Acestrorhynchus Isalineae

Datasheet

General Description

Acestrorhynchus Isalineae, a member of the Acestrorhynchidae family, belongs to the putative 'A. nasutus group' of closely-related species characterized by two dark, longitudinal stripes. Typically reaching a maximum size of 10.5 cm, the species displays unique patterning with stripes running from the snout to the caudal-fin base and from the lower maxilla to the caudal peduncle. Acestrorhynchids, notably cannibalistic, exhibit peaceful behavior towards tankmates too large to swallow but require caution when selecting community companions as they prefer to be in groups of four or more individuals.

Aquarium Setup

The aquarium for Acestrorhynchus Isalineae should replicate a flowing stream or river, featuring variably-sized rocks, sand, fine gravel, and water-worn boulders. Additional elements like driftwood, roots, and branches can be included to provide hiding spots. Plants suitable for sand or attached to solid surfaces can be added, with lighting tailored to the plant species. It is crucial to use a tightly-fitting cover due to their jumping ability and employ efficient filtration such as external canister filters or a sump system to manage waste. Regular water changes of 30-50% are essential to maintain water quality, as the species is sensitive to organic pollutants and water chemistry fluctuations.

Behaviour

Acestrorhynchus Isalineae displays a schooling instinct among juveniles, while older individuals tend to be more solitary but still group together periodically. They are not aggressive towards conspecifics, making them suitable for community tanks with peaceful species. It is essential to avoid introducing aggressively territorial or competitive tankmates to prevent conflicts. Moreover, acestrorhynchids are known to exhibit cannibalistic behavior, emphasizing the importance of maintaining all individuals at comparable sizes to prevent aggression within the group.

Feeding and Diet

As obligate piscivores, Acestrorhynchus Isalineae can consume relatively large prey compared to their size. While they may initially prefer live fish, most individuals can be transitioned to accept dead or dried food. It is crucial to avoid feeding mammalian or avian meat like beef heart, which can lead to health issues. Additionally, utilizing feeder fish is discouraged due to the risk of introducing parasites and diseases, with properly conditioned nutritional alternatives being more suitable for the species' diet.

Reproduction & Dimorphism

Observations of related species suggest that Acestrorhynchus Isalineae likely spawns in midwater, with the female stationary and the male displaying a 'figure-of-eight' swimming pattern. Parental care is absent, and sexually mature females are slightly larger and deeper-bodied compared to males. The species exhibits non-dimorphic sexual characteristics, with females developing size and body depth distinctions as they mature.

Habitat and Distribution

The species was initially collected from a tributary of Rio dos Marmelos in the Rio Madeira basin, Amazonas State, Brazil. Official records mainly refer to this location, but Acestrorhynchus Isalineae may have a broader distribution within the Madeira system. The natural habitat of the species consists of flowing waters with rocky substrates and ample hiding spots, resembling a typical river or stream environment conducive to their predatory behavior.