinosporea and the order Actinomyxidia Štolc, 1899; and suppression of all families in the Actinosporea except Tetractinomyxidae. This family and its one genus, Tetractinomyxon Ikeda, 1912, are transferred to the order Multivalvulida Shulman, 1959 (Myxosporea). We also propose that actinosporean generic names be treated as collective-group names, thus they do not compete in priority with myxosporean generic names. Triactinomyxon dubium Granata, 1924 and Triactinomyxon gyrosalmo Wolf and Markiw, 1984 are suppressed as junior synonyms of Myxobolus cerebralis. The myxosporean stage of no other previously named actinosporean has been identified. Other actinosporean species are therefore retained as species inquirendae until their myxosporean stages are identified. A revised description of the phylum Myxozoa is provided that includes our proposed taxonomic and nomenclatural changes.

A Revision of the Subfamily Microscaphidiinae (Platyhelminthes, Digenea, Microscaphidiidae) Parasitic in Marine Turtles (Reptilia, Chelonia)

1986 ◽  
Vol 34 (2) ◽  
pp. 241 ◽  
Author(s):  
D Blair
Keyword(s):  
Green Turtle ◽  
Chelonia Mydas ◽  
Nomen Nudum ◽  
Taxonomic Significance ◽  
Marine Turtles ◽  
As Species ◽  
First Time ◽  
Species Inquirendae

A revision of the subfamily Microscaphidiinae Looss, 1900 is presented and characters of taxonomic significance discussed. The genus Microscaphidium Looss, 1900, contains M. reticulare (van Beneden, 1859) Looss, 1901 (synonyms M. japonicum Oguro, 1941; M. caballeroi Groschaft, 1977); M. aberrans Looss, 1902 (synonym M. reticulare in part); and M, warui, sp. nov. Confusion in the literature over the identities of M. reticulare and M. aberrans is discussed. A neotype is selected for the former species and a lectotype for the latter. Polyangium linguatula (Looss, 1899) Looss, 1902 (synonyms P. miyajimai Kobayashi, 1921; P. colymbi Poche, 1925; P. longiseminale Chattopadhyaya, 1972) is the sole species in Polyangium Looss, 1902. The genus Angiodictyum Looss, 1902 contains A. parallelum (Looss, 1901) Looss, 1902; A. posterovitellatum Chattopadhyaya, 1972; A. longum, sp, nov.; A. glossoides, sp. nov. Polygorgyra, gen. nov., is proposed for P. cholados, sp. nov. Microscaphidium chelonei Chattopadhyaya, 1972 nec Mehrotra, 1973 and Angiodictyum anteroporum Chattopadhyaya, 1972 are regarded as species inquirendae. Microscaphidium chelonei Mehrotra, 1973 nec Chattopadhyaya, 1972 is a nomen nudum. The following species are recorded for the first time from the green turtle, Chelonia mydas (L.) in Australian waters: Microscaphidium reticulare; M. aberrans; M. warui; Angiodictyum posterovitellatum; A. longum; Polygorgyra cholados.

scholarly journals Prevalence and susceptibility of infection to Myxobolus cerebralis, and genetic differences among populations of Tubifex tubifex

2002 ◽  
Vol 51 ◽  
pp. 113-121 ◽  
Author(s):  
KA Beauchamp ◽  
M Gay ◽  
GO Kelley ◽  
M El-Matbouli ◽  
RD Kathman ◽  
...  
Keyword(s):  
Genetic Differences ◽  
Tubifex Tubifex ◽  
Myxobolus Cerebralis

scholarly journals Checklist of Aquatic Oligochaetes Species in Tigris–Euphrates River basin

2014 ◽  
Vol 11 (3) ◽  
pp. 1397-1404 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Single Species ◽  
Abundant Species ◽  
Tubifex Tubifex ◽  
Euphrates River ◽  
Tigris River ◽  
Limnodrilus Hoffmeisteri ◽  
Frequent Species ◽  
Aquatic Oligochaetes ◽  
Stylaria Lacustris ◽  
Tubificid Worms

A total of 60 species of aquatic oligochaetes were identified in different sites within Tigris-Euphrates basin / Iraq, including River Tigris, River Euphrates, Southern marshes ( Al-Haweiza , Al-Hammar and Al-Chebaiesh ) , Shutt Al-Germa, and Shatt Al-Arab. In River Euphrates 39 species were identified, 40 species from River Tigris and 32 species from Shatt-Al-Arab and southern marshes.The identified species were classified as four species of Family Aeolosomatidae, 54 species of Naididae ( 31 Naidinae , 8 Pristininae and 15 Tubificid worms), one species of each of Lumbriculidae ( Lumbriculus variegates ) and Lumbricidae ( Eiseiella tetraedra). Among Aeolosomatidae , Aelosoma aquaternarium, A. Liedyi, A. variegatum and A. hemprichi, in which, A. variegatum was the most frequent species, found in Euphrates river. Naidinae community were represented by five species of genus Chaetogaster, two species of each of Paranais, Slavina, & Stylaria, four species of Allonais , and seven species of each of Dero and Nais, in addition to Stephensoniana trivandrana, Specaria josinae and Ophidonais serpentina. Nais variabilis was the most abundant and frequent species in River Tigris while Stylaria lacustris & Ophidonais serpentina are abundant in River Euphrates . Species of Pristininae were representative by four species of genus Pristina and three species of genus pristinella, among them Priatina longiseta is the most abundant species.Tubificid worms, Branchuira sowerbyi and Limnodrilus hoffmeisteri were the most frequent and abundant species in the surface sediments of Iraqi waters. Beside L. hoffmeisteri , other five species of Limnodrilus, two species of Potomothrix, and a single species of Tubifex tubifex , Embolocephalus velutinus, Aulodrilus piguetia, Psammoryctides moravicus and Rhyacodrilus coccineus were recorded.

Whirling Disease: Reviews and Current Topics

2002 ◽  
Keyword(s):  
Life Cycle ◽  
Developmental Stages ◽  
Small Subunit ◽  
Fish Host ◽  
Complex Life Cycle ◽  
Developmental Cycle ◽  
Myxobolus Cerebralis ◽  
Rdna Sequences ◽  
Complex Development ◽  
The One

<em>ABSTRACT. Myxobolus cerebralis </em>possesses unique phenotypic and genotypic characteristics when compared with other histozoic parasites from the phylum Myxozoa. The parasite infects the cartilage and thereby induces a serious and potentially lethal disease in salmonid fish. Comparisons of the small subunit ribosomal DNA (ssu rDNA) sequences of <em>M. cerebralis </em>to other myxozoans demonstrate that the parasite has evolved separately from other <em>Myxobolus </em>spp. that may appear in cartilage or nervous tissues of the fish host. <em>Myxobolus cerebralis </em>has a complex life cycle involving two hosts and numerous developmental stages that may divide by mitosis, endogeny, or plasmotomy, and, at one stage, by meiosis. In the salmonid host, the parasite undergoes extensive migration from initial sites of attachment to the epidermis, through the nervous system, to reach cartilage, the site where sporogenesis occurs. During this migration, parasite numbers may increase by replication. Sporogenesis is initiated by autogamy, a process typical of pansporoblastic myxosporean development that involves the union of the one cell (pericyte) with another (sporogonic). Following this union, the sporogonic cell will give rise to all subsequent cells that differentiate into the lenticular shaped spore with a diameter of approximately 10 µm. This spore or myxospore is an environmentally resistant stage characterized by two hardened valves surrounding two polar capsules with coiled filaments and a binucleate sporoplasm cell. In the fish, these spores are found only in cartilage where they reside until released from fish that die or are consumed by other fish or fish-eating animals (e.g., birds). Spores reaching the aquatic sediments can be ingested and hatch in susceptible oligochaete hosts. The released sporoplasm invades and then resides between cells of the intestinal mucosa. In contrast to the parasite in the fish host, the parasite in the oligochaete undergoes the entire developmental cycle in this location. This developmental cycle involves merogony, gametogamy or the formation of haploid gametes, and sporogony. The actinosporean spores, formed at the culmination of this development, are released into the lumen of the intestine, prior to discharging into the aquatic environment. The mechanisms underlying the complex development of <em>M. cerebralis</em>, and its interactions with both hosts, are poorly understood. Recent advances, however, are providing insights into the factors that mediate certain phases of the infection. In this review, we consider known and recently obtained information on the taxonomy, development, and life cycle of the parasite.

scholarly journals Amblyomma rotundatum (Koch, 1844) (Acari: Ixodidae) two-host life-cycle on Viperidae snakes

2010 ◽  
Vol 19 (3) ◽  
pp. 174-178 ◽  
Author(s):  
Daniel Sobreira Rodrigues ◽  
Ricardo Maciel ◽  
Lucas Maciel Cunha ◽  
Romário Cerqueira Leite ◽  
Paulo Roberto de Oliveira
Keyword(s):  
Life Cycle ◽  
North America ◽  
Relative Humidity ◽  
Total Duration ◽  
Ixodid Tick ◽  
Natural Conditions ◽  
South Central ◽  
Controlled Conditions ◽  
In Captivity ◽  
Host Life

Amblyomma rotundatum is an ixodid tick that infests ectothermic animals and reproduces exclusively by parthenogenesis. This tick has been frequently reported to infest reptiles and amphibians, under natural conditions and sometimes in captivity. It was described in Brazil and several other countries of South, Central and North America. Although many studies have reported aspects of its biology, none of them has used regularly either ophidian as hosts, or controlled temperature, humidity and luminosity for parasitic stages. The objective of this experiment was to study the life cycle of A. rotundatum feeding on Viperidae snakes under room controlled conditions at 27 ± 1 ºC temperature, 85 ± 10% relative humidity and 12:12 hours photoperiod for parasitic stages, and under B.O.D incubator conditions at 27 ± 1 ºC temperature, 85 ± 10% relative humidity and scotophase for non-parasitic stages. The total duration of the life cycle ranged from 56 to 163 days (mean of 105 days). Two-host life cycle was observed for most of the ixodid population studied.

Nacobbus aberrans (Thorne, 1935) Thorne & Allen, 1944 (Nematoda: Pratylenchidae); a nascent species complex revealed by RFLP analysis and sequencing of the ITS-rDNA region

Nematology ◽  
2003 ◽  
Vol 5 (3) ◽  
pp. 441-451 ◽  
Author(s):  
David Hunt ◽  
Rosa Manzanilla-López ◽  
Alex Reid
Keyword(s):  
Species Complex ◽  
Rflp Analysis ◽  
Its Rdna ◽  
Molecular Characterisation ◽  
Separate Species ◽  
Banding Patterns ◽  
As Species ◽  
The Usa ◽  
Nacobbus Aberrans ◽  
Species Inquirendae

AbstractTwelve populations of Nacobbus aberrans, sensu lato, from Mexico, Bolivia, Peru, Ecuador and Argentina were subjected to molecular analysis of their genetic variability. RFLP banding patterns revealed three groups: i) Mexico, Ecuador and Argentina 1 populations; ii) Bolivia and Peru populations; iii) Argentina 2 population. These differences were confirmed by sequencing the ITS rDNA region. Depth of branching was strongly supportive of the presence of three separate species, thus supporting the hypothesis that N. aberrans s.l. is indeed a species complex. The populations from Mexico, Ecuador and Argentina 1 are attributed to N. aberrans s.s., although this requires confirmation by molecular characterisation of N. aberrans from the type locality in the USA; those from Bolivia and Peru are attributed to N. bolivianus Lordello, Zamith & Boock, 1961 with Argentina 2 regarded as representing another taxon. Nacobbus serendipiticus and N. batatiformis are removed from synonymy under N. aberrans s.l . and regarded as species inquirendae . Consistent minor banding patterns in the RFLP profiles may indicate that the genus reproduces predominantly by parthenogenesis.

Encystment site affects the reproductive strategy of a progenetic trematode in its fish intermediate host: is host spawning an exit for parasite eggs?

Parasitology ◽  
2011 ◽  
Vol 138 (9) ◽  
pp. 1183-1192 ◽  
Author(s):  
KRISTIN K. HERRMANN ◽  
ROBERT POULIN
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Body Cavity ◽  
Life Cycles ◽  
Temperature Changes ◽  
Fish Spawning ◽  
Second Intermediate Host ◽  
Host Life ◽  
Major Factors ◽  
Fish Hosts

SUMMARYEach transmission event in complex, multi-host life cycles create obstacles selecting for adaptations by trematodes. One such adaptation is life cycle abbreviation through progenesis, in which the trematode precociously matures and reproduces within the second intermediate host. Progenesis eliminates the need for the definitive host and increases the chance of life cycle completion. However, progenetic individuals face egg-dispersal challenges associated with reproducing within metacercarial cysts in the tissues or body cavity of the second intermediate host. Most progenetic species await host death for their eggs to be released into the environment. The present study investigated temporal variation of progenesis in Stegodexamene anguillae in one of its second intermediate fish hosts and the effect of the fish's reproductive cycle on progenesis. The study involved monthly sampling over 13 months at one locality. A greater proportion of individuals became progenetic in the gonads of female fish hosts. Additionally, progenesis of worms in the gonads was correlated with seasonal daylight and temperature changes, major factors controlling fish reproduction. Host spawning events are likely to be an avenue of egg dispersal for this progenetic species, with the adoption of progenesis being conditional on whether or not the parasite can benefit from fish spawning.

Paronchocerca struthionus n.sp. (Nematoda: Filarioidea) from ostriches (Struthio camelus), with a redescription of Paronchocerca ciconiarum Peters, 1936 and a review of the genus

1986 ◽  
Vol 64 (11) ◽  
pp. 2480-2491 ◽  
Author(s):  
Cheryl M. Bartlett ◽  
Roy C. Anderson
Keyword(s):  
Pulmonary Arteries ◽  
Valid Species ◽  
Single Family ◽  
Glandular Oesophagus ◽  
Struthio Camelus ◽  
Incertae Sedis ◽  
As Species ◽  
The Right ◽  
Species Inquirendae ◽  
Adaptive Zone

Paronchocerca struthionus n.sp. (Onchocercidae: Splendidofilariinae) from the lungs of Struthio camelus L. (Struthionidae) from West Africa has a long, sacculate glandular oesophagus similar to that of Paronchocerca limboonkengi (Hoeppli and Hsü, 1929) n.comb. (= Lemdana limboonkengi), P. bambusicolae, P. tonkinensis, and P. sonini. It can be distinguished by delicate annular cuticular thickenings and, in the male, a preanal hypodermal swelling, three pairs of circumanal papillae, and the length of the right spicule in relation to the length of the tail. Also, lateral, postanal papillae are absent, although inconspicuous subterminal papillae are present. Paronchocerca ciconiarum Peters, 1936, the type species, is redescribed on the basis of material from the pulmonary arteries of Leptoptilus crumeniferus (Lesson) (Ciconiidae) from Uganda. Seventeen valid species are recognized in the genus. Paronchocerca sanguinisardeae, P. choprai, and P. badamii are regarded as species inquirendae and P. alii, as a species incertae sedis. Among larger avian filarioid genera, Paronchocerca appears unique in that each species seems restricted to a single family of birds. Paronchocerca may have become established in early Ornithurae and subsequently persisted in some of the "primitive" birds, as well as having transferred to "modern" groups which now occupy the aquatic adaptive zone originally occupied by the earliest Ornithurae. Paronchocerca apparently has been largely unsuccessful in transferring to other modern groups.

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