Astyanax mexicanus genetic linkage map from a Texas surface fish × Pachón cavefish cross. The names of the genomic markers are indicated at the right of each linkage group. LG ids for this cross are shown at the top with LG ids corresponding to the numbering scheme of Protas et al.  made from the F2 progeny of Mexican surface fish × Pachón cavefish cross shown in parentheses. NA indicates that there is no homologous linkage group in Protas et al. . The bars denote Bayesian credible intervals with probability coverage as 0.95. New genes placed on the map in this study were the 5-hydroxytryptamine (serotonin) receptors (5ht1A, 5ht2A, 5ht2B, 5ht2C, 5ht2C_like), dopamine receptor D1 (drd1), eyes absent homolog 1 (eya1), monoamine oxidase (mao); melanin-concentrating hormone receptor 2 (mchr2), neurogenin 1 (ngn1), neuregulin 2 (nrg2); pro-melanin concentrating hormone (pmch); profilin 2 (pfn2); serotonin transporter (sert); tyrosine hydroxylase 1 and 2 (th, th2); and tryptophan hydroxylase 2 (tph2). Other genes (cryaa, hsp90a, igfbp5, mc1r, mc2r, mch1r, oca2, pax6, shhA, shroom2, tfe3) were genotyped and mapped as in previous studies [7, 22, 34].