Filial cannibalism in a nest-guarding fish: females prefer to spawn in nests with few eggs over many

Abstract

In fish, fecundity correlates with female body size and egg-tending males often eat small broods. Therefore, small females may prefer to spawn in nests that already contain many eggs, to ensure the brood is as large as possible.In contrast, large females may prefer nests with few eggs, if high egg number or density has a negative effect on egg survival, or if there are drawbacks of spawning last in a nest. To test the hypothesis that female body size affects nest (and male mate) choice, using the sand goby (Pomatoschistus minutus), we allowed small and large females to choose between two males that were matched in size -one guarding a small clutch and the other a large clutch, respectively. We recorded where females spawned (measure of female preference), the combined brood size, male courtship, egg care and nest building. We also quantified the effect of brood size and egg density on egg survival in a separate data set. Although the combined broods did not exceed the small brood sizes that are at risk of being eaten, both small and large females preferred to spawn in nests with smaller clutch sizes. This preference could not be explained by more courtship or male parental effort, nor by reduced survival of larger or denser broods. Instead, our result might be explained by females avoiding the danger of cannibalism of young eggs by males or the risk of reduced egg health associated with being near the nest periphery.

Ecological variation along the salinity gradient in the Baltic Sea Area and its consequences for reproduction in the common goby

“…This might explain why only 60% of nest holding males received eggs at IP, but all of these males were guarding large broods (suggesting clutches of 2 or more females). However, the expression of a preference for nests that already contain eggs may also vary across populations ( Andren and Kvarnemo 2014 ). Females originating from TV showed a preference for empty nests even under experimentally manipulated levels of female mate competition (Heubel KU, submitted for publication).…”

Female mating competition alters female mating preferences in common gobies

“…1985 ; Sargent 1988 ; Petersen and Marchetti 1989 ; Vallon and Heubel 2017 ). Alternatively, females may prefer males with empty nests or nests that only contain fewer eggs to avoid being the last ( Andrén and Kvarnemo 2014 ). The last added clutch bears the highest risk of filial cannibalism ( Salfert and Moodie 1985 ; Petersen and Marchetti 1989 ; Klug and Lindström 2008 ; Vallon and Heubel 2016 ).…”

“…1996a ; Requena and Machado 2015 ). However, it is still not well understood why such preferences exist and how they change in a competitive environment ( Lehtonen and Lindström 2009 ; Lindström and Lehtonen 2013 ) or otherwise challenging environment or social context (forced mating versus free mate choice: Lindström and Kangas 1996 ; supply of oxygen: Reynolds and Jones 1999 ; filial cannibalism and female body size: Andrén and Kvarnemo 2014 ; reviewed: Qvarnström 2001 ; Wong and Candolin 2005 ).…”

Going all the way: The implications of life history and phenotype on reproductive success of the common triplefin, Forsterygion lapillum

“…However, dominant males still received matings by limiting female access to the "good fathers". In a similar scenario, females may prefer to mate with males that have already received clutches of eggs (e.g., Ridley and Rechten, 1981;Marconato and Bisazza, 1986;Forsgren et al, 1996, but see Andrén and Kvarnemo, 2014). In one species, the striped darter Etheostoma virgatum, Porter et al (2002) suggest the males have evolved 'egg-like' spots to mimic the possession of eggs under their care, in order to attract matings.…”