Use este identificador para citar ou linkar para este item: https://repositorio.inpa.gov.br/handle/1/18286
Título: Hormonal and behavioral correlates of morphological variation in an Amazonian electric fish (Sternarchogiton nattereri: Apteronotidae)
Autor: Fernandes, Cristina Cox
Smith, G. Troy
Podos, Jeffrey
Nogueira, Adília
Inoue, LuÃ\xads Antônio Kioshi Aoki
Akama, Alberto
Ho, Winnie W.
Alves-Gomes, José Antônio
Palavras-chave: 11 Oxotestosterone
Androgen
Testosterone
Animals Experiment
Controlled Study
Electric Fish
Electric Organ
Female
Hormonal Regulation
Hormone Blood Level
Male
Nonhuman
Priority Journal
Reproduction
Seasonal Variation
Sex Difference
Tooth Development
Animal
Behavior, Animals
Body Size
Brasil
Electric Fish
Female
Gonadal Steroid Hormones
Health Status Indicators
Male
Seasons
Sex Characteristics
Data do documento: 2010
Revista: Hormones and Behavior
É parte de: Volume 58, Número 4, Pags. 660-668
Abstract: The weakly electric fish from the main channel of the Amazon river, Sternarchogiton nattereri, offers a striking case of morphological variation. Females and most males are toothless, or present only few minute teeth on the mandible, whereas some males exhibit exaggerated, spike-like teeth that project externally from the snout and chin. Androgens are known to influence the expression of sexually dimorphic traits, and might be involved in tooth emergence. In this study we assess the relationship in S. nattereri between morphological variation, 11 ketotestosterone (11-KT) and testosterone (T). We also examine relationships of morphology and androgen levels with electric organ discharge (EOD) frequency, reproductive condition, and seasonality. Our main finding is that male morph categories differed significantly in plasma concentrations of 11-KT, with toothed males showing higher levels of 11-KT than toothless males. By contrast, we did not detect statistical differences in T levels among male morph categories. Reproductive condition, as measured by gonadosomatic indexes (GSI), differed across two sample years, increased as the season progressed, and was higher in toothed males than in non-toothed males. EOD frequency was higher in toothed males than in either toothless males or females. Taken together, our findings suggest that S. nattereri male sexual characters are regulated by 11-KT levels, and that both morphology and androgens interact with reproductive condition and EOD frequency in ways that vary within and across reproductive seasons. © 2010 Elsevier Inc.
DOI: 10.1016/j.yhbeh.2010.06.006
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