Amphipoda(/æmˈfɪpədə/) is anorderofmalacostracancrustaceanswith nocarapaceand generally with laterally compressed bodies. Amphipods (/ˈæmfɪpɒdz/) range in size from 1 to 340 millimetres (0.039 to 13 in) and are mostlydetritivoresorscavengers.There are more than 9,900 amphipod species so far described. They are mostly marine animals, but are found in almost all aquatic environments. Some 1,900 species live in fresh water, and the order also includes the terrestrialsandhopperssuch asTalitrus saltatorandArcitalitrus sylvaticus.
| Amphipoda Temporal range:
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| Gammarus roeselii | |
Scientific classification
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Malacostraca |
| Subclass: | Eumalacostraca |
| Superorder: | Peracarida |
| Order: | Amphipoda Latreille,1816[1] |
| Suborders | |
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Traditional division[2] Revised division (2013)[1] | |
Etymology and names
editThe nameAmphipodacomes, viaNeo-Latinamphipoda,from theGreekrootsἀμφί'on both/all sides' andπούς'foot'. This contrasts with the relatedIsopoda,which have a single kind of thoracic leg.[3]Particularly amonganglers,amphipods are known asfreshwater shrimp,scuds,orsideswimmers.[4][5]
Description
editAnatomy
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The body of an amphipod is divided into 13 segments, which can begrouped intoa head, athoraxand an abdomen.[4]
The head is fused to the thorax, and bears two pairs ofantennaeand one pair of sessilecompound eyes.[6]It also carries themouthparts,but these are mostly concealed.[7]
The thorax and abdomen are usually quite distinct and bear different kinds of legs; they are typically laterally compressed, and there is nocarapace.[6]The thorax bears eight pairs ofuniramousappendages,the first of which are used as accessorymouthparts;the next four pairs are directed forwards, and the last three pairs are directed backwards.[6]Gills are present on the thoracic segments, and there is anopen circulatory systemwith aheart,usinghaemocyaninto carryoxygenin thehaemolymphto the tissues. The uptake andexcretionofsaltsis controlled by specialglandson the antennae.[4]
The abdomen is divided into two parts: the pleosome which bearsswimming legs;and the urosome, which comprises atelsonand three pairs ofuropodswhich do not form a tail fan as they do in animals such astrue shrimp.[6]
Size
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Amphipods are typically less than 10 millimetres (0.4 in) long, but the largest recorded living amphipods were 28 centimetres (11 in) long, and were photographed at a depth of 5,300 metres (17,400 ft) in thePacific Ocean.[8]Samples retrieved from the stomach of ablack-footed albatrosshad a reconstructed length of 34 centimetres (13 in); it was assigned to the same species,Alicella gigantea.[9]A study of theKermadec Trenchobserved more specimens ofA. gigantea,the largest of which was estimated at 34.9 cm long, and collected some for examination, the largest of which was measured at 27.8 cm long.[10]The smallest known amphipods are less than 1 millimetre (0.04 in) long.[11]The size of amphipods is limited by the availability ofdissolved oxygen,such that the amphipods inLake Titicacaat an altitude of 3,800 metres (12,500 ft) can only grow up to 22 millimetres (0.87 in), compared to lengths of 90 millimetres (3.5 in) inLake Baikalat 455 metres (1,500 ft).[12]
Some amphipods exhibitsexual dimorphism.In dimorphic species, males are usually larger than females, although this is reversed in the genusCrangonyx.[13]
Reproduction and life cycle
editAmphipods engage inamplexus,a precopulatory guarding behavior in which males will grasp a female with their gnathopods (enlarged appendages used for feeding) and carry the female held against their ventral surface. Amplexus can last from two to over fifteen days, depending on water temperature, and ends when the female molts, at which point her eggs are ready for fertilisation.[13]
Mature females bear amarsupium,orbrood pouch,which holds hereggswhile they arefertilised,[4]and until the young are ready to hatch.[6]As a female ages, she produces more eggs in each brood. Mortality is around 25–50% for the eggs.[4]There are nolarvalstages; the eggs hatch directly into ajuvenileform, andsexual maturityis generally reached after 6moults.[4]Some species have been known to eat their ownexuviaeafter moulting[4]
Diversity and classification
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Over 10,500 species of amphipods are currently recognised.[14]Traditionally they were placed in the four subordersGammaridea,Caprellidea,Hyperiidea,andIngolfiellidea.[15] Suborder Gammaridea contained the majority of taxa, including all the freshwater andterrestrialspecies.[7]In contrast, the small suborder Ingolfiellidea only had 40 species.[16]
Gammaridea had been recognised as a problematic group in need of taxonomic revision.[15]It had nosynapomorphiesand became the repository for family-level taxa that didn't have synapomorphies for one of the other suborders.[17]A new classification that breaks up and replaces Gammaridea has been developed in the work of J. K. Lowry and A. A. Myers usingcladisticanalysis of morphological characters.[18][17][19]In 2003, suborderCorophiideawas reestablished for parts of Gammaridea and for the Caprellidea, which was found to be a derived part of the corophiidean clade and became infraorderCaprellida.[18]Then in 2013, new large suborderSenticaudatawas split off from the Gammaridea.[17][20]The Senticaudata, which comprised over half of the known amphipod species.,[14]was divided into six infraorders, one of which was the former Corophiidea (including the former Caprellidea as a parvorder).[17]The dismemberment of Gammaridea was completed in 2017 with the establishment of four new suborders in a six suborder classification:Pseudingolfiellidea, Hyperiidea,Colomastigidea,Hyperiopsidea,Senticaudata andAmphilochidea.[19]At the same time, Ingolfiellidea was split from Amphipoda and reclassified as orderIngolfiellida.[19]The more recent work of Copilaş-Ciocianu et al. (2020) using analysis of molecular data (including 18S and 28S rRNA sequences and the protein coding COI and H3 sequences) found general support for three major groups corresponding to suborders Amphilochidea, Hyperiidea and Senticaudata, but suggests some groups need to move between Amphilochidea and Senticaudata in a taxonomic revision.[21]
The classification listed immediately below, from therankof suborder down to superfamily, represents the traditional division as given in Martin & Davis (2001),[15]except that superfamilies are recognised here[according to whom?]within the Gammaridea. The new classification of Lowry and Meyers (2017) is shown in the cladogram.
| New Amphipoda classification of Lowry and Myers[17][19] | ||||||||||||||||||||||||||||||||||||||||||||||||||||
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Fossil record
editAmphipods are thought to have originated in theLower Carboniferous.Despite the group's age, however, thefossil recordof the order Amphipoda is meagre, comprising specimens of one species from theLower Cretaceous(Hauterivian)Weald Clay(United Kingdom)[22]and 12 species dating back only as far as theUpper Eocene,where they have been found inBaltic amber.[23][24]
Ecology
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Amphipods are found in almost all aquatic environments, fromfresh waterto water with twice thesalinityofsea water[4]and even in theChallenger Deep,the deepest known point in the ocean.[25]They are almost always an important component of aquatic ecosystems,[26]often acting as mesograzers.[27]Most species in the suborder Gammaridea areepibenthic,although they are often collected inplanktonsamples. Members of the Hyperiidea are all planktonic and marine.[6]Many aresymbiontsof gelatinous animals, includingsalps,medusae,siphonophores,colonialradiolariansandctenophores,and most hyperiids are associated with gelatinous animals during some part of their life cycle.[28]Some 1,900 species, or 20% of the total amphipod diversity, live in fresh water or other non-marine waters. Notably rich endemic amphipod faunas are found in the ancientLake Baikaland waters of theCaspian Seabasin.[29]
Thelandhoppersof the familyTalitridae(which also includes semi-terrestrial and marine animals) areterrestrial,living in damp environments such asleaf litter.[30]Landhoppers have a wide distribution in areas that were formerly part ofGondwana,but have colonised parts ofEuropeandNorth Americain recent times.
Around 750 species in 160 genera and 30 families aretroglobitic,and are found in almost all suitable habitats, but with theircentres of diversityin theMediterranean Basin,southeasternNorth Americaand theCaribbean.[31]
In populations found in Benthic ecosystems, amphipods play an essential role in controlling brown algae growth.[27]The mesograzer behaviour of amphipods greatly contributes to the suppression of brown algal dominance in the absence of amphipod predators.[27]Amphipods display a strong preference for brown algae in Benthic ecosystems, but due to removal of mesograzers by predators such as fish, brown algae is able to dominate these communities over green and red algae species.[27]
Morphology
editCompared to other crustacean groups, such as theIsopoda,RhizocephalaorCopepoda,relatively few amphipods areparasiticon other animals. The most notable example of parasitic amphipods are thewhale lice(family Cyamidae). Unlike other amphipods, these are dorso-ventrally flattened, and have large, strong claws, with which they attach themselves tobaleen whales.They are the only parasitic crustaceans which cannot swim during any part of theirlife cycle.[32]
Foraging behaviour
editMost amphipods aredetritivoresorscavengers,[4]with some beinggrazersofalgae,omnivoresorpredators[6]of smallinsectsandcrustaceans.[4]Food is grasped with the front two pairs of legs, which are armed with large claws.[4]More immobile species of amphipods eat higher quantities of less nutritious food rather than actively seeking more nutritious food.[33]This is a type of compensatory feeding.[33]This behaviour may have evolved to minimise predation risk when searching for other foods.[33]Ampithoe longimana,for example, is more sedentary than other species and have been observed to remain on host plants longer.[33]In fact, when presented with both high- and low-nutrition food options, the sedentary speciesAmpithoe longimanadoes not distinguish between the two options.[33]Other amphipod species, such asGammarus mucronatusandElasmopus levis,which have superiorpredator avoidanceand are more mobile, are better able to pursue different food sources.[33]In species without the compensatory feeding ability, survivorship, fertility, and growth can be strongly negatively affected in the absence of high-quality food.[33]Compensatory feeding may also explain the year-round presence ofA. longimanain certain waters.[34]Because algal presence changes throughout the year in certain communities, the evolution of flexible feeding techniques such as compensatory feeding may have beenbeneficial to survival.[34]
Ampithoe longimanahas been observed to avoid certain compounds when foraging for food.[35]In response to this avoidance, species of seaweed such asDictyopteris membranaceaorDictyopteris hoytiihave evolved to produce C11sulfur compounds and C-9 oxo-acids in their bodies as defense mechanisms that specifically deter amphipods instead of deterrence to consumption by other predators.[35]
The incidence of cannibalism andintraguild predationis relatively high in some species,[36]although adults may decrease cannibalistic behaviour directed at juveniles when they are likely to encounter their own offspring.[37]In addition to age, sex may affect cannibalistic behaviour as males cannibalised newly moulted females less than males.[36]
They have, rarely, been identified as feeding on humans; inMelbournein 2017 a boy who stood in the sea for about half an hour had severe bleeding from wounds on his legs that did not coagulate easily. This was found to have been caused by "sea fleas" identified aslysianassid amphipods,possibly in a feeding group. Their bites are not venomous and do not cause lasting damage.[38]
See also
edit
References
edit- ^abLowry J, ed. (2014)."Amphipoda".World Amphipoda database.World Register of Marine Species.Retrieved2014-05-23.
- ^"Amphipoda".Integrated Taxonomic Information System.
- ^"Amphipoda".Oxford English Dictionary(Online ed.).Oxford University Press.(Subscription orparticipating institution membershiprequired.)
- ^abcdefghijkWade, Sam; Corbin, Tracy; McDowell, Linda-Marie (2004). "Class Crustacea".Critter Catalogue. A guide to the aquatic invertebrates of South Australian inland waters(PDF).Waterwatch South Australia.ISBN1-876562-67-6.Archived fromthe original(PDF)on 2009-10-17.
- ^Chan, Brian."Freshwater shrimp (scuds, sideswimmers) – Class: Crustacea, Order: Amphipoda".Fly Fishers' Republic.Archivedfrom the original on 17 January 2020.RetrievedApril 7,2010.
- ^abcdefg"Order Amphipoda".Guide to the marine zooplankton of south eastern Australia.Tasmanian Aquaculture & Fisheries Institute.2008. Archived fromthe originalon 2008-07-20.
- ^abHolsinger, John R."What are amphipods?".Old Dominion University.Archived fromthe originalon July 20, 2011.RetrievedApril 7,2010.
- ^Barnard, J. Laurens; Bowers, Darl E.; Haderlie, Eugene C. (1980). "Amphipoda: The Amphipods and Allies". In Morris, Robert H.; Morris, Robert Hugh; Abbott, Donald Putnam; Haderlie, Eugene Clinton (eds.).Intertidal Invertebrates of California.Stanford University Press.pp. 559–566.ISBN0-8047-1045-7.
- ^Barnard, J. Laurens; Ingram, Camilla L. (1986). "The supergiant amphipodAlicella giganteaChevreux from the North Pacific Gyre ".Journal of Crustacean Biology.6(4): 825–839.doi:10.2307/1548395.JSTOR1548395.
- ^Jamieson, A. J.; Lacey, N. C.; Lörz, A. -N.; Rowden, A. A.; Piertney, S. B. (2013-08-01)."The supergiant amphipod Alicella gigantea (Crustacea: Alicellidae) from hadal depths in the Kermadec Trench, SW Pacific Ocean".Deep Sea Research Part II: Topical Studies in Oceanography.Deep-Sea Biodiversity and Life History Processes.92:107–113.Bibcode:2013DSRII..92..107J.doi:10.1016/j.dsr2.2012.12.002.ISSN0967-0645.
- ^Wolff, T. (1969). "The fauna of Rennell and Bellona, Solomon Islands".Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences.255(800): 321–343.Bibcode:1969RSPTB.255..321W.doi:10.1098/rstb.1969.0014.JSTOR2416857.
- ^Peck, L. S.; Chapelle, G. (2003)."Reduced oxygen at high altitude limits maximum size".Proceedings of the Royal Society B.270(Suppl 2): S166–S167.doi:10.1098/rsbl.2003.0054.PMC1809933.PMID14667371.
- ^abGlazier, Doug (2009). "Amphipoda". In Likens, Gene (ed.).Encyclopedia of Inland Waters.Academic Press. pp. 89–115.doi:10.1016/B978-012370626-3.00154-X.ISBN978-0-12-088462-9.
- ^abWorld Amphipoda Database. Horton, T.; Lowry, J.; De Broyer, C.; et al. (eds.)."Introduction".World Register of Marine Species.Retrieved9 January2023.
- ^abcMartin, Joel W.; Davis, George E. (2001).An Updated Classification of the Recent Crustacea(PDF).Natural History Museum of Los Angeles County.p. 132. Archived fromthe original(PDF)on 2013-05-12.Retrieved2010-04-08.
- ^Vonk, R.;Schram, F. R.(2003)."Ingolfiellidea (Crustacea, Malacostraca, Amphipoda): a phylogenetic and biogeographic analysis".Contributions to Zoology.72(1): 39–72.doi:10.1163/18759866-07201003.
- ^abcdeLowry, J. K.; Myers, A. A. (2013)."A phylogeny and classification of the Senticaudata subord. nov. (Crustacea: Amphipoda)"(PDF).Zootaxa.3610(1): 1–80.doi:10.11646/zootaxa.3610.1.1.PMID24699701.
- ^abMyers, A. A.; Lowry, J. K. (2003). "A Phylogeny and a New Classification of the Corophiidea Leach, 1814 (Amphipoda)".Journal of Crustacean Biology.23(2): 443–485.doi:10.1651/0278-0372(2003)023[0443:APAANC]2.0.CO;2.ISSN0278-0372.S2CID85750244.
- ^abcdLowry, J.K.; Myers, A.A. (2017)."A Phylogeny and Classification of the Amphipoda with the establishment of the new order Ingolfiellida (Crustacea: Peracarida)".Zootaxa.4265(1).Magnolia Press:001–089.doi:10.11646/zootaxa.4265.1.1.PMID28610392.
- ^Horton T (2013). Lowry J (ed.)."Senticaudata".World Amphipoda database.World Register of Marine Species.RetrievedOctober 1,2013.
- ^Copilaş-Ciocianu, Denis; Borko, Špela; Fišer, Cene (2020). "The late blooming amphipods: global change promoted post-Jurassic ecological radiation despite Palaeozoic origin".Molecular Phylogenetics and Evolution.143:106664.Bibcode:2020MolPE.14306664C.bioRxiv10.1101/675140.doi:10.1016/j.ympev.2019.106664.PMID31669816.S2CID196649863.
- ^Edmund A. Jarzembowski; Cédric Chény; Yan Fang; Bo Wang (2020)."First Mesozoic amphipod crustacean from the Lower Cretaceous of SE England".Cretaceous Research.112:Article 104429.Bibcode:2020CrRes.11204429J.doi:10.1016/j.cretres.2020.104429.S2CID213609157.
- ^Bousfield, E. L.; Poinar, G. O. Jr. (1994). "A new terrestrial amphipod from tertiary amber deposits of Chiapas province, Southern Mexico".Historical Biology.7(2): 105–114.Bibcode:1994HBio....7..105B.doi:10.1080/10292389409380448.
- ^The speciesRosagammarusminichiellusfrom the considerably olderLate TriassicLuning Formationof Nevada was originally described as an amphipod, but subsequently reinterpreted as the right half of adecapodtail (Starr, Hegna & McMenamin 2015,The Geological Society of America North-Central Section 49th Annual Meeting[1])
- ^National Geographic (27 March 2012)."James Cameron on Earth's Deepest Spot: Desolate, Lunar-Like".National Geographic Society. Archived fromthe originalon March 28, 2012.Retrieved27 March2012.
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- ^Harbison, G. R.; Biggs, D. C.; Madin, L. P. (1977). "The associations of Amphipoda Hyperiidea with gelatinous zooplankton. II. Associations with Cnidaria, Cteuophora and Radiolaria".Deep-Sea Research.24(5): 465–488.Bibcode:1977DSR....24..465H.doi:10.1016/0146-6291(77)90484-2.
- ^Väinölä, R.; Witt, J. D. S.; Grabowski, M.; Bradbury, J. H.; Jazdzewski, K.; Sket, B. (2008)."Global diversity of amphipods (Amphipoda, Crustacea) in freshwater"(PDF).Hydrobiologia.595(1): 241–255.doi:10.1007/s10750-007-9020-6.S2CID4662681.
- ^Minor, M. A.; Robertson, A. W. (March 5, 2010)."Amphipoda".Guide to New Zealand Soil Invertebrates.Massey University.Archivedfrom the original on 10 May 2010.RetrievedApril 7,2010.
- ^Hobbs, Horton H. III (2003). "Crustacea". In Gunn, John (ed.).Encyclopedia of Caves and Karst Science(PDF).Routledge.pp. 254–257.ISBN978-1-57958-399-6.
- ^Goater, Tim (May 4, 1996)."Parasitic Amphipoda".Interactive Parasitology.Vancouver Island University.Archived fromthe originalon July 14, 2010.RetrievedApril 7,2010.
- ^abcdefgCruz-Rivera, Edwin; Hay, Mark E. (2000). "Can quantity replace quality? Food choice, compensatory feeding, and fitness of marine mesograzers".Ecology.81:201–219.doi:10.1890/0012-9658(2000)081[0201:CQRQFC]2.0.CO;2.hdl:1853/36755.
- ^abCruz-Rivera, Edwin; Hay, Mark E. (2001)."Macroalgal traits and the feeding and fitness of an herbivorous amphipod: the roles of selectivity, mi xing, and compensation".Marine Ecology Progress Series.218:249–266.Bibcode:2001MEPS..218..249C.doi:10.3354/meps218249.hdl:1853/34241.
- ^abSchnitzler, Iris; Pohnert, Georg; Hay, Mark; Boland, Wilhelm (2001). "Chemical defense of brown algae (Dictyopterisspp.) against the herbivorous amphipodAmpithoe longimana".Oecologia.126(4): 515–521.Bibcode:2001Oecol.126..515S.doi:10.1007/s004420000546.PMID28547236.S2CID12281845.
- ^abDick, Jaimie T. A. (1995). "The cannibalistic behaviour of twoGammarusspecies (Crustacea: Amphipoda) ".Journal of Zoology.236(4): 697–706.doi:10.1111/j.1469-7998.1995.tb02740.x.
- ^Lewis, Susan E.; Dick, Jaimie T. A.; Lagerstrom, Erin K.; Clarke, Hazel C. (2010). "Avoidance of filial cannibalism in the amphipodGammarus pulex".Ethology.116(2): 138–146.Bibcode:2010Ethol.116..138L.doi:10.1111/j.1439-0310.2009.01726.x.
- ^Zhou, Naaman (2017-08-08)."Australian teen just 'unfortunate' to be attacked by meat-loving sea fleas".The Guardian.ISSN0261-3077.Retrieved2024-01-22.
