Male Cardinalfish Use Color to Hide Their Eggs
Author Information
Author(s): Ishihara Hikaru, Kanda Shinji
Primary Institution: Atmosphere and Ocean Research Institute, The University of Tokyo
Hypothesis
The whitish coloration of the lower jaw in male cardinalfish serves to maintain optimal camouflage during mouthbrooding.
Conclusion
Male spotnape cardinalfish have a whitish lower jaw that conceals the coloration of eggs during mouthbrooding, which may help reduce predation risk.
Supporting Evidence
- Male cardinalfish exhibit a male-specific whitish lower jaw that reduces the visibility of eggs.
- The whitish lower jaw is induced by androgens during the breeding season.
- Iridophores in the lower jaw contribute to the male-specific coloration.
- Statistical analysis showed significant differences in transparency between male and female lower jaws.
- Artificially implanted eggs in male mouths did not reflect their coloration, unlike in females.
Takeaway
Male cardinalfish have a special white color in their lower jaw that helps them hide their eggs in their mouth so predators can't see them.
Methodology
The study involved observing the morphology of male and female cardinalfish, artificial implantation of eggs, and histological analysis to identify iridophores.
Limitations
The study could not directly prove that the whitish coloration increases fitness in terms of survival against predators.
Participant Demographics
The study focused on male and female spotnape cardinalfish (Ostorhinchus notatus) and other related species.
Statistical Information
P-Value
p<0.01
Statistical Significance
p<0.01
Digital Object Identifier (DOI)
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