Barbucca diabolica ROBERTS, 1989

Etymology

diabolica: in allusion to the glowing red eyes and ‘spiked’ tail characteristic of the species.

Classification

Barbuccidae

Distribution

Most of the type series was collected from a series of tributaries between the settlements of Sintang and Putussibau in the upper-middle Sungai (river) Kapuas basin, Kalimantan Barat (West Kalimantan), Indonesian Borneo , although a single specimen originated from Johor state, Peninsular Malaysia.

A possible undescribed member of the genus has been discovered in southern and eastern Thailand and one or more representatives can also be found in Sumatra.

The group is quite poorly-studied at present but it’s been suggested that the Malaysian populations may also turn out to represent separate species eventually.

Habitat

Not much information is available – the Bornean type specimens were all found in small forest streams but no further details are given.

A 1997 survey of fish species diversity resulted in the discovery of a population in the Khao Soi Dao Wildlife Sanctuary in Chanthaburi Province, Thailand, a mountainous, forested area covering almost 800 square kilometres.

Some of the other species found there (but not necessarily inhabiting the same habitats) include Garra cambodgiensis, Mystacoleucus marginatus, Oreichthys parvus, ‘Puntius‘ binotatus, P. partipentazona, Danio albolineatus, Esomus metallicus, Rasbora borapetensis, R. trilineata, Pangio myersi, Acanthopsoides gracilentus, Lepidocephalichthys berdmorei, a Serpenticobitis species, Homalopteroides smithi, Nemacheilus binotatus, N. platiceps, Pseudomystus siamensis, Glyptothorax spp., Parambassis siamensis, Betta prima, Trichopodus trichopterus and Tetraodon cambodgiensis.

Given its characteristic swimming behaviour (see ‘Notes’) it’s unlikely to inhabit major river channels or areas of open substrate and is probably restricted to marginal zones or areas where rocks, boulders, driftwood or leaf litter collect.

Maximum Standard Length

40 – 50 mm.

Aquarium SizeTop ↑

An aquarium with base dimensions of 60 ∗ 30 cm or equivalent is recommended.

Maintenance

To see it at its best furnish the tank with a sand/gravel substrate and add some water worn rocks of varying sizes arranged to form plenty of nooks, crannies and overhangs.

Driftwood roots, branches and aquatic plants can be added as well with species able to grow attached to the décor such as Microsorum pteropus, Anubias spp. and many mosses being particularly suitable. Lighting can be quite bright to aid the growth of aufwuchs which the fish appear to enjoy combing for food items.

In set-ups with less water flow a few handfuls of leaf litter can look very effective and these should be allowed to decompose fully in the tank as the micro-organisms colonising them can provide a valuable food source for small fishes, plus beneficial chemicals may be released as by-products of the process.

Like many fishes that hail from running waters it’s intolerant to accumulation of organic wastes and requires spotless water in order to thrive. For this reason it should never be introduced to biologically immature set-ups and adapts most easily to stable, mature aquaria.

Provided oxygenation is adequate water movement is unimportant though this species is also proven to do well in a river tank-style arrangement. In terms of maintenance weekly water changes of 30-50% tank volume should be considered routine.

Water Conditions

Temperature: 20 – 25 °C

pH: 5.5 – 7.5

Hardness: 18 – 179 ppm

Diet

Little is known of this species‘ natural diet although presumably it feeds on small crustaceans, insect larvae and other invertebrates.

In the aquarium it’s proven to accept both dried foods and live or frozen Artemia nauplii, Cyclops, etc. but anything offered must be of a sufficiently small grade.

Behaviour and CompatibilityTop ↑

Not especially robust and should not be kept with much larger or more competitive fishes. Miniature schooling cyprinids such as Boraras, Microdevario, smaller Danio or Rasbora species make good tankmates and if geography isn’t an issue many similarly-sized characins and livebearers should also work.

It can be protective of the area in which it’s currently foraging in but aggression is limited to short chasing attacks rather than biting, and intruders aren’t pursued into open water.

In a tank with lower water flow other substrate-dwelling loaches could include Pangio or Acanthopsoides spp. while in hill stream conditions many Gastromyzon, Pseudogastromyzon and Homaloptera are suitable.

Some members of the families Botiidae, Cobitidae and Nemacheilidae are also ok but proper research is essential as some can be excessively aggressive, territorial or simply grow too large. It’s also proven to co-exist peacefully with open water-dwelling Yunnanilus species and small freshwater shrimp of the genus Neocaridina.

Like many loaches it’s loosely territorial towards conspecifics but seems to require their presence to truly thrive. A group of six or eight specimens should be the smallest considered.

Sexual Dimorphism

According to Roberts (1989) both sexes possess tubercules on the caudal peduncle which extend above and in front of the anal fin, a feature seen in some other balitorid genera.

Both sexes can also exhibit tuberculation on the gill covers but mature males display a patch of very small tubercules around the base and rear of the eye, described by Roberts (1989) as ‘slightly concave, or hook-shaped’.

Reproduction

No records exist.

NotesTop ↑

Barbucca spp. are uncommon in the aquarium trade but available periodically. There exist several undescribed species and it’s possible that more than one has been exported, although to date only B. diabolica is officially recognised.

Most of the fish we’ve seen possess red eyes (when viewed at certain angles), unique tuberculation and six dark body stripes as mentioned in Roberts’ description although there are exceptions in the latter character at least (see images).

Barbucca spp. also exhibit a unique style of swimming, maintaining near-continuous belly contact with solid surfaces, and often swim in an inverted or vertical position if plants or other décor allow. They rarely venture into the water column and are thus commonly referred to as ‘scooter’ loaches.

The genus has long been considered related to nemacheilid loaches and was placed into the old grouping Nemacheilinae by Roberts (1989) and several subsequent authors.

Details of its phylogenetic position remained unclear until 2007, when the results of an analysis grouped it alongside balitorids of which members of Pseudogastromyzon, Vanmanenia, Beaufortia, Homaloptera and Balitora were included in the study.

Barbucca spp. exhibit several morphological peculiarities and Kottelat (2012) erected the new family Barbuccidae to accommodate them.

Barbuccidae is distinguished from other Cobitoidea families by mouth structure with members possessing a smooth, fleshy upper lip which may or may not have a median notch. The lower lip runs continuous with the upper and is  fleshy with a median interruption, and a thick,  fleshy barbel-like projection along its posterior edge.

The skin of the throat between the median extremities of the lower lip forms a fleshy, triangular lobe, with a soft, thin, compressed projection orientated perpendicular to body. There are two pairs of rostral barbels and one pair of maxillary barbels withy all barbels possessing rings of small projections. The lower jaw is ‘exposed’.

The other main difference between Barbuccidae and other loach families is the shape of the swim bladder (aka gas bladder) capsule. In Cobitidae this is a single globulous structure, while in Botiidae and Vaillantellidae it’s incompletely formed.

In the families Nemacheilidae, Balitoridae, Gastromyzontidae (Sawada, 1982), Serpenticobitidae (Nalbant, 2001) and Ellopostomatidae the capsule comprises two smaller chambers connected to each other posteriorly and forming a canal referred to as the ‘manubrium’ located around the duct which connects the two halves of the anterior swim bladder chamber.

In Ellopostoma spp. the manubrium does not form a complete tube but comprises a bony lamina around the ventral portion of the connective duct, while in Barbuccidae it’s absent entirely and the duct exposed.

Other distinguishing characters for Barbuccidae include: body short, compact, and marked with vertical bars; head small, snout blunt, with large, oval-shaped, dorso-laterally orientated eyes; anterior nostril located at the tip of a short tube; posterior nostril located at base of tube and adjacent to eye orbit; caudal-fin emarginate; dorsal-fin origin slightly anterior to pelvic-fin origin; pectoral and pelvic fins are orientated laterally, and each has only a single simple ray; presence of large tubercles  on lower flank above anal-fin (number and distribution variable depending on species).

References

1. Roberts, T. R., 1989 - Memoirs of the California Academy of Sciences 14: 210 p.
   The freshwater fishes of Western Borneo (Kalimantan Barat, Indonesia).
2. Kottelat, M., 1990 - Verlag Dr. Friedrich Pfeil, München, Germany. 262 p.
   Indochinese nemacheilines. A revision of nemacheiline loaches (Pisces: Cypriniformes) of Thailand, Burma, Laos, Cambodia and southern Viet Nam.
3. Kottelat, M., 2012 - Raffles Bulletin of Zoology Supplement 26: 1-199
   Conspectus cobitidum: an inventory of the loaches of the world (Teleostei: Cypriniformes: Cobitoidei).
4. Sontirat, S., S. Tunchareon and Y. Soothornkit, 2006 - Proceedings of 44th Kasetsart University Annual Conference: Fisheries, Bangkok (Thailand), p. 60-67.
   Fish species diversity in the areas of National Parks and Wildlife Sanctuaries in the five eastern provinces of Thailand.
5. Tang, Q., H. Liu, R. Mayden and B. Xiong, 2006 - Molecular Phylogenetics and Evolution 39(2): 347-357
   Comparison of evolutionary rates in the mitochondrial DNA cytochrome b gene and control region and their implications for phylogeny of the Cobitoidea (Teleostei: Cypriniformes).
6. Šlechtová, V., J. Bohlen and H. H. Tan, 2007 - Molecular Phylogenetics and Evolution 44(3): 1358-1365
   Families of Cobitoidea (Teleostei; Cypriniformes) as revealed from nuclear genetic data and the position of the mysterious genera Barbucca, Psilorhynchus, Serpenticobitis and Vaillantella.