Evolutionary morphological development of the cladocera of the superfamily sidoidea and life strategies of crustaceans of continental waters

Abstract

AbstractComparative‐morphological analysis of the structure of the Cladocera of the superfamily Sidoidea ( = Ctenopoda) comprising the families Sididae and Holopediidae, compared with representatives of other groups: Chydoroidea (=Anomopoda), Limnadiiformii (= Conchostraca), Polyphemiformii (Polyphemiformes (= Onychopoda) and Leptodoriformes (= Haplopoda)) and Branchipodiones (Branchipodiformes (= Anostraca) and Triopiformes (= Notostraca)) is made. The main parameters and structures important in functional‐morphological and ecological aspects are considered: including dimensions of the body, its form and proportions, the complex eye, swimming antennae, body covers, thoracic limbs, the postabdomen. In distinction from all crustaceans under consideration in the Sididae and the Polyphemiformii organs contributing to rapid manoeuvrable swimming, soaring and good orientation in the environment received the prevailing development in evolution: antennae, stabilizing appendages of the posterior part of the body, the eye, etc. All this predetermined elaboration of the life strategy in these forms mainly aimed, especially in the Sididae, at active avoidance of predation combined with elements of passive protection (imperceptibility attained by various methods). Representatives of the Sididae, including planktonic Diaphanosoma, well survive in water bodies with the intensive press of predation. All others, including the Holopediidae, clearly possess the passive protection (development in localities inaccessible to predators, imperceptibility, protective structures on the body surface, etc.).