Bully (Giant) Gobiomorphus gobioides
Scientific names: Gobiomorphus gobioides
Synonym: Eleotris gobioides
Common name: Giant bully
Gobiomorphus gobioides is a diadromous (live in fresh and seawater) species of sleeper goby endemic to New Zealand. It is found in coastal areas throughout the North and South Island. Its habits are tidal and estuarine areas and in non-tidal reaches, but not far from estuaries.
It can reach a length of 250 mm. It has a black dorsal surface, dark green sides and light green ventral area. Pectoral fins are broad and brown/green in colour. Dorsal, anal and caudal fins are dark green with a few yellow speckles. Eyes are black with a yellow ring around them. Head is dorsoventrally compressed and mouth is anterior. The operculum (a hard bony flap covering and protecting the gills) is light green in colour.
It is very similar to the common bully (Gobiomorphus cotidianus), but Gobiomorphus gobioides has seven dorsal spines, where the common bully has six.
It is an ambush predator and it has been observed using tidal flows during feeding, stationary waiting for prey to be swept passed it.
Not much is known of the ecology of this species. No larvae have been positively identified, so it is thought that they have a marine phase.