A new species of Acteon (Opisthobranchia: Acteonidae) from Northeast Brazil

A new species of Acteon Montfort 1810, Acteon mirim sp. nov., from Canopus Bank, state of Ceará, Brazil is described based on shell morphology. The new species is compared with other species of the genus reported from Brazil. It differs from other Brazilian species in having a whitish color with dark orange-brown spiral bands and a shell surface covered with small spiral grooves, regularly rectangular.

A special thanks to José and Marcus Coltro (São Paulo) for donating the specimens studied. Thanks are due as well to Antonio S. Vanin and Carlos Henckes for photographs of Holotype; to Bill Fenzan (USA), Paulino de Souza, Luiz. R. L. Simone (MZSP) and two anonymous reviewers for important comments and help in improving the language in the manuscript; to Lara Guimarães, Laboratório de Microscopia Eletrônica, MZSP, for helping with SEM examination of the specimens. This project is supported by Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP proc. #10/11253-9)