The elasmobranch spiracular organ - I. Morphological studies

Michael A. Barry, David H. Hall, Michael V.L. Bennett

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


The spiracular organ is a lateral line derived receptor associated with the first gill cleft (spiracle). Its functional morphology was studied in the little skate, Raja erinacea, and a shark, the smooth dogfish, Mustelus canis, with light and electron microscopy. The spiracular organ is a tube (skate) or pouch (shark) with a single pore opening into the spiracle. The lumen is lined with patches of sensory hair cells, and filled with a gelatinous cupula. In the little skate, hair cells form synapses with afferents but apparently not with efferent fibers. In both species, the spiracular organs are deformed by flexion of the hyomandibular cartilage at its articulation with the cranium. The hyomandibula is a suspensory element of the jaws; hyomandibular flexion results in jaw protrusion. The little skate spiracular organ is anchored at one end to the cranium and at the other to the hyomandibula so that it is stretched or relaxed during hyomandibular extension and flexion, respectively. In Mustelus, the effects of hyomandibular flexion on the spiracular organ are mediated indirectly by the superior post-spiracular ligament which inserts on the distal end of the hyomandibula. Deformation of the dogfish shark cupula during hyomandibular movement was observed. In the little skate, as revealed by transmission electron microscopy, there is a measurable deflection of the hair cell ciliary bundles from spiracular organs fixed with the hyomandibula in the flexed relative to the extended positions. In both species, hyomandibula flexion should result in hair cell depolarization, and sensory afferent excitation, based on the direction of the observed (skate) or expected (shark) deflection of hair cell cilia.

Original languageEnglish (US)
Pages (from-to)85-92
Number of pages8
JournalJournal of Comparative Physiology A
Issue number1
StatePublished - Jan 1988

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Physiology
  • Animal Science and Zoology
  • Behavioral Neuroscience


Dive into the research topics of 'The elasmobranch spiracular organ - I. Morphological studies'. Together they form a unique fingerprint.

Cite this