The Morphological Radiation of Setae in the Cladocera (Crustacea) and Their Potential for Morphogenesis

✍ Scribed by Nikolai N. Smirnov; Alexey A. Kotov

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 938 KB
• Volume: 95
• Category: Article
• ISSN: 1434-2944
• DOI: 10.1002/iroh.201011244

✦ Synopsis

Abstract

The present review seeks to demonstrate the presence of an inherent biological tendency for the modification of form in cladoceran setae. We present a comparative description of the setal equipment of the cladoceran antenna I, antenna II, maxilla I, maxilla II, each thoracic limb, the carapace valves, and the postabdomen. We revealed significant differences between planktonic and benthic species of the Cladocera. Also our analysis stresses the great differences between the “daphniid” line (Daphniidae + Moinidae) and the “chydorid” line (all other families) of the order Anomopoda.

Comments on cladoceran limb evolution are made, and some general conclusions concerning the major tendencies of setal evolutionary transformations are drawn. The morphological range of homologous structures in different species is generally wide, from an undifferentiated seta to either its disappearance or to enlargement, heavy chitinization, and specialization. Special issues, such as parallelisms, oligomerization, asymmetry, abnormalities, and conjugated morphogenesis are discussed. It is assumed that, having been originated, if not eliminated, these modifications either find some adaptive use in the process of radiation at the next level – adaptive radiation – or restrict the niches of specialized groups, or just remain ecologically neutral and then give rise to a series of similar species. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)