Branchinecta gaini

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Branchinecta gaini
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Branchiopoda
Order: Anostraca
Family: Branchinectidae
Genus: Branchinecta
Species: B. gaini
Binomial name
Branchinecta gaini
Daday, 1910

Branchinecta gaini is a species of fairy shrimp from Antarctica and Patagonia. It is the largest freshwater invertebrate in Antarctica, at 16 mm (0.63 in) long. It lives on bacteria and other organisms, surviving the winter as resting eggs.

Distribution[edit]

B. gaini is found from "half-way down the Antarctic Peninsula" northwards, including southernmost South America and subantarctic islands such as South Georgia and the South Orkney Islands.[1] It is the only fairy shrimp on mainland Antarctica, where it is "rather widespread on the Antarctic Peninsula";[2] records of "Branchinecta granulosa" from Antarctica are all misidentifications of B. gaini.[3] In the South Shetland Islands, B. gaini has been recorded from the lakes on the ice-free Byers Peninsula of Livingston Island (alongside Boeckella poppei and the benthic cladoceran Macrothrix ciliata),[4] in Lake Wujka, and in Sombre Lake on Signy Island (alongside Boeckella poppei and the carnivorous Parabroteus sarsi).[5]

The only known fossil records of the genus Branchinecta are of B. gaini; its eggs have been found in mid to late Holocene (4,200 BP)[6] lake deposits on James Ross Island, on the east side of the Antarctic Peninsula.[7] B. gaini no longer occurs on James Ross Island, presumably because the lakes are unfrozen for too short a period for B. gaini to complete its life cycle.[7] The egg cases were found to be most abundant during the Holocene climatic optimum, indicating that cyanobacterial mats must have been present in the lake then.[8] Eggs dating from 5,500 BP have also been found on Signy Island, where the species persists.[6]

Description[edit]

Branchinecta gaini can reach a total length of 16 millimetres (0.63 in), making it the largest freshwater invertebrate in Antarctica.[9] It uses its trunk limbs to scrape food from the substrate.[10]

Ecology and life cycle[edit]

Branchinecta gaini feeds on epiphytes in bacterial mats, and on the mats themselves.[8] The gut contents of B. gaini are dominated by green algae, hyphae and remains of other B. gaini individuals.[10] They live for over six months, and produce resting eggs which can survive the winter, when the lakes are frozen.[11] Although B. gaini often coexists with the copepod Boeckella poppei, they are rarely seen in close contact. They may be in competition for food, or B. gaini may feed on the nauplii of the copepod.[11]

B. gaini can be quite abundant, dominating the crustacean biomass in freshwater bodies in the South Orkney and South Shetland islands.[10]

The dispersal of B. gaini between lakes is probably passive, with the most likely dispersal vectors being birds; branchiopod eggs swallowed by seabirds, even if still being brooded by the mother, can survive passage through the bird's digestive system.[1]

Taxonomic history[edit]

Branchinecta gaini was first described by the Hungarian biologist Eugen von Daday de Deés (also called Jenö Daday or Jenö Daday de Dées) in 1910 based on material collected from Petermann Island by the Deuxième Expédition Antarctique Française aboard the Pourquoi Pas ?, captained by Jean-Baptiste Charcot;[12] the specific epithet commemorates the French algologist Louis Gain, who was responsible for preserving the specimens from that expedition.[13]

References[edit]

  1. ^ a b T. C. Hawes (2009). "Origins and dispersal of the Antarctic fairy shrimp". Antarctic Science 21 (5): 477–482. doi:10.1017/S095410200900203X. 
  2. ^ Luc Brendonck, D. Christopher Rogers, Jorgen Olesen, Stephen Weeks & Walter R. Hoeh (2008). Global diversity of large branchiopods (Crustacea, Branchiopoda) in freshwater. In Estelle V. Balian, Christian Lévêque, Hendrik Segers & Koen Martens. "Freshwater Animal Diversity Assessment". Hydrobiologia 595: 167–176. doi:10.1007/s10750-007-9119-9. ISBN 978-1-4020-8258-0. 
  3. ^ P. J. A. Pugh, H. J. G. Dartnall & S. J. McInnes (2002). "The non-marine Crustacea of Antarctica and the Islands of the Southern Ocean: biodiversity and biogeography". Journal of Natural History 9: 1047–1103. doi:10.1080/00222930110039602. 
  4. ^ Warwick F. Vincent, John E. Hobbie & Johanna Laybourn-Parry (2008). "Introduction to the limnology of high-latitude lake and river ecosystems". In Warwick F. Vincent & Johanna Laybourn-Parry. Polar Lakes and Rivers: limnology of Arctic and Antarctic aquatic ecosystems. Oxford University Press. pp. 1–23. doi:10.1093/acprof:oso/9780199213887.001.0001. ISBN 978-0-19-921388-7. 
  5. ^ Kirsten S. Christoffersen, Erik Jeppesen, Daryl L. Moorhead & Lars J. Tranvik (2008). "Food-web relationships and community structures in high-latitude lakes". In Warwick F. Vincent & Johanna Laybourn-Parry. Polar Lakes and Rivers: limnology of Arctic and Antarctic aquatic ecosystems. Oxford University Press. pp. 269–289. doi:10.1093/acprof:oso/9780199213887.001.0001. ISBN 978-0-19-921388-7. 
  6. ^ a b John A. E. Gibson & Ian A. E. Bayly (2007). "New insights into the origins of crustaceans of Antarctic lakes" (PDF). Antarctic Science 19 (2): 157–164. doi:10.1017/S0954102007000235. 
  7. ^ a b Ole Bennike, Klaus P. Brodersen, Erik Jeppesen & Ian R. Walker (2004). "Aquatic invertebrates and high latitude paleolimnology". In Reinhard Pienitz, Marianne S. V. Douglas & John P. Smol. Long-term environmental change in Arctic and Antarctic lakes. Volume 8 of Developments in paleoenvironmental research. Springer. pp. 159–186. ISBN 978-1-4020-2125-1. 
  8. ^ a b Dominic A. Hodgson, Peter T. Doran, Donna Roberts & Andrew McMinn (2004). "Paleolimnological studies from the Antarctic and Subantarctic Islands". In Reinhard Pienitz, Marianne S. V. Douglas & John P. Smol. Long-term environmental change in Arctic and Antarctic lakes. Volume 8 of Developments in paleoenvironmental research. Springer. pp. 419–474. ISBN 978-1-4020-2125-1. 
  9. ^ T. C. Hawes (2008). "Feeding behaviour in the Antarctic fairy shrimp, Branchinecta gaini". Polar Biology 31: 1287–1289. doi:10.1007/s00300-008-0494-0. 
  10. ^ a b c J. C. Paggi (1996). "Feeding ecology of Branchinecta gaini (Crustacea: Anostraca) in ponts of South Shetland Islands, Antarctica". Polar Biology 16 (1): 13–18. doi:10.1007/BF01876824. 
  11. ^ a b Agnieszka Pociecha & Henri J. Dumont (2008). "Life cycle of Boeckella poppei Mrazek and Branchinecta gaini Daday (King George Island, South Shetlands)". Polar Biology 31: 245–248. doi:10.1007/s00300-007-0360-5. 
  12. ^ E. Daday de Deés (1910). "Quelques phyllopodes anostracés nouveaux. Appendice a la monographie systématique des phyllopodes anostracés". Annales des Sciences Naturelles: Zoologie. 9th series 12: 241–264. 
  13. ^ Hans G. Hansson. "Biographical Etymology of Marine Organism Names". Göteborgs Universitet. Retrieved October 16, 2010.