JPR Advance Access originally published online on December 22, 2004
Journal of Plankton Research 2005 27(2):211-219; doi:10.1093/plankt/fbh169
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Journal of Plankton Research Vol. 27 No. 2 © Oxford University Press 2004; all rights reserved
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The first-stage zoeas of Carpilius convexus (Forskål, 1775) and Carpilius maculatus (Linnaeus, 1758) (Crustacea: Decapoda: Brachyura: Xanthoidea: Carpiliidae): an example of heterochrony
1 Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK, 2 Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore 119260 and 3 Department of Chemistry, Biology and Marine Sciences, University of The Ryukyus, 1 Senbaru, Nishihara-Cho, Okinawa 903-0213, Japan
* Corresponding Author: pfc{at}nhm.ac.uk
Received October 15, 2004; accepted in principle November 16, 2004; accepted for publication December 9, 2004; published online December 22, 2004
The first-stage zoeas of Carpilius convexus (Forskål, 1775) and Carpilius maculatus (Linnaeus, 1758) are described and fully illustrated. Both these Indo-West Pacific species exhibited a unique xanthoidean character for the basis of the second maxilliped, which possesses five (arranged 1,1,1,2) setae instead of the expected four (arranged 1,1,1,1). A comparison with the zoeal stages of Carpilius corallinus (Herbst, 1783) as reported by Laughlin et al. (Laughlin et al., 1983) revealed marked differences including the possession of carapace lateral spines (v. absent in C. convexus only), the subterminal setation of the distal maxillule endopod segment with two subterminal setae (versus one subterminal seta in Indo-West Pacific species), the terminal setation of the distal maxillule endopod segment with four setae (versus three setae in C. convexus only), two lateral spines on the telson (versus three in Indo-West Pacific species) and the number of zoeal stages. The first-stage zoeas of the two Indo-West Pacific species appear to have hatched in a more advanced state of development than those of C. corallinus, and the expression of a number of characters has been accelerated (early onset). In fact, the zoeal stages of both Indo-West Pacific species and carpiliid species appear to be abbreviated because the first zoeas are considered to be equivalent to the third-stage zoeas of C. corallinus.