The peristomial membrane of regular sea‐urchins: Functional morphology of the epidermis and coelomic lining inParacentrotus lividus(Lamarck)

Abstract

The functional organization of both the epidermis and the coelomic lining of the peristomial membrane in the regular seaurchin Paracentrotus lividus is described and correlated with the extreme deformability of the peristomial membrane and with the «mutability» of its related dermis. The epidermis consists of a monolayer of columnar supporting cells mixed with ciliated sensory cells, the wide interspaces between these epithelial cells being occupied apically by a variety of cell types and basally by a conspicuous basiepithelial nerve plexus. The coelomic lining is a peripharyngeal coelomic epithelium consisting of apical monociliated peritoneocytes and subapical myocytes, and has an associated basiepithelial nerve plexus. Although the basic morphology of these epithelia is similar to that of corresponding tissues in other echinoderms, they both have significant structural adaptations and display the histological pattern of typical transitional epithelia, which enables them to match the wide range of deformations shown by the peristomial membrane in vivo. Histofluorescence techniques were employed to explore the innervation of the outer epidermis and the inner coelomic lining.

Description on anatomy and histology of Echinometra mathaei (Echinoidea: Camarodonta: Echinometidae), the Persian Gulf sea urchin

“…The mouth is basically a large hole in the center of the oral surface of the test, surrounded by a flexible membrane, Peristome. The Peristome is an important part of the lantern in regular echinoids (Bonasoro, Candia & Wilkie 1995).Our observations were in consistent with other echinoids like Paracentrotus lividus in which the teeth and their peripheral layer approximately were similar to E. mathaei (Bonasoro et al 1995). E. mathaei like other species of the sea urchins has a specialized jaw structure to permit them to feed effectively on algae.…”

Production, Characterization and Biocompatibility of Marine Collagen Matrices from an Alternative and Sustainable Source: The Sea Urchin Paracentrotus lividus

“…The collagenous meshwork is the most significant component in terms of both structure and mechanical properties [10,11]. …”

“…The PM mainly consists of a thick ossicle-reinforced dermal layer externally covered by an epidermis and internally by a coelomic epithelium. The collagenous meshwork is the most significant component in terms of both structure and mechanical properties [ 10 , 11 ].…”

Functional morphology of the compass-rotular ligament of Echinus esculentus (Echinodermata: Echinoida): a non-mutable collagenous component of Aristotle’s lantern

“…Bachmann and Goldschmid 1978;Heinzeller and Welsch 1994;Bonasoro et al 1995;Candia Carnevali et al 1995) and of coelomic epithelia in general, including mammalian mesothelia (Welsch 1995). The last mentioned cells synthesise 'lamellar bodies' consisting of concentric arrangements of lipid bilayers, which after extrusion into the peritoneal cavity, form multivesicular structures or expand into a variety of vesicles with electron-lucent contents (Dobbie and Anderson 1996).…”