Iriatherina Werneri

Datasheet

General Description

The Threadfin Rainbowfish, scientifically known as Iriatherina Werneri, is a delicate species with specific care requirements. It possesses a unique morphology and color pattern within the Melanotaeniidae family. This fish is sometimes referred to as the "featherfin rainbowfish" due to its distinct appearance, distinguishing it from other members of its family. The genus is monotypic and exhibits characteristics such as soft dorsal fin spines, extended filaments in males' fins, and reduced premaxillary teeth.

Aquarium Setup

For optimal care, Threadfin Rainbowfish flourishes in a densely-planted tank with floating plants and driftwood to mimic its natural habitat. The tank should be well-aquascaped, and the addition of fine-leaved aquatic moss is recommended, especially for raising fry alongside adult fish. Moderate filtration is advisable as this species prefers sluggish waters and is sensitive to abrupt water parameter changes. It's crucial to avoid introducing them to biologically immature aquariums.

Behaviour

Threadfin Rainbowfish are notably peaceful but are not suitable for general community tanks as they may struggle to compete for food and can have their long fins nipped by certain species. They are best kept in groups of at least six individuals, ideally more, to reduce stress and exhibit natural shoaling behavior. Males showcase vibrant colors and interesting behaviors when vying for female attention within a group.

Feeding and Diet

In their natural habitat, Threadfin Rainbowfish feed on floating or suspended phytoplankton, diatoms, and zooplankton. In aquariums, they should be offered appropriately-sized live foods like Daphnia, Moina, and Artemia nauplii. They also accept small crushed dried foods. Regular feeding with live foods ensures their optimal health and vitality.

Reproduction & Dimorphism

Threadfin Rainbowfish are egg-scatterers without parental care. Spawning occurs more frequently in warmer temperatures where females lay eggs daily for several days. Males display to females during spawning, and successful mating leads to egg fertilization. Adult males feature extended unpaired and pelvic fins, are larger, and display more vibrant colors than females.

Habitat and Distribution

Threadfin Rainbowfish prefer slow-moving streams, freshwater swamps, lagoons, and billabongs with clear water and abundant macrophytes. They are commonly found in shallow, heavily-vegetated habitats less than 1.5 meters deep. Distributed along the southern coast of New Guinea and in various river basins in Australia, wild examples are rare in the aquarium trade, with most specimens commercially bred.