Zoological Studies 57: 45 (2018) doi:10.6620/ZS.2018.57-45 Open Access Neotype Designation for the Marine Flatworm, Acanthozoon alderi (Polycladida: Cotylea: Pseudocerotidae), from India with Comments on the Taxonomical Status of the Genus Sudhanshu Dixit1, Verónica N. Bulnes2,*, and Chelladurai Raghunathan3 1Centre for Marine Living Resources and Ecology, Kochi, India. E-mail:
[email protected] 2Laboratorio de Zoología de Invertebrados I. INBIOSUR-CONICET-UNS. San Juan 670. 8000 Bahía Blanca. Buenos Aires. Argentina 3Zoological Survey of India, M - Block, Alipore, Kolkata, India. E-mail:
[email protected] (Received 16 April 2018; Accepted 16 August 2018; Published 27 September 2018; Communicated by Benny K.K. Chan) Citation: Dixit S, Bulnes VN, Raghunathan C. 2018. Neotype designation for the marine flatworm, Acanthozoon alderi (Polycladida: Cotylea: Pseudocerotidae), from India with comments on the taxonomical status of the genus. Zool Stud 57:45. doi:10.6620/ZS.2018.57- 45. Sudhanshu Dixit, Verónica N. Bulnes, and Chelladurai Raghunathan (2018) Acanthozoon alderi is an ovoid, medium-sized pseudocerotid. Body margin ruffled; pseudotentacles black and pointed, with white tips. Dorsal surface covered with papillae, except for the cerebral region. Background colour light brown, with marbled blackish pattern, middorsal black band with white blotches; black submarginal band and marginal white rim. This species was described from Borneo; however, no type specimen was designated or deposited in any museum by the author. Many nomenclature problems and misidentification have been encountered with this species (it has been identified as Acanthozoon sp. in many instances). Thus, it is necessary to designate a neotype to solve the problems of doubtful and confusing identities and maintain nomenclature stability.