Species description

Care, breeding and tankmates

Fish profile

Temperament

Semi-aggressive

They are very peaceful, slightly shy, and highly captivating when settled. They require plenty of hiding spaces among plants to feel confident. In the right environment, they are active and peacefully interactive with their own kind.

Diet

Carnivore

They are micro-predators requiring fine, high-quality foods that fit in their small mouths. Crushed flakes, micro-pellets, and live foods like microworms are readily accepted. Variety is crucial for keeping their immune systems strong and colors bright.

Sex ratio

School

A mixed-sex school of at least six to eight individuals is ideal. Males are slightly more colorful and will spar playfully for dominance. Keeping a larger group diffuses any potential stress and encourages natural behaviors.

Feeding frequency

Twice daily

Feed them small amounts two times a day to maintain their energy levels. Because they eat slowly and methodically, ensure the food remains suspended in the water column. Avoid large, infrequent feedings which can pollute the water before they finish.

Bioload

Marilyn's Pencilfish produces a very small bioload due to its diminutive size. They are excellent for heavily planted tanks where water parameters are highly stable. Their minimal waste makes tank maintenance straightforward and easy.

Flow

Stagnant

They originate from slow-moving streams and prefer a gentle, diffused water flow. High currents will severely stress them and prevent them from hovering naturally. A spray bar or sponge filter provides the perfect mild water movement.

Reproduction

Oviparous

Breeding is uncommon and requires a dedicated soft-water breeding tank. They scatter eggs among fine-leaved plants and offer absolutely no parental care. To successfully raise fry, the adults must be removed immediately after spawning.

Compatibility & tankmates

They are highly peaceful community fish best kept with other small, gentle species. Small rasboras, peaceful tetras, and dwarf corydoras make excellent companions. Do not house them with boisterous fish that could easily outcompete them for food.

Tank level

Top/Middle

They generally occupy the upper and middle sections of the water column. They enjoy hovering near plant leaves, constantly searching for microscopic organisms. They rarely venture to the extreme bottom of the tank.