Arius Valenciennes, 1840

(Figs 1–2, 24A – 25)

Type species: Pimelodus arius Hamilton, 1822 .

Diagnosis

Bony bridge formed by lateral ethmoid and frontal cylindrical and thin (16, 0> 1); frontal mesial laminar projection absent (23, 1> 0); accessory tooth plates ventral to orbitosphenoid and metapterygoid (62, 0> 1); orbitosphenoid and pterosphenoid lateral expansions slight projections with sinuous lateral face (65, 0> 2); autopalatine very compressed at articulation with lateral ethmoid (108, 0> 1); dorsal crest of premaxilla beginning between lateral one-third or one-half of anterior margin (124, 0> 1); lateral margin of third pharyngobranchial well developed and acute (193, 0> 1).

Ambiguous optimization: Müllerian ramus bone blade evident only in basal third (206, 2> 1).

Included species

Arius acutirostris Day, 1877 * sedis mutabilis

Arius africanus Günther, 1867 * sedis mutabilis

Arius arenarius Müller & Troschel, 1849 * sedis mutabilis Arius arius Hamilton, 1822

Arius brunellii Zollezi, 1939 * sedis mutabilis

Arius burmanicus Day, 1870 * sedis mutabilis

Arius dispar Herre, 1926

454 • Marceniuk et al.

Arius gagora Hamilton, 1822

Arius jatius Hamilton, 1822 * sedis mutabilis

Arius jella Day, 1877 * sedis mutabilis

Arius leptonotacanthus Bleeker, 1849 sedis mutabilis

Arius macronotacanthus Bleeker, 1846 * sedis mutabilis

Arius maculatus Thunberg, 1792

Arius malabaricus Day, 1877 * sedis mutabilis

Arius manillensis Valenciennes, 1840

Arius microcephalus Bleeker, 1855 * sedis mutabilis

Arius nenga Hamilton, 1822 sedis mutabilis

Arius aff. nenga sedis mutabilis

Arius oetik Bleeker, 1846

Arius subrostratus Valenciennes, 1840 * sedis mutabilis

Arius venosus Valenciennes, 1840 * sedis mutabilis.

Habitat and distribution: Fresh and brackish waters, eastern Africa and South to Southeast Asia (Fig. 24).

Remarks

The genus Arius undoubtedly has the most complex taxonomy of the Ariidae, serving to accommodate taxa without clear affinities elsewhere (Marceniuk and Menezes2007). Recent morphological studies have recognized the monophyly of Arius with the inclusion of Betancurichthys madagascariensis (Marceniuk and Menezes 2007, Marceniuk et al. 2012), an arrangement not supported by Betancur-R. (2009), a molecular study that does not recognize the monophyly of Arius . The MP and ML analysis supports the monophyly of Arius without Betancurichthys madagascariensis .