Rosette glands in the gills of the grass shrimp, Palaemonetes pugio. I. Comparative morphology, cyclical activity, and innervation

Abstract

Two types of exocrine rosette glands (called type A and type B), located in the gill axes of the grass shrimp Palaemonetes pugio, are described. The type A glands are embedded within the longitudinal median septum of the gill axes, whereas the type B glands typically project into the efferent hemolymph channels of the gill axes. Although both glands have certain common characteristics (i.e., a variable number of radially arranged secretory cells, a central intercalary cell, and a canal cell that forms the cuticular ductule leading to the branchial surface), they differ in the following respects. The type B gland is innervated, but the type A gland is not; axonal processes, containing both granular (ca. 900-1300 Å) and agranular (ca. 450-640 Å) vesicles, occur at a juncture between adjacent secretory cells and the central cell of the type B gland. The secretory cells of type A and type B glands differ in their synthetic potential and membrane specializations. These differences are more pronounced in well-developed, mature glands, most frequently encountered in larger (24-28 mm, total length) grass shrimp, than in the underdeveloped, immature glands that are most abundant in smaller (14-18 mm, total length) grass shrimp. Thus, in mature glands, the secretory cells of the type A rosette glands are characterized by extensive RER, abundant Golgi, and numerous secretory granules, whereas the secretory cells of the type B gland are characterized by extensively infolded and interdigitated basal plasmalemmas and by the presence of numerous mitochondria. In general, both types of glands exhibit increased secretory activity soon after ecdysis. The central and canal cells in both glands seem to have a role in the modification of the secreted materials. The possible functions assigned to the type A gland and the type B gland include phenol-oxidase secretion and osmoregulation, respectively.

A pair of rosette glands in the embryo and zoeal larva of an estuarine crab Sesarma haematocheir, and classification of the tegumental glands in the embryos of other crabs

“…The grass shrimp Palaemonetes pugio possesses two types of rosette gland: types A and B (Doughtie and Rao, 1982). The morphology of the type A gland in this shrimp is very similar to the type I gland described in Sesarma haematocheir embryos (Fig.…”

“…The central cell of other decapod crustaceans is bilobed; one lobe (central lobe) constitutes the central part of the gland, and another (peripheral lobe) is arranged in the same manner as the secretory cells (e.g., see fig. 1 in Doughtie and Rao, 1982). But the central cell of S. haematocheir is clearly separated from the b cell, and constitutes only the central lobe (Fig.…”

“…Tegumental glands derived from epidermal cells have been observed in a variety of tissues of the adult specimens of other decapod crustaceans (Herrick, 1895;Yonge, 1937;Doughtie and Rao, 1982;Johnson and Talbot, 1987;Alexander, 1989). The grass shrimp Palaemonetes pugio possesses two types of rosette gland: types A and B (Doughtie and Rao, 1982).…”

“…It is commonly characterized by three features: 1) radially arranged secretory cells; 2) a central cell at the center of the gland; and 3) a canal cell forming a duct (Herrick, 1895;Yonge, 1932;Gorvett, 1946;Felgenhauer, 1992;Talbot and Demers, 1993). The rosette glands are found in the exopodite of the pleopod of the female lobster Homarus americanus (Herrick, 1895;Johnson and Talbot, 1987), in the endopodite of the female lobster Homarus vulgaris (Yonge, 1937), in the gills of adult specimens of the grass shrimp, Palaemonetes pugio (Doughtie and Rao, 1982), and in the paragnaths of the shrimp Palaemon serratus (Alexander, 1989). Doughtie and Rao (1982) discriminated between two types of rosette glands (A and B) in the gill axis of the grass shrimp Palaemonetes pugio.…”

“…The rosette glands are found in the exopodite of the pleopod of the female lobster Homarus americanus (Herrick, 1895;Johnson and Talbot, 1987), in the endopodite of the female lobster Homarus vulgaris (Yonge, 1937), in the gills of adult specimens of the grass shrimp, Palaemonetes pugio (Doughtie and Rao, 1982), and in the paragnaths of the shrimp Palaemon serratus (Alexander, 1989). Doughtie and Rao (1982) discriminated between two types of rosette glands (A and B) in the gill axis of the grass shrimp Palaemonetes pugio. Type A is characterized by numerous secretory granules, rough endoplasmic reticulum, and Golgi bodies; type B is characterized by an infolded plasma membrane.…”