. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. , P i •-*? .^. -. v Figure -1. Ltilrunciilui iiu/xnilicii choanocyte chamber, (a) Choano- cyte chamber. Note the flagellum (f), microvilli (v), and the amebocyte (a) that destroys the captured particles. Scale bar = 5 /^m (TEM). (b) Two enlarged choanocUes. Cell body, microvilli (v). and flagellum (f). Scale bar = ^m (TEM). No periflagellar sleeve is present in either picture. cysts are encircled by surrounding cells, and the sperm grow in number while decreasing in size (Fig. 1). The diameter of the cyst is 47 ± 13 ^m,
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. , P i •-*? .^. -. v Figure -1. Ltilrunciilui iiu/xnilicii choanocyte chamber, (a) Choano- cyte chamber. Note the flagellum (f), microvilli (v), and the amebocyte (a) that destroys the captured particles. Scale bar = 5 /^m (TEM). (b) Two enlarged choanocUes. Cell body, microvilli (v). and flagellum (f). Scale bar = ^m (TEM). No periflagellar sleeve is present in either picture. cysts are encircled by surrounding cells, and the sperm grow in number while decreasing in size (Fig. 1). The diameter of the cyst is 47 ± 13 ^m, and they are present in different developmental stages (Fig. 1). Oocytes develop in size by engulfing surrounding nurse cells (Fig. 2). Large oocytes (393 ± 91 nm) are fertilized internally and are incubated until they develop into mature parenchymella larvae (Fig. 3d). The embryos are bright orange to red in color. They are distributed throughout the mesohyl (never in the cortex) and are very distinct against the pale red color of the inner parts of L. magnified. The developing embryos are encircled with a layer of cells, some of which secrete a collageneous coat of fibrils around the embryo (Fig. 3b). The inner cells of the embryo are of several types (Fig. 3a-e). The fully ciliated larva is large and reaches up to 1200 pm (mean 868 ± 144 j/m). No free- swimming larva was observed during this study. Figure 4 depicts a choanocyte chamber. It is apparent that no periflagellar sleeve is present around the base of the choanocyte's flagellum. The chamber has a diameter of about 25 j/m and is constructed of 3-^m-wide choano- cytes. The discorhabd microscleres, which are typical of the Latrunculiidae, are found mostly at the dermal crust of the sponge (Fig. 5). In addition, the sponge contains some spongin fibers. The gross morphology of L. magnified is highly variable, and specimens collected in the different localities were within the variation found in any of the given local
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
