Southern African Cumacea- Volume 2

Doctoral Thesis


Permanent link to this Item
Journal Title
Link to Journal
Journal ISSN
Volume Title
The genera Gynodiastylis, Dicoides, Allodiastylis, Sheardia, Ziiiimeriana, and Hali ana gen. nov. are removed from the ui as tyl id ae and pl aced in the reinstated family Gynodi astyl i dae Stebbing, 1912. The farnily is confined to sha 11 ow waters of the Indo-west·-Paci fi c Region. In southern Africa the Gynodiastylidae are represented by seven species in three genera. One of the genera (Haliana) is new, and so are all of the species, Haliana eckloniae, Dicoides siphonatus, Gynodiastylis sulcatus, G. curvirostris, G. profundus, G. lineatus and G. fulgidus. All are described and figured. The southern African Diastylidae are represented by seventeen species in six genera. Two further species are known from the Cape Basin. Sixteen species are described and figured. Vemakylindrus is raised from subgeneric to' generic status and the genus Adiastylis is reinstated to accommodate many species intermediate between Makrokyl i ndrus and Diastyl is. TvJe l ve species are new, namely Die formosae, D. platytelson, Vemakylindrus stebbingi, Makrokylindrus spinifer, M. deinotelson, M. mundus, M. bicornis, Adiastylis aculeatus, Diastylis namibiae, Leptostylis gilli, L. attenuatusand L. faurei. Keys are given to the southern African Gynodiastylidae and Diastylidae, the genera of the two families, Dicoides, the species of Gynodiastylis described since 1946, Die, Vemakylindrus, Makrokylindrus, Adiastylis and the species of Diastylis and Leptostylis from the southern hemisphere. The distribution of the Diastylidae is discussed; the family appears to predominate in temperate latitudes and occurs widely at all depths below the intertidal zone. Although the southern African Diastylidae are mainly deep-water forms, there are a few very successful shallow-water species, including Diastylis algoae, which is the most abundant of all local cumaceans, as well as accounting for more than 75% of the individuals of diastylid from southern Africa. The species diversity is low and the rate of endemism appears to be 100%.