Hexanematichthys Bleeker, 1858

(Figs 1–3, 24D, 32)

Type species: Bagrus sondaicus Valenciennes, 1840 .

Diagnosis

Posterior branches of mesethmoid moderately long, delimiting between one-fourth and one-half of length of anterior cranial fontanel (8, 0> 1); posterior branch of lateral ethmoid depressed (13, 0> 1); posterior cranial fontanel absent (26, 1> 0); epiphyseal bar indistinct (28, 0> 1); temporal fossa absent (38, 0> 1); accessory tooth plates small, oval to rounded (60, 2> 1); lateral margins of orbitosphenoid progressively diverging anteriorly (63, 0> 1); autopalatine posterior portion conspicuously compressed (106, 0> 1); articulation of autopalatine with lateral ethmoid mesoposteriorly oriented (110, 0> 1); lateral and mesial portions of premaxilla with different sizes (121, 0> 1); anteroventral portion of opercle subtrapezoidal, very long (127, 1> 0); Müllerian ramus distal third markedly curved (208, 1> 2).

Ambiguous optimization: Exoccipital bony crest perpendicular to vertebral column and ventrolaterally directed (92, 1> 0); 15 or more ribs (213, 0> 1); second dorsal cleithral process posteriorly directed and parallel to posterior process (226, 1> 0).

Included species

Hexanematichthys sagor Hamilton, 1822 .

Habitat and distribution: Brackish and marine waters, South and Southeast Asia (Fig. 24).

Remarks

The total-evidence analysis supports the validity of Hexanematichthys, corroborating the result of a previous molecular study (Betancur-R. 2009) that reveals a strong morphological convergence between Hexanematichthys and Sciades (characters 26, 28, 93, 106, and 110), which had resulted in them having previously been treated as synonyms (Marceniuk et al. 2012).