''Neotrypaea californiensis'' (formerly ''Callianassa californiensis''), the Bay ghost shrimp, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of ghost shrimp that lives on the

Pacific coast Pacific coast may be used to reference any coastline that borders the Pacific Ocean. Geography Americas North America Countries on the western side of North America have a Pacific coast as their western or south-western border. One of th ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. It is a pale animal which grows to a length of . One claw is bigger than the other, especially in males, and the enlarged claw is thought to have a function in

mating In biology, mating is the pairing of either opposite-sex or hermaphroditic organisms for the purposes of sexual reproduction. ''Fertilization'' is the fusion of two gametes. '' Copulation'' is the union of the sex organs of two sexually repr ...

. ''N. californiensis'' is a deposit feeder that lives in extensive burrow systems, and is responsible for high rates of

bioturbation Bioturbation is defined as the reworking of soils and sediments by animals or plants. It includes burrowing, ingestion, and defecation of sediment grains. Bioturbating activities have a profound effect on the environment and are thought to be a ...

. 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 Bait may refer to: General * Bait (luring substance), bait as a luring substance ** Fishing bait, bait used for fishing Film * ''Bait'' (1950 film), a British crime film by Frank Richardson * ''Bait'' (1954 film), an American noir film by Hugo ...

Description and life cycle

''Neotrypaea californiensis'' reaches a length of . The body is creamy white, with patches of pale colour (pink, yellow or orange) on the

appendage An appendage (or outgrowth) is an external body part or natural prolongation that protrudes from an organism's body such as an arm or a leg. Protrusions from single-celled bacteria and archaea are known as cell-surface appendages or surface app ...

s, and a pink

abdomen The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...

. 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. The enlarged claw is equally likely to be on the right side or the left side. The male's larger claw is thought to be used in agonistic encounters or during

, and may be the result of

sexual selection Sexual selection is a mechanism of evolution in which members of one sex mate choice, choose mates of the other sex to mating, mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex ...

. Eggs are laid in spring or early summer, and the

larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...

hatch in summer, living as

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

. They settle to the sea floor again as post-larvae in the late summer and fall.

Taxonomy

''N. californiensis'' was originally described in 1854 by

James Dwight Dana James Dwight Dana Royal Society of London, FRS FRSE (February 12, 1813 – April 14, 1895) was an American geologist, mineralogist, volcanologist, and zoologist. He made pioneering studies of mountain-building, volcano, volcanic activity, and the ...

as a member of the genus ''

Callianassa ''Callianassa'' is a genus of mud shrimps, in the family Callianassidae. Three of the species in this genus ('' C. candida'', '' C. tyrrhena'' and '' C. whitei'') have been split off into a new genus, '' Pestarella'', while others such as '' Ca ...

'', giving the type locality as "California"; the material Dana studied was probably collected from

San Francisco Bay San Francisco Bay (Chochenyo language, Chochenyo: 'ommu) is a large tidal estuary in the United States, U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the cities of San Francisco, California, San ...

Monterey Monterey ( ; ) is a city situated on the southern edge of Monterey Bay, on the Central Coast of California. Located in Monterey County, the city occupies a land area of and recorded a population of 30,218 in the 2020 census. The city was fou ...

, but the original specimens have since been lost. In 1991,

Raymond Manning Raymond Brendan Manning (October 11, 1934 – January 18, 2000) was an American carcinologist, specialising in alpha taxonomy and mantis shrimp. His zoological author abbreviation is Manning or sometimes R.B. Manning. He has authored over 500 taxa. ...

and Darryl Felder transferred the three species in that genus that come from

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

and

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

into the new genus '' Neotrypaea''. ''N. californiensis'' is distinguished from the other two species of ''Neotrypaea'' by the lack of a

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit ** podium * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ...

(which is present in '' Neotrypaea gigas'') and the acute and diverging tips of the

eyestalk In anatomy, an eyestalk (sometimes spelled eye stalk and also known as an ommatophore) is a protrusion that extends an eye away from the body, giving the eye a better field of view. It is a common feature in nature and frequently appears in fict ...

s (which are short, blunt and not diverging in ''

Neotrypaea biffari ''Neotrypaea'' is a genus of ghost shrimp in the family Callianassidae, containing the following sixteen species: *'' Neotrypaea biffari'' (Holthuis, 1991) ** of which, ''Neotrypaea affinis'' (Holmes, 1900) is a synonym *'' Neotrypaea caesari'' ...

'').

Ecology and human impact

Both ''Neotrypaea californiensis'' and the mud shrimp '' Upogebia pugettensis'' live in

mudflat Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal ...

s and

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is usually defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural ...

y substrates in the

intertidal zone The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various ...

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

in western North America. ''N. californiensis'' is found from Mutiny Bay,

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

Punta Abreojos Punta Abreojos is a fishing town in the municipality of Mulegé, Baja California Sur, Mexico. It is located at the entrance to Laguna La Bocana, and is close to Estero Coyote.]s. #Rains, Rains (2006) An isolated hill, high, rises a few miles beh ...

, Mulegé (municipality), Mulegé,

Baja California Sur Baja California Sur, officially the Free and Sovereign State of Baja California Sur, is a state in Mexico. It is the 31st and last state to be admitted, in 1974. It is also the second least populated Mexican state and the ninth-largest state by ...

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

. Its habitat is also used for the

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. Nelu ...

of the

Pacific oyster The Pacific oyster, Japanese oyster, or Miyagi oyster (''Magallana gigas'') is an oyster native to the Pacific coast of Asia. It has become an introduced species in North America, Australia, Europe, and New Zealand. Etymology The genus ''Magal ...

, ''Crassostrea gigas''. Since the

carried out by ''N. californiensis'' and ''U. pugettensis'' reduces the productivity of the

oyster bed Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but no ...

s, they are considered

pests PESTS was an anonymous American activist group formed in 1986 to critique racism, tokenism, and exclusion in the art world. PESTS produced newsletters, posters, and other print material highlighting examples of discrimination in gallery represent ...

. Their effects may, however, have knock-on effects across the entire

ecosystem An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...

, and may buffer it from the hazards of nutrient enrichment and increase

primary Primary or primaries may refer to: Arts, entertainment, and media Music Groups and labels * Primary (band), from Australia * Primary (musician), hip hop musician and record producer from South Korea * Primary Music, Israeli record label Work ...

and secondary productivity by increasing the amount of dissolved inorganic

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

. The burrows made by ''N. californiensis'' have many branches, and a number of other animals live in them, including

snapping shrimp Alpheidae (also known as the snapping shrimp, pistol shrimp or alpheid shrimp) is a family within the shrimp infraorder Caridea characterized by having asymmetrical claws, the larger of which is typically capable of producing a loud snapping sou ...

of the genus '' Betaeus'', the

copepod Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (living in the water column), some are benthos, benthic (living on the sedimen ...

'' Clausidium vancouverense'', and the

crab Crabs are decapod crustaceans of the infraorder Brachyura (meaning "short tailed" in Greek language, Greek), which typically have a very short projecting tail-like abdomen#Arthropoda, abdomen, usually hidden entirely under the Thorax (arthropo ...

'' Scleroplax granulata''. The

gut flora Gut microbiota, gut microbiome, or gut flora are the microorganisms, including bacteria, archaea, fungi, and viruses, that live in the digestive tracts of animals. The gastrointestinal metagenome is the aggregate of all the genomes of the g ...

of ''N. californiensis'' includes a wide range of

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

, comprising around 40%

Alphaproteobacteria ''Alphaproteobacteria'' or ''α-proteobacteria'', also called ''α-Purple bacteria'' in earlier literature, is a class of bacteria in the phylum '' Pseudomonadota'' (formerly "Proteobacteria"). The '' Magnetococcales'' and '' Mariprofundales'' ar ...

, 20%

gram-positive bacteria In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. The Gram stain ...

, 20%

Bacteroidota The phylum (biology), phylum Bacteroidota (synonym Bacteroidetes) is composed of three large classes of Gram-negative bacteria, Gram-negative, nonsporeforming, anaerobic or aerobic, and rod-shaped bacteria that are widely distributed in the envir ...

, and 5% of each of

Gammaproteobacteria ''Gammaproteobacteria'' is a class of bacteria in the phylum ''Pseudomonadota'' (synonym ''Proteobacteria''). It contains about 250 genera, which makes it the most genus-rich taxon of the Prokaryotes. Several medically, ecologically, and scienti ...

and

Campylobacterota Campylobacterota are a phylum of Gram-negative bacteria. Taxonomy Until the 2021 revision of bacterial taxonomy by the ICSP, the entire phylum was classified within the Proteobacteria (synonym Pseudomonadota) as the Epsilonproteobacteria and ...

. Predators of ''N. californiensis'' include

gray whale The gray whale (''Eschrichtius robustus''), also known as the grey whale,Britannica Micro.: v. IV, p. 693. is a baleen whale that migrates between feeding and breeding grounds yearly. It reaches a length of , a weight of up to and lives between ...

s (''Eschrichtius robustus)'', bottom-dwelling

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

, and

Dungeness crab The Dungeness crab (''Metacarcinus magister'') makes up one of the most important seafood industries along the west coast of North America. Its typical range extends from Alaska's Aleutian Islands to Point Conception, near Santa Barbara, Califo ...

s (''Metacarcinus magister''). ''N. californiensis'' has a negative impact on

oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but no ...

production, and as a result, the

insecticide Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. The major use of insecticides is in agriculture, but they are also used in home and garden settings, i ...

carbaryl Carbaryl (1-naphthyl methylcarbamate) is a chemical in the carbamate family used chiefly as an insecticide. It is a white crystalline solid previously sold under the brand name Sevin, which was a trademark of the Bayer Company. Union Carbide disc ...

(1-napthyl N-methyl carbamate) is sprayed in some areas (including

Willapa Bay Willapa Bay () is a bay located on the southwest Pacific coast of Washington state in the United States. The Long Beach Peninsula separates Willapa Bay from the greater expanse of the Pacific Ocean. With over of surface area Willapa Bay is the ...

Washington Washington most commonly refers to: * George Washington (1732–1799), the first president of the United States * Washington (state), a state in the Pacific Northwest of the United States * Washington, D.C., the capital of the United States ** A ...

) to reduce the population of ''N. californiensis''. The addition of shelly debris also reduces numbers of ''N. californiensis'' both by preventing the settlement of

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e, and through predation on the young ''N. californiensis'' by young Dungeness crabs in the shelly debris. ''N. californiensis'' is used as

fishing bait Fishing bait is any bait (luring substance), luring substance used specifically to attract and fishing, catch fish, typically when angling with a fish hook, hook and fishing line, line. There are generally two types of baits used in angling: '' ...

, and is frequently transported alive between

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its so ...

s, prompting fears that existing population structure may be obliterated, and that it could introduce the

castrating Castration is any action, surgical, chemical, or otherwise, by which a male loses use of the testicles: the male gonad. Surgical castration is bilateral orchiectomy (excision of both testicles), while chemical castration uses pharmaceuti ...

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The ent ...

isopod Isopoda is an Order (biology), order of crustaceans. Members of this group are called isopods and include both Aquatic animal, aquatic species and Terrestrial animal, terrestrial species such as woodlice. All have rigid, segmented exoskeletons ...

Ione cornuta Ione may refer to: Places * Ione, California, a city * Ione, Colorado, an unincorporated community * Ione, Nevada, an unincorporated community * Ione, Oregon, a city * Ione, Washington, a town * Ionopolis or Ione, an ancient town near Antioc ...

'' outside its native range.

References

{{Authority control Axiidea Crustaceans of the eastern Pacific Ocean Crustaceans described in 1854