top of page

77. Porcupinefish (Diodon hystrix)


The Porcupinefish (Diodon hystrix) gets its name thanks to its long spines, which are modified scales, and its ability to inflate itself, resembling a porcupine's defensive pose. When threatened, the Porcupinefish fills itself up to three times its original size by engulfing and swallowing a large amount of seawater and raises its sharp, pointed scales. This display of armature is very effective in deterring possible predators. When the threat vanishes, the engulfed seawater is expelled, the spiny scales lie flat again along their bodies, and the fish returns to its normal size.

In addition to this mechanical protection, the Porcupinefish also possesses a bio-chemical defence in the form of tetrodotoxin concentrates located in different body parts, such as its skin and liver. This toxin makes consumption of the fish very dangerous and potentially lethal. However, it is important to note that the spines themselves are not venomous and do not inject any form of toxin into possible predators.

The Porcupinefish is a durophagous carnivore, which means it consumes hard-shelled or exoskeleton-bearing organisms such as urchins, clams, crabs, and more. Its beaked mouth is ideal for hunting these invertebrates and crushing their hard exoskeletons. On the other hand, its large rubbery lips provide protection against spines and broken shells, preventing injury. Sometimes, the Porcupinefish also scavenges for food.

Hunting activities typically occur from dusk until dawn, with the Porcupinefish being most active at sunset and sunrise. During the daytime, this solitary nocturnal hunter primarily explores caves, crevices, and caverns.

The Porcupinefish can be found in all tropical waters across the entire planet. It prefers rocky reefs with overhangs and caverns, usually at depths of up to a maximum of 50m/165ft. While it can reach a total length of around 90cm/35 inches and a weight of 2.8kg/6.2lb, it is more commonly observed at smaller sizes. Any specimen longer than 50cm/40 inches is considered large.


When it comes to filming animals under water, obtaining a frontal shot can significantly enhance the quality of your footage. By positioning yourself in front of the animal, you allow the viewer to get a clear and captivating view of its face, expression, and features. This perspective can create a more engaging and immersive experience for your audience.

On the other hand, capturing fleeing fish or solely focusing on the back, rear, or tail of any creature might not yield the desired results. Such shots often lack the depth and detail that a frontal view can provide. Additionally, the movement away from the camera can make the underwater footage less engaging or dynamic.

To increase the chances of marine wildlife cooperating with your underwater filming efforts, it's important to maintain a calm demeanour. Animals are sensitive to human behaviour, and sudden movements can startle or scare them away. By staying calm and composed, you create an atmosphere of trust, allowing the animal to feel more comfortable and natural in front of the camera.

Remember, capturing an animal's best side requires patience and respect for its natural behaviour. Instead of chasing or scaring the animal, observe its movements and try to anticipate its actions. By doing so, you can position yourself strategically and capture those unique moments when the animal presents its most impressive features or behaviours.

Filming location:

This short underwater videoclip has been filmed in Mauritius 🇲🇺

Join us on a journey of discovery and entertainment as we explore fascinating marine wildlife topics and explore the many exciting underwater adventures on our YouTube channel and our Facebook page!

Discover the beauty beneath the surface with our online Marine Wildlife Videography course!


bottom of page