Gymnochanda verae TAN & LIM, 2011

Etymology

Gymnochanda: from the Greek γυμνός, meaning ‘naked’, in reference to its scale-less body, and the generic name Chanda.

verae: named for Vera Kasim, ‘wife of our good friend and fish exporter Gunawan Kasim, in appreciation of her generous assistance and logistic support’.

Classification

Order: Perciformes Family: Ambassidae

Distribution

The type series was collected from ‘Gantung area of Pulau Belitung, Indonesia’, i.e., Belitung Island,  Bangka-Belitung Islands province, and no additional populations appear to have been found to date.

Habitat

Unconfirmed, but congeners tend to occur in low altitude, swampy freshwater habitats containing still or slowly-moving, acidic water with substrates of silt and peat.

Maximum Standard Length

20 – 26 mm.

Aquarium SizeTop ↑

Does not require a large aquarium but given its delicate nature and rarity minimum base dimensions of 60 ∗ 30 cm are suggested since smaller tanks are more susceptible to swings in water chemistry.

Maintenance

A densely-planted tank with floating vegetation and roots, twigs or branches and natural leaf litter would seem appropriate.

There’s no need to use natural peat, the collection of which is both unsustainable and environmentally-destructive.

Filtration should not be strong with an air-powered sponge-type unit ideal, and given it naturally inhabits pristine environments it should never be introduced to a new aquarium.

Water Conditions

Temperature: 20 – 28 °C

pH: 4.0 – 6.0

Hardness: 18 – 90 ppm

Diet

Small live foods such as Artemia, Daphnia, etc., should be considered essential, especially during the acclimatisation period, although frozen and dried alternatives may be accepted over time.

Behaviour and CompatibilityTop ↑

Unlikely to make an ideal community fish and best kept in a species-specific set-up, or perhaps alongside comparably-sized, equally peaceful species such as Boraras, Sundadanio or Indostomus spp.

Gymnochanda species are gregarious by nature and ideally a group of 8-10 specimens should be the smallest purchased.

Sexual Dimorphism

Males develop extended dorsal and anal fin spines and posses red pigmentation in all unpaired fins, whereas females are basically colourless and lack extended fin spines.

Reproduction

Unrecorded.

NotesTop ↑

G. verae has appeared in the ornamental trade but is evidently delicate and therefore recommended only to experienced aquarists.

It can be distinguished from congeners by the following combination of characters: mature males with extended anal and second dorsal fins, the soft rays of both fins extending midway to the caudal fin, forming a triangular profile; elongated rays of the anal and second dorsal fins joined throughout their length by the interradial membrane; up to half of the distal part of both the anal and the second dorsal fins carmine red in life (hyaline when preserved); distal half of both upper and lower caudal-fin lobes carmine red in life (hyaline when preserved); female without any elongated fin rays or colour.

Gymnochanda species are characterised by their lack of scales and the presence of elongated dorsal and anal-fin rays in males.

The full diagnosis of the genus was modified slightly by Tan and Lim (2011) in order to accommodate G. verae, as follows: small ambassids with adult size not exceeding 32 mm SL. Body scale-less, translucent in life with complete but indistinct lateral groove. Mature individuals sexually dimorphic (note that this is not known in the case of Gymnochanda limi), mature males with one of the following modified fin characters: 1) anterior 1st to 4th soft rays of the anal and second dorsal fins produced into long filaments; 2) fin rays elongated but joined by interradial membranes; or 3) elongated second anal-fin spine. Females colourless with or without slight fin extensions. Preorbital with 2 to 4 large projecting serrae. Preoperculum strongly denticulate on the lower margin. Gill rakers long and slender, 12 to 16 on the lower branch of the first branchial arch

There are currently four described species but they are under-represented in museum collections and may have been overlooked in the past.

References

1. Tan, H. H. and K. K. P. Lim, 2011 - Zootaxa 3085: 55-62
   A new species of glass-perch from Belitung Island, Indonesia (Teleostei: Ambassidae: Gymnochanda).