Horn Sharks, Heterodontus francisci
Taxonomy
Animalia Chordata Elasmobranchii Heterodontiformes Heterodontidae Heterodontus francisci
Description & Behavior
Horn sharks, Heterodontus francisci (Girard, 1855), aka California horn sharks, have short, blunt heads with high ridges above their eyes and large fin spines, including 2 prominent dorsal fin spines, hence their name. They are small and quite beautiful sharks reaching about 1.22 m in length. These sharks are a sluggish, solitary species with broad, strong fins used to maneuver over the ocean bottom in search of prey.
Galapagos horn sharks, Heterodontus quoyi, inhabit the waters of the Galapagos Islands and other islands off Peru. Growing to a length of 0.57 m, they are also most active at night and feed heavily on crabs. This species is often observed resting on ledges of vertical rock faces at depths of 15-30 m. Despite their defensive dorsal spines, one small specimen was found in the stomach of a tiger shark.
World Range & Habitat
Horn sharks, Heterodontus francisci, are found in subtropical waters between 37°N - 22°N, 124°W - 75°W including: the eastern Pacific in central California, USA to the Gulf of California, and likely south to Ecuador and Peru.
Horn sharks prefer rocky bottoms, kelp beds, sand flats, deep crevices and small caves, and underwater caverns. Adults tend to maintain the same resting places day to day.
Feeding Behavior (Ecology)
Horn sharks feed mainly on small fishes and invertebrates such as mollusks, sea urchins, and crabs. They are nocturnal animals coming out from under ledges and rocks at night to feed.
Life History
Horn sharks, Heterodontus francisci, are oviparous, meaning females release eggs with a yolk sac attached. Horn sharks mate in the months of December and January. "The male horn shark chases the female until the latter is ready, then both drop to the (ocean) bottom. The male grabs the female's pectoral fin with his teeth and inserts a single clasper in her cloaca; copulation lasts 30 to 40 minutes." A few weeks after copulation, the female will deposit the fertilized eggs in cases amongst the rocks where they will hatch anywhere from 6-9 months later. The young sharks, when first born, are roughly 15-17 cm in length.
Conservation Status & Comments
Latest Conservation Status of Horn Sharks Check the Seafood Watch List for this species
Horn sharks may bite fingers when harassed and their large fin spines can cause nasty puncture wounds. The most important value of Heterodontus francisci comes from research. Scientists have studied these sharks in captivity where they have been known to survive for up to 12 years. This is important because most sharks die shortly after they are placed into captivity, most often because they stop eating. Therefore, horn sharks prove to be quite valuable to scientists wishing to study sharks. Although there is no commercial market for horn sharks, except for the aquarium trade, some are taken occasionally by fishers, usually in crab traps or in gillnets and trawls as bycatch.
References & Further Research
Order Heterodontiformes: Bullhead Sharks - 10 species
[ Photography ] Horn Shark Photographs - Golden State Images, Randy Morse
Castro, J. 1983. The Sharks of North American Waters. Texas A&M University: Texas A&M University Press.
Compagno, L. 1984. Sharks of the World. Rome: United Nations Developement Programme.
Research Heterodontus francisci » Barcode of Life ~ BioOne ~ Biodiversity Heritage Library ~ CITES ~ Cornell Macaulay Library [audio / video] ~ Encyclopedia of Life (EOL) ~ ESA Online Journals ~ FishBase ~ Florida Museum of Natural History Ichthyology Department ~ GBIF ~ Google Scholar ~ ITIS ~ IUCN RedList (Threatened Status) ~ Marine Species Identification Portal ~ NCBI (PubMed, GenBank, etc.) ~ Ocean Biogeographic Information System ~ PLOS ~ SCIRIS ~ SIRIS ~ Tree of Life Web Project ~ UNEP-WCMC Species Database ~ WoRMS
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