Eine isolierte population von Pseudeuphausia latifrons (Crustacea: Euphausiacea) im Persischen Golf

During the expedition of RV “Meteor” in 1964/1965 a population of Pseudeuphausia latifrons (G. O. Sars, 1883) was found in the Persian Gulf; this population is isolated and morphologically different from a population of the same species in the Arabian Sea. The adults of the Persian Gulf population are between 7 and 16 mm long which means that they are considerably larger than those found elsewhere. Morphological differences of the copulatory appendages of the male specimens from the Persian Gulf can only partly be regarded as allometric, which may be due to the abnormal length of these specimens. It is possible that isolation and the particular ecological conditions in the Persian Gulf have led to genetic changes in this population so that it can be regarded as a distinct geographical variation. Comparative analysis has shown that Pseudeuphausia colosii Torelli, 1934, described from the Red Sea, is synonymous with Pseudeuphausia latifrons (G. O. Sars, 1883).