Description

Brachyplatystoma rousseauxii

Brachyplatystoma or Goliath catfishes is a genus of catfish from the family Pimolodidae that includes some of the largest species of catfish. Brachyplatystoma are found in the Amazon and Orinoco basins in South America, where they live in estuaria and deeper rivers. These fish are important foodfish.

Most species (but not all) of Brachyplatystoma migrate long distances upstream for reproduction. The habitat contains mostly white-water rivers, as black water does not contain enough food for migrating catfish.

Brachyplatystoma is described in 1862 and originates from Greek brachys, platys, and stoma, which mean short, flat, and mouth. Brachyplatystoma all exhibit long barbels extending past the dorsal fins and even extend to the caudal fin. The fins of young specimens are extended into long filaments. In most species these filaments are lost in adulthood. This genus is further characterized by its modified jaw muscles.

Brachyplatystoma rousseauxii 

Brachyplatystoma rousseauxii can reach 192 cm and can be distinguished by its platinum head and golden or silver colored body. It is the only species of Brachyplatystoma with short barbels when adult. Brachyplatystoma rousseauxii has a milk gland at the anterior upper part of its pectoral fins. Its function is unknown, but in Colombia this fish is known as lechero, which means milkman.

 After hatching upstream the Amazone river the small fish are taken downstream by the river to the riverdelta, which takes 13-20 days.  With the seasonal rise in waterlevel the Amazone delta is flooded with fresh water. Juvenile Brachyplatystoma enter the brakish estuary to prey on crustaceans and fish. When the seawater returns they retreat in to the river. Often the young specimens form schools.at that stadium of their lifecycle. After 3 years they start to migrate upstream in large numbers. During this upstream movement the fish are subject to intensive capture by commercial and artisanal fishing operations. Brachyplatystoma rousseauxii is the fourth most catched fish in the Amazone river system , thus an important foodfish. It is thought that the adult fish migrate to the exact placeof hatching to spawn. The total distance covered by some populations during migration from the delta was as much as 5500 km, making it the longest known in any freshwater fish species. All fish migrate upstream, since no adult speciments are found downstream the river.

Aquarium

According to its pelagic nature Brachyplatystoma rousseauxii is an active species. With a maximum size of 192 cm and their desire to migrate it hardly recommendable for keeping in an aquarium. Specimens that have been kept in an aquarium are peaceful to fish of a similar size. Because of their predatory nature (entirely piscivourous) they will swallow smaller fish.

The decoration of the aquarium is not that important. Requirements are dim lighting (it is deepwater species), sandy substrate, moderately current, a lot of swimming room and a high level of oxygen. Since the fish are adapted to live in low-sight conditions it is very sensitive to activity in the water so probably housing in a very crowded aquarium should be avoided. Since these fish need large amounts of food a large filtersystem and strict maintenance intervals are important. Temperature can be set between 22-28 degrees C, with a PH level between 6-8.

Feeding

Brachyplatystoma are entirely piscivourous. Most of the time they can be adapted to dead alternatives such as mussel, squid, strips of fish and prawn. Restrict feeding to 1 or 2 meals per week for an adult. Younger specimens somewhat more frequent.

Breeding

Given its complex natural lifecycle it is probably impossible to breed in captivity.

Video

https://www.youtube.com/watch?v=prOi3FbbZSY

Copyright photos

Enrico Richter (http://amazonpredators.wordpress.com)

References

• Breeding, growth and exploitation of Brachyplatystoma rousseauxii Castelnau, 1855 in the Caqueta River, Colombia (ISSN 1679-6225)
• Planetcatfish.com
• Serouslyfish.com
• Wikepedia