Stellantini Armbruster & Lujan, 2024

Armbruster, Jonathan W. & Lujan, Nathan K., 2024, New tribe-level classification of Hypostominae (Loricariidae) based on optimization of morphological states on DNA-based relationships, with descriptions of three new tribes and two new genera, Neotropical Ichthyology (e 240108) 22 (4) : -

Tribe Stellantini Armbruster & Lujan , new tribe urn:lsid:zoobank.org:act:1D1E1710-3653-4CFA-A6BB-1975401D6ADF

( Fig. 1; Tabs. 1 and S3)

Type-genus. Stellantia , new genus

Included genera.

Colossimystax , new genus

Stellantia , new genus

Phylogenetic diagnosis. Hyomandibula contacting prootic (0>1), posteromedial invagination of ceratobranchial 5 (11: 0>1), straight, spoon-shaped anterior process on metapterygoid (58: 0>1, shared with Pseudancistrini ), forward extent of anterior process of compound pterotic long, halfway through orbit or greater (112: 0>1), and straight anterolateral processes of pelvic basipterygium (167: 1>2). In addition, Stellantini uniquely possesses plates along ventral series on the caudal peduncle that are strongly bent to form a keel with the keel accentuated by having the dorsal lamina of the plates strongly concave.

Comparative diagnosis. Morphometric data reported in Tab. 1. The two species of Stellantini are dramatically different from one another, but the tribe can be identified from other Hypostominae by having a strong keel on the ventral plate series on the caudal peduncle made by the ventral lamina of each plate being strongly convex and the dorsal lamina of each plate being strongly concave (vs. maximally having a slight keel made predominantly of odontodes and the dorsal lamina of each ventral plate being flat to very slightly concave).

Geographical distribution. Both species of Stellantini are found in main channels of the upper Orinoco and Negro river basins, including the Casiquiare River, in Venezuela, Colombia, and possibly also northernmost Brazil, though no Brazilian specimens have been observed or reported ( Fig. 5).