Gammarus setosus 2985538 225687412 2008-07-14T22:16:13Z Rjwilmsi 203434 gen fixes + link/fix date fields in cite templates (explanation [[User:Rjwilmsi#My_correction_of_dates_in_templates|here]]) using [[Project:AutoWikiBrowser|AWB]] {{Taxobox | name = ''Gammarus setosus'' | regnum = [[Animal]]ia | phylum = [[Arthropod]]a | subphylum = [[Crustacean|Crustacea]] | classis = [[Malacostraca]] | ordo = [[Amphipoda]] | familia = [[Gammaridae]] | genus = ''[[Gammarus]]'' | species = '''''G. setosus''''' | binomial = ''Gammarus setosus'' | binomial_authority = [[Dementieva]], 1931 }} '''''Gammarus setosus''''' is a small [[invertebrate]], approximately 1&nbsp;[[centimetre|cm]] in length. Its green-grey body is segmented with several jointed [[appendage]]s and two larger [[antenna (biology)|antennae]] near the head&nbsp;<ref>{{cite book |author=N. A. Campbell & J. B. Reece |year=2001 |title=Biology. Sixth edition |publisher=[[Pearson Education, Inc.]], [[Benjamin Cummings]], [[San Francisco, California]] |id=ISBN 0-805-36624-5 |pages=1175 pp}}</ref>. As with all members of the [[Malacostraca]], ''Gammarus setosus'' has [[mouthparts]] located at the head segments, with their legs branching from each thoracic section, and most of their abdominal sections&nbsp;<ref>{{cite journal |quotes=no |author=V. J. Steele & D. H. Steele |year=1970 |title=Biology of ''Gammarus'' (Crustacea, Amphipoda) in Northwestern Atlantic |journal=[[Canadian Journal of Zoology]] |volume=48 |issue=4 |pages=659}}</ref>. Typically, ''Gammarus setosus'' is found in the benthic sub-tidal or low inter-tidal regions. They can be found in the waters off the coast of [[British Columbia]], but have been observed in nearly all of the world's oceans&nbsp;<ref name="Chav">{{cite journal |quotes=no |author=S. Chavanich & K. A. Wilson |year=2000 |title=Rocky intertidal zonation of Gammaridean Amphipods in Long Island Sound, Connecticut |journal=[[Crustaceana]] |volume=73 |issue=7 |pages=835–846 |url=http://www.springerlink.com/content/r11x84020p626g32/ |doi=10.1163/156854000504840 |format={{Dead link|date=May 2008}}}}</ref>. It has been documented that the different species of [[gammaridea]]n [[amphipod]]s tend to accumulate in zones corresponding to the abundance of the [[algae]] that they eat. In a study involving the inter-tidal distribution of such organisms, it was found that ''Gammarus'' species were more likely to be located in areas where one of their important food sources, ''[[Chondrus crispus]]'' was prevalent&nbsp;<ref name="Chav"/>. In addition to algae, ''Gammarus setosus'' often consumes animal material that has settled to the sea floor. There have been a few cases in which ''Gammarus'' species have preyed upon other small, weak or stressed marine organisms&nbsp;<ref name="Newman">{{cite web |author=R. Newman |title=Freshwater shrimp. A general description of ''Gammarus'' shrimp |url=http://www.bcadventure.com/adventure/angling/bugs/shrimp/shrimp.phtml |accessdate=2005-10-23}}</ref>. However, due to their primarily scavenging nature, they are identified as [[detritivore]]s and serve a crucial role in the diet of other invertebrates, fish and even some whales&nbsp;<ref>{{cite journal |quotes=no |author=B. D. Wisenden, A. Cline & T. C. Sparkes |year=1999 |title=Survival benefit to antipredator behavior in the amphipod ''Gammarus minus'' (Crustacea: Amphipoda) in response to injury-released chemical cues from conspecifics and heterospecifics |journal=[[Ethology]] |volume=105 |pages=407–414 |url=http://www.mnstate.edu/wisenden/pdfs/1999%20gammarus%20survival%20Ethology%20105%20407-414.pdf |doi=10.1046/j.1439-0310.1999.00399.x|format=PDF}}</ref>. Occasionally they are eaten by terrestrial organisms, namely shorebirds and insects that dwell near the ocean&nbsp;<ref>{{cite journal |quotes=no |author=K. Wudkevich, B. D. Wisenden, D. P. Chivers & J. F. Smith |year=1997 |title=Reactions of ''Gammarus lacustris'' to chemical stimuli from natural predators and injured conspecifics |journal=[[Journal of Chemical Ecology]] |volume=23 |pages=1163–1172 |url=http://www.springerlink.com/content/u171616n1g653k3n/?p=c54e8509f6aa45da8dac6f2e6f50aef6 |doi=10.1023/B:JOEC.0000006393.92013.36}}</ref>. Reproduction occurs through a process in which the male carries the female on his back for a length of time, often up to a week. ''Gammarus setosus'' may reproduce many times in a year, which is often the length of their lifespan, generating up to 100 young per episode&nbsp;<ref name="Newman"/>. Relative success of growth and reproduction has been shown to correspond to the length of the photoperiod in a given habitat. ''Gammarus setosus'' can survive in most intensities of light that will occur in their natural environment but are more active at night&nbsp;<ref name="FOSS">{{cite web |publisher=''Gammarus'' |year=2004 |title=A general description of ''Gammarus'' |url=http://www.lawrencehallofscience.org/foss/fossweb/teachers/materials/plantanimal/gammarus.html |accessdate=2005-10-23 |publisher=[[Lawrence Hall of Science]] |date=[[2006-10-03]]}}</ref> or in the darker, lower light intensity of the sea floor&nbsp;<ref>{{cite journal |quotes=no |author=V. J. Steele & D. H. Steele |year=1986 |title=The influence of photoperiod on the timing of reproductive cycles in ''Gammarus'' species (Crustacea, Amphipoda) |journal=[[American Zoologist]] |volume=26 |issue=2 |pages=459–467 |url=http://icb.oxfordjournals.org/cgi/content/abstract/26/2/459 |doi=10.1093/icb/26.2.459 |format=abstract}}</ref>. At temperatures above 20[[Celsius|°C]], reproduction and growth are greatly accelerated and lifespan becomes significantly shorter&nbsp;<ref>{{cite journal |quotes=no |author=T. Neuparth, F. O. Costa & M. H. Costa |year=2002 |title=Effects of temperature and salinity on life history of the marine amphipod ''Gammarus locusta''. Implications for ecotoxicological testing |journal=[[Ecotoxicology (journal)|Ecotoxicology]] |volume=11 |issue=1 |pages=61–73 |url=http://www.ingentaconnect.com/content/klu/ectx/2002/00000011/00000001/00391035 |doi=10.1023/A:1013797130740}}</ref>. Ideally, ''Gammarus setosus'' lives in water around 15°C but can survive in temperatures approximately 10°C above or below this value<ref name="Kruschwitz">{{cite journal |quotes=no |author=Lois G. Kruschwitz |year=1978 |title=Environmental factors controlling reproduction of the amphipod ''Hyalella azteca'' |journal=[[Proceedings of the Oklahoma Academy of Science]] |volume=58 |pages=16–21 |url=http://digital.library.okstate.edu/OAS/oas_pdf/v58/p16_21.pdf}}</ref>. [[Salinity]] is a less important factor, as it has a greater tolerable range and will not vary as much in a given environment. A salinity of 33&nbsp;[[parts per notation|ppt]] is ideal; however, at times ''Gammarus setosus'' are caught in tide pools, where they must survive in water that can reach upwards of 40&nbsp;ppt&nbsp;<ref name="Chav"/>. On the other end of the spectrum, survival is possible in salinity as low as 10&nbsp;ppt&nbsp;<ref name="Kruschwitz"/>. In fact, some ''Gammarus'' species thrive in the very low salinity of [[fresh water|freshwater]] lakes&nbsp;<ref name="Newman"/>. Although not as vital to reproduction or growth, currents in the water column are very important for movement. Floating comprises the primary mode of locomotion, yet they can also swim in short, concentrated bursts. Descriptive of their body orientation while manoeuvring themselves, ''Gammarus'' are often referred to as side-swimmers&nbsp;<ref name="FOSS"/>. ==References== {{reflist}} [[Category:Amphipods]] [[Category:Animals described in 1931]]