New Species of Trichomycterus (Siluriformes: Trichomycteridae) from Wetlands of High Elevation of Argentina, with Notes on the T. alterus Species-Complex
Trichomycterus puna, new species, is described from a small tributary of the Corral Blanco in Catamarca Province, Argentina, as part of an ongoing systematic study of the genus Trichomycterus from the High Andean Plateau or Altiplano-Puna drainages of the southern Central Andes. The new species is distinguished from congeners by the following characters: the odontodes embedded in thick integument that covers interopercle, the premaxillary bone smaller than maxilla, the presence of sesamoid supraorbital with lateral process, the supraorbital sensory pore s3 present, the discontinuous supraorbital sensory canal, 2–3 premaxillary tooth rows, the uniformly dark pigmentation on the trunk, 15 precaudal vertebrae, the skin of trunk with minute thread-like papillae, 7–8 pectoral-fin rays, 9–12 dorsal procurrent caudal-fin rays, 10–11 ventral procurrent caudal-fin rays, the distally unbranched barbels, the wider interorbital distance, 16 pairs of ribs, the first dorsal-fin pterygiophore inserting on vertebra 18, and the first anal-fin pterygiophore inserting on vertebra 21. It closely resembles T. alterus, T. belensis, T. boylei, and T. ramosus from the Puna region. Trichomycterus belensis and T. catamarcensis are recorded from new localities over 3,400 m elevation.
Trichomycterus puna, holotype, FACEN 151, 74.1 mm SL, Argentina, Provincia Catamarca, Departamento Belén, El Angosto creek.
Dorsal view of head in (A) Trichomycterus puna, FACEN 172, paratype; (B) T. corduvensis, FACEN 178. Abbreviations: iop, interopercle; op, opercle; s3, supraorbital pore 3. Scale bar = 5 mm.
Trichomycterus puna, FACEN 165, paratype, 60.7 mm SL. (A) Dorsal view of upper jaw and associated structures; (B) ventral view of left hyoid arch; (C) lateral view of left interopercle. The arrow indicates the interopercle bone curved upwards. Abbreviations: a, autopalatine; ac, anterior ceratohyal; br, branchiostegal rays; l, lachrymal; le, lateral ethmoid; m, maxilla; me, mesethmoid; p, premaxilla; pc, posterior ceratohyal; s, supraorbital tendon bone; vh, ventral hypohyal.
Left lateral view of head in (A) Trichomycterus puna, FACEN 164, paratype; (B) T. corduvensis, FACEN 178. Abbreviations: iop, interopercle; op, opercle; mx, maxillary barbel. Scale bar = 5 mm.
Type locality of Trichomycterus puna, El Angosto endorheic creek, Departamento Belén, Provincia Catamarca, Argentina: (A) spring season; (B) winter season.
Northwestern Argentina showing distribution of Trichomycterus: T. puna (black star), T. alterus (green circles), sympatric T. belensis and T. catamarcensis (red circles), T. minus (light-blue circle), T. ramosus (yellow circle), T. yuska (pink circle).
Localities of Trichomycterus belensis and T. catamarcensis: (A) Laguna Blanca type locality; (B) Encrucijada new locality; (C) La Angostura new locality: spring water at 17°C (red arrow), without trout Oncorhynchus mykiss and main stream at 4°C (blue arrow), which only trout inhabit.
Contributor Notes
Associate Editor: R. E. Reis.