PHYLOGENETIC-RELATIONSHIPS AMONG ATHERINIFORM FISHES (TELEOSTEI, ATHERINOMORPHA)

We present evidence from adult and larval morphology for the monophyly and relationships of Atheriniformes, using other atherinomorphs, mugi lids and acanthomorph fishes as outgroups. Atheriniformes is diagnosed by ten characters (larval: short preanal length, single mid-dorsal ro w of melanophores; adult: vomerine ventral face concave, long Al muscl e tendon to lacrimal, two anterior infraorbital bones, pelvic-rib liga ment, pelvic medial plate not extended to anterior end, and second dor sal-fm spine flexible). We recognize six families within the order, th e hierarchical relationships among which are: (Atherinopsidae (Notoche iridae (Melanotaeniidae (Atherionidae (Phallostethidae, Atherinidae))) )). Other major conclusions include: (1) Atherinopsidae (Menidiinae, A therinopsinae) is diagnosed by 20 characters (e.g. ethmomaxiliary liga ment attached to palatine dorsal process, ventral postcleithrum with t wo dorsal rami); (2) Melanotaeniidae (Bedotiinae (Melanotaenimae (Telm atherinini, Pseudomugilini))) is diagnosed by six characters (e.g. abs ence of second dorsal-fin spine, sexual dimorphism in body colour and median-fin development, greater body depth); (3) Dentatherina is in Ph allostethidae; (4) Atherinidae (Atherinomorinae (Craterocephalinae, At herininae)) is diagnosed by three characters (lacrimal notch, ventral postcleithrum between first and second pleural ribs, pelvic ventral sp ine); 15) Atherinidae and Phallostethidae form the Atherinoidea clade diagnosed by seven characters (e.g. interopercle dorsal process absent , dorsal wings of urohyal absent, ventral postcleithrum laminar, pelvi c medial plate extended to anterior end, presence of anal plate). Bedo tia, Rheocles, and melanotaeniines are shown to be derived within athe riniforms rather than the plesiomorphic sister groups to a paraphyleti c 'atherinoid' group. We also demonstrate that groups traditionally pl aced in Atherinidae (Menidiinae, Atherininae, Atherioninae, etc.) comp rise a paraphyletic assemblage. (C) 1996 The Linnean Society of London