Neotrypaea californiensisbay ghost shrimp

Geographic Range

Neotrypaea californiensis can be found at intertidal locations within the regions of the North American West Coast ranging from Mutiny Bay, Alaska to Tijuana River, San Diego County, California and El Estuario de Punto Banda, Baja California Norte, Mexico. (MacGinitie, 1934; Ricketts and Calvin, 1968)


Neotrypaea californiensis live as infauna in intertidal areas between the middle to low intertidal zones, on sandy beaches or tidal flats in estuaries. Ghost shrimp habitat is distinguished by numerous holes that are the entrances and exits of their burrows. Ghost shrimp are constantly excavating complex tunnels under the sand. (MacGinitie, 1934)

Although the majority of time is spent building tunnels, ghost shrimp do come to the surface at times, where predation can occur. (Posey, 1985)

  • Range depth
    0.76 (low) m
    2.49 (low) ft

Physical Description

Body coloration ranges between shades of orange, pink, and red. Some individuals may also exhibit a very pale coloration, almost white. The main body parts of Neotrypaea californiensis follow a generalized decapod body plan: two differently-shaped claws (with one major cheliped, often several times larger than the opposite claw); five pairs of legs, three paddle-shaped swimming legs (pleopods), a fan-like tail (uropod), telson, flattened eyestalks, and two pairs of antennae. The exoskeleton is fringed with numerous fine hairs. (MacGinitie, 1934)

Females bearing eggs carry them on their abdomen. The egg mass may vary in color between individuals, from light yellow to deep scarlet. The major cheliped is sexually dimorphic, being larger on males. The major cheliped can account for up to a quarter of a ghost shrimp's weight. (Labadie and Palmer, 1996)

  • Sexual Dimorphism
  • male larger
  • sexes shaped differently
  • Average mass
    1-5 g
  • Average length
    10-12 cm


Neotrypaea californiensis matures between 18 and 24 months. Mature individuals can be found closest to the ocean and they grow much faster compared to individuals located nearer to shore. Larger sized females with larger eggs can be found within intertidal areas.

Females carry their fertile eggs on their abdomen and the eggs are released in June or July. The newly released ghost shrimp larvae (zoea) drift for six to eight weeks in the water column as zooplankton, passing through five zoeal stages before transforming into a megalops. There zoeal stages take place over 6 to 8 weeks. They will return to estuarine habitats as megalopae on flood tides during August. (Bird, 1982; MacGinitie, 1934; McCrow, L.T., 1972)


Using olfactory receptors on their antennules called aesthetascs, a male ghost shrimp detects water soluble substances released by premolt females. Once a female is found, the male will follow and protect her from predators and other suitors with his major cheliped, until she molts. This process is known as temporary mate guarding. After the female molts, the male mates with her and then leaves her to find another premolt female. (Bauer, 2011; Labadie and Palmer, 1996)

Though the mating behavior of the ghost shrimp is largely unknown, it is agreed that the males use the major cheliped to fight other males for reproductive access to females.

The female will carry her brood of eggs for approximately 3 to 5 months. Hatching occurs in June or July. The newly released ghost shrimp larvae (zoea) drift for six to eight weeks in the water column as zooplankton, passing through five zoeal stages before transforming into a megalops. They will return to estuarine habitats as megalopae on flood tides during August. (Horning, et al., 1989; Labadie and Palmer, 1996)

  • Breeding interval
    April to August
  • Breeding season
    Begins in April
  • Range number of offspring
    200 to 1,400
  • Range gestation period
    3 to 5 months
  • Average time to independence
    Eggs are carried and protected by the female for 3- 5 months before hatching, releasing larvae into the water column as plankton months
  • Average age at sexual or reproductive maturity (female)
    18-24 months months
  • Average age at sexual or reproductive maturity (male)
    18-24 months months

Ghost shrimp reproduce seasonally. The female will carry her brood of eggs for approximately 3 to 5 months until they hatch, usually in June or July. (Horning, et al., 1989)


Ghost shrimp in the wild have an average lifespan of 3-5 years. The primary factor affecting lifespan is the level of available nutrients. Nutrient availability is directly related to the distance of the colony to an estuary. Longer-lived shrimp are found closer the mouth of an estuary. (Bird, 1982; Dumbauld, et al., 1996)

  • Average lifespan
    Status: wild
    5 years
  • Average lifespan
    Status: wild
    3-5 years


Water temperature and substrate characteristics can also influence shrimp activities, as colder temperatures reduce shrimp mobility and sandy sediments reduce its ability to burrow.

Ghost shrimp in general are constantly burrowing to obtain food. (Horning, et al., 1989; Pernet, B., Deconinck, A., and Haney, L, 2010; Wicksten, 2008)

Home Range

Ghost shrimp conduct their daily activities within a relatively small circumscribed area. Under experimental conditions, ghost shrimp spent over 25% of the time within 2 cm of the burrow entrance; furthermore, the shrimp were also observed to move from one burrow to another. (Posey, 1985; Wicksten, 2008)

Ghost shrimp territory is limited to a few cm within the vicinity of their own burrow, which they defend from rivals. Population size can be very dense with burrows directly adjacent to those of conspecifics. In Oregon, densities have been estimated at 700-1,400 per square meter in Yaquina bay; 420-770 per square meter in Sand Lake Estuary, and less than 300 per square meter along the coast. (Bird, 1982; McCrow, L.T., 1972)

Communication and Perception

Tactile: This species uses its antennae, chelipeds, and sensory hairs (called cuticular mechanoreceptors, covering most of the body) to sense physical objects in the environment.

Vision: Eyestalks are acute with divergent tips, and bear a pigmented cornea in the middle of the eyestalk. (Nau, 2004)

Food Habits

Ghost shrimp ingest plankton and detritus deposits scraped from the sediments during burrowing. Plankton is also obtained as water and detrital materials pass over the body and are collected on the hairs of their second and third walking legs. (Nau, 2004)

To find enough food, ghost shrimp tunnel almost constantly, reworking the sediment to a depth of as much as 76 cm. (Horning, et al., 1989)


Although ghost shrimp typically inhabit deep burrows, they are susceptible to predation because they sometimes venture outside of their burrow entrances. Fishes and invertebrates are significant predators when the tide is high, whereas shorebirds and humans prey on ghost shrimp when the tide is low. Shorebirds that feed on ghost shrimp include the long-billed curlew Numenius americanus and the willet Catoptrophorus semipalmatus. Some fish predators include the Pacific staghorn sculpin, Leptocottus armatus. (Light, S., Carlton, T, 2007; Posey, 1985; Posey, M. H, 1986; Stenzel, L., Huber, H., and Page, P, 1976)

Ecosystem Roles

The vigorous burrowing activities of ghost shrimp have such dramatic effects on their habitats of soft sediment that these animals are often considered ecosystem engineers. By aerating the surface sediment through burrowing, the ghost shrimp provide an environment attractive to other species including the blind goby, three species of pea crabs, two species of clams, a copepod, a shrimp, polynoid worms, and isopods, all of which live within the burrows. (Horning, et al., 1989; Pernet, B., Deconinck, A., and Haney, L, 2010)

Commensal/Parasitic Species

Economic Importance for Humans: Positive

Neotrypaea californiensis is used as live bait by fishermen. Fishermen commonly call them one-armed bandits because of their one long cheliped. (Nau, 2004)

  • Positive Impacts
  • food

Economic Importance for Humans: Negative

No known negative economic importance for humans.

Conservation Status

Other Comments

Neotrypaea californiensis is tolerant of low oxygen conditions, and laboratory results indicate this species can survive anoxic conditions for as long as 3 days. (Thompson and Pritchard, 1969)


Stephanie Astle (author), San Diego Mesa College, Victoria Hosford (author), San Diego Mesa College, Dennis Ramirez (author), San Diego Mesa College, Paul Detwiler (editor), San Diego Mesa College, Renee Mulcrone (editor), Special Projects, Alexa Unruh (editor), Animal Diversity Web Staff.



living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map


Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate


the nearshore aquatic habitats near a coast, or shoreline.


an animal that mainly eats decomposed plants and/or animals


particles of organic material from dead and decomposing organisms. Detritus is the result of the activity of decomposers (organisms that decompose organic material).


animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature


an area where a freshwater river meets the ocean and tidal influences result in fluctuations in salinity.

female parental care

parental care is carried out by females


union of egg and spermatozoan


a method of feeding where small food particles are filtered from the surrounding water by various mechanisms. Used mainly by aquatic invertebrates, especially plankton, but also by baleen whales.


A substance that provides both nutrients and energy to a living thing.


having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

internal fertilization

fertilization takes place within the female's body

intertidal or littoral

the area of shoreline influenced mainly by the tides, between the highest and lowest reaches of the tide. An aquatic habitat.


marshes are wetland areas often dominated by grasses and reeds.


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.


photosynthetic or plant constituent of plankton; mainly unicellular algae. (Compare to zooplankton.)


an animal that mainly eats plankton


the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

seasonal breeding

breeding is confined to a particular season


remains in the same area


reproduction that includes combining the genetic contribution of two individuals, a male and a female

soil aeration

digs and breaks up soil so air and water can get in


lives alone


uses touch to communicate


uses sight to communicate

young precocial

young are relatively well-developed when born


animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)


Bauer, R. 2011. Chemical Communication in Crustaceans. New York: Springer. Accessed June 21, 2011 at

Bird, E. 1982. Population dynamics of thalassinidean shrimps and community effects through sediment modification. Ph.D. Dissertation. University of Maryland, College Park: 1-151.

Dumbauld, B., D. Armstrong, K. Feldman. 1996. Life history characteristics of two sympatric thalassinidean shrimps, Neotrypaea californiensis and Upogebia pugettensis, with implications for oyster culture. Journal of Crustacean Biology, 16(4): 689-708.

Horning, S., A. Sterling, S. Smith. 1989. Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (Pacific Northwest)--ghost shrimp and blue mud shrimp. U.S. Fish Wildlife Service, Report No. TR EL-82-4: 1-15.

Labadie, L., A. 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.

Light, S., Carlton, T, 2007. The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon. ISBN 0520239393, 9780520239395: University of California Press.

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MacGinitie, G. 1935. Ecological aspects of a California marine estuary. American Midland Naturalist, 16: 629-765.

MacGinitie, G., N. MacGinitie. 1968. Natural history of marine animals, 2nd ed.. New York: NcGraw-Hill.

McCrow, L.T., 1972. The ghost shrimp Callianassa californiesis Dana, 1854, in Yaquina Bay, Oregon. M.S. Thesis. Oregon State University, Corvallis: 56.

Morris, R., D. Abbott, E. Haderlie. 1980. Intertidal invertebrates of California. Stanford: Stanford University Press.

Nau, F. 2004. "Callianassa californiensis (Dana, 1854)" (On-line). Accessed June 20, 2011 at

Pernet, B., Deconinck, A., and Haney, L, 2010. Molecular morphological markers for distinguishing the sympatric intertidal ghost shrimp Neotrypaea californiensis and N. gigas in the Eastern Pacific. Journal of Crustacean Biology, 30 (2): 323-331.

Posey, M. H, 1986. Changes in a benthic community associated with dense beds of a burrowing deposit feeder Callianassa californiensis. Marine Ecology Progress Series, 31: 15-22.

Posey, M. 1986. Predation on a burrowing shrimp: distribution and community consequences. Journal of Experimental Marine Biology and Ecology, 103: 143 -161.

Posey, M. 1985. The effects upon the macrofaunal community of a dominant burrowing deposit feeder, Callianassa californienis, and the role of predation in determining its intertidal distrution. PhD Dissertation: 1-119.

Ricketts, E., J. Calvin. 1968. Low Intertidal. Pp. 237 in J Hedgpeth, ed. Between Pacific Tides. Stanford, CA: Stanford University Press.

Shimoda, K., Wardiatno, Y., Kubo K. and Tamaki, A, 2005. Intraspecific behaviors and major cheliped sexual dimorphism in three congeneric callianassid shrimp. Marine Biology, 146(3): 543-557.

Stenzel, L., Huber, H., and Page, P, 1976. Feeding behavior and diet of the long-billed curlew and willet. The Wilson Bulletin, 88(2): 314-332.

Thompson, R., A. Pritchard. 1969. Respiratory adaptations of two burrowing crustaceans, Callianassa californiensis and Upogebia pugettensis (Decapoda, Thalassinidea). Biological Bulletin, 136: 274-287.

Wicksten, M. 2008. Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces. Scripps Institution of Oceanography Library Paper, 26: 1-413. Accessed June 20, 2011 at