. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. COMPETITION BETWEEN BRYOZOAN CLADES 87 Table 1 Mean number of species per rock and proportion of rocks (in pari'nihi'scx) ci>li>ni:ril hy species occurring rarely ui tilt' Miul\ \ites, Altisku Mean no. species per rock Tidal cover/depth Cyclostomatids Ctenostomatids Cheilostomatids Upper midlittoral Lower midlittoral 0 () () () () () Upper infralittoral Lower infralittoral () () () () 1(1,7() () Measurement of interactions All colo
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. COMPETITION BETWEEN BRYOZOAN CLADES 87 Table 1 Mean number of species per rock and proportion of rocks (in pari'nihi'scx) ci>li>ni:ril hy species occurring rarely ui tilt' Miul\ \ites, Altisku Mean no. species per rock Tidal cover/depth Cyclostomatids Ctenostomatids Cheilostomatids Upper midlittoral Lower midlittoral 0 () () () () () Upper infralittoral Lower infralittoral () () () () 1(1,7() () Measurement of interactions All colony-to-colony interactions between representa- tives of the three clades of bryozoans were recorded from each rock and site, along with the number of intraspecific and interspecific encounters within clades. When the grow- ing edge of competitor A covered the apertures of compet- itor B, A was determined to have overgrown B. Only "frontal" overgrowth interactions between two living com- petitors, without direct settlement onto one of the compet- itors, was counted as overgrowth for the purposes of this study (see Rubin, 1982; Turner and Todd, 1994; Barnes and Rothery, 1996). The actual scores were tabulated into a competitor-contact matrix (as Turner and Todd, 1994; Barnes and Rothery, 1996). Measurements of overgrowth performance were calculated for each competitor that took part in more than 20 between-clade interactions. Various measurements of overgrowth performance were used: a score system in which a win = 3, a tied outcome = 1. and a loss = 0 (wins rated much higher than ties because ties often prevent further growth and development of colonies, see Barnes and Clarke [1998]); the number of wins divided by the total number of interactions for that competitor; the number of losses divided by the total number of interactions for that competitor; the number of wins divided by the number of losses for that competitor; and an aggregate measure in which the mean of the
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
