Ichthyofauna of the Ribeirão Frutal and tributaries , upper Rio Paraná basin , Minas Gerais , Southeastern Brazil

The Ribeirão Frutal basin is located within the upper Rio Paraná system, in the Frutal municipality, Minas Gerais State, Southeastern Brazil. Until now, there was no complete ichthyological survey published for this small basin. Therefore, here we provided a list of fish species from the Ribeirão Frutal and some of its tributaries. We found 31 species of fishes representing five orders and ten families. We identify a likely undescribed and five non-native species in the Frutal basin. Lastly, we recommend new surveys of fishes in small hydrographic basins within upper Rio Paraná system.

The Ribeirão Frutal basin is a tributary of the Rio Grande, in the upper Rio Paraná system, Minas Gerais State (Triângulo Mineiro), Brazil.This small basin (with just over 120 Km²) (Machado & Audino 2017) has been impacted by several anthropogenic disturbances (see Machado & Audino 2017;and Brito et al. 2017 and references therein).Recently, a truck leaked a substantial volume of hydrochloric acid into one of its tributaries, the Vertente Grande, killing a large number of its aquatic organisms (Azevedo- Santos & Coelho, pers. obs.).Another threat, for instance, is the advancement of the urban area of the Frutal municipality, which may compromise the water quality of the lower Ribeirão Frutal.Despite being located in a relatively well-populated region, there has been no comprehensive survey of its fish fauna until now.In order to understand the ichthyofauna from this small basin facing numerous threats due to anthropogenic development, we here provided a survey of fish species that occur in the Ribeirão Frutal and some of its tributaries.

Material and methods
Samplings were carried April, May, August, and October 2017, using handnets (mesh of 1.5 mm), a small trawl (mesh of 1.5 mm), and gill nets (10 and 20 mm between opposite nodes).Collections involved the efforts of two researchers during daytime and, when possible, in the evening.A total of 10 localities were sampled in the Ribeirão Frutal basin (Figure 1-2; Table 1).Immediately after removal from wild, individuals of several species were photographed alive in an aquarium.Vouchers were euthanized in anesthetic (i.e., benzocaine), fixed in 10% formalin, transferred to 70% alcohol and subsequently deposited in Brazilian collections: LBP (Laboratório de Biologia de Peixes, Botucatu, Botucatu, SP, Brazil); NUP (Coleção Ictiológica do Núcleo de Pesquisas em Limnologia, Ictiologia e Aquicultura, Universidade Estadual de Maringá, Maringá, PR, Brazil); and UNT (Coleção de Peixes do Laboratório de Ictiologia Sistemática da Universidade Federal do Tocantins, Porto Nacional, TO, Brazil).Identifications were carried out using published literature and, when possible, with the help of a specialist in each group (see Acknowledgements section).All collections for this study were performed with permission of IBAMA (SISBIO -Number 58612-1).

Results
Samples resulted in 765 individuals distributed in five orders, ten families, and 31 fish species (Table 2).Among families, Characidae was the most represented, followed by Cichlidae, and Loricariidae (Figure 3).Site four (S4) presented the highest species-richness, with 16 species (Table 3).At site nine (S9), a small tributary entering the Ribeirão Frutal near its confluence with the Rio Grande, we recorded one likely undescribed species (i.e., Satanoperca sp.; Figure 4j).Finally, we found five fish species believed to be non-native to the Ribeirão Frutal basin: Cichla cf.piquiti Kullander & Ferreira 2006

Discussion
Most species found in our survey (about 87.1 %) were recorded by Langeani et al. (2007) for the upper Rio Paraná basin.However, these authors do not provide the distribution of species within the basin (see Langeani et al. 2007).Therefore, we contribute to the knowledge of the distribution of species into the Ribeirão Frutal basin, in the upper Rio Paraná system.
Recently, Santos et al. (2017) provided a list of species from two regions of the lower rio Preto, Rio Grande basin, in the upper Paraná system; relatively near the Ribeirão Frutal basin.These authors found representatives of the order Characiformes, Gymnotiformes, Cyprinodontiformes, Perciformes (=Cichliformes herein), Siluriformes, and Synbranchiformes (see Santos et al. 2017 for more details).In this work, we did not find any representatives of Gymnotiformes.As species of this order occur in the Rio Grande basin (Santos et al. 2017; see also Castro et al. 2004), it is possible that species of this order also occur at the present study location, but were merely not sampled.Langeani et al. (2007) showed that Characidae and Loricariidae, in general, are the two most species-rich families of the upper Rio Paraná basin.In addition, several ichthyofaunal surveys (e.g., Pavanelli et al. 2007, Smith et al. 2007, Oliveira et al. 2009, Fagundes et al. 2015, Hoffmann et al. 2015, Cardoso et al. 2016, Frota et al. 2016, Santos et al. 2017) show this pattern in tributaries of the basin.However, in our work Cichlidae was the second most represented family (Fig. 3); probably due to the presence of two non-native species of this family (i.e., Cichla cf.piquiti and Oreochromis niloticus).
Satanoperca sp. (Fig. 4j) is probably the undescribed species previously mentioned by Ota (2013).According to Ota (2013), this species occurs in the Tocantins/Araguaia and upper Rio Paraná basins, but there is no certainty as to whether or not it is native to the upper Paraná basin.On the other hand, Astyanax sp. is very similar to  A. paranae Eigenmann, 1914.In addition, the species collected seems to have two morphotypes in the body shape.Only with further analysis, preferably including osteological and molecular data, can we certain of its specific identification.We found a total of five non-native species in Ribeirão Frutal basin: Oreochromis niloticus, native to the Afrotropical region (Welcomme 1988), Poecilia reticulata, described based on material from "Caracas" (Peters 1859, p. 412), in Venezuela, Metynnis lippincottianus and C. cf.piquiti, both native to the Amazon basin (Jégu 2003, Kullander & Ferreira 2006), and Knodus moenkhausii, which is not native to the upper Rio Paraná basin according to Langeani et al. (2007).Hyphessobrycon eques was found only in two tributaries of the Ribeirão Frutal basin (see Tab. 3).Castro et al. (2004) were not certain whether this species was native to the Rio Grande.With no evidence to suggest recent introduction of this species to the Ribeirão Frutal, we will tentatively consider it to be native.All of the five aforementioned non-native species seem to be fully-established and reproducing at the collecting sites in Ribeirão Frutal basin.
Numerous small basins of the upper Rio Paraná system have been impacted by anthropogenic activities (e.g., Santos et al. 2017, this work).Therefore, modern and comprehensive ichthyological surveys are needed to effectively document the fish fauna of these small tributary basins.Obviously, together with these surveys, measures to avoid or minimize negative impacts to these environments should be adopted.For the Ribeirão Frutal basin, in particular, we recommended three first actions: (i) management of the non-native fish species mentioned here and initiatives to avoid new introductions (e.g., Azevedo-Santos et al. 2015); (ii) avoid urban sprawl over the basin; and (iii) remove the dams (i.e., small reservoirs) in the headwater streams of the basin.
Rhamdia quelen X X X Satanoperca sp.X

Figure 1 .
Figure 1.Map showing the Ribeirão Frutal basin with the sites sampled in the basin, upper Rio Paraná system, Brazil.Shaded area represents the urban perimeter of the Frutal municipality.

Figure 2 .
Figure 2. Photos showing stretches of each sampling site (S1 to S10) from the Ribeirão Frutal basin, upper Rio Paraná system, Brazil.

Table 1 .
Sampled localities in the Ribeirão Frutal basin, upper Rio Paraná system, Brazil.Lower portion of left tributary of the Ribeirão Frutal; known as "Córrego do Marianinho".Its headwater is the target of the expansion of the urban perimeter.A tributary of left side of the Ribeirão Frutal; known as "Vertente Grande".This tributary has much of its course within the urban perimeter (with sections channeled by cement).There are evidences that the tributary receives domestic effluents.
A tributary of left side of the Ribeirão Frutal; known as "Córrego do Jaó".It presents sections with riparian vegetation.A stretch upstream is dammed and forms a small reservoir.Near to the tributary there is an expansion of the urban perimeter.S8 19°55'52.0"S,48°56'05.1"WThe first tributary of the Ribeirão Frutal, left side.Unknown name.S9 20°06'11.6"S,48°57'32.2"WLeft side tributary of the Ribeirão Frutal.Unknown name.Probably one of the most heavily impacted tributaries with dams (forming small reservoirs) in different stretches.We observed the cultivation of oranges near to the affluent.S10 20°04'25.3"S,48°57'02.4"WLeft side tributary of the Ribeirão Frutal; known as "Córrego do Sal".