scholarly journals Biological aspects of Schizodon nasutus Kner, 1858 (Characiformes, Anostomidae) in the low Sorocaba river basin, São Paulo state, Brazil

2011 ◽  
Vol 71 (3) ◽  
pp. 763-770 ◽  
Author(s):  
GA. Villares Junior ◽  
LM. Gomiero ◽  
R. Goitein
Keyword(s):  
River Basin ◽  
Condition Factor ◽  
Feeding Activity ◽  
Gonadosomatic Index ◽  
Sao Paulo ◽  
Reproductive Period ◽  
Fish Diet ◽  
São Paulo ◽  
Summer Period ◽  
Biological Aspects

Four biological aspects of Schizodon nasutus in the low Sorocaba river basin, São Paulo, Brazil were analysed. These were accomplished during the year seasons. The fish diet and the feeding activity were investigated by studying the repletion index, which showed no significant differences between seasons. The food items analysed by frequency of occurrence and dominance showed a predominance of vegetable items in the diet. The reproduction, analysed by using the gonadosomatic index, indicated that the reproductive period occurs during the summer period when temperatures are higher and rainfalls are more intense. The amount of accumulated fat and condition factor varied according to reproduction, especially for females.

Arsenic in terrestrial invertebrates from riparian areas of the Piracicaba River Basin, São Paulo State, Brazil

2017 ◽  
Vol 314 (3) ◽  
pp. 1675-1681
Author(s):  
Elvis J. França ◽  
Elisabete A. De Nadai Fernandes ◽  
Felipe Y. Fonseca ◽  
Marcelo R. L. Magalhães ◽  
Mariana L. O. Santos
Keyword(s):  
River Basin ◽  
Sao Paulo ◽  
São Paulo ◽  
Riparian Areas ◽  
Terrestrial Invertebrates ◽  
Paulo State ◽  
São Paulo State ◽  
Piracicaba River

scholarly journals Induced reproduction in a migratory teleost species by water level drawdown

2015 ◽  
Vol 13 (1) ◽  
pp. 205-212 ◽  
Author(s):  
Chayrra Chehade ◽  
Mônica Cassel ◽  
Maria Inês Borella
Keyword(s):  
Environmental Factors ◽  
Water Level ◽  
Gonadosomatic Index ◽  
Hormonal Treatment ◽  
Fish Farming ◽  
Sao Paulo ◽  
Morphological Description ◽  
Advanced Stage ◽  
São Paulo ◽  
Sample Period

Captive reproduction is one of the problems faced in aquaculture requiring the manipulation of environmental factors and/or hormonal treatment. Thus, we seek to verify experimentally which gonadal changes were present in mature individuals of Astyanax altiparanae arising from decreased water level. Collections were made every four hours, initiated four hours before and finished 28 hours after stimulation, at the Fish Farming Station of Companhia Energética de São Paulo, São Paulo, Brazil. The gonads were analyzed by light microscopy. The females had ovaries in the spawning capable phase until 12h; in 16h, in a more advanced stage of spawning capable phase; and, from 20h, in the regressing phase. Males had testes in the spawning capable phase until 8h; in 12h, in a more advanced stage of spawning capable phase; and, from 16h, the return to the spawning capable phase. The morphological description was corroborated by the proportion of cell classes. Females presented variation on the gonadosomatic index, but it was not found an emptying of the gonad for neither sex. The process of inducing reproduction with water level drawdown was considered satisfactory, since both sexes presented a reduction in the number of mature gametes at the end of the sample period.

scholarly journals Invasive non-native species of fish in upper Paraná river Basin, Brazil: variations of caloric content in Cichla kelberi

2012 ◽  
Vol 10 (2) ◽  
pp. 401-408 ◽  
Author(s):  
Luis Alberto Espínola ◽  
Horácio Ferreira Júlio Junior ◽  
Evanilde Benedito
Keyword(s):  
Native Species ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Reproductive Period ◽  
Paraná River ◽  
Caloric Content ◽  
Fish Food ◽  
Gonadal Maturation ◽  
Parana River ◽  
Upper Paraná River

The allocation of assimilated energy may be influenced by seasonal changes, growth, and reproductive cycle of fish, food consumption and environmental conditions. The objective of this research was to evaluate the energetic variations of Cichla kelberi in the upper Paraná River floodplain, analyzing the caloric content in muscles, gonadosomatic index (GSI), and the condition factor between assessed systems, sex, and stage of gonadal maturation. The results obtained in the present study permit assuring that this is a species that efficiently converts the resources of the environment into energy. Although presenting higher condition factor in the environment where there is a greater ease in getting food (Paraná subsystem), the energy identified in the muscles was the same in both subsystems. During the process of gonadal maturation there is optimization in energy accumulation in the muscles of females, before and after reproductive period, and somatic growth occurs significantly when the individual is not reproducing. Further detailed studies on ecological mechanisms influencing the success of the species, as the presence of competitors and preference for native preys, are needed to implement effective management measures aimed at preventing that the species proliferation in the environment is even more damaging to local biodiversity.

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 Reproduction of the catfish Iheringichthys labrosus (Lütken) (Pisces, Siluriformes) in Furnas reservoir, Minas Gerais, Brazil

2004 ◽  
Vol 21 (2) ◽  
pp. 193-200 ◽  
Author(s):  
José Enemir dos Santos ◽  
Nilo Bazzoli ◽  
Elizete Rizzo ◽  
Gilmar Bastos Santos
Keyword(s):  
Feeding Activity ◽  
Gonadosomatic Index ◽  
Secretory Activity ◽  
Minas Gerais ◽  
Reproductive Period ◽  
Mature Stage ◽  
Hepatosomatic Index ◽  
Gonadal Maturation ◽  
Caudal Region ◽  
Iheringichthys Labrosus

The reproductive biology of Iheringichthys labrosus (Lütken, 1874) was studied in Furnas reservoir, Minas Gerais, Brazil. The fishes, 323 males and 817 females, were captured bimonthly from August 1993 to July 1994 by using gill nets with 3-10 cm mesh size. Gonadal maturation of the specimens was analyzed through macro and microscopical characteristics of the gonads. The secretory activity of the tubules of the caudal region of the testis was analyzed during the maturational testicular cycle. Females and males were in reproductive activity throughout the year in the reservoir. The peak of advanced maturation/mature stages occurred from October to January and of spawned/spent from February to May. The spawning of I. labrosus was identified as fractional or multiple type: occurring in the reservoir or in tributaries around it. The oocyte development of the species was asynchronous as different clusters of oocytes occurred simultaneously in the ovarian parenchyma. The epithelium of the tubules of the caudal region of the testis was in high secretory activity during advanced maturation/mature stage and this activity was absence in resting. The gonadosomatic index followed gonadal maturation, and the hepatosomatic index of females was lowest in advanced maturation/mature probably due the contribution of the liver in the vitellogenesis. The variations of the stomach repletion index, coelomic fat and condition factor indicated that the feeding activity was reduced and that the energetic reserves were consumed during the reproductive period.

scholarly journals Reproductive indicators of the endemic species Astyanax bifasciatus (Teleostei: Characidae) in a tributary of the Lower Iguaçu River Basin, Brazil

2019 ◽  
Vol 41 ◽  
pp. e47720
Author(s):  
Elton Celton de Oliveira ◽  
Alexandre Augusto Auache-Filho ◽  
Denis Damasio ◽  
Nédia de Castilhos Ghisi ◽  
Maria Antônia Michels-Souza
Keyword(s):  
River Basin ◽  
Fish Species ◽  
Sexual Maturity ◽  
Gonadosomatic Index ◽  
Reproductive Period ◽  
Maturity Stage ◽  
Reproductive Process ◽  
Maturation Stages ◽  
High Degree ◽  
Iguaçu River

The reproductive process promotes morphophysiological and behavioral changes in fish species throughout their life cycle. Its success is vital to define their resilience in the environment. This study aimed to evaluate the reproductive biology of the endemic fish species Astyanax bifasciatus in a tributary of the Lower Iguaçu River Basin, Paraná, Brazil. Fish were collected monthly at four sites along the Jirau Alto River in the city of Dois Vizinhos from October 2015 to September 2016. A standardized catch effort with gill nets and fish traps was used. In the laboratory, standard length and total weight were recorded. After anesthesia, the animals were sectioned to macroscopically determine the sex, sexual maturity stage, and presence of celomatic fat. The gonads and liver were removed to determine the gonadosomatic and hepatosomatic indexes, respectively. A total of 160 individuals (104 females and 56 males) were used. The gonadosomatic index, frequency of the gonadal maturation stages, and condition factor showed a long reproductive period with two investment cycles for both sex. Length at first sexual maturity was 4.57 cm for females and 3.56 cm for males. The reproductive data corroborate the generalist profile of the species and demonstrate a high degree of adaptive capacity, even in smaller tributaries.

Analysis of fish communities along a rural–urban gradient in a neotropical stream (Piracicaba River Basin, São Paulo, Brazil)

Hydrobiologia ◽  
2010 ◽  
Vol 641 (1) ◽  
pp. 97-114 ◽  
Author(s):  
Cleber Valim Alexandre ◽  
Katharina Eichbaum Esteves ◽  
Mônica Accaui Marcondes de Moura e Mello
Keyword(s):  
River Basin ◽  
Fish Communities ◽  
Sao Paulo ◽  
São Paulo ◽  
Urban Gradient ◽  
Neotropical Stream ◽  
Piracicaba River

scholarly journals Protozooplankton and its relationship with environmental conditions in 13 water bodies of the Mogi-Guaçu basin - SP, Brazil

2013 ◽  
Vol 13 (4) ◽  
pp. 152-163 ◽  
Author(s):  
Inessa Lacativa Bagatini ◽  
Ana Lúcia Gerardi Spínola ◽  
Bianca de Miranda Peres ◽  
Adrislaine da Silva Mansano ◽  
Mafalda Alexandra Antunes Rodrigues ◽  
...  
Keyword(s):  
Environmental Variables ◽  
Sao Paulo ◽  
Water Bodies ◽  
Bromophenol Blue ◽  
São Paulo ◽  
Paulo State ◽  
Two Samples ◽  
São Paulo State ◽  
Biological Aspects ◽  
The Mean

Protozooplankton is an important component of the aquatic microbial food webs and its composition, density, and distribution reflect the chemical, physical, and biological aspects of the environment. Considering the scarce literature on freshwater protozoans in Brazil and on protozoan ecology in subtropical environments, we listed the ciliates and amoebae taxa found in 13 water bodies in São Paulo State and analyzed their abundance in relation to the environmental variables. We collected two samples in each environment, fixed immediately with mercuric chloride and stained with bromophenol blue. After microscopical analysis, 74 protozoan genera were identified and the Ciliophora were dominant in the majority of the environments. The Stichotrichia, represented mostly by the genus Halteria, occurred in all environments, and was the dominant subclass in five of them. The canonic correspondence analysis of the most frequent genera and the environmental variables showed that nitrite and nitrate were the variables that better explained the distribution of Limnostrombidium, Urotricha, and Vorticella. The densities of the genera Halteria, Coleps, and of the species Cinetochilum margaritaceum were positively affected by increasing concentrations of dissolved oxygen, particulate phosphate, conductivity, and temperature. C. margaritaceum were also negatively affected by increasing concentrations of nitrite and nitrate. Considering that we made only one sampling in each environment, the richness was high compared to the mean diversity of lakes in the São Paulo State. The Diogo Lake, located in an ecological reserve, was the richest one, confirming the need of more research on the biodiversity of more preserved environments.

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