The upland bully (''Gobiomorphus breviceps'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of fish in the family

Eleotridae Eleotridae is a family of fish commonly known as sleeper gobies, with about 34 genera and 180 species. Most species are found in the tropical Indo-Pacific region, but there are also species in subtropical and temperate regions, warmer parts of th ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to freshwater habitats in

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. Both sexes have distinctive orange-brown dots all over the head. Adults generally reach a length of .

Description

Male upland bullies are larger and more stocky than females, with bolder markings. The face is profusely marked with orange spots, and there is a cream vertical band at the base of the

pectoral fins Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

. Like other ''

Gobiomorphus ''Gobiomorphus'' is a genus of fishes in the family Eleotridae native to New Zealand and Australia. They are typically small, benthic fishes with large, rounded fins and two dorsal fins. Many have an amphidromous lifecycle: the eggs are laid in ...

'' species, the first dorsal fin of males features a coloured stripe. The colour of the stripe in upland bullies appears to be locally variable. Many populations have bright orange dorsal stripes, however some have bright green, pink, yellow, cream or uncoloured stripes.

Life cycle

Upland bullies are neither

diadromous Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousan ...

nor migratory – they remain in freshwater for their whole lives. Over spring and summer, the male establishes and defends a ‘nest’ – usually a hollow beneath a rock. Males prefer larger nests, however when in the presence of a predator, more enclosed nest sites are favoured. While defending the nest, the male turns very dark, from brown to completely black. When a female is ready to lay eggs, she enters the nest and turns upside-down to lay several hundred to a thousand oval eggs in a close-packed, single layer attached to the nest's ‘ceiling’. The male then fertilises the eggs. The female leaves the eggs in the care of the male, which guards them until they hatch two to four weeks later. Females may lay eggs up to eight times over the spawning season, and one male may defend the eggs of more than one female. Fry rear in still waters on the edge of streams. They reach sexual maturity in their first year and have an average lifespan around 3–4 years.

Distribution

Upland bullies are widespread across the

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

, with large gaps on the west coast around the Tasman Mountains and from around

Hokitika Hokitika is a town in the West Coast region of New Zealand's South Island, south of Greymouth, and close to the mouth of the Hokitika River. It is the seat and largest town in the Westland District. The town's estimated population is as of . ...

south. They are present in the lower half of the

North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-largest ...

, from the headwaters of the Mokau River in the west to southern

Hawke's Bay Hawke's Bay ( mi, Te Matau-a-Māui) is a local government region on the east coast of New Zealand's North Island. The region's name derives from Hawke Bay, which was named by Captain James Cook in honour of Admiral Edward Hawke. The region is ...

in the east. Also present on

Stewart Island Stewart Island ( mi, Rakiura, ' glowing skies', officially Stewart Island / Rakiura) is New Zealand's third-largest island, located south of the South Island, across the Foveaux Strait. It is a roughly triangular island with a total land ar ...

. There are five distinct genetic and geographical groupings. The largest and most distinctive covers most of the east coast of the South Island, while the remaining four are closely related and are found in the north of the South Island and in the North Island. The North and South islands are connected by land during the ice ages, which allowed upland bullies in the north of the South Island to spread further north. Upland bullies in the large southern group are often larger and more boldly patterned than their northern counterparts. They can be found far inland as well as close to the coast. They are tolerant of a wide range of conditions but prefer slowly flowing water.

References

External links

Photograph of male

Photograph of female
{{Taxonbar, from=Q6418031

upland bully The upland bully (''Gobiomorphus breviceps'') is a species of fish in the family Eleotridae endemic to freshwater habitats in New Zealand. Both sexes have distinctive orange-brown dots all over the head. Adults generally reach a length of . Des ...

Endemic freshwater fish of New Zealand Taxa named by Gerald Stokell