New records of freshwater fish for Uruguay

191 Check List | Volume 6 | Issue 2 | 2010 Scarce knowledge about number and distribution of species limits not only our understanding of the ecological and evolutive processes but also affect our capacity to use this information in conservation management plans (Maitland 1995). As occurs in the whole Neotropical region, the knowledge about the freshwater ichthyofauna of Uruguay is clearly incomplete. Freshwater systems of Uruguay include part of the middle and lower sections of the Uruguay river, small coastal drainages flowing into the Río de la Plata and Atlantic Ocean, and the southwestern Merin Lagoon basin (Patos-Merin system). Nión et al. (2002) presented a list of the fish species of the country, however that list did not provide distributional data, or specimens voucher locations, and was based only in bibliographic sources, some of them outdated. As part of a general taxonomic revision of freshwater fish species of Uruguay, we reviewed the fish collection of Facultad de Ciencias, Montevideo, Uruguay. In this note we report the first record of eight freshwater fish species for Uruguay, extending their current distribution. Specimens reported belong to Facultad de Ciencias (Institutional code: ZVC-P), Montevideo, Uruguay. Details of analyzed lots are given in Apendix 1. Characiformes were identified according to Malabarba and Weitzman (2003) (Cyanocharax) and Casciotta et al. (2005) (Leporinus); Siluriformes acording to Sacramento-Soares and Martins-Pinheiro (2008) and Koch and Reis (1996) (Tatia), Malabarba and Mahler (1998) (Microglanis), and Reis (1997) (Lepthoplosternum); Cichlidae according to Lucena and Kullander (1992) (Crenicichla), and Casciotta et al. (2005) (Apistogramma).

Scarce knowledge about number and distribution of species limits not only our understanding of the ecological and evolutive processes but also affect our capacity to use this information in conservation management plans (Maitland 1995).As occurs in the whole Neotropical region, the knowledge about the freshwater ichthyofauna of Uruguay is clearly incomplete.Freshwater systems of Uruguay include part of the middle and lower sections of the Uruguay river, small coastal drainages flowing into the Río de la Plata and Atlantic Ocean, and the southwestern Merin Lagoon basin (Patos-Merin system).Nión et al. (2002) presented a list of the fish species of the country, however that list did not provide distributional data, or specimens voucher locations, and was based only in bibliographic sources, some of them outdated.As part of a general taxonomic revision of freshwater fish species of Uruguay, we reviewed the fish collection of Facultad de Ciencias, Montevideo, Uruguay.In this note we report the first record of eight freshwater fish species for Uruguay, extending their current distribution.
Specimens reported belong to Facultad de Ciencias (Institutional code: ZVC-P), Montevideo, Uruguay.Details of analyzed lots are given in Apendix 1. Characiformes were identified according to Malabarba and Weitzman (2003)

Order Siluriformes
Callichthyidae: Lepthoplosternum pectorale (Figure 1C) Specimens recorded present external characteristics of Callichthyinae and the coracoids exposed ventrally, caudal fin convex, one dorsal spine and 7 branched rays that permits the recognition of Lepthoplosternum.The number of dorsal and ventral lateral plates, the body width allows us to classify these specimens as L. pectorale.We found this species in the Uruguay River basin at two different localities, a modified wetland in the northern region of Uruguay and in Esteros de Farrapos a wetland system (National Protected Area) of the lower section of the river (Figure 2B) Pseudopimelodidae: Microglanis aff.eurystoma (Figure 1D) Specimens present all external characteristics of the genus (Malabarba and Mahler 1998) and the diagnostic characteristics of the species: extremely large mouth gape and squarish head shape.This species was collected in the middle Cuareim River, the northern tributary of the Uruguay River in Uruguay (Figure 2C).

Auchenipteridae:
Tatia boemia (Figure 1E) The specimen presents all the externally recognized characteristics of the genus proposed by Sacramento-Soares and Martins-Pinheiro (2008): anal fin base reduced in males and caudal peduncle laterally compressed and deep with middorsal keel.Furthermore it presented the diagnostic characteristic of the species consisting in a unique body pigmentation pattern.The specimen was recently collected in the middle Cuareim River (Uruguay River basin) (Figure 2B).

Order Percifomes
Cichlidae: Apistogramma borellii (Figure 1F) Specimens recorded present the first branchial arch with dermal lobe, characteristic of Geophaginae plus scales of the anterior section of lateral line separated from dorsal fin base by 1 scale and body side blue characteristic of A. borellii.Specimens were collected in Laguna Redonda, Franquia, a floodplain lagoons adjacent to Uruguay River close to the Cuareim River outlet (Figure 2A).1G) Specimens recorded present the diagnostic characters: absent or reduced suborbital stripe, a row of blotches along the middle of the side, dark dots only present on the caudal peduncle, upper and lower lip folds interrupted anteriorly, lips not lobed, and lower jaw distinctly prognathous.Specimens with these characteristics are present in many localities along Uruguay River main course and tributaries, including several localities in the largest effluent of the lower Uruguay River, the Negro River (Figure 2D).1H) Specimens recorded present the diagnostic characters: absent or reduced suborbital stripe, a row of blotches along the middle of the side, dark dots only present on the caudal peduncle, upper and lower lip folds interrupted anteriorly, lips not lobed, and lower jaw isognathous.The new distribution records of this species are similar to C. missioneira (Figure 2A).

C. minuano (Figure
The present work adds eight new species for the Uruguayan ichthyofauna.The present note is the first record of L. lacustris, A. borellii, and L. pectorale for the Uruguay River.These species were previously restricted to the middle Paraná River (Casciotta et al. 2005;Reis 1997).
Cyanocharax alegretensis, M. aff.euristoma were previously recorded for Ibicuy River (middle Uruguay River basin) (Malabarba and Weiztman 2003;Malabarba and Mahler 1998), so we extend their southern limit to Cuareim River.Tatia boemia was considered endemic of the upper Uruguay River (Kock and Reis 1996;Sacramento-Soares and Martins-Pinheiro 2008), the present record extends its distribution approximately 700 km to the south.Similar cases correspond to C. missioneria and C. minuano, species cited previously from tributaries of middle and upper Uruguay River (Lucena and Kullander 1992); these new records extend their distribution to Negro River, the largest tributary of the lower Uruguay River.We report the presence of Leporinus lacustris, Lepthoplosternum pectorale, and Apistogramma borellii registered from the middle Paraná River (Casciotta et al. 2005) in the middle and lower Uruguay River, this evidence that ictiogeographic zonation of the Uruguay River and its relationship with the Paraná River basin are not resolved yet.
Characidae:Cyanocharax alegretensis (Figure1B) The specimens recorded present the external appearance of Cyanocharax species and some of the distinguishing characters proposed for the genus byMalabarba and Weitzman (2003): two unbranched and eight branched dorsal-fin rays, one branched and six branched pelvic-fin rays, anterior mouth with Check List | Volume 6 | Issue 2 | 2010 Zarucki et al. | New records of freshwater fish for Uruguay unspecialized teeth, and incompletely toothed maxilla; they can be recognized as C. alegretensis by the interrupted lateral line, anal fin origin along the vertical through dorsal fin-origin, branched anal fin rays 25, anal fin with a basal sheath of scales, consisting of 1 row with 17 small scales covering the bases of unramified and first 12 ramified anal-fin rays.Specimens were recently collected in Laguna Redonda (Franquia) a floodplain lagoon of the Uruguay River close to the Cuareim River outlet (Figure 2A).