Of the five species currently assigned to the genus Trigonostigma (harlequin barbs) – the well-known common harlequin barb T. heteromorpha, the most recently described T. truncatus, the dwarf T. somphongsi, T. hengeli and T. espei – the last two are often confused; unfortunately, this also happens to us from time to time if we are not very careful.
The reason for this is that both species look pretty darn similar in the juvenile stage, i.e. at 1-2 cm in length. When fully grown up, they can hardly be confused; both species remain about one centimeter smaller than the common harlequin barb at a total length of 3 – 3.5 cm. Adult T. hengeli have a zone between the edge of the gill cover and the colored, orange-pink band that accompanies the wedge spot, which is colored light brown-grayish beige like the back, while in T. espei the entire body, including the front body, is colored bright orange (females) to purple (dominant males) without any gaps. Only the wedge spot is naturally black. You can find pictures of T. hengeli here: https://www.aquariumglaser.de/en/08-carp-like-fishes-2-barbs-minnows-carps-goldfish-etc/trigonostigma-hengeli-4/
If the origin is known, identification is also easy. T. hengeli is only found on the Greater Sunda Islands of Sumatra and Borneo, T. espei only in southern Thailand, Cambodia and Vietnam. But as I said, juveniles cannot be identified without knowing their origin. And at the beginning of the season (May/June) it is mainly juveniles that are on the market. T. hengeli are always sent from Indonesia as T. espei with a certain persistence. And so it is easy to explain how the misnomer sometimes reaches private aquarists and causes ongoing confusion.
All harlequin barbs are beautiful fish and highly recommended. T. espei require soft and acidic water for breeding. Like its well-known cousin, it usually spawns with its belly upwards on the underside of broad leaves of aquatic plants (e.g. Cryptocorynes), but is not quite as strict about this. Occasionally, spawn is also deposited on the upper side of the leaves in a normal posture. All ornamental fish food of a suitable size is eaten. The completely peaceful animals do not damage plants. The water temperature should be in the range of 24-28°C.
For our customers: T. espei has code 451951 (sm) to 451954 (lg-xlg) on our stocklist. Please note that we only supply the wholesale trade.
Text & photos: Frank Schäfer
