Parapinnixa affinis

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Parapinnixa affinis
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Malacostraca
Order: Decapoda
Suborder: Pleocyemata
Infraorder: Brachyura
Family: Parapinnixidae
Genus: Parapinnixa
Species:
P. affinis
Binomial name
Parapinnixa affinis
Holmes, 1900 [2]

Parapinnixa affinis, the California Bay pea crab, is a species of pinnotherid crab endemic to Southern California.[1] It is a small crab that lives commensally in the tube of a tube-dwelling worm. It was one of the first marine crustaceans to be included on the IUCN Red List in 1996.

Description

Parapinnixa affinis is similar to other pea crabs of the genus Parapinnixa, especially P. nitida. It differs from P. nitida in the proportions of its carapace, which is more than twice as wide as long in P. nitida but less than twice as wide as long in P. affinis.[3] The carapace is approximately 4.5 mm × 2.5 mm (0.177 in × 0.098 in) wide, with a maximum of 6.0 mm × 3.6 mm (0.24 in × 0.14 in).[4] The carapace is usually "light amber mottled with dark ochre",[4] but 5% of crabs are albino.[4]

Distribution

Parapinnixa affinis appears to be

Anaheim Landing, Newport Bay and San Diego.[4] It was once recorded from Siberia, but this record is doubtful.[5]

Conservation and ecology

Parapinnixa affinis was one of only two marine crustaceans to be included on the IUCN's list of endangered species in 1996, the other being the coconut crab.[6] Many others have been added later.

It lives

polychaete worms Terebella californica and Loimia.[7] A bryozoan from the family Vesiculariidae is sometimes found on the legs of P. affinis.[4]

Taxonomy

Parapinnixa affinis was

type locality, which has been made unsuitable by the accumulation of "harbor refuse and oil".[4] No further specimens were collected for over thirty years, until one was collected in 1930, and Steve Glassell collected specimens including an allotype in 1932.[4]

References

  1. ^
    doi:10.2305/IUCN.UK.1996.RLTS.T16185A5504008.en
    . Retrieved 17 November 2021.
  2. ^ "Parapinnixa affinis Holmes, 1900". Integrated Taxonomic Information System. Retrieved February 23, 2011.
  3. ^ a b Samuel J. Holmes (1900). "Synopsis of California stalk-eyed Crustacea". Occasional Papers of the California Academy of Sciences. 7 (27): 1–260.
  4. ^ a b c d e f g Steve A. Glassell (1933). "Notes on Parapinnixa affinis Holmes and its allies". Transactions of the San Diego Natural History Society. 7: 319–330.
  5. doi:10.2988/0006-324x(2005)118[543:ansopd]2.0.co;2
    .
  6. ^ Jonathan Baillie (1996). "Analysis". 1996 IUCN Red List of Threatened Animals. International Union for Conservation of Nature. Archived from the original on 2007-12-14.
  7. ISBN 978-0-520-23939-5
    .
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