. Bulletin of the Natural History Museum Zoology. 16 SIEBERT region. The second section, consisting of the intestine, is separated from the oesophagus-stomach by an obvious sphincter, and meas- ures approximately 73% of total gut length. The anterior third of the intestine is marked by irregular folds, which are more vertically oriented and regular in the region of the air bladder and parapelvic bones. Posterior to the air bladder the folds are regular, nearly vertical, and wavy. They appear to encircle the gut so that the posterior half of the intestine looks very much like the external
. Bulletin of the Natural History Museum Zoology. 16 SIEBERT region. The second section, consisting of the intestine, is separated from the oesophagus-stomach by an obvious sphincter, and meas- ures approximately 73% of total gut length. The anterior third of the intestine is marked by irregular folds, which are more vertically oriented and regular in the region of the air bladder and parapelvic bones. Posterior to the air bladder the folds are regular, nearly vertical, and wavy. They appear to encircle the gut so that the posterior half of the intestine looks very much like the external appearance of an earthworm. The end of the intestine is conical and projects slightly into the third section. The third section of the gut is short, less than 10% of total gut length and is slightly greater in diameter than the intestine. It also is characterised by wavy, vertical folds, but these are more numerous (distinctly closer together) and more wavy than those of the Gonads The gonads lie dorsal to the gut and when mature occupy nearly the entire length of the body cavity, as described forS. praecox (Roberts, 1981). Testes exhibit the vertical striations characteristic of at least some other clupeomorphs (Roberts, 1981; Whitehead & Teugels, 1985). Judging from enlargement of posterior sections of testes in some individuals, maturation of testes proceeds from posterior to anterior. Ovaries contain eggs of distinct size classes, egg size presumably being an indication of degree of egg maturation. One female contained 18 very large eggs, nine in each ovary arranged in a single file. These eggs were slightly wider than the width of two myotomes (nearly 1 mm in diameter) and occupied nearly the entire length of the ovaries. Smaller eggs of two distinct size classes were interspersed among the larger eggs (Fig. 4). Among clupeomorphs the presence of distinct size classes of eggs in ovaries is considered indicative of repeat spawning within a single breeding se
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Keywords: ., bh, bookcentury1900, bookcollectionbiodiversity, bookleafnumber18
