Datnioides pulcher (KOTTELAT, 1998)

Siamese Tiger Perch

SynonymsTop ↑

Coius pulcher Kottelat, 1998

Etymology

Datnioides: from the genus name Datnia and Ancient Greek εἶδος ‎(eîdos), meaning ‘form, likeness’.

pulcher: from the Latin pulcher, meaning ‘beautiful’.

Classification

Order: Perciformes Family: Datnioididae

Distribution

Recorded from the Mae Klong and Chao Phraya river systems in Thailand, the middle and lower Mekong basins in Thailand, Laos, Cambodia, and Vietnam, and Đồng Nai watershed in Vietnam. It has been locally extinct in Thailand since the 1990s, with populations greatly reduced elsewhere.

Type locality is ‘Bung Boraphet, Thailand’, corresponding to the large freshwater lake also known as Bueng Boraphet in the Chao Phraya River basin, Nakhon Sawan province, central Thailand.

Habitat

An exclusive inhabitant of large, deep, typically lowland freshwater rivers, and not thought to enter brackish environments. It has been collected from flooded forests during the annual wet season.

The massive decline in wild populations, hypothesised to be in excess of 90% since the mid-1980s, is thought to have been caused by a variety of factors, including habitat alteration due to construction of dams and other infrastructure, removal of riparian vegetation, and urban pollution, plus over fishing for both human consumption and the aquarium trade. It is currently considered ‘Critically Endangered’ by the IUCN.

Maximum Standard Length

350 – 400 mm.

Aquarium SizeTop ↑

Suitable only for public installations or the very largest private aquaria.

Maintenance

Juveniles and subadults should be provided with a well-decorated, planted aquarium with driftwood roots and branches. Larger individuals are relatively unfussy, although some surface cover in the form of floating or overhanging vegetation or branches is appreciated. The addition of marine salt is not required at any life stage.

Datnioides spp. typically produce a lot of waste so the use of large external filters is essential. If possible buy units with built in heaters or at least fit a sturdy heater-guard since adults have been known to damage submerged equipment. Sump systems also work well, and the heater can be housed within.

They do not travel well and can be tricky to stabilise post-import, often refusing to feed and continuously exhibiting a colour pattern indicative of stress but also displayed at night. In D. pulcher the entire body darkens, and the body bars become less distinct.

Water Conditions

Temperature: 20 – 28 °C

pH: 5.5 – 7.5

Hardness: 36 – 268 ppm

Diet

An efficient, largely piscivorous, predator with highly protrusible mouthparts. In the aquarium, juveniles can be offered chironomid larvae (bloodworm), small earthworms, chopped prawn, and suchlike, while adults will accept strips of fish flesh, whole prawns, mussels, live river shrimp, larger earthworms, etc. Older individuals do not require feeding on a daily basis, with 2-3 times per week sufficient.

This species should not be fed mammalian or avian meat such as beef heart or chicken since some of the lipids contained in these cannot be properly metabolised by the fish and may cause excess fat deposits and even organ degeneration. Similarly, there is no benefit in the use of ‘feeder’ fish such as livebearers or small goldfish, which carry with them the risk of parasite or disease introduction and tend not have a high nutritional value unless properly conditioned beforehand.

Behaviour and CompatibilityTop ↑

Can be maintained alongside similarly-sized fishes if sufficient space is available, but might be intimidated by territorial or otherwise competitive species.

Although juveniles may form groups, adults are not gregarious and tend to respond aggressively to conspecifics and similarly-shaped fishes. They are best maintained singly or in a group of 5 or more individuals.

Sexual Dimorphism

Unknown.

Reproduction

Unrecorded. Captive breeding efforts are apparently underway in Thailand and Cambodia, but with little success to date.

NotesTop ↑

In aquarium literature this species is also referred to as ‘Siamese tiger fish (ST)’, ‘Cambodian tiger fish (CT), ‘golden datnoid’, ‘widebar datnoid’, and ‘widebar dat’. The common name of ‘tiger fish’ is also used in reference to the African alestid genus Hydrocynus, therefore the more appropriate ‘tiger perch’ was suggested by Roberts and Kottelat (1994).

It is highly sought after by aquarists, and the congener D. microlepis is sometimes sold as D. pulcher in order to raise prices.

D. pulcher is distinguished from all congeners by its unique colour pattern comprising usually 4, exceptionally 5, regular, dark, broad bars on body (vs. up to 7 bars sometimes with 1-4 smaller bars between in D. polota; 6-7 distinct wide bars in D. microlepis; 4 thin bars sometimes with a single partial bar in D. undecimradiatus; 4-6 wide bars with diffuse margins in D. campbelli); bar 1 from nape through opercle onto thoracic region and across ventral surface of the body; bar 2 from base of dorsal spines 2-5 to slightly in front of anal fin origin; bar 3 starts at base of dorsal spine 9 to base of dorsal ray 2, and ends at base of anal rays 2-6; bar 4 on posterior half of caudal peduncle; body scales small, with 70-100 in the lateral series (vs. large, 40-60 in the lateral series in D. polota and D. campbelli); predorsal profile almost straight (vs. distinctly concave in D. polota and D. campbelli).

It is easily confused with D. microlepis, and these two were considered conspecific prior to 1998. In principle they can be separated by the number of dark body bars (4-5 in D. pulcher, 6-7 in D. microlepis), but this observation appears to be based solely on D. microlepis specimens from Borneo with the colour pattern of Sumatran and Malaysian populations undocumented. Adult individuals can usually be separated on the basis of base body colour, which tends towards orangey-brown in D. pulcher, dirty yellowish-grey in D. microlepis.

Following Kottelat (2001), the genus Datnioides is diagnosed by the following combination of characters: second spinous anal-fin ray longer than the first and third rays; presence of fine teeth and 2-3 blunt spines on the edge of the opercle; 50+ lateral line scales; barred colour pattern.

Members were included in the genus Coius during the 1990s, but Coius is now considered to be a synonym of the genus Anabas (Kottelat, 2000). The former family name Coiidae is thus a synonym of Anabantidae, and Datnioides species comprise the monotypic family Datnioididae. The genus has also been included in the marine tripletail family Lobotidae in the past, and preliminary phylogenetic analyses suggest a close relationship these two groups.

References

1. Kottelat, M., 1998 - Ichthyological Exploration of Freshwaters 9(1): 1-128
   Fishes of the Nam Theun and Xe Bangfai basins, Laos, with diagnoses of twenty-two new species (Teleostei: Cyprinidae, Balitoridae, Cobitidae, Coiidae and Odontobutidae).
2. Freyhof, J., D. V. Serov and T. N. Nguyen, 2000 - Bonner Zoologische Beiträge 49(1-4): 93-99
   A preliminary checklist of the freshwater fishes of the River Dong Nai, South Vietnam.
3. Kottelat, M., 2000a - Journal of South Asian Natural History 5(1): 83-90
   Notes on taxonomy, nomenclature and distribution of some fishes of Laos.
4. Kottelat, M., 2013 - Raffles Bulletin of Zoology Supplement 27: 1-663
   The fishes of the inland waters of southeast Asia: a catalogue and core bibiography of the fishes known to occur in freshwaters, mangroves and estuaries.
5. Kottelat, M., 2000b - Journal of South Asian Natural History 5(1): 91-94
   The type species of the genus-group names Coius Hamilton, 1822 and Datnia Cuvier, 1829 and the type-genus of the family-group name Datnioididae Bleeker, 1858.
6. Kottelat, M., 2001 - WHT Publications, Colombo: 1-198
   Fishes of Laos.
7. Rainboth, W. J., 1996 - Rome, FAO: 1-265
   FAO species identification field guide for fishery purposes. Fishes of the Cambodian Mekong.
8. Roberts, T. R. and M. Kottelat, 1994 - Ichthyological Exploration of Freshwaters 5(3): 257-266
   The Indo-Pacific tigerperches, with a new species from the Mekong basin (Pisces: Coiidae).