Figure 5. The angle of first turn-to-prey is experience-dependent.

(A) Hunting sequences begin with eye-vergence and a turn bout that re-orients larvae toward prey. We isolate the initial re-orientation toward prey as shown in an example hunting trajectory, which is drawn relative to the larva’s heading and mouth position (center), and color coded corresponding to eye-vergence. A large amplitude turn that re-orients it toward prey coincides with an increase in eye-vergence angle. Inset shows turning over time, with red highlighting the extracted first-turn behavior and light grey indicating post-capture turn. (B–D) Prey azimuth vs magnitude of re-orienting first-turn data points along with regression lines (dark), and 5–95% confidence intervals (light), according to a linear fit. Hunt events from the LF group show the highest deviation from dotted line, which indicate the slope of turn angles that would precisely align larvae with prey. (E) The inferred slope density from the linear statistical regression model reveals that the mean first-turn behavior (γ) of hunt events pooled from the LF group have a lower slope than NF ($P[{\gamma }^{LF}<{\gamma }^{NF}]=1$), and DF ($P[{\gamma }^{LF}<{\gamma }^{DF}]=1$), while DF shows the least undershooting ($P[{\gamma }^{NF}<{\gamma }^{DF}]=0.90$). The ranking in mean turn-ratios according to pooled data across individuals goes LF>NF>DF, but this can be biased toward more active individuals within each group, see Figure 7 where group behavior is estimated without this bias.

Figure 5—figure supplement 1. The distributions of prey azimuth at the onset of successful hunting episodes are similar between groups, and favor prey on the lateral visual field.

Prey azimuth at start of successful hunting event (azimuth of prey detection). Differences in undershooting are not due to differences over the angle at which prey are being detected. Estimated density of prey detection angle (BW = 10°) shows that the hunt data across groups have similar bimodal distributions of initial prey-detection azimuth, with peaks around 30°-50° on either side of the midsaggital axis.

Figure 5—figure supplement 2. Turn-ratio histogram per group also show undershoot bias for LF.

Histogram of turn-ratio data confirms that hunt events from the LF group have a bias towards turn ratios below unity (undershooting).