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 that over evolutionary time have either completely lost their shells, or have seemingly lost their shells due to having a greatly reduced or internal shell. The name "sea slug" is most often applied to nudibranchs, as well as to a paraphyletic set of other marine gastropods without obvious shells.
Navanax inermis, common name the California aglaja, is a large species of predatory sea slug, a marine opisthobranch gastropod mollusk in the family Aglajidae. Navanax is not a nudibranch, even though it somewhat resembles one; it belongs to a more ancient lineage of opisthobranchs called the cephalaspideans or head shield slugs and snails.
Penis fencing is a mating behavior engaged in by many species of flatworm, such as Pseudobiceros hancockanus. Species which engage in the practice are hermaphroditic; each individual has both egg-producing ovaries and sperm-producing testes.
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.
Chelidonura hirundinina is a species of small and colorful aglajid sea slug, a shell-less opisthobranch gastropod mollusk in the family Aglajidae.
A love dart is a sharp, calcareous or chitinous dart which some hermaphroditic land snails and slugs create. Love darts are both formed and stored internally in a dart sac. These darts are made in sexually mature animals only, and are used as part of the sequence of events during courtship, before actual mating takes place. Darts are quite large compared to the size of the animal: in the case of the semi-slug genus Parmarion, the length of a dart can be up to one fifth that of the semi-slug's foot.
Elysia timida is a species of sacoglossan sea slug, a marine opisthobranch gastropod mollusk. Found in the Mediterranean and nearby parts of the Atlantic, it is herbivorous, feeding on various algae in shallow water.
Chelidonura pallida is a species of sea slug, or "headshield slug", a marine opisthobranch gastropod mollusk in the family Aglajidae.
Chelidonura is a genus of small, sometimes colorful, sea slugs. These are headshield slugs or cephalaspideans, marine opisthobranch gastropod mollusks in the family Aglajidae.
Mariaglaja inornata, also called the inornate headshield slug, is a species of sea slug or headshield slug, a marine opisthobranch gastropod mollusc in the family Aglajidae.
Chelidonura punctata is a species of sea slug, or "headshield slug", a marine opisthobranch gastropod mollusk in the family Aglajidae.
Chelidonura amoena is a species of sea slug, or "headshield slug", a marine opisthobranch gastropod mollusk in the family Aglajidae.
William B. "Bill" Rudman is a malacologist from New Zealand and Australia. In particular he studies sea slugs, opisthobranch gastropod molluscs, and has named many species of nudibranchs.
Chromodoris orientalis is a species of colourful sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Chromodorididae. Sea slugs are generally very beautifully colored organisms with intense patterns and ranging in sizes. The Chromodoris orientalis specifically is a white sea slug with black spots in no particular pattern with a yellow, orange, or brown in color ring around its whole body and on its gills. There is much discussion on where it is found, what it eats, how it defends itself without a shell, and its reproduction methods. This is all sought after information because there is not much known about these animals.
Siphopteron quadrispinosum is a species of small sea slug, a marine opisthobranch gastropod mollusc in the order Cephalaspidea, the headshield slugs. This slug is a simultaneous hermaphrodite.
Chelidonura electra is a species of sea slug, a "headshield slug", a marine opisthobranch gastropod mollusk in the family Aglajidae. The species name comes from the daughter of Agamemnon, Electra, and the Greek goddess of the same name, meaning "shining", with reference to the brilliance of this slug.
The mating of gastropods is a vast and varied topic, because the taxonomic class Gastropoda is very large and diverse, a group comprising sea snails and sea slugs, freshwater snails and land snails and slugs. Gastropods are second only to the class Insecta in terms of total number of species. Some gastropods have separate sexes, others are hermaphroditic. Some hermaphroditic groups have simultaneous hermaphroditism, whereas some sequential hermaphroditism. In addition, numerous very different mating strategies are used within different taxa.
Biuve fulvipunctata, the white-speckled headshield slug, is a species of sea slug or headshield slug, a marine opisthobranch gastropod mollusc in the family Aglajidae. This species is widespread in the Indian and Pacific Oceans but has invaded the Mediterranean Sea since 1961, despite apparently being absent from the Red Sea until recorded there in the 21st century. It is the only species in the monotypic genus Biuve.
Phestilla minor is a species of sea slug in the Trichechidae family. It is a type of aeolid nudibranch under the Aeolidina suborder. Phestilla minor is a benthic sea slug that is a very small, slow-moving organism found in marine habitats all over the world.
Tubulophilinopsis gardineri, the Gardiner’s philinopsis, or Gardiner's headshield slug is a species of sea slug, a shell-less opisthobranch gastropod mollusc in the family Aglajidae. It is native to the Indo-Pacific region.
