Datnioides campbelli

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

campbelli: named in honour of Flight-Lieutenant Stuart Campbell, who collected the type series.

Apparently restricted to the southern portion of New Guinea, between the Lorentz River in Papua province, Indonesia, and Kikori River in Gulf province, Papua New Guinea. The majority of records pertain to the lower Fly River basin in Western province, southwestern Papua New Guinea.

Type locality is given erroneously as 'Upper Sepik River, New Guinea', since the types were actually collected from the Fly River (Allen & Coates, 1991)[2].

This species is euryhaline. In the Lower Fly River it has been collected from brackish tidal creeks, while in the middle and upper parts of the basin it inhabits large tributaries and swamps and has been recorded at least 900 km from the sea.

An aquarium with base dimensions of 210 ∗ 60 cm84 ∗ 24 in should be the minimum considered.

Juveniles and subadults should be provided with a well-decorated aquarium with driftwood branches or mangrove roots. Larger individuals are relatively unfussy, although some surface cover in the form of floating or overhanging vegetation or branches is appreciated. This species can survive in medium-to-hard freshwater or brackish conditions.

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. campbelli the body darkens considerably and the vertical body bars become indistinct.

An efficient predator with highly protrusible mouthparts, feeding chiefly on smaller fishes and crustaceans. 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.

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 when adult 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.

Unknown.

Unreported.

In aquarium literature this species is also known as 'Irian tiger fish', 'Papua tiger fish', 'New Guinea tiger fish (or 'NGT')', 'New Guinea datnoid', 'New Guinea dat', or simply 'NGT'. It is rarely traded and normally expensive when available. 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)[7].

D. campbelli is distinguished from all congeners by the following combination of characters: base body colour bright golden yellow (vs. white or silvery to yellowish or orange-brown in all other Datnioides species); colour pattern comprising 4-6 wide dark bars with diffuse margins (vs. up to 7 bars, sometimes with 1-4 smaller bars between in D. polota; 6-7 wide bars in D. microlepis; 4-5 wide bars in D. pulcher; 4 thin bars sometimes with a single partial bar in D. undecimradiatus); predorsal profile distinctly concave (vs. almost straight in D. microlepis, D. pulcher and D. undecimradiatus); 15-17 rakers on the first gill arch (vs. 20-23 in D. polota, 18-21 in C. microlepis); usually 10 branched anal-fin rays (vs. 9 in D. polota); body scales large, with 42-43 in the lateral series (vs. small, 70-100 in the lateral series in D. microlepis, D. pulcher and D. undecimradiatus); 11+13 vertebrae (vs. 10+14 in congeners).

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)[6]. 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.