Table 2 - uploaded by Katia Facure
Content may be subject to copyright.
Abundance and mass of R. giarettai and environmental variables measured in plots in Dam Reservoirs (DR) (n=39) and Free Flowing Waters (FFW) (n=60 plots) along Veredas (Palm Grove Marshes) in Uberlândia (MG), Brazil
Source publication
We present data on the habitat, density, and spatial distribution of Rivulus giarettai, and discuss some biotic and abiotic variables related to its abundance in Free Flowing Waters (FFW) and Dam Reservoirs (DR)
in palm grove (Mauritia flexuosa) marshes (Veredas) in Uberlândia, Minas Gerais, southeastern Brazil. The mean density (individuals/plot)...
Similar publications
Osteological and soft anatomical features of representatives of poeciliine genera were studied to test the monophyly of the poeciliine tribes and to advance a hypothesis of relationships within the subfamily. The resultant hypothesis supports the proposal of a new classification for the subfamily Poeciliinae. Diagnoses are provided for suprageneric...
In the wild, prey species often live in the vicinity of predators, rendering the ability to assess risk on a moment-to-moment basis crucial to survival. Visual cues are important as they allow prey to assess predator species, size, proximity and behaviour. However, few studies have explicitly examined prey's ability to assess risk based on predator...
The median lethal concentration (CL50) and the anesthetic efficacy of eugenol were determined to diverse doses on the swordfish Xiphophorus helleri (Heckel, 1848). For the determination of the CL50 was used 10 individuals in triplicate in the control and in each concentration. The estimated CL50 to 96 h for eugenol was 22.12 mg.L-1. The efficacy of...
Citations
... The genus is almost completely restricted to Brazil, where it is found mostly in the Cerrado biome, in the central portion of the country (Costa, 2006, Oliveira et al., 2012. The exceptions are M. schuncki (Costa & De Luca) endemic to the floodplains of lower Amazon River, at the Amapá state in northern Brazil, Melanorivulus punctatus (Boulenger), occurring in the Chaco and the adjacent Pantanal areas in Bolivia, Brazil, Paraguay and Argentina (Costa, 1995a;Schindler & Etzel, 2008), and the clade comprising M. atlanticus and M. decoratus, occurring in savanna enclaves within the semi-arid Caatinga biome and coastal plains of Northeastern Brazil (Costa, 2010;Costa et al, 2015). ...
A new species of Melanorivulus, belonging to the Melanorivulus zygonectes species group, is described from the rio Galera, a tributary of the right bank of the upper rio Guaporé, Amazon basin, Mato Grosso state, Brazil. It is diagnosed from congeners by the following combination of characters: absence of pelvic fins; presence of a black band along the entire caudal-fin margin in males, typically more conspicuous on dorsal and ventral portions; presence of a wide oblique bars anteriorly and wide chevron-like marks posteriorly to middle of flank. This is the first record of the genus Melanorivulus for the rio Madeira basin.
... However, species which inhabit degraded and fragmented systems would seem to be most vulnerable to fire and firerelated disturbances (Dunham et al. 2003). In this study, a fire was observed in June, but it seemed to have no effect on the variables studied here, as no significant changes were observed immediately after the fire on the population structure of Melanorivulus giarettai (Costa 2008) from Bvereda^habitats (Oliveira et al. 2012). As pointed out by Minshall et al. (2001), fire may affect aquatic organisms over the long term, suggesting that this population should be monitored over a long time course to determine the real effects of fire and other significant environmental disturbances. ...
Species of Melanorivulus present behaviour and physiological traits that allow them to live in marginal aquatic habitats. In particular, Melanorivulus rossoi is a small nonannual fish only known from its type locality in the Brazilian Cerrado. In this study, we aimed to characterize the distribution and temporal variation in body size, sex ratio, density, length-weight relationship (LWR) and condition factor (CF) of M. rossoi in its natural habitat. To accomplish this, fish samples were taken monthly for a year using sieve nets every 30 min. Body size of males and females increased throughout the year until early summer. LWR was significant, and general coefficient of determination (r²) was 92%. Juveniles showed negative allometric growth, but adults showed positive allometric growth. Both sexes presented the same tendency of temporal variation in CF, with lower values in October and January and peaks in September and February. Fire occurred in June, but no difference in population parameters was observed after this event. A decrease in the abundance of Melanorivulus was related with an increase in the abundance of Erythrinidae juveniles. This might be explained by an increased predation of this species over the M. rossoi individuals, when the population was reduced to about 30% of that in the previous months. We report four new locations where this species was recorded; thus, similar to most Rivulidae members, M. rossoi has a restricted distribution area and is threatened with extinction. Therefore, our results may be useful in developing management strategies aimed at conservation of this species and its habitat in Brazil.
... The region comprising the Cerrado savannas of central Brazil has been considered among the most important biodiversity hotspots in the world (Myers et al. 2000), although many organisms endemic to this region were insufficiently sampled and poorly known until recent years . A typical component of the Cerrado fauna is the killifish genus Melanorivulus Costa, 2006, with species inhabiting the Veredas, a Cerrado ecosystem consisting of small streams running in shallow valleys, often exhibiting the buriti-palm Mauritia flexuosa along their banks (e.g., Costa 2007a; Oliveira et al. 2012). Probably as a consequence of small size, usually not surpassing 45 mm of total length, species of Melanorivulus occurring in this ecosystem were not represented in collections until recent years, with the great majority of the approximately 40 species occurring in the central Brazilian Cerrado being described only after 2005 (e.g., Costa 2012;Costa et al. 2016). ...
Three new species are described from the Neotropical region comprising the Cerrado savannas of the central Brazilian plateaus, which is among the most important biodiversity centres in the world. These species are considered closely related to Melanorivulusdapazi from the same region, with which they share the presence of a rudimentary interarcual cartilage and a dark reddish brown distal margin on the male anal fin. The group comprising Melanorivulusdapazi and the three new species is here named as the Melanorivulusdapazi species group. Melanorivulusignescenssp. n., from the upper Rio Araguaia basin, is distinguished from all other species of the Melanorivulusdapazi group by the anal-fin colour pattern in males; Melanorivulusflavipinnissp. n. and Melanorivulusregularissp. n. from the Rio Paraguai basin are distinguished from all other congeners of the Melanorivulusdapazi group by the colour pattern of the caudal fin and number of scales in the longitudinal series, respectively. All the new species are further unambiguously diagnosed by unique combinations of morphological characters, including meristic and morphometric data, and colour patterns. This study reinforces the importance of using live colour patterns to diagnose species and species groups of the genus Melanorivulus, but also indicates that osteological characters may be informative for species diagnosis. This study confirms the high diversity of species of Melanorivulus in the central Brazilian Cerrado plateaus already reported in previous studies, indicating that endemic species are often restricted to short segments of a single river drainage.
... With great occurrence of endemic taxa, biogeographical relationships of organisms inhabiting these savannas are still poorly known (e.g., silva & Bates, 2002), as well as biological inventories in past decades have neglected some habitats, making biodiversity underestimated until recent years. This is the case of the killifish genus Melanorivulus Costa, 2006, with most species only living in shallow marginal parts of small streams draining South America savannas (Costa, 1995(Costa, , 2006oliveira et al., 2012), habitats that were poorly sampled in fish collections until recently. As a consequence, only two of the about 35 valid species of Melanorivulus were first described before 1989, in spite of the huge area occupied by this genus, between the Oiapoque river basin in northern Brazil, about 4º N, and the Uruguay river basin in northern Argentina, about 27º S, and between the Paraguay river basin in eastern Bolivia, about 60º W, and the coastal plains of north-eastern Brazil, about 37º W (e.g., Costa, 1995;Bragança et al., 2012;Costa et al., 2015). ...
... Like species of the closely related genera Anablepsoides and Atlantirivulus, species of Melanorivulus typically inhabits shallow marginal areas close to streams, about 5 to 30 cm deep (Costa, 1995(Costa, , 2006. However, differently from species of those two genera that are found in dense rain forests, species of Melanorivulus inhabit savanna-like environments (Costa, 2007b(Costa, , 2011oliveira et al., 2012). Most species are endemic to the Cerrado savanna of central Brazil and the adjacent Cerrado-Amazon ecotone (Costa, 1995(Costa, , 2005(Costa, , 2012a. ...
This study comprises the first molecular phylogeny of Melanorivulus, a genus of small killifishes inhabiting shallow streams draining South American savannas, using segments of the mitochondrial genes 16S and ND2 and the intron 1 of the nuclear S7 gene, total of 2,138 bp, for 26 taxa. Monophyly of the genus is highly supported and some clades previously diagnosed on the basis of colour patterns are corroborated. A biogeographical analysis using event-based methods indicated that the most recent common ancestor of Melanorivulus occupied a region comprising the savannas of the eastern Amazon and the ecotone Amazon-Cerrado, and the present day distribution has been shaped by a series of dispersal and vicariance events through areas today including the upland Cerrado and the lowland Pantanal. The presence of a broad stripe of dense rain forest today separating the savannas of the eastern Amazon, inhabited by M. schuncki, from the savannas located south of the Amazon, from where a clade comprising all other species of the genus is endemic, is regarded as evidence of possible geographical expansion of Melanorivulus lineages through savanna areas during past cooler and drier periods, when South American grasslands and savannas expanded and rain forests were restricted to small areas.
