Revision of the Afrotropical land snail genus Avakubia Pilsbry, 1919, with description of Pseudavakubia gen. n. and eleven new species (Gastropoda: Pulmonata: Streptaxidae)

A. J. de Winter, N. Vastenhout

Abstract


A revision of the world-wide available material of the Afrotropical streptaxid subgenus Avakubia Pilsbry, 1919, prompted the change in status to independent genus and the detection of undescribed species. In ad­dition to the two earlier described species, A. avakubiensis (Pilsbry, 1919) and A. acuminata (Thiele, 1933), the genus Ava­kubia is found to embrace at least seven new species, viz., A. crystallum de Winter, sp. n. from Gabon; A. fru­ticicola de Winter & Vastenhout, sp. n., A. semenguei de Winter & Vastenhout, sp. n. and A. subacuminata de Winter & Vastenhout, sp. n. from Cameroon; A. ortizdezarateorum de Winter & Vastenhout, sp. n. and A. biokoensis de Winter & Vastenhout, sp. n. from Bioko I., Equatorial Guinea, and A. occidentalis de Winter, sp. n. from Ghana. Of some other potentially new Avakubia species insuffi­cient ma­terial is available to allow a formal description. For a West African radiation with remarkably si­milar shells, but differing from true Avakubia in pro­toconch and teleoconch cha­racters, a new genus Pseudavakubia de Winter & Vastenhout, gen. n. is erected with four new species, viz., P. atewaensis de Winter, sp. n., P. majus de Winter & Vastenhout, sp. n. (type species), P. ghanaensis de Winter, sp. n., and P. liberiana de Winter, sp. n. Avakubia ava­kubiensis has been reported in the literature from Uganda to Liberia, a range of 4750 km. Study of this ma­terial restricts the range of this species to the eastern Democratic Republic of the Congo and Uganda, the remaining records were found to refer to five other species of Avakubia or Pseudavakubia described in this paper, each with a much more restricted range. The genital anatomy of both Avakubia and Pseudavakubia is found to deviate from most other members of the family Streptaxidae in the absence of chitinous spines in the penis. Both genera are ovoviviparous. In the penis of a specimen of A. acuminata a sper­matophore-like structure was found. Some aspects of the ecology of these rainforest-dwelling snails are de­scribed. An identification key to the species of Avakubia and Pseudavakubia is provided.

To cite this paper: de Winter, A.J. & Vastenhout, N. 2013. Revision of the Afrotropical land snail genus Avakubia Pilsbry, 1919, with description of Pseudavakubia gen. n. and eleven new species (Gastropoda: Pulmonata: Streptaxidae). African Invertebrates 54 (2): 605–663.

Published electronically: 31 December 2013
urn:lsid:zoobank.org:pub:C62485BE-43A5-4499-B559-E8762700CD8E


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