Mulloway, Northern

(Protonibea diacanthus)

Commonly referred to as Kingies or croakers! (Most large fish species are called Kingies in the far N/W)

There are two species of Mulloway commonly encountered throughout Australia, the northern variety of this species can be encountered northwards from the Exmouth gulf region right up and into the magnificent Kimberley and around to Darwin. Juvenile mulloway thrive in healthy estuary and coastal inshore environments where they mainly feed upon crustaceans which make up for 50 – 80 percent of their diets. Larger adult mulloway prefer a diet of squid and fish and also inhabit the same areas as juveniles but are not as common around brackish waters. This northern species of mulloway is considered to be a much stronger species although both specimens grow at around the same rate to eventual size. These larger fish are a highly prized target for many anglers who put in countless hours of effort chasing them. Mulloway are also referred to as jewies, this nick name comes from the ivory like jewels which are actually ear bones located in the skull of the fish. All fish species possess these ear bones with the grunter or croaker family possessing much larger jewels than normal. It is said that if an angler fails to remove the jewels of their first large mulloway they will never be lucky enough to catch another! I can happily remember releasing my first over fifteen kilos and have caught many since. The satisfaction of releasing a big, old fish back into its environment soon outweighs the need to stare at jewels in a jar!


Northern mulloway can be located from as far south as Exmouth Gulf right up into the magnificent Kimberley region throughout Western Australia and also from northern QLD up into the Northern Territory.


Northern Mulloway grow to around 55kg in weight here in Australian waters although they are generally encountered in the 20 – 45kg region. Larger specimens are commonly found around the Kimberley region in W.A. and also throughout the Northern Territory and parts of northern QLD They are a slow growing species that has received a huge amount of fishing pressure over the years, I believe they should be treated with the upmost of respect at larger sizes and released immediately upon capture. Mulloway breed in shallow estuary systems before making their way back out to inshore coastal environments such as shallow reef systems, rock bars and under water wrecks.


Northern mulloway prefer deeper sections of shallow estuary systems and can be located up as far as brackish waters when juveniles. Larger mulloway can also be encountered in similar locations but will also travel out into offshore coastal environments such as surf beaches, rocky headlands and off shore reef systems and under water wrecks.


Northern mulloway are a heavily scaled fish with a bright silver colouration shading to darker browns and purples in fish landed in poor water quality. Northern mulloway fade to a darkish black colouration upon death and appear yellowish in colouration depending on water quality when alive. The tail can be bright yellow when fish are captured in clean ocean environments or darker brown in colour when encountered in estuary environments. Mulloway have a long torpedo shaped body with a large paddle tail that is concaved in shape. There is a series of gold coloured spots that run horizontally down the side of the fish with this becoming more apparent with size and age. The head is tapered to a large mouth full of sharp pincer like teeth designed for holding prey securely before crushing and swallowing. Mulloway posses a set of crushing plates designed to crush and de scale prey items before consumption. Mulloway have always been famous for their timid, shy approach to taking a bait, this is simply the fish trying to crush and scale the bait before consumption. Be patient and let them eat it properly before striking!

Taste rating

  • Fifty Taste Rating

Small mulloway to 60 – 70cm are referred to as soapies, this is due to the mushy textured, soapy flavoured flesh often encountered when eating mulloway at this small stage. Larger mulloway have a much firmer textured, pleasant flavoured flesh as long as they have come from a clean ocean environment. Larger specimens that have spent long periods of time in northern estuary systems are generally very poor eating and should be released upon capture to breed.

Sport rating

  • Eighty Sport Rating

Northern mulloway are a very respectable sport fish when encountered on any tackle and are practically unstoppable when hooked in troublesome environments such as bridge pylons and mooring buoys. They can be dirty fighters with infinite knowledge of their surroundings and how to use them to advantage!

Tackle requirements

Light spin and overhead outfits rated 3 – 6kg are ideally suited to targeting smaller mulloway to 6kg with most bream styled combos proving ideal as most juvenile mulloway captures generally occur whilst targeting other northern estuary species such as bream and mangrove jack etc. Nylon line is preferred for targeting smaller mulloway with baits and not only allows the fish to move off with a bait without feeling too much resistance but also helps shore based anglers fishing rough, abrasive structures such as bridge pylons and rocky reefs etc. Braided line is ideal for casting long distance, when extra feel is needed or when fishing with lures and finesse styled outfits.

Larger mulloway require much sturdier gear which can vary greatly depending on the size of fish and the environment you have chosen to target them in. For instance, when targeting school sized mulloway which average 4 – 6kg from an ocean surf break a 6000 – 8000 class spin reel loaded with 20lb nylon or braided line mounted on a 10 – 12’ graphite or fibreglass beach rod would be ideal. Yet if you were chasing 20kg plus fish from a rocky headland a much heavier outfit would be necessary. Large Alvey side casts, overheads and spin reels can all be used depending on the casting ability of the angler and the environment chosen. Line choice comes down to the simple question of, “ Do I need to cast far and feel a lot? “ or “ Do I need thick, strong line in case it is dragged around and wrapped through structure?” Two hundred pound hand lines are also a popular choice of outfit whilst targeting northern mulloway around heavy structure, and for good reason! Leader materials should be light enough so as to not spook fussy fish yet thick and strong enough to withstand sharp teeth and rugged structures, 10 – 20lb is ideal for juvenile specimens with 40 – 60 for larger fish to 15kg and heavier 80 – 100lb for big, bad mulla’s around heavy structures such as deep water wrecks and reef.

Recommended baits, lures and rigs

Small Mulloway prefer to eat crustaceans such as crabs and prawns, they are generally encountered as a by catch when targeting other popular estuary species such as black bream. Larger mulloway prefer a diet of squid and fish although will happily slurp down a small river prawn intended for smaller game. This is what makes the mulloway the truly magnificent species it is, big hooks, big baits and heavy lines will not always prove best as mulloway are very fussy feeders that are perfectly in tune with their environment. Targeting large mulloway in quiet estuary environments is a real art and a skill that requires a lot of time and patience to master. Both small and large mulloway will take a variety of lures from soft plastics to hard bodied minnows and red/white feather jigs at times with this active style of fishing being generally conducted around bridge pylons, ocean rock walls and rocky head lands. Fresh and live baits such as Prawns, squid and small bait fish such as mullet or whiting are all ideal baits for targeting northern mulloway from most Western Australian locations and should always be presented as fresh and natural as possible. Rigs need to allow the mulloway to take the bait as freely as possible if any weight or unnatural feelings are sensed the mulloway will drop the bait and not return. Running sinker rigs are generally used when targeting mulloway of all sizes unless casting very long distance.

Handy hints and tips

The average serious mulloway angler lands one mulloway for every 50 hours of effort put in! Always use the freshest bait available and present it as naturally as possible,  fish lighter and try some aniseed oil on your hands if you are a smoker! (It helps to mask the scent of smoke which mulloway hate on bait!)

Preferred fishing times and tides

Low light periods such as sunrise and sunset are ideal times to target mulloway as is night around full and new moon phases. Rising tides are also favourable for mulloway fishing. Best of luck!


[What The Fish]