Blackedged Blaasop

Arothron immaculatus (Bloch)

The posteroventral part of A 1α is expanded along the floor of the orbit, and A 1α covers A 2α laterally. A 2β is well developed, and A 3 is much reduced (particularly dorsally). The anterior part of the dilatator operculi inserts on the subopercle and opercle.

The posterodorsal bundle of the hyohyoidei adductores attaches to the anteroventral face of the supracleithrum.

The fibers of levator externus I insert only on epibranchial 1, and adductores II and V are absent.

The residual inclinator analis has fused with the obliquus inferioris, and the first and last anal fin rays have inclinators attaching to their bases.

The hypochordal longitudinalis is as for A. honckenii. The single tendon of the transversus caudalis attaches to the base of ray V 2. The flexor ventralis attaches to the bases of rays V 1–5.

The posterodorsomedial bundle of the obliquus inferioris fades into an aponeurotic sheet at the level of the anal fin, the sheet attaching to the haemal arches of the thirteenth and fourteenth vertebrae.