Fig. 1From: The complex simplicity of the brittle star nervous systemBrittle star arm anatomy. a An individual of O. brevispinum. b Scanning electron micrograph of the oral arm surface of A. kochii. c and c’ Cross section of the arm of A. kochii. c The arm was embedded into epoxy resin and sectioned transversely. The resin was then removed, and the cut surface was imaged with a scanning electron microscope. c’ The corresponding plastic section stained with methylene blue. d and d’ Longitudinal paragsagittal sections through the arm in A. kochii stained with methylene blue. The skeletal elements are not visible in any of the micrographs, because they were removed during tissue processing. Abbreviations: ac – arm coelom; am – aboral intervertebral muscle; as – aboral shield; il – intervertebral ligament; ljn – lateral juxtaligamental node; om – oral intervertebral muscle; os – oral shield; pd – podium; pmn – hyponeural proximal muscle nerve; rnc – radial nerve cord; s – spine; ts – tentacle scale; wvc – water-vascular canal; v – vertebral ossicleBack to article page