Monstrilloids (Crustacea: Copepoda) from the Mediterranean Sea (Northern Adriatic Sea), with a description of six new species

Monstrilloid copepods collected during zooplankton surveys carried out over several years (2009–2016) in the Gulf of Trieste, northern Adriatic Sea, were examined. A total of seven species were found, of which six are undescribed, five of Cymbasoma and one of Monstrilla. These new species are described, illustrated and compared herein with its known congeners. Two of them are related to the C. rigidum species complex. One of these species is described based on both the male and the female; sexes were linked by identical details of the cephalic structure and the antennulary armature. Two previous reports of females attributed to C. tumorifrons from the Mediterranean relate to specimens that in fact belong to a new species, C. mediterranea. The most abundant species was M. grandis, which had a remarkable aggregation around the Trieste harbour in 2015. Male and female specimens of this assumedly widespread species were examined and the observed intra-specific morphological variability is reported and...