Migratory Movements of Large Catfish in the Xingu River (Amazon

Migratory Movements of Large Catfish in the Xingu River (Amazon)
Revealed By Combined Acoustic and Radio Telemetry
Thursday, August 21, 2014: 2:30 PM
302B (Centre des congrès de Québec // Québec City Convention Centre)
Lisiane Hahn , Neotropical Environmental Consulting, Passo Fundo, Brazil
Eduardo G. Martins , Department of Forest and Conservation Sciences, University of British
Columbia, Vancouver, BC, Canada
Domingos Garrone Neto , UNESP, Registro, Brazil
Luís da Câmara , Neotropical Environmental Consulting, Passo Fundo, Brazil
The Amazon basin is home to a large number of migratory fishes whose behavior is still poorly
known. Historical fisheries catch data suggest that critical habitats of large migratory catfish are
often separated by hundreds of kilometers. We used acoustic (fixed) and radio (fixed and mobile)
telemetry to investigate migratory movements of redtail (Phractocephalus hemioliopterus) and
surubim (Pseudoplatystoma spp.) catfish along a 700-rkm stretch of the Xingu River. Fish were
tagged and released downstream (62 redtail and 36 surubim) and upstream (47 redtail and 13
surubim) of a long stretch of rapids (known as the “Big Bend”) located in the lower river that is
considered a natural barrier to upstream fish migrations. Only tagged surubim (n=4) moved
upstream of the rapids, whereas movements downstream of the rapids were not detected for
either species. Thirteen redtail and five surubim catfish moved >50rkm upstream (56—329rkm)
of the release sites at the end or beginning of the floods. These findings suggest the Xingu River
rapids are not a barrier to the upstream migration of surubim and that both species migrate
upstream to distant habitats during the floods (presumably for spawning).