Amoeba proteus displays a walking form of locomotion

Abstract

This report deals with observations on the directional locomotion of amoeba before and after fixation and scanning electron microscopy. The study was aimed at visualization of the stepwise events of directional movements. After the analysis of the data it is proposed that the amoeba undergoes a sequence of movement events that can be defined as a walking form of locomotion.

Formation of multicellular colonies by choanoflagellates increases susceptibility to capture by amoeboid predators

“…We found that pseudopodium extension by A. proteus was pulsatile (Figure 3), with peak speeds during pulses of extension ranging from ~3 to 17 mm s −1 (Figure 7B), and with time‐averaged extension speeds of ~1–5 mm s −1 (Figure 7A). These mean speeds are in the same range as published crawling speeds of A. proteus (Cameron et al, 2007; Folger, 1925; Mast & Prosser, 1932; Mast & Stahler, 1937; Miyoshi et al, 2003), but are faster than lamellipod extension by Dictyostelium amoebae (Schindl et al, 1995). We found that neither the peak nor mean speeds of pseudopodia varied with prey size (Figure 7).…”

“…It has long been known that amoebae crawl and capture prey using pseudopodia, which are temporary arm-like extensions of the cell (e.g. Cameron et al, 2007;Dellinger, 1906;Gibbs & Dellinger, 1908;Kepner & Taliaferro, 1913;Mast, 1926;Schaeffer, 1916bSchaeffer, , 1917. The cellular mechanisms and biophysics of pseudopod extension and amoeboid crawling have received much attention (e.g.…”

Mechanical transformations of living cavitary bodies

“…When the internal pressure drops, it is the tail plasmalemma that should be the first to be deformed ("wrinkled") by the pressure of water from the outside. Therefore, the depressions at the tail end of a moving amoeba or at the tip of a retracting pseudopodium (Cameron et al, 2007) may be considered as invaginations arising under the pressure of the outer liquid. A-A2: Alternating stages of the locomotor cycle.…”