Japigny Meunier, Jégu & Keith, 2011

Peixoto, Luiz Antônio Wanderley & de Pinna, Mário, 2022, Patterns of diversification and phylogenetic structure in the dorsolateral head musculature of Neotropical electric eels (Ostariophysi: Gymnotiformes), with a myological synonymy, Neotropical Ichthyology (e 210009) 20 (1), pp. 1-117 : 48

Japigny Meunier, Jégu & Keith, 2011

Adductor mandibulae. The rictalis originates in the preopercle, sympletic, and hyomandibula. The lateralmost fibers of the ventral portion of the rictalis is restricted to the anterior margin of the preopercular fossa. That section inserts solely on the coronoid process, with some lateralmost fibers associated with the buccopalatal membrane. The stegalis arises from the hyomandibula, pterosphenoid, parasphenoid, metapterygoid, and sympletic; and converges into the meckelian tendon which, in turn, inserts on the coronomeckelian bone, with some anterodorsal fibers converging to the mandibular tendon. The stegalis overlaps only the posterior portion of the basal region of the endopterygoid not overlapping it completely.

The segmentum mandibularis arises from the mandibular tendon, enters the mandible mesially and inserts on the anguloarticular. The segmentum mandibularis is located dorsally to Meckel’s cartilage, extending about 60% of the dorsal portion of this cartilage. The course of the ramus mandibularis trigeminus nerve is lateral to the stegalis and mesial to the rictalis and malaris.

Levator arcus palatini. The levator arcus palatini has a roughly parallelogram shape, originating from the ventral margin of the frontal and sphenotic and inserting onto the hyomandibula. The origin of the levator arcus palatini is slightly narrower than its insertion ( Fig. 20 ). At the insertion of the levator arcus palatini, all fibers are located laterally to the malaris; and with only the posterodorsal fibers being mesial to the dilatator operculi, where the anterior margin of the dilator operculi does not exceeds the medial portion of the levator arcus palatini.

Figures

FIGURE 20 | Lateral view of dorsolateral musculature of Japigny kirshbaum (Sternopygidae), FMNH 50185, 137.2 mm LEA. Anatomical abbreviations in Tab. 1. Scale bar = 4 mm.