Table 1. Summary of internal gape measurements taken on each individual predatory fish.
| Morphological measurement | Description |
|---|---|
| (a) Vertical oral gape | Vertical distance between anteriormost upper jaw (premaxilla-premaxilla joint) and lower jaw (dentary-dentary joint) |
| (b) Horizontal articular oral gape | Medial distance between the two articular bones, measured at the dorsoposterior margin |
| (c) Horizontal maxillary oral gape | Maximum medial distance between the left and right maxilla-premaxilla complexes, above the dentary articular margins |
| (d) Vertical first buccal distance | Vertical distance between the dorsal buccal cavity roof just beneath the eye, and the midpoint of the basihyal |
| (e) Horizontal first buccal distance | Horizontal distance between anterior margins of the suspensoria (i.e. between the medial faces of the ectopterygoids) |
| (f) Vertical second buccal distance | Dorsoventral distance between the 2nd basibranchial and roof of the buccal cavity |
| (g) Horizontal second buccal distance | Maximum horizontal distance between the 1st gill arch (1st ceratobranchials) |
| (h) Vertical pharyngeal jaw distance | Dorsoventral distance between the upper and lower pharyngeal jaws (3rd,4th pharyngobranchials and 5th ceratobranchials) |
| (i) Horizontal 4th gill arch distance | Horizontal distance between the 4th ceratobranchials |
| (j) Anterior esophagus vertical distance | Dorsoventral distance between the inner walls of the anterior region of the esophagus, located posterior to the pharyngeal apparatus |
| (k) Anterior esophagus horizontal distance | Lateral distance between the walls of the anterior region of the esophagus, located posterior to the pharyngeal apparatus |
| (l) Posterior esophagus vertical distance | Dorsoventral distance between the inner walls of the esophagus located anterior to the stomach |
| (m) Posterior esophagus horizontal distance | Lateral distance between the inner walls of the esophagus located anterior to the stomach |
| (p) Vertical distance of pectoral girdle | Distance between the ventral side of the spinal cord at the pectoral girdle, and the lowest point on the medial margin of the pectoral girdle (where the cleithra join) |
| (q) Horizontal distance of pectoral girdle | Maximum distance between the medial faces of the cleithral bones |
| (n1) Anterior stomach | Maximum distance between the inner walls at the anterior end of the stomach |
| (n2) Mid stomach | Maximum distance between the soft tissue walls at the point where the stomach connects to the intestine |
| (n3) Posterior stomach | Maximum distance between the inner walls at the posterior end of the stomach |
The order of measurements is shown according to the order they were taken. Each of these measurements was taken for both first resistance, and mechanical maximum, distending tissues until resistance prevented further movement with light pressure. For an illustration of the measurements on a fish, please see Fig 1.