Genetic mating patterns studied in pools with manipulated nest site availability in two populations of Pomatoschistus minutus.
Pomatoschistus minutus show paternal care in a resource defence mating system. We investigated the effect of nest-site availability on parasitic spawning. Each experimental pool contained four potentially nest-building males, four females and nests-sites in shortage (2) or excess (6). Both treatments were conducted in two populations; one with natural nest-sites in excess, one with a nest-site shortage. Microsatellite-DNA revealed that all nest-holders had fertilized most of the eggs they tended. Yet, 35% of the nests contained eggs fertilized by another male and 14.4% of the males had performed parasitic spawning. There was no site or treatment effect. Several females spawned in two nests, which coincided with parasitic spawnings, suggesting a cost to the nest-holder in terms of lost mating success. Nest-holders with and without eggs and non-nesting males all spawned parasitically, generating a significantly lower opportunity for sexual selection compared to if there had been no parasitic spawning.
Singer
A
A
Department of Zoology, Stockholm University, Stockholm, Sweden.
Kvarnemo
C
C
Lindström
K
K
Svensson
O
O
D000818:Animals; D003163:Competitive Behavior; D004777:Environment; D005260:Female; D005306:Fertilization; D008297:Male; D008954:Models, Biological; D009425:Nesting Behavior; D010473:Perciformes / Q000235:genetics / Q000502:physiology*; D012641:Selection, Genetic; D012726:Sexual Behavior, Animal