Ribeira De Iguape Research Articles

Species boundaries of the whiptail catfish Rineloricaria (Siluriformes: Loricariidae) from the Paraíba do Sul River drainage, southeastern Brazil, with species redescriptions and description of a new species.

Species of the catfish genus Rineloricaria are common in the Paraíba do Sul River basin, in southeastern Brazil; here we present a revision of the taxonomic diversity and geographic distribution of the species of the genus inhabiting the basin, based on novel morphologic and molecular data. Five species delimitation methods based on cytochrome C oxidase subunit 1 nucleotide sequences yielded comparable molecular operational taxonomic units. The automatic barcode gap discovery, assemble species by automatic partitioning, barcode index number, and Bayesian implementation of the Poisson tree process methods supported the recognition of five evolutionary lineages. These taxonomic units were assigned to the previously described Rineloricaria nigricauda, Rineloricaria steindachneri, Rineloricaria zawadzkii, and Rineloricaria nudipectoris, and an additional undescribed species. R. zawadzkii was further divided into two intraspecific geographically structured lineages using the generalized mixed Yule coalescent delimitation method. A maximum likelihood phylogenetic analysis revealed that the five lineages from the Paraíba do Sul have closer relationships to different species from southern and southeastern Brazil (Ribeira de Iguape, Lagoa dos Patos, Uruguay, Paraguay, and Parana river basins) than to each other. Based on the analysis of lectotypes, recently collected material, and specimens from ichthyological collections, the poorly described R. nigricauda and R. steindachneri are redescribed following current descriptive standards. The undescribed species from the middle and upper Paraíba do Sul River basin is formally described. The description of a new species, along with the description of species boundaries in R. nigricauda and R. steindachneri, contributes to the knowledge of the ichthyofauna of the Paraíba do Sul River basin and adjacent coastal drainages of southeastern Brazil. An identification key for the species of Rineloricaria occurring in the Paraíba do Sul River basin is provided.

A new record of ground sloth in the Ribeira de Iguape valley, southeastern Brazil

In the early 1980s, an assemblage of extinct and extant vertebrates was collected from the Abismo Ponta de Flecha, a vertical cave in southern São Paulo, Brazil, for archaeological, geological, and paleontological analyses. While materials identified as ground sloths have been referenced in earlier publications, they have never been thoroughly described. In this study, we provide the first detailed description of a large, previously unidentified taxon found in Brazil, interpreted herein as belonging to the family Nothrotheriidae. Although direct dating of the specimen was not possible, other dated occurrences from the Ribeira de Iguape Valley suggest that it may have inhabited the region during the Late Pleistocene, coinciding with the local presence of a dense forest cover.

DNA barcode shows discordant cases among morphological and molecular species identification in Isbrueckerichthys (Siluriformes: Loricariidae)

Abstract Isbrueckerichthys is a genus of armored catfish (Siluriformes: Loricariidae) with five species in the lowlands from the Ribeira de Iguape basin and in the uplands of the Tibagi River basin. Despite the validation of the morphological species, molecular data to investigate gene flow and species delimitation have not been completed for all species. For this purpose, we compared sequences of COI region associated with barcoding molecular identification, aiming for a species delimitation analysis and generating population data of I. alipionis, I. epakmos, I. duseni, I. cf. duseni, I. saxicola, and I. calvus. The K2P genetic distance, molecular species delimitation analysis, and well-sustained branches in the phylogenetic tree validate I. alipionis, I. epakmos, and I. duseni, and suggest I. cf. duseni as a valid molecular operational taxonomic unit. However, no differences were detected between I. saxicola and I. calvus. The discordance between molecular and morphological species may be due to the recent dispersal of some Isbrueckerichthys representatives at the border between the Ribeira de Iguape and Tibagi basins. The isolation features of the mountainous region of Ribeira de Iguape basin and headwaters captures to uplands are presented to explain the dispersion and the cases of incipient speciation in Isbrueckerichthys lineages.

Rainfall variability in the São Paulo area of ​​the Ribeira de Iguape river basin (Brazil) and the influence of ENOS, based on the Box- Plot technique

Foi realizada uma análise das precipitações pluviais mensais durante anos influenciados pelos fenômenos El Niño-Oscilação Sul (ENOS) no Vale do Ribeira de Iguape, localizado no sudeste do estado de São Paulo. Dados de 1970 a 2017 de 18 postos pluviométricos distribuídos pelo alto, médio e baixo curso do rio Ribeira de Iguape foram analisados utilizando a metodologia Box-Plot para a identificação de anos-padrão mensais. Observou-se um excedente hídrico nas precipitações durante anos de influência de ENOS, enquanto em anos de influência dos fenômenos La Niña (LA) verificou-se uma maior variabilidade nas precipitações pluviais. Em muitos anos de ENOS, os excedentes ocorreram principalmente na primavera (outubro, novembro e dezembro) e no final do verão (janeiro, fevereiro e março). Na fase de LA, as secas foram mais evidentes na primavera (setembro e outubro) e nos meses de fevereiro e março. Conclui-se que o fenômeno na região apresenta variabilidade mensal e não segue um padrão constante e espacialmente regular. Portanto, é necessário analisar e compreender outros fenômenos atmosféricos, como as frentes frias, o Modo Anular Sul (MAS), o Dipolo do Atlântico Sul, e o EN Canônico/Modoki, entre outros, que podem influenciar as dinâmicas das precipitações pluviais na região.

Hidden diversity and evolutionary diversification in Phalloceros harpagos Lucinda (Cyprinodontiformes: Poeciliidae)

AbstractThe distribution of Phalloceros species is generally allopatric and restricted; however, Phalloceros harpagos has a wide distribution and exhibits morphological variation among populations from different Brazilian river basins. Different species delimitation tests using cytochrome C oxidase subunit I gene sequences indicated that P. harpagos is a species complex that comprises between 7 and 9 phylogroups. The separation of the Paraná and Paraíba do Sul River basins most likely caused the diversification of these phylogroups in the Miocene period. The majority of phylogroups have a narrow distribution; however, one phylogroup has a broad distribution, being found primarily in the Paraná, Ribeira de Iguape, and Iguaçu River basins. This distribution can be attributed to possible headwater capture events caused by the reactivation of faults and erosion in the quaternary. Estimates about the times of divergence based on molecular data could be used to infer the biogeographic processes related to the diversification of South American freshwater fish.

Estimating river discharge from rainfall satellite data through simple statistical models

Quantitative knowledge of river discharge measurements is essential for understanding coastal and estuarine dynamics and salinity variations. However, direct measurements are scarce for a large portion of rivers in Brazil. In this study, five simple models based on remote sensing and local rainfall datasets (MERGE) for the Ribeira de Iguape catchment are used to estimate the Valo Grande Channel (VGC) discharge on the southeastern coast of Brazil. These models use linear, quadratic, exponential, and two different multiple linear regression methods. The predicted VGC discharge time series resulting from each model is compared with the estimated time series based on in situ data from the Water and Electric Energy Department (DAEE in Portuguese). The estimated time series presented reasonable results, with skills varying from 0.84 to 0.92 and Nash–Sutcliffe efficiency (NSE) indices varying from 0.54 to 0.75, with the highest values corresponding to the multiple linear regression models. This methodology allowed us to reproduce longer time series at a daily frequency, as well as monthly averages between 2000 and 2020.

Spintherobolus papilliferus in the rio Ribeira de Iguape basin: implications for the biogeography and conservation of an endangered species (Ostariophysi: Characiformes)

Abstract Spintherobolus papilliferus is an endangered characid endemic of the Atlantic Rainforest, known from sparse locations in the upper rio Tietê basin around the metropolitan area of São Paulo city, and from an affluent of rio Itapanhaú, a coastal stream in Bertioga, São Paulo State. In 2020, S. papilliferus was sampled from the rio Ribeira de Iguape basin in Juquitiba, São Paulo State, representing a new distributional record. We compared 17 morphometric and six meristic characters from all specimens with data from the rios Tietê and Itapanhaú. An overlap in the morphological data from the three populations was detected, except for five measure whose values are lower in rio Ribeira de Iguape. MANOVA and LDA revealed that this population differs significantly from the other two, showing shallower body and caudal peduncle, among other features. These morphological differences may be due to environmental selective pressures since rio Ribeira de Iguape drainage is marked by fast waters which can influence the shape of fish bodies over time. DNA-barcoding of all Spintherobolus species corroborate that the rio Ribeira de Iguape population belongs to S. papilliferus. We also present a hypothesis for the disjunct distribution of S. papilliferus involving headwater capture and discuss the implications for the conservation of this endangered species.

Cingulata of the Abismo Ponta de Flecha Cave (Pleistocene-Holocene), Ribeira de Iguape Valley, southeastern Brazil

The Ribeira de Iguape Valley, located in southeastern Brazil, is an important karstic region, presenting a large number of caves containing fossil and subfossil vertebrate materials. The Abismo Ponta de Flecha Cave is a complex vertical cave divided into galleries where a large amount of osteological material was collected. The cave acted as a natural trap for several taxa and possibly as a disposal site for ancient human communities. Osteoderms and appendicular bones assigned to two genera of Cingulata were identified in the faunal assemblage. The most abundant bone material belongs to the family Chlamyphoridae, genus Cabassous, represented by the living species C. tatouay and by remains of a larger, but little-known species, cf. C. antiquus. The other identified genus belongs to the family Dasypodidae: Dasypus sp. Evidence of human activity was characterized in only one C. tatouay bone, while the other specimens were considered as being of natural origin. Keywords: Quaternary, Chlamyphoridae, Dasypus, Cabassous, taxonomy.

What factors affect the fishing resources of the middle stretch of the River Ribeira de Iguape (SP)?

What factors affect the fishing resources of the middle stretch of the River Ribeira de Iguape (SP)?

Quaternary ungulates of the Abismo Ponta de Flecha Cave, Ribeira of Iguape Valley, Southeast Brazil: Zooarchaeological and Paleoenvironmental aspects

The Ribeira de Iguape Valley, located in the south of the state of São Paulo, presents a complex system of caves developed from Precambrian carbonate rocks. The presence of such karstic system favored the preservation of numerous fossilized remains of Quaternary mammals. The Abismo Ponta de Flecha Cave, located in the municipality of Iporanga, is a vertical cave divided into several lateral galleries with abundant vertebrate specimens. Among the most common are the ungulates, a clade of mammals characterized mainly by the presence of hooves, represented by the Holoarctic ungulates families Cervidae, Tayassuidae, Tapiridae, and the South American native ungulate Toxodontidae. The most common family in the deposit is Tayassuidae, with several individuals assigned to the species Tayassu pecari, Dicotyles tajacu, as well as an indeterminate large Tayassuidae. The Cervidae remains found in the cave have two species assigned to the genus Mazama; M. americana and M. gouazoubira. A specimen of the Tapiridae family, Tapirus sp., was also found. Only one species attributed to the extinct family Toxodontidae, Toxodon platensis, was recorded. Many specimens of Tayassuidae and Cervidae were subadults, and one individual of Tayassu pecari was very young. The origin of the specimens might be the result of the transport of individual bone parts, the death of accidently trapped animals as well as the disposal of such remains by human groups that inhabited the region in the past.

Composition and distribution of rotifers in Rio de Janeiro State: a first assessment through freshwater ecoregions

ABSTRACT The species richness is an essential component of biodiversity metrics and an ecological indicator for setting conservation actions. Phylum Rotifera consists of a specious group of conspicuous and minute animals, mainly in freshwater environments. In the Neotropical region, the knowledge of the biodiversity of rotifers is incomplete, with outdated and geographically restricted information. In this regard, we present a comprehensive inventory of rotifers from freshwater ecoregions in Rio de Janeiro. From the literature review and active surveillance, we detected 238 spp.; among these, 39 were previously unknown to the State. We also preliminarily examine the potential use of Rotifera for ecoregions delimitation. The extrapolated number of species shows an increasing richness for the Paraiba do Sul and Fluminense ecoregions, which were also significantly different regarding species composition. Registers from the Ribeira de Iguape and Northern Mata Atlantica ecoregions are still lacking in the State. We believe that future survey efforts will undoubtedly reveal additional records and taxa improving our understanding of biogeographical patterns such as dispersal and biological invasions. Ultimately, support future conservation policies and the potentialities of this group for ecoregion delimitations.

Semiautomatic inventory and geomorphological characterization of mass movements using high-resolution images and open-source software in the Ribeira de Iguape Valley, Brazil

In Brazil, as in many countries, inventories of mass movements usually exist for specific events and on a watershed scale and are predominantly produced from visual interpretation of aerial or orbital images, and those produced using automatic and semiautomatic methods are incipient in the national context. One of these events, the Ribeira de Iguape River Valley (Southeast Brazil), was severely affected by mass movements between January 13 and 14, 2014. The objective of this article was to produce a semiautomatic inventory and perform a brief geomorphological evaluation. of the mass movements triggered. A TanDEM-X digital elevation model (DEM) (12 m) was used to extract the watersheds (area: 109.7 km2) most affected by mass movements and multispectral images of the RapidEye satellites, captured before (01-10-2014) and after (01-30-2014) the event. From the multispectral images, the pre-event and post-event NDVI and the difference between the NDVI on these two dates were computed. Using the angle map, contribution area and topographic wetness index (TWI), the map of affected areas was refined into two classes: deposits of debris flows and other hydrodynamic mass movements (slope angle <6°; TWI <14; and contribution area >50,000 m2) and scars from shallow landslides (slope angle >6°; TWI <14; contribution area <50,000 m2). Approximately 5% of the total area was affected by mass movements, with 1.44 km2 of area corresponding to deposits of flows and other hydrodynamic mass movements and 4.04 km2 of area corresponding to scars from landslides. In total, 2089 landslide scars were mapped. The most affected slopes had angles between 20° and 40°, a TWI less than 9.0 and a concave curvature in profile and in planform, and approximately 90% of the scars occurred in areas covered by dense vegetation (NDVI >0.80 on 01-10-2014). The results may contribute to the expansion of the application of automatic and semiautomatic methods for the detection of mass movement scars in Brazil in a systematic manner using open source software.

Comment on Souza and Perez Filho (2019) “Late Holocene coastal dynamics, climate pulses and low terraces in the coast of the state of São Paulo, southeast Brazil”

Souza and Perez Filho (2019) inferred two transgressive events in the Late Holocene record of lower Ribeira de Iguape River and Ilha Comprida barrier, Southeastern Brazil, based on luminescence ages and paleoenvironmental interpretation of four columnar sections. In the present paper, we discuss inconsistencies on the methods applied and sample design adopted by those authors, which lead to an incorrect model of coastline evolution for the region over the time period covered by the dates obtained. The dataset presented by Souza and Perez Filho (2019) allows the reinterpretation of the deposits studied as regressive and fits into previous models of regional coastal evolution.

Taxonomic and functional diversity patterns of stream fish assemblages from Brazilian Atlantic Rain Forest

Disentangling the hierarchical structure of river systems and multi-scale environmental effects is essential for understanding freshwater fish community structure and function. We sampled 70 stream stretches to investigate how the taxonomic and functional composition and diversity of fish assemblages responded to the environment considering a hierarchical organisation of streams in three Brazilian watersheds (Upper Sorocaba, Upper Paranapanema and Upper Ribeira de Iguape). Functional diversity indicated that stream fish community function was independent of the watershed. The most critical environmental variable was substrate gradient. In streams with a consolidated substrate, equitability and functional dispersion were low due to invertivores occurring in this type of substrate. Our results highlight the importance of local environmental filters for shaping streams fish assemblages across different basins. This shaping was more evident when functional descriptors of assemblages were analysed, thereby reinforcing the importance of an approach based on traits as a tool to elucidate local community assembly processes at broader spatial scales.

Deep Genomic Divergence and Phenotypic Admixture of the Treefrog Dendropsophus elegans (Hylidae: Amphibia) Coincide With Riverine Boundaries at the Brazilian Atlantic Forest

The Atlantic Forest (AF) domain is one of the Earth’s biodiversity hotspots, known for its high levels of species diversity and endemism. Factors related to palaeoenvironmental dynamics, such as the establishment of vegetational refugia and river basins, have different impacts on biological communities and biodiversity patterns in this domain. Here, we sample genome-wide RADseq data from a widespread treefrog (Dendropsophus elegans), inhabiting natural and human-impacted ecosystems at the Brazilian AF to test the impact of riverine boundaries and climatic refugia on population structure and diversification. We estimate divergence times and migration rate across identified genetic breaks related to the rivers Doce, Paraíba do Sul, Ribeira de Iguape, and Paraguaçu, known to represent barriers to gene flow for other AF endemic species, and test the role of climatic refugia. Finally, we investigate the impact of spatio-temporal population history on morphological variation in this species. We recovered a phylogeographic history supporting three distinct clades separated into two geographically structured populations, corresponding to the north and south of AF. In addition, we identified an admixture zone between north and south populations in the latitude close to the Doce River. Our findings support a pattern of isolation-by-distance and the existence of a secondary contact zone between populations, which might have been promoted by gene flow during population expansion. Further, we found support for models considering migration parameters for all the tested rivers with different population divergence times. Based on the species history and the AF palaeoenvironmental dynamics, we corroborate the role of forest refugia impacting population structure for this species through recent range expansion after the Last Glacial Maximum (LGM). The Doce and Paraíba do Sul Rivers coincide with the main genetic breaks, suggesting they might also have played a role in the diversification processes. Finally, despite finding subtle correlations for phenotypic data among different populations, variation is not strongly detectable and does not seem associated with speciation-level processes that could warrant taxonomic changes. Such results can be explained by phenotypic plasticity of the evaluated traits and by recent divergence times, where there has been insufficient time and weak selective pressures to accumulate enough phenotypic differences.

Scanning Electron Microscopy (SEM) in the surficial cover analysis of the low fluvial-marine terraces in the southern coast of São Paulo state, Brazil

The Ribeira de Iguape estuarine system in Southeastern Brazil has resulted from the complex interactions betweenallogenic (climate, tectonics, and human interventions) and autogenic geomorphological processes. Early studies have shownthat the relationship between sedimentary balances, fluvial discharge, and Holocene climate pulses resulted in the coastlinedisplacement and low fluvial-marine terraces morphogenesis, which are composed of the marine and fluvial sedimentaryunits. In this perspective, this study aimed to investigate whether the microtextural and morphological records on the quartzgrains associated with the different allostratigraphic units (marine and fluvial) correspond to the paleoenvironmentsidentified in previous studies. In this study we have used a combination of analyses (grain-size, microtextural, and absolutedating) applied to the surficial cover sampled from two fluvial-marine terraces located on the right and left banks of theIguape river channel. The results show correspondences between paleoenvironments and microtextures found on the quartzgrains, confirming the statements addressed in previous studies that indicated the coastline was positioned about 9 kminland around 3.5-2.7 ka.

Semiautomatic Inventory and Geomorphological Characterization of Mass Movements Using High-Resolution Images and Open Source Software in the Ribeira De Iguape Valley, Brazil

Semiautomatic Inventory and Geomorphological Characterization of Mass Movements Using High-Resolution Images and Open Source Software in the Ribeira De Iguape Valley, Brazil

Protected areas and compositional diversity of fish from Serranias Costeiras of the Ribeira de Iguape River basin, Southeast Brazil

Abstract The Serranias Costeiras of the Ribeira de Iguape River basin comprise landscapes with steep slopes, where many streams are contained in protected areas. We evaluated the importance of these protected areas for stream fish diversity. We sampled the ichthyofauna during the dry season of 2010, 2018 and 2019 in 36 stream stretches. We used beta diversity measures and estimated species richness and dark diversity in streams from two types of protected areas (full protection, FP and sustainable use, SU) and outside (Out). The altitude-width and velocity gradient of the streams explained the species turnover. The PA type promoted the richness difference, with FP streams having less species richness than SU and outside. Streams from FP presented lower species richness and dark diversity. These results indicate that the few species in FPs are well protected. The FP streams contain a relevant proportion of the regional species pool and, therefore, are essential for conserving fish stream diversity in the study region. On the other hand, streams from SU or Out have higher species richness, but their fish fauna is more vulnerable. Due to longitudinal stream connectivity, we highlight the importance of rethinking the limits of protected areas.

Earthworm species in Musa spp. plantations in Brazil and worldwide.

Bananas and plantains are major commodity/food crops that represent an important habitat for earthworms, although so far, no review is available on earthworm communities associated with banana/plantain crops worldwide. The Vale do Ribeira region is among the largest banana producing areas in Brazil, but little is known of the earthworms living there. Hence, the present study assessed earthworm populations and species in three banana plantations and adjacent Atlantic forest fragments along the Ribeira de Iguape River using standard (hand sorting) methodologies. Furthermore, we review earthworm populations reported in banana/plantain plantations worldwide. Only two species (Pontoscolex corethrurus, Amynthas gracilis) belonging to two families (Rhinodrilidae, Megascolecidae) were found in the Ribeira River valley, occurring concurrently. Abundance was low (< 13 indiv. m-2) compared with other banana plantations worldwide, that frequently surpassed 100 indiv. m-2. More than 70 studies reported earthworms from >200 banana plantations in 28 countries, and mean species richness was 2.7 per site, ranging from 1 to 10 species. Exotics predominated in most sites and P. corethrurus was the most prevalent species encountered. Overall, more than 104 species from 10 families were reported, with around 61 native and 43 exotic widespread species, mainly of the Megascolecidae, Lumbricidae and Acanthodrilidae families. Richness was highest in India (27 spp.) and the Canary Islands (25 spp.), but native species dominated only in a few countries and sites, while exotics were prevalent especially in island countries and Brazil. Lower-input practices appear to be important for earthworm communities and banana plantations can have large earthworm populations in some cases, which may be contributing to soil processes and plant production, topics that deserve further attention. However, many important banana-producing countries have not yet been evaluated, so further work is warranted, both in terms of applied ecology and biodiversity.

A new species of Macrothrix (Crustacea, Branchiopoda, Macrothricidae) from the Neotropics with description of the marthae-group.

Publications of the last three decades demonstrated the existence of some compact species groups within the Macrothrix Baird genus (Cladocera: Macrothricidae). Many species were included in hirsuticornis-group, laticornis-group, rosea-triserialis-group and paulensis-group, but not in Macrothrix marthae group. It has a peculiar set of morphological traits not observed in any other species, so far. Studying material from Ribeira de Iguape River, Brazil, we found some individuals that resemble M. marthae, which represent a new species described herein. Macrothrix lourdesae sp. nov shares with M. marthae similar morphology of Inner Distal Lobe setae and the same modifications on the fourth and fifth limbs. The main difference between them is related to the number of setae in the exopodite of the third limb. Observing the high number of morphological traits shared, it is possible to indicate that M. lourdesae sp. nov and M. marthae form a separate species group within the genus.