Maraenobiotus ishidai, Brancelj & Karanovic, 2015

Brancelj, Anton & Karanovic, Tomislav, 2015, A new subterranean Maraenobiotus (Crustacea: Copepoda) from Slovenia challenges the concept of polymorphic and widely distributed harpacticoids, Journal of Natural History 49 (45), pp. 2905-2928 : 2922-2923

Maraenobiotus ishidai sp. nov.

[ partim.] Maraenobiotus vejdovskyi Mrázek – Ishida 1987: p. 83, fig. 14n.

Type locality

Japan, Hokkaido, Yoichi , 43.13° N, 140.44° E. Habitat data unknown .

Type material

Holotype female illustrated by Ishida (1987) in his figure 14n from the type locality, originally deposited in the author’ s private collection. Current location unknown. [not examined]

Etymology

The species name is dedicated to late Dr Terue Ishida, who discovered this specimen from Japan. The name is a noun in the genitive singular.

Description

Female as illustrated by Ishida (1987) in his figure 14n, as Maraenobiotus veydovskyi Mrázek.

Remarks

This female specimen has truncated principal caudal setae as in Maraenobiotus veydovskyi truncatus Gurney, 1932 , but the caudal rami look very different in shape and size. They are cylindrical in dorsal view and almost twice as long as wide in M. ishidai sp. nov., while the caudal rami in M. vejdovskyi truncatus are almost conical in shape and about as long as wide. Also, in the latter species the distal lateral caudal setae seem to be either much reduced in size or absent, while they are well developed in the former. Finally, the anal operculum is much longer in M. vejdovskyi truncatus than in M. ishidai . There is very little chance that these very disjunct populations, with so vastly different caudal rami and anal operculum, could belong to the same species. In fact, M. ishidai differs so much from the other four species of Maraenobiotus with truncated female caudal setae, which are all European, that we believe there is a strong argument for them to be separate species. Its caudal rami are most similar in shape to those of the Italian M. galassiae sp. nov. (see below) and it may be plausible that the two have shared a recent common ancestor with a wide Holarctic range. Major differences involve the position of the dorsal caudal seta (nearly central in M. galassiae versus close to inner margin in M. ishidai ), as well as the shape and inclination of the posterior margin of the ramus itself (convex and perpendicular to the body axis in M. ishidai versus straight and diagonal in M. galassiae ). Maraenobiotus ishidai differs from M. slovenicus sp. nov. (see above) and M. pescei sp. nov. (see below) in the much longer and cylindrical caudal rami.

Unfortunately, we do not know which appendages illustrated by Ishida (1987) belong to this species, so they cannot be compared to other species from the M. vejdovskyi complex until the holotype has been found and redescribed.