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The spadenose shark ( Scoliodon laticaudus) is a species of requiem shark in the family Carcharhinidae. It is common in the tropical Indian Ocean and western , where it forms large schools in shallow water. A small shark reaching a length of , the spadenose shark is named for its distinctively flattened, triangular snout. It is a predator of small and . This species exhibits the most advanced mode of viviparity of any fish, in which the developed form a highly complex connection to the mother at a very small size. Females breed year-round, giving birth to six to 18 pups after a gestation period of 5–6 months. The spadenose shark is harmless to humans and is valued by artisan fishing and commercial fishers for its shark meat and fins. Its abundance ensures it forms a significant component of many fisheries in South Asia and Southeast Asia. The International Union for Conservation of Nature has assessed this species as Near threatened. This fish is also known as mori in Goa
Phylogenetics based on morphological and molecular data indicate the spadenose shark is one of the most basal members of its family, along with the related genus Rhizoprionodon and Galeocerdo, the tiger shark.Carrier, J.C. (2025). 084931514X, CRC Press. 084931514X In addition, anatomical similarities suggest this species to be the closest living relative of the , which diverged from the other carcharhinids some time before the Middle Eocene (48.6–37.2 million years ago).Martin, R.A. Hammerhead Taxonomy. ReefQuest Centre for Shark Research. Retrieved on August 30, 2009.
The spadenose shark has the most advanced form of 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. Newly Ovulation eggs measure only in diameter, while the developing become dependent on their mother for sustenance at a length of only . The placental stalk, formed from the yolk sac, has an unusual columnar structure and is covered by numerous long appendiculae that support a massive capillary network, providing a large surface area for gas exchange. The placental tissue contacts the uterus in a unique structure called the "trophonematal cup", where nutrients are transferred from the mother's bloodstream into the placenta.
Female spadenose sharks probably mate at least once per year, and breeding takes place year-round. The gestation period of the spadenose shark is 5–6 months long, and the young are born at a length of . The litter size is six to 18. Males mature sexually at a length of , and females at a length of . 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.Fowler, S.L. (2025). 9782831707006, International Union for Conservation of Nature and Natural Resources. ISBN 9782831707006
Despite its commercial importance, overall fishery statistics for the spadenose shark are lacking. A 1996 report found it to be the most common coastal shark on Chinese markets. Substantial numbers are caught by and fisheries; from 1979 to 1981, an average of 823 tons was caught annually off Verval, India. The spadenose shark is also caught as bycatch, particularly in gillnet fisheries off Kalimantan. The International Union for Conservation of Nature has assessed this species as near threatened; the spadenose shark's relatively short reproductive cycle may render it more resilient to fishing pressure than other sharks, though its low fecundity still merits caution. This shark may also be negatively affected by coastal development, due to its inshore habitat preferences.
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