No established common name

Where they come from

Salvelinus maxillaris is a cold-water char from clear, rocky streams and lakes in the northern hemisphere. Think high-elevation or high-latitude water that stays cold year-round, with strong current and loads of dissolved oxygen. If you have kept brook trout or Arctic char, the vibe is similar.

Setting up their tank

Give them running river energy, not a placid pond. They want length, current, and cold, clean water. An 8-foot tank or indoor trough is a realistic starting point for a small group, and a proper chiller is non-negotiable. Lids need to be tight; they jump hard when spooked.

• Tank: 300-600+ liters for a single or pair; 800-1200+ liters for a small group. More length than height.
• Chiller: Size it for at least 2-3x the tank volume with headroom. Aim for 6-12 C most of the year.
• Flow: 10-15x turnover. Use river manifold pipes or directional pumps to make a strong, one-way current.
• Oxygen: Big surface agitation, venturis, or oxygen cone if you run dense stocking. Keep DO high.
• Substrate: Rounded cobble and pea gravel. Build some current seams and a few quiet eddies.
• Hardscape: Big stones for breaks in flow; no sharp edges. Minimal plants.
• Filtration: Oversized sump or canisters. Mechanical prefilter you can rinse every few days.
• Lighting: Dim to moderate. They relax with overhead shade or a dark back panel.

These fish are wastey and hate ammonia. I run heavy biofiltration and change 20-30% weekly, more if feeding hard. Trickling water over media boosts oxygen but can add heat, so insulate lines and place the chiller after the pumps.

• Temperature: 6-12 C typical, brief seasonal swing 3-15 C if you want natural cues.
• pH: 6.8-7.8. GH/KH low to moderate. Stability beats chasing a number.
• Dissolved oxygen: Keep it high; aim for 8 mg/L or more at your set temp.
• Flow layout: Strong laminar section for cruising, and eddies to rest.

What to feed them

They are carnivores that key on movement. A good salmonid pellet is the backbone; supplement with clean frozen or fresh foods. They learn to hand-feed but scatter pellets into the current so everyone eats without brawling.

• Staple: Quality cold-water salmonid pellets (sinking, small size to start).
• Extras: Earthworms, blackworms, chopped prawn, mussel, smelt, and the occasional insect larvae.
• Treats: Live river shrimp or crayfish pieces for enrichment, not daily.
• Schedule: 1-2 small feedings per day. Skip one day a week to keep water pristine.

How they behave and who they get along with

They are sight hunters and can be spooky. In current they hold stations behind rocks and bicker over the best lanes. In tight quarters they will bully the weakest fish, especially near food.

• Best kept: Solo or as a small, evenly sized group in a very large system with multiple current lanes.
• Tankmates: Other cold-water salmonids of similar size can work, but be ready to separate. Most smaller fish become food.
• Avoid: Warmwater species, invertebrates, and anything that cannot handle 6-12 C and heavy flow.

Breeding tips

Spawning at home is a project. You need seasons, cold water, a gravel bed, and very steady water quality. Males will color up and develop a little hook on the jaw as temperatures drop in fall.

• Cycle: Spring 8-10 C, summer 10-12 C, fall drop to 4-8 C with shortening day length.
• Site: 10-20 cm of clean gravel with strong downwelling flow. No silt.
• Adults: Well-fed but lean going into fall. Separate bullies so a pair can work the redd.
• Eggs: They settle in the gravel. Keep flow strong and clean; do not hover with a net.
• Raising young: Once hatched and yolk is absorbed, start very fine salmonid starter crumble in flow. Zero ammonia, zero nitrite.

Common problems to watch for

• Heat stress: Rapid gilling, hugging returns, going off food. Drop temp and blast aeration.
• Low oxygen: Surface gasping or hanging in the strongest jet. Increase agitation and cut feeding.
• Ammonia or nitrite spikes: Lethargy, red gills. Big water change, heavy aeration. For nitrite, a short-term 1-2 g/L plain salt blocks uptake.
• Saprolegnia fungus: Cottony patches on scrapes or eggs. Improve flow and cleanliness; treat promptly if it spreads.
• Gas bubble issues: From supersaturation via venturis or leaky pumps. Watch for bubbles under skin or in fins; fix the gas source.
• Jumping injuries: Tight lids and soft covers stop panic launches.