Research project: Larval-fish and adult systematics of the percoid fish genera Lobotes, Hapalogenys and Datnioides
- Start date:
- Australian Museum Fellowship
The percoid genera Lobotes Cuvier (Tripletails), Datnioides Bleeker (Tigerperches) and Hapalogenys Richardson (Velvetchins) have long perplexed ichthyologists. Lobotes (2 species) are relatively large fishes found worldwide in warm, mostly coastal waters. Datnioides (5 species) are moderate-sized fishes of estuaries and freshwaters from India and South-East Asia to New Guinea. Hapalogenys (7 species) are moderate-sized fishes of coastal waters that range from Japan and the central Indian Ocean to north-western Australia.
Traditional classifications often placed Lobotes and Datnioides as the sole genera of Lobotidae, but character evidence for a close relationship has been scant, and some classifications treat Datnioides as incertae sedis. Traditionally, Hapalogenys has been placed in Haemulidae, a placement not supported by characters definitive for that family or that associate it with other families. But, perhaps for the lack of any other clear relationships, Hapalogenys is sometimes placed in a separate family. Although no previous classifications have proposed a relationship between Hapalogenys, Lobotes and Datnioides, the remarkable similarity of their larvae, particularly in head spination, pigmentation, early development of posteriorly-placed pelvic fins and general body shape, led us to examine the hypothesis that they were related.
Here, we provide additional evidence from adult and larval morphology that supports the hypothesis of a monophyletic Lobotidae composed of the three genera: in larvae, most convincingly, sculpting on the skull; and in adults, tooth replacement mode (Hilton and Beemis 2005), tooth arrangement and dorsal gill-arch morphology. Furthermore, despite their traditional placement among percoids, there is growing evidence for a basal position of lobotids among an expanded Acanthuroidei.
Dr Jeff Leis , Senior Fellow