The development of skeletal plates related to the ambulacral
system (adambulacral and ambulacral
plates) of the post-metamorphic settler of Echinaster (Othilia) brasiliensis occurs radially.
These transformations consist in an extreme enlargement of the paired ambulacral plates that support the fasciole and to an intense compaction of the corresponding interambulacral plates.
However, a unique path, implying only an overgrowth of the ambulacral plates supporting the fasciole, leads to the architecture of E.
The snail's defensive reaction to these species was limited to nipping at tube feet along the ambulacral
Over time, however, the interambulacral plates may be displaced by the adjacent ambulacral
miniata could potentially enhance locomotion through a proportional increase in ambulacral
area or number of tube feet, or it could impair locomotion by increasing the complexity of coordination (Hotchkiss, 2000).
Clean samples of ambulacral
fluid were obtained from the large tube feet of S.
canals, which originate from the stomodeal rings, consist of a nerve tube and an aquiferous tube and extend to the proctodeal area [ILLUSTRATION FOR FIGURE 12C OMITTED].
No significant differences were found between arms or ambulacral
areas from the same individual animal for any of the species (Student's t and Wilcoxon signed rank test).
The ridges are formed by a bundle of connective tissue and muscle fibers, called 'transverse ambulacral
muscles' (Hyman, 1955), that connect ambulacral
ossicles on opposite sides of the arm.
The eggs had a tendency to fall and were retained by the ambulacral
podia and the curved arms of the female [ILLUSTRATION FOR FIGURE 5C OMITTED].
The stem and the disk together form a functional unit: the stem allows the podium to lengthen, flex, and retract--through the action of the podial retractor muscle on the ambulacral
fluid--and the disk allows it to adhere to the substratum.