{{short description|Species of worm}} {{Speciesbox | image = | image_caption = | genus = Microcotyle | species = helotes | authority = Sandars, 1944 | synonyms = *''Microcotyle (Microcotyle) helotes'' <small>(Sandars, 1944) Unnithan1971</small><ref name="Sandars1944"/><ref name="Unnithan1971"/> }}
'''''Microcotyle helotes''''' is a species of monogenean, parasitic on the gills of a marine fish. It belongs to the family Microcotylidae.<ref name="Sandars1944">Sandars, Dorothea F. (1944). A contribution to the knowledge of the Microcotylidae of Western Australia. Transactions of the Royal Society of South Australia, 68(1), 67-81. [https://biodiversitylibrary.org/page/41564495 PDF in BHL] {{open access}}</ref>
==Taxonomy== ''Microcotyle helotes'' was described and illustrated by Sandars (1944) based on 11 specimens from the gills of the eastern striped grunter, ''Helotes sexlineatus'' (Terapontidae) from off Safety Bay, Western Australia.<ref name="Sandars1944"/> Unnithan (1971) placed ''M. helotes'' in the nominal subgenus ''Microcotyle'' as ''Microcotyle (Microcotyle) helotes''.<ref name="Unnithan1971">Unnithan, R. V. (1971). On the functional morphology of a new fauna of Monogenoidea on fishes from Trivandrum and environs. Part IV. Microcotylidae sensu stricto and its repartition into subsidiary taxa. American Midland Naturalist, 366-398.</ref> However, this combinaison was suppressed by Mamaev in 1986.<ref name="Mamaev1986">Mamaev, Y. L. (1986). The taxonomical composition of the family Microcotylidae Taschenberg, 1879 (Monogenea). Folia Parasitologica, 33, 199-206. [https://folia.paru.cas.cz/pdfs/fol/1986/03/02.pdf PDF] {{open access}}</ref> This monogenean was redescribed and illustrated by Dillon & Hargis (1985) based on 2 adults and one 1 juvenile from the type-host and locality.<ref name="Dillon&al1985">Dillon, W. A., Hargis Jr, W. J., & Harrises, A. E. (1985). Monogeneans from the southern Pacific Ocean: Polyopisthocotyleids from the Australian fishes. The subfamily Microcotylinae. Zoologicheskiy Zhurnal [1984], 63, (3), 348-359. Translation Series Number 32 of the Virginia Institute of Marine Science, The College of William and Mary, Gloucester Point, Virginia 23062, U.S.A. March, 1985 [http://www.vims.edu/GreyLit/VIMS/trans32 PDF of English Translation from Russian] {{open access}}</ref> Although Williams (1991) recovered specimens of ''Microcotyle helotes'' from the type-host and a second Terapontidae, ''Pelsartia humeralis'', from the type locality, he redescribed ''Microcotyle helotes'' from ''Pelsartia humeralis'' only.<ref name="Williams1991">{{cite journal|last1=Williams|first1=Alan|title=Monogeneans of the families Microcotylidae Taschenberg, 1879 and Heteraxinidae Price, 1962 from Western Australia, including the description of ''Polylabris sandarsae'' n. sp. (Microcotylidae)|journal=Systematic Parasitology|volume=18|issue=1|year=1991|pages=17–43|issn=0165-5752|doi=10.1007/BF00012221}}</ref> Minor differences were noted in the redescriptions.<ref name="Dillon&al1985"/><ref name="Williams1991"/> Williams (1991) noted that examination of a large series of specimens from both hosts showed them to be identical.<ref name="Williams1991"/>
==Morphology== ''Microcotyle helotes'' has the general morphology of all species of ''Microcotyle'', with a symmetrical elongated body of medium size, comprising an anterior part which contains most organs and a posterior part called the haptor. The haptor is symmetrical, and bears 62 clamps, arranged as two rows, one on each side. The clamps of the haptor attach the animal to the gill of the fish. There are also two buccal septated suckers at the anterior extremity. The digestive organs include an anterior, terminal mouth, a circular pharynx, an oesophagus dividing shortly behind the genital atrium and a posterior intestine with two lateral branches provided with numerous secondary branches; the branches extends into the haptor. Each adult contains male and female reproductive organs. The reproductive organs include an anterior genital atrium, armed with numerous minute spines, a medio-dorsal vagina, a single ovary and 14 irregular testes which are posterior to the ovary.<ref name="Sandars1944"/>
==Hosts and localities== thumb|left|The eastern striped grunter, ''Helotes sexlineatus'' is the type host of ''Microcotyle helotes'' [[File:Therapon theraps Ford 18.jpg|thumb|left|The sea trumpeter ''Terapon theraps'' is also host of ''Microcotyle helotes'']] The eastern striped grunter, ''Helotes sexlineatus'' (Terapontidae) is the type host of ''Microcotyle helotes''.<ref name="Sandars1944"/><ref name="Dillon&al1985"/><ref name="Williams1991"/> It was redescribed from others Terapontidae; ''Pelsartia humeralis'',<ref name="Williams1991"/> and the sea trumpeter ''Terapon theraps''.<ref name="Zhangetal2001">Zhang J.Y., Yang T.B. & Liu L. (2001) Monogeneans of Chinese marine fishes. Beijing: Agriculture Press, 400 pp. (In Chinese)</ref> ''Microcotyle helotes'' was first described from fishes caught off Western Australia.<ref name="Sandars1944"/> This monogenean was reported again from the type locality,<ref name="Williams1991"/><ref name="Dillon&al1985"/> and from South China Sea.<ref name="Zhangetal2001"/>
== References == {{Reflist}}
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Category:Microcotyle Category:Parasites of fish Category:Animals described in 1944 Category:Flatworms of Australia