Actiniaria des Südwestatlantik

Abstract

f the German research vessel "Walther Herwig" in 1966, 1968 and 1970/71,708 actinians from 223 stations were collected off the coasts of Argentina and Uruguay. The animals originate from depths between 30 and 1220 m. About ten percent of the individuals collected belong to the family Hormathiidae. A revision is provided for the genus Phelliactis (with four new species: P. caIlicycIus n. sp., P. capricornis n. sp., P, lophohelia n. sp. and P. pelophila n. sp.) and redescriptions of Horrnathia pectinata (HERTWm 1882) and Actinauge Iongicornis (VERRILL 1882). For comparison material of the following species has been studied: Hormathia digitata O. F. MOLLrR 1776 (North Atlantic), H. nodosa FA~RmIUS 1780 (North Atlantic), Actinauge ricbardi (MARION 1882) (off Portugal, North Atlantic), A. verrilIii Me Mt:R~ICH 1893 (North Atlantic), and the following species have been reexamined: A. crassa (WAssrrI~rr 1908), A. granulata CA~LGReN 1928, A. chilensis CAR~GRrN 1959, Phelliactis hertwigi SIMON 1892 (including specimen described as Chondractinia nodosa by G~AweR 1922), P. robzsta CARLGREN 1928a (specimen described as P. hertwigi by CA~LGREr¢ 1942), P. magna (WAsstLIEFF 1908). The following new combinations and synonymizations are given: (a) Paraphelliactis CARLGREN 1928a is a synonym of Phelliactis SIMON 1892. (b) PheIliactis incerta CARL~RrN 1934 iS a synonym of P. hertwigi SIMON 1892. (c) Chondrodactis crassa WASSlLIEFF 1908 belongs to Actinauge VrRRI:~ 1883; Chondrodactis japonica WAss~r~err 1908 probably belongs to Actinoscyphia ST~W~NSON i920 (Actinostolidae). (d) Arnphianthus gigante~s CAaLG~N 1941 belongs to Phelliactis SIMON 1892. (e) "Phelliactis hertwigi" sensu Ca~LGREN 1942 partita is identical with P. robusta. (f) "Chondractinia nodosa" sensu G~AW~ 1922 partita is identical with P. hertwigi. With regard to the taxonomy of higher categories, two results are remarkable: One specimen of Hormathia pectinata bears in its acontia p-mastigophoric nematocysts and thus resembles an Isophelliidae. Aside from the well-known Phelliaetis species with 6, there exist species with 12 pairs of perfect mesenteries; in three species there are specimens with 6 and specimens with 12 pairs of perfect mesenteries. The opinion is forwarded that in spite of many drawbacks which are implied with the study of preserved Actiniaria, the taxonomy can be promoted by combination of traditional anatomical investigations together with an analysis of the cnidom and the variability of diagnostic characters.