White Cloud Mountain Minnow
First discovered at White Cloud Mountain (also known as Mount Baiyun or Baiyunshan) a few miles north of the city of Guangzhou, Guangdong Province, China and thought to be restricted to the surrounding Pearl River Delta region.
Unfortunately it has probably been extirpated from that locality; the ‘mountain’ is actually a collection of thirty or so peaks and is now a very popular tourist resort complete with cable car access, hotels and public parks. Between 1980 and 2001 the species went unrecorded in nature leading to fears of its extinction.
Since then a handful of relict wild populations have been rediscovered close to the type locality and at isolated spots in coastal Guangdong province (in the prefecture-level city of Shanwei) and Quang Ninh province, northeastern Vietnam. The latter shares a border with Guangxi province, China, and the fish were found in a coastal stream draining into the world famous Ha Long Bay.
A further, isolated population was discovered in 2007 on Hainan Island, Hainan province, which is separated from Guangdong by the 30 km wide Qiongzhou Strait (Chan and Chen, 2009). Questions regarding the genetic status of the Shanwei, Hainan, and Vietnamese populations have been raised as they appear to have been segregated for a considerable period of time meaning phylogenetic studies could yield interesting results.
It’s considered an endangered species by governmental agencies in China and features in the China Red Data Book of Endangered Animals, in which it is listed as a ‘second class state protected’ animal, but has not been evaluated by the IUCN at time of writing.
Reintroduction programmes using captive-bred fish have been implemented but we’ve been unable to obtain details as to their success or failure. This precarious conservation status does not affect the aquarium hobby because all the fish seen on sale are produced commercially.
Little published information exists but one of the populations rediscovered close to the type locality in Guangdong inhabits a sluggish, spring-fed mountain stream with clear, shallow water and dense growths of aquatic vegetation (Yi et al. 2004). Macropodus opercularis and introduced Gambusia affinis were the only other fish species recorded.
The Hainan Island fish occupy a clear, slow-moving coastal stream and its tributaries. The substrate is composed of sand, pebbles and leaf litter and even during the wet season the maximum water depth was only 23.6″/60cm.
They were observed swimming in schools in calmer zones and backwaters close to patches of dense, trailing marginal vegetation. The pH was 6.4 with low hardness values and plant species present included Blyxa japonica, Rotala rotundifolia, Ludwigia prostrata, Ceratopteris thalictroides and Limnophila sp. Other fishes included Puntius semifasciolatus, Misgurnus anguillicaudatus, Macropodus opercularis, and Channa gachua as well as non-native Gambusia and Oreochromis.
Maximum Standard Length
30 – 40 mm.
Aquarium SizeTop ↑
Minimum base dimensions of 45 ∗ 30 cm or equivalent are required.
Choice of décor is not especially critical though it tends to show better colouration in a heavily-planted set-up with a dark substrate. The addition of some floating plants, driftwood roots or branches, and leaf litter also seems to be appreciated and adds a more natural feel.
Filtration does not need to be particularly strong though it does seem to appreciate a degree of water movement and will also do well in a hill stream-type set-up.
Temperature: This species is subject to seasonal temperature fluctuations in nature and is most comfortable between 16 – 22 °C.
Permanent exposure to warmer conditions is likely to result in a shortened lifespan and in many countries or well-insulated homes it’s best-maintained without artificial heating year-round. In tests the wild fish from Hainan Island showed a reduced tolerance to cooler temperatures compared with tank-bred specimens, presumably due to their more southerly, i.e. tropical, distribution.
pH: 6.0 – 8.5
Hardness: 90 – 357 ppm
In the aquarium it’s easily-fed but the best condition and colours offer regular meals of small live and frozen foods such as bloodworm, Daphnia, and Artemia, alongside good quality dried flakes and granules, at least some of which should include additional plant or algal content.
Behaviour and CompatibilityTop ↑
Very peaceful indeed and an ideal resident of a well-maintained community set-up provided its temperature requirements are considered. Other species that enjoy comparable conditions include Pethia conchonius, P. padamya, ‘Puntius‘ semifasciolatus, and Macropodus opercularis (it occurs sympatrically with the latter two in nature).
In a stream-style tank it can also be combined with rheophilic species from genera such as Danio, Devario, and Garra as well as many loaches. It doesn’t really make a suitable companion for goldfish despite often being sold as such, however.
It’s a schooling fish by nature and ideally a group comprising at least 8-10 specimens should be purchased. Maintaining such numbers will not only make individuals less nervous but will result in a more effective, natural-looking display. Males will also display their best colours as they compete with one other for female attention.
Mature females are usually rounder-bellied and often a little larger than the slimmer, more colourful males.
Like many small cyprinids this species is an egg-scattering, continuous spawner that exhibits no parental care. That is to say when the fish are in good condition they will spawn often and when a group is maintained alone in a densely-planted, mature aquarium or outdoor container small numbers of fry usually start to appear without further intervention.
However if you want to maximise yield a more controlled approach is required. The adult group can still be conditioned together but a smaller aquarium should also be set up and filled with mature water. This should be very dimly lit and the base covered with some kind of mesh of a large enough grade so that the eggs can fall through but small enough so that the adults cannot reach them.
The widely available plastic ‘grass’-type matting can also be used and works well, as does a layer of glass marbles. Alternatively filling much of the tank with a fine-leaved plant such as Taxiphyllum spp. or spawning mops can also return decent results. The water itself should be of slightly acidic to neutral pH with a temperature towards the upper end of the range suggested above. An air-powered sponge filter or air stone(s) should also be included to provide oxygenation and water movement.
When the adults are well-conditioned and the females appear gravid one or two pairs should then be introduced, and spawning should take place the following morning. An alternative is to spawn the fish in a group with half a dozen specimens of each sex being a good number, although a larger aquarium may be necessary.
In either situation the adults will probably eat the eggs given the chance and should be removed after 2-3 days maximum. Eggs should hatch in 48-60 hours and the fry should be offered an infusoria-grade food once they can be seen swimming freely, continuing until they’re large enough to accept microworm, Artemia nauplii, dried products, etc.
One of the most ubiquitous species in the hobby and several ornamental strains are available including ‘long-finned’, ‘golden’, ‘albino‘, and ‘super red’, for which care is identical to that of the ‘standard’ fish. Unfortunately the degree of inbreeding amongst farm-bred stock has resulted in a situation whereby many of the fish available today are genetically weak and prone to disease or develop physical deformities.
We’ve also seen some of the more colourful forms mislabelled as Aphyocypris pooni, a name currently considered a junior synonym of T. albonubes, or A. lini, chosen as a replacement for A. pooni by Weitzman & Chan (1966) and representing an unrelated species.
T. albonubes was discovered by a Chinese scoutmaster named Tan Kam Fei in 1932 who passed some specimens on to a local fisheries station, and the director of the station chose to honour the collector by naming the newly-erected genus in his honour.
It remained monotypic until 2001 when T. micagemmae and T. thacbaensis were described from Vietnam. The former has been available in the trade for a number of years and is an excellent aquarium fish though it may be critically endangered in nature.
T. thacbaensis is somewhat more mysterious, having been described by two Vietnamese authors in the first volume of a series of books on native freshwater fish species. This is written entirely in Vietnamese, is now out of print and only a small number of copies were produced.
A fourth species, currently known only as T. sp. ‘Vietnam’ appeared in the aquarium trade during 2010 and has been occasionally available in extremely limited numbers.
The species available to hobbyists are easy to tell apart. T. albonubes is noticeably larger than T. micagemmae and T. sp. ‘Vietnam’, and exhibits an overall reddish-brown colouration in the body that is lacking in the other two whilst also possessing a relatively thinner dark lateral body stripe below the eye-catching lighter stripe.
In T. micagemmae the ventral and anal fins are reddish, whereas the same fins are bright yellow in T. sp. ‘Vietnam’.
Diagnostic characters for genus members include presence of cornified tubercules on the snout posterior to the premaxila in males, and confluent narial openings.
Less clear is the phylogenetic position of the grouping within the family Cyprinidae. It has been considered closely related to the genera Danio or Rasbora but recent studies, notably that of Fang et al. (2009) have suggested it to be more analagous withTinca tinca (the common tench) and the subfamily Acheilognathinae, better known as the bitterlings.
The results also suggested that T. micagemmae is the parent species of the group in evolutionary terms with T. albonubes its younger relative.
- Chan, B.P.L., and X-L Chen, 2009 - Zoological Research 30(2): 209–214
Discovery of Tanichthys albonubes Lin 1932 (Cyprinidae) on Hainan Island, and notes on its ecology.
- Fang, F., M. Norén, T. Y. Liao, M. Källersjö, and S. O. Kullander, 2009 - Zoologica Scripta 38(1): 1-20
Molecular phylogenetic interrelationships of the south Asian cyprinid genera Danio, Devario and Microrasbora (Teleostei, Cyprinidae, Danioninae).
- Liang, X-F, G-Z. Chen, X-L. Chen, and P-Q. Yue, 2007 - Environmental Bi0logy of Fishes 82(2): 177-178
Threatened fishes of the world: Tanichthys albonubes Lin 1932 (Cyprinidae).
- Rüber, L, M. Kottelat, H. H. Tan, P. K. L. Ng, and R. Britz, 2007 - BMC Evolutionary Biology London 7: 1-10
Evolution of minituarization and the phylogenetic position of Paedocypris, comprising the world's smallest vertebrate.
- Yi, Z-S., X-L. Chen, J-X. Wu, S-C. Yu, and C-E. Huang, 2004 - Zoological Research 25(6): 551-555
Rediscovering the wild population of white cloud mountain minnows (Tanichthys albonubes Lin) on Guangdong Province.