Vol. 154, No. 1 February, 1978 THE BIOLOGICAL BULLETIN PUBLISHED BY THE MARINE BIOLOGICAL LABORATORY STUDIES OX FUNCTIONAL MORPHOLOGY IN THE DIGESTIVE SYSTEM OF OREASTER RETICCLATL'S (L.) (ASTEROIDEA) Reference: Biol. Bull., 154: 1-14. (February, 1978) JOHN MAXWELL ANDERSON Division of Biological Sciences, Cornell University, Ithaca, New York 14853 Orcastcr reticulatus (Fig. 1 ) is a large, conspicuous, and easily-recognized sea-star, abundant within its broad geographical range and probably of considerable ecological significance where it occurs. Curiously, however, the number of pub-lished papers dealing with aspects of the basic biology of this species is small. A brief note by Thomas (1960) describes its feeding habits; another, almost as brief, by Matthews and Lima-Verde (1968) suggests an ecological relationship between Orcastcr and two species of Panulints on the fishing-banks of Northeastern Brazil. The entire literature dealing with the internal anatomy of O. reticulatus appears to consist of a four-page paper with three plates by Tennent and Keiller (1911 ) and a brief abstract by Anderson (1967) reporting preliminary observations on the digestive system. Some special features of the internal anatomy of Culcita, a genus assigned to the Family Oreasteridae, were described and figured (rather sketchily) by Miiller and Troschel (1842). whose drawing was reproduced by such later authors as Luclwig and Hamann (1899) ; but beyond this, published information on Greasier and its relatives is scanty. The purpose of the present paper is to describe, in greater detail than that provided in previous accounts, the general morphology of the digestive system as a whole, noting particularly some interesting-features of the pyloric stomach and related structures. This is intended as a con-tribution toward a broadly comparative survey of digestive systems among asteroids. Such a survey has never been undertaken ; a step in this direction is provided by Anderson (1966), and a further contribution appears in Jangoux and van Impe (1971), but available data are still inadequate to permit comparisons in detail among representatives of many different families of sea-stars. Further, an attempt will be made to draw together published and unpublished descriptions of feeding-behavior in Orcastcr. and to correlate these with structural features of the digestive system. The results of histological studies on this system are to be published in a subsequent paper. Paraphrasing a statement concerning Orcastcr that he had published in 1902, 1 Copyright 1978, by the Marine Biological Laboratory Library of Congress Card No. A38-518
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