Description of the first-stage juvenile of Aegla jacutinga Marçal & Teixeira in Marçal, Páez, Souza-Shibatta, Sofia & Teixeira, 2020 (Decapoda: Anomura: Aeglidae) from southeastern Brazil

Abstract The morphologies of only 10 of the 93 described species of Aegla Leach, 1820 are known. We describe and illustrate the external morphology of newly-hatched, first-stage juveniles of Aegla jacutinga Marçal & Teixeira in Marçal, Páez, Souza-Shibatta, Sofia & Teixeira, 2020 using light microscopy and scanning electron microscopy (SEM) comparing them with the same stage in other congeners and providing diagnostic characters. Aegla is morphologically a conservative genus, which creates many problems in the identification of its many cryptic species. It thus becomes necessary to refine the taxonomic characters used in the taxonomy of the group by providing a new sets of morphological characters to be analyzed.