Coryphella verrucosa

Coryphella verrucosa
Coryphella verrucosa from Gulen Dive Resort, Norway.
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Heterobranchia
Order:	Nudibranchia
Suborder:	Cladobranchia
Superfamily:	Fionoidea
Family:	Coryphellidae
Genus:	Coryphella
Species:	C. verrucosa
Binomial name
Coryphella verrucosa (M. Sars, 1829) [1]
Synonyms [2]
Aeolidia verrucosaM. Sars, 1829 (incorrect subsequent spelling) Coryphella mananensis(Stimpson, 1853) (junior synonym) Coryphella pseudoverrucosaMartynov, Sanamyan & Korshunova, 2015 junior subjective synonym Coryphella robustaTrinchese, 1874 Coryphella rufibranchialis(G. Johnston, 1832) Coryphella rufibranchialis chocolataBalch, 1908 (junior synonym) Coryphella rufibranchialis mananensis(Stimpson, 1853) (junior synonym) Coryphella rufibranchialis var. chocolataBalch, 1909 (junior synonym) Eolidia embletoniG. Johnston, 1835 Eolidia verrucosaM. Sars, 1829 Eolis diversaCouthouy, 1839 Eolis mananensisStimpson, 1853 Eolis rufibranchialisG. Johnston, 1832 Flabellina pseudoverrucosa(Martynov, Sanamyan & Korshunova, 2015) Flabellina verrucosa(M. Sars, 1829)

Coryphella verrucosa, is a species of sea slug, an aeolid nudibranch, a marine gastropod mollusc in the family Coryphellidae. ^[2]

It is found on either side of the northern part of the Atlantic Ocean.

Distribution

The type locality of Coryphella verrucosa is Bergen, Norway. Current thinking is that it is widespread in the North Atlantic Ocean but that specimens found in the North Pacific Ocean are a closely related species. ^[3] In North America, its range includes the Gulf of St Lawrence and the Gulf of Maine. ^[2] Animals from British Columbia and Alaska differ significantly in colour pattern and are probably a sibling species, described as Coryphella longicaudata O'Donoghue, 1922. ^[4] Coryphella pseudoverrucosa has recently been described as a separate species from the NW Pacific. ^{[5] [6]}

Description

The original description of this species is of an animal with unusually short, rounded cerata, hence the name verrucosa. ^[7] The name has been extensively used for animals of different appearance, with long cerata, including Coryphella rufibranchialis , the type species of the genus Coryphella .

The body of Coryphella verrucosa is translucent white. The tail is elongated and pointed with a mid-dorsal line of opaque white pigment in which there are round translucent spots. This white line may extend along the back amongst the cerata from the tail, breaking up into spots. In different parts of its range this species has differently coloured forms, which may be different species. In some places the digestive gland in the cerata is red while in other locations, cerata with brown digestive gland predominate, though it is known that the colour of the digestive gland in species of Coryphellidae is dependent on diet. ^[8] There is also considerable variation in the colouring of the tips of the cerata, from narrow broken rings (F. rufibranchialis form) through broad white bands to white almost covering the tips of the cerata in the typical form. The oral tentacles have a broad white stripe on the upper surfaces.

The maximum recorded body length is 35 mm ^[9] or up to 40 mm (1.6 in).

This nudibranch is similar in appearance to Microchlamylla gracilis and many other species of Flabellinidae. ^[8]

Ecology

In Norway this is a common species in depths of 2–10 metres (6 ft 7 in – 32 ft 10 in). ^[1] Minimum recorded depth is 0 m and maximum recorded depth is 183 m. ^[9] Flabellina verrucosa sensu lato has been reported at depths down to about 300 metres (980 ft) and seems to inhabit both sandy and rocky habitats. ^[3]

Coryphella verrucosa grazes on sessile invertebrates on the sea bed. It also feeds on detritus and plankton. In the United Kingdom, it lives almost exclusively on the oaten pipes hydroid ( Tubularia indivisa ) whilst the juveniles have a wider diet range. ^[10]

Coryphella verrucosa is a hermaphrodite but self-fertilisation does not occur. Two adults engage in an elaborate touching ritual that was at first thought to be agonistic behaviour. The tentacles touch each other and are then withdrawn repeatedly and there is biting, lunging and sidling. The actual act of copulation is very quick. ^[11] The eggs are laid in a gelatinous string neatly coiled in a spiral on the seabed. ^[10] After hatching, the veliger larvae drift as part of the plankton, eventually settling on the seabed. ^[11]

As in most other Aeolid nudibranchs Coryphella verrucosa has the ability to incorporate nematocysts from its prey into the tissue of its cerata as a defence. ^[12] It was found experimentally that when the nudibranch was kept in the vicinity of certain predators such as the common sunstar ( Crossaster papposus ), the bergall ( Tautogolabrus adspersus ) (a fish) and the shore crab Carcinus maenas , it incorporated more nematocysts than it did in a predator-free environment. ^[12]

References

1. Sars M. (1829). Bidrag til soedyrene naturhistorie, Pt. 1: pp. 1-59, pls. 1-6. Bergen.
2. Gofas, S. (2015). Flabellina verrucosa. In: MolluscaBase (2015). Accessed through: World Register of Marine Species on 2016-01-26.
3. Telnes, K. (2012) Nudibranch - Flabellina verrucosa. Seawater Norway, Retrieved July 04, 2012
4. O'Donoghue, C. H., (1922). Nudibranchiate Mollusca from the Vancouver Island region. III. Records of species and distribution. Transactions of the Royal Canadian Institute 14(1):145-167, pls. 5-6.
5. Martynov AV, Sanamyan NP, Korshunova TA (2015) New data on the opisthobranch molluscs (Gastropoda: Opisthobranchia) of waters of Commander Islands and Far-Eastern seas of Russia. In: Conservation of biodiversity of Kamchatka and coastal waters. Proceedings of XV international scientific conference Petropavlovsk-Kamchatsky. Kamchat Press, Petropavlovsk-Kamchatsky, 55–69. [In Russian]
6. Korshunova, T.; Martynov, A.; Bakken, T.; Evertsen, J.; Fletcher, K.; Mudianta, W.; Saito, H.; Lundin, K.; Schrödl, M.; Picton, B. (2017). Polyphyly of the traditional family Flabellinidae affects a major group of Nudibranchia: aeolidacean taxonomic reassessment with descriptions of several new families, genera, and species (Mollusca, Gastropoda). ZooKeys. 717: 1-139.
7. Rudman, W.B., 2003 (Apr 30). Comment on Re: Flabellina? from Norway by Jussi Evertsen. [Message in] Sea Slug Forum. Australian Museum, Sydney.
8. Rudman, W.B., 1999 (August 27) Flabellina verrucosa (M. Sars, 1829). [In] Sea Slug Forum. Australian Museum, Sydney.
9. 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.
10. Picton, B.E. & Morrow, C.C. (2015). Coryphella rufibranchialis (Johnston, 1832). [In] Encyclopedia of Marine Life of Britain and Ireland. Accessed on 2016-1-26
11. Carefoot, Tom. "Reproduction: Mate selection and copulation". A snail's odyssey: Nudibranchs and relatives. Archived from the original on 2014-12-05. Retrieved 2012-12-24.
12. Frick, K. (2003). "Response in nematocyst uptake by the nudibranch Flabellina verrucosa to the presence of various predators in the Southern Gulf of Maine". Biological Bulletin. 205 (3): 367–376. doi:10.2307/1543299. JSTOR   1543299. PMID   14672990. S2CID   39067662.

• Martynov A.V., Sanamyan N.P., Korshunova T. A. (2015). [in Russian] New data on the opisthobranch molluscs (Gastropoda: Opisthobranchia) of waters of Commander Islands and Far-Eastern seas of Russia. In: Conservation of biodiversity of Kamchatka and coastal waters. Proceedings of XV international scientific conference Petropavlovsk-Kamchatsky. Kamchat Press: Petropavlovsk-Kamchatsky, Russia. pp. 55–69, pl. 2-6.

External links

• Korshunova, T.; Martynov, A.; Bakken, T.; Evertsen, J.; Fletcher, K.; Mudianta, W.; Saito, H.; Lundin, K.; Schrödl, M.; Picton, B. (2017). Polyphyly of the traditional family Flabellinidae affects a major group of Nudibranchia: aeolidacean taxonomic reassessment with descriptions of several new families, genera, and species (Mollusca, Gastropoda). ZooKeys. 717: 1-139