Final stage phyllosoma of Galearctus sp. (Decapoda: Scyllaridae) from the Coral Sea

Larval stages are known for only four out of eight Galearctus Holthuis, 2002 (Crustacea: Scyllaridae) species, a slipper lobster genus widely distributed throughout the Indo-Pacific region. DNA barcoding analyses of phyllosomae collected from the Coral Sea by the Australian Institute of Marine Science suggest the presence of two new genetic clades in the area, for which larvae cannot be discriminated morphologically. The last instar larva of an unknown species of Galearctus is described and illustrated in detail here. It is possible that this larval material may be assigned to G. umbilicatus, the only species of the genus lacking a DNA barcode. Morphological analyses and a literature review allowed the re-evaluation of previous Galearctus larval studies, identifying several misidentifications and inconsistencies. Further morphological and molecular revision of adult Galearctus species is required to confirm larval identities, but the results presented here indicate that the diversity of Galearctus may be underestimated.