Common Name
	rendahl's tandan (rendahl's catfish)
Scientific Name
	Porochilus rendahli (Whitley, 1928)
Conservations Status
	Rare
Distribution and Abundance
	The species has only recently been recorded from the Basin. A number of individuals were captured from upstream reaches of Dogwood and Charlie's Creeks in the Condamine drainage of southern Qld during sampling for the Pilot Sustainable Rivers Audit. Subsequently, specimens have been collected from the Balonne catchment near St George. Outside the Basin it has a patchy distribution in northern Australia in the Kimberleys, Cape York , the Burdekin and coastal streams of the NT. Its northern Australian distribution indicates that is a warm water species and is unlikely to be widely distributed in the Basin.
Identification
	A small catfish with a relatively short first dorsal fin and the classic tandan feature of conjoined caudal and anal fins. Maximum size ~240 mm; usually less than 150 mm. The skin is smooth, with no scales. The body is slender with a roundly pointed tail. The head and nape profile is concave and the eyes are close to the snout. The longish nasal barbel extends to, or behind back of head, with other barbels reaching to or beyond the base of the pectoral fin. Colour ranges from light grey to almost black, sometimes mottled, or pale yellow-brown, generally with a golden sheen. A white form is also known. The individuals collected from the Basin differ slightly morphologically to other populations, and it is possible that genetic research may show that there are cryptic species within P. rendahli .
Biology and Habitat
	Virtually nothing is known of this tandan's ecology in the Basin, but elsewhere it is a benthic feeder, consuming relatively small items such as insect larvae, (predominantly chironomids and mayflies), microcrustaceans (ostracods or cladocerans) and detritus. In the Alligator Rivers region of the Northern Territory males mature at approximately 100 mm total length and females at 110 mm, and breeding occurs early in the wet season (~November-December). In this locality spawning occurs in muddy lowland lagoons. Average fecundity is about 900 eggs, but up to 3465 has been recorded. Mean egg diameter is 1.3 mm. Little is known of movement requirements other than that there is a migration into lowland lagoons to spawn, and an upstream movement to refuge habitats early in the dry season. In the Alligator Rivers region, Rendahl's tandan was recorded at surface water temperatures of from 26-38°C. It is found in both riverine and off-channel habitats, but is commonly recorded in lagoons. A benthic species, this tandan is found in greatest abundance in slow-flowing areas with dense submerged vegetation, indicating that it is tolerant of low dissolved oxygen levels.
Potential Threats
	Almost nothing is known of this species in the Basin, so it is difficult to identify threats. However wetland degradation and alienation may be issues to consider.
General References
	Click here for complete list of references
	Allen et al. 2002;
	Bishop et al . 2001;
	Larson & Martin 1989;
	MDBC 2004b;
	Pusey et al . 2004
PDF Links
	To download these PDFs visit our on-line publications ordering system through these links.
	Fish Factsheet - Rendahl's tandan
	Fishes of the Murray-Darling Basin: An introductory Guide