Leptodoras linnelli

Elongate Mouse Catfish

Classification

Doradidae

Distribution

Various river drainages of northern South America, including the Rio Casiquiare and Upper Rio Orinoco in Venezuela, Rio Essequibo, Rio Demerara and Rio Araguari in Guyana and Rio Uatumã, Rio Tacutu and Rio Demini in northern Brazil.

Habitat

Usually found over sandy substrates in deeper, flowing sections of rivers.

Maximum Standard Length

9.2″ (23cm).

Aquarium SizeTop ↑

An adult specimen is going to need a tank measuring at least 48″ x 18″ x18″ (120cm x 45cm x 45cm) – 255 litres.

Maintenance

Replication of this species‘ natural habitat would be relatively easy. A substrate of fine sand, with perhaps the odd rounded boulder or driftwood branch for effect and cover is all that is required. Filtration should be quite powerful as this fish prefers a degree of flow through its tank, and is sensitive to deteriorating water quality. An external canister filter with the outlet positioned so that water flows down the length of the tank is probably the best option. As it naturally inhabits the bottoms of deep rivers where little sunlight penetrates, avoid using very bright lighting on the setup. In dimmer conditions it will be much more active and outgoing. Floating plants can greatly assist in this respect.

Water Conditions

Temperature: Prefers cooler water than many related species, in the range 64 – 72°F (18 – 22°C).

pH: 5.8 – 7.0

Hardness: 5 – 18°H

Diet

Generally unfussy. Dried catfish pellets, algae wafers and granular foods are all accepted, but live and frozen foods should also form a good proportion of the diet. It’s a good idea to add food to the aquarium just before lights out during the acclimitisation period, as it usually feeds during the hours of darkness until it feels settled.

Behaviour and CompatibilityTop ↑

Totally unaggressive, although very small tankmates may be eaten. It’s an excellent choice for the peaceful community of slightly larger South American species that appreciate flowing water. Any of the various Hemiodus or Triportheus species, as well as many Loricariids are excellent choices for a biotope style tank. More placid cichlids, such as Geophagus, Satanoperca, Heros or Uaru species can also work well.

Like most Doradids, L. linnelli occurs in schools in nature and fares better when in the company of its own kind. Buy as many as your tank will house comfortably.

Sexual Dimorphism

Unconfirmed, although sexually mature females are likely to be broader bodied than males.

Reproduction

Unreported in the hobby.

NotesTop ↑

The genus Leptodoras currently contains 10 species, none of which are particularly well known in the hobby. There is little published information regarding the genus, and its members are seldom exported for the aquatic trade.

L. linnelli is no exception, usually only turning up as bycatch among shipments of other species such as Opsodoras leporhinus or Hassar orestis. According to Fishbase, it can be distinguished from all other members of the genus except L. acipenserinus by the presence of a thin, ridge-like growth extending outwards from the front of the adipose fin approximately half way to the dorsal fin. Apparently it can also be told apart from L. acipenserinus by a slightly longer predorsal distance (approximately 35.5-38.7% of the total length of the fishes body), an incomplete inner gill flap, less (74 – 81) midlateral plates, the shape of the anal fin, the length of the pectoral spines and also the structure of the “teeth” that run along these spines (these are highly backward-facing along the lower edge of the spine, becoming less so towards the tip. Their size along the lower half of the spine is roughly uniform, and the last “tooth” is usually close to the tip).