Ophioplocus esmarki
| Ophioplocus esmarki | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Ophiuroidea |
| Order: | Amphilepidida |
| Family: | Hemieuryalidae |
| Genus: | Ophioplocus |
| Species: | O. esmarki
|
| Binomial name | |
| Ophioplocus esmarki Lyman, 1874[1]
| |
Ophioplocus esmarki, commonly known as Esmark's brittle star or the smooth brittle star, is a species of brittle star in the family Hemieuryalidae. It can be found from the low intertidal to a depth of 70 m, from Northern California to Baja California.[2][3] This is one of the few brittle star species that is visible during daylight hours.[4]
Description
Esmark's brittle star is typically a gray-brown color. It has a round central disc, up to 22 mm in diameter, and five arms, up to 60 mm, each with very short spines.[4]
Natural history
Ophioplocus esmarki follows pattern of abbreviated development in which non-feeding larvae called vitellaria spend only a few days as free-swimming plankton before metamorphosing into a juveniles. Adults brood their embryos, vitellaria, and juveniles inside their genital bursae (pouches) located in the central disc.[5] One study estimates that it takes 9 to 11 years for this species to reach 50% of its final body size.[6]
References
- ^ Stöhr, Sabine (2007). "Ophioplocus esmarki Lyman, 1874". WoRMS. World Register of Marine Species. Retrieved February 5, 2026.
- ^ Presiado, Rhea Suzanne (2005). Biogeography of the brittle star Ophioplocus esmarki (Echinodermata: Ophiuroidea). University of California, Davis.
- ^ "Ophioplocus esmarki". Reeflex. Retrieved February 5, 2026.
- ^ a b Watanabe, James (2021). "Class Ophiuroidea". Stanford SeaNet. Retrieved February 5, 2026.
- ^ Sweet, Hyla C; Doolin, Megan C; Yanowiak, Chelsea N; Coots, Ashley D; Freyn, Alec W; Armstrong, Jane M; Spiecker, Barbara J (2019). "Abbreviated development of the brooding brittle star Ophioplocus esmarki". The Biological Bulletin. 236 (2): 75--87 – via The University of Chicago Press Online.
- ^ Medeiros-Bergen, Dorothy E; Ebert, Thomas A (1995). "Growth, fecundity and mortality rates of two intertidal brittlestars (Echinodermata: Ophiuroidea) with contrasting modes of development" (PDF). Journal of Experimental Marine Biology and Ecology. 189 (1--2): 47--64 – via Elsevier.