Mitsuto Aibara

1 Introduction Ensuring the survival of offspring by adapting reproductive strategies to the ecological niche is a pivotal factor contributing to the prosperity of the species. Reproductive strategies in organisms vary widely, from mammals that protect a small number of offspring through viviparity to species like some insects that release vast quantities of eggs.

1 Introduction Cichlids (family Cichlidae) are tropical freshwater fish that inhabit various regions spanning Central and South America to Africa, Madagascar, and India. The total number of cichlid species is estimated to be approximately 3000, representing approximately 10% of all teleost fish (Kocher 2004). Notably, approximately half of the extant cichlid species inhabit the East African Great Lakes, specifically Lake Tanganyika, Lake Malawi, and Lake Victoria (Salzburger et al.

Abstract Cichlids that have undergone adaptive radiation are genetically close but exhibit extreme ecological and morphological diversity, making them useful for understanding speciation mechanisms. Vomeronasal type 1 receptors (V1R) are highly conserved among teleost fish at the amino acid sequence level and believed to play a fundamental role in reproduction.