Fishes from Parque Estadual de Itapeva , Rio Grande do Sul state , Atlantic Forest biome , Brazil

The ichthyofauna herein presented was collected in streams, lake, and swamps from the Parque Estadual de Itapeva, Rio Mampituba basin. The protected area is located in the northernmost part of the coastal plain of Rio Grande do Sul state. Samplings resulted in 26 species, in 20 genera, 15 families, and six orders. Two species are listed as threatened and one near threatened in Rio Grande do Sul. This study represents the first fish survey in the protected area, Atlantic Forest biome.


INTRODUCTION
In Rio Grande do Sul state (RS) there are 23 state conservation units of public administration managed by Secretary of Environment and Sustainable Development (Secretaria do Ambiente e Desenvolvimento Sustentável, SEMA), totaling about 300,000 ha (3,000 km 2 ) of protected area.Many watercourses occur in all of these protected areas and few ichthyofaunistic studies have been done to determine the number of species or to evaluate conservation status of these species.According to Reis et al. (2003aReis et al. ( , 2003b) ) 325 freshwater fish species occur in Rio Grande do Sul state, but this number is likely underestimated.In the past decade dozens of new species have been described, and it is estimated that the number can exceed four hundred species (Bertaco et al. 2016).
The Parque Estadual de Itapeva (PEVA), created in December 2002 (State Decree 42.009/2002), is located in the northernmost part of the coastal plain of Rio Grande do Sul.It contains remnants of the Atlantic Forest, a biome strongly impacted by deforestation and pollution caused by increased urbanization (Menezes et al. 2007).The majority of the watercourses that are within of the limits of park, as well as in the surrounding area to the north of the conservation unit, are part of the Rio Mampituba basin.
The objective of this study is to provide an ichthyofaunistic inventory, which may eventually support future studies on fish biology and conservation of a poorly known and protected area.

Study site
The PEVA comprises mobile and fixed dunes, grasslands, marshy forest, dry forests, a lake, small streams and swamps.The protected area is a state conservation unit in the Integral Protection category, with an area of approximately 1,000 hectares located in the Atlantic Forest biome, at the Municipality of Torres, RS.The climate in the region is subtropical characterized by rainy winters and hot summers.A total of six sampling points were used in the streams, swamps and lake of the PEVA (Figures 1-2, Table 1).All these watercourses are in the Rio Mampituba basin (boundary between Rio Grande do Sul and Santa Catarina states).

Data collection
Specimens were collected between 7 to 9 December, 2005, using a dip net (40 × 80 cm frame and 1 mm net mesh size), gill nets (20 m × 1.8 m, 2-4 cm between knots), casting net (2 m × 1.5 cm between knots) and seine net (10 m × 2 m, 5 mm between knots).The nets were selected according to the environmental and hydrological conditions of the sampling sites.Gill nets were set for 12 to 14 h.The fishes were collected for the management plan of PEVA under permission of the Department of Forest and Protected Areas (Departamento de Florestas e Áreas Protegidas, DEFAP) of SEMA, permit number IBAMA 02023−000282/04−82.The specimens collected were fixed in 10% formalin, preserved in 70% alcohol and later identified using Malabarba et al. (2013), Giora and Malabarba (2016) and Lucena and Soares (2016).

Lists of species
do Museu de Ciências Naturais (MCN), Fundação Zoobotânica do Rio Grande do Sul, Porto Alegre (Table 2).In addition to the specimens collected during this inventory, species records from the fish collection Photos and brief diagnosis are provided for a group of species, including endangered, endemic, belonging to species complex, and recently described.
Voucher specimens are housed in the Coleção de Peixes  from the Departamento de Zoologia da Universidade Federal do Rio Grande do Sul (UFRGS), available at the SpeciesLink (http://www.splink.org.br), and the database of MCN fish collection were also used.The classification of fishes followed Reis et al. (2003a), except for Cichliformes sensu Wiley and Johnson (2010).The common names followed Malabarba et al. (2013).
The respective capture habitat (e.g."stream" for species collected in streams) for each species is given in Table 2.
The species, categorized as endangered, endemic, belonging to a species complex, recently described and/ or had the nomenclature changed, are briefly discussed below.

Material examined: Table 2
This species belongs to the A. bimaculatus species group (Garutti and Britski 2000) and can be distinguished from other species of this group by the absence of a conspicuous midlateral black stripe, presence of caudal peduncle spot, and absence of maxillary teeth.It was recently redescribed by Lucena and Soares (2016), and represents the only species of the group in the coastal rivers of southern Brazil.(Eigenmann, 1907): Figure 3C Hemigrammus boulengeri Eigenmann (1907): 15.Hyphessobrycon boulengeri (Eigenmann, 1907)  Material examined: Table 2 It may be distinguished from congeners by the presence of a vertically elongate and relatively rounded humeral spot, a narrow midlateral dark stripe on the flank, body with reticulated pattern formed by chroma tophores concentrated on posterior margin of scales, and a narrow stripe on anal-fin base (Carvalho 2006).Miquelarena, Menni, López & Casciotta, 1980:

Material examined: Table 2
The most distinctive characters of this species are the presence of two vertically elongate humeral spots, presence of faint black midline with some transverse bars anteriorly directed and chevron shaped along myomeres junction, and the sexual dimorphism of the color pattern (dorsal, anal and caudal fins reddish in females and yellowish in males).

Material examined: Table 2
It may be distinguished from the sympatric species Mimagoniates microlepis by the smaller number of branched anal-fin rays (usually 24-26 versus 28-31), larger number of scale rows between dorsal-and anal-fin origins (17-22 versus 14-17), and smaller number of scale rows around caudal peduncle (19-23 versus 15-18).Additionally, according to Azevedo et al. (2016), M. rheocharis and M. microlepis have the lowest absolute mean fecundity known for characids, indicating that inseminating species allocate less energy to oocyte production and reinforcing the hypothesis that insemination has an adaptive advantage, which provides a higher chance of fertilization.Category "Near Threatened" (NT) according to State Decree 51.797/ 2014.

Material examined: Table 2
It is diagnosed from its congeners by the incomplete lateral line with 8 to 9 perforated scales, and by the presence of a conspicuous black caudal-peduncle spot.

Material examined: Table 2
Microglanis cibelae is the most elongate Microglanis species from southern Brazil and exhibits almost completely black pectoral-and pelvic-fins (Malabarba and Mahler 1998).It differs from congeners in southern Brazil by having smaller head length (25.1-28.9%versus 29.6-33.5% SL in M. cottoides), smaller mouth width   (Bertaco and Cardoso 2005).

Material examined: Table 2
Rhamdia quelen belongs to one of the largest species complexes of fishes and is widely distributed in the Neotropical region.The coastal populations of Rhamdia from southern Brazil have distinct features and probably represent a new species (Malabarba et al. 2013).

Order Gymnotiformes Family Gymnotidae
Gymnotus aff.carapo Linnaeus, 1758: Figure 4D Gymnotus aff.carapo Linnaeus ( 1758  This species belongs to a species complex and is widely distributed in South America (Albert and Crampton 2003).According to these authors, G. carapo stricto sensu is from Surinam, and differs from all members of the group by having 16-27 (mean = 22) dark pigment bands obliquely oriented or band-pairs, with irregular wavy margins, often broken into spots above lateral line on anterior half of body.It is possible that the coastal populations of G. carapo from southern Brazil is a new species (Albert and Crampton 2003).Giora & Malabarba, 2016:

Material examined: Table 2
This species was recently described by Giora and Malabarba (2016) from coastal rivers of Rio Grande do Sul and Santa Catarina states.It belongs to the G. pantherinus species-group and it is distinguished from other group members by its yellow to dark brown ground color with thick and/or vermiculated spots from the anal-fin base to the lateral line.Category "Endangered" (EN) according to State Decree 51.797/ 2014.

Material examined: Table 2
According to Lucinda (2008) Phalloceros spiloura is diagnosed from congeners by having a rounded spot located on the lower half of the caudal peduncle close to the base of the lowest caudal-fin rays, a patch of dark pigmentation on the last anal-fin ray of females, and the halves of gonopodial paired appendix straight and perpendicular to ray 3. It was described from coastal drainages of Rio Grande do Sul and Santa Catarina states, rio Uruguay and rio Iguaçu, and recently its geographic distribution was extended to Laguna dos Patos system (Bonato and Ferrer 2013).

DISCUSSION
The total number of freshwater fish species in the Rio Mampituba basin is still unclear, but according to Malabarba et al. (2013) and Bertaco et al. (2016) about 70 species occur in this basin.Based on the results of this inventory, the fish diversity in the watercourses of PEVA is relatively high, comprising 37% (26 species) of the total number of freshwater species estimated for the Rio Mampituba basin.On the other hand, all species recorded in the PEVA are also found in the rio Tramandaí system (Malabarba et al. 2013).This sharing of species is congruent with the freshwater ecoregion Tramandaí-Mampituba recognized by Abell et al. (2008).
According to Vari and Malabarba (1998), Castro (1999) and Lowe-McConnell (1999), the predominance of Characiformes and Siluriformes seems to be a trend for Neotropical rivers, a condition supported in this study with a predominance of Characiformes.The low number of Siluriforms in the catches may be due to the characteristics of the area sampled, such as the absence of rocky substrate, since the bottom is constituted mainly of mud and sand, low current, and abundant aquatic vegetation.
Among the endangered species found in PEVA, Atlantirivulus riograndensis and Gymnotus refugio are in the category "Endangered" mainly due to its restricted area of distribution and the loss and degradation of their habitats.These species prefer the shallowest parts of small streams, swamps and flooded areas located usually at the border of marshy forest.The species categorized as "Near Threatened", Mimagoniates rheocharis, is usually found in lentic environment or slow flowing small streams with clear water in the Atlantic Forest, between southern Santa Catarina and northeastern Rio Grande do Sul states.The species is in this category mainly due to deforestation, water pollution and changes in headwaters, resulting in loss and degradation of habitat.According to Colombo et al. (2008), the main threats in the area of PEVA are forest drainage, habitat fragmentation, and wetland degradation.
The high congruence of the ichthyofauna of PEVA with those of the Mampituba and Tramandaí Rivers, as well as the presence of threatened species, reinforces the importance of preservation of the conservation unit in the Atlantic Forest biome.

Figure 1 .
Figure 1.Study area showing the collection sites in the Parque Estadual de Itapeva, Rio Grande do Sul state, Brazil.The red dot in the South America map indicates the conservation unit.
Azevedo and Bertaco | Fishes from Parque Estadual de Itapeva, Rio Grande do Sul, Brazil (Ří ĉan and Kullander 2008) and can be distinguished from its congeners by the presence of six anal-fin spines, four abdominal bars, well developed caudal-fin spot, and gray ground color.According to Ří ĉan and Kullander (2008) the coastal populations from southern Brazil are different from A. facetus by the color pattern and a combination of meristic characters.

Table 1 .
Azevedo and Bertaco | Fishes from Parque Estadual de Itapeva, Rio Grande do Sul, Brazil List of sampling sites and sampling methods used in the Parque Estadual de Itapeva, Torres, Rio Grande do Sul state, Brazil.

Table 2 .
List of fish species collected in the Parque Estadual de Itapeva, Torres, Rio Grande do Sul state, Brazil and their respective capture area.

Table 2
This is the only species of the genus occurring in southern Brazil and differs from congeners by having dark brown dots over the dorsal portion of the flank and dorsum in females.Females have a small dark gray spot on the dorsal portion of caudal-fin base.Category "Endangered" (EN) according to State Decree 51.797/2014.

Table 2
This species belongs to the Australoheros facetus group

Table 2
It can be distinguished from Australoheros cf.facetus, a very similar species, by the presence of three anal-fin spines versus six (Ří ĉan and Kullander 2006).