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Intestinal Ultrastructure of Nerita picea (Mollusca: Gastropoda), an Intertidal Marine Snail of Hawaii
Author(s) -
Pfeiffer Carl J.
Publication year - 1992
Publication title -
acta zoologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.414
H-Index - 37
eISSN - 1463-6395
pISSN - 0001-7272
DOI - 10.1111/j.1463-6395.1992.tb00947.x
Subject(s) - biology , ultrastructure , enteroendocrine cell , gastropoda , snail , secretion , microbiology and biotechnology , anatomy , endocrine system , biochemistry , zoology , ecology , hormone
Abstract The neritid snail Nerita picea is a marine prosobranch mollusc which resides high in the intertidal zone on the Hawaiian Islands. Since other studies have shown considerable variations in molluscan gut histology and the relatively few recent ultrastructural reports have revealed novel cellular structures in the molluscan gastrointestinal tract, this investigation was directed toward ultrastructural clarification of the neritid intestine. Seven principal cell types constituted the intestinal architecture, including absorptive cells, zymogen cells, neural and endocrine cells, myocytes, pigment and gland cells. The intestinal epithelium was composed mainly of tall ciliated (9 plus 2 complement of microtubules) columnar absorptive cells which also possessed microvilli, extensive deposits of non‐membrane‐bound lipid‐like droplets, and large reservoirs of glycogen‐like granules. Less frequent, columnar zymogen cells contained numerous large zymogen secretory granules and possessed microvilli but not cilia. Small endocrine‐like cells with secretory granules were observed basolaterally between some absorptive cells, resembling mammalian gut endocrine cells. Nerve fibers were prevalent in close association with the epithelial cells. A thin layer of non‐striated muscle was present, as well as a serosally located gland composed of storage cells with a granular matrix and large granules.