| California aglaja | |
|---|---|
| |
| From Santa Barbara, California | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Order: | Cephalaspidea |
| Family: | Aglajidae |
| Genus: | Navanax |
| Species: | N. inermis |
| Binomial name | |
| Navanax inermis (Cooper, 1863) | |
| 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. Yellow or orange streaks and blue dots are visible on the margins. It has two large parapodial folds that run the length of either side of the body, and almost touch at the midsection. This species possesses a small internal shell. Individuals are typically between 2.5 and 10 inches in length.
Navanax inermis does not possess a radula or organs associated with vision.
Distribution and habitat
This species occurs in the eastern Pacific Ocean and Gulf of California. Its range is from Monterey, California to Baja California.
Navanax inermis can commonly be found on rocky intertidal regions and subtidal mudflats.
Ecology
Diet
Navanax inermis is a voracious carnivorous predator. Common prey items include other sea slugs, like bubble snails and nudibranchs, and small fish. As N. inermis lacks visual perception, it finds prey by using its chemoreceptors to follow the slime trails of other organisms.
Reproduction
Navanax inermis is a simultaneous hermaphrodite. Copulation can occur in groups, commonly referred to as chains, of up to four individuals. In the southern portion of its range, N. inermis spawns year round, producing upwards of 800,000 eggs at a time. After 7 to 19 days of development, embryos are released and live as plankton.
Locomotion
Navanax inermis slides over surfaces with the help of a mucopolysaccharide slime trail.
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.
References
- ^ 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.
{{cite book}}: CS1 maint: multiple names: authors list (link) - ^ 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.
{{cite book}}: CS1 maint: multiple names: authors list (link) - ^ Sleeper, Howard L.; Paul, Valerie J.; Fenical, William (January 1980). "Alarm pheromones from the marine opisthobranch Navanax inermis". Journal of Chemical Ecology. 6 (1): 57–70. Bibcode:1980JCEco...6...57S. doi:10.1007/bf00987527. ISSN 0098-0331.
- ^ Paine, Robert T. (1965). "Natural History, Limiting Factors and Energetics of the Opisthobranch Navanax Inermis". Ecology. 46 (5): 603–619. Bibcode:1965Ecol...46..603P. doi:10.2307/1935000. JSTOR 1935000.
- "The Sea Slug Forum - Navanax inermis". www.seaslugforum.net. 2010-07-15. Retrieved 2018-08-12.
- ^ 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.
Media related to Navanax inermis at Wikimedia Commons
| Taxon identifiers | |
|---|---|
| Navanax inermis | |