Phidiana hiltoni 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 sea slug, an aeolid 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 shell-less 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 Aeolidiidae

Aeolidiidae

Aeolidiidae, the aeolid nudibranchs, are a family of Nudibranchs. Many feed on hydroids and thus have highly serrated radular teeth.- Genera :Genera and species within the Aeolidiidae include:* Aeolidia Cuvier, 1797 - type genus...

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Distribution

This species has a rather narrow range of distribution, being found from the central California coast to Baja California, Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

, and it is also found in the Gulf of Mexico

Gulf of Mexico

The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...

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Description

This nudibranch grows to 50 mm, or a little more than 2 inches in length. The reddish or brownish line across its head is almost always present, and is very characteristic of the species.

This species can be confused with Hermissenda crassicornis

Hermissenda crassicornis

Hermissenda crassicornis is a species of small, brightly-colored, sea slug or nudibranch, a marine gastropod mollusk in the family Glaucidae.This species is also commonly known as the "opalescent sea slug."-Distribution:...

, which is superficially similar in appearance.

Life habits

This aolid nudibranch species is considered to be rather aggressive, often biting and fighting with other nudibranchs, including members of its own species.

External links

• Sea Slug Forum factsheet: http://www.seaslugforum.net/showall.cfm?base=phidhilt
• Slug Site: http://slugsite.us/bow/nudiwkps/nudiwk25.html