''Leiarius'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

long-whiskered catfish The Pimelodidae, commonly known as the long-whiskered catfishes, are a family of catfishes (order Siluriformes). Taxonomy The family Pimelodidae has undergone much revision. Currently, it contains about 30 genera and about 90 recognized and know ...

es native to

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

. Most of the genus' species are found in the

aquarium An aquarium (: aquariums or aquaria) is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. fishkeeping, Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquati ...

hobby A hobby is considered to be a regular activity that is done for enjoyment, typically during one's leisure time. Hobbies include collecting themed items and objects, engaging in creative and artistic pursuits, playing sports, or pursuing other ...

as ornamental fish.

Species

There are currently four recognized species in this genus: * '' Leiarius arekaima'' (

Jardine Jardine is a surname. Notable people with the surname include: * Al Jardine (born 1942), member of the Beach Boys * Alexander Jardine (British Army officer) (died 1799), Scottish army officer and author * Alexander Jardine (Medal of Honor) (1874– ...

, 1841) * '' Leiarius longibarbis'' ( Castelnau, 1855) * '' Leiarius marmoratus'' ( T. N. Gill, 1870) (Marbled catfish, Marbled pim) * '' Leiarius pictus'' (

Müller Müller may refer to: Companies * Müller (company), a German multinational dairy company ** Müller Milk & Ingredients, a UK subsidiary of the German company * Müller (store), a German retail chain * GMD Müller, a Swiss aerial lift manufacturi ...

& Troschel, 1849) (Marbled sailfin catfish, Sailfin pim)

Anatomy and physiology

''L. marmoratus'' can reach a little more than 100

centimetre upright=1.35, Different lengths as in respect to the electromagnetic spectrum, measured by the metre and its derived scales. The microwave is in-between 1 meter to 1 millimeter. A centimetre (International spelling) or centimeter (American ...

s (39 in) TL and has a maximum published weight of about 12

kilogram The kilogram (also spelled kilogramme) is the base unit of mass in the International System of Units (SI), equal to one thousand grams. It has the unit symbol kg. The word "kilogram" is formed from the combination of the metric prefix kilo- (m ...

s (26 lb). ''L. pictus'' grows to 60 cm (24 in) TL. These two species can be easily confused. The body of ''L. pictus'' is brown with darker brown spots, with a paler ventral coloring. In juvenile ''L. pictus'', two parallel, pale bands curve from the

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

down the body towards the

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

. In young fish of both species, the maxillary barbels are very long and ringed with black and white. As both of these species grow, their barbels will shorten in proportion to their size, and the caudal fin lobes, which are rounded in the young, become much more pointed. As ''L. marmoratus'' grows older, it darkens and its dark spots develop into a marbled pattern. Both species have a large, sail-like dorsal fin. There are no external sexual differences.

Range and distribution

''L. marmoratus'' is found in the

Amazon Amazon most often refers to: * Amazon River, in South America * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon (company), an American multinational technology company * Amazons, a tribe of female warriors in Greek myth ...

, Essequibo, and

Orinoco River The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers approximately 1 million km2, with 65% of it in Venezuela and 35% in Colombia. It is the List of rivers by discharge, f ...

basins. On the other hand, ''L. pictus'' is only found in the Amazon and Orinoco River basins.

Ecology

''L. marmoratus'' inhabits riverbeds, deep wells, and lakes. Young or sub-adults form large schools. This species prefers to lay over rock and tree trunks during the day, being more active at sunrise, sunset, and night.

Importance to humans

In aquaria

Both ''L. marmoratus'' and ''L. pictus'' are ornamental fish kept as pets in the

. They have a voracious appetite and can grow rapidly, and therefore should be kept in a very large aquarium. These fish are peaceful towards other large fish. Some sort of retreat to allow these fish to hide during the day is required. These fish get very large and are not recommended for the average aquarist.

References

Bibliography

* {{Taxonbar, from=Q6519053 Pimelodidae Fish of South America Fish of the Amazon basin Catfish genera Taxa named by Pieter Bleeker Freshwater fish genera