A new species of South American cichlid which has been in the aquarium trade for some time now has an official name.
The geophagine cichlid was described from the Rio Parnaiba in Brazil and has been named Geophagus parnaibae by Wolfgang Staeck and Ingo Schindler in a paper in the latest issue of the German journal Zoologische Abhandlungen Dresden.
The fish occurs in the Rio Parnaiba in Piaui and Maranhao states in the north east of Brazil and has previously been imported into the aquarium trade under the name Geophagus sp. "Parnaiba".
Geophagus parnaibae is one of the smallest in the genus with the largest type specimen measuring just 7.5cm/3" and the maximum size from aquarium specimens believed to be around 16cm/6". Adults are yellowish white with a grey head. There is a dark brown or black lateral spot on and below the upper lateral line and up to ten narrow horizontal lines on the flanks, as well as coloured longitudinal stripes on the tail.
During the rainy season the fish is found in fast-flowing small brooks and rivulets over open sand, but occurs in almost stagnant pools and ponds during the hottest parts of the dry season. Staeck and Schindler state that the water ranges in pH from 6.5-7.6 and has a conductivity of 20-350 microsiemens (about 1-11 GH) and temperatures from 24-31C.
Stomach analyses show that the new fish is an omnivore and feeds on plant material, such as seeds, as well as aquatic insect larvae and detritus.
The species has been bred in captivity already by Rainer Stawikowski and Uwe Werner who reported that it is a primitive larvophilous mouthbrooder which practises biparental care of the eggs and fry - the fish spawns on the substrate and picks up the larvae to mouthbrood them as soon as they hatch.
G. parnaibae is a member of the Geophagus surinamensis group and is one of more than a dozen fish in the Geophagus genus. Around 14 others have been described from the genus, with several others awaiting description, and many are sold in the aquarium trade. The members of the group are notoriously difficult to identify to species level, problems that are hampered by the number of undescribed species also present in the group.
Identifying the new species
Staeck and Schindler say that parnaibae can be told apart from Geophagus outside the surinamensis complex as it lacks an infraorbital stripe - a dark line running through the eye. Within the surinamensis complex it can be told apart from the similar-looking dicrozoster, proximus, brachybranchus, winemilleri and dicrozoster by its lack of a dark marking on the preoperculum.
G. camopoensis is similar in appearance and shares markings on the caudal fin. However, in camopiensis, brokopondo and surinamensis these are made up of pale blotches while in the new species they are distinct longitudinal bands. G. parnaibae also has a larger lateral spot than camopoensis, 17 spines rather than 16 and 10 rather than 11 dorsal fin rays.
Although the character of adult size is not useful with aquarium fish, the authors state that abalios, altifrons and megasema all get several centimetres larger than the new species at adulthood.
At a glance ID
G. parnaibae - dorsal: 17 spines, 10 rays; anal: 7 rays; 31 E1 scales
G. camopiensis - dorsal: 16 spines, 11 rays; anal: 7 rays; 31 E1 scales
G. abalios - dorsal: 18 spines, 11 rays; anal: 8 rays; 34 E1 scales
G. altifrons - dorsal: 18 spines, 11 rays; anal: 8 rays; 37 E1 scales
G. brachybranchus - dorsal: 17 spines, 12 rays; anal: 8 rays; 33 E1 scales
G. brokopondo - dorsal: 17 spines, 12 rays; anal: 8 rays; 33 E1 scales
G. dicrozoster - dorsal: 17 spines, 12 rays; anal: 8 rays; 36 E1 scales
G. megasema - dorsal: 17 spines, 12 rays; anal: 8 rays; 37 E1 scales
G. proximus - dorsal: 17 spines, 12 rays; anal: 8 rays; 33 E1 scales
G. surinamensis - dorsal: 17 spines, 12 rays; anal: 8 rays; 33 E1 scales
G. winemilleri - dorsal: 19 spines, 12 rays; anal: 8 rays; 35 E1 scales
For more details on the new species see the paper: Staeck W and I Schindler (2006) - Geophagus parnaibae sp. n. - a new species of cichlid fish (Teleostei: Perciformes: Cichlidae) from the rio Parnaiba basin, Brazil. Zoologische Abhandlungen (Dresden) 55: 69-75.