Comparative and functional anatomy of the mantle margin in ark clams and their relatives (Bivalvia: Arcoidea) supports association between morphology and life habits

Autor(es)

Audino, J. A. ^[1] ; Marian, J. E. 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

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF ZOOLOGY; v. 305, n. 3, p. 149-162, JUL 2018.
• Citações Web of Science: 2

Resumo

Evaluating the association between ecology and the evolution of morphological traits is a central question of macroevolutionary studies. The Arcoidea comprises several lineages of epibyssate (epifaunal) and endobyssate (semi-infaunal or infaunal) bivalves, which makes them a suitable model for analyzing the implications of similar life habits on phenotype. Also, the families currently assigned to the clade (Arcidae, Cucullaeidae, Glycymerididae, and Noetiidae) exhibit great variation in the mantle margin, a region responsible for interacting with the surrounding environment and provided with sensory structures (e.g., photoreceptor organs). Consequently, this anatomical region includes traits relevant for testing hypotheses of morphological attributes associated with lifestyles. For this purpose, we investigated the detailed anatomy of the mantle margin of three arcoidean species (i.e., Arca imbricata, Barbatia candida, and Arcopsis adamsi) applying integrative microscopy, and complemented the study with basic morphological analysis of 27 species obtained in museum collections. Secretory cells, muscle fibers and sensory organs are described in detail, including sensory ciliated cells of the inner mantle fold, reported for the first time. Our results corroborate a very reduced to absent middle fold in arcoideans, with transfer of sensory functions to the first outer and inner folds. Moreover, our data indicates association of some pallial characters with life habits, i.e., presence of pallial pigmentation and photoreceptor organs in epibyssates, and development of an enlarged pallial curtain in endobyssates, which should stimulate further investigations on these potentially adaptive morphological features. (AU)

• Processo FAPESP: 15/09519-4 - Evolução e anatomia funcional da margem palial em Pteriomorphia (Mollusca, Bivalvia)
• Beneficiário: Jorge Alves Audino
• Modalidade de apoio: Bolsas no Brasil - Doutorado