Salmon Catfish (Neoarius graeffei)

Choose a Salmon Catfish only if you can house a big, venomous predator

The Salmon Catfish is Neoarius graeffei, a sea catfish of the family Ariidae from northern Australia and southern New Guinea. Its tall, pointed dorsal fin and deeply forked tail give it the look of a small shark, which is why it is also sold as the Australian Shark Catfish. Fishes of Australia lists Blue Catfish, Blue Salmon Catfish, Forktail Catfish, Lesser Salmon Catfish and Smaller Salmon Catfish among its names, and older books call it Arius graeffei or Arius australis. Planet Catfish describes it as dusky grey overall, often with a bluish tinge, and white underneath; Fishes of Australia says creamy to pinkish below.

We want every buyer to know the facts first. This fish grows to 35–60 cm, it carries venomous fin spines, it swims actively in groups in the wild, and it eats fish. It is a specialist animal for an experienced keeper with an exceptionally large aquarium or indoor pond, not for a community tank. If that is you, it is a striking, characterful fish; if not, please choose something smaller.

Check the facts before you buy

The name comes from the Greek arios, warlike, a reference to the well-developed fin spines, and the species honours the naturalist E. Gräffe. FishBase lists it as Least Concern on the IUCN Red List (assessed in 2019).

Select one fish and plan for its full size

One purchase supplies one live Salmon Catfish in the standard size we receive, which is a young fish far smaller than the adult. Sex is not specified. Planet Catfish notes that females have longer, more rounded pelvic fins than males, but young fish are hard to sex. The gallery images are representative, prepared from a reference photograph, and do not show the individual you will receive.

Decide between one fish and a group

FishBase notes that large groups of juveniles are often found in the wild, and Planet Catfish calls it an active, shoaling species. A group of adults, however, needs space on the scale of a public aquarium. Be realistic: size the system for the number of adult fish you will keep, not the number of juveniles that fit today, and buy only what the finished system can hold. Read our delivery and Live Arrival Guarantee policy before ordering a large fish.

Plan an exceptionally large aquarium or indoor pond

None of the species sources we checked publishes a minimum aquarium size for this fish. OATA's care sheet for very large fish says such species usually need an exceptionally large aquarium, often in excess of 500 litres, that an off-the-shelf aquarium is unlikely to be big enough in the long term, and that indoor heated ponds are an alternative. It adds that active swimmers need more space than sedentary fish of the same size, and the Salmon Catfish is an active swimmer.

As a yardstick, Seriously Fish asks for a base of at least 240 × 90 cm for another catfish of the same 60 cm standard length, the sailfin pim, which spends its days resting in cover and cruises mainly at night. Treat that as a starting point for one adult Salmon Catfish, not a target. Our tank volume calculator converts any set of measurements into litres.

Run a four-step space check

1. Measure the swimming length: an active, shark-shaped fish needs long, unobstructed runs, so length matters more than height.
2. Count adult bodies: plan for every fish at 35–60 cm, plus every tank mate at its adult size.
3. Size the filtration: OATA notes that several large filters, or even a pond filter, may be needed.
4. Fit a strong lid: OATA warns that large fish can be jumpy, especially when newly introduced.

Build an open, sturdy layout

Planet Catfish recommends driftwood and rocks as hiding places, and its feature on the species adds soft sand or fine gravel, several hiding places among bogwood roots and rocks, and subdued lighting so that new fish settle quickly. OATA's guidance for large fish is to fix rocks and ornaments securely so they cannot be dislodged, to protect heaters from damage, and to choose a substrate without sharp edges that can be kept clean.

Divide the footprint by function

Set hard, alkaline water values and hold them steady

The published ranges differ, so the target column uses the band where all three overlap. FishBase also notes that adults tolerate a much wider spread, from 11°C to 38°C, but a stable aquarium should stay well inside the target.

ScotCat advises keeping the pH on the alkaline side and not letting it drop too low. Many UK areas have hard, alkaline tap water that already suits this fish, while soft-water areas will need buffering; your water company publishes figures for your postcode, and our water matcher compares them with the target. Our water chemistry guide explains how to raise and hold hardness and pH safely.

Decide on fresh or brackish water

FishBase records it in fresh, brackish and marine water, and notes that sea-going populations migrate upriver to breed while river populations studied did not. None of the aquarium care sources we checked requires salt or gives a salinity for aquarium keeping, so we do not quote one. Hard, alkaline fresh water is the simplest choice. If you run a brackish system, change the salinity in small steps and measure each step.

Separate habitat values from waste readings

OATA gives these limits for every very large fish and warns that such fish can be stressed by even small amounts of ammonia and nitrite.

Filter for a big, messy predator

Large meat-eating fish produce a great deal of solid waste. OATA advises that several large aquarium filters, or a pond filter, may be needed to control water quality and remove that waste, and that a heater is required year-round. Mature the filter fully before the fish arrives; our guide to the nitrogen cycle explains why, and our guide to aquarium filtration explains how to combine mechanical and biological stages.

Follow a weekly maintenance sequence

1. Test ammonia, nitrite, nitrate, pH and hardness, as OATA advises every week.
2. Change at least 25% of the water, OATA's weekly minimum, and more if nitrate climbs.
3. Treat new water with a conditioner that removes chlorine and chloramine, and match its temperature and hardness.
4. Siphon solid waste from the sand, working around the décor.
5. Rinse filter media only in removed tank water, never under the tap.

Feed meaty foods in measured portions

FishBase lists a wild diet of insects and other arthropods, molluscs, prawns, crayfish, fish, aquatic plants and bottom detritus, and Fishes of Australia adds worms and even small mammals. Planet Catfish says it accepts a wide variety of live and prepared foods. ScotCat's keepers fed earthworms, frozen brine shrimp, prawns, pellets, tablets and large flake. OATA recommends large pellets for very large fish, with larger frozen foods such as mussel, shrimp and lancefish for carnivores.

Build one measured meal

• Use a large sinking staple: a quality catfish pellet sized for the fish's mouth.
• Add meaty variety: prawn, mussel, lancefish and earthworm through the week.
• Measure the portion: OATA advises offering only what is eaten within a few minutes, once a day.
• Feed in the evening: Planet Catfish's feature suggests an evening feed after the main lights go off.
• Skip live feeder fish: they are not needed and can bring disease into the aquarium.

Handle it with care: the fin spines are venomous

Fishes of Australia warns that this catfish has venomous serrated fin spines that may inflict a very painful wound, and ScotCat describes the dorsal and pectoral spines as poisonous, with punctures taking a long time to heal. FishBase classes it as traumatogenic, able to wound people. OATA advises double-bagging catfish so that spines cannot puncture the bag.

Follow a safe-handling routine

1. Never lift the fish with bare hands.
2. Guide it into a large, rigid container under water rather than lifting it in a net, where the spines tangle.
3. Wear thick waterproof gloves for any work close to the fish.
4. If you are stung, clean the wound and seek medical advice.

Introduce it to a mature system

Large fish may travel in boxes or buckets as well as bags. Use OATA's floating method: lights off, float the sealed bag for about 10 minutes to equalise the temperature, add small amounts of aquarium water over up to 20 minutes, then guide the fish into the aquarium with as little transport water as possible. Our guide to acclimatising new fish covers each step.

Use a first-week checkpoint plan

Watch for warning signs

OATA lists the changes worth watching in any large fish. A healthy Salmon Catfish swims steadily, feeds eagerly and keeps its fins spread.

Screen tank mates by size

Planet Catfish advises keeping it only with fish of equivalent size or larger, and ScotCat suggests larger cichlids because it can be carnivorous. In the wild it eats small fish, so assume that anything that fits in its mouth will be eaten as it grows.

Decide from the suits and avoid list

Fish that can match it as adults include the Oscar Cichlid (see our Oscar care guide) and, for a brackish system, the Spotted Scat; the Tinfoil Barb is another large, fast fish for very big aquariums, but introduce it only once it is too large to swallow. For related large catfish, compare our Shark Catfish (Arius jordani) and Silver Catfish, or browse other catfish, brackish fish, centrepiece fish and all our catfish and plecos. Check every mix with our tank mates tool before buying.

Understand its breeding biology

The male is a mouthbrooder, and the sources differ on the details. Planet Catfish says it spawns in the wild in spring or early summer at about 26°C, with males carrying up to 120 eggs for six to eight weeks. Fishes of Australia says males brood the eggs and young fry for four to six weeks, that females lay large eggs up to 14 mm across, and that breeding is annual in late spring and early summer. ScotCat gives two to four weeks of brooding and reports young of about 6 cm at two months. FishBase gives a breeding season from September to February. OATA notes that it would be unusual for very large fish to breed in a home aquarium.

Answer Salmon Catfish buying questions

What is a Salmon Catfish?

It is Neoarius graeffei, a sea catfish of the family Ariidae from northern Australia and southern New Guinea. It is also sold as the Blue Salmon Catfish, Lesser Salmon Catfish, Blue Catfish, Forktail Catfish and Australian Shark Catfish.

How big does a Salmon Catfish get?

FishBase and Planet Catfish give 60 cm standard length, measured without the tail. Fishes of Australia says it commonly reaches 35 cm, and ScotCat suggests about 50 cm, somewhat smaller in aquariums. Plan for a fish of at least 35–50 cm.

What size aquarium does it need?

No species minimum is published by the sources we use. OATA says very large fish usually need an exceptionally large aquarium, often well over 500 litres, or an indoor heated pond. As a yardstick, Seriously Fish asks for a 240 × 90 cm base for another 60 cm catfish.

Does it need brackish water?

No. It lives in rivers and lagoons as well as estuaries and the sea. The aquarium care sources we checked do not require salt and favour hard, alkaline water. None gives an aquarium salinity, so we do not quote one; if you choose a brackish set-up, change it slowly and measure every step.

Is the Salmon Catfish venomous?

Yes. Fishes of Australia warns that its serrated fin spines are venomous and can give a very painful wound, and ScotCat notes that puncture wounds can take a long time to heal. Never handle it with bare hands.

What does it eat?

It is an opportunistic predator. Offer large sinking pellets and meaty frozen foods such as prawn, mussel and lancefish, plus earthworms. It will eat any fish small enough to swallow.

Which tank mates suit it?

Only robust fish of equal size or larger, as Planet Catfish advises, such as large cichlids or, in brackish water, scats. Avoid every fish that could fit in its mouth.

Can it be bred at home?

Very unlikely. Males brood the large eggs and young in their mouths for several weeks, and breeding is recorded in the wild rather than in home aquariums.

Consult the care references

• FishBase: Neoarius graeffei: classification, habitats, water range, temperature tolerance, maximum length, wild diet, breeding season and IUCN status.
• Planet Catfish: Neoarius graeffei: names, synonyms, etymology, identification, sexing, water values, décor, compatibility and mouthbrooding.
• Planet Catfish Catfish of the Month, July 2019: Neoarius graeffei: substrate, hiding places, lighting and evening feeding.
• Fishes of Australia: Blue Catfish, Neoarius graeffei: Australian common names, colour, size, distribution, habitats, wild diet, male mouthbrooding and venomous spines.
• ScotCat: Neoarius graeffei factsheet: adult size in aquariums, water values, foods, tank mates, spines and breeding notes.
• Seriously Fish: Leiarius pictus (aquarium base used only as a size comparison): names, distribution, habitat, size, aquarium base and volume, water values, feeding frequency, tank mates, sexing and lifespan.
• OATA: How to look after very large fish / tankbusters: UK guidance for very large fish on aquarium size, filtration, décor, cover and feeding.
• OATA: How to look after freshwater catfish: UK guidance for catfish on water quality, sand, introduction, handling, feeding and health signs.
• Tropical Fish Co delivery policy: current dispatch days and Live Arrival Guarantee terms.