| Popis: |
A new small species of oncaeid copepod, Oncaea cristata, is described from the mesopelagic zone of the Red Sea. The species is characterized by a very small outer distal spine on the endopods of swimming legs 2 and 3, being shor- ter than the terminal conical projection on the distal segment. Females of an oncaeid species sharing this distinct morpho- logical character were described by Shmeleva (1969) from the Adriatic Sea under the name O. ovalis. However, the original description of O. ovalis by Shmeleva (1966), based on male specimens from the same area, exhibits distinct differences in the proportional spine lengths on swimming legs 2 and 3, suggesting that two different species may have been described under this name. Since the type material of O. ovalis is no longer extant, new material from the mesopelagic zone in the southern Adriatic Sea was examined during the present study in an attempt to clarify the taxonomic confusion surrounding ovalis-type oncaeids. Both sexes of three different ovalis-type oncaeids were found in the Adriatic, which are distinguished by distinct differences in endopodal spine lengths on legs 2 and 3: ovalis-type 1 is assigned to O. ovalis Shmeleva, 1966, based on (1) outer distal spine longer than the terminal conical projection on legs 2 and 3, and (2) outer distal spine equal in length to the distal spine on leg 2; ovalis-type 2 is characterized by very short outer distal spines on the endopods of leg 2 and 3, being shorter than the terminal conical projection in both legs and is described here as a new species, O. crypta sp. nov. being conspecific with O. ovalis sensu Shmeleva (1969) (female only); ovalis-type 3 is similar to the male of O. bathyalis sensu Shmeleva (1969), however, differences in the endopodal spine lengths between the two sexes in Shmeleva´s (1968) original description of the female and her subsequent redescription of both sexes in 1969 render it virtually impos- sible to make any positive statement as to the identity of genuine O. bathyalis |
