The slender-spined porcupine fish or globefish, Diodon nichthemerus, is a porcupinefish

Porcupinefish

Porcupinefish are fish of the family Diodontidae, , also commonly called blowfish ....

 of the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Diodontidae, found in the waters of southern Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, as far north as Port Jackson

Port Jackson

Port Jackson, containing Sydney Harbour, is the natural harbour of Sydney, Australia. It is known for its beauty, and in particular, as the location of the Sydney Opera House and Sydney Harbour Bridge...

 to Geraldton, Western Australia

Geraldton, Western Australia

Geraldton is a city and port in Western Australia located north of Perth in the Mid West region. Geraldton has an estimated population at June 2010 of 36,958...

. It is most common in Port Phillip Bay and the coastal waters of Tasmania

Tasmania

Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...

 in shallow coastal waters and under manmade jetty

Jetty

A jetty is any of a variety of structures used in river, dock, and maritime works that are generally carried out in pairs from river banks, or in continuation of river channels at their outlets into deep water; or out into docks, and outside their entrances; or for forming basins along the...

s.

It is one of the smallest members of the porcupinefish family. It is similar in appearance to the Three Bar Porcupinefish (Dicotylichthys punctulatus) only smaller (growing to a maximum length of 28cm) and with slight differences in its markings. It feeds on Benthic zone

Benthic zone

The benthic zone is the ecological region at the lowest level of a body of water such as an ocean or a lake, including the sediment surface and some sub-surface layers. Organisms living in this zone are called benthos. They generally live in close relationship with the substrate bottom; many such...

 invertebrates. It has slender yellow spines used in predator defence and has the ability to blow its body so that the sharp spines protrude when alarmed.