The bullrout (''Notesthes robusta''), also commonly called freshwater stonefish or kroki, is a pale yellowish to dark-brown coloured

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

that lives in tidal

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environmen ...

and slow-flowing streams in eastern Australia, from Southern

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

to northern

Queensland, Australia ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

.
It has on a very infrequent occurrence been caught at sea. Its spines are venomous. It is the only member of the genus ''Notesthes''.

Taxonomy and etymology

The bullrout was first formally described in 1860 as ''Centropogon robustus'' by the German-born British

herpetologist Herpetology (from Greek ἑρπετόν ''herpetón'', meaning "reptile" or "creeping animal") is the branch of zoology concerned with the study of amphibians (including frogs, toads, salamanders, newts, and caecilians ( gymnophiona)) and rep ...

and ichthyologist

Albert Günther Albert Karl Ludwig Gotthilf Günther FRS, also Albert Charles Lewis Gotthilf Günther (3 October 1830 – 1 February 1914), was a German-born British zoologist, ichthyologist, and herpetologist. Günther is ranked the second-most productive re ...

with its type locality given as

. The genus ''Notesthes'' was described in 1903 by the Australian ichthyologist James Douglas Ogilby as a monotypic genus for the bullrout. This taxon is included in the subfamily Tetraroginae within the Scorpaenidae in the 5th edition of '' Fishes of the World'' however other authorities place that subfamily within the stonefish family Synanceiidae, while other authorities classify this subfamily as a family in its own right. The genus name ''Netesthes'' combines ''notos'', which means

back The human back, also called the dorsum, is the large posterior area of the human body, rising from the top of the buttocks to the back of the neck. It is the surface of the body opposite from the chest and the abdomen. The vertebral column runs ...

, and ''esthes'', meaning "a garment", an allusion to the completely scaled back of this taxon. The specific name ''robusta'' means "stout" or "full-bodies" and allusion Günther did not explain but which maybe to its more robust body shape when compared to what was thought to be the closely related Eastern fortescue (''Centropogon australis'').

Description

The bullrout is big headed with bony ridges, a large mouth and a lower jaw which protrudes beyond the upper jaw. There are 7 spines on the operculum. There are 15 robust spines in the

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

and this part of dorsal fin is slightly concave towards the rear with the rearmost soft ray in the dorsal fin being attached to the caudal peduncle by a membrane. The head has no scales but the body is clothed in small scales. The overall colour is pale yellowish to dark brown broken by dark reddish-brown to greyish or black irregular mottling which can coalesce to create irregular bands. The maximum recorded standard length is , although a standard length of is mor typical.

Distribution and habitat

The bullrout is

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 else ...

to eastern Australia where it occurs from north of

Cooktown, Queensland Cooktown is a coastal town and locality in the Shire of Cook, Queensland, Australia. Cooktown is at the mouth of the Endeavour River, on Cape York Peninsula in Far North Queensland where James Cook beached his ship, the Endeavour, for repair ...

south to Pambula, southern New South Wales. This fish lives in the lower freshwater stretches of rivers and streams, as well as in bays and estuaries. It is typically encountered within aquatic vegetation or woody debris in still or slow flowing freshwaters where there are rocky, muddy or gravel substrates.

Biology

The bullrout is a rather sedentary species in which individuals spend most of the time lying in wait on the bottom or among weeds for prey to pass, it is an

ambush predator Ambush predators or sit-and-wait predators are carnivorous animals that capture or trap prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey ...

feeding on fishes and small crustaceans. They are known to migrate downstream in rivers during periods of heavy rainfall. They breed in freshwater and juveniles have been recorded from the upper reaches of rivers, upstream from barriers.

Danger to humans and first aid

The dorsal, anal, and pelvic spines on a bullrout have venom glands on them, and should be handled with extreme care.

References

External links

Fishes of Australia : ''Notesthes robusta''
{{Taxonbar, from=Q2479457 Tetraroginae Venomous fish Marine fish of Eastern Australia Fish described in 1903 Taxa named by Albert Günther