Betancurichthys, Marceniuk & Oliveira & Ferraris Jr, 2024

Marceniuk, Alexandre Pires, Oliveira, Claudio & Ferraris Jr, Carl J., 2024, A new classification of the family Ariidae (Osteichthyes: Ostariophysi: Siluriformes) based on combined analyses of morphological and molecular data, Zoological Journal of the Linnean Society 200 (2), pp. 426-476 : 454-455

Betancurichthys gen. nov.

( Figs 1–3 , 27 )

ZooBank registration: urn:lsid:zoobank.org:act:CF91C445-9AA0-4852-8291-6F9FD57C9CD2 .

Type species: Arius madagascariensis Vaillant, 1894 .

Diagnosis

Bony bridge formed by lateral ethmoid and frontal cylindrical and thin (16, 0> 1); frontal mesial laminar projection absent (23, 1> 0); posterior cranial fontanel formed by frontals and parieto-supraoccipital (25, 1> 0); otolith posterior margin rounded (74, 1> 0); dorsal crest of premaxilla beginning between lateral one-third or one-half of anterior margin (124, 0> 1); third basibranchial chalice shaped (168, 0> 1); dorsal-fin spine prolonged into filament (221, 0> 1).

Ambiguous optimization: Sesamoid bone I very long and subtriangular (145, 0> 1).

Etymology

Named after Colombian ichthyologist Ricardo Betancur-R. for his dedication to the knowledge of the taxonomy, evolution, and biogeography of marine catfishes. Gender: masculine.

Included species

Betancurichthys festinus Ng & Sparks, 2003 * sedis mutabilis Betancurichthys madagascariensis Vaillant, 1894 Betancurichthys uncinatus Ng & Sparks, 2003 * sedis mutabilis.

Habitat and distribution: Fresh and brackish waters, western Madagascar ( Fig. 24 ).

Remarks

The genus Betancurichthys was established to accommodate species endemic to Madagascar, in the western Indian Ocean, corroborating molecular results presented by Betancur-R. (2009). Its inclusion in the Ariina is supported by the BI and ML analyses. The inclusion of Betancurichthys festinus and Betancurichthys uncinatus in the genus is provisional, based on the distribution and life habits of the species restricted to freshwater in Madagascar.

Figures

Figure 1. MP analysis.Subfamilies (SF) Galeichthyinae (pink), Bagreinae (bright blue), and Ariinae (dark blue). Tribe (T) Ariini (blue), Cathopsini (orange), Genidentini tribe nov. (brown), and Sciadeini tribe nov. (light green).Subtribe (ST) Ariina (light blue) and Doiichthyina (green). Incertae sedis taxa (IS) (red). Numbers over branches correspond to the bootstrap support.

Figure 2. ML analysis. Subfamilies (SF) Galeichthyinae (pink), Bagreinae (bright blue), and Ariinae (dark blue). Tribe (T) Ariini (blue), Cathopsini (orange), Genidentini tribe nov. (brown), and Sciadeini tribe nov. (light green). Subtribe (ST) Ariina (light blue) and Doiichthyina (green). Incertae sedis taxa (IS) (red). Numbers over branches correspond to the bootstrap support.

Figure 3. BI analysis.Subfamilies (SF) Galeichthyinae (pink), Bagreinae (bright blue), and Ariinae (dark blue). Tribe (T) Ariini (blue), Cathopsini (orange), Genidentini tribe nov. (brown), and Sciadeini tribe nov. (light green).Subtribe (ST) Ariina (light blue) and Doiichthyina (green). Incertae sedis taxa (IS) (red). Numbers over branches correspond to the bootstrap support.

Figure 24. Representative skulls, in dorsal view, and distribution of the subtribe Ariina.A, Arius maculatus, AUM 44875. B, Cephalocassis melanochir, CAS 49426. C, Cryptarius truncatus, AUM 50243. D, Hexanematichthys sagor, AUM 50242. E, Kyataphisa nenga, AUM 46280. F, Osteogeneiosus militaris, AUM 44880. G, Pseudosciades sona, AUM 44861. * marine, ** brackish water, *** freshwater.

Figure 27. Betancurichthys madagascariensis, MNHN 1894-0002, western Madagascar, type species of the genus.