Larval development of the stygobitic shrimp Creaseria morleyi (Creaser, 1936) (Decapoda: Caridea: Palaemonidae) from the Yucatán Peninsula, Mexico

Abstract

Abstract Although the larval development of epigean palaemonid shrimps has been studied extensively, only a few investigations deal with stygobitic species. We present the larval development of the cave-adapted Creaseria morleyi (Creaser, 1936) from anchialine caves in the Tulum area, Quintana Roo, Yucatán Peninsula, Mexico. Through the discovery of a series of larvae at different stages of development, we constructed a sequence extending through the juvenile stage. The larvae (41) were captured in plankton tows above the halocline at depths ranging between 11 and 15 m during eight surveys conducted between 2013 and 2016. Six larval stages and the first juvenile were identified; however, it is clear from the gradual modification of structures and appendages that more stages exist. The first larvae have a large quantity of vitellum and do not feed, since they have only rudimentary, and possibly non-functional, mouthparts. In the sixth stage and the juvenile, when the stages have no vitellum left, the mouthparts, chelae, and pleopods develop entirely. A comparison with other palaemonid shrimps suggests that C. morleyi has a greater affinity with those palaemonid species possessing extended larval development as is seen in species of MacrobrachiumSpence Bate, 1868.