. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 658 VALIELA ET AL. (Ono, 1968, and our own observations). We have observed males feeding under- water in Massachusetts and Teal (1958) saw crabs feeding during high tides in Georgia. In the marshes of Buzzards Bay along the coast of Massachusetts, mud flats and grass-covered habitats in which Uca feed are exposed for about four hours at low tide. We have observed that as high tide approaches only males are still feeding. This agrees well with our results of prolonged feeding with males. The two-fold increase in feeding durat
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 658 VALIELA ET AL. (Ono, 1968, and our own observations). We have observed males feeding under- water in Massachusetts and Teal (1958) saw crabs feeding during high tides in Georgia. In the marshes of Buzzards Bay along the coast of Massachusetts, mud flats and grass-covered habitats in which Uca feed are exposed for about four hours at low tide. We have observed that as high tide approaches only males are still feeding. This agrees well with our results of prolonged feeding with males. The two-fold increase in feeding duration would seem to be enough compensa- tion for lack of a feeding appendage. However, the morphology of the feeding claw is such that males may be able to grasp and feed on larger mouthfuls per feeding motion. Longer feeding periods may expose males to greater predatory mortality. However, in a sample of 713 specimens of U. from Great Sippewisset Marsh there were more males than females present ( females). This sex ratio was very similar to that found by Shanholzer (1973) in a salt marsh in Georgia and is not unusual among marine invertebrates (Wenner, 1972). Data now in preparation from Great Sippewissett show greater mortality of the smaller females than males. The need to repeatedly expose eggs to the flow of well- oxygenated water may increase the exposure of berried females to predatory mortality by forcing females to remain in the relatively unprotected creek banks at high tide. The egg masses also may impede locomotion of females and increase I h- Q ^ \- o Q Males y = + ,r Females y = + , r = 12 13 14 15 16 17 18 CARAPACE WIDTH (MM) 19 20 FIGURE 2. Width of the tip of the feeding dactyl versus carapace width in male and female Uca pugnax. The lines show the calculated regression line for the Please note that these images are extracted from scanned page images that may have been digitally enhanced f
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
