. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PVD DVD. FIGURE 1. a. Diagrammatic representation of the male reproductive system of A. symnista. b. Dia- grammatic representation of the male reproductive system of E. asiatica. T = testis; PVD = proximal vas deferens; DVD = distal vas deferens; A = ampulla. Arrangement of spermatophore inside VD The mature vesiculate spermatozoa, as released from the testes, are clumped in the anterior-most part of the proximal VD (Figs. 2, 3). This sperm mass is ensheathed in a thin wall formed by the condensation of secretory material pr
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PVD DVD. FIGURE 1. a. Diagrammatic representation of the male reproductive system of A. symnista. b. Dia- grammatic representation of the male reproductive system of E. asiatica. T = testis; PVD = proximal vas deferens; DVD = distal vas deferens; A = ampulla. Arrangement of spermatophore inside VD The mature vesiculate spermatozoa, as released from the testes, are clumped in the anterior-most part of the proximal VD (Figs. 2, 3). This sperm mass is ensheathed in a thin wall formed by the condensation of secretory material probably emanating from the hyperactive epithelial cells (Fig. 4). This walled sperm mass passes into the enlarged distal portion of the VD. The completed spennatophore is a straight tube without accessory secretion adhering to it. As the tubular spermatophore enters the first part of the distal vas deferens (DVD), it twists and lies apposed to the ventral epithelial wall. This twisted tube, as it extends distally, becomes folded into loops and is set on to a firm membrane, forming a continuous cord in the ventral region (Figs. 5, 8). Between the loops the spermatophoric tube tends to constrict towards the ventral region and often forms node-like structures, apparently interrupting the continuity of the spermatophoric tube (Figs. 6, 7). This arrangement is regular and is found even in the extruded spermatophoric mass. In the DVD the ventral gelatinous cord is thickened and connects the highly convoluted spermatophoric ribbon ventrally. The epithelial cells in the dorsal region of the DVD produce two typhlosole-like structures that secrete yet another material into the lumen (Fig. 9). This secretion fills up the rest of the lumen containing the spermatophoric ribbon and mixes with the secretions of the ventral epithelial cells, namely the gelatinous cord. Histology of VD The proximal portion is highly secretory, as evidenced by a very thick inner epithelial layer and a very thin o
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
