The lizard tetras of the genus Iguanodectes are very rare aquarium fish. There are currently 8 recognized species. We are occasionally able to import the very colorful Iguanodectes geisleri from Venezuela and Colombia. This blackwater fish is particularly striking due to its three-colored longitudinal band in red, gold, and black.
The courting males can be easily recognized by their red ventral, anal, and caudal fins, which are always transparent in females. Additionally, the males have a red line running along their backs. Almost always, imports of I. geisleri include a second Iguanodectes species as bycatch, one that is virtually indistinguishable from I. geisleri in color: I. adujai. I. adujai has a significantly longer anal fin that begins just below the dorsal fin. The anal fin of I. geisleri begins well behind the dorsal fin. Another useful distinguishing feature is the usually very prominent caudal base spot of I. adujai. In I. geisleri, only the central caudal fin rays are black; a true caudal base spot is absent.
The unusual name “Iguanodectes” means “iguana biter,” which refers to the dentition; the German common name “Eidechsensalmler” (lizard tetra) was coined in a similar vein. The specific epithet “geisleri” is named in honor of Rolf Geisler (1925–2012).
Maximum size: approx. 8 cm; Temperature: 22–28°C; pH and hardness: not important for general care (tap water), but soft and acidic for breeding; coloration is most intense in blackwater. Diet: Omnivorous; Social behavior: Peaceful schooling fish; males tend to bite each other’s dorsal fins during rivalry fights; the resulting fin damage is harmless and heals on its own.
For our customers: Depending on their size, these fish are listed under codes 264612 through 264614 on our stock list. Please note that we supply exclusively to wholesale customers.
Text & Photos: Frank Schäfer
