Boehlkea fredcochui

The Blue Tetra, also known as Cochu's Blue Tetra, is a lively and slender fish that brings a flash of iridescent blue to the upper and middle levels of the aquarium. Originating from South America, these fish are best known for their energetic swimming and shoaling behavior. For them to feel secure and display their best colors, they must be kept in a group of at least six. A smaller group can lead to stress and timidness.

They are generally peaceful but have a well-known tendency to nip at the fins of slow-moving or long-finned fish like Bettas, Angelfish, or fancy Guppies. Therefore, it's crucial to choose their tank mates carefully, opting for other fast-moving, short-finned species.

Caring for Blue Tetras is considered moderately difficult, mainly because they require stable water conditions. They thrive in a well-established tank with low water flow to mimic their natural habitat. Their omnivorous diet is easy to satisfy; a high-quality flake or micro-pellet food should be the staple, supplemented with occasional treats of frozen or live foods like daphnia or brine shrimp to promote optimal health and vitality. With proper care in a suitable environment, these dynamic little fish can be a rewarding addition to a community aquarium for up to five years.

The Blue Tetra (Boehlkea fredcochui) is a captivating characin admired for its subtle, electric-blue sheen that intensifies under proper lighting and against a dark substrate. Its 'medium' difficulty rating stems not from aggression, but from its need for pristine and stable water parameters and specific social housing. As an active species that relentlessly patrols the top and middle water columns, a tank with a generous footprint is essential to accommodate their behavior. A lid is also highly recommended, as their swift movements can sometimes lead to them jumping out of the water.

To create an ideal habitat that mirrors their South American origins, consider a blackwater biotope setup. The use of botanicals like catappa leaves or alder cones can help achieve the preferred soft, slightly acidic water conditions while releasing beneficial tannins that can enhance the fish's coloration and overall well-being. The low water flow requirement suggests they originate from slow-moving tributaries or floodplain lakes, so position filter outlets to diffuse the current, perhaps against the glass or through a spray bar.

Their social dynamics are complex. The minimum school size is a necessity, not a suggestion. In a sufficiently large group, their fin-nipping tendencies are often suppressed and redirected towards intra-species squabbles for hierarchy. However, in a small group or a cramped tank, this behavior is frequently redirected towards vulnerable tank mates. Ideal companions include other robust and fast characins (like Black Skirt or Serpae Tetras), Corydoras catfish for the bottom level, and Rasboras. Avoid any fish that is delicate, timid, or possesses long, flowing fins.

As omnivores, their diet should be varied to ensure they receive a complete nutritional profile. Rotating between high-quality flake food, micro-pellets, and frozen or live options like bloodworms, daphnia, and brine shrimp will not only keep them healthy but also encourage their most vibrant appearance. Feeding should occur daily in small amounts they can consume within a minute or two. Due to their low metabolism and waste production, they have a relatively small impact on the tank's bioload for their size, but regular water changes are still paramount for their long-term health.

Breeding in a home aquarium is notoriously difficult. They are egg-scattering spawners that show no parental care and will readily consume their own eggs. A dedicated breeding tank with very soft, acidic water, dim lighting, and fine-leaved plants like Java Moss is required to even attempt it. Conditioning the parent fish with abundant live and frozen foods is the first step, but successfully triggering a spawn and raising the minuscule fry is a challenge reserved for the most dedicated aquarists.

Boehlkea fredcochui is a small freshwater characin belonging to the expansive family Characidae. Its taxonomic placement within the genus Boehlkea makes it distinct from more common tetra genera like Hyphessobrycon or Paracheirodon. Native to South American river systems, its preference for soft, acidic water (pH 6.0-7.5) and low-flow conditions suggests an adaptation to blackwater tributaries or densely vegetated, slow-moving sections of larger rivers. Its wide tolerance for water hardness (36-215 ppm) indicates a degree of adaptability, though stability within this range is critical for its health.

Physiologically, B. fredcochui exhibits traits conducive to its ecological niche. A low metabolic rate, coupled with low oxygen consumption and waste production, suggests an efficient energy utilization strategy, beneficial in environments where food might be scarce or water has lower dissolved oxygen levels. The calculated bioload factor of 1.3 is a quantitative reflection of this efficiency, classifying it as a low-impact species relative to its size in aquaculture systems. Its primary diet is omnivorous, indicating a feeding strategy that likely includes small crustaceans, insects, algae, and detritus in its natural habitat.

Behaviorally, B. fredcochui is a rheotactic species that occupies the upper to middle strata of the water column. Its highly active, fast-swimming nature necessitates a significant horizontal swimming area in captivity, hence the minimum tank volume recommendation. The documented social characteristic of being 'triggered by long fins' is an important behavioral note, indicating a predatory or competitive response likely aimed at disrupting the locomotion of potential rivals or perceived threats. This fin-nipping is a classic characin behavior, often exacerbated by stress factors such as insufficient school size, lack of environmental complexity, or cramped conditions. Maintaining the species in shoals of at least six individuals is crucial for distributing aggression and promoting natural social interaction.

Reproduction in captivity is challenging, typical for many egg-scattering Characidae. Successful propagation requires simulating specific environmental triggers, such as changes in water chemistry (very low gH/kH), temperature fluctuations, and photoperiod manipulation, which are difficult to replicate consistently. The species exhibits no parental care and is oviparous, scattering adhesive or non-adhesive eggs among fine-leaved vegetation. The IUCN Red List status of 'Not Evaluated' (NE) signifies that its population dynamics and conservation threats in the wild have not been formally assessed, highlighting a gap in our ecological knowledge of this species.