Stellate puffer (Arothron stellatus)

The stellate puffer is a demersal marine fish belonging to the family Tetraodontidae. It is found in shallow water in the Indo-Pacific region. It is a medium-sized fish which grows up to 120 cm in length. Arothron stellatus feeds on benthic invertebrates, sponges, algae, the polyps of corals such as Acropora, crustaceans and mollusks.This pufferfish is diurnal. It is mainly solitary and defends a territory. Arothron stellatus contains a highly toxic poison, tetrodotoxin, in its ovaries and to a lesser extent its skin and liver, which protects it from voracious predators. It becomes toxic as it eats bacteria that contain the toxin. To ward off potential enemies, they can inflate their bodies by swallowing air or water.

photo credits: MiPe, Richard Ling, Alexander Vasenin

Mutualisms between organisms are extremely common and many examples have been studied. Bumble bees obtain nectar from flowering plants and in return, help pollinate the plants. Cleaner wrasse eat parasites off larger fish and at the same time, get food and protection. Recently, it has been discovered that a species of wild bird in Mozambique, the “honeyguide”, has developed a mutualistic relationship with humans, where hunter-gatherers using a distinctive call will signal the birds to lead them to the honey. Humans receive honey and the birds get the beeswax they are after. Cooperation in nature is a beautiful reciprocal exchange, but what prevents one or both parties in these mutualisms from “cheating” and taking advantage of the relationship?

Image: White-spotted puffer (Arothron hispidus) is being cleaned by Hawaiian cleaner wrasse, Labroides phthirophagus. CC BY-SA 3.0 via Wikimedia Commons.

Stellate puffer juvenile  (Starry Pufferfish)

Arothron stellatus (Tetraodontiformes - Tetraodontidae), better known as Stellate puffer, is a relatively uncommon fish which occurs in patch reefs and coral slopes near sandy areas of clear lagoon and seaward reefs, in the Indo-Pacific and the Southeast Atlantic.

This puffer can be recognized by its coloration. Adults are white with numerous small black spots that become relatively smaller and more numerous as the fish grows. Juveniles are orange with small black spots. They have diagonal black bands crossing the abdomen.

The species grows to 1.2 m in length.

References: [1] - [2]

Photo credit: ©Benjamin Naden | Locality: Bali, Indonesia

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