Reproductive biology of a characidiinae (osteichthyes, characidae) from the Ubatiba river, Maricá -- RJ
The Ubatiba river is a coastal stream subject to stochastic spates all over the year and, Characidium sp.n. is among the twenty-two species that compose its ichthyofauna. In this study we analyse some traits of its reproductive biology and discuss whether the adopted strategy has causal relationship...
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| Format: | Article |
| Language: | English |
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Instituto Internacional de Ecologia
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| Series: | Brazilian Journal of Biology |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-69842002000300013&lng=en&tlng=en |
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| author | R. MAZZONI E. P. CARAMASCHI N. FENERICH-VERANI |
| author_facet | R. MAZZONI E. P. CARAMASCHI N. FENERICH-VERANI |
| author_sort | R. MAZZONI |
| collection | DOAJ |
| description | The Ubatiba river is a coastal stream subject to stochastic spates all over the year and, Characidium sp.n. is among the twenty-two species that compose its ichthyofauna. In this study we analyse some traits of its reproductive biology and discuss whether the adopted strategy has causal relationship with the environmental variables. Specimens were collected in the upper Ubatiba river. Samplings, were carried out monthly by electrofishing, between Oct./94 and Sep./95. Some differences between male and female strategies were observed. Females were significantly (p < 0.05) bigger than males; length -- weight relationship was different (p < 0.05) between sexes with the onset of sexual maturity occuring at smaller sizes among males. Reproductive investment is high for both males and females but higher for males, maximum Gonadosomatic Index for females and males were 40.97% and 44.90%, respectively. Reproductive specimens were registered all over the year, suggesting continuous reproduction. High values of fecundity were also registered varying from 1342 to 5535 eggs for ripe females of 4.4 and 7.0 cm, respectively and an amount of 1105 oocytes per grams of fish. We suggest that differences in the reproductive strategy, between sexes, determine the observed patterns in the size structure; the absence of males in the higher SL classes could be a consequence of high mortality rates and/or reduction in the growth rates as a precocity consequence in the onset of reproduction and/or high reproductive investment. Relationship between continuous reproduction and environmental condition could be explained as an adaptation to maximise supervivency of the young fishes that is: guarantee the species maintenance in a stochastic environment. |
| first_indexed | 2024-12-23T03:59:20Z |
| format | Article |
| id | doaj.art-2c3ef880c4e9415f8793ad4ac2b93038 |
| institution | Directory Open Access Journal |
| issn | 1678-4375 |
| language | English |
| last_indexed | 2024-12-23T03:59:20Z |
| publisher | Instituto Internacional de Ecologia |
| record_format | Article |
| series | Brazilian Journal of Biology |
| spelling | doaj.art-2c3ef880c4e9415f8793ad4ac2b930382022-12-21T18:00:46ZengInstituto Internacional de EcologiaBrazilian Journal of Biology1678-437562348749410.1590/S1519-69842002000300013S1519-69842002000300013Reproductive biology of a characidiinae (osteichthyes, characidae) from the Ubatiba river, Maricá -- RJR. MAZZONI0E. P. CARAMASCHI1N. FENERICH-VERANI2Universidade do Estado do Rio de JaneiroUniversidade Federal do Rio de JaneiroUniversidade Federal de São CarlosThe Ubatiba river is a coastal stream subject to stochastic spates all over the year and, Characidium sp.n. is among the twenty-two species that compose its ichthyofauna. In this study we analyse some traits of its reproductive biology and discuss whether the adopted strategy has causal relationship with the environmental variables. Specimens were collected in the upper Ubatiba river. Samplings, were carried out monthly by electrofishing, between Oct./94 and Sep./95. Some differences between male and female strategies were observed. Females were significantly (p < 0.05) bigger than males; length -- weight relationship was different (p < 0.05) between sexes with the onset of sexual maturity occuring at smaller sizes among males. Reproductive investment is high for both males and females but higher for males, maximum Gonadosomatic Index for females and males were 40.97% and 44.90%, respectively. Reproductive specimens were registered all over the year, suggesting continuous reproduction. High values of fecundity were also registered varying from 1342 to 5535 eggs for ripe females of 4.4 and 7.0 cm, respectively and an amount of 1105 oocytes per grams of fish. We suggest that differences in the reproductive strategy, between sexes, determine the observed patterns in the size structure; the absence of males in the higher SL classes could be a consequence of high mortality rates and/or reduction in the growth rates as a precocity consequence in the onset of reproduction and/or high reproductive investment. Relationship between continuous reproduction and environmental condition could be explained as an adaptation to maximise supervivency of the young fishes that is: guarantee the species maintenance in a stochastic environment.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-69842002000300013&lng=en&tlng=enCharacidiinaecoastal streamreproductive biology |
| spellingShingle | R. MAZZONI E. P. CARAMASCHI N. FENERICH-VERANI Reproductive biology of a characidiinae (osteichthyes, characidae) from the Ubatiba river, Maricá -- RJ Brazilian Journal of Biology Characidiinae coastal stream reproductive biology |
| title | Reproductive biology of a characidiinae (osteichthyes, characidae) from the Ubatiba river, Maricá -- RJ |
| title_full | Reproductive biology of a characidiinae (osteichthyes, characidae) from the Ubatiba river, Maricá -- RJ |
| title_fullStr | Reproductive biology of a characidiinae (osteichthyes, characidae) from the Ubatiba river, Maricá -- RJ |
| title_full_unstemmed | Reproductive biology of a characidiinae (osteichthyes, characidae) from the Ubatiba river, Maricá -- RJ |
| title_short | Reproductive biology of a characidiinae (osteichthyes, characidae) from the Ubatiba river, Maricá -- RJ |
| title_sort | reproductive biology of a characidiinae osteichthyes characidae from the ubatiba river marica rj |
| topic | Characidiinae coastal stream reproductive biology |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-69842002000300013&lng=en&tlng=en |
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