A schooling shallow-water shark with a spade snout
The Spadenose shark (Scoliodon laticaudus) is a species of requiem shark in the family Carcharhinidae. It is common in the tropical Indian and western Pacific Oceans, where it forms large schools in shallow water. The Spadenose shark has the most advanced form of placental viviparity known in fish.
Family: Carcharhinidae – Requiem sharks
Common Name– Ground Sharks
Common Name– Requiem Sharks
Status: IUCN Red List NEAR THREATENED
Average Size and Length: The maximum known length of the Spadenose shark is 29 inches. There are some reports of a Spadenose shark reaching 3.9 feet.
Teeth and Jaw: The corners of the mouth are well behind the eyes and have poorly developed furrows at the corners. About 25–33 tooth rows are in the upper jaw and 24–34 tooth rows are in the lower jaw; each tooth has a single slender, blade-like, oblique cusp without serrations.
Head: The Spadenose shark has a broad head with a flattened trowel-shaped snout with small nares and eyes.
Demographic, Distribution, Habitat, Environment and Range: The Spadenose shark is found in the western Indo-Pacific from Tanzania to South and Southeast Asia, as far east as Java and Borneo and as far north as Taiwan and Japan. It is typically found close to the coast in water 33–43 feet deep. It is typically close to rocky bottoms. It is frequently reported from the lower reaches of rivers in Malaysia, Sumatra, and Borneo, though whether this species can tolerate fresh water. Scientists are still unsure of the degree of salinity toleration, for no data has been collected in the area.
Diet: The Spadenose shark mainly eats small bony fishes like anchovies, codlets, burrowing gobies, and Bombay ducks. Shrimp, crabs, cuttlefish, and stomatopods are also sometimes eaten.
Aesthetic Identification: The Spadenose shark is small and stalky. The upper side of the shark is bronze-gray in color, and the belly is counter-shaded white. The fins are plain but may be darker than the body. The first dorsal fin is positioned closer to the pelvic than the pectoral fins, which are very short and broad. The second dorsal fin is much smaller than the anal fin. No ridge occurs between the dorsal fins.
Biology and Reproduction: Known parasites of the Spadenose shark include the tapeworm Ruhnkecestus latipi, and the larvae of ascaridid roundworms.
The Spadenose shark is viviparous and has the most advanced form of placental viviparity known in fish, as measured by the complexity of the placental connection and the difference in weight between the egg and the newborn young.
Female Spadenose sharks probably mate at least once per year, and breeding takes place year-round. The gestation period of the Spadenose shark is between 5-6 months long, and the young are born at a length of 4.7–5.9 inches. The litter size ranges from 6 to 18 pups.
Males mature sexually at a length of 9.4–14.2 inches, and females at a length of 13–14 inches. Estimates of the age at maturity range from 6 months to 2 years. The lifespan may be 5 years for males and 6 years for females.
Behavioral Traits, Sensing and Intelligence: Abundant in many areas, Spadenose sharks often form large schools.
Spadenose Shark Future and Conservation: The Spadenose shark is taken by artisanal and commercial fisheries across its range, using floating and fixed gillnets, longlines, bottom nets, fish traps, trawls, and hook-and-line. The meat is eaten or used as bait for other fishes, the fins are valued for shark fin soup, and the carcasses are processed into fishmeal. The meat can also be processed with glacial acetic acid to obtain a gel powder that can be used as a protein supplement in cereal foods, a biodegradable film for wrapping seafood, or a binder in sausages and other foods.
Spadenose Shark Recorded Attacks on Humans: Not a threat to humans.