The Banded houndshark (Triakis scyllium) is a species of shark belonging to the family Triakidae. They are common in northwest Pacific in southern Siberia, Japan, China (including Taiwan), and the Koreas. These sharks can be found inshore, on or near the bottom. They do seem to prefer sea grass beds and are known to enter brackish estuaries. This shark has dark saddles and spots which typically fade with age.
Family: Triakidae – Houndsharks
Genus: Triakis
Species: scyllium
Phylum– Chordata
Class– Chondrichthyles
Common Name– Ground Sharks
Family– Triakidae
Common Name– Houndsharks
Genus– Triakis
Species– scyllium
Status: IUCN Red List LEAST CONCERN
Average Size and Length: Newborns measure 18–20 cm/7-7.8 inches. Mature males measure between 99-108 cm/3.2-3.5 feet. The maximum recorded is at least 150 cm/4.9 feet.
Current Rare Mythical Sightings: The first scientific description of the Banded houndshark was authored by German biologists Johannes Peter Müller and Friedrich Gustav Jakob Henle, based on a dried specimen from Japan, in their 1838–41 Systematische Beschreibung der Plagiostomen. They gave it the specific epithet scyllium, derived from the Ancient Greek skylion (“dogfish”), and placed it in the genus Triakis (Müller, J. & F.G.J. Henle (1838–41). Systematische Beschreibung der Plagiostomen. Veit und Comp. pp. 63–64).
Teeth and Jaw: The mouth forms a short, wide arch that has long furrows at the corners that extend onto both jaws. The teeth are partly blade like. Each tooth has an upright to oblique knife-like central cusp flanked by strong cusplets.
Head: The snout is short and broadly rounded. The widely separated nostrils are each preceded by a lobe of skin that does not reach the mouth. The horizontally oval eyes are placed high on the head and have nictitating membranes. There are ridges underneath the eyes.
Tail: The caudal fin has a well-developed lower lobe and a prominent ventral notch near the tip of the upper lobe. In young sharks the lower caudal fin lobe is much less distinct.
Demographic, Distribution, Habitat, Environment and Range: The Banded houndshark can be found in the northwest Pacific in southern Siberia, Japan, China (including Taiwan), and the Koreas (48°N – 20°N). They can be found on the continental and insular shelves, close inshore, on or near the bottom. They are often found in brackish estuaries and in shallow bays, on sand, seaweed and eel-grass flats. It is considered subtropical demersal.
Diet: They feed on crustaceans, cephalopods, small fish and invertebrates. Shrimp and spoon worms are important prey for smaller sharks, and larger sharks consume a majority of cephalopods.
Aesthetic Identification: The Banded houndshark is a somewhat slender shark grey dorsally, with lightly scattered small black spots and broad saddles in young sharks that are dusky in color. The saddles and spots sometimes fade or are absent in adult sharks. The ventral side is lighter. The fins are relatively narrow. The pectoral fins are triangular in adult sharks. The first dorsal fin rear margin is almost vertical and tall, and placed about halfway between the pectoral and pelvic fins. The second dorsal fin is about three-quarters as high as the first and larger than the anal fin.
Biology and Reproduction: They are ovoviviparous, without a yolk-sac placenta. They have anywhere from 10-20 pups per litter. There are some accounts of sharks having as many as 42 pups per litter. Gestation lasts anywhere from 9-12 months. Mating is thought to occur during summer.
Males mature sexually at 93–106 cm/3-3.4 feet, or 5–6 years old and live up to 15 years of age. Females mature at 106–107 cm/3.4-3.5 feet, or 6-7 years and live up to 18 years.
Known parasites of this species include the tapeworms Callitetrarhynchus gracilis, Onchobothrium triacis, and Phyllobothrium serratum, the leech Stibarobdella macrothela, and the copepods Achtheinus impenderus, Caligus punctatus, Kroyeria triakos, and Pseudopandarus scyllii.
Behavioral Traits, Sensing and Intelligence: They are very rarely sociable, but will assemble together in selected seabed resting areas and on occasion in caves or crevices. This shark is also mostly nocturnal.
Banded Houndshark Future and Conservation: They are of least concern. They are abundant and common among their range. They are fished and often caught as bycatch in Taiwan and Japan, and more than likely in other parts of its range. This shark is often displayed in public aquariums in Japan and China, including a captive reproduction. These sharks have been recorded to typically live up to 5 years.
Banded Houndshark Recorded Attacks on Humans: Not a threat to humans.