Vertebral gap This picture of a cleared and stained specimen of the dragonfish Chauliodus sloani shows bones in red and cartilage in blue. Clearly visible is a gap of seven missing “vertebral centra” (NA2-7) between the rear of the fish's skull and its first fully ossified vertebrae (C8). The bones above and below the centra (Na1-7; Papo 2-7) ossify. The flexible notochord persists in this region (despite being stained bluish, the notochord is not made of cartilage). C = centrum; NA = neural arch; Papo = parapophysis; Sn = supraneural. Photo by Ralf Britz of The Natural History Museum, London.

Barbeled dragonfishes Barbeled dragonfishes, like those pictured here, belong to the family Stomiidae, which also includes the stareaters and loosejaws. These are all deep-sea fishes with elongated bodies. The largest dragonfish species are about 16 inches long, though most are only half that size. Most species are bioluminescent, with numerous "photophores" along the body. They are predators with large, fang-like teeth. Photo by Nalani Schnell.

Barbeled dragonfishes Schnell's study of the muscle segments and nerves surrounding the "occipito-vertebral gap" in a specimen of the dragonfish Malacosteus niger shows that the gap in this species is formed by a lengthening of the notochord (Nch) rather than a loss of any vertebrae. C1 = centrum of first vertebrae; Oc = occiput (the rear of the skull). The specimen is from the Smithsonian's National Museum of Natural History in Washington, D.C. Photo by Nalani Schnell.

VIMS Larval Fish Collection VIMS post-doctoral fellow Nalani Schnell and professor Eric Hilton examine specimens from the larval fish collection at VIMS. Photo by Susan Stein.