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Abstract(s)
A tecnologia designada por PIT-Telemetria (Passive Integrated Transponder
PIT-Telemetry Technology) foi usada para avaliar o comportamento duma
comunidade de peixes no verão de 2011, no rio Sabor, no Nordeste de
Portugal. O estudo foi realizado num troço de aptidão mista, i.e. salmonícola/
ciprinícola que englobou uma sequência riffle/pool representativa do
ecossistema lótico. Foram cirurgicamente implantados 30 PIT-tags (12,0 mm
comprimento x 2,1 mm diâmetro) distribuídos por 6 exemplares de cada uma
das 5 espécies autóctones usadas no estudo. Os dados biométricos foram os
seguintes: 1) Salmo trutta (Comprimento total: 17,8 ± 2,6 cm; biomassa: 73,6 ±
24,2 g); 2) Pseudochondrostoma duriense (14,2 ± 1,5 cm; 21,6 ± 4,3 g); 3)
Squalius carolitertii (10,2 ± 0,9 cm; 13,2 ± 2,4 g); 4) Luciobarbus bocagei (14,0
± 1,4 cm; 33,1 ± 2,4 g); e 5) Squalius alburnoides (7,0 ± 3,2 cm; 6,6 ± 1,7 g).
Foi estabelecida uma condição simpátrica numa área confinada e
monitorizado o comportamento dos peixes a partir duma unidade MPD (multipoint
decoder) conectada a oito antenas independentes, colocadas em
diferentes microhabitats. Estas antenas foram reposicionadas aleatoriamente
com uma periodicidade de três dias durante o período de estudo (sete
semanas de monitorização). Os resultados confirmaram que a PIT-telemetria
foi um método eficiente para avaliar o comportamento, em termos movimento e
uso do microhabitat, das populações simpátricas de ciprinídeos e salmonídeos.
Detetaram-se, pelo menos uma vez, todos os peixes marcados com PIT-tags.
As técnicas multivariadas aplicadas (NMDS, dbRDA) mostraram uma
separação no uso do habitat entre a população de trutas e as restantes
populações de ciprinídeos. As trutas usaram, prioritariamente, os
mais próximos das zonas de corrente (riffles) e com cobertura (blocos, raízes e
ensombramento). Pelo contrário, os ciprinídeos demonstraram maior
mobilidade e um padrão de atividade diferente das trutas. Finalmente entre os
ciprinídeos, os escalos localizaram-se preferencialmente junto às margens
enquanto as bogas e os barbos foram encontrados maioritariamente no centro
do canal, sem uma preferência declarada por áreas de refúgio.
The PIT-Telemetry technology (Passive Integrated Transponder) was used to evaluate the behavior of a fish community in the summer of 2011, in the River Sabor, located in Northeastern Portugal. The study was conducted on a salmonid / cyprinid reach, which included a riflle/pool sequence, representative of lotic ecosystems of the region. 30 PIT-tags (12.0 mm long x 2.1 mm diameter) were surgically implanted in six fish of each five native species used in the study. Biometric data were the following: 1) Salmo trutta (Total Lenght: 17.8 ± 2.6 cm; biomass: 73.6 ± 24.2 g); 2) Pseudochondrostoma duriense (14.2 ± 1.5 cm; 21.6 ± 4.3 g); 3) Squalius carolitertii (10.2 ± 0.9 cm; 13.2 ± 2.4 g); 4) Luciobarbus bocagei (14.0 ± 1.4 cm; 33.1 ± 2.4 g); e 5) Squalius alburnoides (7.0 ± 3.2 cm; 6.6 ± 1.7 g). A sympatric condition was established in the blocked area and the behavior of the fish monitored from a MPD (multi-point decoder) unit connected to eight independent antennas, placed in different microhabitats. These antennas were repositioned randomly at intervals of three days during the study period (seven weeks of monitoring). The results confirmed that the PIT telemetry is an efficient method to evaluate the performance, in terms of movement and microhabitat use, of the sympatric fish populations considered. All tagged fishes were registered, at least one time, during the experiment. The applied multivariate techniques (NMDS, dbRDA) showed a separation in microhabitat use between trout population and the remaining cyprinid populations. Trout individuals used primarily microhabitats areas nearby current (riffles) and cover (blocks, roots and shadind zones) conditions. Cyprinids showed a greater mobility and a different activity pattern comparing with trout behavior. Finally among cyprinids, Iberian northern chub were located preferentially along the banks while Iberian nase and barbel were found, mostly, in the centre of the channel, without any preference for refuge areas.
The PIT-Telemetry technology (Passive Integrated Transponder) was used to evaluate the behavior of a fish community in the summer of 2011, in the River Sabor, located in Northeastern Portugal. The study was conducted on a salmonid / cyprinid reach, which included a riflle/pool sequence, representative of lotic ecosystems of the region. 30 PIT-tags (12.0 mm long x 2.1 mm diameter) were surgically implanted in six fish of each five native species used in the study. Biometric data were the following: 1) Salmo trutta (Total Lenght: 17.8 ± 2.6 cm; biomass: 73.6 ± 24.2 g); 2) Pseudochondrostoma duriense (14.2 ± 1.5 cm; 21.6 ± 4.3 g); 3) Squalius carolitertii (10.2 ± 0.9 cm; 13.2 ± 2.4 g); 4) Luciobarbus bocagei (14.0 ± 1.4 cm; 33.1 ± 2.4 g); e 5) Squalius alburnoides (7.0 ± 3.2 cm; 6.6 ± 1.7 g). A sympatric condition was established in the blocked area and the behavior of the fish monitored from a MPD (multi-point decoder) unit connected to eight independent antennas, placed in different microhabitats. These antennas were repositioned randomly at intervals of three days during the study period (seven weeks of monitoring). The results confirmed that the PIT telemetry is an efficient method to evaluate the performance, in terms of movement and microhabitat use, of the sympatric fish populations considered. All tagged fishes were registered, at least one time, during the experiment. The applied multivariate techniques (NMDS, dbRDA) showed a separation in microhabitat use between trout population and the remaining cyprinid populations. Trout individuals used primarily microhabitats areas nearby current (riffles) and cover (blocks, roots and shadind zones) conditions. Cyprinids showed a greater mobility and a different activity pattern comparing with trout behavior. Finally among cyprinids, Iberian northern chub were located preferentially along the banks while Iberian nase and barbel were found, mostly, in the centre of the channel, without any preference for refuge areas.
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Keywords
Peixes Comportamento Microhabitat Monitorização PIT- telemetria