The giant bully, Gobiomorphus gobioides, is a sleeper of the genus Gobiomorphus, found in slow flowing streams within a few kilometres of the coast of the North

North Island

The North Island is one of the two main islands of New Zealand, separated from the much less populous South Island by Cook Strait. The island is in area, making it the world's 14th-largest island...

 and South Island

South Island

The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean...

s of New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

. Their length is up to 25 cm.

It is very similar to the common bully

Common bully

The common bully, Gobiomorphus cotidianus, is a sleeper of the genus Gobiomorphus, found in New Zealand. Their length is up to 15 cm.-References:*...

; they have seven spines in the first dorsal fin

Dorsal fin

A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...

 but giant bullies always have six.

The life cycle of giant bullies are thought to be amphidromous but it is not known for certain.