Acanthochromis .

— As discussed above, Acanthochromis was formerly classified with Chromis and its relatives (e.g., McCulloch, 1929; Whitley, 1929; Marshall, 1964; Allen, 1975a, 1991), prior to its reclassification in the subfamily Pomacentrinae (Cooper et al., 2009) . Acanthochromis polyacanthus, the sole member of the genus, was initially the only pomacentrid known to lack a dispersive planktonic phase, a rare occurence in marine species, and the only damselfish reported to engage in parental care of juvenile offspring (Robertson, 1973; Allen, 1975a; Thresher, 1984; Nakazono, 1993; Kavanagh, 1998, 2000). With its limited capacity for dispersal, it is no surprise that different populations display variation in their coloration, genetics, life history, morphology, and ontogeny (Planes and Doherty, 1997a, 1997b; Kavanagh, 2000; Planes et al., 2001). The extensive divergence in color patterns, where individual localities often have unique color morphs, is likely the result of a strong preference for mates with similar color patterns (Allen, 1975a, 1991; Doherty et al., 1994; Planes and Doherty, 1997a, 1997b; Kavanagh, 2000). Its sister-group relationship to Altrichthys is well supported (100% bootstrap; Fig. 1).