Risbecia tryoni
Encyclopedia
Risbecia tryoni is a species
of sea slug
, a dorid nudibranch
, a marine
gastropod mollusk in the family Chromodorididae
.
to the Philippines
.
are covered in purple spots ringed with white or light-brown. The gills are typically translucent white or light-brown and the rhinophores are brown to dark-brown and covered in circular white lines. It has a thin blue or purple line on the mantle edge. There is some colour variation between individuals.
Risbecia tryoni is similar in appearance to Chromodoris kuniei
and Chromodoris leopardus
, although lacks the wide purple mantle edge line present in those species.
Sea slugs in the genus Risbecia, including Risbecia tyroni, are known to exihibit trailing behaviour where up to four animals will follow one another very closely, often touching. It is not known what causes this behaviour.
Risbecia tryoni reaches at least 60 mm in length.
, Risbecia tyroni feeds on sponges and have been seen feeding on sponges from the genus Dysidea. When feeding they are sometimes accompanied by a species of shrimp, Periclimenes imperator
, in an apparent form of Commensalism
.
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 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 dorid 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...
, 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 Chromodorididae
Chromodorididae
Chromodorididae are a taxonomic family of medium-sized to large, colorful, sea slugs; dorid nudibranchs in the superfamily Doridoidea. These are marine gastropod mollusks....
.
Distribution
This species occurs in the tropical Western Pacific Ocean from AustraliaAustralia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
to the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
.
Description
Risbecia tryoni has a brown body and white foot. The body and upper dorsumDorsum (anatomy)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
are covered in purple spots ringed with white or light-brown. The gills are typically translucent white or light-brown and the rhinophores are brown to dark-brown and covered in circular white lines. It has a thin blue or purple line on the mantle edge. There is some colour variation between individuals.
Risbecia tryoni is similar in appearance to Chromodoris kuniei
Chromodoris kuniei
Chromodoris kuniei is a species of very colorful sea slug, a dorid nudibranch, a marine gastropod mollusk in the family Chromodorididae. There is one subspecies : Chromodoris kuniei ransoni- Habitat :...
and Chromodoris leopardus
Chromodoris leopardus
Chromodoris leopardus is a species of colorful sea slug, a dorid nudibranch, a marine gastropod mollusk in the family Chromodorididae....
, although lacks the wide purple mantle edge line present in those species.
Sea slugs in the genus Risbecia, including Risbecia tyroni, are known to exihibit trailing behaviour where up to four animals will follow one another very closely, often touching. It is not known what causes this behaviour.
Risbecia tryoni reaches at least 60 mm in length.
Ecology
Like many slugs in the family ChromodorididaeChromodorididae
Chromodorididae are a taxonomic family of medium-sized to large, colorful, sea slugs; dorid nudibranchs in the superfamily Doridoidea. These are marine gastropod mollusks....
, Risbecia tyroni feeds on sponges and have been seen feeding on sponges from the genus Dysidea. When feeding they are sometimes accompanied by a species of shrimp, Periclimenes imperator
Periclimenes imperator
Periclimenes imperator is a species of shrimp with a wide distribution across the Indo-Pacific. It lives commensally on a number of hosts, including the sea slug Hexabranchus....
, in an apparent form of Commensalism
Commensalism
In ecology, commensalism is a class of relationship between two organisms where one organism benefits but the other is neutral...
.