Activity patterns of South American silver catfish (Rhamdia quelen)

Abstract

The South American silver catfish (Rhamdia quelen) is a widely distributed species in Central and South America in areas east of the Andes between Venezuela and the northern parts of Argentina. The bottom dwelling species occurs in lakes and reservoirs as well as in rivers. Between June 2000 and December 2001, sixteen silver catfish were tracked during fourteen 24-h cycles in two-hour-intervals, with the aim of investigating daily movements and habitat use. Covered distances varied between 0 m/2 h and 326 m/2 h and the mean distance covered in 2 h was 25.6 m. The mean activity of individual silver catfish varied between 5.6 m/2 h and 81.4 m/2 h. The swimming activity was linearly related to the total fish length. The highest mean swimming activity occurred in the morning and at nightfall. Silver catfish concentrated in three areas of frequent use. All of them were characterized by steep banks providing shelter in the form of rip-rap or large woody debris. Vertically, silver catfish preferred the upper 2 m layer where tracked fish encountered higher temperatures and higher dissolved oxygen concentrations.

Diel and seasonal movements of grumatã Prochilodus lineatus (Valenciennes 1836) (Characiformes: Prochilodontidae) in the Sinos River, Southern Brazil

“…In previous tests using the tagging method, incisions closed within two weeks and no negative effects were detected for silver catfish (Rhamdia quelen Quoy and Gaimard, 1824) growth (Schulz, 2003) and movements (Schulz and Leuchtenberger, 2006).…”

Effects of stocking density on dispersal behavior of Brazilian freshwater dourado (Salminus brasiliensis) in a subtropical river headwater

“…Since the carrying capacity of the Sinos River was unknown, stocking density was based on recommendations for salmon smolts which are stocked at approximately the same body size (Aprahamian et al, 2003). A subsample of 13 individuals was tagged with digitally coded radio transmitters (Lotek NanoTags NTC-4-2L, 87 days battery life, 2.6 g weight in air; transmitter-bodyweight relation < 3%) using the standard surgical procedure described by Schulz & Leuchtenberger (2006).…”

Characterization of an IgM-like immunoglobulin from silver catfish (Rhamdia quelen) serum and its use for the production of polyclonal antibodies and development of immunoassays

“…Silver catfish (Rhamdia quelen) is an indigenous species endemic to South American rivers and lakes and considered a good candidate for intensive husbandry in neotropical and temperate climates (Schulz & Leuchtenberger 2006) either alone or commingled with other fish species (Da Silva et al 2008). However, the continuous growth of fish husbandry and intensive production systems comes along with new challenges like outbreaks of infectious diseases and the need to monitor exposure to microorganism (Secombes 2008).…”