Ptychochromis Steindachner, 1880

Sparks, John S. & Stiassny, Melanie L. J., 2010, A new species of Ptychochromis from northeastern Madagascar (Teleostei: Cichlidae), with an updated phylogeny and revised diagnosis for the genus, Zootaxa 2341, pp. 33-51 : 34

Ptychochromis Steindachner, 1880

Type species: Ptychochromis oligacanthus ( Bleeker, 1868)

Generic diagnosis. A ptychochromin genus diagnosed by the presence of a free second epibranchial toothplate ( Stiassny & Sparks, 2006: Fig. 7 A), exclusion of the second infraorbital bone (IO2) from the orbit by IO3 ( Stiassny & Sparks, 2006: Fig. 8 F), a prominent palatine groove ( Stiassny & Sparks, 2006: Fig. 6 F– G), ventrally displaced insertion of the palatine-palatine ligament compared to other ptychochromin genera (Stiassny & Sparks: Fig. 6 F–G), a horizontally oriented palatine bone with an elongate palatine prong and weakly elevated lateral ethmoid process ( Fig. 2 ; Stiassny & Sparks, 2006: Fig. 6 G; modified in members of the “western clade”), and anterior displacement of the supraneural bones such that the anterior element comes to overlie the dorsoposterior margin of the supraoccipital crest ( Fig. 3 A–C; lacking in members of the “western clade”).

Note that due to a typographic error in our prior diagnosis for Ptychochromis ( Stiassny & Sparks, 2006: 14) we erroneously state that IO3 is excluded from the orbital margin by IO2, however, this feature is correctly described above (i.e., IO2 excluded from orbital margin by IO3). The remainder of the text, character description, cladogram, figures, and dataset are correct with respect to the configuration, coding, and interpretation of this feature ( Stiassny & Sparks, 2006: character 11).

Figures

FIGURE 2. Left lateral view of the oral jaws and anterior region of the suspensorium of P. ernestmagnusi (AMNH 249489, paratype, 87.5 mm SL, female, C & S) illustrating the “ eastern type palatine ” (shaded in gray) morphology.

FIGURE 3. Left lateral view of the dorsoposterior margin of the neurocranium illustrating morphology of the supraneural bones (in black) and their relationship to the supraoccipital bone. A) Ptychochromis ernestmagnusi, B) P. makira, C) P. c u r v i d e n s, and D) P. oligacanthus. Arrows indicate degree of overlap of supraoccipital crest by anterior supraneural.

FIGURE 6. Relative geographic distributions of species of Ptychochromis exhibiting the “ eastern type palatine ” configuration, including the geographically proximate sister species, P. m a k i r a and P. ernestmagnusi, new species. Note: Arrow for P. grandidieri indicates that distribution for species extends southward along the eastern coast of Madagascar.

FIGURE 7. Lateral pigmentation pattern in preservation for: A) Ptychochromis makira (AMNH 237131, holotype, 151.0 mm SL, adult male), and B) P. ernestmagnusi (AMNH 249488, paratype, 99.5 mm SL, adult). Dashed lines indicate relative adult lateral barring pattern and orientation.

FIGURE 8. Strict consensus cladogram of nine optimal topologies recovered (tree length = 1018, CI = 0.67, RI = 0.61) based on the simultaneous analysis of the nucleotide dataset of Stiassny and Sparks (2006) and 24 morphological transformations. Unambiguously optimized morphological features supporting recovered nodes are designated by solid (unique feature) and open (homoplasious feature) circles. Character numbers (above braches) and states (below branches) correspond to the morphological transformations listed in Table 2 and Appendix 1. Indices in bold at nodes indicate jackknife support. Character state descriptions and statistics are listed in Appendix 1. The morphological character matrix is presented in Table 2.