Onset of Buccal Pumping in Catshark Embryos: How Breathing Develops in the Egg Capsule
A. Schematic diagram of the pharyngeal skeletal and muscular elements of the adult cloudy catshark. B. 3-dimensional reconstructions of pharyngeal skeletal and muscular elements made from histological thin sections. Ventral view of the jaw and pharyngeal skeletal elements (blue) and the hyoid retraction muscle (coracohyoideus; red) in 27.2 mm TL (i), 29.2 mm TL (ii), 32.8 mm TL (iii), and 39.8 mm TL (iv) embryos. Scale bars = 500 µm.