Opimia

This article is about the genus of copepods. For the ancient Roman priestess known as Opimia, see Vestal Virgins.

Opimia
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Copepoda
Order:	Siphonostomatoida
Family:	Sphyriidae
Genus:	Opimia Wilson, 1908
Species:	O. exilis
Binomial name
Opimia exilis Wilson, 1908

Opimia is a monotypic genus of marine copepods in the family Sphyriidae. Its sole species, Opimia exilis, is a parasite of school sharks and dusky sharks.

Taxonomy and history

The genus Opimia and its sole species Opimia exilis were described by Charles Branch Wilson in 1908. ^[1] Wilson inititally placed Opimia in the family Lernaeidae, but would later find in a 1915 taxonomic revision that it and several other genera should be excluded from Lernaeidae on the basis of morphological characteristics. In 1919 Wilson would erect the family Sphyriidae to include Opimia and other parasitic copepod genera previously placed in Lernaeidae. ^{[2] [3]} The generic name Opimia is derived from the Vestal Virgin of the same name, who is said to have been buried alive for breaking her vow, while the specific epithet exilis means "slender". Wilson described the genus and species based on two female specimens collected from school sharks (Galeorhinus galeus) near La Jolla, California. ^[2]

Distribution and habitat

Opimia exilis has been collected from the waters off Southern California and from the Gulf of Mexico. ^{[2] [4] [5] : 21, 24}

Description

Adult female Opimia exilis are slender and elongated, lacking any external segmentation. The body can be divided into a rounded cephalothorax, a neck, and a narrow trunk bearing the genitals and a pair of posterior processes. The cephalothorax is swollen into a spherical shape and lacks any lobes or processes but has retained a single pair of rudimentary legs. The neck is cylindrical, comprising about two thirds of the total body length, and smooth except some wrinkles at the base where it joins the trunk. The trunk is longer than it is wide, with a pair of slender cylindrical processes protruding from the posterior end. The abdomen is small and rudimentary. ^{[2] [3]}

The male of this species is unknown. ^{[2] [3]}

Ecology

Adult female Opimia exilis are parasites of school sharks (Galeorhinus galeus) and dusky sharks (Carcharhinus obscurus), attaching to the mouth and gills. ^{[4] [5] : 21, 24, 476}

References

1. Walter TC, Boxshall G (eds.). "Opimia Wilson C.B., 1908". World of Copepods Database. World Register of Marine Species . Retrieved 7 May 2025.
2. Wilson, Charles Branch (1908). "North American parasitic copepods: A list of those found upon the fishes of the Pacific coast, with descriptions of new genera and species". Proceedings of the United States National Museum . 35 (1652): 459–460. doi: 10.5479/si.00963801.35-1652.431 .
3. Wilson, Charles Branch (1919). "North American parasitic copepods belonging to the new family Sphyriidae". Proceedings of the United States National Museum . 55 (2286): 589–590. doi: 10.5479/si.00963801.55-2286.549 .
4. Bere, Ruby (1936). "Parasitic Copepods from Gulf of Mexico Fish". The American Midland Naturalist . 17 (3): 577–625. doi:10.2307/2419936. JSTOR   2419936.
5. Love, Milton S.; Moser, Mike (December 1983). "A Checklist of Parasites of California, Oregon, and Washington Marine and Estuarine Fishes". NOAA Technical Report NMFS SSRF (777). United States Department of Commerce, National Oceanic and Atmospheric Administration, and National Marine Fisheries Service. ISSN   0094-4580. LCCN   83644784 – via Biodiversity Heritage Library.