DWARF SAWTAIL CATSHARK
A rare and tiny catshark that inhabits Luzon
The Dwarf Sawtail catshark (Galeus schultzi) is a little-known species of catshark belonging to the family Scyliorhinidae. They are found in deep water off of Luzon in the Philippines. They are one of the smallest species of catshark, and have a uniquely short, rounded snout and short furrows at the corners of the mouth.
Family: Scyliorhinidae – Catsharks
Common Name– Ground Sharks
Common Name– Catsharks
Status: IUCN Red List DATA DEFICIENT
Average Size and Length: Mature males have been measured at 25 cm/9.8 inches. Mature females have been measured between 27-30 cm/10.6-11.8 inches. The maximum recorded has been 30 cm/11.8 inches.
Current Rare Mythical Sightings: Stewart Springer described the Dwarf Sawtail catshark in a 1979 National Oceanic and Atmospheric Administration (NOAA) Technical Report. The type specimen is an adult male 30 cm/12 inches long, collected from Balayan Bay. Since it doesn’t resemble other members of its genus, we may find that this shark may be moved in the future.
Teeth and Jaw: There are also very short labial furrows that are confined to the mouth corners. The mouth lining is dusky or light. The mouth is relatively large and wide. There are 48 tooth rows in the upper jaw, and fewer in the lower jaw; each tooth has a narrow central cusp flanked by lateral cusplets.
Head: The snout is short and rounded, which is unusual for a sawtail catshark. The nostrils are divided by triangular flaps of skin on their anterior rims. The horizontally oval eyes are placed somewhat high on the head, and have nictitating membranes. There are low ridges beneath the eyes, and tiny spiracles behind them.
Denticles: There is a distinct crest of dermal denticles along the upper margin of the tail, but not along the bottom or lower margin. The small, overlapping dermal denticles each have a leaf-shaped crown with a median ridge and three teeth on the posterior margin.
Tail: The tail is elongated. The caudal peduncle is nearly cylindrical and leads to a low caudal fin with an indistinct lower lobe and a ventral notch near the tip of the upper lobe.
Demographic, Distribution, Habitat, Environment and Range: The Dwarf Sawtail catshark can be found in the western Pacific. They are endemic in the Philippines off of Luzon (20°N – 5°N, 116°E – 128°E). They are mainly on the insular slopes between 1,079-1,414 feet. There is one record of one being on the outer shelf at 50 m. They are a bathydemersal, deep-water species.
Aesthetic Identification: The Dwarf Sawtail catshark is one of the smallest catsharks. It is a slender shape and has 5 gill slits. There is a pattern of obscure dark saddle blotches below the dorsal fins and two bands on the tail. There are no black tips to the dorsal and caudal fin tips. The two dorsal fins have rounded apexes and are similar in size. The first dorsal fin originates over the aft portion of the pelvic fins, and the second over the aft portion of the anal fin. The pectoral fins are relatively large and wide. The pelvic and anal fins are short and low, with angular corners. The base of the anal fin measures 10–11% of the total length, longer than the distances between either the dorsal fins or the pelvic and anal fins.
Biology and Reproduction: Unknown, but possibly oviparous.
Behavioral Traits, Sensing and Intelligence: Not much is known.
Dwarf Sawtail Catshark Future and Conservation: There is not enough data to evaluate.
Dwarf Sawtail Catshark Recorded Attacks on Humans: Not a threat to humans.