Neurons in the adhesive disc and brachia merged with the basi-epithelial plexus underlying the entire attachment complex (Fig.
The brachia of the three species investigated here have an abundance of serotonergic (Chee and Byrne, 1999b) and IE11 immunoreactive cells.
The developing brachia appeared as three bulges (Fig.
Their minute larvae have a reduced brachiolar complex comprising three small nonsticky protrusions that cannot function in attachment, and some embryos do not develop brachia at all.
hystera exhibited exploratory settlement behavior and attached to the substratum with their brachia and adhesive disc prior to metamorphosis, in a manner typical of planktonic asteroid larvae.
The embryos are now early brachiolariae with three recognizable arms, or brachia [ILLUSTRATION FOR FIGURES 1D, 2B OMITTED].
Differential growth of the lateral brachia results in the formation of three arms equal in length.
Hatching occurs 5-6 days after fertilization and, by this time, the brachia are noticeably muscular and extend through breaks in the envelope to attach to the substratum.
In response to a strong current the brachia stretch in the direction of flow, and only concentrated flow from a pipette will dislodge the larvae.