Home › Sea Life › Marine › Vertebrates › Sharks › Daggernose Shark

Vital Facts about Daggernose Sharks

[Phylum: Chordata] [Class: Chondrichthyes] [Order: Carcharhiniformes] [Family: Carcharhinidae]

The severe downturn in population trend is one of the primary reasons why these unique requiem sharks need our attention and better protection.

This guide contains interesting facts and information about daggernose sharks (Isogomphodon oxyrhynchus), such as where they still exist, what they eat, and how they reproduce.

Daggernose Shark Habitat and Distribution

The daggernose shark is the only surviving member of the fish genus Isogomphodon.

In fact, in June 2019 the IUCN Red List listed them as being "Critically Endangered" (EN) and "Decreasing" in numbers.

The shallow marine neritic zones of tropical waters near northeastern coastlines of South America are the only places to find them, such as:

Isogomphodon oxyrhynchus tends to favour the muddy habitats found in river mouths, estuaries, and mangrove swamps.

Despite preferring water with high turbidity, they are able to survive in some brackish environments. Yet, unlike the bull shark, they have almost zero tolerance for life in fresh water.

Fun Fact: Our research team compiled a comprehensive list of funny scientific fish names which also explains how the daggernose shark got its "descriptive" common name, taxonomy, and classification.

Daggernose Shark Characteristics

Unlike many members in the shark phylum, the daggernose (I. oxyrhynchus) has an extended flattened snout. The acute triangular profile culminates in a sharp pointed tip.

It has small nostrils and tiny circular eyes that also have a translucent third eyelid (called nictitating membranes in fish species).

They have broad and flat upper teeth (up to 60) with smooth edges and there can be up to 56 serrated teeth set in the lower jaw.

Here's the thing:

Daggernose sharks have a robust body shape but they are quite small when compared with other requiem sharks, such as the blue shark and the blacktip reef shark.

The typical body colouring is a plain shade of gray on the top with a lighter colouration below, often light brown or yellow. Another feature used to identify them from other sharks is their large pectoral fins shaped like paddles.

Daggernose Shark Facts and Information with Pictures (Isogomphodon oxyrhynchus).Daggernose Shark Size

The average length of an adult male daggernose shark is around 1.4 metres (4.6 feet).

Whereas, the females tend to grow bigger and can be up to 1.6 metres (5.2 feet) long.

For the record, studies suggest the maximum weight of fully grown adults can be up to thirteen (13) kilograms (29 pounds).

Interesting Fact: Daggernose sharks can live for about nine (9) years. During this time they will spend most of their lifecycle swimming in depths between four (4) and forty (40) metres below the surface.

What Do Daggernose Sharks Eat?

The knife-like, dagger shaped nose is actually an adaptation to help them catch small, fast-moving prey (e.g. fish and squids).

Nonetheless, being typical carnivores, the daily diet of daggernose sharks can also include anchovies, catfish, and herring.

Daggernose Shark Reproduction

By and large, daggernose sharks will wait until the rainy season has finished before they start mating. Following that, gestation usually lasts for about twelve months.

Being viviparous fishes means the females will give birth to live young. In most cases, a litter will be limited to a maximum of two (2) pups per litter.

Threats and Predators

Despite having few "natural" predators in the wild, and an average lifespan around nine years, reports from the IUCN state that populations of daggernose sharks are decreasing at a rapid rate.

Ongoing threats to this critically endangered species, and why daggernose sharks are on the brink of extinction, include:

So, exactly how many daggernose sharks are left? As of 2013, the population was estimated to be less than 250 individuals.

However, there are other shark species close to extinction. Some of the most endangered are the African spotted catshark (Holohalaelurus punctatus), the Angel shark, the Ganges shark (Glyphis gangeticus), and the Irrawaddy river shark (Glyphis siamensis).

Fun Fact: Another section explains why humans are the deadliest animal and why sharks do not kill most humans - nowhere near!

Related Information and Help Guides

Note: Read about the day when our scuba team went swimming with sharks in Thailand as part of an organised shark release project.

Divers also enjoyed reading about...