Sailfin Tetra Care Guide
Crenuchus spilurus · Freshwater Fish
What Sailfin Tetra look like
Crenuchus spilurus, commonly known as the Sailfin Tetra, exhibits a small, laterally compressed body that typically reaches a maximum adult size of approximately 2.5 inches (6.35 cm). The species is characterized by pronounced sexual dimorphism, with males displaying a dramatically enlarged, sail-like dorsal fin adorned with striking red, black, and white banding, which serves as a visual signal during mating rituals and territorial displays. The body coloration is generally brownish, featuring a prominent horizontal dark stripe along the lateral line and an identifiable eyespot at the base of the caudal fin. This tetra possesses a well-developed lateral line system, which aids in detecting vibrations in the water. Defensive adaptations include its ability to blend into the substrate due to its coloration and the presence of a relatively small, streamlined body that allows for quick evasive maneuvers in the presence of predators.
Behavior & temperament
The Sailfin Tetra is primarily a calm and social species, often found in small groups within its natural habitat in the Amazon basin. It exhibits a tendency to dwell in the mid to upper water column, where it engages in both foraging and social interactions. This species is not an obligate schooler but prefers to associate with conspecifics, displaying a loose social hierarchy where males may establish dominance through displays of their impressive dorsal fins. Breeding behavior involves egg scattering, with females releasing eggs in open water, which are then fertilized by males. The temperament of Crenuchus spilurus is generally peaceful, although males can exhibit territorial aggression during the breeding season.
Diet & feeding
In the wild, the Sailfin Tetra is an omnivore, feeding on a varied diet that includes small invertebrates, plant matter, and detritus. In captivity, it thrives on a balanced diet of high-quality flake food, supplemented with live or frozen foods such as brine shrimp and daphnia, as well as blanched vegetables to meet its nutritional needs.
Behind the name
Crenuchus (from Greek 'krenos', meaning 'spring' or 'source'); spilurus (from Greek 'spilos', meaning 'spot' or 'stain', referring to the eyespot on the tail).
Plan your tank
Check the numbers before you buy: tank volume, a stocking plan, cycle progress, water changes, and your ongoing care routine.
Keeping Sailfin Tetra?
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