MORPHOLOGICAL VARIABILITY OF PLEUROMAMMA SCUTULLATA (COPEPODA, METRIDINIDAE) FROM WATERS OFF KAMCHATKA

The characteristics of the individual variability of adult males and females of Pleuromamma scutullata Brodsky, 1950 from the eastern part of the Sea of Okhotsk and northeastern part of the Pacific Ocean are discussed. Variability of the shape of cephalothorax and individual limbs was studied. The most variable features proved to be proximal segments of antennules (12 distinct variants), 5(th) pereopods (more than 7 variants of structure), 4(th) pair of swimming legs (3 attributes varied simultaneously), and cushions on cephalothorax. All characteristics varied independently. The length of antennulae on females with cushions on thorax was different from this parameter on females without cushions. Individual variability of males was similar to that of females. Statistical reality of connection between the length of cephalothorax, abdomen, and antennulae in males was observed. This study showed that such features as the shape, size, and direction of teeth in proximal limb Al, the presence of protuberances in thorax, and armed of P5 of females are insufficient for species identification. These features can be used only as additional ones.