ABSTRACT
The Scyllaridae (slipper lobsters) is a highly distinctive family, recognized for millennia. The higher taxonomy of the family is reasonably settled due particularly to the contributions of Dr. Lipke Holthuis. Eighty-five scyllarid species in 20 genera have been identified to date, divided among four subfamilies. Further species will inevitably be described, particularly in the Scyllarinae, which includes well over half the scyllarid species and is distributed throughout a greater range of latitudes and depths than the other three subfamilies. Scyllarids are closely related to the Palinuridae and Synaxidae. The three families (together, the Achelata) share numerous characters, most notably their phyllosoma larvae, that separate the Achelata from all other Decapoda. The platelike antennal flagellum of slipper lobsters distinguishes them clearly from palinurids and synaxids that possess whiplike antennae. Characters, such as the presence of multiarticulate exopods on the maxillipeds of the subfamilies Ibacinae and Arctidinae and their absence from the Theninae and Scyllarinae, represent well-defined differences between the higher taxa. Relationships within the four subfamilies are less clear and the primitive or derived nature of some morphological characters remains to be resolved. Thirteen new genera have recently been named in the Scyllarinae, by far the largest and least known of the slipper lobster subfamilies. More information is necessary to verify this division. Fossil and morphological evidence, the distribution of extant species, their developmental characteristics, ecology, and biology suggest the Scyllaridae are Tethyan in origin and have evolved with the development of the major oceans. Scyllarids appear to have undergone recent radiations into shallow, shelf, and deep water habitats. The family is pantropical and it is most unlikely that it, or any group within it, is the relict of a formerly more widespread population. Some distinctive genera are, however, characteristic of certain regions. The evolution of scyllarid morphology and behavior appears to have favored cryptic lifestyles. Larval durations in most (but not all) scyllarid species are shorter than in palinurids, and there is evidence of abbreviated development in some continental shelf species, indicating specialization.
