. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. E i- 4 - IB Q. f = 2 - 0 J 30 60 90 120 Time (min) Libmia emargmata 150 180 60 90 120 Time (min) 150 180. 30 60 90 120 Time (min) 150 180 Figure 3. Mouthpurt movements of 16 crabs (mean ± SEM) during 3-h exposure to seawater concentrations of 100%, 75%, 50%, and 25% seawater; (a) Callinectes sapidus, (b) Carcinus maenas, (c) Cancer magisler, and (d) Libinia emarginata. retracted; in 75% and 50% SW the antennules remained extended for the entire experimental period (F = P < ). Although the pattern was similar i
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. E i- 4 - IB Q. f = 2 - 0 J 30 60 90 120 Time (min) Libmia emargmata 150 180 60 90 120 Time (min) 150 180. 30 60 90 120 Time (min) 150 180 Figure 3. Mouthpurt movements of 16 crabs (mean ± SEM) during 3-h exposure to seawater concentrations of 100%, 75%, 50%, and 25% seawater; (a) Callinectes sapidus, (b) Carcinus maenas, (c) Cancer magisler, and (d) Libinia emarginata. retracted; in 75% and 50% SW the antennules remained extended for the entire experimental period (F = P < ). Although the pattern was similar in Carcinus mae- nas (Fig. 6b), with the antennules exposed for longer peri- ods in all salinities below 100%, this was statistically sig- nificant only in 50% SW (F = , P < ). In Cancer magister and Libinia emarginata, the opposite response was seen: in low salinities the animals retracted the antennules. Cancer magister (fig. 6c) showed a stepwise and significant increase in antennule retraction (F = P < ) in decreasing salinities, with the antennules more-or-less re- tracted for 100% of the time in 25% SW. Libinia einar- ginata (Fig. 6d) also retracted the antennules to a greater degree (60%-80% of the time) in all salinities below 100% SW (F = , P ): only three animals were observed to extend the last segment of the abdomen in 25% SW, for short periods of time (not shown). Carcinus maenas extended the entire abdomen during the first hour in 25% SW and to a lesser degree in 50% SW (Fig. 7a), and this was usually accompanied by slow fanning movements of the abdomen; however, this was significantly different from control levels only in 25% SW (F == , P < ). Cancer magister (Fig. 7b) also extended the abdo- men in 50% and 25% SW, although the time course for this behavior was more erratic. Again, this behavior was only significantly different from the control in 25% SW (F = , P < ). Abdomen extension increased steadily
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
