Silver arowana

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Silver arowana
Systematics
Subclass : Real bony fish (Teleostei)
Overcohort : Osteoglossomorpha (Osteoglossomorpha)
Order : Bony tongues (Osteoglossiformes)
Family : Bonytongues (Osteoglossidae)
Genre : Scleropages
Type : Silver arowana
Scientific name
Scleropages macrocephalus
Pouyaud , Sudarto & Teugels , 2003

The silver arowana ( Scleropages macrocephalus ) is a predatory fish from the family of osteoglossids (Osteoglossidae). The species was named after its relatively large head ( size : "macros" = large, wide, long; "kephalé" = head).

description

The Silver Arowana has an elongated and slender body, laterally flattened. The paratypes examined at the first description were 29.3 to 43.1 cm long. The body height is about a quarter of the standard length . The head is large and taller than it is long. The width is more than three quarters of the head length. The mouth is oblique, the maxillary long and extends below the rear edge of the eye. There are two short, thick barbels at the tip of the lower jaw . The pectoral fins are long (more than 3/4 the standard length) and usually do not reach the base of the pelvic fins, which are only half the length of the pectoral fins. The anal fin is short (less than 28% of the standard length).

The Silver Arowana has a dark gray back and silver body sides. Most of the large scales have a circular, dark gray or olive colored ring. The ventral side is whitish or silvery. The unpaired fins of the West Kalimantan population are dark gray. In the population from Central Kalimantan the fin membrane is yellowish, the fin rays are dark gray.

distribution

The Silver Arowana occurs in Central and West Kalimantan ( Kapuas ) in small rainforest streams and larger white water and clear water rivers with more or less strong flowing water. The pH value of the home waters is above 6. The populations from Central and West Kalimantan are separated by the Schwaner Range .

Reproduction

Like all bone-wingers, the Silver Arowana is a mouthbrooder . The eggs are large and reach a diameter of 1.38 to 1.58 cm. The fry are 6 to 7 cm long at birth. The number of eggs in a clutch is less than 50.

Systematics

The Silver Arowana was originally considered color morph of the Asian Fork Barts ( Scleropages formosus ) until 2003 as a separate species described was. It appears sympatric with the Asiatic fork beard without mixing with it.

literature

  • Pouyaud, Laurent; Sudarto & Guy Teugels (December 2003): The Different Color Varieties of the Asian Arowana Scleropages formosus (Osteoglossidae) are distinct species: Morphologic and genetic evidences. Cybium 27 (4): 287-305. PDF

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