Fig 1.
Morphological gape measurements.
A) Gape measurements of the oral, buccal, pharyngeal, and pectoral girdle area. B) Gape measurements of the esophagus and stomach. For a detailed description of the measurements, please see Table 1. Please note k, m, and n are internal horizontal measurements.
Table 1.
Summary of internal gape measurements taken on each individual predatory fish.
Fig 2.
Prey processing by predatory fishes.
A) the predator Cephalopholis urodeta (SL = 98.4), ingesting a 52.7 mm SL, 27 mm MD Acanthochromis polyacanthus in a horizontal, head-first position, and B) a 109 mm SL Paracirrhites forsteri that failed to swallow a 45.6 mm SL, 23.1 mm MD, A. polyacanthus.
Fig 3.
Regression Tree Analysis on key gape measurements.
A) Cephalopholis urodeta, B) Paracirrhites forsteri, C) Pterois volitans, and D) Lates calcarifer. Measurements (x-axis) are displayed in terms of % of SL (y-axis) (mean ± SE), where shaded horizontal lines represent groupings resulting from the Tree Analysis. Measurements are also grouped into oral (O.), buccal (B.), pharyngeal (P.), pectoral girdle (P.g.), esophagus (E.), and stomach (S.). Colors in graphs represent terminal nodes partitioned by the Regression Tree models.
Fig 4.
Gape measurements of predators relative to maximum prey size.
Gape measurements of A) Cephalopholis urodeta (n = 3) and B) Paracirrhites forsteri (n = 3) in terms of % SL (mean ± S.E), compared to the mean maximum depth of the largest prey successfully swallowed. Black bars show the vertical oral gape (see `a`Table 1, Fig 1), while grey bars (b, c, e, g, i, q) show hard structure measurements, and white bars (k, m, n1, n2, n3) soft tissue measurements. The red line indicates the mean maximum prey size as a % of predator SL (± S.E dashed lines). The blue line is the mean maximum prey size after accounting for the compressibility of prey (compressed MD).
Fig 5.
Compressibility of Acanthochromis polyacanthus.
A) Scatter plot of SL (x-axis) and MD (y-axis) of A.polyacanthus. Red dots represent natural (non-compressed) MD for individuals, while blue dots represent compressed MD for the same individuals when compressed by a set of calipers with approximately 2.9 N across all sizes. B) Scatter plot of SL (x-axis) and compressibility of individuals, in terms of their ability to be compressed from their natural (non-compressed) MD relative to their size.
Fig 6.
Percentage of successful head-first, mid-body first, or tail-first strikes.
A) Cephalopholis urodeta (n = 14), and B) Paracirrhites forsteri (n = 18).
Table 2.
Summary of predicted and experimental maximum prey size (maximum depth) as a percentage of predator SL.