Gulf Saratoga

Fertilized eggs are carried in the mouth of the female. Eggs hatch in 1-2 weeks. Larvae, with their enlarged yolk sac, are kept in or close to the mouth for another 4 or 5 weeks. Young fish commence feeding, primarily on microcrustaceans, at a size of 2-3 cm, well before the yolk sac is entirely resorbed. Become independent at a length of 3.5-4.0 cm.

Dorsal spines (total): 0; Dorsal soft rays (total): 20 - 24; Analspines: 0; Analsoft rays: 28 - 32

Occurs in still waters of streams and swamps where it is usually seen near the surface or close to shore among aquatic vegetation. Young feed primarily on microcrustaceans (Ref. 2847). Primarily a surface feeder, feeding on a variety of terrestrial and aquatic insects, small fishes, crustaceans, and some plant material (Ref. 44894).

Adults occur in still waters of streams and swamps where it is usually seen near the surface or close to shore among aquatic vegetation (Ref. 2847, 44894). Solitary, territorial and spawn prior to the wet season when surface water temperatures approach 30°C (Ref. 44894). Young feed primarily on microcrustaceans (Ref. 2847). Primarily a surface feeder, feeding on a variety of terrestrial and aquatic insects, small fishes, frogs, crustaceans, and some plant material (Ref. 44894). Mouthbrooders (Ref. 56180). Maximum weight reported in Ref. 5259 may be 12.27 kg (W. Lau, pers. Comm. 07/05). Important food fish (Ref. 58511) and a valuable aquarium fish (Ref. 83518).

fisheries: of no interest; aquaculture: commercial; gamefish: yes; aquarium: commercial

Scleropages jardini (Kent, 1892)

USNM 217046, Fly 75–4, 2: 257–405 mm.

USNM 217047, Fly 75–6, 1: 407 mm.

USNM 217048, Fly 75–16, 1: 110 mm.

USNM 217049, Fly 75–20, 1: 213 mm.

Lake (1971:17) recognizes two species of Scleropages in the Australian Region: S. leichardti Günther, 1864, confined to the Fitzroy River system in southern Queensland, and S. jardini in central-southern New Guinea and in some Australian rivers flowing into the Gulf of Carpentaria and the Timor Sea. According to Lake and Midgley (1970) S. leichardti are essentially insectivorous and “have straight backs and in this attitude their mouths are in a superior position” whereas jardini feed more on crustaceans and “have a bowed back…their mouth pointing more forward than upward”; they also state, but without providing data or further explanation, that there are differences in meristics and coloration. According to Lake (1971) S. leichardti tolerates colder temperatures than S. jardini, which he refers to as the “northern spotted barramundi.”

Scleropages jardini is the only fish species inhabiting fresh water in New Guinea that has been considered to be a primary division freshwater fish, all of the others clearly belonging to secondary or peripheral division freshwater groups. The geographical distribution of Scleropages, with two species in the Australian Region and a closely related third species in Thailand, Malaya, Sumatra, and Borneo, suggests a relatively late marine dispersal. I do not know of any published reports on salinity tolerance of Osteoglossidae. At my request Alfred D. Castro of Steinhart Aquarium in San Francisco tested a 400-mm adult specimen of the Southeast Asian Scleropages formosus (Müller and Schlegel, 1844) for salinity tolerance. From 21 June to 18 September 1977, salinity was gradually increased from 0 to 8 parts per thousand (salinity of undiluted sea water is usually 35–38 parts per thousand) without any apparent effect on the fish. On 22 September salinity was increased from 7 ppt to 8 ppt, and its coloration lightened dramatically but it continued feeding normally and no other effects were noted. From 25 September to 13 October, salinity was gradually increased to 14 ppt, at which point the fish stopped feeding. After one week at 14 ppt it still had not fed; from 13 October to 19 October, salinity was gradually lowered to 9 ppt, and on 23 October feeding resumed. From 23 October to 30 October, salinity was increased to 13.5 ppt, and feeding stopped again. From 30 October to 30 November the fish was kept at 9 ppt. From 30 November to 12 December salinity was increased to 18 ppt, at which point the fish lost equilibrium and turned belly-up. Salinity was rapidly reduced to 10 ppt and then 5 ppt, but the fish did not recover and died on 19 December 1977. These results indicate a greater salinity tolerance than might be expected for a primary freshwater fish, but it should be kept in mind that very little experimentation has been done on this topic.

Scleropages jardinii, the Gulf saratoga, Australian bonytongue , Pearl arowana or northern saratoga, is a freshwater bony fish native to Australia and New Guinea, one of two species of fishes sometimes known as Australian arowana, the other being Scleropages leichardti. It has numerous other common names, including northern saratoga, toga and barramundi (not to be confused with the barramundi perch, Lates calcarifer). It is a member of the subfamily Osteoglossinae, a (basal) teleost group. Its scientific name is sometimes spelled S. jardini.