A review of the genus Narcissia Gray, 1840 (Echinodermata: Asteroidea: Ophidiasteridae)

Abstract

Abstract Since the taxonomic revision of the Ophidiasteridae by H.L. Clark (1921), in which 20 genera were recognized as valid, several new genera and species were included in this family, and the boundaries between some of them became largely arbitrary. This also applies to Narcissia Gray, 1840, whose morphology and taxonomy are still very poorly understood today. The main goals of this research were: review the taxonomy of the genus Narcissia, from morphological studies; redescribe N. trigonaria Sladen, 1889s. str.; characterize N. canariensis (d'Orbigny, 1839) and N. gracilis A.H. Clark, 1916, the two valid species most similar to N. trigonaria; review the validity of N. ahearnae Pawson, 2007 and N. trigonaria var. helenae Mortensen, 1933; review the validity of N. gracilis malpeloensis Downey, 1975. Altogether 370 specimens were analysed. All morphological structures of taxonomic importance have been illustrated, and, for the first time, the internal characters of this group were studied, from electron microscopy and microtomography. A new diagnosis for the genus Narcissia was constructed. Narcissia trigonaria was redescribed from a large specimen, from the type locality (Bahia, Brazil). Narcissia ahearnae is considered a valid species, and N. canariensis and N. trigonaria distinct entities. Narcissia trigonaria var. helenae is placed in the synonymy of N. trigonaria, and N. gracilis malpeloensis into the synonymy of N. gracilis. The dataset obtained in this work is by far the most complete acquired for the genus Narcissia.