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Family Heterdontidae
Horn and Bullhead Sharks
Tiffany Adams
September 25, 2007
Elasmobiology
Taxonomy
Order: Heterodontiformes
Family: Heterodontidae
1 Genus, 8 species
 Heterodontus francisci- Horn shark
 Heterodontus galeatus- Crested bullhead shark
 Heterodontus japonicus- Japanese bullhead shark
 Heterodontus mexicanus- Mexican hornshark
 Heterodontus portusjacksoni- Port Jackson Shark
 Heterodontus quoyi- Galapagos bullhead shark
 Heterodontus ramalheira- Whitespotted bullhead shark
 Heterodontus zebra- Zebra bullhead shark
Heterodont- “different teeth”
Distinctive Characteristics:
 Small in size <165cm
 Five gill slits
 Anal fin present
 No nictating eyelid
 Small spiracle present
 Two dorsal fins with stout spines- hypothesized to act as an anti-predator device
 Proportionally large pectoral fins- thought to be used for “walking” across bottom
 Prominent supra-orbital crest/ridge above each eye
 Short, blunt snout
 Nostrils connected to mouth with deep nasal groove
 Differentiated anterior and posterior teeth
o anterior teeth small and multicuspid, used for grasping prey
o posterior teeth are enlarged, elongated and molariform, used for crushing shells
Habitat and Global Distribution:
 Benthic, prefer to live near rocks, reefs, caves, and kelp beds in shallow coastal waters.
 Found in warm-temperate and tropical continental waters of the western Indian Ocean
and western and eastern Pacific; absent from the Atlantic and Mediterranean.
Prey
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Nocturnal feeders, mostly benthic invertebrates
Short snout allows them to protrude lower jaw and use suction feeding
Diet includes sea urchins and anemones, mollusks, crustaceans, worms, and small fish.
Regurgitate shells and hard parts.
Reproduction
 Age of maturity estimated between 8-10 years, but not known
 Oviparous, egg cases contain yolk sac
 Two eggs can simultaneously mature within each female, they may lay up to 24 eggs
total in a breeding season.
 Spiral-flanged egg cases, conical, some with tendrils. Up to 15cm in length.
 Expulsion can take up to 2 hours. Soft egg case is carried by mother in her mouth and
secured in rocky substrate. Communal nests may contain over 16 egg cases.
 Young will emerge in 6-10 months, depending on species.
 Some species, such at the Port Jackson shark, undergo a yearly migration for spawning.
Population Status
 Not targeted by fisheries, bycatch only. May be used for fishmeal.
 IUCN lists all at data deficient or least concern.
Bibliography
 Allen, T. 1999. Shark Almanac. Lyons Press, New York. Pp. 62-3.
 Carrier, J,, Musick, J., and Heithaus, M. 2004. Biology of Sharks and Their Relatives.
CRC Press, Boca Raton. Pp. 42-3, 66-7, 401.
 Compagno, L.J.V., 1984. FAO species catalogue. Vol. 4. Sharks of the world. An
annotated and illustrated catalogue of shark species known to date. Part 1 Hexanchiformes to Lamniformes. FAO Fish. Synop. 125(4/1):1-249.
 Edmonds, M. et al. 2001 Food capture kinematics of the suction feeding horn shark,
Heterodontus francisci. Journal Environmental Biology of Fishes. 62(4):415-427
 Huber, D. et al. 2005. Analysis of the bite force and mechanical design of the feeding
mechanism of the durophagous horn shark Heterodontus francisci. The Journal of
Experimental Biology. 208(18):3553-71
 IUCN 2006. 2006 IUCN Red List of Threatened Species. <http://www.iucnredlist.org>.
Downloaded on 20 September 2007.
 Jones,W.T. 2005. A hermaphroditic Port Jackson shark, Heterodontus portusjacksoni,
with complete and separate female and male reproductive tracts. Journal of the Marine
Biological Association of the UK. 85:1171-1172
 Nelson, J. 1984. Fishes of the World. 2nd Ed. John Wiley & Sons, Inc., New York. P. 50.
 O'Gower, A.K. 1995. Speculations on a spatial memory for the Port Jackson shark
(Heterodontus portusjacksoni). Marine & Freshwater Research. 46(5):861-871.
 Parker, S. 1999. The Encyclopedia of Sharks. Firefly Books, Buffalo. Pp. 50, 130, 174-5.
 Perrine, D. 1999. Sharks and Rays of the World. Voyageur Press, Hong Kong. Pp. 82-5.
 Steel, R. 1985. Sharks of the World. Facts on File, Inc., New York. Pp. 42-43, 77-81.