Anna L. Mikhlina, Ekaterina D. Nikitenko, Elena V. Vortsepneva
{"title":"Not all heroes wear shells: New data on the spicules' morphology in acochlidimorph mollusc","authors":"Anna L. Mikhlina, Ekaterina D. Nikitenko, Elena V. Vortsepneva","doi":"10.1111/azo.12517","DOIUrl":null,"url":null,"abstract":"Calcareous skeletal structures are common among different invertebrate groups, including Porifera, Cnidaria, Platyhelminthes, Mollusca, and Echinodermata. They appear externally as shells, plates, or scales, or internally as subepidermal spicules. Although typically formed outside of the cells, in one class of gastropod molluscs, the Heterobranchia, subepidermal and intracellular spicules are found—a rare case, at least for the molluscs. This type of spicules is present in several phylogenetically distant groups of heterobranch molluscs (Rhodopemorpha, Acochlidimorpha, and Nudibranchia), each different in terms of morphology and autecology. This raises questions about the origin and homology of subepidermal spicules in heterobranch molluscs. To answer these questions, understanding the process of spicule formation is crucial. This is impeded by insufficient data on the fine structure of the subepidermal spicules and adjacent epithelia. To address this problem, we carried out a comprehensive morphological study of subepidermal spicules and the body wall in one species of Acochlidimorpha. We revealed variations in the cellular composition of the epidermis, musculature organization, and spicules' arrangement, which most likely reflect the different functional roles of the spicule complex within Heterobranchia representatives. However, the obtained data are insufficient to answer the question of the origin of spicules and their homology within Heterobranchia.","PeriodicalId":50945,"journal":{"name":"Acta Zoologica","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Zoologica","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1111/azo.12517","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ANATOMY & MORPHOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Calcareous skeletal structures are common among different invertebrate groups, including Porifera, Cnidaria, Platyhelminthes, Mollusca, and Echinodermata. They appear externally as shells, plates, or scales, or internally as subepidermal spicules. Although typically formed outside of the cells, in one class of gastropod molluscs, the Heterobranchia, subepidermal and intracellular spicules are found—a rare case, at least for the molluscs. This type of spicules is present in several phylogenetically distant groups of heterobranch molluscs (Rhodopemorpha, Acochlidimorpha, and Nudibranchia), each different in terms of morphology and autecology. This raises questions about the origin and homology of subepidermal spicules in heterobranch molluscs. To answer these questions, understanding the process of spicule formation is crucial. This is impeded by insufficient data on the fine structure of the subepidermal spicules and adjacent epithelia. To address this problem, we carried out a comprehensive morphological study of subepidermal spicules and the body wall in one species of Acochlidimorpha. We revealed variations in the cellular composition of the epidermis, musculature organization, and spicules' arrangement, which most likely reflect the different functional roles of the spicule complex within Heterobranchia representatives. However, the obtained data are insufficient to answer the question of the origin of spicules and their homology within Heterobranchia.
期刊介绍:
Published regularly since 1920, Acta Zoologica has retained its position as one of the world''s leading journals in the field of animal organization, development, structure and function. Each issue publishes original research of interest to zoologists and physiologists worldwide, in the field of animal structure (from the cellular to the organismic level) and development with emphasis on functional, comparative and phylogenetic aspects. Occasional review articles are also published, as well as book reviews.