River hydrological seasonality influences life history strategies of tropical riverine fishes

Abstract

Under a particular set of selective forces, specific combinations of traits (strategies) will be favored in a given population, within the particular constraints of the considered species. For fishes, three demographic strategies have been suggested to result from adaptive responses to environmental predictability (i.e., seasonality): periodic, opportunistic and equilibrium [Winemiller KO, Rose KA (1992) Patterns of life-history diversification in North American fishes: implications for population regulation. Can J Fish Aquat Sci 49:2196-2218]. These strategies optimize fitness within predictable, unpredictable and stable systems, respectively. We tested these predictions of life history trait distribution along a gradient of hydrologic seasonality in West African tropical rivers at the drainage basin scale. We used logistic regression of species presence-absence data to test whether dominant life history traits of species caused community compositional change in response to a gradient of seasonality in hydrologic regime across basins. After accounting for taxonomic relatedness, species body size and statistical redundancy inherent to related traits, we found a higher proportion of species producing a great number of small oocytes, reproducing within a short period of time and presenting a low degree of parental care (the periodic strategy) in highly seasonal drainage basins (e.g., rivers with a short and predictable favorable season). Conversely, in more stable drainage basins (e.g., rivers with a wet season of several months), we observed a greater proportion of species producing small numbers of large oocytes, reproducing within a long period of time and providing parental care to their offspring (the equilibrium strategy). Our results suggest that distributions of tropical freshwater fishes at the drainage basin scale can be partly explained by the match between life history strategies and seasonality gradients in hydrological conditions.

Reproductive ecology of Odontostilbe pequira (Steindachner, 1882) (Characidae, Cheirodontinae) in the Paraguay River, southern Pantanal, Brazil

“…Nevertheless, the reproductive activity is intensified in June and July followed by December and January, and in some months there is a decrease in the proportion of reproducing females. The long reproductive period was also found by various authors in small-sized species (Mazzoni et al 2002(Mazzoni et al , 2005Hojo et al 2004), but not corresponding with a reproductive strategy for seasonal environments (Munro 1990;Vazzoler and Menezes 1992), characterized by species with a short reproductive period associated with the favorable conditions of flooding (Tedesco et al 2008), as reported for Moenkhausia sanctaefilomenae in the northern Pantanal (Lourenço et al 2008a). Furthermore, the long reproductive period shows a intraspecific variation in O. pequira, once Oliveira et al (2010) in studying the reproductive period of the same species in southern Brazil (sub-tropical region) found two reproductive steps, from September to October and from January to February.…”

“…In fishes, a wide diversity in traits and patterns of life history has been documented (Winemiller 1989;Wootton 1998;Hutchings 2002;King et al 2003), which by way of high phenotypic plasticity varies intra-and interspecifically in response to environmental factors (Pampoulie et al 2000;Blanck and Lamouroux 2007;Tedesco et al 2008;Mérona et al 2009), altering size, growth, mortality, age and reproductive period (Wootton 1998;Lowe-McConnel 1999).…”

The role of ecological strategies in the colonization success of pelagic fish in a large tropical reservoir (Petit-Saut Reservoir, French Guiana)

“…The change in hydrological variability, a parameter known to significantly affect the representation of mean life history traits in fish communities (Tedesco et al 2008), was one of the most prominent transformations in the Petit-Saut Reservoir after its filling. Fish in the Sinnamary River before damning experienced large stochastic variations in discharge and water level and, as a consequence, opportunistic/periodic strategies dominated the community (Ponton and Mérona 1998).…”

Short-term movement of barramundi in a ­seasonally closed freshwater habitat

“…Balcombe et al 2006). Tedesco et al (2008) also reported that floodplain inun dation can enhance recruitment by improving the feeding environment for larvae, resulting in clear responses to hydrological seasonality in tropical river populations. Thus, in the warm season prey may be more abundant or move more on the currents of flowing water, allowing freshwater predators to remain in one location and ambush prey that move into or through an area.…”