Taxonomy & naming
Tatia marthae was described by Richard P. Vari and Carl J. Ferraris Jr. in 2013, one of the more recent additions to the driftwood catfish genus Tatia. It belongs to the family Auchenipteridae, the driftwood or wood catfishes, a wholly South American group distinguished among catfishes by internal fertilisation. The Catalog of Fishes treats Tatia marthae as the valid name, with no older synonym to correct — it has always been described in Tatia.
The genus name Tatia is taken from a local or vernacular name for small catfishes of this type; the species epithet marthae honours Martha Joynt, a Management Support Specialist at the Smithsonian National Museum of Natural History, in recognition of significant assistance she gave both authors during their work on the group.
Morphology
Tatia marthae has the slim, fusiform body typical of small Tatia — two dorsal spines and five dorsal soft rays, seven anal soft rays, and 35–36 vertebrae in the original description's counts. Like all driftwood catfishes it is scaleless, its skin naked rather than plated, which makes it more sensitive than a scaled fish to copper and many aquarium medications.
It is a genuinely tiny catfish: maximum recorded size is only about 1 in standard length, making it one of the smallest species in the entire order Siluriformes and smaller than almost any other catfish likely to appear in the hobby. The reported pattern is described as attractive, though the fish is rarely seen well enough in the aquarium to appreciate it, since it spends the great majority of daylight hours tucked out of sight.
Habitat
The species is known only from a small tributary of the Río Caura, itself a major southern tributary of the Río Orinoco in Venezuela — the Caura drainage is also the type locality for the species. This places it firmly in the Orinoco basin fauna of the Guiana Shield region, a landscape of blackwater and clearwater streams draining ancient, mineral-poor terrain.
Water in the Caura system runs warm, and Tatia marthae is generally kept and reported at 79–82 °F. Beyond that the original description and available notes do not give a fine-grained pH or hardness profile for the type locality, so specific figures should be treated as data-sparse rather than precisely known; as with many Tatia, avoiding extremes of hardness and pH is the practical guidance rather than a narrow target range.
Feeding
Tatia marthae is a nocturnal benthic omnivore and micro-predator. In the wild it forages the streambed after dark, picking over invertebrates, detritus and small prey items rather than actively hunting fish by day.
In the aquarium it accepts sinking pellets and frozen or prepared foods without difficulty, but because it is strictly a night forager it needs to be fed after the lights go out — offered food during the day in a lit tank, it is easily outcompeted or simply ignores it. Small portions timed to a two-to-three-minute feeding window at dusk match its natural rhythm better than a single daytime feeding.
Mating
As in other driftwood catfishes, mating in Tatia marthae is internal — a distinctive trait shared across the family Auchenipteridae and rare among catfishes generally. The male's anal fin is modified into an intromittent organ used to transfer sperm directly to the female during a brief pairing, rather than the eggs and milt being released together into open water.
The female then stores that sperm internally rather than laying fertilised eggs immediately. Reports place the delay at roughly 24 to 48 hours between mating and egg-laying, meaning a female can lay a fertile clutch even when no male is present at the time — a genuinely unusual reproductive strategy that sets Tatia and its relatives apart from almost every other catfish group in the hobby.
Breeding
Reproduction proceeds by internal fertilisation via the male's modified anal fin, with the female storing sperm and spawning independently afterward, typically into a cave or crevice among wood and cover rather than in the open. The genus as a whole is reported to have good breedability in captivity relative to most catfishes, since the mechanism does not require the elaborate triggers (flooding, hormone induction) that many other groups need.
Parental care beyond egg-laying is minimal to absent — once the female deposits her clutch there is no reported male guarding behaviour comparable to the bubble-nesting callichthyids, and specific first-hand aquarium spawning accounts for this particular species are scarce given how recently it was described and how rarely it is seen in the trade. Given the fish's tiny adult size and secretive habits, most keepers should expect incidental rather than deliberately managed spawns.
In the aquarium
Tatia marthae's headline care fact is its size: at a maximum of about 1 in standard length, this is one of the smallest catfish a hobbyist can keep, and there is no size trap in the usual sense — the risk here runs the other way, since a fish this small can be bullied, out-competed for food, or even eaten by tankmates many aquarists would consider perfectly peaceful. A small, quiet species-appropriate setup with fine-leaved plants, driftwood and leaf litter to hide in suits it far better than a general community tank.
Because it is scaleless it is medication-sensitive; treat with copper and other medications conservatively, as with loaches, puffers and true eels. It is strictly nocturnal and needs dense cover to feel secure during the day — expect to see very little of it except after dark or under red/blue night-viewing light. Warm water in the 79–82 °F range suits it. It lacks the large locking spines of bigger catfishes, but it should still be handled gently in a net or cup given its minute size and fragility.
Conservation
The IUCN Red List has not formally assessed Tatia marthae; its status is Data Deficient. This is unsurprising for a species described only in 2013 from a single small tributary of the Río Caura — there is no population data to support a status determination one way or the other.
Its entire known range sits within one drainage of the Orinoco basin in Venezuela, so any pressures on that specific tributary — deforestation, mining runoff or hydrological change in the wider Caura system, which has faced mining-related environmental concerns in recent years — are the relevant conservation context even though they have not been formally tied to this species. The aquarium trade for it is essentially negligible given its size and obscurity; there is no indication of commercial collection pressure.