Hardnose shark

Lore & Background

The hardnose shark was described by German biologists Johannes Müller and Jakob Henle in their 1839 Systematische Beschreibung der Plagiostomen, who named it Carcharias (Hypoprion) macloti in honor of Heinrich Christian Macklot, who collected the type specimen from New Guinea. In 1862, American ichthyologist Theodore Gill elevated Hypoprion to full genus, with C. macloti as the type species, but in 1985 Jack Garrick synonymised Hypoprion with Carcharhinus. This species may also be called Maclot's shark. Its evolutionary relationships remain unresolved: a 1988 morphological study tentatively grouped it with several other Carcharhinus species, while molecular analyses have been inconsistent, with a 2012 study concluding it is the sister species of the Borneo shark. Teeth apparently belonging to the hardnose shark have been recovered from the Pungo River and Yorktown Formations in the United States and from the Pirabas Formation in Brazil, with the earliest fossils dating to the Lower Miocene (23–16 Ma).

Reader's Guide

The hardnose shark is common and gregarious, often forming large groups and associating with spottail sharks and Australian blacktip sharks. It is a predator of bony fishes, cephalopods, and crustaceans. Females have a biennial reproductive cycle, bearing litters of one or two pups after a twelve-month gestation period, with newborns measuring 45–55 cm (18–22 in) and sexual maturity attained at 70–75 cm (28–30 in). The maximum lifespan is at least 15–20 years. Harmless to humans, it is caught with gillnets and line gear by artisanal and commercial fisheries across much of its range, used for meat sold fresh or dried and salted, though its small size limits its economic importance. Its low reproductive rate may render it susceptible to overfishing, and given existing levels of exploitation, the IUCN has assessed it as Near Threatened. Off northern Australia, it makes up 13.6% of the gillnet catch and 4.0% of the longline catch, but since these losses do not appear to have diminished its population there, the IUCN has given it a regional assessment of Least Concern.

Did You Know?

• The hardnose shark is named for its heavily calcified snout cartilages, unlike other Carcharhinus species.
• It was originally described as Carcharias (Hypoprion) macloti in 1839 by Johannes Müller and Jakob Henle.
• Females give birth to only one or two pups every other year after a twelve-month gestation.
• The longest known distance traveled by a tagged individual is 711 km (442 mi).