Title: Crested bullhead shark
Content:  The head of the crested bullhead shark is short and wide, with a blunt, pig-like snout. The eyes are placed high on the head and lack nictitating membranes. The supraorbital ridges above the eyes of this species are larger than any other member of its family. The nostrils are separated into incurrent and excurrent openings by a long flap of skin that reaches the mouth. A furrow encircles the incurrent opening and another furrow runs from the excurrent opening to the mouth, which is located nearly at the tip of the snout. The teeth at the front of the jaws are small and pointed with a central cusp and two lateral cusplets, while those at the back of the jaws are wide and molar-like. The deep furrows at the corners of the mouth extend onto both jaws. The pectoral fins 
Title: Bullhead shark
Content:   The bullhead sharks are morphologically rather distinctive. The mouth is located entirely anterior to the orbits. Labial cartilages are found in the most anterior part of the mouth. Nasoral grooves are present, connecting the external nares to the mouth. The nasal capsules are trumpet-shaped and well-separated from orbits. Circumnarial skin folds are present, but the rostral process of the neurocranium (braincase) is absent, although a precerebral fossa is present. Finally, the braincase bears a supraorbital crest. The eyes lack a nictitating membrane. A spiracle is present, but small. The dorsal ends of the fourth and fifth branchial arches are attached, but not fused into a "pickaxe" as in lamniform sharks. Heterodontiforms have two dorsal fins, with fin spines, as well as an anal fin. The dorsal and anal fins also contain basal cartilages, not just fin rays.
Title: Crested bullhead shark
Content:  large and rounded, while the pelvic and anal fins are smaller and more angular. The first dorsal fin is moderately tall with a rounded to angular apex and a stout spine on the leading margin, originating behind the pectoral fins. The second dorsal fin resembles the first and is almost as large, and is located between the pelvic and anal fins. The caudal fin is broad, with a strong ventral notch near the tip of the upper lobe. The dermal denticles are large and rough, especially on the flanks. The coloration consists of five brown to black, diffusely edged saddles on a light tan background. There are dark marks on top of the head between the crests and below each eye. Most crested bullhead sharks measure no more than 1.2 m long, but a few may reach 1.5 m.
Title: Japanese bullhead shark
Content:  their leading edges. The pectoral fins are large; the pelvic fins are much smaller than the first dorsal fin. The anal fin is placed well in front of the caudal fin, which is broad with a short lower lobe and a long upper lobe bearing a strong ventral notch near the tip. The dermal denticles are large and rough, particularly on the sides of the body. The coloration is light brown, with a series of diffuse-edged, darker wide bands interspersed with narrower stripes from snout to tail, numbering 11&ndash;14 in all. A faint lighter band is on top of the head between the eyes, and a darker blotch is beneath each eye.
Title: Bull shark
Content:  The bull shark's diet consists mainly of bony fish and small sharks, including other bull sharks, and stingrays. Their diet can also include turtles, birds, dolphins, terrestrial mammals, crustaceans, and echinoderms. They hunt in murky waters where it is harder for the prey to see the shark coming. Bull sharks have been known to use the bump-and-bite technique to attack their prey. After the first initial contact, they continue to bite and tackle prey until the prey is unable to flee. The bull shark is a solitary hunter, though may briefly pair with another bull shark to make hunting and tricking prey easier. Sharks are opportunistic feeders, and the bull shark is no exception to this, as it is part of the Carcharhinus family of sharks. Normally, sharks eat in short bursts, and when food is scarce, sharks digest for a much longer period of time in order to avoid starvation. As part of their survival mechanism, bull sharks will regurgitate the food in their stomachs in order to escape from a predator. This is a distraction tactic; if the predator moves to eat the regurgitated food the bull shark can use the opportunity to escape.
Title: Japanese bullhead shark
Content:  A modest-sized shark reaching a maximum known length of 1.2 m, the Japanese bullhead shark has a cylindrical body with the short, wide head and blunt, pig-like snout typical of the bullhead sharks. The eyes lack a nictitating membrane and are followed by tiny spiracles. Shallow supraorbital ridges are present above the eyes, and the space between them is slightly concave. The nostrils are divided into incurrent and excurrent openings by long flaps of skin that reach the mouth; the incurrent opening is encircled by a groove while another groove runs from the excurrent opening to the mouth. The small mouth is positioned nearly at the tip of the snout; the front teeth 
Title: Crested bullhead shark
Content:  The crested bullhead shark is a slow-moving, nocturnal species often seen wedging its head between rocks in search of food. It feeds primarily on the sea urchins Centrostephanus rodgersii and Heliocidaris erythrogramma, but has also been known to take a variety of other invertebrates and small fishes. A steady diet of sea urchins may stain the teeth of this shark pinkish purple. The crested bullhead shark is also a major predator of the eggs of the Port Jackson shark, which are seasonally available and rich in nutrients. Individual sharks have been observed taking the egg capsules in their mouths and chewing on the tough casing, rupturing it and allowing the contents to be sucked out; 
Title: Smoothtooth blacktip shark
Content:  Superficially, the smoothtooth blacktip shark resembles the blacktip reef shark (C. melanopterus). It is rather robust in build, with a short and blunt snout. The large nostrils are preceded by well-developed, triangular flaps of skin. The small, circular eyes are equipped with nictitating membranes. The mouth forms a wide arch and has very short furrows at the corners. Sixteen upper and 14–15 lower tooth rows are on either side, along with two or three small teeth at the symphysis (center) of either jaw. The teeth are distinctive in shape, having narrow, upright cusps without serrations; finetooth sharks and juvenile spinner sharks are the only other members of 
Title: Shark tooth
Content:  This was the first common style of shark tooth, present in the Devonian, four hundred million years ago. Sharks with needle-like teeth commonly feed on small to medium-sized fish, sometimes including small sharks. These teeth are especially effective for such prey because they can easily grip their slippery and narrow bodies. Modern examples include the blue shark and bull sharks. These sharks specifically use their teeth to feed on small prey like squid, flounder, stingrays, and even hammerhead sharks.
Title: Japanese bullhead shark
Content:  small with a sharp central cusp flanked by a pair of lateral cusplets, while the back teeth are broad and rounded. There are deep furrows at the corners of the mouth, extending onto both jaws. Despite the research done, the morphology is not well understood. A recent research shows that the spiracle of elasmobranchs is a gill-slitderived tube located behind the eye. The first dorsal fin is very large and high, and is somewhat falcate (sickle-shaped); it originates over the bases of the pectoral fins. The second dorsal fin is much smaller, but similar in shape, and originates over the rear tips of the pelvic fins. Both dorsal fins bear stout spines 

Question: what does a bull shark tooth look like?
Answer: needle-like teeth.
needle-like.