Species-specific differences in dynamics of agonistic interactions may contribute to the competitive advantage of the invasive signal crayfish (<i>Pacifastacus leniusculus</i>) over the native narrow-clawed crayfish (<i>Astacus leptodactylus</i>)

Non-native crayfish can dominate the invertebrate biomass of invaded freshwaters, with their high ecological impacts resulting in their populations being controlled by numerous methods, especially trapping. Although baited funnel traps (BTs) are commonly used, they tend to be selective in mainly catching large-bodied males. Here, the efficacy and selectivity of BTs were tested against an alternative trapping method based on artificial refuges (ARTs) that comprised of a metal base with several tubes (refuges) attached. The target species was signal crayfish Pacifastacus leniusculus in an upland river in southwest England. Trapping was completed in April to October over two consecutive years. In total, 5897 crayfish were captured, with 87% captured in ARTs. Comparison of the catch per unit effort (CPUE) between the trapping methods in the same 24 hour periods revealed significantly higher CPUE in ARTs than of BTs. ARTs fished for 6 consecutive days had higher catches than both methods over 24 hours. Whilst catches in BTs were significantly dominated by males (1.49M:1F), the sex ratio of catches in ARTs was 0.99M:1F. The mean carapace length of crayfish was also significantly larger in BTs (43.2 ± 0.6 mm) than in ARTs (33.6 ± 0.2 mm). Thus, ARTs had higher CPUE over 24 hour and 6 day periods versus BTs and also captured a greater proportion of smaller and female individuals. These results indicate that when trapping methods are deployed for managing invasions, the use of ARTs removes substantial numbers of crayfish of both sexes and of varying body sizes.

Section: Discussionmentioning

confidence: 99%

Trapping for invasive crayfish: comparisons of efficacy and selectivity of baited traps versus novel artificial refuge traps

Green

Bentley

Stebbing

et al. 2018

“…Since A. leptodactylus is known to be moderately resistant to the pathogen A. astaci (Kokko et al, 2012;Svoboda et al, 2012), we may expect its further slow-paced disappearance in contact zones with NICS, mainly due to competitive exclusions (Hudina et al, 2016), and further spreading and replacement of other ICS in continental Croatia.…”

Section: Discussionmentioning

confidence: 99%

“…As for A. leptodactylus, the most robust European native species that shows some invasive characteristics (Holdich et al, 2009;Hudina et al, 2016;Perdikaris et al, 2017b), collected data indicated their spreading into new areas previously inhabited by A. astacus , and at the same time their disappearance due to NICS dispersal (this study, Hudina et al, 2013Hudina et al, , 2017Rebrina et al, 2015). Since A. leptodactylus is known to be moderately resistant to the pathogen A. astaci (Kokko et al, 2012;Svoboda et al, 2012), we may expect its further slow-paced disappearance in contact zones with NICS, mainly due to competitive exclusions (Hudina et al, 2016), and further spreading and replacement of other ICS in continental Croatia.…”

Section: Discussionmentioning

confidence: 99%

“…The NICS biological and ecological characteristics of adaptability, aggressiveness, high fecundity, etc. have severe, adverse impacts on ICS (Westman et al, 2002, Twardochleb et al, 2013 resulting them being ousted from their habitats (Füreder et al, 2006;Hudina et al, 2016). Furthermore, some NICS are latent carriers of the pathogen A. astaci, causative agent of crayfish plague, which is lethal for ICS (Edgerton et al, 2004;Souty-Grosset et al, 2006;Filipová et al, 2013;Rezinciuc et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Recent changes in distribution pattern of freshwater crayfish in Croatia − threats and perspectives

Maguire

Klobučar

Žganec

et al. 2018

Self Cite

-Analysis of Croatian freshwater crayfish populations, aiming to gather new distributional data and complement previous surveys (2005)(2006)(2007)(2008)(2009)(2010)(2011), was performed during 2014-2016, within the frame of Natura 2000 Integration Project. The research included different waterbodies across the whole of Croatia, harbouring both indigenous and non-indigenous crayfish species (ICS and NICS, respectively). Field work was conducted in 117 grid squares with dimensions 10 Â 10 km, and up to four waterbodies were surveyed per grid square, making a total of 450 studied sites. Out of those, crayfish were not recorded in 368 sites. In the sites with crayfish presence (i.e., 82), the most frequently observed ICS was Astacus astacus (registered in 33 sites) followed by Austropotamobius pallipes (16 sites), Austropotamobius torrentium (12 sites), and Astacus leptodactylus (5 sites). Concerning NICS, the majority of records were for Orconectes limosus (13 sites), followed by Pacifastacus leniusculus (2 sites), whereas Procambarus fallax f. virginalis was registered in only one locality. Comparisons of obtained data with those from previous surveys showed that NICS are progressively spreading and displacing ICS, as recorded for A. leptodactylus that was almost completely displaced by O. limosus in waterbodies of the east Croatia. Existing ICS populations are under growing anthropogenic preassure, frequently fragmented and isolated. Moreover, this survey showed that in the last decade 55% of A. astacus and 67% of A. pallipes populations disappeared mainly as a consequence of anthropogenic influence onto their habitats. Further monitoring and conservation actions for ICS should be urgently applied to mitigate negative impacts of both NICS and anthropogenic influence. (ICS et NICS, respectivement). Le travail sur le terrain a été effectué dans un quadrillage de 117 quadrats de dimensions 10 Â 10 km, et jusqu' à quatre plans d'eau ont été étudiés par quadrat, ce qui fait un total de 450 sites étudiés. Parmi ceux-ci, les écrevisses n'ont pas été recensées dans 368 sites. Dans les sites où il y avait des écrevisses (c. -à-d. 82), l'ICS le plus fréquemment observé était Astacus astacus (enregistré dans 33 sites), suivi de Austropotamobius pallipes (16 sites), Austropotamobius torrentium (12 sites) et Astacus leptodactylus (5 sites). En ce qui concerne le NICS, la majorité des signalements concernaient Orconectes limosus (13 sites), suivi de Pacifastacus leniusculus (2 sites), tandis que Procambarus fallax f. virginalis n' a été enregistrée que dans une seule localité. Les comparaisons des données obtenues avec celles des enquêtes précédentes ont montré que les NICS se répandent et déplacent progressivement les ICS, comme cela a été enregistré pour A. leptodactylus qui a été presque complètement déplacé par O. limosus dans les masses d'eau de l'est de la Croatie. Les populations actuelles d'ICS sont de plus en plus souvent exposées à une pression anthropique croissante, fragmentées et isolées. En outre, cett...

“…Compared to other native European species, the narrowclawed crayfish grows larger and is more tolerant to altered ambient conditions (Stucki, 1999;Souty-Grosset et al, 2006). It spreads and colonises new habitats, frequently displacing other native species (Bij de Vaate et al, 2002;Maguire et al, 2011b;Hudina et al, 2016). Also, since it is commercially important, it has been frequently relocated (Bij de Vaate et al, 2002;Harlio glu, 2004;Kouba et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Narrow-clawed crayfish in Finland: Aphanomyces astaci resistance and genetic relationship to other selected European and Asian populations

Jussila

Maguire

Kokko

et al. 2020

Self Cite

The narrow-clawed crayfish (Pontastacus leptodactylus) is an alien species in Finland with only a few populations reported from the southeastern region during the last century. We discovered a productive population in the lake Jängynjärvi, which is upstream from the previously reported wild narrow-clawed crayfish population in that region. Preliminary studies indicated that this population is not infected with Aphanomyces astaci. We collected narrow-clawed crayfish samples from the lake Jängynjärvi population for both infection challenge and genetic studies, in order to investigate possible A. astaci resistance among this Finnish population and to evaluate their phylogenetic position that would enable us to speculate different scenarios of distribution pathways or origin of the population. The infection studies indicated that the narrow-clawed crayfish in this population were more resistant against A. astaci infection (B haplogroup A. astaci) compared to the noble crayfish (Astacus astacus) from the lake Rytky in North Savo, while all crayfish of both species in the B haplogroup A. astaci challenged groups died within 58 days post-infection. Results of the phylogenetic reconstruction indicate that the lake Jängynjärvi narrow-clawed crayfish are closely related to narrow-clawed crayfish from the lake Bolshoye near Krasnoye, located on the White Sea island of Solovestky and also populations from Tyumen region, both in Russia. This could confirm previous speculations about introduction of the narrow-clawed crayfish from Russia into Finland or could indicate previous hydrological connection.