Onchidoris proxima

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Onchidoris proxima
AlderHancockFam1Plate9.jpg
Onchidoris proxima in the original combination Doris proxima in Alder & Hancock, 1854, fig 10-16
Scientific classification
Kingdom:
Animalia
Phylum:
Mollusca
Class:
Gastropoda
(unranked):
clade Heterobranchia
clade Euthyneura
clade Nudipleura
clade Nudibranchia
clade Euctenidiacea
clade Doridacea
Superfamily:
Onchidoridoidea
Family:
Onchidorididae
Genus:
Onchidoris
Species:
O. proxima
Binomial name
Onchidoris proxima
(Alder & Hancock, 1854) [1]
Synonyms [2]
  • Doris proximaAlder & Hancock, 1854
  • Adalaria proxima(Alder & Hancock, 1854)

Onchidoris proxima is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae. [2] This species is found in the northeastern and northwestern parts of the Atlantic Ocean. It is also reported from the northeastern Pacific Ocean. Previously in the genus Adalaria this species was moved to Onchidoris as a result of a molecular phylogeny study. [3]

In biology, a species ( ) is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. While these definitions may seem adequate, when looked at more closely they represent problematic species concepts. For example, the boundaries between closely related species become unclear with hybridisation, in a species complex of hundreds of similar microspecies, and in a ring species. Also, among organisms that reproduce only asexually, the concept of a reproductive species breaks down, and each clone is potentially a microspecies.

Sea slug group of marine invertebrates with varying levels of resemblance to terrestrial slugs

Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatures known as sea slugs are actually gastropods, i.e. they are sea snails that over evolutionary time have either completely lost their shells, or have seemingly lost their shells due to having a greatly reduced or internal shell. The name "sea slug" is most often applied to nudibranchs, as well as to a paraphyletic set of other marine gastropods without obvious shells.

Nudibranch order of molluscs

Nudibranchs are a group of soft-bodied, marine gastropod molluscs which shed their shells after their larval stage. They are noted for their often extraordinary colours and striking forms, and they have been given colourful nicknames to match, such as "clown", "marigold", "splendid", "dancer", and "dragon". Currently, about 3,000 valid species of nudibranchs are known.

Contents

Distribution

This species was described from Birkenhead on the Irish Sea coast of England. It is native to the colder parts of the north Atlantic Ocean. Its range extends from the North Sea, the Baltic Sea and the White Sea to eastern Greenland, and the eastern coast of North America as far south as Massachusetts. Its depth range reaches as deep as 60 metres (200 ft). [4] It is also known from the northern Pacific Ocean, from British Columbia to South Korea. [5]

Birkenhead town in Merseyside, England

Birkenhead is a town within the Metropolitan Borough of Wirral in Merseyside, England. Historically in Cheshire, it is on the Wirral Peninsula, along the west bank of the River Mersey, opposite the city of Liverpool. In the 2011 census, the Parliamentary constituency of Birkenhead had a population of 88,818.

Irish Sea Sea which separates the islands of Ireland and Great Britain

The Irish Sea separates the islands of Ireland and Great Britain; linked to the Celtic Sea in the south by St George's Channel, and to the Inner Seas off the West Coast of Scotland in the north by the Straits of Moyle.

England Country in north-west Europe, part of the United Kingdom

England is a country that is part of the United Kingdom. It shares land borders with Wales to the west and Scotland to the north-northwest. The Irish Sea lies west of England and the Celtic Sea lies to the southwest. England is separated from continental Europe by the North Sea to the east and the English Channel to the south. The country covers five-eighths of the island of Great Britain, which lies in the North Atlantic, and includes over 100 smaller islands, such as the Isles of Scilly and the Isle of Wight.

Description

Onchidoris proxima is oval in shape and grows to a length of about 25 mm (1 in). The head has a flattened piece of tissue above the mouth. The mantle is covered with club-shaped tubercles with pointed ends which are stiffened with calcareous spicules (spine-like structures). The body is a yellowish-orange colour, but is often quite a pale shade, especially in the northernmost part of the animal's range. The blunt-ended rhinophores (sensory tentacles on the head) are often darker in colour than the rest of the animal, and each bears up to nineteen thin plates. The anal papilla is surrounded by a ring of about twelve feathery gills. [4] This species can be confused with Onchidoris muricata , but that species is usually smaller and paler and has dorsal tubercles that have tips which are flattened. [6]

Mantle (mollusc) Part of the anatomy of molluscs

The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.

Tubercle round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal

In anatomy, a tubercle is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal.

Rhinophore

A rhinophore is one of a pair of chemosensory club-shaped, rod-shaped or ear-like structures which are the most prominent part of the external head anatomy in sea slugs, marine gastropod opisthobranch mollusks such as the nudibranchs (Nudibranchia), Sea Hares, (Aplysiomorpha) and sap-sucking sea slugs (Sacoglossa).

Ecology

Minimum recorded depth is 0 m. [7] Maximum recorded depth is 60 m. [7]

Onchidoris proxima feeds on the colonial bryozoan Electra pilosa , which is often found encrusted on the fronds of large brown algae such as Laminaria and Fucus serratus . [4] [6] It also feeds on other species of bryozoa such as Membranipora membranacea , Alcyonidium polyoum and Flustrellidra hispida if Electra is not available. [8]

Bryozoa phylum of marine invertebrates

Bryozoa are a phylum of aquatic invertebrate animals. Typically about 0.5 millimetres (0.020 in) long, they are filter feeders that sieve food particles out of the water using a retractable lophophore, a "crown" of tentacles lined with cilia. Most marine species live in tropical waters, but a few occur in oceanic trenches, and others are found in polar waters. One class lives only in a variety of freshwater environments, and a few members of a mostly marine class prefer brackish water. Over 4,000 living species are known. One genus is solitary and the rest are colonial.

<i>Electra pilosa</i> species of bryozoan

Electra pilosa is a species of colonial bryozoan in the order Cheilostomata. It is native to the northeastern and northwestern Atlantic Ocean and is also present in Australia and New Zealand.

<i>Laminaria</i> genus of algae

Laminaria is a genus of 31 species of brown algae commonly called "kelp". Some species are also referred to as tangle. This economically important genus is characterized by long, leathery laminae and relatively large size. Some species are referred to by the common name Devil's apron, due to their shape, or sea colander, due to the perforations present on the lamina. It is found in the north Atlantic Ocean and the northern Pacific Ocean at depths from 8 to 30 m. Laminaria form a habitat for many fish and invertebrates. 

Breeding takes place in late winter and spring, when the eggs are laid in coils. The eggs are fairly large, and hatch after about forty days. The larvae have a yolksac and do not feed but drift as part of the plankton before settling in suitable habitat. [5]

Plankton Organisms that live in the water column and are incapable of swimming against a current

Plankton are the diverse collection of organisms that live in large bodies of water and are unable to swim against a current. The individual organisms constituting plankton are called plankters. They provide a crucial source of food to many large aquatic organisms, such as fish and whales.

Related Research Articles

Onchidorididae family of molluscs

Onchidorididae are a taxonomic family of sea slugs, dorid nudibranchs, marine gastropod molluscs in the superfamily Onchidoridoidea.

<i>Onchidoris bilamellata</i> species of mollusc

Onchidoris bilamellata, common name the rough-mantled doris, is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusk in the family Onchidorididae.

<i>Onchidoris</i> genus of molluscs

Onchidoris is a genus of dorid nudibranchs in the family Onchidorididae. One of its members is known to prey on barnacles and the others eat bryozoans. The radula contains a rachidian tooth when fully developed, but this is vestigial in some species.

<i>Geitodoris planata</i> species of mollusc

Geitodoris planata is a species of sea slug or dorid nudibranch, a marine gastropod mollusk in the family Discodorididae.

<i>Doto cuspidata</i> species of mollusc

Doto cuspidata is a species of sea slug, a dendronotid nudibranch, a marine gastropod mollusc in the family Dotidae.

<i>Zelentia pustulata</i> species of mollusc

Zelentia pustulata is a species of sea slug, an aeolid nudibranch, a marine gastropod mollusc in the family Trinchesiidae.

<i>Onchidoris loveni</i> species of mollusc

Onchidoris loveni is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae. This species is found in the north-eastern parts of the Atlantic Ocean.

<i>Knoutsodonta depressa</i> species of mollusc

Knoutsodonta depressa is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.

<i>Knoutsodonta oblonga</i> species of mollusc

Knoutsodonta oblonga is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.

Knoutsodonta jannae is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae. It was frequently mis-identified as Onchidoris muricata. K. jannae is the type species of the genus Knoutsodonta.

<i>Onchidoris muricata</i> species of mollusc

Onchidoris muricata is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.

<i>Knoutsodonta inconspicua</i> species of mollusc

Knoutsodonta inconspicua is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.

<i>Knoutsodonta sparsa</i> species of mollusc

Knoutsodonta sparsa is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.

<i>Knoutsodonta pusilla</i> species of mollusc

Knoutsodonta pusilla is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.

Onchidoris macropompa is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.

Onchidoris olgae is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.

Onchidoris slavi is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.

Onchidoris derjugini is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.

Onchimira cavifera is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.

References

  1. ↑ Alder, J., & A. Hancock (1854) Notice of some new species of British Nudibranchiata. Annals & Magazine of Natural History, series 2, 14(80):102-105.
  2. 1 2 Bouchet, P. (2015). Onchidoris proxima (Alder & Hancock, 1854). In: MolluscaBase (2015). Accessed through: World Register of Marine Species on 2016-01-13
  3. ↑ Hallas, J.M., Simison, W.B. & Gosliner, T.M. (2016) Dating and biogeographical patterns in the sea slug genus Acanthodoris Gray, 1850 (Mollusca, Gastropoda, Nudibranchia). Molecular Phylogenetics and Evolution, 97: 19-31.
  4. 1 2 3 de Kluijver, M.J.; Ingalsuo, S.S.; de Bruyne, R.H. "Adalaria proxima". Mollusca of the North Sea. Marine Species Identification Portal. Retrieved 2014-12-28.
  5. 1 2 Rudman, W.B., 2001 (July 5) Adalaria proxima (Alder & Hancock, 1854). [In] Sea Slug Forum. Australian Museum, Sydney.
  6. 1 2 Picton, B.E. & Morrow, C.C. (2015). Adalaria proxima (Alder & Hancock, 1854). [In] Encyclopedia of Marine Life of Britain and Ireland. Accessed on 2016-01-13.
  7. 1 2 Welch J. J. (2010). "The “Island Rule” and Deep-Sea Gastropods: Re-Examining the Evidence". PLoS ONE 5(1): e8776. doi:10.1371/journal.pone.0008776.
  8. ↑ Thompson, T.E. and Brown, G.H., 1984. Biology of Opisthobranch Molluscs, Volume II. The Ray Society. 229 pages 41 plates, 40 figures.
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