Scientific name Onchidiidae Rank Family | ||
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Superfamily OnchidioideaRafinesque, 1815 Lower classifications | ||
Onchidium sp slug onchidiidae oriental mindoro philippines
Onchidiidae are a family of small, air-breathing sea (and land) slugs. They are shell-less marine (except of 5 species) pulmonate gastropod molluscs. Onchidiidae is the only family within the superfamily Onchidioidea.
Contents
- Onchidium sp slug onchidiidae oriental mindoro philippines
- Onchidiidae platevindex spec
- Anatomy
- Genetics
- Habitat
- Life habits
- Genera
- References
These animals are quite unusual in that they are emphatically not opisthobranchs with gills, as are almost all of the sea slugs. Instead these creatures are pulmonates. They are more closely related to air-breathing land and freshwater snails and slugs than they are to most other sea snails and sea slugs.
This family has no subfamilies (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).
There are 143 species names within the Onchidiidae, but a detailed revision has not been made yet, because there is no living malacologist expert enough on the whole group to properly identify them.
Onchidiidae platevindex spec
Anatomy
Adult onchidiids lack a shell, although a shell and operculum is present at the larval stage. The mantle cavity is reduced to the point of absence, correlating with a loss of gills, raphes, and other characters usually found in the mantle cavity. The organism is completely detorted.
Slugs in this family make and use love darts made of chitin.
Genetics
In this family, the number of haploid chromosomes lies between 16 and 20 (according to the values in this table).
Habitat
Most of the species in this family are marine and are found in the intertidal zone on rocky coasts. However, two species live in brackish water and three are terrestrial.
Onchidium typhae (India) and Labbella ajuthiae (synonym in literature: Elophilus ajuthiae) (Thailand) are the only two species in the Onchidiidae that live in brackish water. They can also live in freshwater.
Oncis ponsonbyi (synonym in literature: Platevindex ponsonbyi) and Semperoncis montana (synonym in literature: Platevindex apoikistes and Semperella montana) are the only terrestrial species in the Onchidiidae. They live in high-elevation rainforests in Borneo and the Philippines.
Life habits
All these slugs breathe air. The marine ones breathe and move around and feed during low tide, when the water recedes and the slugs are exposed to the air.
Genera
Genera in the family Onchidiidae include: