Male claspers in clam shrimps (Crustacea, Branchiopoda) in the light of evolution: a case study on homology versus analogy

Tomonari Kaji, Martin Fritsch, Martin Schwentner, Jørgen Olesen, Stefan Richter

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

    19 Citationer (Scopus)
    2 Downloads (Pure)

    Abstract

    Male "clam shrimps" possess highly modified first (and second) trunk limbs for clasping the carapace of females during copulation. Claspers are present in all three clam shrimp taxa (Laevicaudata, Spinicaudata, and Cyclestherida) but despite striking similarities in their morphology and function, the matter of their homology is controversial. In this study, we address the question of the homology and evolution of these structures by comparing the developmental transformation of an unspecialized trunk limb into a clasper. In addition, we study the musculature and the nervous system in trunk limbs and claspers using confocal laser scanning microscopy. We establish that most (but not all) of the various parts of the claspers are homologous between clam shrimp taxa. We suggest that a single pair of claspers was already present in the ground pattern of Diplostraca, probably most comparable to those in Cyclestherida. The claspers, therefore, do not represent a case of analogy.
    OriginalsprogEngelsk
    TidsskriftJournal of Experimental Zoology. Part B: Molecular and Developmental Evolution
    Vol/bind322
    Udgave nummer5
    Sider (fra-til)269-280
    Antal sider12
    ISSN1552-5007
    DOI
    StatusUdgivet - 2014

    Citationsformater