Clausidium vancouverense

Clausidium vancouverense
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Crustacea
Class:	Maxillopoda
Subclass:	Copepoda
Order:	Poecilostomatoida
Family:	Clausidiidae
Genus:	Clausidium
Species:	C. vancouverense
Binomial name
Clausidium vancouverense Haddon, 1912

Clausidium vancouverense, the red copepod, is a symbiont of the ghost shrimp Neotrypaea californiensis.^[1] It is one of six species in the genus Clausidium and is found with its host in the Pacific Ocean from Alaska to Baja California.^[2]

Description

Females range in length from 1.086–1.222 millimetres (0.043–0.048 in). The female is larger than the male, and a female sometimes carries a male attached to her dorsal thorax.^[3]

Several features separate this copepod from other species in its genus. These include the blade-like seta on the first leg and the small lateral hairs on the setae of the fifth leg on females. In males, the structure of the maxilliped is unique.

Ecology

Copepod distribution of a similar species Clausidium dissimile on ghost shrimp were positively correlated to the host's body size,^[4] but host sex did not affect distribution.^[5] C. vancouverense sticks to the branchial cavity of its host via suckers.

References

1. ^ A. D. Humes (1949). "A new copepod (Cyclopoida: Clausidiidae) parasitic on mud shrimps in Louisiana". Transactions of the American Microscopical Society 68: 93–103. PMID 18153316. http://www.jstor.org/stable/3223256. 
2. ^ "Online Field Guide". Monterey Bay Aquarium. http://www.mbayaq.org/efc/living_species/default.asp?hOri=0&hab=3&inhab=456. Retrieved May 23, 2008. 
3. ^ Charles Branch Wilson (1935). "Parasitic copepods from the Pacific coast". American Midland Naturalist 16: 776–797. http://www.jstor.org/stable/2420107. 
4. ^ Sandra L. Marin & Mario George-Nascimento (1975). "Tamaño corporal y hábitat del nape Callianassa garthi Retamal, 1975 (Crustacea: Thalassinidea) como factores que afectan la distribución y abundancia del copépodo Clausidium sp. (Cyclopoida) [Host body size and habitat as factors affecting the distribution and abundance of the copepod Clausidium sp. (Cyclopoida), ectosymbiont of the ghost shrimp Callianassa garthi Retamal, 1975 (Crustacea: Thalassinidea)]" (in Spanish) (PDF). Revista Chilena de Historia Natural 66: 427–437. http://rchn.biologiachile.cl/pdfs/1993/4/Marin_&_George-Nascimento_1993.pdf. 
5. ^ J. L. Corsetti & K. M. Strasser (2003). "Host selection of the symbiotic copepod Clausidium dissimile in two sympatric populations of ghost shrimp". Marine Ecology Progress Series 256: 151–159.