Penguin tetras with shrimp

By the Shrimp Tank Hub editorsUpdated Oct 27, 2026Research-based

The penguin tetra (Thayeria boehlkei), also sold as the blackline penguin, false penguin or hockey stick tetra, has a thick black stripe that runs from the lower tail lobe along the body to the gill cover, and swims at a head-up angle (Seriously Fish, Maidenhead Aquatics). The name "penguin tetra" originally belonged to its rarer relative T. obliqua, whose stripe is limited to the tail area (Seriously Fish, Maidenhead Aquatics). T. boehlkei comes from parts of the upper Amazon in Peru and the rio Araguaia in Brazil (Seriously Fish), but almost all fish in the trade are mass-produced (Seriously Fish).

Penguin tetra at a glance

Will penguin tetras eat shrimp?

• Adult shrimp: possibly, depending on size. None of our sources tested penguins with shrimp. Aquarium Co-Op's tank-mate guide warns against medium-sized fish, and Practical Fishkeeping's Nathan Hill personally counts the larger tetras among fish that will eventually eat shrimp, though he notes some hobbyists keep them together. A greedy fish up to 2.4 inches long can fit a small male cherry shrimp or a freshly molted one in its mouth, in our reading.
• Shrimplets: yes. Seriously Fish describes the penguin as a micropredator of insects, worms, crustaceans and other small invertebrates, and Neale Monks at Practical Fishkeeping says pretty much any active fish, even a small tetra, sees hatchling shrimp as food.
• Eggs and berried females: safe while carried. Shrimp hold their eggs under the tail, but berried females are often the largest shrimp, so they have the best odds.

Penguins spend most of their time in the upper part of the tank (Maidenhead Aquatics), which gives bottom-dwelling shrimp in dense plants a little more breathing room. For smaller, gentler tetras, compare ember tetras with shrimp, neon tetras with shrimp and rummy-nose tetras with shrimp, or see the full cherry shrimp tank mates list.

Matching the water

Seriously Fish lists 72–82 °F, pH 5.5–8.0 and hardness up to 20 dGH, noting that farmed fish are very adaptable. Cherry-type shrimp tolerate 65–85 °F, pH 6.2–8.0 and GH 4–8 (The Shrimp Farm). By our comparison:

• With cherry shrimp: about 74–78 °F, pH 6.5–7.5 and GH 4–8 suits both. The water is easy; the predation risk is the hard part. See shrimp tank pH and GH and KH explained.
• With crystal and other Caridina: crystal reds do best at about 68–74 °F (see crystal red shrimp care), mostly below the penguin's 72 °F minimum, and the shrimplet risk is high. We wouldn't combine them (our reading).
• With Amano shrimp: Amanos grow larger than cherry shrimp and are the safer choice with mid-size fish (Practical Fishkeeping). See Amano shrimp care.

Keep conditions steady at water changes. See shrimp tank water changes and shrimp water parameters.

Tank size and setup

• Size: Seriously Fish suggests a base of at least 24 × 15 in. A school of 10 active fish uses the space, so bigger is better (our suggestion).
• Cycled tank: start with a mature tank, so the shrimp have a stable home before fish go in. See how to cycle a shrimp tank.
• Plants and cover: Seriously Fish suggests a heavily planted tank with a dark substrate, roots, branches and some floating plants for shade. Thick moss and foliage give shrimp hiding spots (Aquarium Co-Op). See java moss for shrimp and driftwood and botanicals for shrimp.
• Shrimp-safe intake: a sponge filter or pre-filter keeps shrimplets out of the filter (our suggestion). See shrimp-safe filters.

Keep a real school

Seriously Fish recommends at least 6 and preferably 10 or more. It says the fin-nipping sometimes blamed on penguins usually disappears in a proper group, since they squabble among themselves instead. Maidenhead Aquatics agrees that small groups can be slightly nippy and suggests avoiding long-finned tankmates. Females are rounder in the belly and a little less colorful (Seriously Fish).

Other good tankmates

Seriously Fish suggests other South American fish such as Hemigrammus and Hyphessobrycon tetras, pencilfish, Corydoras and Loricariid catfish, plus small cichlids. Maidenhead Aquatics says they make good dither fish for dwarf cichlids. Practical Fishkeeping and Aquarium Co-Op both say dwarf cichlids hunt shrimp, so skip them in a shrimp tank. See pygmy corydoras with shrimp, otocinclus with shrimp and dwarf pencilfish with shrimp.

Feeding both

Seriously Fish says penguins are unfussy and suggests regular small live and frozen foods such as bloodworm, Daphnia and Artemia alongside flakes and granules. Maidenhead Aquatics adds micropellets and mosquito larvae. Because they eat greedily, feed the fish first at the surface, then drop sinking shrimp food into a planted corner (our suggestion). See best shrimp food.

How to add penguin tetras to a shrimp tank

• Shrimp first. Practical Fishkeeping suggests letting the shrimp colony build up before adding fish, with plenty of plants and well-fed fish to reduce losses.
• Consider bigger shrimp. Neale Monks suggests larger shrimp such as Amanos when fish are likely to eat babies. See Amano shrimp care.
• Acclimate slowly to your water. See how to drip acclimate.
• Count your shrimp for the first few weeks; if adults go missing, move the fish.
• Quarantine the fish separately. Practical Fishkeeping says many fish medications are not safe for invertebrates. If fish get sick, ask a fish veterinarian or an experienced store about treatment that won't harm the shrimp. See how to quarantine and is copper toxic to shrimp.

Common mistakes

• Buying penguins for a breeding cherry colony.
• Keeping only 2 or 3, which makes nipping more likely.
• Adding dwarf cichlids, which hunt shrimp, alongside them.
• Too few plants and no moss for shrimp to hide in.

Track it

Log temperature, pH, GH and TDS on the free Water Parameter Log printable so you can keep the tank in the range both species share.

Frequently asked questions

Will penguin tetras eat cherry shrimp?

They will eat shrimplets (Practical Fishkeeping, Seriously Fish), and at up to 2.4 inches (Maidenhead Aquatics) they may take small adults too, in our reading. Amano shrimp are the safer match.

How big do penguin tetras get?

About 1.4 inches standard length per Seriously Fish, and up to 6 cm (2.4 inches) per Maidenhead Aquatics.

What water do penguin tetras need?

Seriously Fish lists 72 to 82 °F, pH 5.5 to 8.0 and up to 20 dGH. With cherry shrimp, about 74 to 78 °F and pH 6.5 to 7.5 suits both.

How many penguin tetras should I keep?

At least 6, preferably 10 or more (Seriously Fish). Small groups are more likely to nip (Maidenhead Aquatics).

Do penguin tetras nip fins?

They can in small groups, but Seriously Fish says it rarely shows when they are kept in proper numbers. Maidenhead Aquatics suggests avoiding long-finned tankmates.

Is a penguin tetra the same as a hockey stick tetra?

Usually, yes. Thayeria boehlkei is sold as the penguin, blackline penguin or hockey stick tetra; the original penguin tetra name belonged to T. obliqua (Seriously Fish, Maidenhead Aquatics).

Sources: Seriously Fish, Thayeria boehlkei (false penguin tetra) (false penguin tetra; upper Amazon in Peru and rio Araguaia; nearly all trade fish mass-produced; 36 mm SL; base 60 × 38 cm; heavy planting, dark substrate, floating plants; 22–28 °C, pH 5.5–8.0, up to 20 °H; micropredator, greedily accepts anything; bloodworm, Daphnia, Artemia, flakes, granules; peaceful; group of 6, preferably 10+; nipping rare in proper groups; Hemigrammus and Hyphessobrycon tetras, pencilfish, Apistogramma, Corydoras, Loricariids; females rounder; name originally given to T. obliqua; head-up swimming); Maidenhead Aquatics (fishkeeper.co.uk), Blackline penguin tetra (blackline penguin; up to 6 cm; 22–28 °C; pH 6–8, KH to 20; groups of 6+; upper-water shoaler and dither fish for dwarf cichlids; slightly nippy in small numbers, avoid long-finned tankmates; T. obliqua stripe restricted to the tail; flake, micropellets, mosquito larvae, brine shrimp, Daphnia); Aquarium Co-Op, Cherry shrimp tank mates (avoid medium to large fish; dwarf cichlids go after shrimp; dense foliage hides babies); Practical Fishkeeping, Can I safely add some shrimp? (any active fish, even a small tetra, sees hatchling shrimp as food; larger shrimp such as Amanos as an alternative); Practical Fishkeeping, What can I keep with shrimp? (larger tetras and barbs likely to eat shrimp in the author's view; dwarf cichlids hunt shrimp; build the colony first; hiding places and well-fed fish reduce losses; many fish medications unsafe for invertebrates); The Shrimp Farm, Red rili shrimp tank set-up and care (cherry-type Neocaridina: 65–85 °F, pH 6.2–8.0, GH 4–8). The shared water zones, shrimp-risk reading and stocking suggestions are our own.