The Amphipod Crustacea of Ungava Bay, Canadian Eastern Arctic

Abstract

One hundred and fourteen species of amphipods are recorded from Ungava Bay, most of them for the first time from that area; 21 are new for North America, 5 new to science. Many of them show variations from the types, the types having been described from European or Greenland material. Such variations are to be expected in the Ungava Bay material since it represents a large extension in the known distribution of most of the species, and especially in groups such as the Gammarid and Caprellid amphipods which have no pelagic larvae.In two cases (Westwoodilla megalops and Haploops setosa) pairs of amphipod forms known from Europe as separate species are represented in Ungava Bay by forms which cannot without qualification be referred to either European form, showing characteristics of both, and the two species have therefore been brought into synonymy in each case, since the situation does not warrant the establishment of new species for the Ungava Bay specimens. Since in both cases the European forms were very close together in the first place, each of the two species now exists as three geographic variants; subspecific names have not been given to the variants. Evidence is produced in favour of bringing three species of Ischyrocerus (I. latipes, I. assimilis and I. pachtusovi) together into a similar species complex.The distribution of the Ungava Bay amphipods is analysed. They can be divided into (1) an Atlantic group, possibly endemic to the Atlantic, (2) a group whose distribution lies within the subarctic marine zone as here defined, (3) a large group which does not appear to extend south of the subarctic on the western side of the Atlantic but which is widely distributed in the boreal on the eastern side, in the North Sea area, (4) a small number of arctic forms which become less abundant in the subarctic, and (5) species probably of Pacific origin which are not known east of Greenland nor west of the Kara Sea.