Length-weight relationships of two endemic fish species in the Júcar River Basin, Iberian Peninsula

2014 ◽  
Vol 31 (1) ◽  
pp. 246-247 ◽  
Author(s):  
J. D. Alcaraz-Hernández ◽  
F. Martínez-Capel ◽  
E. J. Olaya-Marín
Keyword(s):  
Iberian Peninsula ◽  
River Basin ◽  
Fish Species ◽  
Endemic Fish

scholarly journals Length-weight Relations of 14 Endemic Fish Species from the Upper Yangtze River Basin, China

2013 ◽  
Vol 43 (2) ◽  
pp. 163-165 ◽  
Author(s):  
Jinming Wu ◽  
Lei Li ◽  
Hao Du ◽  
Hui Zhang ◽  
Chengyou Wang ◽  
...  
Keyword(s):  
River Basin ◽  
Fish Species ◽  
Yangtze River ◽  
Yangtze River Basin ◽  
Upper Yangtze River ◽  
Endemic Fish ◽  
The Upper Yangtze River

scholarly journals Population structure and reproductive biology of Astyanax gymnodontus (Characiformes: Characidae), a poorly known endemic fish of the Iguaçu River basin, Brazil

2016 ◽  
Vol 64 (1) ◽  
pp. 69 ◽  
Author(s):  
Matheus Tenorio Baumgartner ◽  
Pedro Rogério Leandro da Silva ◽  
Gilmar Baumgartner
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
River Basin ◽  
Reproductive Biology ◽  
Body Length ◽  
Fish Species ◽  
Energy Allocation ◽  
Influence Area ◽  
Endemic Fish ◽  
Iguaçu River

Success in fish breeding depends on reproduction intensity, periodicity and the place where it occurs. Information about fish species reproduction is important to assist managers, and to determine conservation and management strategies. The fish assemblage of the Iguaçu River basin is already known for its high endemism, and despite this privilege, the large number of dams built along it, threat this particular biodiversity. Astyanax gymnodontus is an endemic fish species and studies on its population structure and reproductive biology are important, since they represent the first step for further community studies. Our objective was to evaluate some aspects of the population structure and reproductive biology of A. gymnodontus in the influence area of Salto Santiago dam, Iguaçu River, Paraná State, Brazil. Sampling was made monthly from July 2003 to June 2005, and bimonthly from July 2005 to March 2013, at five sites in the influence area of Salto Santiago dam. Fishes were collected using 10 m length gillnets with meshes ranging from 2.5 to 6.0 cm between non-adjacent knots and trammel nets with inner meshes of 6.0 cm between non-adjacent knots. Nets were arranged on surface, bottom and margins of each site, exposed for 24 h. Additional drags on littoral areas were performed from January to March and October to December from 2009 to 2011, with 50.0 m nets, 0.5 cm mesh size, for juveniles capture. We captured and analyzed 21 932 individuals, being 9 249 females and 12 683 males, representing 42.2 % and 57.8 %, respectively. The average body length was 8.8 cm for females and 8.3 cm for males. The average weight was 18.8 g for females and 16.0 g for males. Sex ratio calculated for the entire period was 1.8 males/female. Males were more abundant than females in 73.2 % of samples and significant differences were observed in 35.3 % of samples. The estimated length at first maturity (SL50) was 6.4 cm for females and 6.2 cm for males. We suggest that sexual differences in body length and weight, and sex ratio occurred as a result of sexual differences in energy allocation. Females spend more energy on body growth, which means more eggs production and higher fecundity. As an integrated response, males spend more energy on sperm production, in competition with other males, leading to a smaller body size. Differences in estimated SL50 might be an indicator of this sexual difference in energy allocation. The reproduction period was from September to February, with greater intensity at the beginning of this period, and the sites of highest reproductive intensity were those immediate downstream from dams, and therefore with more riverine characteristics.

scholarly journals Modelling critical factors affecting the distribution of the vulnerable endemic Eastern Iberian barbel (Luciobarbus guiraonis) in Mediterranean rivers

2015 ◽  
Vol 17 (1) ◽  
pp. 264 ◽  
Author(s):  
E. J. OLAYA-MARIN ◽  
F. MARTÍNEZ-CAPEL ◽  
R. GARCÍA-BARTUAL ◽  
P. VEZZA
Keyword(s):  
River Basin ◽  
Fish Species ◽  
Model Parameters ◽  
Physical Habitat ◽  
Mediterranean Rivers ◽  
Exotic Fish ◽  
Gradient Descent Algorithm ◽  
River Basin District ◽  
Endemic Fish ◽  
Exotic Fish Species

Luciobarbus guiraonis (Eastern Iberian barbel) is an endemic fish species restricted to Spain, mainly distributed in the Júcar River Basin District. Its study is important because there is little knowledge about its biology and ecology. To improve the knowledge about the species distribution and habitat requirements, nonlinear modelling was carried out to predict the presence/absence and density of the Eastern Iberian barbel, based on 155 sampling sites distributed throughout the Júcar River Basin District (Eastern Iberian Peninsula). We used multilayer feed-forward artificial neural networks (ANN) to represent nonlinear relationships between L. guiraonis descriptors and variables regarding the physical habitat and biological components (macroinvertebrates, fish, riparian forest). The gradient descent algorithm was implemented to find the optimal model parameters; the importance of the ANN’s input variables was determined by the partial derivatives method. The predictive power of the model was evaluated with the Cohen’s kappa (k), the correctly classified instances (CCI), and the area under the curve (AUC) of the receiver operator characteristic (ROC) plots. The best model predicted presence/absence with a high performance (k= 0.66, CCI= 87% and AUC= 0.85); the prediction of density was moderate (CCI = 62%, AUC=0.71 and k= 0.43). The fundamental variables describing the presence/absence were; solar radiation (the highest contribution was observed between 2000 and 4200 WH/m2), drainage area (with the strongest influence between 3000 and 5.000 km2), and the proportion of exotic fish species (with relevant contribution between 50 and 100%). In the density model, the most important variables were the coefficient of variation of mean annual flows (relative importance of 50.5%) and the proportion of exotic fish species (24.4%). The models provide important information about the relation of L. guiraonis with biotic and abiotic variables, this new knowledge can help develop future studies and management plans for the conservation of this species in the Júcar River Basin District and, potentially, for the conservation of other endemic fish species of Barbus and Luciobarbus in Mediterranean rivers.

scholarly journals Cytogenetic analyses of two endemic fish species from the São Francisco River basin: Conorhynchus conirostris and Lophiosilurus alexandri (Siluriformes)

2008 ◽  
Vol 31 (1 suppl) ◽  
pp. 215-221 ◽  
Author(s):  
Marilza Barbosa de Almeida Marques ◽  
Orlando Moreira-Filho ◽  
Caroline Garcia ◽  
Vladimir Pavan Margarido
Keyword(s):  
River Basin ◽  
Fish Species ◽  
Sao Francisco River ◽  
São Francisco River ◽  
Cytogenetic Analyses ◽  
Endemic Fish

scholarly journals Metahadzia Uncispina, A New Amphipod from Phreatic Ground-Waters of the Guadalquivir River basin of Southern Spain

1988 ◽  
Vol 58 (1) ◽  
pp. 79-87
Author(s):  
Jos Notenboom
Keyword(s):  
New Species ◽  
Iberian Peninsula ◽  
River Basin ◽  
Southern Spain ◽  
The South ◽  
Apical Spine ◽  
Ground Waters ◽  
Guadalquivir River ◽  
Original Concept

Metahadzia uncispina n. sp. is described, being the second species of the genus on the Iberian Peninsula. The new species, well characterized by the transformation of the apical spine on the endopodite of the male uropod 2, is undoubtedly closely related with M. tavaresi (Mateus & Mateus, 1972) from the south of Portugal. Comments are made about recent emendations of the original concept of the genus Metahadzia Stock, 1977.

Patterns of fish species richness in the Seine River basin, France

Hydrobiologia ◽  
1993 ◽  
Vol 259 (3) ◽  
pp. 157-167 ◽  
Author(s):  
Thierry Oberdorff ◽  
Eric Guilbert ◽  
Jean-Claude Lucchetta
Keyword(s):  
Species Richness ◽  
River Basin ◽  
Fish Species ◽  
Seine River ◽  
Seine River Basin

scholarly journals A description of mercury in fishes from the Madeira River Basin, Amazon, Brazil

2008 ◽  
Vol 38 (3) ◽  
pp. 431-438 ◽  
Author(s):  
Wanderley Rodrigues Bastos ◽  
Mauro de Freitas Rebelo ◽  
Márlon de Freitas Fonseca ◽  
Ronaldo de Almeida ◽  
Olaf Malm
Keyword(s):  
Body Weight ◽  
River Basin ◽  
Fish Species ◽  
Temporal Trends ◽  
Migratory Fish ◽  
Madeira River ◽  
Interspecies Variability ◽  
Total Hg ◽  
Madeira River Basin ◽  
Hg Accumulation

Over the last 20 years several projects carried on the Madeira River basin in the Amazon produced a great amount data on total Hg concentration in different fish species. In this paper we discuss temporal trends in Hg contamination and its relation to body weight in some of those fishes, showing that even within similar groups, such as carnivorous and non-migratory fish, the interspecies variability in Hg accumulation is considerable.

COMMERCIAL FAUNA OF WA-TERBODIES IN THE MOSCOW RIVER BASIN IN THE SECOND HALF OF THE 18th CENTURY

2021 ◽  
pp. 94-112
Author(s):  
N. Ozerova
Keyword(s):  
River Basin ◽  
Fish Species ◽  
18Th Century ◽  
Commercial Fish ◽  
Acipenser Ruthenus ◽  
Land Survey ◽  
Ancient Times ◽  
In The Beginning ◽  
Almost All ◽  
Moscow River

Based on the data from economic notes to the General Land Survey, the ranges of commercial fish and crayfish species that inhabited waterbodies of the Moscow River basin in the second half of the 18th century are reconstructed. Eighteen maps showing the distribution of 22 fish species, including Acipenser ruthenus L., Abramis brama L., Barbatula barbatula L., Lota lota L., Sander lucioperca L. and others are compiled. Comparison of commercial fish species that lived in the Moscow River basin in the second half of the 18th century with data from ichthyological studies in the beginning of the XXI century and materials of archaeological surveys shows that almost all of these species have lived in the Moscow River basin since ancient times and have survived to the present day.

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