Revision of the genus Leucocythere Kaufmann, 1892 (Crustacea, Ostracoda, Limnocytheridae) with the description of a new species and two new tribes
Danielopol, D.L.; Martens, K.; Casale, L.M. (1989). Revision of the genus Leucocythere Kaufmann, 1892 (Crustacea, Ostracoda, Limnocytheridae) with the description of a new species and two new tribes. Bull. K. Belg. Inst. Nat. Wet. 59: 63-94
In: Bulletin. Institut Royal des Sciences Naturelles de Belgique. Mededelingen. Koninklijk Belgisch Instituut voor Natuurwetenschappen. KBIN: Brussel. ISSN 0368-0177, meer
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| Auteurs | | Top |
- Danielopol, D.L.
- Martens, K., meer
- Casale, L.M.
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| Abstract |
The main aim of the present contribution is to provide an unequivocal diagnosis of the genus Leucocyhtere. It appeared, however, that this could only be effected when embodied in a broader taxonomic framework. The subfamily Limnocytherinae is thus divided into four tribes: Limnocytherini, Dinarocytherini, Cytheridellini and Leucocytherini and diagnoses are provided for these taxa. The latter two are new to science while the rank of Dinarocyhterini was changed from subfamily to tribe. Three genera are lodged in the Leucocytherini: Leucocythere Kaufmann, 1892, Potamocythere Schornikov, 1986 and Ovambocythere Martens, 1989. The former, nominate, genus is characterized and its type species, L. mirabilis, is extensively redescribed. A comparative description of a limnocytheridinid with a somewhat similar appearance, Limnocythere (Limnocytherina) sanctipatricii, is offered. A second species of Leucocythere, L. algeriensis nov. sp., is described from a temporary pool in Algeria. L. baltica (Diebel) is retained as a third species in the genus. A large number of fossil records is reassessed. Most of the Asian fossils, previously assigned to Leucocythere, do not belong in this genus and a revision of their status appears urgent. Some remarks on the validity and position of Leucocytherella are also offered. L. mirabilis is a cold-stenothermic species, with a preference for oligotrophic waters and fine graine sediments. Its status in Europe can at present best be described as endangered, due to rapid degradation of suitable habitats. L. algeriensis nov. sp. and Ovambocythere milani Martens are probably both capable of producing dry resistant stages. This is thus far unique in Cytherids, but the exact taxonomic distribution of this feature remains as yet unknown. Some comments on the phylogeny and historical biogeography are presented. Leucocythere appears to be the more advanced group in the Leucocytherini, the other two genera show more plesiomorphic character states. It is here postulated that the three genera evolve by vicariance from a more widely spread ancestor: Leucocythere in Europe, Potamocythere in Asia and Ovambocythere in Africa. L. algeriensis from northern Africa is doubtlessly from Paleartic stock and its speciation from L. mirabilis must have occured fairly recently. A number of morphological peculiarities of L. mirabilis are discussed with special attention for the carapace and for those soft parts that are used for the mating process. In spite of the fact that many of the peculiarities appear maladaptive at first glance, it must be stressed that L. mirabilis thus far maintained itself very well in its environment, until recent anthropogenic pollution caused its extinction in many localities. |
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