In total, it takes around 22 days at 17 [degrees]C to produce a functioning zooid
through blastogenesis (Berrill, 1947).
Colonies include three blastogenetic generations represented by mature, filter-feeding zooids
, primary buds on zooids
, and secondary buds (budlets) emerging from the primary buds (Manni et al., 2007).
Newly metamorphosed colonies can be aged, because it takes approximately one day for metamorphosis to proceed from initial settlement of the larvae to development of feeding lophophores in the twinned initial zooids
of the colony.
Colonies also vary in total sperm production because they vary in size (number of zooids
), which in turn varies during colony ontogeny.
Water temperature affects zooid
size and growth rate in bryozoans over a range of scales.
intermedium feeding primarily on the haptophyte algae Isochrysis galbana, the development of colonies originated from a single zooid
was observed over a period of 96 hours.
Most individuals settled and developed one zooid
within 19 h; however, a significant (P [less than] 0.0001, ANOVA/SNK) 27-34% of the individuals in the 1, 5, and 10 [[micro]gram]/mL treatments were metamorphosed but deformed relative to the controls [ILLUSTRATION FOR FIGURE 8 OMITTED].
Endobugula sertula" ensure a high concentration of the defensive compounds or the bryostatin-synthesizing symbionts in the ovicell-bearing zooids
. To identify host genes potentially involved in these processes, we used suppressive subtractive hybridization (SSH) to examine differentially expressed B.
With breeding data on living populations of these species, we estimate: (1) environmental and genetic components of the phenotypic variation in ten traits of zooid
skeletal morphology, and (2) the heritability of within-colony environmental variability in each trait as a possible vehicle for preserving genetic variation.
For clonal organisms such as Bryozoa that grow by budding modules (zooids
), which together form a colony, phenotypic variance components form a partial record of ancestry from which genetic parameters can be reconstructed.
After fertilization, early embryogenesis proceeded in the ovary of the mother zooid
. There were several blastomeres that contained many yolk granules heavily stained with toluidine blue.
The last two aspects are particularly intriguing, because the regions of the adult where budding is initiated have different ontogenetic origins and certainly do not contain every adult cell type of the parental zooid
. For example, in species that undergo stolonial budding, the morphogenetic part of the bud originates from the niesenchyme-derived septum located within the stolon (Fig.