Kin Recognition in a Clonal Fish,Poecilia Formosa

Abstract

Relatedness strongly influences social behaviors in a wide variety of species. For most species, the highest typical degree of relatedness is between full siblings with 50% shared genes. However, this is poorly understood in species with unusually high relatedness between individuals: clonal organisms. Although there has been some investigation into clonal invertebrates and yeast, nothing is known about kin selection in clonal vertebrates. We show that a clonal fish, the Amazon molly (Poecilia formosa), can distinguish between different clonal lineages, associating with genetically identical, sister clones, and use multiple sensory modalities. Also, they scale their aggressive behaviors according to the relatedness to other females: they are more aggressive to non-related clones. Our results demonstrate that even in species with very small genetic differences between individuals, kin recognition can be adaptive. Their discriminatory abilities and regulation of costly behaviors provides a powerful example of natural selection in species with limited genetic diversity.

Female-female aggression in a sexual/unisexual species complex over resources

“…Indeed, there was no difference between unimodal (visual or chemical only) or bimodal (the combination of visual and chemical) cues. This was confirmed in a field based experiment, where in highly turbid environments, Amazon mollies depended on chemical cues more readily than in the laboratory, 1 where visual cues were more predominant (Makowicz et al 2016). Makowicz et al (2016) predicted that one of the adaptive values of this behavior was to regulate the aggressive behaviors found in this species.…”

“…Recent work has shown that Amazon mollies are able to recognize and prefer clonal sisters to non-sisters (Makowicz et al 2016). The existence of kin recognition in this species is interesting in and of itself, however, the study also showed that Amazon females could discriminate between clonal types using visual only and chemical only cues.…”

Social function of a variable lateral stripe in Xiphophorus hellerii?

“…Chemical information alone appears ineffective, although it is otherwise used widely in swordtails and other Poeciliids (Fisher & Rosenthal, ; McLennan & Ryan, ; Wong et al., ). We do not think that the method used here led to the lack of response, because in a different study using similar containers and investigating clonal recognition in the Amazon molly, females were able to recognize kin using all modalities investigated here (Makowicz et al., ). This strong role of visual communication is not a completely unexpected result, as visual displays are known to be important in swordtails, both in male contests and for acquiring mates.…”

“…Data were then normalized using √arc (sin) transformation. Any trials in which the female showed a side bias (more than 85% of time on one side; McCoy et al., ; Makowicz et al., ) were excluded from analysis. Eighteen trials were excluded due to side bias, but a binomial test indicated that side biases were distributed randomly between the two sides.…”

“…All trials were conducted in a clear 37.85‐L tank with all but the observer's side covered by white plastic boards to prevent visual distractions to the focal male. Using a variety of smaller prism‐shaped Plexiglas containers, we created treatments that limited information transmission between males (Makowicz, Tiedemann, Steele, & Schlupp, ). We did this to examine which sensory modalities might be involved in regulating color change of the lateral stripe.…”