Neotrypaea californiensis

Neotrypaea californiensis
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Crustacea
Class:	Malacostraca
Order:	Decapoda
Infraorder:	Axiidea
Family:	Callianassidae
Genus:	Neotrypaea
Species:	N. californiensis
Binomial name
Neotrypaea californiensis (Dana, 1854)
Synonyms [1][2]
Callianassa californiensis Dana, 1854 Callianassa occidentalis Stimpson, 1856

Neotrypaea californiensis (formerly Callianassa californiensis), the Bay ghost shrimp, is a species of ghost shrimp that lives on the Pacific coast of North America. It is a pale animal which grows to a length of 11.5 cm (4.5 in). One claw is bigger than the other, especially in males, and the enlarged claw is thought to have a function in mating. N. californiensis is a deposit feeder that lives in extensive burrow systems, and is responsible for high rates of bioturbation. It adversely affects oyster farms, and its numbers are controlled in some places by the application of pesticides. It carries out an important role in the ecosystem, and is used by fishermen as bait.

Description and life cycle

Neotrypaea californiensis reaches a length of 11.5 centimetres (4.5 in).^[2] The body is creamy white, with patches of pale colour (pink, yellow or orange) on the appendages, and a pink abdomen.^[3]

Adult N. californiensis have one claw larger than the other, and in the males, the "master claw" can make up as much as 25% of the animal's mass – compared to only 10% in females – with the minor claw making up around 3% of the total body mass in both sexes.^[4] The enlarged claw is equally likely to be on the right side or the left side.^[4] The male's larger claw is thought to be used in agonistic encounters or during mating, and may be the result of sexual selection.^[4]

Eggs are laid in spring or early summer, and the larvae hatch in summer, living as plankton. They settle to the sea floor again as post-larvae in the late summer and fall.^[5]

Taxonomy

N. californiensis was originally described in 1854 by James Dwight Dana as a member of the genus Callianassa, giving the type locality as "California";^[3] the material Dana studied was probably collected from San Francisco Bay or Monterey,^[3] but the original specimens have since been lost.^[2] In 1991, Raymond Manning and Darryl Felder transferred the three species in that genus that come from California and Oregon into the new genus Neotrypaea.^[3] N. californiensis is distinguished from the other two species of Neotrypaea by the lack of a rostrum (which is present in Neotrypaea gigas) and the acute and diverging tips of the eyestalks (which are short, blunt and not diverging in Neotrypaea biffari).^[3]

Ecology and human impact

Oyster farming (seen here in Willapa Bay, Washington in 1969) is adversely affected by N. californiensis.

Both Neotrypaea californiensis and the mud shrimp Upogebia pugettensis live in mudflats and sandy substrates in the intertidal zone of estuaries in western North America. N. californiensis is found from Mutiny Bay, Alaska^[6] to Punta Abreojos, Mulegé, Baja California Sur, Mexico.^[7] Its habitat is also used for the aquaculture of the Pacific oyster, Crassostrea gigas.^[5] Since the bioturbation carried out by N. californiensis and U. pugettensis reduces the productivity of the oyster beds, they are considered pests. Their effects may, however, have knock-on effects across the entire ecosystem, and may buffer it from the hazards of nutrient enrichment and increase primary and secondary productivity by increasing the amount of dissolved inorganic nitrogen.^[8]

The burrows made by N. californiensis have many branches,^[9] and a number of other animals live in them, including snapping shrimp of the genus Betaeus,^[3][10] the copepod Clausidium vancouverense,^[11] and the crab Scleroplax granulata.^[12] The gut flora of N. californiensis includes a wide range of bacteria, comprising around 40% Alphaproteobacteria, 20% gram-positive bacteria, 20% in the Cryptophaga–Flavobacteria–Bacteroides group, and 5% of each of Gammaproteobacteria and Epsilonproteobacteria.^[13] Predators of N. californiensis include bottom-dwelling fish^[9] and Dungeness crabs (Metacarcinus magister).^[14]

N. californiensis has a negative impact on oyster production, and as a result, the insecticide carbaryl (1-napthyl N-methyl carbamate) is sprayed in some areas (including Willapa Bay, Washington) to reduce the population of N. californiensis.^[15] The addition of shelly debris also reduces numbers of N. californiensis both by preventing the settlement of larvae, and through predation on the young N. californiensis by young Dungeness crabs in the shelly debris.^[14]

N. californiensis is used as fishing bait, and is frequently transported alive between U.S. states, prompting fears that existing population structure may be obliterated, and that it could introduce the castrating parasitic isopod Ione cornuta outside its native range.^[16]

References

1. ^ "Callianassa californiensis Dana, 1854". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=97737. Retrieved August 17, 2011. 
2. ^ ^{a b c} Lipke B. Holthuis (1991). "Callianassa californiensis". Marine Lobsters of the World. FAO Fisheries Synopsis. 125. Food and Agriculture Organization. pp. 244–245. ISBN 978-92-5-103027-1. http://nlbif.eti.uva.nl/bis/lobsters.php?menuentry=soorten&id=68. 
3. ^ ^{a b c d e f} Mary K. Wicksten (April 17, 2009). "Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces" (PDF). Scripps Institution of Oceanography, University of California San Diego. http://escholarship.org/uc/item/7sk9t2dz. 
4. ^ ^{a b c} Linda V. Labadie & A. R. Palmer (1996). "Pronounced heterochely in the ghost shrimp, Neotrypaea californiensis (Decapoda: Thalassinidea: Callianassidae): allometry, inferred function and development". Journal of Zoology 240 (4): 659–675. doi:10.1111/j.1469-7998.1996.tb05314.x. 
5. ^ ^{a b} Brett Dumbauld, Kristine Feldman & David Armstrong (2004). "A comparison of the ecology and effects of two species of thalassinidean shrimps on oyster aquaculture operations in the eastern North Pacific". In A. Tamaki (PDF). Proceedings of the Symposium on Ecology of Large Bioturbators in Tidal Flats and Shallow Sublittoral Sediments – From Individual Behavior to Their Role as Ecosystem Engineers. Nagasaki: Nagasaki University. pp. 53–61. http://afrsweb.usda.gov/SP2UserFiles/person/36110/dumbauld2.pdf. 
6. ^ G. E. MacGinitie (1934). "The natural history of Callianassa californiensis Dana". American Midland Naturalist 15 (2): 166–177. JSTOR 2420244. 
7. ^ Ernesto Campos, Alma de Campos & Iván Manriquez (2009). "Intertidal thalassinidean shrimps (Thalassinidea, Callianassidae and Upogebiidae) of the west coast of Baja California, Mexico: annotated checklist, key for identification, and symbionts". Crustaceana 82 (10): 1249–1263. doi:10.1163/001121609X12481627024454. 
8. ^ R. James, A. Atkinson & Alan C. Taylor (2005). "Aspects of the physiology, biology and ecology of thalassinidean shrimps in relation to their burrow environment". In R. N. Gibson, R. J. A. Atkinson & J. D. M. Gordon. Oceanography and Marine Biology: An Annual Review. 43. CRC Press. pp. 173–210. ISBN 978-0-8493-3597-6. 
9. ^ ^{a b} Mike Schaadt, Ed Mastro & Cabrillo Marine Aquarium (2009). "Mudflat (Salinas de San Pedro)". Cabrillo Beach Coastal Park. Images of America. Arcadia Publishing. pp. 107–118. ISBN 978-0-7385-7189-8. 
10. ^ Raymond T. Bauer (2004). "Symbioses". Remarkable Shrimps: Adaptations and Natural History of the Carideans. Animal natural history series. 7. University of Oklahoma Press. pp. 179–203. ISBN 978-0-8061-3555-7. 
11. ^ Arthur D. Humes (1949). "A new copepod (Cyclopoida: Clausidiidae) parasitic on mud shrimps in Louisiana". Transactions of the American Microscopical Society 68 (2): 93–103. JSTOR 3223256. PMID 18153316. 
12. ^ Ernesto Campos (2006). "Systematics of the genus Scleroplax Rathbun, 1893 (Crustacea: Brachyura: Pinnotheridae)" (PDF). Zootaxa 1344: 33–41. http://mapress.com/zootaxa/2006f/zt01344p041.pdf. 
13. ^ W. W. Y. Lau, P. A. Jumars & E. V. Armbrust (2002). "Genetic diversity of attached bacteria in the hindgut of the deposit-feeding shrimp Neotrypaea (formerly Callianassa) californiensis (Decapoda: Thalassinidae)". Microbial Ecology 43 (4): 455–466. doi:10.1007/s00248-001-1043-3. 
14. ^ ^{a b} K. L. Feldman, D. A. Armstrong, B. R. Dumbauld & C. J. Langdon (1995). Controlling populations of burrowing thalassinid shrimp on oyster culture grounds: effects of harvesting and shell configuration on recruitment of young-of-the-year. "Abstracts of technical papers presented at Aquaculture '95, Triennial Meeting of the Fish Culture Section of the American Fisheries Society, World Aquaculture Society, and the National Shellfisheries Association, San Diego, California, February 1–4, 1995". Journal of Shellfish Research 14 (1): 265. http://md1.csa.com/partners/viewrecord.php?requester=gs&collection=ENV&recid=3855291. 
15. ^ John Davenport, Kenneth Black, Gavin Burnell, Tom Cross, Sarah Culloty, Suki Ekaratne, Bob Furness, Maire Mulcahy & Helmut Thetmeyer (2003). "Physical change to the habitat". Aquaculture: the Ecological Issues. Ecological Issues. 3. Wiley-Blackwell for the British Ecological Society. pp. 19–27. ISBN 978-1-4051-1241-3. 
16. ^ Bruno Pernet, Aimee Deconinck, Angela Llaban & James W. Archie (2008). "Evaluating risks associated with transport of the ghost shrimp Neotrypaea californiensis as live bait". Marine Biology 153 (6): 1127–1140. doi:10.1007/s00227-007-0884-9.