Matt Clarke looks at the Orinoco eartheater, Biotodoma wavrini, and gets some tips on how to tell it apart from cupido.
Common name: Orinoco eartheater
Scientific name: Biotodoma wavrini
Origin: Found in the Rio Orinoco, which flows through Colombia and Venezuela, as well as in the middle and upper stretches of the Rio Negro in Brazil.
Size: Around 8-10cm/3-4".
Habitat: I caught B. wavrini in the middle Rio Negro over both wide expanses of white sand, and in shadier backwaters with a sand and leaf litter substrate. No plants, rocks or bogwood were found in either habitat - just loads of sand.
Aquarium: This species is a sand picker, so a sandy bottom is a prerequisite. It's moderately peaceful for a cichlid and should mix well with other fish from the region.
Water: Those I caught were in hot (30-37C/86-99F), extremely soft and acidic water - pH 3-5, GH virtually nothing. These fish had been acclimatised to hard water.
Diet: Bloodworms, brineshrimp, daphnia should be fine. May also take flakes and pellets when acclimatised to captive life.
Similar species: There are currently two species in the genus, B. wavrini and the better known B. cupido. Biotodoma cupido is found in Bolivia, Venezuela, Peru, Guyana and Brazil. Experts reckon that there are also several undescribed Biotodoma species in the trade which are still waiting to be formally named.
Identification: I've only just found this out myself, but I am reliably informed by Pete Liptrot of the Bolton Museum Aquarium that the position of the spot can be used to distinguish between wavrini and cupido! In wavrini the black lateral spot is below the upper lateral line roughly in the middle of the flank, but in cupido it's above the upper lateral line just under the dorsal fin. According to Dr Wayne Liebel, you can also use the position of the spot to place the other Biotodoma, allowing them to be split up into cf. wavrini or cf. cupido, depending on whether the lateral spot is below or above the upper lateral line respectively. Liebel says that one of these fish, B. sp. "Red Fin Santarem", may well prove a separate species.
Sexing: No idea... Some experts reckon male cupido have blue squiggles on the face, while females have blue spots. This isn't said to be reliable, but it's worth a shot for adult wavrini.
Breeding: B. cupido is rarely spawned. I'm not aware of wavrini being bred in aquaria. B. cupido is a substrate spawner. It excavates a pit and the sand and is thought to have bi-parental care.
Notes: Although these youngsters might look a bit bland, the adult fish (which is rarely seen for sale) is even more stunning than cupido. It develops blue facial squiggles, an irridescent colour and very long extensions to the fins.
Availability: Rare in the shops, but occasionally turns up as bycatch among geophagines exported from Manaus. These were imported from the Venezuela border by wholesaler Tom Halvorsen Ltd (07977 098127).
Price: Expect to pay around 15-20.