This week’s Featured Species is just so frickin’ cute! The California Horn Shark (Heterodontus francisci) is a relatively small shark, reaching an average of 3.5 feet (1.06 m) in length. Like other bullhead sharks in Heterodontidae, they have broad eye ridges on blunt heads and pig-like snouts. They also sport two spines in front of their two dorsal fins.
The dorsal spines go a long way to protect the horn shark from potential predators. Not only are they incredibly sharp, but they are also mildly venomous (Parker, 2008). I definitely wouldn’t want to eat something that both stabbed me in the mouth or throat and was venomous!
Discovery Shark Week. (Videographer). (n.d.). Horn Shark Vs Angel Shark [Video Clip]. Retrieved from http://i.imgur.com/
There are 9 species of bullhead, horn, and port jackson sharks within Heterodontidae. Fossil evidence suggests that these extant shark species closely resemble an extinct species from 220 million years ago (Parker, 2008). Heterodontidae sharks are considered a primitive shark morphology (Parker, 2008). That is to say that while they are modern sharks, their form resembles that of early prehistoric sharks.
The horn shark, like other members of Heterodontidae, have different teeth morphologies throughout the jaw. In the front of the jaw, horn sharks have small, sharp teeth that grab onto their prey. While the back of the jaw has large, moral, pavement-like teeth that crush their hard-bodied prey, like crustaceans. The name Heterodontidae is taken from the Greek meaning “different teeth” (Tricas, et al., 1997; Parker, 2008).
The horn shark is known to rest on the bottom kelp beds and rocky boulders during the day, sometimes huddling together with other horn sharks and even the occasional swell shark (Cephaloscyllium ventriosum). At night, these sharks seek out their crunchy prey, snacking on crustaceans, bivalves, and other invertebrates (Skomal, 2016).
California horn sharks are oviparous, which means they lay eggs. Females lay corkscrew-like eggs which they wedge into rocky ledges and kelp beds. That is the extent of the parental care the young will receive. After 6 to 10 months, depending on the water temperature, the young sharks hatch (Tricas, et al., 1997).
Authority: Girard, 1855
Family: Heterodontidae, 9 species
Length: Small, less than 3 feet (1 m)
Weight: Up to 22 lbs (10 kg)
Habitat: Continental shelves, coastal waters, coral reefs, rocky areas, kelp beds
Depth: Benthic species; typically found 25 – 40 feet (7.6 – 12.2 m), occasionally found in intertidal zone up to 656 feet (200 m)
Gestation: Eggs hatch in 6 – 10 months
Litter Range: Females lay up to 24 eggs every 11 – 14 days February to April
Home Range: Patchy tropical and temperate waters of the Pacific
Diet: Bottom invertebrates
IUCN Status: Data Deficient
(Carlisle, 2015; Parker, 2008; Skomal, 2016)
If you missed last week’s Featured Species, be sure to check out the Grey Reef Shark! If you have any species you’d like to see featured here, leave me a comment and let me know!
The new Ocean For Sharks Shop is open! There’s handmade ocean inspired plush animals, canvas paintings, and of course my children’s book, Winifred the Wondrous Whale Shark, available in print and PDF. Be sure to stop by. Remember proceeds benefit shark research and conservation with a donation to Project AWARE!
Remember you can make a difference for marine ecosystems by calling your Congress man or woman and tell them that you care about the quality of our waters! Sharks, rays, and other marine organisms cannot speak or be represented in Congress. They need your voice. Get involved and stand up for sharks. Until next time finatics.
Featured Image Source
O’Connell, B. (Photographer). (2017 January 8). California Horn Shark [Digital Image]. Retrieved from https://www.quora.com/
Carlisle, A.B. 2015. Heterodontus francisci. The IUCN Red List of Threatened Species 2015: e.T39333A80671300.
Parker, S. (2008). The encyclopedia of sharks (2nd ed.). Buffalo, NY: Firefly Books Ltd.
Skomal, G. (2016). The Shark Handbook: The Essential Guide for Understanding the Sharks of the World. (2nd ed.). Kennebunkport, ME: Cider Mill Press.
Tricas, T. C., Deacon, K., Last, P., McCosker, J. E., Walker, T. I., & Taylor, L. (1997). The Nature Company Guides: Sharks and Rays. (L. Taylor, Ed.). Hong Kong: The Nature Company, Time Life Books.