Giant Black Lined Pencil Fish – Ternetzi Headstander

The Ternetzi Headstander has a wide distribution throughout the Amazon, Araguaia, and Orinoco River basins, in addition to being found in the coastal rivers of the Guianas, and is known from rocky areas with rapidly flowing waters. Adults congregate in sizeable shoals and may be observed feeding on crustaceans, insects, plant matter, and worms. These fish attain a moderate size and require a spacious aquarium that measures at least 4ft x 18″ x 18″ (and preferably larger). Juveniles grow very quickly and should be given space from the outset in order to prevent stunting and associated health problems. The aquarium should be mature and aquascaped with a sand or small-grained, smooth gravel substrate, plenty of sturdy pieces of driftwood and an open swimming space along the front of the tank. Plants are not necessary, but will make the aquarium more aesthetically pleasing; however, as these fish will devour plants, it is essential to choose robust species such as Anubias spp. and Java Fern (Microsorum) that can be tied onto the decor. Of greater importance is the use of powerful filtration (ideally provided by external canisters) and a high level of oxygenation, perhaps provided by spray-bar returns situated above the water line and/or additional powerheads. High water quality is essential for this river-dwelling species, so partial water changes should be carried out on a very regular basis in order to keep nitrogenous waste to a minimum. Sturdy, tight fitting coverslides are requisite, as these fish are accomplished jumpers. Although gregarious in the wild, Ternetzi Headstanders can be rather quarrelsome when maintained in small groups in aquaria. For this reason, it is necessary to keep either a single specimen, or a group of at least 8 individuals together (introduced simultaneously), as then any belligerent behaviour will be spread throughout the shoal, and no one fish will bear the continual brunt of any aggression. Tankmates could include medium-large sized peaceful cichlids (particularly rheophilic species), medium-sized characins, talking catfish (doradids) and suckermouth catfish (loricariids). Tiny fish will be eaten, and long-finned species will be nipped at, so choose tankmates with care. Anostomus ternetzi is classified within the Family Anostomidae (headstanders), of which there are currently some 156 described species within 14 genera. Many species from this family swim at an oblique or head-down angle, hence the common family name of headstander. May also be seen on sale as Ternetz’s Anostomus or Ternetz’s Headstander.

• Species – Anostomus ternetzi
• Common Name – Giant Pencil fish, Ternetzi Headtander
• Origin – Brazil, Columbia, and Peru in South America
• Diet – Omnivore
• PH Range – Alkaline 6.5 – 7
• Temperature – Tropical 26-28°c
• Breed Type – egg scatterer
• Maximum Size – approximately 12cm
• Sex – Un-sexed