Valentinni’s Sharpnose Puffer (Canthigaster valentini)

Also known as the Saddled Puffer or Black Saddled Toby, Valentinni’s sharpnose puffer, is a species of puffer fish (Tetraodontidae) which is widely distributed throughout the tropical and subtropical waters of the Indian Ocean, the Red Sea and oceanic islands in the Pacific Ocean. C. valentini typically inhabits rocky and coral reefs, lagoons an external reefs at depths of at most 55 m. C. valentini is active during the day, feeding mainly on filamentous green and red algae, tunicates, and sometimes corals/bryozoans and other various other marine invertebrates. C. valentini is very poisonous and can cause harm if ingested. 


Animalia-Chordata-Actinopterygii-Tetradontiformes-Tentraodontidae-Canthigaster-C. valentini

Image: Jenny Huang



Tetrodotoxin, frequently abbreviated as TTX, is a potent neurotoxin. Its name derives from Tetraodontiformes, an order that includes pufferfish, porcupinefish, ocean sunfish, and triggerfish; several species that carry the toxin. Although tetrodotoxin was discovered in these fish and found in several other animals (e.g., blue-ringed octopus, rough-skinned newt, and Naticidae) it is actually produced by certain symbiotic bacteria, such as Pseudoalteromonas tetraodonis, certain species of Pseudomonas and Vibrio, as well as some others that reside within these animals.

Tetrodotoxin inhibits the firing of action potentials in nerves by binding to the voltage-gated sodium channels in nerve cell membranes and blocking the passage of sodium ions (responsible for the rising phase of an action potential) into the nerve cell.

TTX is extremely toxic. The Material Safety Data Sheet for TTX lists the oral median lethal dose (LD50) for mice as 334 μg per kg. For comparison, the oral LD50 of potassium cyanide for mice is 8.5 mg per kg, demonstrating that even orally, TTX is more poisonous than cyanide. TTX is even more dangerous if injected; the amount needed to reach a lethal dose by injection only 8 μg per kg in mice.

Blacksaddle Filefish (Paraluteres prionurus)

…a species of filefish (Monacanthidae) which is typically observed in pairs or small schools in reefs across the Indian and Pacific oceans.the blacksaddle filefish is known for mimicking the pufferfish Canthigaster valentini, C. valentini is highly poisonous, and P. prionurus is not an gains protection by looking like a poisonous species. The two species are often seen schooling together. 


Animalia-Chordata-Actinopterygii-Tetraodontiformes-Monacanthidae-Paraluteres-P. prionurus

Image: Jens Petersen

Ocean sunfish / マンボウ

External image

Mola mola

Ocean sunfishマンボウ(翻車魚)

Animalia Chordata Actinopterygii Tetraodontiformes Molidae
動物界 脊索動物門 条鰭綱 フグ目 マンボウ科

The photo taken at Yokohama Hakkeijima Seaparadise, Kanagawa, Japan.

American Whitespotted Filefish (Cantherhines macrocerus)

Also simply known as the “Whitespotted Filefish”, the American whitespotted filefish is a species of marine filefish (Monacanthidae) which occurs along the Atlantic coast of North America, ranging from Florida extending southward into the Caribbean. This species is distinct from C. dumerilii which also boasts the name “whitespotted filefish” but occurs in the Pacific/Indian oceans. American whitespotted filefish are omnivorous in nature, consuming an array of marine invertebrates like sponges, corals, and sea whips, along with plant matter like algae. 


Animalia-Chordata-Actinopterygii-Tetraodontiformes-Monacanthidae-Cantherhines-C. macrocerus

Image: Harold Hudson