The long black arms were dotted with phosphorescent patches, in red and blue and green, keyed into the nervous system. Along the ribs and flukes were two long lateral lines. The nerve-packed stripes housed a new aquatic sense that could feel the water’s trembling, like touch at a distance. The nose led to lung-like sacs packed with chemosensitive cells. The lidless eyes were huge, and the skull had been rebuilt to accommodate them.