Report on some monstrilloids (Crustacea: Copepoda) from Turkey with description of two new species

Monstrilloid copepods collected during zooplankton surveys carried out in Turkish coastal waters of the southern Black Sea were examined. A total of 3 species were found, of which two are undescribed, one of Cymbasoma Thompson, 1888 and one of Monstrillopsis Sars, 1921. The new species are described, illustrated and compared herein with their congeners. The new Cymbasoma belongs to a small group of species with the fifth leg exopodal lobe bearing two long outer setae and a minute inner seta; it can be distinguished by the shape of the genital somite and the asymmetry of the fifth leg endopodal lobes. The new Monstrillopsis is unique in having an unfused distal spine on the distal segment of the male antennule and paired processes at the base of the genital lappets. We also recorded the presumably widespread Monstrilla grandis Giesbrecht, 1893. The male specimen examined has some remarkable characters, particularly in the swimming legs 1-4, including a reduced, modified inner seta on the second segment of both first leg endopodal rami. Also, the inner seta of the first endopodal segment of legs 1-3 is absent and is present only on leg 4. Males of this species are less common than females; its intraspecific morphological variability compared with previous illustrated reports. The addition of the new species here described brings the number of nominal species of Monstrilloida in the Mediterranean-Black Sea region to 28.