Re-examination of the zoeal morphology of Chasmagnathus granulatus, Cyclograpsus lavauxi, Hemigrapsus sexdentatus, and H-crenulatus confirms consistent chaetotaxy in the Varunidae (Decapoda, Brachyura)

The morphology of first stage zoea larvae of four species of grapsoid crabs (viz., Chasmagnathus granulatus Dana. 1851, Cyclograpsus lavauxi H. Milne Edwards, 1853, Hemigrapsus crenulatus (H. Milne Edwards, 1837), and H. sexdentatus (H. Milne Edwards, 1837)) from Argentina and New Zealand was re-examined, Special attention was given to those characters that have been recently recognized to separate larvae of the families Sesarmidae and Varunidae. In all species studied. the setation of several appendages differed from that presented in the original descriptions of the larvae. The new chaetotaxy agrees well with expectations based on a recent taxonomic classification, The shared 2,2 setal pattern on the endopod of the maxilla and the same type of antenna and telson in all of these species., confirm a close phylogenetic relationship among them and their placement within the family Varunidae.