Atlantic Sharpnose Shark: Rhizoprionodon terraenovae

Family: Carcharhinidae
Common name(s)

Atlantic Sharpnose Shark.

Identification

Slender body. Snout long and pointed. Long upper labial furrows around mouth. Conspicuous row of hyomandibular pores extending backwards from the mouth. First dorsal fin origin posterior to pectoral fin free rear tip. Second dorsal fin origin over middle of anal fin base. Dorsal coloration olive-grey, grey-brown, or bronzy, with scattered white spots (in adults). Posterior margins of pectoral fins pale edged. Posterior margins of dorsal and caudal fin sometimes dusky or black; upper caudal lobe more-so.

Size

Maximum length approximately 110cm. Size at birth 29-37cm.

Habitat

Commonly found over soft mud and sand in shallow, protected bays and estuaries. Also on continental shelf from intertidal to 280m but usually 10m or less. Juveniles remain in brackish inshore water.

Distribution

Western North Atlantic. The Atlantic sharpnose shark is found from New Brunswick, Canada (in summer) to the Yucatan Peninsula, including the Gulf of Mexico.

Conservation Status

LEAST CONCERN

The Atlantic Sharpnose Shark (Rhizoprionodon terraenovae) is a very abundant, small coastal shark found in warm temperate and tropical waters of the western North Atlantic. It is caught in both commercial and recreational fisheries, and in incidental fisheries, mainly as bycatch in gillnets and shrimp trawl fisheries. A fast maturing, relatively fecund species with moderate population growth rates and short generation times. The juvenile and adult stages seem to affect population growth rates almost equally. The species is assessed as Least Concern because of its abundance and life history characteristics, which make it less susceptible to removals than many other species of sharks.

Citations and References
Cortés, E. 2009. Rhizoprionodon terraenovaeThe IUCN Red List of Threatened Species 2009: e.T39382A10225086. https://dx.doi.org/10.2305/IUCN.UK.2009-2.RLTS.T39382A10225086.en. Downloaded on 19 February 2021.

Reproduction

A viviparous species with yolk-sac placenta. 4-7 pups per litter. Gestation 10-11 months. Annual reproductive cycle. In North Carolina, mating takes place in shallow water from late May to the end of July.

Diet

Diet consists of small bony fishes and crustaceans.

Behavior

Atlantic sharpnose sharks migrate northward and into shallower water in the summer. In the Carolinas, the winter migration into deeper water begins in late October.

Reaction to divers

Unknown, but likely very shy due to its small size.

Diving logistics

Rarely if ever encountered by divers. The images on this page are of released animals, that I encountered while accompanying researchers from USM. Atlantic sharpnose sharks were the most common shark caught during tagging studies close to the mouth of the Mississippi River. However, visibility was heavily affected by run off from the river so this is not an ideal location to dive in.

Similar species

Caribbean Sharpnose Shark Indistinguishable in the field. These species can only be differentiated by spiral valve counts. However, the Caribbean species occurs further offshore in the Bahamas and Caribbean and along the Atlantic coast of South America.