No country for native crayfish: importance of crustaceans in the diet of native and alien Northern raccoons

2021 ◽  
pp. 1-15
Author(s):  
Luca Boncompagni ◽  
Marco Molfini ◽  
Paola Ciampelli ◽  
Paola Fazzi ◽  
Marco Lucchesi ◽  
...  
Keyword(s):  
Native Crayfish

Effects of a native crayfish (Orconectes virilis) on the reproductive success and nesting behavior of sunfish (Lepomis spp.)

2004 ◽  
Vol 61 (11) ◽  
pp. 2135-2143 ◽  
Author(s):  
Nathan J Dorn ◽  
Gary G Mittelbach
Keyword(s):  
Reproductive Success ◽  
Lepomis Macrochirus ◽  
Lepomis Gibbosus ◽  
Orconectes Virilis ◽  
Negative Effects ◽  
Fish Prey ◽  
Natural Lakes ◽  
Successful Reproduction ◽  
Young Of The Year ◽  
Native Crayfish

While crayfish are traditionally considered fish prey, they are capable of feeding on substrate-bound fish eggs and their introductions have been blamed for the decline in fish populations in Europe and North America. To investigate their potential effects on fish reproductive success we measured the effects of a native crayfish (Orconectes virilis) on the reproductive success of two substrate-nesting sunfish, pumpkinseed (Lepomis gibbosus) and bluegill (Lepomis macrochirus), in replicated pond experiments. Crayfish were observed feeding on eggs in both experiments. Crayfish presence delayed successful reproduction by pumpkinseeds in densely vegetated ponds, resulting in lower young-of-the-year biomass in ponds with crayfish. In the second experiment, with bluegills in less-vegetated ponds, crayfish prevented successful reproduction entirely. However, when we added crayfish-proof exclosures to the crayfish ponds late in the summer, bluegills located the crayfish-free habitat and successfully reproduced inside the exclosures (1 month after first successful reproduction in control ponds). The results of these experiments demonstrate the potential strong negative effects of crayfish on sunfish reproduction and suggest that the spatial distribution of crayfish and other egg predators may influence fish nesting behaviors and habitat choices. Further studies are needed to determine the magnitude of crayfish effects in natural lakes and ponds where sunfish and crayfish co-occur.

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

2018 ◽  
pp. 15 ◽  
Author(s):  
Nicky Green ◽  
Matt Bentley ◽  
Paul Stebbing ◽  
Demetra Andreou ◽  
Robert Britton
Keyword(s):  
Ecological Impacts ◽  
Catch Per Unit Effort ◽  
Metal Base ◽  
Baited Traps ◽  
Trapping Method ◽  
Invasive Crayfish ◽  
Trapping Methods ◽  
Body Sizes ◽  
The Mean ◽  
Native Crayfish

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.

scholarly journals Effectiveness of stream sampling methods in capturing non-native Rusty Crayfish (Orconectes rusticus) in Ontario

2014 ◽  
Vol 128 (2) ◽  
pp. 111 ◽  
Author(s):  
Scott M. Reid ◽  
Jane Devlin
Keyword(s):  
Sampling Methods ◽  
Capture Probability ◽  
Sexually Active ◽  
Orconectes Rusticus ◽  
Rusty Crayfish ◽  
Stream Sampling ◽  
First Pass ◽  
Native Crayfish ◽  
Removal Model ◽  
Species Removal

Habitat alteration and species introductions have contributed to the decline of native crayfish in Ontario. although lake populations of crayfish in Ontario are monitored, there is no corresponding program for streams. We used removal-based sampling to evaluate the efficacy of three sampling techniques (backpack electrofishing, hand capture, and seining) to characterize native and non-native crayfish populations in six streams in the Kawartha lakes region and five streams in the Muskoka/Haliburton lakes region. all types were effective at detecting non-native Rusty Crayfish (Orconectes rusticus). Rusty Crayfish were collected from 65% of samples, constituted 90% of the total catch, and were the only species present in 30% of streams. Compared with other methods, electrofishing was more likely to capture additional crayfish species. Removal-based sampling was not a reliable approach for estimating capture probability and population size. Failure of the removal model was due to increases in the number of crayfish captured after the first pass or too few individuals collected. Mean capture probabilities for electrofishing (0.30) and hand capture (0.31) did not result in reliable population estimates. Compared with seining, electrofishing and hand capture resulted in more sexually active males (fewer sexually inactive males) and more small (< 25 mm carapace length) individuals. For each method, there were differences in capture probability among length classes. a combination of electrofishing and seining (with multiple passes) would maximize species detection, permit sampling of a range of habitat types, and be easily integrated into existing stream fish surveys.

scholarly journals Subterranean Invasion by Gapped Ringed Crayfish: Effectiveness of a Removal Effort and Barrier Installation

Diversity ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 3 ◽  
Author(s):  
Joshua Mouser ◽  
David Ashley ◽  
Tom Aley ◽  
Shannon Brewer
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Major Threat ◽  
Males And Females ◽  
Native Crayfish ◽  
Age Estimates

Non-native crayfish invasion is a major threat to many stream fauna; however, invasions in subterranean habitats are rarely documented. Our study objectives were to examine demographics and morphological and life-history traits of a gapped ringed crayfish Faxonius neglectus chaenodactylus population that invaded Tumbling Creek Cave and determine the effects of removal on the population. Crayfish were found throughout the cave though fewer individuals were observed upstream of an installed weir. Fecund females were collected in nearly all months, but were prevalent during spring (February–June). Males and females were of similar sizes. Males had larger chelae and chelae that were regenerated slightly more often than females. Removal of >4000 crayfish since 2011 resulted in reduced abundances, but the population persisted. Age estimates from counting bands on gastric mills indicated crayfish within the cave lived longer than populations in nearby Big Creek (6 vs. 4 years). Recent efforts to prevent upstream cave migrations included a barrier installation and since installation, few crayfish have been located upstream. We show that exploitation of new environments may lead to trait changes (i.e., reproduction and longevity). We also demonstrate that barriers reduce the spread of invasion at a comparable cost to removal. We hypothesize that increased reservoir elevation inundates springs hydrologically connected to the cave and this may be the invasion source.

Vulnerability of Southwest Iberian amphibians to an introduced crayfish, Procambarus clarkii

2005 ◽  
Vol 26 (3) ◽  
pp. 293-303 ◽  
Author(s):  
Rui Rebelo ◽  
Maria João Cruz
Keyword(s):  
Procambarus Clarkii ◽  
Larval Survival ◽  
Bufo Bufo ◽  
Microhabitat Use ◽  
Amphibian Species ◽  
Embryo Survival ◽  
Breeding Habitats ◽  
Mesocosm Experiments ◽  
Native Crayfish ◽  
Crayfish Species

AbstractThe introduction of predators in amphibian breeding habitats may contribute to the decline or extinction of amphibian populations. Procambarus clarkii, a North American crayfish, was recently introduced in the Iberian Peninsula, being now quite abundant in the southwest, a region with no native crayfish species and where 13 amphibian species may be found. We performed mesocosm experiments to evaluate the vulnerability of amphibian embryos and larvae from those species to P. clarkii. Despite the presence of alternative food (vegetation and leaf litter), embryo survival in the presence of P. clarkii was low for all species except Bufo bufo. However, newly hatched B. bufo tadpoles were readily consumed. P. clarkii reduced larval survival in all species, with those species that in nature have few contacts with predators at the larval stage suffering the highest mortalities. Most larvae reduced their activity and/or altered microhabitat use in the presence of P. clarkii, but these behavioural modifications did not lead necessarily to a low vulnerability to predation.

Age, growth, and condition of the Mud River crayfish Orconectes ronaldi Taylor 2000 (Decapoda: Cambaridae)

2015 ◽  
Vol 21 (1) ◽  
pp. 115-121
Author(s):  
Hannah Noss ◽  
Wendy Anderson ◽  
Thomas P. Simon
Keyword(s):  
Statistical Difference ◽  
Sexually Dimorphic ◽  
Allometric Growth ◽  
Native Range ◽  
South Central ◽  
Length Width ◽  
Wet Weight ◽  
Native Crayfish ◽  
Sexually Mature ◽  
Crayfish Species

Abstract The Mud River crayfish, Orconectes ronaldi Taylor, is a native crayfish species found in the Midwestern United States in Kentucky and Indiana. Length-weight relationship, body morphometric relationship, and condition within the species native range in south-central Indiana were studied. Growth, size relationships based on gender, sexual phase for adults and juveniles and chelae-length/width relationships were used to interpret patterns in sexual dimorphism. Carapace length (CL)–wet weight (Wwt) relationships for all genders (i.e., male, female, juvenile) and all male forms (form I and II) had positive allometric growth. Male individuals were not significantly heavier than females of the same length. The maximum length and weights of males (35.1 mm CL) were longer and heavier (11.8 g) than the longest female (31.5 mm) weighing 8.3 g. No statistical difference in mean weight was observed; however, this is attributed to the accelerated development of the chelae in sexually mature form I males, whereas chelae of females grow slower throughout life. Chelae length was significantly different between male form II and male form I, and male form II and females (P = 0.004, and P <0.001, respectively). The relatively longer chelae of form I and form II males are due to sexually dimorphic change.

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