Aeoliscus strigatus, also known as the razorfish, is a member of the family Centriscidae

Centriscidae

Centriscidae is the family of snipefishes, shrimpfishes, and bellowfishes. A small family, consisting of only about a dozen marine species, they are of an unusual appearance, as reflected by the common names...

 of the order Gasterosteiformes

Gasterosteiformes

Gasterosteiformes is an order of ray-finned fishes that includes the sticklebacks and relatives.In the Gasterosteiformes, the pelvic girdle is never attached to the cleithra directly, and the supramaxillary, orbitosphenoid, and basisphenoid bones are absent. The body is often partly or completely...

. This unique fish adopts a head-down tail-up position as an adaptation

Adaptation

An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....

 for hiding among sea urchin

Sea urchin

Sea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. They inhabit all oceans. Their shell, or "test", is round and spiny, typically from across. Common colors include black and dull...

 spines.

Geographical distribution and Habitat

The razorfish is generally found in coastal waters from the central Indian Ocean

Indian Ocean

The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...

 to the Red Sea

Red Sea

The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...

 to Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

. Its natural habitat includes beds of sea grass and coral reefs, where sea urchins are found.

Physical description

The dorsal surface of the razorfish is covered by protective bony plates. They extend past the end of the golden yellow body and over the tail fin, which terminates in a sharp spine. A dark band runs the length of the fish. The razorfish can grow up to 6 in (15 cm) in the wild.

Diet, and feeding behaviour

The razorfish eats mainly small brine shrimp and other invertebrates. They have also been known to eat minute crustaceans in the zooplankton. In the wild they have been observed hiding in the spines of sea urchin

Sea urchin

Sea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. They inhabit all oceans. Their shell, or "test", is round and spiny, typically from across. Common colors include black and dull...

s, both as a defense mechanism and as a hunting mechanism. When threatened by larger fish, the razorfish darts away to a nearby sea urchin

Sea urchin

Sea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. They inhabit all oceans. Their shell, or "test", is round and spiny, typically from across. Common colors include black and dull...

. The larger fish, wary of being stung by the sea urchin

Sea urchin

Sea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. They inhabit all oceans. Their shell, or "test", is round and spiny, typically from across. Common colors include black and dull...

, which can sometimes be deadly, gives up the chase. They also hide in the spines for a completely different reason. When hunting, razorfish will hide among the sea urchin

Sea urchin

Sea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. They inhabit all oceans. Their shell, or "test", is round and spiny, typically from across. Common colors include black and dull...

 spines an wait for small invertebrates that feed on the urchins. When their prey gets close the razorfish will dart out and try to catch its dinner.

Aquarium care

As the full adult size of the razorfish is roughly 6 in (15 cm) it will need a fairly large aquarium, especially if it is not to be the only specimen in the tank. A minimum tank size of 20 gallons is adequate, however some aquarists have noted unusual growth if given a tank over 60 gallons. The razorfish needs a balanced ecosystem to survive, including algae, smaller fish, larger fish, coral, and if available a small sea urchin

Sea urchin

Sea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. They inhabit all oceans. Their shell, or "test", is round and spiny, typically from across. Common colors include black and dull...

. In the aquarium the razorfish will keep its head down position, but will not need to hunt the way it does in the wild. Care should be taken when handling sea urchins.

Temperature, pH, and salinity

The razorfish is considered a hardy fish in regards to temperature and pH. As long as the temperature is within the commonly accepted range of "tropical" and the pH is between 7.8–8.3, it will be fine. Salinity should be roughly 30 parts per thousand.