scholarly journals REPRODUCTIVE CYCLE OF Leporinus copelandii (Pisces: Anostomidae) FEMALES FROM THE LOWER PARAÍBA DO SUL RIVER BASIN, RJ – BRAZIL

2015 ◽  
Vol 6 (2) ◽  
pp. 116
Author(s):  
Ana Paula Ribeiro Costa Erthal ◽  
Dalcio Ricardo Andrade ◽  
Marcella Costa Radael ◽  
Milton Erthal Junior ◽  
Eduardo Shimoda
Keyword(s):  
At Risk ◽  
River Basin ◽  
Reproductive Biology ◽  
Reproductive Cycle ◽  
Histological Study ◽  
Oocyte Development ◽  
Type Iv ◽  
Risk Of Extinction ◽  
Medium Diameter ◽  
Paraíba Do Sul River

The aim of this study were investigate the reproductive biology of the fish <em>Leporinus copelandii</em>, a specie at risk of extinction in the lower Paraíba do Sul River basin. During a period of 14 months, a total of 143 females of red-piau were captured, between Itaocara and Campos dos Goytacazes cities (RJ, Brazil). A histological study shows four stages of the oocyte development (I, II, III and IV) and five stages of the reproductive cycle of females: rest (1), initial maturation (2A), intermediary (2B), advanced (2C) and spawned (4) were identified. The pattern of <em>L. copelandii</em> oocyte development suggests development type synchronous in two groups, characterizing total spawning. Spawned females were captured in November, two months after the peak of frequency of competent females for reproduction. Histologically, a little occurrence of empty follicles was observed in spawned females. The medium diameter of the type IV oocyte of the spawned females (1475.1 ± 884.3mm) was significantly larger (Tukey, P &lt;0.001; VC = 41.73%; n = 259) than advanced maturation females (1202.6 ± 245.3mm), what allows suggesting that the study place probably doesn't represent the reproductive area of <em>L. copelandii</em>.

China's dhole population at risk of extinction

Science ◽  
2021 ◽  
Vol 372 (6541) ◽  
pp. 472.1-472
Author(s):  
Xiaoyang Wu ◽  
Qinguo Wei ◽  
Sai Deni ◽  
Honghai Zhang
Keyword(s):  
At Risk ◽  
Population At Risk ◽  
Risk Of Extinction

The anthropocene landscape and ecosystem services in the closure of sand mining: Paraíba do Sul River basin – Brazil

2021 ◽  
Vol 74 ◽  
pp. 102405
Author(s):  
Luciana Maria Ferrer ◽  
Daniel Andrés Rodriguez ◽  
Maria Cristina Forti ◽  
Felix Carriello
Keyword(s):  
Ecosystem Services ◽  
River Basin ◽  
Sand Mining ◽  
Paraíba Do Sul River

scholarly journals Cryopreservation of Brazilian orchid (Catasetum atratum Lindl.) seed at risk of extinction

2018 ◽  
Vol 12 (07) ◽  
pp. 1051-1057 ◽  
Author(s):  
Ana Beatryz Prenzier Suzuki ◽  
◽  
Thaís Cristina Morais Vidal ◽  
Guilherme Augusto Cito Alves ◽  
Douglas Bertoncelli Junior ◽  
...  
Keyword(s):  
At Risk ◽  
Risk Of Extinction

scholarly journals Distribution and reproductive biology of the Electric ray Discopyge tschudii Heckel, 1846 in San Matías Gulf, Northern Patagonia, Argentina

2011 ◽  
Vol 9 (4) ◽  
pp. 831-838 ◽  
Author(s):  
Marilú Estalles ◽  
Nidia Marina Coller ◽  
Edgardo Ernesto Di Giácomo ◽  
María Raquel Perier
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Biology ◽  
Reproductive Cycle ◽  
Southern Chile ◽  
Southern Brazil ◽  
Southwest Atlantic ◽  
Aggregate Distribution ◽  
Northern Patagonia ◽  
Southeast Pacific ◽  
Discopyge Tschudii

The Electric ray Discopyge tschudii is distributed in the Southwest Atlantic from southern Brazil to southern Argentina and in the Southeast Pacific from Peru to southern Chile. The main threat to this species is fishing. Discopyge tschudii is noncommercial and individuals caught are discarded on board. The present study analyzes the distribution and the morphological and reproductive characteristics of this ray in San Matías Gulf (SMG), Argentina. A total of 1087 individuals were analyzed. The species presented an aggregate distribution, with the main concentrations in the northern and eastern areas of SMG, at depths below 100 m. Males ranged from 9 to 43 cm and females from 11 to 38 cm. The species presented sexual dimorphism. Males were larger and heavier than females and also matured at larger sizes. Size at 50% of maturity was estimated at 30 cm for males and 21 cm for females. A total of 199 embryos were sampled and the proportion of sexes showed no significant differences from the expected 1:1. The number of embryos per female varied from 1 to 12. The most frequent values were 2 and 5. Length at birth was estimated at 82.17 ± 3.87 mm. Based on our findings, we hypothesize that the electric ray D. tschudii completes its reproductive cycle in SMG.

scholarly journals Reproductive biology of Rhaphiodon vulpinus (Ostariophysi: Cynodontidae) in the Tocantins River Basin, Brazil

2007 ◽  
Vol 5 (4) ◽  
pp. 479-484 ◽  
Author(s):  
Andréa L. Neuberger ◽  
Elineide E. Marques ◽  
Carlos S. Agostinho ◽  
Rafael J. de Oliveira
Keyword(s):  
River Basin ◽  
Reproductive Biology ◽  
Mean Value ◽  
Reproductive Period ◽  
Total Weight ◽  
Individual Female ◽  
Relative Fecundity ◽  
Mean Diameter ◽  
Tocantins River ◽  
The Individual

In order to evaluate aspects of the reproductive biology of Rhaphiodon vulpinus in the Upper and Middle Tocantins River, samples were taken monthly from October, 1999 through September, 2001, by means of gill nets. Males, which were more abundant than females (chi2 146.87: df=1: p<0.05), matured at a smaller size. The reproductive period of the species extended essentially from November through January, with a peak of activity in November. Fecundity, with an estimated mean value of 98,185 oocytes, varied from 38,177 to 215,841 oocytes, and it did not correlate with the length of the individual female analyzed (r=0.4663: p=0.206). Relative fecundity was 130.6 oocytes/g total weight. Mature oocytes had a mean diameter of 0.98 mm, corresponding to a volume of 0.50 mm³.

Gene mapping of 5S rDNA sites in eight fish species from the Paraíba do Sul river basin, Brazil

2004 ◽  
Vol 106 (1) ◽  
pp. 107-110 ◽  
Author(s):  
K.F. Kavalco ◽  
R. Pazza ◽  
L.A.C. Bertollo ◽  
O. Moreira-Filho
Keyword(s):  
Gene Mapping ◽  
River Basin ◽  
Fish Species ◽  
5S Rdna ◽  
Rdna Sites ◽  
Paraíba Do Sul River

Zooplankton community of sand pits of Paraiba do Sul River basin, São Paulo, Brazil

1998 ◽  
Vol 26 (4) ◽  
pp. 1524-1528
Author(s):  
Maria Aparecida Juliano de Carvalho ◽  
Suzana Sendacz
Keyword(s):  
River Basin ◽  
Zooplankton Community ◽  
Sao Paulo ◽  
São Paulo ◽  
Sand Pits ◽  
Paraíba Do Sul River

scholarly journals Ovarian Histomorphology and Gonadial Cycle of Freshwater Garfish Xenentodon cancila (Hemilton-Buchanan) (Beloniformes:Belonidae)

BIBECHANA ◽  
1970 ◽  
Vol 8 ◽  
pp. 96-104
Author(s):  
Bharat Raj Subba ◽  
Satya Narayan Meheta
Keyword(s):  
Reproductive Cycle ◽  
Oocyte Development ◽  
Fish Pass ◽  
Early Maturing ◽  
Xenentodon Cancila ◽  
Pass Through ◽  
One Year

The histomorphology and gonadial cycle of a freshwater garfish Xenentoton cancila revealed that the ovaries of the fish pass through resting, early maturing advanced maturing, pre-spawning, spawning and spent phases within one year. The oogenetic activity starts in November and continues upto June(GSI=10.19)-July(GSI=11.38), when ovaries are full of yolky eggs. Only young oogonia and oocytes l appeared in September to October. The oocytes of l,ll,lll,lV and V stages were present during November to February. The oocytes Vl and Vll were seen dominated by ripe oocytes during June to late July when spawning takes place. Asychronism mode of oocyte development was recorded in X.cancila. Keywords: Xenentodon cancila; oocyte development; reproductive cycle; spawningDOI: http://dx.doi.org/10.3126/bibechana.v8i0.5694  BIBECHANA 8 (2012) 96-104

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