Ituglanis

Abstract: A new species of Ituglanis is described from rio Iratapuru, near the rio Jari, Amapa, Brazil. The new species is distinguished from all congeners by the reduced number of post-Weberian apparatus vertebrae (36 or 37); the low number of paired ribs (2); the low number of interopercular odontodes (12–15); the number of branchiostegal rays (7 or 8); the presence of elongated fontanel in parieto-supraoccipital; the pectoral-fin rays (i,5); head length (18.9–25.0); and the presence of pores supraorbital s1, infraorbitals i1 and i3 of the laterosensory system. The new taxon has a reduced body size and fully ossified skeleton, but does not display a large number of paedomorphic traits compared to congeners. Comments about taxonomy and intrageneric comparisons are made, and paedomorphic in Ituglanis is discussed. Thoughts about conservation of the new species are presented.

Abstract: The “Our planet reviewed” expedition allowed to investigate the fish fauna from the Mitaraka Mountain Range (French Guiana). We sampled fishes at 14 sites using complementary sampling methods including rotenone, underwater observation, seine, cast nets, traps and hooks. We present the first detailed fish inventories from this region. Thirty eight species belonging to 16 families were observed, and at least one unknown species belonging to the genus Jupiaba Zanata, 1997 was collected. At two torrential sites we recorded an unusual fish assemblage made of a single Trichomycteridae species, Ituglanis nebulosus de Pinna & Keith, 2003. A few rare species were also recorded such as Pimelodella procera Mees, 1983 hereby extending its known distribution 100 km Southward. Anablepsoides gaucheri (Keith, Nandrin & Le Bail, 2006) was collected for the first time since its description in 2006. This species was collected in a stream located 15 km eastern from its type location, revealing its distribution might span over the entire Mitaraka range. Overall, the species turnover between sites was high even between sites with similar environmental conditions, suggesting that dispersal limitation is playing a significant role in fish assemblage composition. This indicates that complementary inventories in nearby areas may still provide new species and original information on the fish fauna inhabiting small streams of Southern French Guiana.

Abstract: Ituglanis nebulosus is described from the Aprouague basin in French Guiana. It differs from all other species of Ituglanis by a color pattern composed of large, round spots irregularly distributed on body and not coalesced into longitudinal stripes. It is also diagnosable from most congeners by the round caudal fin and the reduced number of vertebrae (35 or 36). The new species shares all synapomorphies so far proposed for the genus Ituglanis, as well as other characteristics supporting the placement of the genus within trichomycterids.

Abstract: The Andean and preandean regions are characterized by the presence of several endorheic drainage basins, each of which has evolved a characteristic fish fauna, some of which are poorly known or hitherto inaccessible. We describe here a new species of Trichomycterus from Aguarague National Park, Bolivia. Trichomycterus aguarague is considered to belong to a species assemblage comprised of T. alterus, T. boylei, T. ramosus, and T. belensis, a group diagnosed by three putative apomorphic conditions: (1) base of the maxillary barbel wide and engrossed like a skin flap or fold, (2) premaxillary bone smaller than maxilla, and (3) odontodes embedded in thick integument that covers interopercle. Alternatively, T. aguarague and T. alterus share an unusual number of five or fewer abdominal vertebrae, which is a synapomorphy for the group composed of Scleronema, Ituglanis, and the Stegophilinae+Tridentinae+Vandelliinae+Glanapteryginae+Sarcoglanidinae clade. The new species differs from all congeners in having the following combination of characters: caudal peduncle depth 13.5 – 16.0% SL, 15 or 16 pairs of ribs, 15 dorsal procurrent rays, 12 ventral procurrent rays, 8 pectoral fin rays; 9 anal fin rays; barbels and skin of trunk with numerous, minute thread-like papillae.