''Alderia willowi'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

sea slug Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatures known as sea slugs are gastropods, i.e. they are sea snails (marine gastropod mollusks) that over evolutionary t ...

, a

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

in the family

Limapontiidae Limapontiidae is a taxonomic family of small to minute sacoglossan sea slugs. These are marine opisthobranch gastropod mollusks.Bouchet, P.; Gofas, S. (2011). Limapontiidae. Accessed through: World Register of Marine Species at http://www.marines ...

. It is a

sacoglossa Sacoglossa, commonly known as the sacoglossans or the "solar-powered sea slugs", are a superorder of small sea slugs and sea snails, marine gastropod mollusks that belong to the clade Heterobranchia. Sacoglossans live by ingesting the cellular ...

n. This species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

. It was previously thought to be ''

Alderia modesta ''Alderia modesta'' is a species of sea slug, a marine (ocean), marine gastropod mollusc in the family Limapontiidae. It is found in estuarine habitats and saltmarshes on either side of the North Atlantic and the North Pacific Oceans. Descripti ...

'', but there turned out to be a

cryptic species In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

pair. This species is poecilogonous, in other words it has variable larval development modes. The slug was discovered by a team led by Patrick Krug of

California State University, Los Angeles California State University, Los Angeles (Cal State LA) is a public university in Los Angeles, California. It is part of the 23-campus California State University (CSU) system. Cal State LA offers 142 bachelor's degrees, 122 master's degrees, ...

. The species is named after Krug's grandmother, and after the

fictional character In fiction, a character (or speaker, in poetry) is a person or other being in a narrative (such as a novel, play, radio or television series, music, film, or video game). The character may be entirely fictional or based on a real-life person, ...

Willow Rosenberg Willow Rosenberg is a fictional character created for the fantasy television series ''Buffy the Vampire Slayer'' (1997–2003). She was developed by Joss Whedon and portrayed throughout the TV series by Alyson Hannigan. Willow plays an integral ...

from ''

Buffy the Vampire Slayer ''Buffy the Vampire Slayer'' is an American supernatural fiction, supernatural drama television series created by writer and director Joss Whedon. It is based on the Buffy the Vampire Slayer (film), 1992 film of the same name, also written by W ...

television series A television show – or simply TV show – is any content produced for viewing on a television set which can be broadcast via over-the-air, satellite television, satellite, or cable television, cable, excluding breaking news, television adverti ...

, because the variable reproductive modes of the sea slug are reminiscent of the switch in sexual orientation that the character Willow underwent in

season 4 Season 4 may refer to: * "Season 4" (''30 Rock'' episode), an episode of ''30 Rock'' See also * * Season One (disambiguation) Season One may refer to: Albums * ''Season One'' (Suburban Legends album), 2004 * ''Season One'' (All Sons & Daughte ...

of the show.

References

Limapontiidae Gastropods described in 2007 {{Limapontiidae-stub