Weight-length relationship and condition factor of Mugil cephalus (Linnaeus 1758, Mugilidea) in the special wildlife reserve of Gueumbeul (RSFG) in Senegal

The weight-length relationship and the condition factors are fundamental parameters with several uses in biology, fish ecology and fisheries management. Thus, in the Special Wildlife Reserve of Gueumbeul (SWRG) in Senegal, the weight-length relationship and condition factor were established for Mugil cephalus (Linnaeus 1758). A total of 311 individuals (97 females and 214 males) of M. cephalus were collected by the artisanal fishery using cast nets. The total length and weight ranged from 11.1 to 25 cm and 15.9 to 145.26 g, respectively. The results showed that in the SWRG, both in females (b = 2.60) and males (b = 2.899), M. cephalus had negative allometric growth. The analysis of variance showed no significant difference (p > 0.05) in the coefficients of determination between females (R = 0.96) and males (R = 0.84). Condition factors (K) were 3.07 and 1.23 for males and females respectively for M. cephalus in the reserve.

PAISAGENS FLUVIAIS E PEIXES DE RIACHO: UMA INTRODUÇÃO AOS DADOS, UNIDADES ESPACIAIS DE ANÁLISE E CLASSIFICAÇÃO

Research on riverscapes and stream fish ecology has undergone a wide progress since the 1990s. Several conditions have been pointed out as essential in this progress, including the following four: (a) availability of geo-technology and spatial data, (b) setting the regional context of study areas (biomes, large river basins, ecoregions); (c) defining hierarchical spatial units of analysis (watersheds, segments, reaches) and their attributes (e.g., area, slope, order, perennial/intermittent), and (d) classification of spatial units according to their attributes. Here we present an introduction to these topics, using examples from studies in Brazilian streams, where research progress on riverscapes and stream fish has occurred only more recently. We identify a few challenges in the Brazilian context, including the standardization and consolidation of regional and national spatial databases that support riverscape analyses, training fish ecologists in Geographic Information Systems (GIS) and spatial data, expanding the use of classification systems in different spatial coverages and resolutions, research on structural, spatial and temporal attributes of spatial units in riverscape analyses

ECOLOGIA DE PEIXES EM RIACHOS URBANOS

The development of agriculture allowed humans to congregate in settlements which developed into the modern urban societies. This urbanization process caused profound habitat changes, giving rise to urban ecosystems where the structure, functioning and the dynamics of the ecosystem are determined by human activities. Despite the increasing rates of urbanization worldwide,the ecology of urban ecosystems is poorly known. In this chapter, we focus on urban stream ecosystems to expose the current advances in urban fish ecology. We explore topics concerning urban fish biodiversity,ecological interactions and adaptation to urban systems. We also explore different approaches and methodologies for the study of urban fish. Our goal is to introduce the theoretical background and analytical tools to study urban fishes with the intent of facilitating future research

Fish Ecology of the Alto Madre de Dios River Basin (Peru): Notes on Electrofishing Surveys, Elevation, Palm Swamp and Headwater Fishes

Our study analyzes the distribution of fish communities related to the environmental variables of the Alto Madre de Dios River, an Andean-Amazon watershed of southern Peru, between 300 and 2811 m a.s.l. within the Manu Biosphere Reserve. We provide new ecological and diversity data on fishes for these poorly studied rivers and new data for palm swamp habitats. With electric fishing techniques, we collected a total of 1934 fish specimens belonging to 78 species, 42 genera and 15 families. To assess main patterns of diversity we combined SIMPER and ANOSIM with canonical correspondence analysis to obtain an overview of the community structure of fish and their distribution related to aquatic habitats. Our results show an important shift on fish diversity at 700 m a.s.l. separating headwater and middle-lowland communities. Electrofishing was a hindrance due to the depth, flow and low conductivity of the rivers, but also allowed us to capture fish not observed with other techniques. We also compared the use of elevation with slope as an alternative variable for statistical analysis. Our results show that slope offers a solid and equivalent explanation for fish distribution variability, avoids redundance, and instead of giving geographical data offers ecologically solid information.

Riverine Fish of Murshidabad: A Study on River Ganga

Murshidabad is a district of West Bengal, India and situated on the eastern bank of river Hooghly, a distributary of river Ganga. Although, many studies on fish ecology and fish systematics have been conducted largely to improve fisheries but fish diversity and their distribution pattern from conservation point of view have never been adequately addressed in the Ganga River. In this present study priority was given to prepare a consolidated list of fish fauna that have been found in the part of river Ganga which flows through the District Murshidabad. 74 species belonging to 9 orders and 24 families are found in the river Ganga of Murshidabad district. Family Cyprinidae representing highest number of species viz. 21. The order Cypriniformes is represented by 26 species followed by order Siluriformes containing 20 species.

Applications and limitations of DNA barcoding in Environmental Biology

Species identification is often difficult, especially for early life-history stages, poorly known species within diverse taxa, and microbes. Molecular genetics has contributed the technique of DNA barcoding, offering a low-tech, potentially high-impact tool for identification of species. After briefly describing a range of applications, this review focus on its use for identification of larval fishes. Molecular identification of larval fishes would increase knowledge of larval fish ecology, providing insights into reproductive ecology and population dynamics, and contribute to identification and protection of critical habitat. Other applications of environmental interest include identification of species from fecal starting material and forensic investigation. Limiting application of DNA barcoding is the environmental community's unfamiliarity withthe technique and limited development of DNA sequence archives for some taxa.