the reading question

The Fitness Benefits of Kin-Biased Behavior in Salmon

The author’s used prior studies on kin-biased behavior in territorial animals to describe fitness benefits in salmon. Increased growth rates of subordinate fish result in fitness gains for salmon due to increased longevity and a shorter life span. As a result of expanded feeding by subordinate kin, salmon kin exchanged food.

The Experimental Setup

The authors used wild juvenile Atlantic salmon and varied the spatial and temporal location of food patches to determine the following. The authors needed to know how likely it was for dominant fish in pairs to share food with kin rather than non-kin in the presence of high-quality feeding patches. Second, in the absence of the dominant individual, the authors wanted to know the sustainability of kin-based intimidation from dominant to subordinate.

The Methodology

Regarding experimental animals, the authors harvested the eggs and milt from adult salmon and produced kin groups. The authors fertilized eggs from one female with milt from one male to produce a family. Using the FRS Almond bank laboratory, the authors performed an experiment that included pairing juvenile salmon and releasing them into each test arena. After introducing the fish, the authors started to observe the dominance status of fish.

Results

Results show that the pairing of subordinate salmon with satiated dominant kin resulted in the consumption of a greater share of food than when paired with non-kin. Second, when the authors removed a half of the dominant fish from pairs of salmon, there was an increase in the feeding activity by subordinate fish with dominant kin than those that were previously paired with dominant non-kin.

Conclusion

In conclusion, the findings show that close association of subordinate fish with dominant kin and increased sharing of territory may result in them gaining foraging advantages. Also, subordinate fish may benefit from the reduction in the duration for food acquisition. According to the authors, intimidation influences the way animals use resources. Moderation of tolerance helps animals to accrue fitness benefits.