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The Scheme

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Cave stream, Swildon's Hole, Mendips
(photo courtesy of William Kromhout)

The hypogean (subterranean) Crustacea recording scheme is a small scheme dealing with the subterranean macro-Crustacea found in the groundwater and aquatic cave habitats of the British Isles, including Ireland. The scheme only encompasses the larger Crustacea specifically evolved to exist in underground aquatic habitats (stygobites). Adaptations to the underground aquatic environment typically involve a lack of pigment (i.e. specimens are white in colour), a lack of eyes and over-development of antennae and legs. Most species are also very small and have a thin body shape for squeezing between small water-filled crevices in underground rock strata and water-logged gravels.

Specimens of the ubiquitous epigean (surface-dwelling) freshwater shrimp Gammarus pulex are often recorded in caves but are usually washed in from the surface, although some isolated stygophilic populations have been recorded. In Ireland a similar case exists with Gammarus duebeni celticus. Both of these species are not included in the scheme. 

The scheme also does not cover the micro-Crustacea (Copepoda, Ostracoda, Cladocera etc.) Amongst the micro-crustaceans there are several species that have been recorded from cave and groundwater habitats but it is thought that the copepod Acanthocyclops sensitivus is the only true sygobitic copepod in Britain. Proudlove et. al. (2003) lists the various micro-Crustacea and discusses their distribution and hypogean status. This same publication also discusses the occurrence of Gammarus species underground.

The eleven larger stygobitic Crustacea recorded from Britain and Ireland and covered by the recording scheme are listed below.

Superorder Order Family Species Authority
Syncarida Bathynellacea Bathynellidae Antrobathynella stammeri Jakobi, 1954
      Bathynella natans Vejdoysky, 1882
Peracarida Amphipoda Niphargidae Niphargus aquilex Schiődte, 1855
      Niphargus fontanus Bate, 1859
      Niphargus glenniei Spooner, 1952
      Niphargus kochianus Bate, 1859
      Niphargus irlandicus
Schellenberg, 1932
      Niphargus wexfordensis
Karaman, Gledhill & Holmes, 1994
      Microniphargus leruthi
Schellenberg, 1934
Peracarida Amphipoda Crangonycitidae Crangonyx subterraneus Bate, 1859
Peracarida Isopoda Asellidae Proasellus cavaticus Leydig, 1871 sensu Henry, 1970 

References and further reading

» Download the references and further reading list – Doc-File, 54.5 KB