Data from: Phenotypic plasticity drives the development of laterality in the scale-eating cichlid fish Perissodus microlepis
Data files
Nov 03, 2025 version files 13.81 KB
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Inter-individual_distance.csv
920 B
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Mandibular_asymmetry_of_wild-caught_fish_and_isolated-rearing_fish.csv
740 B
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PCA_of_the_lower_jawbone.csv
5.57 KB
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README.md
3.40 KB
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Swimming_distance_of_scale-eaters.csv
1.11 KB
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The_asymmetry_index_of_mandibular_height.csv
693 B
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The_number_of_attacks_in_10-min.csv
333 B
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The_number_of_attacks_in_the_first_minute.csv
313 B
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The_swimming_distance_of_prey.csv
727 B
Abstract
Phenotypic plasticity, in which traits change in response to environmental conditions, is closely related to predator–prey interactions and speciation. The scale-eating cichlid fish Perissodus microlepis exhibits marked left–right differences in predatory behaviour and mouth morphology. While phenotypic plasticity is hypothesized to contribute to the formation of laterality, direct evidence remains scarce. We examined how plasticity shapes laterality by analysing the predatory behaviour and mandibular changes under different foraging conditions: picking granulated feed (non-scale-eating) and tearing scales from prey fish. During the predation experiment, the number of attacks increased over time. Behavioural analysis revealed that the mean inter-individual distance from scale-eater to prey gradually decreased, whereas mean swimming activity increased. Morphological analysis of the mandible showed elongation of the dentary bone along the anterior–posterior axis in the scale-eating groups compared to the non-scale-eating group. Furthermore, mandible height was significantly greater on the dominant side, with the degree of asymmetry increasing with scale-eating experience. This strongly suggests that phenotypic plasticity contributes to the enhancement of laterality and promotes disruptive selection of lateral morphs. This study advances our understanding of the unique adaptation in P. microlepis and highlights the importance of feeding experience in shaping adaptive traits within the cichlid lineage.
Dataset DOI: 10.5061/dryad.q83bk3jv8
Description of the data and file structure
The scale-eaters used in our study were bred in our laboratory with the help of the World Freshwater Aquarium Aquatotto Gifu in Japan. We prepared three groups of specimens with different levels of scale-eating experience. The predation experiments were conducted daily for 127 days from the start, and predation was recorded every few days with a video camera; 32 videos of the Prey 1 group and 29 videos of the Prey 2 group were obtained. To detect the position of each scale-eating fish and prey fish in the tank, we fine-tuned the pre-trained neural network YOLO v3 on our dataset taken from the predation experiment. To assess the morphological features of the mouth of P. microlepis, we performed a geometric morphometric analysis on the lower jawbone.
File 1: Inter-individual_distance.csv
Description:
Relationship between the number of experimental days and inter-individual distance between scale-eating fish and prey fish.
File 2: Swimming_distance_of_scale-eaters.csv
Description:
Relationship between the number of experimental days and the swimming distance of scale-eaters. Swimming activity was positively correlated with the number of experimental days in both groups.
File 3: The_number_of_attacks_in_10-min.csv
Description:
Relationship between the number of experimental day s and the number of attacks in the experimental 10-min period.
File 4: The_number_of_attacks_in_the_first_minute.csv
Description:
Change over time in the number of attacks in the first minute of the experiment.
File 5: PCA_of_the_lower_jawbone.csv
Description:
Scatter plots of PC1 and PC2 from principal component analysis of the lower jawbone. In AorBorC column, "A" is Prey 1 group, "B" is Prey 2 group, and "C" is Non-scale-eating group. In Dominance, "D" is a dominant side jaw, and "N" is a non-dominant side jaw.
File 6: The_asymmetry_index_of_mandibular_height.csv
Description:
The asymmetry index of mandibular height in Prey 2 group, Prey 1 group, and the non-scale-eating group.
File 7: The_swimming_distance_of_prey.csv
Description:
Relationship between the number of experimental days and the swimming distance of prey fish.
File 8: Mandibular_asymmetry_of_wild-caught_fish_and_isolated-rearing_fish.csv
Description:
Comparison of mandibular asymmetry between wild-caught fish and isolated-rearing fish.
Variables
- Inter-individual distance: to determine changes in predation behavior with scale-eating experience, we took the coordinates during the first minute after the introduction of prey and calculated the inter-individual distance between them. The unit for inter-individual distance is pixels.
- Swimming distance: using optical flow, we calculated the swimming activity of scale-eating fish, defined as the total swimming distance of the fish in the movie. The unit for swimming distance is pixels.
- Number of attacks: we counted the number of attacks during a 10-minute period based on video data.
- Asymmetry index: we measured the length of the entire posterior dimension of each lower jaw.
The scale-eaters used in our study were bred in our laboratory with help of the World Freshwater Aquarium Aquatotto Gifu in Japan. We prepared three groups of specimens with different levels of scale-eating experience. The predation experiments were conducted daily for 127 days from the start, and predation was recorded every few days with a video camera; 32 videos of the Prey 1 group and 29 videos of the Prey 2 group were obtained. To detect the position of each scale-eating fish and prey fish in the tank, we fine-tuned the pre-trained neural network YOLO v3 on our dataset taken from the predation experiment. To assess the morphological features of the mouth of P. microlepis, we performed a geometric morphometric analysis on the lower jawbone.