Fishes: Data and trees are presented for two groups of fishes, the balitorid river loaches of southeast Asia and the Mexican tetra, Astyanax mexicanus.

The balitorids are freshwater fishes of fast moving high gradient streams, distributed throughout the Old World, but most diverse in eastern Asia. Perhaps because of their habitat and a preference to cling to rocks or hide beneath them, they have given rise to a disproportionately large number of troglobitic forms. Of the sixty plus recognized balitorids found in Thailand, five cave species are known. The data presented here were gathered to investigate the relationships of representative surface forms and to discover the placement of the cave forms among them. The trees are based on mitochondrial sequence and RAPD fingerprinting data. The four cave species in the study are Homaloptera thamicola, Schistura oedipus, Nemacheilus troglocataractus and a new cave Schistura from central Thailand. Neither Nemacheilus nor Schistura is defined unambiguously by synapomorphy and the relationships of the three species in these genera were unclear. Although the three trees differ in complexity and resolution, they clearly show that the four investigated cave forms are of independent origin.

Astyanax mexicanus is distributed throughout northern and northeastern Mexico in freshwater surface streams. In the Sierra de el Abra in NE Mexico, a number of cave populations of apparent independent origin exist. The mitochondrial tree does not show much structure, except for the clear union of the Curva and Tinaja cave populations. This is understandable, because all populations are interfertile and differentiation among them is not great. The RAPD tree shows more structure in the relationships among populations.

Mitochondrial DNA Data: The data are partial sequences from two genes, cytochrome b (fragments amplified between base 15149 and 14841{balitorids} or 14724 {Astyanax}, numbered as on the human L strand) and 12srRN(A (bases between 1091 and 1478). ("Universal primers" adapted from Kocher et al. 1989 PNAS 86:6196.) Data for the two sequences are presented separately for the balitorids, but are analysed as a combined data set for Astyanax.

RAPD Data: RAPD fingerprinting was done using standard techniques (Borowsky et al. 1995. Mol. Biol. Evo. 12:1022 and Espinasa and Borowsky, 1998 Mol. Biol. Evol. 15:408.) The data matrices for the Astyanax populations each include over 100 informative characters. The data marix for the balitorids is made up of 2757 phylogenetically informative characters. RAPD data are treated as Dollo characters in maximum parsimony analyses.

Analyses and Trees: All analyses are preliminary, pending resolution of ambiguities in sequences and the addition of new taxa. Maximum parsimony analyses were done using Paup* 4.0b1. Trees presented are bootstrapped. For Astyanax mexicanus analyses, the outgroup used was A. aeneus from Guerrero. For the balitorid trees, different outgroups were employed: for RAPDs, Lepidocephalichthys berdmorei (Cobitidae); for cytochrome b, Misgurnis anguillicaudatus (Cobitidae -- outgroup) and Crossostoma lacustre (Balitoridae -- ingroup) sequences were obtained from Genbank; for 12srRNA, Relictus solitarius and Siphateles bicolor (Cyprinidae) sequences were obtained from Genbank and used as outgroups.