Energy acquisition and allocation to egg production in relation to fish reproductive strategies

Abstract

Oogenesis in fishes follows a universal plan; yet, due to differences in the synchrony and rate of egg development, spawning frequency varies from daily to once in a lifetime. Some species spawn and feed in separate areas, during different seasons, by storing energy and drawing on it later for reproduction (i.e. capital breeding). Other species spawn using energy acquired locally, throughout a prolonged spawning season, allocating energy directly to reproduction (i.e. income breeding). Capital breeders tend to ovulate all at once and are more likely to be distributed at boreal latitudes. Income breeding allows small fish to overcome allometric constraints on egg production. Income breeders can recover more quickly when good‐feeding conditions are re‐established, which is a benefit to adults regarding bet‐hedging spawning strategies. Many species exhibit mixed capital‐ and income‐breeding patterns. An individual's position along this capital–income continuum may shift with ontogeny or in relation to environmental conditions, so breeding patterns are a conditional reproductive strategy. Poor‐feeding environments can lead to delayed maturation, skipped spawning, fewer spawning events per season or fewer eggs produced per event. In a few cases, variations in feeding environments appear to affect recruitment variability. These flexible processes of energy acquisition and allocation allow females to prioritize their own condition over their propagules' condition at any given spawning opportunity, thereby investing energy cautiously to maximize lifetime reproductive value. These findings have implications for temporal and spatial sampling designs, for measurement and interpretation of fecundity, and for interpreting fishery and ecosystem assessments.

More Than Just a Spawning Location: Examining Fine Scale Space Use of Two Estuarine Fish Species at a Spawning Aggregation Site

“…Species that spend weeks to months at spawning aggregation sites likely must rely on energy resources from the spawning site or adjacent habitats, to sustain reproduction throughout the spawning season (Lowerre-Barbieri et al, 2011;McBride et al, 2015; and reviewed in Sadovy de Mitcheson and Colin, 2012). Aggregating fish with protracted spawning season's use of spawning sites and adjacent foraging habitats may be contrasted to nesting migratory birds that require abundant prey near nesting sites to feed chicks (Both and Visser, 2001).…”

“…On the leeward side of the pass where spawning occurs, a productive seagrass meadow exists which could act as a key foraging habitat for spawning fish that would allow them to overcome body size constraints on egg production, which may result in different spawning behaviors than what would be expected from total spawners (i.e., Nassau Grouper Epinephelus striatus; Bolden, 2000). Based on previous work on spawning aggregations (see Sadovy de Mitcheson and Colin, 2012), we hypothesize that spawning fish of both species would use both the spawning inlet and the seagrass habitat during the spawning season due to mechanisms related to spawning (inlet use) and foraging (seagrass use; McBride et al, 2015). To test our hypothesis, we applied both network analysis and more traditional analytical techniques to telemetry observations.…”

“…When these spawning aggregations reach a low-density threshold of individuals where reproduction there ceases to contribute to the population, the fishery associated with that stock often crashes (Sadovy and Domeier, 2005). Given the biological importance of these sites, developing conservation strategies aimed at protecting the functions of those locations and the spawning fish there, are crucial to maintaining the sustainability of marine fisheries (Sadovy de Mitcheson and Colin, 2012).Species that spend weeks to months at spawning aggregation sites likely must rely on energy resources from the spawning site or adjacent habitats, to sustain reproduction throughout the spawning season (Lowerre-Barbieri et al, 2011;McBride et al, 2015; and reviewed in Sadovy de Mitcheson and Colin, 2012). Aggregating fish with protracted spawning season's use of spawning sites and adjacent foraging habitats may be contrasted to nesting migratory birds that require abundant prey near nesting sites to feed chicks (Both and Visser, 2001).…”

Spatiotemporal variation in flow-dependent recruitment of long-lived riverine fish: Model development and evaluation

“…Variation in energy intake among individuals and species can result in a range of energy investment strategies for reproduction (McBride et al, 2013). For instance, floods and droughts can reduce foraging efficiency of drift-feeding fishes, subsequently reducing energy availability for growth and gonad development (Collins and Anderson, 1999;Encina and Granado-Lorencio, 1997).…”

Health and reproduction of red mullet, Mullus barbatus, in the western Mediterranean Sea

“…Thus, spawning strategies may be flexible within species and may depend on the availability of food. There is a well-documented distinction between capital breeders and income breeders, but there are also species that use a variety of mixed-breeding strategies (Houston et al, 2006;McBride et al, 2013). It seems probable that some species of fish may be capable of adopting either a capital or income strategy, or a blend of both in response to internal or external conditions.…”