A new species of dwarf cichlid from northern Peru has been named after famous cichlid biologist George Barlow.
The new species, Apistogramma barlowi, was described by German scientists Uwe Rmer and Ingo Hahn in the latest issue of the journal Vetebrate Zoology.
Apistogramma barlowi is easily distinguished from other members of the genus by the adult males having a disproportionately large head and enormously enlarged mouth with massive lips.
The new species is a member of the A. cacatuoides species complex and is further distinguished from congeners by the following characters: lyrate caudal fin in males that is divided horizontally into two colour zones (a yellow lower lobe and a bluish upper lob with spots, extended dorsal-fin membranes in males, a distinct breast band in basal part of the second vertical bar and posterior lateral in females, and caudal peduncle spot absent in both sexes.
Most importantly, Apistogramma barlowi exhibits facultative biparental mouthbrooding not seen in any other member of the genus.
According to the authors, Apistogramma barlowi sp. n. appears to be limited to forest streams (igaraps), with a preference for fast-flowing, cooler, and crystal-clear, acid to neutral water, with a typical habitat consisting of a small clearwater igarap, about one metre wide and approximately 30 cm deep, with fine white sand as bottom substrate, no submerged vegetation, rocks or pebbles, a pH of 4.8, electrical conductivity of 26 _S/cm at a temperature close to 29C.
The authors make the following observations about the reproductive biology of this species: n frontal threat behaviour, males are digging and building up little sand piles possibly demonstrating the size of their mouth to opponents as well as their capacity to carry larvae or fry to females selecting their partner for reproduction.
"Females take their larvae into the mouths and, unique within the genus, keep them inside almost constantly during their further development to the free-swimming stage.
"The larvae are usually put down only to permit feeding. In a significant number of cases facultative mouth-breeding by males has been registered too by different observersbut no published quantitative details are available on roles of the sexes in this specific brood care behaviour at the time being.
"According to our laboratory observation the degree of male participation, as well as the number of females carrying out mouth-breeding behaviour, may be dependent from maintenance conditions, especially the strength of current and the type of bottom substrate in the tank.
"We observed a significantly higher number of mouth-breeding females on fine sand and in strong current, mouth-breeding males exclusively under such conditions.
The fish has previously been sold in the trade under the name Apistogramma sp. "Maulbruter", which is German for mouthbrooder.
For more information, see the paper: Rmer, U and I Hahn (2008) Apistogramma barlowi sp. n.: description of a new facultative mouth-breeding cichlid species (Teleostei: Perciformes: Geophaginae) from northern Peru. Vertebrate Zoology 58, pp. 49"66.