Largegill Trumpetsnout

Inhabits trawling grounds (Ref. 3132).

Macrorhamphosodes platycheilus Fowler

The larger specimen had the mouth twisted some 55 degrees to the left, while that of the smaller individual was twisted to a lesser extent to the right. No differences that could be correlated with the side to which the mouth was twisted were found, except in the adductor mandibulae. Here A 1 appears to have completely replaced A 2α, and includes the anterior faces of the preopercle and hyomandibular in its sites of origin. A 3 is absent. In both examples a single tendon passes anteriorly and splits into two smaller ones. One of these inserts on the anteroventromedial face of the dentary, while the dorsal division attaches to the posteromedial face of the maxilla. The tendon to the maxilla is divided into two sections on the side to which the mouth is twisted, but not on the opposite side.

Owing to the considerably modified snout, the origin of the ptotractor hyoidei has shifted mainly to the ventral faces of the interopercles and the thick connective tissue surrounding them. The origin extends a third of the way along the snout before grading into a single medial tendon which courses anteriorly between the interopercles to attach broadly to the ventromedial faces of the dentaries. The intermandibularis and hyohyoideus inferioris are as described for Tydemania.

Figure 59 gives a general view of the branchial arch muscles not originating on the arches themselves, and is included to illustrate topographical differences too slight to be discussed in the text. The adductor radialis originates only from the second radial, and inserts on the lowermost pectoral ray. Inclinatoves dorsales to the spiny dorsal fin are absent, and only the first two spines have erector and depressor muscles. The interradialis is better developed, and the flexor dorsalis inserts on caudal rays D 1–6. There is less continuity between the sternohyoideus and the anteroventral component of the obliquus inferioris, mainly because the ventrolateral border of the cleithrum and the dorsolateral surface of the pelvis are very close to one another.