LARVAE OF 5 FISH FAMILIES WITH PATTERN 10 OF THE RAMUS-LATERALIS-ACESSORIUS NERVE (ARRIPIDAE, GIRELLIDAE, KYPHOSIDAE, MICROCANTHIDAE AND SCORPIDIDAE) - RELEVANCE TO RELATIONSHIPS

We describe the larvae of five temperate Australian fishes from five p ercoid families considered to form part of a monophyletic group becaus e they share the uncommon pattern 10 of the facial nerve ramus lateral is accessorius (RLA-10). An attempt was made to assess to what extent the larval characters described for these species-Arripis trutta (Arri pidae), Girella tricuspidata (Girellidae), Kyphosus sp. (Kyphosidae), Atypichthys strigatus (Microcanthidae) and Scorpis (lineolata?) (Scorp ididae)-support a close relationship among these RLA-10 families. Larv ae of the five species share similarities in body form, head spination , fin formation and pigment pattern, and generally fit the ''distincti ve larval form'' previously described for ''girelloid'' RLA-10 familie s. Although such similarities are consistent with a close relationship among these families, most attributes of the distinctive larval form are also present in larvae of a number of non RLA-10 percoid families, notably the Pomatomidae. Based only on larval characters, one could h ypothesize that most RLA-10 percoid families, including the Dichistiid ae (Leis and van der Lingen, 1997), form part of a larger group that a lso includes non RLA-10 families such as the Pomatomidae. Alternativel y, the ''distinctive larval form'' in Pomatomus and some other non RLA -10 families could have been acquired independently. However, since we could not show that any of the attributes of the distinctive larval f orm constitute synapomorphies, nor is the sister group of the RLA-10 f amilies known, neither of these alternatives could be tested during th is study. Larval characters alone cannot at present resolve the relati onships of the RLA-10 families.