Hypostomus isbrueckeri Reis, Weber & Malabarba, 1990

Terán, Guillermo E., Serra, Wilson, Díaz, Federico Ruiz, Alonso, Felipe, Bugeau, Baltazar, Aguilera, Gastón & Mirande, J. Marcos, 2022, On the presence of the poorly documented Hypostomus isbrueckeri Reis, Weber & Malabarba, 1990 (Siluriformes: Loricariidae) in Argentina and extension of its distribution range., Ichthyological Contributions of PecesCriollos 81, pp. 1-5 : 1-2

Hypostomus isbrueckeri Reis, Weber & Malabarba, 1990 ( fig. 1 -3)

Argentina, Corrientes: CI-FML 7798. 1 ex, 199.3 mm SL. Miriñay River , Uruguay River basin, 29°33'42.19"S 57°30'36.85"W, coll. Terán, Aguilera, Ruiz Diaz & Mirande, Sep.2019 (figs. 3, 4) . CI-FML 7799. 1 ex, 247.0 mm SL. Miriñay River , Uruguay River basin, 29°33'42.19"S 57°30'36.85"W, coll. Bugeau, Ruiz Díaz, Terán, Aguilera & Mirande, Dec.2021 .

The morphometric and meristic measurements of the analyzed specimens are presented in table 1. The collected specimens have characteristics that allow their identification as Hypostomus isbrueckeri , in particular, the presence of rounded dark spots on a pale background on the body and paired fins, smaller and closer together on the head, absent on the caudal fin and fused to form vertical stripes on the dorsal fin ( figures 1 -3). This last characteristic seems to be distinctive compared to other species of the genus. However, the vertical white band on the margin of the caudal fin, considered diagnostic for this species, was not observed.

The analyzed specimens come from the province of Corrientes (northeast of Argentina), from the middle basin of the Uruguay River ( figure 4 ). Previously known records for Argentina corresponded to the province of Misiones, associated with the upper part of the Uruguay River (Araya et al. 2012; Flores et al. 2015). The collection site in the Miriñay River (figure 5) has a rocky bottom without submerged vegetation and shallower sectors with running water.

Figures

fig. 1 (left) Preserved specimen of Hypostomus isbrueckeri from Miriñay River, Argentina, in lateral, dorsal and ventral views (CI-FML 7798, 199.3 mm SL).

fig. 4 Geographical distribution of Hypostomus isbrueckeri. fig. 5 Collection site of Hypostomus isbrueckeri at the New record at Miriñay river in the province of Miriñay river, Uruguay river basin, Corrientes, Corrientes (star) and previous records based on Argentina, Dec.2021 literature and comparative material (dots).