Figure 4

Foetus. Specimens immersed in mineral oil (A, B, C, E: alive; F: dead); A, C, E, F: lateral view; B: ventral view; D: unfixed preparation mounted on a slide and viewed at the compound microscope with Nomarski optics. A: The foetus tends to contract, putting the head close to the posterior end of the animal; all legs are developed, including the last one (arrowhead); maxillipeds (mxp) stretch forward ventrally; brackets show extension of foregut (fg) and hindgut (hg); B: high magnification of the head (a: antennae; mxp: maxillipeds); C: specimen with light-coloured background, to get a more natural appearance, including the brownish tip of the maxillipeds (mxp); D: high magnification of mid-trunk legs with tentative identification of podomeres (tr: trochanter, pf: prefemur, f: femur, ti: tibia, t: tarsus, cl: final claw); E: high magnification of the terminal part of the trunk, showing the last leg (arrowhead), by now partially developed and segmented, and the genital segment (gs) (the wrinkled aspect of the last legs is probably a culturing condition artefact); F: specimen in which chorion (c) and exuviae (es) have not been removed but still cover the terminal part of the trunk; G: window on the beach matrix, partially showing a brood chamber: the mother (m) is still coiled around a brood of foetus juveniles (arrowhead) with her ventral surface facing outside; H: brood of foetus juveniles of panel G once the mother has escaped following the opening of the brood chamber. Scale bars: A, C, F: 500 μm; B: 300 μm; D, E: 100 μm; G, H: 1 mm.