In 1994, leading researchers at CSIRO Peter Lust and John Stevens officially recognized the undescribed species of the genus of big-headed sharks, which has a colorful color, giving it the name Cephaloscyllium “sp. E. " Recent studies have shown that in fact under the guise of Cephaloscyllium "sp. E. ” implied Cephaloscyllium speccum and Cephaloscyllium signourum , described in 2008 in the publication CSIRO [1] . The specific name signourum comes from the words lat. signum , which means “flag” and Greek. ουρά is the “tail” and refers to specific marks on the tail of this shark. A typical specimen was a female 74 cm long, caught in the Lihou Reef and Cays National Reserve, near Queensland [1] .
Cephaloscyllium signourum is found off the coast of Marray Island and Lihou Ree in northeast Queensland, New Caledonia , Vanuatu and Fiji . This bottom shark lives at a depth of 480-700 m [1] .
It reaches a length of at least 74 cm, a maximum length of 1 m. This is a shark with a strong body and a short, wide and strongly flattened head. The face is rounded. The nostrils are surrounded by folds of skin that do not reach the mouth. Slit-like eyes are high. The mouth is short and wide; there are no furrows in the corners. There are 84 upper and 97 lower dentitions in the mouth. Upper teeth are visible even when the mouth is closed. The fourth and fifth gill slots are located above the pectoral fins and shorter than the first three [1] .
The narrow tip of the first dorsal fin is rounded. The first dorsal fin is larger and higher than the second. Its base lies behind the anterior half of the base of the ventral fins. The pectoral fins are large and wide, slightly pointed. The second dorsal fin begins in front of the base of the anal fin. The anal fin is much larger than the second dorsal fin. The wide caudal fin has a well-developed lower lobe and a deep ventral notch at the tip of the upper lobe. The ventral fins are small. The skin is thick, covered with numerous, overlapping, placoid scales with one tooth. The color is brown, 9-10 dark spots of a saddle shape are scattered on the back, there are dark marks on the fins, there is a characteristic V-shaped mark on the upper tip of the caudal fin. The belly is solid white. The back of young yellow sharks with transverse dark stripes, which with age turn into saddle spots. A pair of loops behind the eyes join to form a curved line [1] [2] .
Like other big-headed sharks, Australian big-headed sharks are able to inflate with water or air, being pulled out of the water, and swell in case of danger; in this way they wedge in the cracks, not allowing themselves to be caught, and even scare away the predator [2] .
In the habitats of Cephaloscyllium signourum, intensive deep-sea fishing is not conducted. This species in itself is rare. Data to assess the state of conservation is not enough [3] .
