Reproductive allocation by Amazon fishes in relation to feeding strategy and hydrology
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Seasonal environments favor the evolution of capital breeding, whereby reproduction uses surplus energy from resources acquired during an earlier period. Consequently, reproductive effort in capital breeders is expected to depend on traits associated with energy storage rather than environmental conditions at the time of reproduction. Based on a 15-year dataset, we investigate the effect of phenotype (body size and condition) and environmental conditions (intensity of hydrological seasons, predator density, and density of conspecifics) on fecundity three capital breeding fish species from the strongly seasonal Amazon River floodplain: Psectrogaster rutiloides, Triportheus angulatus, and Acestrorhynchus falcirostris. Fecundity of all three species was strongly correlated with phenotype and modulated by unfavorable environmental conditions during the period of reproduction, especially high density of conspecifics. Fecundity was negatively affected by the density of conspecifics for small females of A. falcirostris, and for T. angulatus females with poor body condition. Fecundity of P. rutiloides declined during periods of drought when density of conspecifics was highest. A clear tradeoff between quantity and quality of oocytes was found only for P. rutiloides. This study highlights that reproductive allocation of capital breeders in seasonal environments is strongly linked to environmental conditions before and during the reproductive period.
KeywordsCosts of reproduction Context-dependent investment Body condition Density dependence Environmental conditions Tradeoff
We thank the students, volunteers, fishermen, and Raimundo Sotero who helped in the field and laboratory over more than one decade of study. We also thank the two anonymous reviewers and Joel Trexler for their valuable comments.
CPR, KW, and SA conceived the idea; CPR, DWF, CPD, and SA obtained the data; CPR and THSP analyzed the data; CPR, THSP, and KW wrote the manuscript; and all authors provided editorial advice. All authors contributed significantly to the paper and approved the submitted version.
This study was funded by the Amazonas State Research Funding Agency (FAPEAM 062003342013), Brazilian National Council for Scientific and Technological Development (CNPq) (575738/2008-1), National Institute for Amazonian Research (INPA), and US National Science Foundation (DEB 1257813). CPR, THSP, and DDWF received fellowships from CNPq and/or Brazilian Federal Agency for Support and Evaluation of Graduate Education (CAPES).
Compliance with ethical standards
Conflict of interest
The authors declare they have no conflict of interest.
All applicable institutional guidelines for the care and use of animals were followed, INPA’s ethics committee rules (Protocol Number 33/2012). Fish surveys were authorized by IBAMA through license #101932, and followed.
- Barthem, R. B. & N. N. Fabré, 2004. Biologia e diversidade dos recursos pesqueiros da Amazônia, p. 17–62. In: Ruffino, M.L. (coord.). A pesca e os recursos pesqueiros na Amazônia brasileira. Ibama/Provárzea, Manaus, Brasil, 268 pp.Google Scholar
- Breheny, P. & W. Burchett, 2017. Visualizing Regression Models Using Visreg. https://journal.r-project.org/archive/2017/RJ-2017-046/index.html
- Correia, G. B., F. K. Siqueira-Souza & C. E. C. Freitas, 2014. Intra- and inter-annual changes in the condition factors of three Curimatidae detritivores from Amazonian floodplain lakes. Biota Neotropica 1: 7–15.Google Scholar
- Ferreira, E., J. Zuanon & G. M. Santos, 1998. Peixes Comerciais do Médio Amazonas Região de Santarém—PA. IBAMA, Brasília: 211 p.Google Scholar
- Junk, W. J., 1985. Temporary fat storage, an adaptation of some fish species to the river level fluctuations and related environmental changes of the Amazon River. Amazoniana 9: 315–351.Google Scholar
- Junk, W. J., P. B. Bayley & R. E. Sparks, 1989. The flood pulse concept in river—floodplain systems. Special Publication of the Canadian Journal of Fisheries and Aquatic Sciences 106: 10–127.Google Scholar
- R Development Core Team, 2016. R: a language and environment for statistical computing R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0. http://www.R-projectorg
- Stearns, S. C., 1992. The Evolution of Life Histories. Oxford University Press, Oxford.Google Scholar