| Bursovaginoidea | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Gnathostomulida |
| Order: | Bursovaginoidea |
| Suborders | |
Also see text | |
Bursovaginoidea is one of the two orders in the phylum Gnathostomulida.[1]
Appearance and anatomy
Bursovaginoids are rather small, ranging from a half of a millimeter to a full millimeter in length.[2] Many species in the order Bursovaginoidea have a narrow neck, making their head stand out more than other bursovagionoids and all filospermoids.[3]
Bursovaginoids, unlike filospermoids, have paired sensory organs and a penis.[4] Also, all species in Bursovaginoidea have a sperm-storage organ called a bursa. In suborder Scleroperalia, the bursa is cuticular, while in Conophoralia it is not. Species in order Conophoralia tend to have larger sperm than those in Sceloperalia.[2]
Distribution
Sightings of bursovaginoids have been reported in various parts of the world, including England and the north-western and south-eastern parts of the United States. Bursovaginoids mostly live in oceans near the coasts, in depths of under 500 meters (1650 feet), most commonly around 300.[5]
Families
The order Bursovaginoidea contains 73 - 75 species and 24 genera in the following 10 families:[6][7]
- Suborder Conophoralia
- Austrognathiidae (27 species in 4 genera)
- Suborder Scleroperalia
- Agnathiellidae (3 species in 2 genera)
- Clausognathiidae (1 species in 1 genus)
- Gnathostomariidae (1 species in 1 genus)
- Gnathostomulidae (23 - 25 species in 5 genera)
- Mesognathariidae (6 species in 3 genera)
- Onychognathiidae (9 species in 5 genera)
- Paucidentulidae (1 species in 1 genus)
- Problognathiidae (1 species in 1 genus)
- Rastrognathiidae (1 species in 1 genus)
References
- ↑ "Order Summary for Bursovaginoidea". Sea Life Base. Retrieved 7 April 2018.
- 1 2 Light, Sol Felty (2007). The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon. University of California Press. p. 276. ISBN 978-0520239395. Retrieved 7 April 2018.
- ↑ Barnes, Robert D. (1982). Invertebrate Zoology. Philadelphia, PA: Holt-Saunders International. pp. 311–312. ISBN 0-03-056747-5.
- ↑ Barnes, R.F.K. et al. (2001). The Invertebrates: A Synthesis. Oxford: Blackwell Science.
- ↑ "Bursovaginoidea". Ocean Biogeographic Information System. Retrieved 7 April 2018.
- ↑ Sterrer, W. (2006). "Bursovaginoidea". www.marinespecies.org. Retrieved 21 January 2018.
- ↑ Integrated Taxonomic Information System. "ITIS Standard Report Page: Bursovaginoidea". www.itis.gov. Retrieved 29 January 2018.