Double Mutualism Involving Melocactus (cactaceae) and Lizards in the Brazilian Caatinga: Another Isolated Case or is It an Established Interaction?

This work discusses a fascinating ecological relationship, in which the lizard Tropidurus cocorobensis and the cactus Melocactus violaceus engage in a double mutualism. In this interaction, observed in a Caatinga, a dry tropical forest in Northeastern Brazil, T. cocorobensis feed on the nectar and pollen of M. violaceus, transferring the grains to the stigmas of another flower, acting as a potential pollinator. Additionally, the lizards consume fruits of M. violaceus, helping to disperse the seeds. The concentrated nectar of M. violaceus attracts lizards, and the morphological compatibility between the small pink flowers and the size of T. cocorobensis is important to this double mutualism. The findings mentioned here highlight the importance of Tropidurus lizards in the reproductive success of Melocactus species and provide insights into the coevolution of these species in a seasonal and resource-scarce environment, like the Caatinga.