Nature Communications, Published online: 31 March 2026; doi:10.1038/s41467-026-71179-4The origins of brood parasitism outside of birds remain poorly understood. In cuckoo catfish, this study finds that ancestral large eggs and rapid development likely enabled the emergence of brood parasitism, and its success enhanced by evolving egg mimicry, small clutches, and embryonic dentition.

Scientific Reports - Alternative social and reproductive niches linked to intra-sexual color variation in a facultatively protogynous North American annual killifish, Millerichthys robustus