. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DRIP z UJ O or 100 -i 50 -. DRY MHWN MLWN TIDAL HEIGHT FIGURE 2. Percent cover of Chthamalus (open circles) and Semibalanus (solid squares) as a function of tidal height on transects at the Yale Field Station in Guilford, Connecticut. Tide levels marked as in Figure 1. The two panels are from parallel transects 25 cm apart. Upper panel transect has water seepage from a deep crevice in the rock surface located at the position of the arrow. Lower panel transect is dry. Note the upward displacement of Semibalanus in the damp ar
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DRIP z UJ O or 100 -i 50 -. DRY MHWN MLWN TIDAL HEIGHT FIGURE 2. Percent cover of Chthamalus (open circles) and Semibalanus (solid squares) as a function of tidal height on transects at the Yale Field Station in Guilford, Connecticut. Tide levels marked as in Figure 1. The two panels are from parallel transects 25 cm apart. Upper panel transect has water seepage from a deep crevice in the rock surface located at the position of the arrow. Lower panel transect is dry. Note the upward displacement of Semibalanus in the damp area below the water seepage. Chthamalus on vertical surfaces was near mid tide level, in the zone where indi- viduals usually die as a result of overgrowth by Semibalanus (Fig. 4). There was very little settlement in the Chthamalus zone itself (Fig. 4). On horizontal surfaces, settlement was most intense near mid tide level, in the zone where Semibalanus died as a result of summer heat (Fig. 4). Semibalanus removals were established in August, and settlement of Chthamalus occurred prior to the October samples (Fig. 4). These sites were surveyed at the end of April, at the height of the Semibalanus settlement season. Semibalanus had settled at densities in excess of 50 per square centimeter. In the vertical sites (Figs. 1,4), at all but the highest shore levels, Chthamalus, in the Semibalanus removal quadrats, were overgrown by newly settled 2-week-old Semibalanus. When the nearly 100% cover of newly settled Semibalanus was removed with a toothbrush, live Chthamalus were found beneath it. Presumably these totally smothered Chthamalus, although tolerant of desiccation (Foster, 197 la), would die within a few weeks with no direct access to food, water, or oxygen. Approximately 5% of the live Chthamalus (approximately 5 mm diameter) were being undercut (sensu Connell, 196la), lifted from the substratum, and expelled from the growing surface of Semibalanus spat (approximately 1 mm di
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
