Fig. 2

Series of selected frames from time-lapse 1 (Additional file 3: File S3) of an embryo imaged under halocarbon oil at room temperature (20 °C). Photographs were taken every 15 min. A: Stage 4, three-day old embryo, at the onset of perivitelline space formation. B: Stage 5/6, undergoing cell movements. C: Stage 7, with a ventral segmented germ band. D: Stage 8, limb bud protrusion. E: Stage 9, appendage elongation and further formation of opisthosomal segments. F: Stage 10: Ventral inflexion of the opisthosoma. The diameter of the egg is approximately 550 µm. Timing of development is slower than the staging given the cooler temperature at which the embryo was imaged. D and V: dorso-ventral axis; ch: cheliceral segment; L2: leg 2 segment; pp: pedipalpal segment