Cyclograpsus cinereus — Costlow and Fagetti 
175 
Larval Development 
The frequency of molting during the five 
zoeal and one megalops stages is shown in 
Figure 7. The first and second molts of most 
larvae were confined to two days at all four 
salinity-temperature combinations. By the time 
of the third molt, however, the uniformity was 
not as apparent and the later molts were spread 
over three, four, and five days. Figure 8 shows 
the time required for development of the five 
zoeal stages and megalops of C. cinereus when 
maintained at combinations of two salinities 
and two temperatures. At 20° C, the duration 
of all larval stages is longer than that observed 
for larvae reared at 25 °C This difference is 
more pronounced as development continues 
and is quite apparent for the megalops stage. 
Within the two salinities used, 30 and 35 ppt, 
there is no apparent difference in the time 
required for development of the larval stages 
(Fig. 8). The average time for total develop- 
ment to the first crab (Fig. 8) at 25 °C was 
30 days at 30 ppt and 34.2 days at 35 ppt. At 
20°C and 30 ppt, 45.7 days were required and 
at the same temperature and 35 ppt comparable 
development required 47.7 days. 
Mortality of the individual larval stages is 
shown in Figure 9. Although larvae were main- 
50 
45 
40 
35 
30 
30 ppt. 35ppt . 
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TEMPERATURES. 
Fig. 8. Comparison of the duration of five zoeal 
stages and megalops of Cyclograpsus cinereus Dana 
reared in the laboratory at different salinities and 
temperatures. 
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Fig. 9- Comparison of the mortality of the five 
zoeal stages and megalops stage of Cyclograpsus 
cinereus Dana reared in the laboratory at different 
salinities and temperatures. 
