The black spotted pufferfish or blowfish, Arothron nigropunctatus is also known as the dogface puffer or blowfish. They are a common sight on the reefs in East Africa and are frequently seen swimming around the reef. As with many other puffers, they have a symbiotic relationship with types of bacteria such as Pseudoalteromonas tetraodonis. This bacteria produces tetradotoxin which is a powerful neurotoxin. Unless you are Japanese and a highly trained fugu chef you should not consider eating this fish.
Black spotted pufferfish are not the most attractive looking fishes but because of their resemblance to a dog, they have a slightly endearing look about them. They have no scales or lateral line and have a set of protruding nostrils on the snout.
The background color is commonly a light grey or bluish grey color with black spots or a light brown background color. There is also a yellow coloration which is not commonly seen. This was once thought to be a separate species. All colorations have dark spots on them. The fins are usually tinged a yellow color and they have no pelvic fins. They have four strong teeth fused into a beak which are not unlike rat teeth, in that they continue to grow and need to be continually worn down. Full grown they can be up to 30 cm in length although usually they are slightly smaller.
As with all pufferfish or blow fish as they are sometimes known, they have the ability to take water into their stomach to swell themselves up, making it harder for a predator to fit them in its mouth.
IN THE WILD
Black spotted pufferfish are regularly seen swimming just above the reef and are very rarely seen swimming in open water, although this does happen occasionally. Despite their poisonous defense they take no chances and are usually near cover. If a diver nears them they will usually duck into a hole and are hard to approach closely.
They are territorial and are usually solitary. With their beak they can give a powerful bite and great care should be taken handing these fish. During the day they can often be seen on the reef top curled up with their tail wrapped against the body.
Black spotted pufferfish are found across the Indo Pacific area, excluding the Red Sea and live close to the reef and in lagoons to a depth of 25 meters. They can be seen in greater numbers around areas containing rubble.
They use their impressive looking teeth to feed on benthic invertebrates, sponges, algae’s and some corals and often chew the ends off branched corals. They are primarily nocturnal eaters.
Pufferfish are considered a delicacy in Japan and are bred commercially, so we know something of their behavior. The male constructs a flattened circle in the sand and when a female nears, will swim around throwing up sand. If the female enters the circle eggs are released by the female and fertilized by the male, these then drop into the sand and later hatch.
They are eaten as a delicacy in Japan and are captive bred for this purpose. It takes three years to train as a “‘Fugu” Chef and the whole process is controlled by law in Japan. If the chef makes a mistake it could easily be your last meal which appears to be the attraction for some.
They are kept by some aquarists but because of their constantly growing teeth, they require regular feeds on hard stony corals to prevent the teeth from growing too far and becoming unusable. They are not aggressive fish, but may attempt to eat smaller sickly fishes and may nip long finned fishes. Because of their potential size they require a large tank. They will also eat most invertebrates ranging from coral to crustaceans and are not suitable for reef tanks.
BLACK SPOTTED PUFFERFISH CLASSIFICATION
Species: A. nigropunctatus
Allen, G.R. 1997. Marine Fishes of Tropical Australia and South-east Asia. Western Australian Museum. Pp. 292. –
The Reef Guide
East and South Coasts of Southern Africa
Dennis King and Valda Fraser