. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. Molt stages ns »- 10 Figure 9. Proecdysis. stage D:. New barbules (b) are present on all new setae (ns). (lOOx), scale bar = 30 ^m. Figure 10. Proecdysis, stage D,. The pattern of new setae (ns) is interrupted by folds of the epidermis (ep). The animal is ready to molt in this stage. (120x) scale bar = 40 nm. The crustacean molting cycle: setogenesis Although setogenesis has been used as a criterion for molt staging for many years (see Drach, 1939). species variations in setal morphology and development result in differences
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. Molt stages ns »- 10 Figure 9. Proecdysis. stage D:. New barbules (b) are present on all new setae (ns). (lOOx), scale bar = 30 ^m. Figure 10. Proecdysis, stage D,. The pattern of new setae (ns) is interrupted by folds of the epidermis (ep). The animal is ready to molt in this stage. (120x) scale bar = 40 nm. The crustacean molting cycle: setogenesis Although setogenesis has been used as a criterion for molt staging for many years (see Drach, 1939). species variations in setal morphology and development result in differences among crustaceans in both staging criteria and in easily-defined subdivision of the molt stages. We have established criteria for the molt stages and substages in P. vannanu'i. These criteria include the discernment in the pleopods of the epidermis, setal lumens, internal cones, and setal organs (see Figs. 1-10). Similar criteria have been used to determine stages for the penaeidae shrimp P. ciiliforniensis, P. stylirostris (Huner and Col- E 1 c . Q. _>. O <u. 10 Time (days) Figure 12. Total protein levels in the hemolymph of juvenile P. vunnamei during the molting cycle. Values represent mean ± (n > 12 for each point). vin. 1979). P. mcrguiensis (Longmuir. 1983). P. duor- arum (Schafer, 1968) and P. esculentns (Smith and Dall, 1985). Setogenesis in these shrimp species differs primar- ily in the degree of pigmentation in the appendages and in the duration of the molt stages. Furthermore, the com- plete retraction of the setal matrices was observed in other penaeids during anecdysis, whereas in some indi- viduals of P. vannanu'i retention of setal matrices was observed. Deviations in setogenesis are even more pro- nounced in other decapods. For example, in the lobster Panulims nuirginulm. internal cones are lacking; thus. AB c Molt stages C O) Q. c > I V c o (A •D O 4> .c Q. "5 o 250 - 200 - 150 - 100 • 50 - • i D D D D D 0 — 1'— 1"
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
