We observed an avicularium stab a newly settled veliger crawling on the colony and saw the lophophore of a bryozoan take in a swimming veliger, causing the latter to retract its velum and sink to the bottom of the culture dish.
pacifica until 3 days after metamorphosis, though it repeatedly touched, and caused the retraction of, a lophophore on day 2.
According to Fursich and Hurst (1974), spiriferinid brachiopods such as Liospiriferina have the most efficient lophophores
and thus are favored under the here described low energy/low food supply conditions.
Scientists have presumed that the larger brachiopods have a food-intake handicap, reasoning that the bigger the brachiopod, the smaller the surface area of its filter-feeding organ, or lophophore
, in relation to the animal's overall volume.
These suggestions were based primarily on observations that chimney spacing is reduced in colonies found in sites with high environmental current speeds (Okamura and Partridge, 1999), and in colonies in which spines have formed between the lophophores
Remodeling of this system could result from changing the extension or orientation of lophophores
, from degeneration of feeding zooids, or from regeneration of nonfeeding zooids.
Incurrent velocity as a function of distance from the lophophores
was measured for four particles for each of two colonies for each spacing treatment at 0 cm [s.sup.-1].
membranacea within the paternal coeloms (perivisceral and lophophoral), in seawater after spawning, and within the lophophores
Thus, although colonies showed a progressive miniaturization by producing smaller, more closely spaced lophophores
with increased flow, there was no apparent effect of flow on growth rates at the two sites in which we were able to assess growth.
A priori, the former reason appears less satisfactory given that lophophore
size decreases significantly as a function of larval swimming duration (Wendt, 1996) and that smaller lophophores
generate currents with lower velocities (Best and Thorpe, 1986).
Several workers have postulated that the lophophores
of brachiopods, bryozoans, and phoronids are homologous to the tentaculate arms of pterobranch hemichordates (3-8), leading to phylogenetic hypotheses that support the notion of homology among these structures (8, 9).
posidoniae, Silen reported that spawned sperm caught by lophophores
of neighboring colonies became attached to the abfrontal sides of the tentacles.