Taxonomic status of Tambja abdere and Tambja fusca based on morphological and molecular evidence, with comments on the phylogeny of the subfamily Nembrothinae (Nudibranchia, Polyceridae)

• Published in: Annales zoologici fennici 2006, Vol.43 (1), p.52-64
• Main Authors: Pola, Marta, Vallès, Yvonne, Cervera, J. Lucas, Medina, Mónica, Gosliner, Terrence M.
• Format: Article
• Language: English
• Subjects: Biological taxonomies; DNA; Evolution; Marine; Maximum parsimony; New species; Nudibranchia; Phylogenetics; Phylogeny; Polyceridae; Salivary glands; Tambja abdere; Tambja fusca; Taxa; Young animals
• ISSN: 0003-455X; 1797-2450

The use of morphological characters as the basis for species recognition and identification has permitted the development of a consistent taxonomy. However, limitations are evident when dealing with cryptic speciation or when intra-specific variability matches the total inter-species variation. Molecular techniques complement or enhance morphological inference by providing sets of data directly applicable to the taxonomic problem. Cases in which molecular techniques are particularly relevant are those involving larval or juvenile identification for which taxonomic characters are based on adult organisms and also those in which the original taxon description leads to uncertainty over the applicability of the species name. In this paper we report the use of mitochondrial DNA sequence data in a group of nudibranchs to exemplify the two cases mentioned above. The first issue is the longstanding debate on the taxonomic status of Tambja abdere and Tambja fusca, and the second issue is the identification of two juvenile specimens previously considered to represent two different undescribed species of the genus Tambja from the scarcely explored waters of Costa Rica. We also present a preliminary molecular phylogeny of the subfamily Nembrothinae.