Oxynoe olivacea is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of small green bubble snail

Snail

Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...

 or sea slug

Slug

Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...

, a marine

Marine (ocean)

Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 gastropod mollusk in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Oxynoidae

Oxynoidae

Oxynoidae is a family of sea snails, bubble snails, marine gastropod mollusks in the superfamily Oxynooidea, an opisthobranch group.This family has no subfamilies.-Genera:The following three genera or four are included in the family Oxynoidae:...

.

Despite a superficial resemblance, this is not a nudibranch

Nudibranch

A nudibranch is a member of what is now a taxonomic clade, and what was previously a suborder, of soft-bodied, marine gastropod mollusks which shed their shell after their larval stage. They are noted for their often extraordinary colors and striking forms...

, it is a sacoglossan, and like other Oxynoe species, it has a small, fragile, bubble-shaped shell

Gastropod shell

The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...

.

Distribution

This species is found in the Mediterranean Sea

Mediterranean Sea

The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...

. The type locality for this species is Sicily

Sicily

Sicily is a region of Italy, and is the largest island in the Mediterranean Sea. Along with the surrounding minor islands, it constitutes an autonomous region of Italy, the Regione Autonoma Siciliana Sicily has a rich and unique culture, especially with regard to the arts, music, literature,...

, Italy.

Description

Body is elongated, swollen in front of the middle, with the tail long and narrow, pleuropodial lobes partly covering the shell

Gastropod shell

The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...

, the line of their junction forming a crest or ridge the entire length of the tail. Upper side of tentacles and outer surface of pleuropodia and tail
papillose. Color above clear green, the borders of the foot and pleuropodial lobes, and ends of the tentacles margined with alternating spots of pale red and blue-black. The sole is yellowish.

The shell is external, thin, fragile, pellucid and shining, convolute and globose. The shell is truncate and slightly contracted at summit, rounded and dilated at base. The last whorl is very large, completely detached from the spire

Spire (mollusc)

A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...

 by the deeply incised sutural slit. The aperture

Aperture (mollusc)

The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....

 is very large, angled above, rounded below. The lip is arcuate, simple and acute. The columellar margin is with a very thin film of callus above, concave below, acute, forming an open spiral through which the interior of the whorls

Whorl (mollusc)

A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...

may be seen from the base. Color is uniform glassy white, with a thin transparent and shining, very light yellow cuticle.

The height of the shell is 12 mm. The width of the shell is 9 mm.

Further reading

• Bogi C., Coppini M. & Margelli A. (1984). "Contribution to the knowledge of North Tyrrhenean Malacofauna". La Conchiglia 186-7: 3-7.
• Thibaut T. & Meinesz A. (May 2000). "Are the Mediterranean ascoglossan molluscs Oxynoe olivacea and Lobiger serradifalci suitable agents for a biological control against the invading tropical alga Caulerpa taxifolia? Les mollusques ascoglosses de Méditerranée Oxynoe olivacea et Lobiger serradifalci peuvent-ils être utilisés comme agents de lutte biologique contre l’algue tropicale envahissante Caulerpa taxifolia ?". Comptes Rendus de l’Académie des Sciences - Series III - Sciences de la Vie 323(5): 477-488.

External links

• http://www.seaslugforum.net/factsheet/oxynoliv