Dka. Barnes et P. Rothery, COMPETITION IN ENCRUSTING ANTARCTIC BRYOZOAN ASSEMBLAGES - OUTCOMES, INFLUENCES AND IMPLICATIONS, Journal of experimental marine biology and ecology, 196(1-2), 1996, pp. 267-284
Over 4000 bryozoan-bryozoan interactions were recorded from a total of
985 rocks from six locations at Signy Island in the maritime Antarcti
c. The majority of these interactions were interspecific meetings. The
identity of the competitive species was a major influence on the outc
ome of encounters, whereas depth and surface area of rocks had little
significant influence. The assemblage of bryozoans could be ranked int
o a clear hierarchy with a competitively dominant species. Zooidal hei
ght and colony growth morphology were found to be important factors in
overall overgrowth rank. Few interspecific encounters resulted in ind
eterminate outcomes, but a tied outcome was found to be most likely be
tween competitors of similar overgrowth rank. In contrast, intraspecif
ic meetings mostly resulted in tied outcomes. Species with a higher pr
oportion of colonies on the upper surfaces of rocks were found to have
a lower incidence of tied outcomes. One explanation may be the potent
ially more successful larval dispersal on upper rock surfaces in highe
r water flow, and the resulting decreased likelihood of neighbours bei
ng related. Several incidences of homosyndrome were also observed in t
hree bryozoan species.