Navanax inermis 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 predatory 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...

 opisthobranch gastropod mollusk in the family Aglajidae

Aglajidae

Aglajidae is a family of often colorful, medium-sized, sea slugs, marine opisthobranch gastropod mollusks. These are not nudibranchs; instead they are headshield slugs, in the clade Cephalaspidea.-Genera:...

 and the order Cephalaspidea

Cephalaspidea

The suborder Cephalaspidea, also known as the headshield slugs and bubble snails, is a clade of sea slugs and bubble snails, marine gastropod mollusks within the larger clade Euopisthobranchia....

, the headshield slugs and bubble snails.
It has been suggested that this species should be moved to the genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Aglaja

Aglaja

Aglaja is a dance theater from Bruges, Belgium.Founded in the late 1960s by the visionary choreographer and teacher Jan Dewulf, it is still one of Bruges most important cultural ambassadors...

, but the name Navanax is still used in many of the popular works on mollusks.

Navanax 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...

, even though it somewhat resembles one; it belongs to a more ancient group of opisthobranchs.

Distribution

This species occurs in the eastern Pacific Ocean

Pacific Ocean

The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

. Its range is from Bolinas Lagoon

Bolinas Lagoon

Bolinas Lagoon is a tidal estuary, approximately in area, located at in the West Marin region of Marin County, California, United States. It is a part of the Gulf of the Farallones National Marine Sanctuary. The lagoon is a back bay of Bolinas Bay on the Pacific coast approximately 15 mi ...

, California, in the north, to Laguna Manuela and to Jalisco

Jalisco

Jalisco officially Estado Libre y Soberano de Jalisco is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is located in Western Mexico and divided in 125 municipalities and its capital city is Guadalajara.It is one of the more important states...

 in 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...

, in the south, including the Gulf of California

Gulf of California

The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...

.

Life habits

Navanax inermis is a voracious predator, feeding on various sea slugs and bubble snails of the order Cephalaspidea, as well as nudibranchs such as 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:...

, Polycera atra, and Dirona picta. It uses chemoreceptors to track the slime trails of prey, and of potential mates.

Like all other Opisthobranchs, it is hermaphroditic

Hermaphrodite

In biology, a hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes.Many taxonomic groups of animals do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which both...

.