Lateral lips with two pairs of adoral
setae (12), setiform, barbed.
Two pairs of setiform, distally curved, barbed adoral
Surgical removal of the adoral
lobe disrupts these and other settlement behaviors and delays the onset of metamorphosis in response to bio-film, providing experimental evidence that this region of the larva is specialized for functions other than increasing clearance rates or swimming speed.
In the oral region, two clusters of cells corresponded to the adoral
CB nerve and ganglion (Fig.
Three days after insemination, both types of larvae had adoral
ciliary bands in which cilia swept toward the mouth.
The presence of serotonergic adoral
ganglia along the posterior rim of the mouth of asteroid, ophiuroid, and echinoid larvae is likely to be a convergent feature, given our current understanding of echinoderm class interrelationships (3).
The jaws of both males and females, present at each interradius, consist of one tooth, one oral shield, two adoral
shields, two oral plates with infradental papillae, and two buccal scales.
The presence of a nervous system in echinoid larvae was first suggested by observations of a putative thickening in the apical area (MacBride, 1914) and the presence of neuron-like cells in the adoral
ciliary band (Mortensen, 1921).
On the ventral surface, the cells around the stomodaeum, about 10 in number, were monopolar and marked the position at which the adoral
ciliated band will form [ILLUSTRATION FOR FIGURE 2A OMITTED].
These are the apical cilia (AC), inner preoral cilia (IPC), outer preoral cilia (OPC), and adoral
Groups of interambulacral plates were excised from three regions on the skeleton: adapical, ambital, and adoral
. The ambital region was defined to be four plates wide, centered at the widest diameter of the urchin.
When stimulated by the manipulator arm of a submersible or by very bright lights, this same species, Endoxocrinus parrae, rapidly flexes some or all of its arms in an adoral
direction (Messing et al., 1988; Young and Emson, unpub.).