''Megadenus'' is a
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
sea snail
Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...
s,
marine gastropod
Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, freshwater, and fro ...
mollusk
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...
s in the
family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Eulimidae
Eulimidae is a family of very small parasitic sea snails, marine gastropod mollusks in the superfamily Vanikoroidea.
Description
These small parasitic snails live on (or in some cases in) the bodies of echinoderms such as sea cucumbers, se ...
.
[Bouchet, P.; Gofas, S. (2014). Megadenus Rosén, 1910. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=137977 on 2014-12-21]
Species
Species within this genus include the following:
* ''
Megadenus cantharelloides''
(Humphreys & Lützen, 1972)
* ''
Megadenus holothuricola''
(Rosen, 1910)
* ''
Megadenus oneirophantae''
(Bouchet & Lützen, 1980)
* ''
Megadenus voeltzkovi''
(Schepman & Nierstrasz, 1914)
''Megadenus atrae''
[Takano, T., Warén, A., & Kano, Y. (2017). Megadenus atrae n. sp., an endoparasitic eulimid gastropod (Mollusca) from the black sea cucumber Holothuria atra Jaeger (Aspidochirotida: Holothuriidae) in the Indo-West Pacific. Systematic Parasitology 94: 699-709.
]
This parasite was discovered to reside in the cloacal chamber of the black sea cucumber ''Holothuria atra''. ''M. atrae'' differs from the other species by having moderately long and thick developed collar of the proboscis that contains a constricted apical pseudopallium. Its pseudopallium can be distinguished by its cauldron-like structure. In addition to a rounded basal lip of the shell aperture. ''M. atrae'' is found in black sea cucumbers of which are in India, Japan, Australia and New Caledonia.
''M.atrae'' exhibit sexual dimorphism. Female species of ''M. atrae'' are slightly bigger than male species as they have a slightly larger shell. Males are able to switch sexes in the absence of a female. The parasite is suggested to have less tolerance to low water temperatures than its host species. Furthermore, this limits its ability to mate and confines it to specific water temperatures of which its host must be in alongside the opposite sex.
;Species brought into synonymy:
* ''Megadenus arrhynchus''
(Ivanov, 1937): synonym of ''
Paramegadenus arrhynchus''
(Ivanov, 1937)
* ''Megadenus cysticola''
(Koehler & Vaney, 1925): synonym of ''
Sabinella cysticola
''Sabinella'' is a genus of very small ectoparasitic sea snails, marine gastropod mollusks or micromollusks in the Eulimidae family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) ...
''
(Koehler & Vaney, 1925)
References
* Rosén N. 1910. ''Zur Kenntnis der parasitischen Schnecken.'' Kongliga Fysiografiska Sällskapets Handlingar, n. f., 21(4): 1-67
* Warén A. (1984) A generic revision of the family Eulimidae (Gastropoda, Prosobranchia). Journal of Molluscan Studies suppl. 13: 1-96.
page(s): 53.
External links
To World Register of Marine Species
Eulimidae
{{Eulimidae-stub