Abstract
The first larval stage of Scyllarus posteli Forest, 1963, and Processa macrodactyla Holthuis, 1952, are described and illustrated from material reared in the laboratory. For both a diagnostic key for the identification of the first larval stage is provided.
For Mediterranean and adjacent Atlantic Scyllarus species have been described but this is the first larval stage of a Scyllarus to be identified with certainty. S. posteli belongs to the second scyllarid group larvae proposed by Sekiguchi (1987), which has four long plumose setae on the distal segment of the maxilla. Processa macrodactyla is characterized by presenting abdominal somite 3 without dorsal spine, four small marginal denticles behind pterygostomian spine, and antennal exopod at least 3/4 the length of antennal scale.