Taxonomy & naming
Rasbora laticlavia was formally described by Siebert and Richardson in 1997 and is placed in the family Danionidae (formerly treated as a subfamily of Cyprinidae). The Catalog of Fishes (Eschmeyer, the authority for valid names) records the combination as Rasbora laticlavia Siebert & Richardson, 1997. It is assigned to the argyrotaenia species group, a cluster of larger, more elongate rasboras distinguished in part by a prominent lateral stripe.
The genus Rasbora as currently circumscribed has undergone considerable revision since the 1990s. Several genera previously synonymised with Rasbora or carved directly from it — Boraras, Trigonopoma, Brevibora, Kottelatia and Rasboroides among them — have been reinstated or erected, and the celestial pearl 'galaxy rasbora' was transferred to Danio. Rasbora laticlavia itself remains in Rasbora under the current Catalog of Fishes treatment, and no subsequent transfer has been published. ITIS places it in Danionidae as a valid species.
The specific epithet laticlavia is Latin, from latus (broad) and clavus (stripe or nail), alluding to the broad lateral band that runs along the flank — a reference echoed across the argyrotaenia group, whose name likewise means 'silver band.'
Morphology
Rasbora laticlavia is a relatively large rasbora, with a maximum recorded standard length of 4.5 in according to FishBase. Like other members of the argyrotaenia group it has an elongate, moderately compressed body, a terminal to slightly upturned mouth suited to feeding in mid-water or at the surface, and the prominent lateral stripe that characterises the group.
Data on detailed meristics and colouration from the wild are sparse in the available literature. The species presumably shows the typical rasbora build — a streamlined, fusiform body with a forked caudal fin and modest scaling — in keeping with a fish that occupies riffled, flowing stream environments. Sexual dimorphism has not been specifically documented in the available sources; as in most Rasbora, females are likely deeper-bodied when gravid.
Habitat
Rasbora laticlavia is endemic to Kalimantan, the Indonesian portion of Borneo, where it occupies small to moderate-sized freshwater streams. Its habitat is characterised by good pool-riffle structure, pebbly or sandy substrates and an abundance of fallen tree trunks and large woody debris — features consistent with intact or near-intact lowland forest streams of the Sundaland ecoregion.
No precise water chemistry parameters for the species' native streams are recorded in FishBase or the other available sources, though the clear, structured stream environment suggests water that is cool relative to peat-swamp blackwaters, likely soft to moderately soft and circumneutral to mildly acidic in reaction, reflecting the granite and sedimentary geology of interior Kalimantan. The presence of riffle structure and pebbly substrate indicates good oxygenation and moderate flow rather than the still, tannin-rich conditions of coastal peat-swamp habitats.
Feeding
Like the great majority of Rasbora, R. laticlavia is presumed to be an opportunistic omnivore, taking small invertebrates — aquatic insect larvae, small crustaceans, fallen terrestrial insects — as well as algae and organic detritus. Its stream habitat, with riffled water over pebbly substrates and submerged wood, would provide abundant invertebrate prey year-round.
No published dietary study specific to R. laticlavia has been located. In the aquarium it can be expected to accept the full range of prepared and live foods appropriate for a cyprinid of its size, including quality pellets or granules, frozen bloodworm, daphnia and brine shrimp. Its relatively large size means it will consume food items that smaller rasboras cannot.
Mating
Rasbora laticlavia is an egg-scattering, non-guarding spawner in keeping with the biology of the genus and family. No field study of its reproductive behaviour has been published, but Rasbora species typically spawn opportunistically in response to rising water levels and increased flow associated with seasonal rains. A driving male pursues a gravid female through the water column or among vegetation, and eggs and milt are released together during brief parallel contact.
There is no pair bond, no nest construction and no parental involvement beyond the moment of spawning. Adhesive or weakly adhesive eggs settle on the substrate, among plant roots or leaf litter, and are subsequently ignored — or actively eaten — by the adults.
Breeding
No captive breeding record for Rasbora laticlavia has been documented in the available sources, reflecting its status as a rarely traded and seldom-kept species. Based on the biology of the argyrotaenia group and large-bodied Rasbora in general, the standard approach for related species would apply: a separate spawning vessel with fine-leaved plants or a mesh bottom to protect the eggs, well-conditioned adults, a slight temperature increase, and a partial water change to trigger spawning.
Eggs scattered over the substrate or among vegetation would need to be protected from the adults immediately after spawning. At tropical stream temperatures hatching would be expected within two to three days, with free-swimming larvae appearing a few days later and accepting very fine live foods at first. Data on clutch size, incubation period and larval development remain undocumented for this species.
In the aquarium
Rasbora laticlavia is rarely encountered in the hobby, and no established aquarium literature exists for it. Its relatively large maximum size (over 4.5 in SL) means it requires a spacious aquarium — a tank of at least 47 in in length would be the minimum for a small group. As a fish of riffled, well-oxygenated streams, it would benefit from good filtration and some current rather than the still, acidic conditions suited to peat-swamp rasboras.
In the absence of specific data, water parameters consistent with clean, moderately soft, circumneutral Bornean stream water — around 72–79 °F, pH 6.5–7.5 — represent a reasonable starting point. Being an active schooling fish, R. laticlavia should be kept in groups; it is unlikely to harass other robust species of comparable size. Its scarcity in trade means it is most likely to be encountered as wild-caught specimens from specialist importers of Bornean stream fishes.
Conservation
Rasbora laticlavia is assessed as Least Concern (LC) on the IUCN Red List, with the assessment dated 16 January 2019 (IUCN Red List version 2022.2). The assessment reflects an absence of evidence of major range-wide decline at the time of evaluation, though the species is known only from Kalimantan and its distribution within the island has not been fully characterised.
The broader context for Bornean freshwater fishes is one of significant and ongoing habitat loss. Lowland forest streams of the kind R. laticlavia inhabits are under sustained pressure from logging, conversion to oil-palm plantations, mining and associated sedimentation and water-quality degradation. Kalimantan has experienced some of the fastest rates of primary forest loss in Southeast Asia over recent decades. Although the IUCN assessment did not find sufficient evidence to trigger a threatened category, the species' endemism to Kalimantan and its dependence on structurally intact stream habitats make it inherently vulnerable to continued land-use change.