Petraliellidae) colonies have fully calcified frontal walls with a small avicularian complex (a modified autozooid) present below the operculum (Stach, 1936; Cook and Bock, 2002; Tillbrook and Cook, 2005).
In the present study, the level of connectedness between functional autozooids did not increase with polymorphism in two species of extant Bryozoa, challenging the legitimacy of assumed positive relationships between levels of within-colony specialization and physiological integration.
However, the slopes of the regression lines for autozooid number as a function of days after metamorphosis were statistically indistinguishable; an indication that both groups of colonies were growing at about the same rates, despite differences in the absolute number of autozooids at day 14 [ILLUSTRATION FOR FIGURE 5 OMITTED].
The observed difference in the rates of autozooid budding is probably a result of a delay in the time to first bud, because the increased larval swimming period undoubtedly uses energy that would otherwise go to form the first autozooid.
Rachis pieces of about 5 x 5 mm (including autozooid polyps) were excised from colonies anesthetized in a 1:1 mixture of 0.37 M Mg[Cl.sub.2] and seawater.
To ensure that the uncoupling agents did not interfere directly with the luminescence effector of the photocytes, the latter were dissociated by incubating photocyte-rich autozooid tissues for 1 h in a medium containing 37.5 mg papain, 5 mg dithiothreitol (both from Sigma), 5 ml of ASW, and 5 ml of 0.37 M Mg[Cl.sub.2] at pH 8.0 (Holman and Anderson, 1991).
The polyps are dimorphic, featuring both autozooids and siphonozooids.
Cross-sections of the Sarcophyton auritum polypary 2-3 mm below the surface featured a uniformly pale-turquoisestained coenenchyme, found between the autozooids (hereafter termed "polyps") and the siphonozooids (Fig.
fuscus may preferentially settle on or crawl up to the distal-most autozooids
before metamorphosing, to avoid interactions with avicularia.
At the level of the colony, bryozoans are simultaneous hermaphrodites; individual autozooids
, however, generally express gender sequentially, first maturing male, then female, gonads.