(a) aboral view, R = 66 mm; A: madreporite; B: spine (blunted); C: superomarginal plate; (b) oral view, r = 26 mm; D: actinal intermediate areas, with numerous pigmentation lacking suboral spines; E: furrow spines; F: subambulacral spines; G: inferomarginal plate; H: mouth; I: ambulacral
groove; J: adambulacral border.
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.
The snail's defensive reaction to these species was limited to nipping at tube feet along the ambulacral
Beadle (1989) measured the relative size of l SO ambulacral
plate pairs in 30 Recent E.
Total oral surface area (SA) was negatively allometric with arm length (AL) in five-armed bat stars but isometric in six-armed stars Conversely, ambulacral
groove area (GA) varied isometrically with arm length in five-armed stars but exhibited positive allometry in six-armed stars.
francis-canus were sufficiently large that individual tube feet could be seized with a hemostat, cut off, and drained into a centrifuge tube, and their ambulacral
fluid (AF) analyzed in the same way.
The early juvenile stage [ILLUSTRATION FOR FIGURE 2L OMITTED] is characterized by a complete exteriorization of the stomodeal area and of the five ambulacral
areas that end in primary podia.
huttoni, small squares of test from the ambulacral
groove were surface sterilized and treated as above.
The tube feet project from the ambulacral
groove on the ventral surface of the arm; they are cylindrical and have conical ends.
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.