Recent studies have uncovered more details about the handedness trait in the Perissodus microlepis cichlid.
Being right-handed or left-handed isn't a trait reserved exclusively for humans. Animals like birds and great apes have this trait as well. as do the cichlid fish (Perissodus microlepis species).
Now, recent studies have uncovered more details about the trait in this species.
Endemic to Lake Tanganyika in Africa, the fish feeds exclusively on the scales of other fishes. There are two distinct morphological forms: one has its mouth parts twisted to the left, and the other has the mouth parts twisted to the right. A study by scientists from Nagoya University and University of Toyama discovered that the preference to attack the prey from the right or left side is an acquired trait.
A press release states that "naive juvenile P. microlepis with no prior scale-eating experience started attacking prey on both sides, but they gradually tended to attack the side that corresponded to the mouth opening direction during subsequent trials." This is reinforced by previous stomach content analysis which showed that young juvenile fish ate scales from both sides of the prey while the adults ate scales from just one side of the prey.
The findings of their research have been published in the Scientific Reports journal.
In a separate study, scientists from the University of Konstanz discovered that the "preference for one side in the animal’s feeding behaviour correlates with a corresponding asymmetry of the cerebral hemispheres as well as unequal gene expression in the different hemispheres."
"Our research helps us to understand handedness and hemispheric asymmetries better. We hope that our results also will contribute to further our understanding of handedness in humans", said lead author and biologist Dr Ralf Schneider.
The findings of the study have been published in the Genome Biology and Evolution journal.