Ilha Grande National Park Research Articles

Aspectos reprodutivos das fêmeas de Leporinus lacustris Campos, 1945 (Characiformes, Anostomidae) em uma planície de inundação Neotropical

Abstract: Aim This study evaluates the reproduction and fecundity of Leporinus lacustris in upper Paraná River floodplain environments with the objectives to (i) recognize the germ cells of folliculogenesis and oogenesis; (ii) characterize reproductive phases; (iii) investigate oocyte diameter and evaluate if this species has group synchronous or asynchronous oocyte development and if spawning is total or batch; (iv) estimate batch fecundity; (v) establish the relationship between fecundity/ovary weight, standard length, and total weight; (vi) verify the reproductive areas of this species in the upper Paraná River floodplain. Methods Sampling was carried out using gillnets in rivers, and open and closed lagoons, in March, June, September, and December 2013, 2014, 2015, 2016, 2018, and 2019 and March and September 2017. A total of 442 females were sampled and 111 subsampled, each of which had an ovary removed and fixed in Bouin solution. A subsample of 20 ovaries in the spawning capable phase were fixed in a 4% buffered formaldehyde solution to estimate the diameter of the oocytes and fecundity. The ovaries were dehydrated, embedded in historesin, cut, stained, and evaluated as regards folliculogenesis, oogenesis, development phases, and reproduction areas. Results The germ cells recorded were differentiated oogonia, primary and secondary growth oocytes, fully-grown and mature oocytes, and post-ovulatory follicles that permitted the recognition of the reproductive phases. Oocyte diameter information revealed that the species has group synchronous oocyte development, determinate fecundity and batch spawning, and eliminates an average of 38,490 oocytes. Conclusions The fact that Leporinus lacustris is reproductively successful in the Baía River and in the Fechada, Guaraná, Patos, Garças, Ventura and Ressaco do Pau Véio lagoons strengthens the importance of the areas of environmental protection of the islands and lowlands of the Paraná River, Ilha Grande National Park and Ivinheima River State Park.

Environmental perception of artisanal fishermen in the region of Ilha Grande National Park, PR/MS, after the formation of the Itaipu reservoir: traditional knowledge and human-nature interaction

The flooding of the Sete Quedas fall for the formation of the Itaipu hydroelectric power plant, on the Paraná River, had impacts on fishing. The objective of this study was to analyze the environmental perception of fishermen in the region of Ilha Grande National Park, the environmental changes that occurred after the formation of the Itaipu reservoir and their relationship with fishing in the region. Data collection was carried out through interviews, with a semi-structured script approved by the Ethics Committee of Western Paraná State University. This script consisted of 26 questions aimed at identifying the socioeconomic characteristics of the activity and the changes that occurred from 1980 to 2020. Qualitative variables were analyzed. The results showed that fishermen have knowledge and perception of the environmental changes that have occurred in the last 40 years, and of the consequences of these changes in the fishing and housing spaces where they are inserted. Moreover, they demonstrated knowledge about changes in the river bed, in the course and on the banks of the Paraná River, about silting up and the decrease and/or extinction of fish species, in line with what has been found in the scientific literature. Thus, for these artisanal fishermen, the flooding caused social, cultural and economic losses. It is necessary for public authorities to act, supported by scientific information, guiding environmental education actions and measures to mitigate the environmental impacts generated and to support the fishermen.

Semideciduous seasonal forest opiliofauna (Arachnida, Opiliones), State of Paraná, Brazil

Harvestmen are arachnids that play an important role in organic matter breakdown. However, there are many ecosystems in Brazil, including Conservation Units, which lack information about these organisms or are sub-sampled. Even in areas of Atlantic forest, a biome that hosts the greatest diversity and endemic rates of these arthropods in the world. In this perspective, the purpose of this study was to survey the harvestmen fauna in areas of Semideciduous Seasonal Forest in the Ilha Grande National Park, Paraná, southern Brazil, from February to November 2019, totaling 15 days and 60 hours, on six islands in the Paraná River. A total of 170 specimens was collected, distributed in five genera, comprising two species and three morphotypes. The low species richness may reflect the isolation of populations imposed by the island effect, however the study expanded the geographic distribution of Parapachyloides uncinatus and Discocyrtus invalidus, for which until then there was no record of occurrence in the Paraná State.

A survey of Calliphoridae and Mesembrinellidae (Diptera) in semideciduous seasonal forest, Paraná, Brazil

Calliphoridae and Mesembrinellidae include Diptera species that are good indicators of changes in forest environments. The present work aimed to inventory the Calliphoridae and Mesembrinellidae in Ilha Grande National Park and correlate the abundance of these organisms with environmental variables. Adult dipterans were collected during two expeditions in 2019 using two sampling methods, a Malaise trap and baited traps, distributed on two islands in the park. During the study, 1,007 individuals of 12 species of Calliphoridae and four species of Mesembrinellidae were collected. Family Calliphoridae was more abundant (97.12%). The abundance of native species showed a strong negative correlation with the abundance of the genus Chrysomya. Rodrigues Island (Island I) had higher diversity levels and no species of Chrysomya were recorded in this area, which may indicate a greater degree of environmental preservation. The results indicate that human action in natural environments can negatively impact species diversity, as found in Ilha Grande National Park that, historically, was partially occupied and is still in the process of regeneration.

Social wasps fauna (Vespidae) of semideciduous seasonal forest in southern Brazil

Social wasps are insects that perform numerous environmental services, with emphasis on pollination and predation of agricultural pests. However, despite the increase in efforts to know the social wasps geographical distribution and richness, there are still many areas and ecosystems with few studies of this nature, such as the Paraná State, Southern Brazil. To collaborate with these efforts, this work aimed to carry out an inventory of social wasps in semideciduous forest in the Ilha Grande National Park, an integral conservation unit in the Paraná State. The Sampling took place from February to November 2019, totalizing 15 days and 60 hours, being carried out on six islands of the Paraná River, using the active search for species and colonies records. Fourteen species were registered, distributed in six genera. The study revealed a low species richness, which may be related to the area's usage history, as well as to other factors. This highlights the need for greater sampling efforts in other areas of this conservation unit.

Integrated management of fire in Ilha Grande National Park, Brazil

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First records of Freshwater Bivalves of Ilha Grande National Park, Paraná, Brazil

The Ilha Grande National Park, Paraná, Brazil, is located in the Upper Paraná River and has characteristics typical of a floodplains. This protected area includes lagoons connected and disconnected to the Paraná River, although the latter also connect during periods of high water level, thus composing a heterogeneous group of lacustrine environments. The enormous potential the flora and fauna diversities are still little known to the region, as can be seen through benthic invertebrates, inclunding bivalves mollusks. The granulometric composition of these floodplain lagoons was formed mainly by mud and very fine sand. Furthermore, organic matter composition was predominantly of fine particulate. The other abiotic factors differed from lagoons located within the island of the park to those located in the left margin of Paraná River. The results demonstrated the importance of abiotic factors such as the physical composition of granulometric texture, organic matter and macrophyte banks, to the establishment of bivalves in these floodplain lagoons. We recorded bivalves of Pisidium (native), Diplodon (native), and Corbicula (invasive). The highest values of Diplodon sp. density were observed at São João/C lake, for Pisidium sterkianum (Pilsbry, 1897) at São João/M lake, and to Jatobá/C lagoon with high density of invasive species Corbicula fluminea (Müller, 1774). This study to obtain conduct the first records of freshwater bivalves in floodplains lagoon in the Ilha Grande National Park, and provides contributions to better understanding the ecology of these mollusks. The recording of native species in the region of Upper Paraná River floodplain after a lomg period without new records, demonstrated the importance of protecting the lagoons of the Ilha Grande National Park as they can be a possible refuge to some species of native freshwater bivalves.

Spatial distribution of aquatic Oligochaeta in Ilha Grande National Park, Brazil

Ilha Grande National Park is an important conservation unit localized in the Southern part of the upper Parana river floodplain (Brazil) that includes diverse aquatic environments. Oligochaeta (Annelida) is a large group of invertebrates, with several small specimens inhabiting almost every possible niche at most freshwater ecosystem. The goal of the present study was to examine the spatial variation of Oligochaeta community in five floodplain lakes from the Ilha Grande National Park and relate the distribution with abiotic variables. Samples were taken at five sampling stations using a modified Petersen grab. Thirteen species of Oligochaeta belonging to two families Naididae and Tubificidae were recorded. Different patterns of richness and abiotic factors were identified among the lakes located in the island and at the margin of Parana river. The different patterns of granulometric texture affected directly the distribution of the Oligochaeta assemblage of theses environments. The results of this study permit to infer that the Oligochaeta assemblage, in preserved areas, present a higher richness in relation to long term studies with more frequent samplings. We concluded that Ilha Grande National Park contributes for the preservation of benthic invertebrates.

Spatial distribution of the assemblage of Chironomidae larvae (Diptera) in five floodplain lakes from Ilha Grande National Park (Paraná - Mato Grosso do Sul State, Brazil)

Chironomidae larvae (Diptera) are one of the most important families among aquatic insects due to the higher abundance and species richness, considered an important tool for ecological studies. This study evaluated the richness of Chironomidae assemblage and related the distribution with physical and chemical variables in five lakes of the Parana river, in the Ilha Grande National Park. There were two samplings, one in the central region and another in the marginal area of the floodplain lakes. In each region were collected six samples, five for biological analysis and one for granulometric analysis. The granulometric composition and organic matter content were the principal variables influencing the density and richness of Chironomidae. The scores of the abiotic data distinguished the marginal lakes (Sao Joao, Jacare and Xambre) from the island lakes (Saraiva and Jatoba). The same segregation was observed in the distribution of Chironomidae morphotypes, and environments with higher values of organic matter, presented the lowest density and taxa richness. Thus, in this study the environmental variables directly interfered in the distribution, abundance and richness of Chironomidae of the floodplain lakes from Ilha Grande National Park, contributing to the knowledge of the diversity of this group in this area.

Relative abundance and reproductive tactics of a Loricariidae species at Saraiva Lagoon, Ilha Grande National Park, MS-PR, Brazil

This study aimed to evaluate population abundance patterns and the main events in the reproductive cycle of Loricariichthys platymetopon at Saraiva Lagoon, Ilha Grande National Park, MS-PR, Brazil. Monthly samplings were conducted from October 2004 to September 2005 in three sections of the lagoon: entrance, middle and end, which resulted in the capture of 175 individuals. Spatial and temporal variation in abundance was obtained through CPUE (number of captured individuals/1000 m² of gillnets in 12 hours). The reproductive tactics considered were: duration, time and location of spawning, oocyte diameter and fecundity. The highest relative abundance was recorded in February, in the middle section of the lagoon, and the reproductive period lasted from September to February. The prevalence of females with spent ovaries and at rest in the following months indicated that reproductive activity ceased during autumn and winter. We observed that reproduction was high at the end section of the lagoon. The recorded mean oocyte diameter was 1.67 (SD ± 0.76) mm, mean absolute fecundity was 962.1 (SD ± 382.48) oocytes, and relative fecundity was 7.60 (SD ± 2.25) oocytes/g and 5.13 (SD ± 0.75) oocytes/cm. These tactics, probably are related to the settlement of L. platymetopom in Saraiva Lagoon, as well as in the different biotopes of the Upper Paraná River floodplain.

Larvae occurrences of Rhamdia quelen (Quoy & Gaimard, 1824) (Siluriformes: Heptapteridae) in an area under dam influence in the upper Paraná River region, Brazil

Rhamdia quelen (Jundiá) is a catfish species of great interest to fish producers and researchers due to several favorable characteristics for inclusion in the Brazilian list of commercially raised fish. It has a wide geographical distribution, with occurrences reported from Central Argentina to South Mexico. Studies on the biological aspects of this species have been limited to captive adult fishes that were researched for farming purposes. Research related to ichthyoplankton has provided valuable information on spawning periods and sites and other aspects of breeding for numerous species of fish. This information is crucial for implementing management and protection strategies for these species. The studied floodplain is located in a lotic remnant between the Reservoirs of Itaipu and Engenheiro Sérgio Motta. This area is located inside a protected area (Ilha Grande National Park) in the last portion of dam-free land along the Paraná River in the Brazilian territory; however, it is still threatened by the negative effects of the dams. We conducted monthly nocturnal collections during four periods from October to March, 2003 to 2007, in 22 locations along the main channel, secondary lakes and main tributaries of the Paraná River. After collection, the individuals were classified according to the degree of development and the notochord flexion and caudal fin support elements. Data were analyzed using principal component analysis (PCA), ANOVA and Pearson correlation to relate abiotic and larval density data. The increase of capture abundances in the four studied stages suggests that R. quelen is finding conditions that are favorable to its reproduction. The increase in captures can generate questions regarding R. quelen reproductive activity, for instance, whether the species is adapting or is influenced by environmental changes created by the Paraná River dams.

Levantamento populacional do cervo-do-pantanal Blastocerus dichotomus (Mammalia, Cervidae) no Parque Nacional de Ilha Grande e entorno: implicações para a conservação

Nós conduzimos um levantamento populacional aéreo do cervo-do-pantanal, Blastocerus dichotomus (Illiger, 1815), no Parque Nacional de Ilha Grande e seu entorno, entre os estados do Paraná e Mato Grosso do Sul, Brasil, na estação seca. Utilizamos a técnica da contagem dupla, e a população foi estimada em 1.079 ± 207 cervos em uma área amostral de 1.081 km², corresponde a uma densidade de 0,998 ± 0,192 ind/km². A população mostrou-se mais concentrada no interior do parque, ocupando também várzeas alteradas fora dos limites do parque. Estes resultados devem subsidiar medidas de manejo e conservação da população no parque nacional e seu entorno, devido à enorme pressão antrópica sobre a população de cervos na região.

Spatial Patterns in Fish Assemblages of Ilha Grande National Park, Brazil

The aim of this study was to characterize spatial trends in composition and structure of the fish assemblages in Ilha Grande National Park, located on the Upper Parana River. Fish were caught bimonthly between October 2001 and August 2002 with gillnets of different mesh sizes at 10 sampling sites. Over the course of the study, 9,858 fish were collected, representing 74 species; 63 species were recorded in tributaries, 59 in the main channel of the Parana River, 48 in connected lagoons, and 38 in disconnected lagoons. Species richness, diversity, and evenness did not differ significantly, but composition and structure of the fish assemblages were significantly different among biotopes. There was no relationship between limnological variables and composition and structure of the fish assemblages in the biotopes studied. Species abundance (measured in number and biomass) was higher in lagoons compared with the other biotopes. The observed spatial variation in fish assemblages may be related to the dams situated upstream and downstream of Ilha Grande National Park. The spatial patterns in composition and structure of fish assemblages described here should be taken into account in the formulation of strategies for the management and conservation of Ilha Grande National Park.

FAUNA HELMÍNTICA DE PECES DE ALTA PLANICIE DEL RÍO PARANÁ, BRASIL

The Paraná River is formed by junction of the Grande and Paranaíba Rivers and is the principal river of the La Plata basin. From source to mouth in the La Plata River estuary, the Paraná River flows for approximately 4,695 km (Petri & Fúlfaro, 1985) and drains most of South-Central South America. There are several dams in the main channel and tributaries of the Paraná River, but a floodplain still remains with a complex of tributaries, side channels, lakes, and marginal dikes (Stevaux, 1994; Souza Filho, 2009). This floodplain extends to the States of Paraná and Mato Grosso do Sul, encompassing areas of the Ilha Grande National Park, the Ivinheima State Park and the Environmental Protection Area (APA) of the islands and floodplain of the Paraná River

Spatial and temporal distribution patterns of ichthyoplankton in a region affected by water regulation by dams

The aim of this work was to study the occurrence of ichthyoplankton in a region affected by water regulation by dams. The study area was located in the region of Ilha Grande National Park, upper Paraná River floodplain. Specifically, we examined the temporal and spatial distribution of Ichthyoplankton, identified spawning areas and established the relationships between the abundances of fish eggs and larvae and some limnological and hydrological variables. Samples were taken monthly between October and March from 2001 to 2005 at 24 sampling sites. For analytical purposes, the sampling sites were grouped into upper, middle and lower areas. The upper area of the National Park had the highest egg density and should be considered the primary spawning area. The middle area should be considered a drift area, and the lower area likely functions as a growth and feeding habitat. Statistical analyses showed that the spawning was influenced by water temperature, pH, fluviometric level and rainfall, and that larval density was influenced by pH, conductivity, dissolved oxygen and rainfall. The results also revealed that the tributaries apparently are used as migratory routes by fish, and and this shows the need to protect these sites.

Fish larvae assemblages in two floodplain lakes with different degrees of connection to the Paraná River, Brazil

The objective of this study was to assess the abundance, attributes of assemblages, and spatial and temporal distributions of fish larvae and their relationships with some abiotic variables in two floodplain lakes with different degrees of connection to the Paraná River in Ilha Grande National Park, PR, Brazil. Four sampling sites were chosen, two in each floodplain lake. Night samples were taken with plankton nets during three spawning seasons (monthly, from October to March) from 2001 to 2005. The highest diversity and abundance were recorded at Saraiva Lake, with 25 taxa being identified. In Xambrê Lake, only sedentary species were captured, and the most abundant species were Plagioscion squamosissimus and Hypophthalmus edentatus. The greatest abundance of larvae was found in the second spawning season. In the Saraiva Lake, the most abundant species were Moenkhausia aff. intermedia, Hyphessobrycon sp., and Bryconamericus stramineus, but larvae of known migratory species were also documented. In this lake, the greatest abundance of larvae was found in the third spawning. Larvae abundance was influenced by water temperature and conductivity. The high diversity and abundance recorded in Saraiva Lake may be a result of its connectivity with the Paraná River, and the low diversity and abundance observed at Xambrê Lake are likely due to its isolation from the river. This work shows the importance of these lagoons for fish development, for both sedentary and migratory species. Both lagoons may be considered to have extreme ecological importance and they are also extremely susceptible to impacts, so any careless disturbance may cause irreversible damage.

Sympatry between Alouatta caraya and Alouatta clamitans and the rediscovery of free-ranging potential hybrids in Southern Brazil

Records of sympatry between Alouatta caraya and A. clamitans are rare despite their extensive range overlap. An example of their current sympatry and the rediscovery of free-ranging potential hybrids of A. caraya and A. clamitans in the forests of the Upper Paraná River, Southern Brazil, are reported in this paper. Eight groups were observed in the study area: five monospecific groups of A. caraya, two of A. clamitans, and a group containing two adult males and two adult females of A. caraya and a sub-adult male and two adult females identified as Alouatta sp. The color of the last three individuals was a mosaic between the two species; this is consistent with previously described variations in museum specimens collected in the Paraná River in the 1940s that had been identified as potential hybrids. The results from this study emphasize the need for scientific studies in the region of the Ilha Grande National Park, one of the few regions in the Paraná River that currently harbors both howler species.

Fire effects on reptiles and mammals in Ilha Grande National Park (PR/MS), Brazil

Fire effects on reptiles and mammals in Ilha Grande National Park (PR/MS), Brazil