A. piauiensis has the easternmost range of the species in the genus. The R. Parnaíba forms from main headwaters on the Chapada das Mangareiras, and may have received part of its fauna from eastern tributaries of the R. Tocantins, but the closest relative of A. piauiensis may be A. caetei from the R. Caeté and R. Apeu, south of the Ilha de Marajó. A discussion of the extralimital distribution of A. piauiensis must await more collecting in the R. Tocantins as well as in the rivers flowing into the Atlantic ocean south of the R. Amazonas. More material is also desirable for any serious comparison with A. caetei. A. piauiensis differs from the similar A. caetei, A. regani, and A. geisleii in morphometry, meristics and colouration."
Apistogramma piauiensis Kullander 1980
Holotype : MCZ 46831, 22.7 mm SL. : Brazil: Piauí, Lagoa Seca, about 1 km from camp on Rio Parnaíba at Barra do Longa (near Buriti dos Lopes). (3°08'S 41°54'W.) 1968.08.29. Leg. T. R. Roberts.
Paratypes :
MCZ 46830 - sex indet., 11.7 mm. Brasil (Piauí), Barra do Longa, R. Parnaíba (3°08'S 41°54'W). 1968.08.27 - 09.04. Leg. T. R. Roberts.
MCZ 52212 - sex indet., 13.3 mm. Same data as holotype.
Size) : The holotype (female) is 22.7/30.6 mm in length.
(Original description)
Apistogramma is a South American genus of diminutive often highly colorful members of the Cichlid family. Of all the "Dwarf Cichilds" kept by aquarists this genus alone stands out as the most prized. Other dwarf cichlids such as the Ram (Microgeophagus ramirezi) and the Checkerboard cichlid (Dicrossus filemantosa) are also absolute jewels among the dwarf cichlids - but in Apistogramma there is an entire genus full of brightly colored fish with elaborate fins and a captivating demeanor. Some people specialize in keeping only fish in this genus.
