Ficha de avaliação EICAT
Pacifastacus leniusculus Dana, 1852
MR · Alto
Avaliação histórica recuperada de registros do SIGEEI. A estrutura e os campos foram preservados; a confirmação permanece pendente.
Identificação e síntese
Nomenclature and linkage
The original assessment name is preserved. The accepted name and synonyms support discovery and reconciliation without overwriting the historical EICAT record.
Taxonomia registrada
Classificação canônica recuperada da integração com o GBIF. O sistema explicita os níveis que a própria resposta do GBIF não informa.
Avaliação de impactos
1. Redução no desempenho de indivíduos da biota nativa
Resposta: Sim
Mecanismos selecionados: (1) Competição,(2) Predação,(4) Transmissão de doenças para espécies nativas
2. Declínio no tamanho populacional de espécie nativa
Resposta: Sim
Mecanismos selecionados: (1) Competição,(4) Transmissão de doenças para espécies nativas
Evidências por mecanismo
it was shown that signal crayfish influenced Atlantic salmon sheltering behaviour more than conspecific competitors. The number of Atlantic salmon sheltering was reduced by 50% (halved) when Atlantic salmon competitors were replaced by signal crayfish. Atlantic salmon were less able to defend a shelter against a signal crayfish competitor than against another fish. Moreover, in trials in which Atlantic salmon and signal crayfish competed directly for shelter, signal crayfish were the sole occupiers of shelters seven-times as often as Atlantic salmon (64% compared to 9% of occasions). The results suggest that under the conditions imposed in this study, signal crayfish outcompete Atlantic salmon for shelters when refuge is limiting. The study also suggests that intimidation, rather than overt aggression, may be the mechanism of exclusion (Griffiths & Armstrong, 2002b)....... Sheltering is thought to be an antipredator strategy (Valdimarsson & Metcalfe, 1998) and Atlantic salmon excluded from shelters may incur an increased risk of predation while in the water column. Fish excluded from shelters may also have to expend more energy if forced to swim in the water current rather than sheltering in positions of low water flow (Valdimarsson & Metcalfe, 1998). Atlantic salmon will not readily share shelters as the availability of refuges decreases relative to fish density (Armstrong & Griffiths, 2001). The introduction of signal crayfish into rivers may therefore result in a decline in Atlantic salmon stocks. (Griffiths et al., 2004)
The spread of P. leniusculus throughout Europe has enabled Aphanomyces astaci, the crayfish plague, to spread as well, decimating native crayfish populations (Holdich et al., 2009).
Referências: Griffiths, S. W., Collen, P., & Armstrong, J. D. (2004). Competition for shelter among over-wintering signal crayfish and juvenile Atlantic salmon. Journal of Fish Biology, 65(2), 436–447. doi:10.1111/j.0022-1112.2004.00460.x; Guan, R.-Z., & Wiles, P. R. (1997). Ecological Impact of Introduced Crayfish on Benthic Fishes in a British Lowland River. Impacto Ecologico de un Langostino de Rio Introducido en Poblaciones de Peces Bentonicos de un Rio de las Tierras Bajas Britanicas. Conservation Biology, 11(3), 641–647. doi:10.1046/j.1523-1739.1997.96073.x; Holdich, D. M., Reynolds, J. D., Souty-Grosset, C., Sibley, P. J., 2009. A review of the ever increasing threat to European crayfish from non-indigenous crayfish species. Knowledge and Management of Aquatic Ecosystems, (No.394/395), 11. http://www.kmae-journal.org/articles/kmae/pdf/2009/03/kmae09055.pdf doi: 10.1051/kmae/2009025;
3. Extinção local de população nativa
Resposta: Sim
Mecanismos selecionados: (1) Competição,(4) Transmissão de doenças para espécies nativas
Evidências por mecanismo
Sooty crayfish (see Pacifastacus nigrescens in IUCN Red List of Threatened Species), a native to the western USA, has become extinct partly due to interspecific competition with P. leniusculus, which was introduced into its range. P. leniusculus has also been implicated in causing a reduction in the range of the already narrowly endemic shasta crayfish ( see Pacifastacus fortis in IUCN Red List of Threatened Species) in the western America (Taylor, 2002).
The spread of P. leniusculus throughout Europe has enabled Aphanomyces astaci, the crayfish plague, to spread as well, decimating native crayfish populations (Holdich et al., 2009).
Referências: Holdich, D. M., Reynolds, J. D., Souty-Grosset, C., Sibley, P. J., 2009. A review of the ever increasing threat to European crayfish from non-indigenous crayfish species. Knowledge and Management of Aquatic Ecosystems, (No.394/395), 11. http://www.kmae-journal.org/articles/kmae/pdf/2009/03/kmae09055.pdf doi: 10.1051/kmae/2009025; Griffiths, S. W., Collen, P., & Armstrong, J. D. (2004). Competition for shelter among over-wintering signal crayfish and juvenile Atlantic salmon. Journal of Fish Biology, 65(2), 436–447. doi:10.1111/j.0022-1112.2004.00460.x; Guan, R.-Z., & Wiles, P. R. (1997). Ecological Impact of Introduced Crayfish on Benthic Fishes in a British Lowland River. Impacto Ecologico de un Langostino de Rio Introducido en Poblaciones de Peces Bentonicos de un Rio de las Tierras Bajas Britanicas. Conservation Biology, 11(3), 641–647. doi:10.1046/j.1523-1739.1997.96073.x
4. Reversibilidade da extinção local após remoção do táxon
Resposta: Reversível
Mecanismos selecionados: (1) Competição,(4) Transmissão de doenças para espécies nativas