Untangling the diversity and evolution of tentacles in scallops, oysters, and their relatives (Bivalvia: Pteriomorphia)

Autor(es)

Audino, Jorge A. ^[1] ; Serb, Jeanne M. ^[2] ; Marian, Jose Eduardo A. R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Zool, Rua Matao, Travessa 14, 101, BR-05508090 Sao Paulo, SP - Brazil

^[2] Iowa State Univ, Dept Ecol Evolut & Organismal Biol, 2200 Osborn Dr, Ames, IA 50011 - USA

• Tipo de documento: Artigo Científico
• Fonte: ORGANISMS DIVERSITY & EVOLUTION; v. 21, n. 1 JAN 2021.
• Citações Web of Science: 0

Resumo

Tentacles are fascinating, multifunctional organs found in many aquatic invertebrate groups. In bivalves, tentacles are morphologically diverse, performing protective and sensory roles in taxa from different ecological niches. Such diversity is particularly accentuated in Pteriomorphia, a clade comprising scallops, oysters, file clams, and relatives. However, little is known about the evolution of these organs and their role in bivalve radiation. To test hypotheses of convergent tentacular evolution and a possible association between tentacles and body orientation on the substrate, we first examined tentacle morphology in 108 preserved species representing 15 families across Pteriomorphia. Morphological descriptions of tentacle type (inner mantle fold tentacles, IFT; middle mantle fold tentacles, MFT) and position (marginal and submarginal) are provided, expanding the knowledge of less studied bivalve taxa. Then, we placed the morphological dataset under a molecular phylogenetic framework to estimate ancestral states. IFT had likely four independent origins, while MFT emerged twice independently. After being gained, tentacles have not been lost. In addition, evolution of MFT coincides with transitions in body position with the midsagittal plane parallel to the substrate in the clades of scallops (Pectinida) and oysters (Ostreida). Such a shift could be related to the increase of mantle exposure, favoring the emergence of serially repeated organs, such as tentacles. Altogether, our results support the convergent evolution of tentacles across different taxonomic levels, corroborating the plasticity of the molluscan body and the relevance of evolutionary convergences in the radiation of bivalves. (AU)

• Processo FAPESP: 17/01365-3 - Métodos filogenéticos comparativos e evolução da margem do manto: implicações para a diversificação morfológica e ecológica em Pteriomorphia (Mollusca, Bivalvia)
• Beneficiário: Jorge Alves Audino
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado