Hornsharks are called such for the two prominent dorsal spines that occur one each in front of their twin top fins (the only shark family with these anal fins). They are also known as Pig and  Bullhead Sharks for their appearance as well as Port Jackson's for the area of their original collection. The family of Hornsharks, Heterodontidae has but one genus and this monotypic genus, eight species. The roots of the family name may seem familiar: "hetero" meaning dissimilar, and "don't" referring to teeth... alluding to these fishes possession of two different types of dentition; incisor like "shark" teeth for biting off pieces, and crushing "molar" plates for breaking the hard shells of marine organisms for food, much the same as Bat rays.

    The heterodontids are all cool to semi to sub-tropical species, rarely occurring in water more than in the 60's F.. In the aquarium interest most often you'll find the Californian H. francisci and to a smaller extent (and almost only outside the U.S.) the southern Australian H. portusjacksoni, though there is a slightly more tropical and gorgeous Heterodontus zebra, it is rarely offered out of the Western Pacific.

Challenges to Hornshark Keeping:

    These are the same as with all sharks, the space needed to adequately house them, need for clean, nutrient-free water... compounded with the fact that these are decidedly coldwater organisms, almost-always requiring a chilled system.

    To their advantage, Hornsharks are mostly sedentary animals, maybe swimming about a few percent of the time, reducing greatly the need for larger quarters, greater aeration/circulation and filtration.

Systems:

    As this is an oviparous shark species, one can buy their "purse" like eggs and hatch out quite small young to start with... and "grow their own"... But be aware that this is a fast growing species for such a small shark and that yours may easily be in the teens of inches within a year of birth. As adults they should not be kept in a container of less than eight by six feet... rounded corners, or even oval to round tanks are a plus, even with these lay-about animals. Also, though they appear incapable, this (and all other sharks) are very capable of launching themselves out of a tank or pool... keep yours well covered.

    Keeping the system as metabolite-free is important. Higher nitrates are a good indicator here... An efficient over-sized skimmer like the Euro-Reef or ETSS lines are called for, as well as mechanisms of capacity for denitration (e.g. DSB's, Refugiums...), as well as careful feeding and regular maintenance.

    Decor should include enough space for your Hornsharks to "lay out", as well as at least one good sized cave or overhang per specimen. These are social animals, but they do like to get out of the light at times, particularly during the night. Make sure and either anchor the rock/decor together or stack directly on the bottom to start, steadily pile on top of each piece to assure it will not move with these fish digging about.

Tankmates:

    Other cool to coldwater fishes from the same geographic distribution are best. Smaller fishes, motile, sessile invertebrates like clams, crustaceans are likely to become meals over time.

Heterodontus francisci (Girard 1855), the Horn Shark. Eastern Pacific, usually collected off California (USA) coast. To nearly four feet in length. A cool/cold water species unsuitable for tropical temperatures. Public Aquarium specimens shown.

8" juv.

    Most Hornsharks offered come in very good shape, the few folks that collect them being professionals in California, however, you should make careful inspection of prospective purchases for signs of damage (tears in fins, bloody markings) and be assured (by demonstration) that the animal/s are indeed feeding.

    Do wait at least a couple of days after arrival (or with grace from a distal supplier) to allow these sharks to "rest up"... the few that are lost due to collection, handling from the wild generally perish from such within the first 48 hours of arrival.

    The possibility of buying unhatched eggs has been mentioned. This can be a really neat experience if one has patience... can and will wait (no help necessary) for the young to develop, work their way out of their screw-shaped egg cases.

Foods/Feeding/Nutrition:

    There is literally little of meaty food items of size that heterodontids won't ingest. Shellfish (littleneck clams, cockles...), squid (cleaned), fish flesh, shrimps, crabs... even urchins and anemones are all taken with gusto once the animal is familiar with them. Initially, offering food items with a "stick" down near the head of uninitiated specimens may be called for. Once associated with them, these sharks will often approach the surface with the approach of the aquarist.

Conclusion:

    The Hornsharks are likely the most appropriate family of cool water selachians for aquarium use... starting small, staying relatively inactive, accepting most foods... Though still requiring good-sized quarters, adequate cooling, circulation, aeration, filtration...

    Starting with an unhatched eggs especially, one can enjoy these dual-toothed sharks for several years given care to providing decent husbandry. Records of longevity in captivity exceed 25 years.

Bibliography:

Sharks and Rays in Aquariums Gaining an understanding of how to keep these fishes in captive saltwater systems    New Print and eBook on Amazon: Available here  by Robert (Bob) Fenner