Niphargus schellenbergi

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Niphargus schellenbergi
Systematics
Superordinate : Satchel Shrimp (Peracarida)
Order : Flea crabs (Amphipoda)
Subordination : Gammaridea
Family : Niphargidae
Genre : Niphargus
Type : Niphargus schellenbergi
Scientific name
Niphargus schellenbergi
Karaman , 1932

The cave shrimp Niphargus schellenbergi is one of around 300 species of the genus Niphargus from the order of the amphipods . These species live in the groundwater or in caves. They are blind, transparent white crabs .

Niphargus schellenbergi is named after the Berlin zoologist Adolf Schellenberg , who first described numerous species of Niphargus in the 1930s .

features

More recent analyzes using genetic characteristics have shown that the characteristics used in older identification keys (shape of the rear edge of the three epimeric plates, length ratio of the uropod branches, apical spines of the outer plate of the first maxilla, meshing of the pleopods) are used to differentiate the Niphargus species within the species are highly variable and not sufficient for reliable species differentiation. With many species of the genus published before 2011, it is therefore uncertain which species actually existed.

All Niphargus species are slender and graceful, eyeless animals, they look completely the same when viewed superficially and can only be distinguished under a microscope. Individuals of Niphargus schellenbergi reach a body size of about 5 to 13 millimeters. Niphargus schellenbergi can be distinguished from the related species that occur within its range ( sympatric ) as follows: The outer edge of the scissor limbs of Gnathopods I and II has at least 2 bristles (setae) (in N.aquilex only one, attention: young animals always have only one bristle), the rear edge of the base of the pair of striding legs (peraeopods) VII bears 13 to 18 setae ( fewer in the equilex and fontanus nerves , 12 at most). The palpus of the first maxilla has only 3 setae apically (at the tip) ( 5 to 7 in the fontanus nerve ). Niphargus schellenbergi also tends to be slightly larger than N. equilex .

biology

Niphargus schellenbergi is an obligatory groundwater inhabitant in the water-filled gap system of the soil matrix (interstitial); it is also found in cave waters and at spring outlets. In surface waters it occurs at most washed out or carried away. After being carried into water, it can actively migrate back into the groundwater. The species has a two-year development cycle.

distribution

Niphargus schellenbergi is common in Germany, France, Belgium and the Netherlands. Its distribution area extends from the Pyrenees in the west to the Harz Mountains in the east, in the south to the Alps and in the north to near the North Sea coast. It was first discovered in the Main Valley near Lohr . The species is not rare within its range, in Belgium and Luxembourg it was the most frequently found of the stygobiont species. In a major study of aquifers in Baden-Württemberg, however, it was not given.

Taxonomy and systematics

The species was first described as a subspecies of N. equilex ( Niphargus aquilex subsp. Schellenbergi ), the species rank was only recognized later. After analysis of homologous DNA sequences (the mitochondrial gene COI ( subunit I ) of cytochrome c oxidase , which is routinely used as a marker in DNA barcoding , the species can be differentiated well from the related species of the genus and is actually not closely related to Niphargus aquilex (no sister group ratio ). Within the genus, however, both species belong to a closely related clade.

Individual evidence

  1. ↑ a b c d e Tamara R. Hartke, Cene Fišer, Jennifer Hohagen, Sascha Kleber, Rainer Hartmann, Stefan Koenemann (2011): Morphological and Molecular Analyzes of Closely Related Species In the Stygobiontic Genus Niphargus (Amphipoda). Journal of Crustacean Biology Vol. 31, Issue 4: 701-709. doi : 10.1651 / 10-3434.1
  2. ↑ on the morphological variability and characteristics of Niphargus cf. Cene Fišer, Peter Trontelj, Roman Luštriki, Boris Sket (2009): Toward a unified taxonomy of Niphargus (Crustacea: Amphipoda): a review of morphological variability. Zootaxa 2061: 1-22.
  3. ↑ Patrick Martin, Claude de Broyer, Frank Fiers, Georges Michel, Rose Sablon, Karel Wouters (2009): Biodiversity of Belgian groundwater fauna in relation to environmental conditions. Freshwater Biology 54: 814-829 doi : 10.1111 / j.1365-2427.2008.01993.x
  4. ^ Jean-François Flot & Dieter Weber (2013): Amphipods from caves of the Grand Duchy of Luxembourg. Ferrantia 69: 186-190.
  5. ^ HJ Hahn & A. Fuchs (2009): Distribution patterns of groundwater communities across aquifer types in south-western Germany. Freshwater Biology 54: 848-860. doi : 10.1111 / j.1365-2427.2008.02132.x (open access)
  6. ↑ Ioana Nicoleta Meleg, Valerija Zakšek, Cene Fišer, Beatrice Simona Kelemen, Oana Teodora Moldovan (2013): Can Environment Predict Cryptic Diversity? The Case of Niphargus Inhabiting Western Carpathian Groundwater. PLoS ONE 8 (10): e76760. doi : 10.1371 / journal.pone.0076760 (open access)

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