Journal article

Publication year: 2009

Pages: 459-468

Journal: Journal of Morphology

Volume number: 270

Issue number: 4

ISSN: 0362-2525

eISSN: 1097-4687

DOI Link: https://doi.org/10.1002/jmor.10701

Publisher: Wiley

Abstract: 
The pyriform appendage, an organ only found in nautiloid cephalopods was investigated with histological, histochemical and ultrastructural methods in order to characterize the anatomical and the cytological structure of this organ. The pyriform appendage is situated within the genital septum and lies in close contact with the ventricle. of the heart. The proximal side ends blindly near the gonad whereas the distal side is developed into a duct. The duct was observed to open into the mantle cavity in juvenile and adult Nautilus pompilius of both sexes. Injections of India ink in the heart demonstrate that the organ is supplied with hemolymph from an artery that extends from the heart. The pyriform. appendage is a hollow organ consisting mainly of glandular tissue. The lumen is covered with a columnar epithelium, the tunica mucosa, consisting of only one cell type containing vacuoles with different inclusions. Underneath the tunica mucosa is the tunica muscularis, which is embedded in connective tissue and folded, enlarging the internal surface. A cuboidal tunica serosa surrounds this organ. The vacuoles and the secretory products contain neutral mucopolysaccharides, glycoproteins and glycolipids. Acid phosphatase and serotonin were localized in the tunica mucosa. Acetylcholinesterase, catecholamines and the tetrapeptide FMRFamide were demonstrated within the nerve endings of the tunica muscularis indicating a dual "cholinergic-anunergic" neuroregulation, possibly modulated by FMRFamide. These findings suggest that the pyriform appendage is not a rudimentary organ but instead has distinct biological functions in nautiloid cephalopods, possibly in intraspecific communication. T. Morphol. 270:459-468, 2009. (C) 2009 Wiley-Liss, Inc.

Harvard Citation style: Spintzik, J., Springer, J. and Westermann, B. (2009) Morphological and Histological Organization of the Pyriform Appendage of the Tetrabranchiate Nautilus pompilius (Cephalopoda, Mollusca), Journal of Morphology, 270(4), pp. 459-468. https://doi.org/10.1002/jmor.10701

APA Citation style: Spintzik, J., Springer, J., & Westermann, B. (2009). Morphological and Histological Organization of the Pyriform Appendage of the Tetrabranchiate Nautilus pompilius (Cephalopoda, Mollusca). Journal of Morphology. 270(4), 459-468. https://doi.org/10.1002/jmor.10701