Comparison with previous studies on sponges of the Kara Sea
The Dijmphna sponges of the Kara Sea, collected at the same time and in the same area by Th. Holm (cf. Bergh et al. 1887), were studied by Levinsen (1887). The results of his study are presented in Table 2, left hand column, with currently accepted names given in the right hand column (from the World Porifera Database (WPD), cf. Van Soest et al., 2015). Also in the latter, asterisks indicate whether the species was also collected by the Dutch Polar Expedition. The collection consisted of specimens of 20 sponge species, several of which were collected outside the Kara Sea (deduced from the shallow depth they were collected). Next to collections made by the ‘Dijmphna’ from the drifting ice floe, there were also some shallow-water sponges collected along the way travelling to and leaving from the Kara Sea. Unfortunately, Levinsen (1887) provided only depth data, so the validity of their Kara Sea occurrence is somewhat in doubt because the precise localities are not given. As could be expected, there is a great resemblance in the sponges collected by the Dutch and Danish expeditions, with 9 out of 11 species of the Dutch collection also represented in the Danish collection. The two species not reported by Levinsen, Tetilla sandalina and Lycopodina ruijsi sp. nov. might easily be hiding in the Danish collection under the 13 reported specimens of Tetilla polyura and among the Esperella cupressiformis ‘varieties’ (respectively 27 and 20 specimens of both varieties).
Table 2. Porifera obtained by the ‘Dijmphna’ Expedition to the Kara Sea, collected by Th. Holm, reported and described by G.M.R. Levinsen (1887) (left hand column) with the names corrected on the basis of the present study, and the World Porifera Database (Van Soest et al., 2015, consulted on May 30, 2015) (right hand column). The order of the names follows the treatment in Levinsen’s study. Names with an asterisk were also identified in the present collection.
Further reports on sponges from the Kara Sea are those of Fristedt (1887, 4 species), Hentschel (1929, 3 species), Rezvoi (1924, 12 species), Rezvoi (1931, 6 species), and especially Koltun (1959, 1966, 49 species). The latter author also partially included the results of the previous authors. Lundbeck (1905) renamed Esperella picea sensu Levinsen as Iophon frigidus, and this name is so far retained in the WPD awaiting reexamination. It is assumed here that Iophon frigidus is a junior synonym of Iophon piceum. The reported Kara Sea sponge fauna is here assembled in Table: in the left part the currently accepted names, which number 60 species and in the right part the original combinations and synonyms found in the original studies.
Table 3. Sponges reported from the Kara Sea. The first four columns provide the identities of 60 species under the currently accepted systematics with as references either the World Porifera Database (Van Soest et al., 2015, consulted on May 30, 2015) or the present study. The next three columns provide one or more original genus and species names for the Kara Sea species and their original references.
Almost all of the records of sponges were obtained from more eastern and northern parts of the Kara Sea, which are deeper and/or from inshore localities or from the mouth of the Yenisei. The sponges of the southwestern Kara Sea, where the Dutch Polar Expedition and the ‘Dijmphna’ collected their specimens, are known almost exclusively from these 19th century research activities.