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Electron and light microscopic study of various glands and the secretions released into the environment by the turbellarian Urastoma cyprinae
Author(s) -
Bataller Erick E.,
Boghen Andrew D.,
Burt Michael D.B.
Publication year - 2003
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.10148
Subject(s) - biology , mucus , viral tegument , gill , epidermis (zoology) , anatomy , oligochaeta (plant) , parenchyma , ultrastructure , secretion , exocrine gland , microbiology and biotechnology , zoology , ecology , fish <actinopterygii> , endocrinology , botany , virology , fishery
The turbellarian Urastoma cyprinae (Graff) occurs on the gills of various bivalve species including the mussel Mytilus galloprovinciallis , where it is known to cause serious damage. More recently, it has been shown that the worms are strongly attracted to the gill of the American oyster ( Crassostrea virginica ) and are capable of inducing changes to the composition of proteolytic enzymes of the host mucus. Such changes may be attributable to secretory products released by the worms. Mucous glands (11–18 μm in diameter) produce minute spherules (0.7–0.9 μm in diameter) tightly bound together. The glands occupy ∼20% of the body volume and are the most voluminous secretory organs in the worm. The smaller rhabdoid glands are unevenly distributed throughout the peripheral parenchyma and contain secretory granules of 0.35–1.2 μm in diameter. The latter occur most prominently along the distal margins of the epidermis. The frontal pole of U. cyprinae consists of a complex assembly of mucous and rhabdoid gland cells as well as other glandular structures. Collectively, these bodies release their contents to the outside via narrow gland necks. The overall organization is consistent with the frontal gland previously described for other free‐living turbellarians, including other rhabdocoels. A variety of secretory products, displaying variations in staining properties, have likewise been identified in association with the body wall from other regions of the worm. This work attempts to gain a better appreciation of the secretory structures associated with the worm tegument, focusing primarily on the widespread mucous and rhabdoid glands. The secretions play a role in host‐parasite interactions. J. Morphol. 258:307–316, 2003. © 2003 Wiley‐Liss, Inc.