Review: Fundamentals of Bivalve Anatomy and Gross Examination for the Diagnostician: Comparison of Tridacna Crocea, Mercenaria Mercenaria and Crassostrea Virginica
Barbara J. Sheppard1,2
Abstract
The Phylum Mollusca is large, diverse, and well-represented across our planet in all types of aquatic environments as well as having terrestrial members.1 The exotic shapes and colors of these animals have led to their incorporation into many display collections.2,3 They are indicator species in fragile, challenged, ecosystems, and continue to be an important food sources.3,4,5 The lack of familiarity with the anatomy and physiology of invertebrates within the Phylum Mollusca, and, more specifically the Class Bivalvia, can present a significant diagnostic challenge when investigating morbidity or mortality in bivalve submissions, collections, or producer stocks. The Tridacna crocea, Eastern Oyster (Crassostrea virginica), and Hard Clam (Mercenaria mercenaria), are three economically-important species demonstrating three different gross anatomic organization patterns including the shell designs. Their normal and most common pathologic appearances are compared to acquaint the investigator and diagnostician with different patterns that may be encountered.7,8,9 The comparisons and system descriptions, which are based upon evolutionary modifications, should facilitate the performance of a gross examination with identification of key structures needed for diagnostic assays and histopathology, and encourage an appreciation of differences in bivalve species.
Literature Cited
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