Beautiful Red Spotted Sucker - Erromyzon kalotaenia

Red Tailed Black Shark (Erromyzon kalotaenia)

The Red Tailed Black Shark, Erromyzon kalotaenia, is a striking freshwater cyprinid with a deep velvet-black body and a vivid red to orange-red tail. Despite the name, it is not a true shark, but an active bottom-to-midwater river fish with a shark-like body shape and strong territorial behaviour as it matures. Best kept as a single specimen in a spacious, mature aquarium, this species suits confident community setups with robust tank mates and plenty of cover.

Common Name:
Red Tailed Black Shark, Red Tail Shark, Redtail Sharkminnow, Red-tailed Black Shark.

Scientific Name (Latin):
Epalzeorhynchos bicolor

Maximum Size:
Usually around 12–15 cm.

Water Type:
Freshwater

Origin / Natural Habitat:
Native to Thailand, historically associated with mainstream rivers, floodplains and connected river habitats. The species is now critically endangered in the wild, and aquarium trade specimens are captive-bred. Wild-type habitat would include riverine areas with submerged cover, open swimming space and bottom grazing opportunities.

Water Parameters:
Temperature: 22–27°C
pH Range: 6.0–7.5
Hardness or Salinity: Soft to moderately hard freshwater; adaptable when captive-bred, but stable, clean and well-oxygenated water is important.

Temperament:
Semi-aggressive and territorial. Young fish may appear peaceful, but adults often defend a chosen area and may chase similar-shaped fish, bottom dwellers or timid tank mates. Best kept singly unless housed in a very large aquarium with carefully planned territories.

Diet:
Omnivorous grazer and scavenger. Offer quality sinking pellets, algae wafers, spirulina flakes, vegetable-based foods, blanched courgette, cucumber or spinach, plus frozen daphnia, brineshrimp, bloodworm and mosquito larvae. It will graze biofilm and algae, but should not be relied upon as a tank cleaner.

Minimum Tank Size:
A minimum of 200 litres is recommended for a single adult, with a longer aquarium preferred. Larger tanks are strongly recommended for community setups, as this species needs swimming room and territory space.

Behaviour & Activity:
An active bottom-to-midwater fish that patrols the aquarium, grazes surfaces and spends time around caves, roots, rocks and plants. It may claim a favourite cave, piece of wood or shaded area and defend it from other fish. Adults are usually most successful when kept as the only shark-like cyprinid in the aquarium.

Aquarium Category:
Semi-Aggressive
Suitable with robust, active community fish such as medium barbs, larger danios, rainbowfish, sturdy rasboras, larger tetras, peaceful loaches with caution and medium catfish that are not easily bullied. Avoid very small fish, shy bottom dwellers, slow long-finned fish, other Red Tailed Black Sharks, Rainbow Sharks and similarly shaped territorial fish unless the aquarium is very large.

Special Requirements or Care Notes:
Provide a mature aquarium with strong filtration, regular water changes, open swimming space and plenty of hiding places such as wood, caves, smooth rocks and dense planting. Break up lines of sight to reduce territorial chasing. Do not keep in small community aquariums or with delicate tank mates. Captive-bred stock is the responsible choice, as this species remains highly threatened in its natural range.

Suitable for:
Intermediate fishkeepers

Availability:
Common in trade / Captive-bred

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Please note that Mother Nature is a wonderful thing, and variation in patterns and colours will occur — that is part of the unique beauty of these animals.