Biology:Navanax inermis
| California aglaja | |
|---|---|
| |
| From Santa Barbara, California | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Heterobranchia |
| Order: | Cephalaspidea |
| Family: | Aglajidae |
| Genus: | Navanax |
| Species: | N. inermis
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| Binomial name | |
| Navanax inermis (Cooper, 1863)
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| Synonyms | |
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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.
Description
The body of N. inermis can be tan, black, or purple, with yellowish streaks.[1] Yellow or orange streaks and blue dots are visible on the margins.[1] It has two large parapodial folds that run the length of either side of the body, and almost touch at the midsection.[1] This species possesses a small internal shell.[1][2] Individuals are typically between 2.5 and 10 inches in length.[1]
Navanax inermis does not possess a radula or organs associated with vision.[1][3]
Distribution and habitat
This species occurs in the eastern Pacific Ocean and Gulf of California. Its range is from Monterey, California to Baja California.[4]
Navanax inermis can commonly be found on rocky intertidal regions and subtidal mudflats.[1][2][3]
Ecology
Diet
Navanax inermis is a voracious carnivorous predator.[2] Common prey items include other sea slugs, like bubble snails and nudibranchs, and small fish.[4][5] As N. inermis lacks visual perception, it finds prey by using its chemoreceptors to follow the slime trails of other organisms.[1][3][4]
Reproduction
Navanax inermis is a simultaneous hermaphrodite.[6] Copulation can occur in groups, commonly referred to as chains, of up to four individuals.[6] In the southern portion of its range, N. inermis spawns year round, producing upwards of 800,000 eggs at a time.[4] After 7 to 19 days of development, embryos are released and live as plankton.[4]
Locomotion
Navanax inermis slides over surfaces with the help of a mucopolysaccharide slime trail.[3]
Defense
When disturbed, N. inermis secretes a bright yellow substance into its slime trail, which can persist for several hours. This secretion causes some other organisms to break pursuit of the slug.[3]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 N., Kerstitch, Alex (1989). Sea of Cortez marine invertebrates : a guide for the Pacific Coast, Mexico to Ecuador (1st ed.). Monterey, Calif.: Sea Challengers. ISBN 978-0930118143. OCLC 18520858.
- ↑ 2.0 2.1 2.2 C., Brusca, Richard (1980). Common intertidal invertebrates of the Gulf of California (Rev. and expanded, 2nd ed.). Tucson: University of Arizona Press. ISBN 978-0816506828. OCLC 5310036. https://archive.org/details/commonintertidal00brus.
- ↑ 3.0 3.1 3.2 3.3 3.4 Sleeper, Howard L.; Paul, Valerie J.; Fenical, William (January 1980). "Alarm pheromones from the marine opisthobranch Navanax inermis" (in en). Journal of Chemical Ecology 6 (1): 57–70. doi:10.1007/bf00987527. ISSN 0098-0331.
- ↑ 4.0 4.1 4.2 4.3 4.4 Paine, Robert T. (1965). "Natural History, Limiting Factors and Energetics of the Opisthobranch Navanax Inermis". Ecology 46 (5): 603–619. doi:10.2307/1935000.
- ↑ "The Sea Slug Forum - Navanax inermis" (in en). 2010-07-15. http://www.seaslugforum.net/find/navainer.
- ↑ 6.0 6.1 Leonard, Janet L.; Lukowiak, Ken (1985). "Courtship, copulation, and sperm trading in the sea slug, Navanax inermis (Opisthobranchia: Cephalaspidea)". Canadian Journal of Zoology 63 (12): 2719–2729. doi:10.1139/z85-406. ISSN 0008-4301.
Wikidata ☰ Q3173679 entry
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