Caridea
| Caridea Temporal range:
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| Heterocarpus ensifer | |
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| Infraorder: | Caridea Dana, 1852
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Caridea is an infraorder within the order Decapoda, generally known as shrimp. They are swimming animals which are found widely around the world in both fresh and salt water.
Biology
Caridean shrimp are found in every kind of aquatic habitat, with the majority of species being marine. Around a quarter of the described species are found in fresh water, however, including almost all the members of the species-rich family Atyidae and the Palaemonidae subfamily Palaemoninae.[1] They include several commercially important species, such as Macrobrachium rosenbergii, and are found on evrey continent except Antarctica.[1] The marine species are found at depths of up to 5,000 metres (16,000 ft),[2] and from the tropics to the polar regions.
As well as the great variety in habitat, shrimp vary greatly in form, from species a few millimetres long when fully grown,[3] to those that grow to over a foot long.[2] Except where secondarily lost, shrimp have one pair of stalked eyes, although they are sometimes covered by the carapace, which protects the cephalothorax.[2] The carapace also surrounds the gills, through which water is pumped by the action of the mouthparts.[2]
Most shrimp are omnivorous, but some are specialised for particular modes of feeding. Some are filter feeders, using their setose (bristly) legs as a sieve; some scrape algae from rocks. The snapping shrimp of the genus Alpheus snap their claws to create a shock wave that stuns prey. Many cleaner shrimp, which groom reef fish and feed on their parasites and necrotic tissue, are carideans.[2] In turn, shrimp are eaten by various animals, particularly fish and seabirds, and frequently host bopyrid parasites.[2]
Life cycle
In most species of caridean shrimp, the females lay 50,000 to 1 million eggs, which hatch after some 24 hours into tiny nauplii. These nauplii feed on yolk reserves within their body and then undergo a metamorphosis into zoeae. This second larval stage feeds in the wild on algae and after a few days metamorphoses again into the third stage to become myses. At this stage the myses already begin to appear like tiny versions of fully developed adults and feed on algae and zooplankton. After another three to four days they metamorphose a final time into postlarvae: young shrimp having all the characteristics of adults. The whole process takes about 12 days from hatching. In the wild, the marine postlarvae then migrate into estuaries, which are rich in nutrients and low in salinity. There they grow and eventually migrate back into open waters when they mature. Most adult shrimp are benthic animals living primarily on the sea floor.
Common shrimp species include Pandalus borealis (the "pink shrimp"), Crangon crangon (the "brown shrimp") and the snapping shrimp of the genus Alpheus. Depending on the species and location, they grow from about 1.2 to 30 centimetres (0.47 to 11.81 in) long, and live between one and 6.5 years.[4]
Taxonomy
Shrimp of the infraorder Caridea are more closely related to lobsters and crabs than they are to the members of the sub-order Dendrobranchiata (prawns).[5] Biologists distinguish the two groups based on differences in their gill structures. The gill structure is lamellar in shrimp but branching in prawns. The easiest practical way to separate true shrimps from true prawns is to examine the second abdominal segment. The second segment of a shrimp overlaps both the first and the third segment, while the second segment of a prawn overlaps only the third segment.[6] They also differ in that carideans typically have two pairs of chelae (claws), while dendrobranchiates have three.[7]
A third group, Stenopodidea, contains around 70 species and differs in that the third pairs of legs is greatly enlarged, a feature not seen in the other groups.[7]
The infraorder Caridea is divided into 16 superfamilies:[8]
- Alpheoidea Rafinesque, 1815
- Atyoidea De Haan, 1849
- Bresilioidea Calman, 1896
- Campylonotoidea Sollaud, 1913
- Crangonoidea Haworth, 1825
- Galatheacaridoidea Vereshchaka, 1997
- Nematocarcinoidea Smith, 1884
- Oplophoroidea Dana, 1852
- Palaemonoidea Rafinesque, 1815
- Pandaloidea Haworth, 1825
- Pasiphaeoidea Dana, 1852
- Physetocaridoidea Chace, 1940a
- Procaridoidea Chace & Manning, 1972
- Processoidea Ortmann, 1896
- Psalidopodoidea Wood-Mason, 1892
- Stylodactyloidea Bate, 1888
The fossil record of shrimp is sparse, with only 57 exclusively fossil species known.[8] The earliest of these cannot be assigned to any family, but date from the Lower Jurassic and Cretaceous.[9] A number of extinct genera cannot be placed in any superfamily:[8]
- Acanthinopus Pinna, 1974
- Alcmonacaris Polz, 2009
- Bannikovia Garassino & Teruzzi, 1996
- Blaculla Münster, 1839
- Buergerocaris Schweigert & Garassino, 2004
- Gampsurus von der Marck, 1863
- Hefriga Münster, 1839
- Leiothorax Pinna, 1974
- Parvocaris Bravi & Garassino, 1998
- Pinnacaris Garassino & Teruzzi, 1993
Commercial fishing
Common commercial methods for catching shrimp and prawns include otter trawls, cast nets, seines, shrimp baiting and dip netting. Trawling involves the use of a system of nets. In some parts of the Pacific Northwest, fishing with baited traps is also common.
The following table shows the yearly weight of shrimp and prawns captured globally in millions of tonnes:[10]
| Production | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 |
|---|---|---|---|---|---|---|---|
| Million tonnes | 3.03 | 3.09 | 2.96 | 2.97 | 3.55 | 3.54 | 3.42 |
The highest rates of incidental catch of non-target species is associated with shrimp trawling. In 1997, the FAO documented the estimated bycatch and discard levels from shrimp fisheries around the world. They found discard rates as high as 20 pounds for every pound of shrimp, with a world average of 5.7 pounds for every pound of shrimp.[11]
Trawl nets in general, and shrimp trawls in particular, have been identified as sources of mortality for species of finfish and cetaceans.[12] Bycatch is often discarded dead or dying by the time it is returned to the sea, and may alter the ecological balance in discarded regions.[13] Worldwide, shrimp trawl fisheries generate about 2% of the world’s catch of fish in weight, but result in more than one third of the global bycatch total.
Farming
Shrimp farms are aquaculture businesses that cultivate marine shrimp or prawns for human consumption. Commercial shrimp farming began in the 1970s and production grew steeply, particularly to match the market demands of the United States, Japan and parts of Western Europe.
The total global production of farmed shrimp reached more than 1.6 million tonnes in 2003, representing a value of nearly 9 billion U.S. dollars. About 75% of farmed shrimp are produced in Asia, in particular in China, Thailand and in the Philippines (normally shrimp or prawns are caught in lake, river and sea and are not farmed in tanks). The other 25% are produced mainly in Latin America, where Brazil is the largest producer. The largest exporting nation is Thailand. In Southeast Asia, mangroves are continually taken over then discarded after several years, leading to the equivalent of a ton of carbon dioxide emissions per pound of shrimp produced.[14]
The global annual production of freshwater shrimp and prawns in 2003 was about 280,000 tons, of which China produced some 180,000 tons, followed by India and Thailand with some 35,000 tons each.[15]
References
- ^ a b S. De Grave, Y. Cai & A. Anker (2008). Estelle Virginia Balian, C. Lévêque, H. Segers & K. Martens (ed.). "Freshwater Animal Diversity Assessment". Hydrobiologia. 595 (1). Springer: 287–293. doi:10.1007/s10750-007-9024-2. ISBN 978-1-4020-8258-0.
{{cite journal}}:|chapter=ignored (help)CS1 maint: multiple names: editors list (link) - ^ a b c d e f Fenner A. Chace, Jr. & Donald P. Abbott (1980). "Caridea: the shrimps". In Robert Hugh Morris, Donald Putnam Abbott & Eugene Clinton Haderlie (ed.). Intertidal Invertebrates of California. Stanford University Press. pp. 567–576. ISBN 978-0-8047-1045-9.
- ^ Gary C. B. Poore & Shane T. Ahyong (2004). "Caridea – shrimps". Marine Decapod Crustacea of Southern Australia: a Guide to Identification. CSIRO Publishing. pp. 53–57. ISBN 9780643069060.
- ^ "A bouillabaisse of fascinating facts about fish". NOAA: National Marine Fisheries Service. Retrieved October 22, 2009.
- ^ "Biology of Shrimps". Museum Victoria Australia. Retrieved January 9, 2010.
- ^ Charles Raabe & Linda Raabe (2008). "The Caridean shrimp: Shrimp Anatomy - Illustrations and Glossary".
- ^ a b Raymond T. Bauer (2004). "What is a caridean shrimp?". Remarkable Shrimps: Adaptations and Natural History of the Carideans. Animal Natural History Series. Vol. 7. University of Oklahoma Press. pp. 3–14. ISBN 978-0-8061-3555-7.
- ^ a b c Sammy De Grave, N. Dean Pentcheff, Shane T. Ahyong; et al. (2009). "A classification of living and fossil genera of decapod crustaceans" (PDF). Raffles Bulletin of Zoology. Suppl. 21: 1–109.
{{cite journal}}: Explicit use of et al. in:|author=(help)CS1 maint: multiple names: authors list (link) - ^ Fenner A. Chace, Jr. & Raymond B. Manning (1972). "Two new caridean shrimps, one representing a new family, from marine pools on Ascension Island (Crustacea: Decapoda: Natantia)" (PDF). Smithsonian Contributions to Zoology. 131: 18 pp.
- ^ State of the World Fisheries and Aquaculture 2006. FAO. 2007. ISBN 978-92-5-105568-7.
- ^ Ivor Clucas (1997). Discards and bycatch in shrimp trawl fisheries. Fisheries Circular No. 928 FIIU/C928. Food and Agriculture Organization.
- ^ "Final Habitat Plan for the South Atlantic Region". South Atlantic Fisheries Management Council. 1998.
- ^ Lance E. Morgan & Ratana Chuenpagdee (2003). Shifting Gears. Addressing the Collateral Impacts of Fishing Methods in U.S. Waters (PDF). Pew science series on conservation and the environment. Island Press. ISBN 1-55963-659-9.
- ^ Dashiell Bennett (February 20, 2012). "Your shrimp cocktail is ruining the planet". The Atlantic Wire. Retrieved July 26, 2012.
- ^ Data extracted from the FAO Fisheries Global Aquaculture Production Database for freshwater crustaceans. The most recent data sets are for 2003 and sometimes contain estimates. Accessed June 28, 2005.
