# Genetic Variability Related Behavioral Plasticity in Pikeperch (Sander lucioperca L.) Fingerlings

## TL;DR

This study shows that pikeperch fingerlings' feeding behavior on pellets affects genetic diversity, with pellet-refusing individuals showing higher genetic variation.

## Contribution

The study reveals a novel link between pellet-feeding behavior and genetic diversity in pikeperch during domestication.

## Key findings

- Pellet-refusing pikeperch show higher genetic variation compared to pellet-consuming individuals.
- Cannibalistic pikeperch maintain genetic variability similar to the initial population.
- A marker under positive selection distinguishes pellet-consuming and pellet-refusing groups.

## Abstract

In addition to the traits that are directly influenced by humans, many other traits change as a result of the cultural environment during domestication. The ability to adapt to a new environment varies greatly between individuals and depends on genetic diversity. In the intensive rearing of fish, pelleted feed is used. For piscivorous species such as pikeperch, this deviates significantly from their natural diet and influences the survival of their larvae. In our study, we investigated genetic variation among individuals consuming pellets, those refusing to eat pellets, and those adopting an alternative strategy (cannibalism). Our results show that individuals that do not consume pellets have higher genetic variation than those that do, and that the two groups are genetically distinguishable, as confirmed by a marker under positive selection. These results suggest that pellet habituation acts as an uncontrolled selective force during domestication, influencing the genetic variability of domesticated stocks. Cannibal individuals exhibited variability comparable to that observed in the initial population, and they originated from the same proportions of the two genetic clusters that define the other two groups. This indicates that the emergence of the trait is independent of the ability to consume pellets.

Background: The relationship between genetic diversity and fitness is well understood, but few studies have investigated how behavior influences genetic diversity, or vice versa. We investigated the relationship between feeding behavior (on a pelleted diet) and genetic diversity in pikeperch, a piscivorous species. Methods: A total of 135 juvenile pikeperch from the same stock were grouped into three behavioral groups: pellet consuming, pellet refusing, and cannibalistic. Eighteen microsatellite markers were used to characterize the genetic diversity and structure of individuals. Results: The juveniles were classified into two genetic clusters: one dominated by pellet-consuming individuals and the other by pellet-refusing individuals containing equal proportions of cannibal individuals. Three of the microsatellite markers were under selection, but only one showed significant genetic segregation between the groups. For this marker, the pellet consumption was associated with low fragment length. Individual multilocus heterozygosity was significantly higher in the pellet-refusing group. Conclusions: These results suggest that pellet consumption acts as an uncontrolled selective force during domestication, influencing the genetic variability of domesticated populations. The ability to habituate to pellets has a significant genetic basis. Cannibalism does not affect genetic variability, and the emergence of the trait is independent of the propensity to consume pellets.