. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 316 T. A. RAWLINGS O O SEPPINGS ROSS ISLETS krl 3RAPPLER INLET 10 30 40 SHELL ^ Figure 1 . Size-frequency histograms of the first 50 \uivlla emarximitu individuals collected from each study site in March 1988. Snails smaller than cm in shell-length are not included. Wave-exposure levels were predicted to be lowest at Grappler Inlet, highest at Seppings Island, and intermediate at Ross Islets. Mean shell lengths of snails are , and cm for Seppings, Ross Islets, and Grappler Inlet populations, r
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 316 T. A. RAWLINGS O O SEPPINGS ROSS ISLETS krl 3RAPPLER INLET 10 30 40 SHELL ^ Figure 1 . Size-frequency histograms of the first 50 \uivlla emarximitu individuals collected from each study site in March 1988. Snails smaller than cm in shell-length are not included. Wave-exposure levels were predicted to be lowest at Grappler Inlet, highest at Seppings Island, and intermediate at Ross Islets. Mean shell lengths of snails are , and cm for Seppings, Ross Islets, and Grappler Inlet populations, re- spectively. Adults ofldotea (mean length = cm) were collected from Grappler Inlet in November 1988. Groups of three hlotea were placed in mesh-panelled cages (8 X 8 X 10 cm), and were then partially immersed in trays of fresh seawater. Predators were starved for an initial period of 24 h and then given five capsules from each of two snail populations (10 capsules in total). Predator preferences were tested for (1) thick versus thin-walled capsules (Grappler vs. Ross, and Seppings vs. Ross) and, (2) thick- versus thick-walled capsules (Grappler vs. Seppings). Capsules were arranged in a circular configuration, such that capsules from each population were interspersed. The number of capsules opened was recorded daily. Experi- ments were terminated when 4-6 out of 10 capsules had been opened. Five to ten replicate cages were used for each experimental combination. Results Intnispeci/ic variation in capsule morphology Snail size and capsule size. Snail size varied considerably among sites, with mean shell length increasing from wave- exposed to wave-sheltered shores (Fig. 1). Snail size at re- productive maturity also varied among populations. The smallest snails to spawn were , , and cm in shell length from Seppings, Ross, and Grappler sites respectively, even though laboratory populations greatly overlapped in size (Seppings cm; Ross: cm; Grappler
Size: 1613px × 1548px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
