Find research datasets worth reusing

FIGURE 24. Partial cladogram from Taylor & Knouft 2006 showing Clade B in Review of crayfish color patterns in the Family Cambaridae (Astacoidea), with discussion of their possible importance

FIGURE 24. Partial cladogram from Taylor & Knouft 2006 showing Clade B, and indicating that Faxonius wrighti, Faxonius erichsonianus, and Faxonius spinosus are closely related species, but were originally put into separate subgenera.

FIGURE 27 in Review of crayfish color patterns in the Family Cambaridae (Astacoidea), with discussion of their possible importance

FIGURE 27. Comparison of color patterns of Procambarus suttkusi and Procambarus spiculifer from Subclade A with the color patterns of Procambarus vioscai paynei and Procambarus versutus from Subclade B.

FIGURE 20 in Review of crayfish color patterns in the Family Cambaridae (Astacoidea), with discussion of their possible importance

FIGURE 20. Modified distribution map showing the distribution of Faxonius putnami and Faxonius spinosus before evaluation of color patterns (modified from Taylor 2000).

FIGURE 21 in Review of crayfish color patterns in the Family Cambaridae (Astacoidea), with discussion of their possible importance

FIGURE 21. Comparison of color patterns and mesial view of gonopods of Faxonius putnami from the Cumberland and Green rivers in Kentucky and Tennessee and formerly Faxonius putnami from the Tennessee River in northern Alabama.

FIGURE 23 in Review of crayfish color patterns in the Family Cambaridae (Astacoidea), with discussion of their possible importance

FIGURE 23. Modified distribution map showing the distribution of Faxonius putnami, Faxonius yanahlindus, and Faxonius spinosus after evaluation of color patterns (modified from Taylor 2000).

FIGURE 19 in Review of crayfish color patterns in the Family Cambaridae (Astacoidea), with discussion of their possible importance

FIGURE 19. Comparison of color patterns and mesial view of gonopods of Faxonius perfectus and Faxonius palmeri palmeri.

FIGURE 14 in Review of crayfish color patterns in the Family Cambaridae (Astacoidea), with discussion of their possible importance

FIGURE 14. Camouflage color patterns found in Cambarus cracens, Faxonius jonesi, Faxonius lancifer, Cambarus rusticiformis, Cambarellus shufeldtii, and Hobbseus prominens.

FIGURE 2 in Review of crayfish color patterns in the Family Cambaridae (Astacoidea), with discussion of their possible importance

FIGURE 2. Lacunicambarus ludovicianus, right specimen from Alabama, left specimen from Missouri. Showing variation of prominent base color.

FIGURE 9 in Review of crayfish color patterns in the Family Cambaridae (Astacoidea), with discussion of their possible importance

FIGURE 9. Dorsal abdominal band variations found in Lacunicambarus aff. diogenes, Faxonius spinosus, Procambarus paeninsulanus, and Cambarus scotti.

FIGURE 12 in Review of crayfish color patterns in the Family Cambaridae (Astacoidea), with discussion of their possible importance

FIGURE 12. Variation in tail fan color patterns in Barbicambarus cornutus, Faxonius perfectus, Lacunicambarus diogenes, and Procambarus vioscai paynei.

FIGURE 11 in Review of crayfish color patterns in the Family Cambaridae (Astacoidea), with discussion of their possible importance

FIGURE 11. Variation in dorsal carapace saddle patterns in Barbicambarus cornutus, Cambarus lentiginosus, Faxonius durelli, Procambarus vioscai paynei, Faxonius cooperi, and Faxonius compressus.

opencc-zeroJul 2020View details →

Data from: Morphology, performance and fluid dynamics of the crayfish escape response

Sexual selection can result in an exaggerated morphology that constrains locomotor performance. We studied the relationship between morphology and the tail-flip escape response in male and female rusty crayfish (Faxonius rusticus), a species in which males have enlarged claws (chelae). We found that females had wider abdomens and longer uropods (terminal appendage of the tail fan) than males, while males possessed deeper abdomens and larger chelae, relative to total length. Chelae size was negatively associated with escape velocity, whereas longer abdomens and uropods were positively associated with escape velocity. We found no sex-specific differences in maximum force generated during the tail flip, but uropod length was strongly, positively correlated with tail-flip force in males. Particle image velocimetry (PIV) revealed that the formation of a vortex, rather than the expulsion of fluid between two closing body surfaces, generates propulsion in rusty crayfish. PIV also revealed that the pleopods (ventral abdominal appendages) contribute to the momentum generated by the tail. To our knowledge, this is the first confirmation of vortex formation in a decapod crustacean.

opencc-zeroJan 2021View details →

Stable resource polymorphism along the benthic littoral-pelagic axis in an invasive crayfish

Although intraspecific variability is now widely recognized as affecting evolutionary and ecological processes, our knowledge on the importance of intraspecific variability within invasive species is still limited. This is despite the fact that quantifying the extent of within-population morphological divergences associated with the use of different trophic or spatial resources (i.e. resource polymorphism) can help to better predict their ecological impacts on recipient ecosystems. Here, we quantified the extent of resource polymorphism within populations of a highly invasive species, Procambarus clarkii, in 16 lake populations by comparing their trophic (estimated using stable isotope analyses) and morphological characteristics between individuals from the littoral and pelagic habitats. Our results first demonstrated that crayfish occur in both littoral and pelagic habitats of 7 lakes and that the use of pelagic habitat was associated with increased abundance of crayfish in the littoral habitat. We then found that individuals from littoral and pelagic habitats displayed significantly different body and chelae morphology and origin of resource use (i.e. reliance on littoral carbon). These results demonstrate the existence of resource polymorphism in invasive populations. There was no genetic differentiation between individuals from the two habitats, implying that this resource polymorphism was stable (i.e. high gene flow between individuals). Finally, we demonstrated that a divergent adaptive process was responsible for the morphological divergence in body and chela shapes btween habitats while difference in origin of the resource use neutrally evolved under genetic drift. These findings demonstrated that invasive P. clarkii can display strong within-population phenotypic variability in recent populations, and this could lead to contrasted ecological impacts between littoral and pelagic individuals.

opencc-zeroDec 2018View details →

Data from: Monitoring a Norwegian freshwater crayfish tragedy - eDNA snapshots of invasion, infection and extinction

1.The European Noble crayfish (Astacus astacus) is threatened by crayfish plague caused by the oomycete Aphanomyces astaci, which is spread by the invasive North American crayfish (e.g. signal crayfish, Pacifastacus leniusculus). Surveillance of crayfish plague status in Norway has traditionally relied on the monitoring survival of cage‐held noble crayfish, a method of ethical concern. Additionally, trapping is used in crayfish population surveillance. Here we test whether environmental DNA (eDNA) monitoring could provide a suitable alternative to the cage‐method, and a supplement to trapping. 2.We took advantage of an emerging crayfish plague outbreak in a Norwegian watercourse following illegal introduction of disease‐carrying signal crayfish, and initiated simultaneous eDNA‐monitoring and cage‐based surveillance, supplemented with trapping. A total of 304 water samples were filtered from several sampling stations over a four year period. eDNA data (species‐specific qPCR) for the presence of A. astaci, noble and signal crayfish within the water samples were compared to cage mortality and trapping. 3.This is the first study comparing eDNA‐monitoring and cage‐surveillance during a natural crayfish plague outbreak. We show that eDNA‐monitoring corresponds well with the biological status measured in terms of crayfish mortality and trapping results. eDNA analysis also reveals the presence of A. astaci in the water up to 2.5 weeks in advance of the cage‐method. eDNA estimates of A. astaci concentration and noble crayfish numbers increased markedly during mortality, and vanished quickly thereafter. eDNA provides a snapshot of the presence, absence or disappearance of crayfish regardless of season, and constitutes a valuable supplement to the trapping‐method that relies on season and legislation. 4.Synthesis and applications. Simultaneous eDNA‐monitoring of Aphanomyces astaci (crayfish plague) and relevant native and invasive freshwater crayfish species is well‐suited for early‐warning of invasion or infection, risk assessments, habitat evaluation and surveillance regarding pathogen and invasive/native crayfish status. This non‐invasive, animal‐welfare friendly method excludes the need for cage‐held susceptible crayfish in disease‐monitoring. Further, eDNA‐monitoring is less likely to spread A. astaci than traditional methods. This study resulted in the implementation of eDNA‐monitoring for Norwegian crayfish plague and crayfish surveillance programmes, and we believe other countries could improve management strategies for freshwater crayfish using a similar approach.

opencc-zeroDec 2015View details →

Data from: Australian spiny mountain crayfish and their temnocephalan ectosymbionts: an ancient association on the edge of coextinction?

Australian spiny mountain crayfish (Euastacus, Parastacidae) and their ecotosymbiotic temnocephalan flatworms (Temnocephalida, Platyhelminthes) may have co-occurred and interacted through deep time, during a period of major environmental change. Therefore, reconstructing the history of their association is of evolutionary, ecological, and conservation significance. Here, time-calibrated Bayesian phylogenies of Euastacus species and their temnocephalans (Temnohaswellia and Temnosewellia) indicate near-synchronous diversifications from the Cretaceous. Statistically significant cophylogeny correlations between associated clades suggest linked evolutionary histories. However, there is a stronger signal of codivergence and greater host specificity in Temnosewellia, which co-occurs with Euastacus across its range. Phylogeography and analyses of evolutionary distinctiveness (ED) suggest that regional differences in the impact of climate warming and drying had major effects both on crayfish and associated temnocephalans. In particular, Euastacus and Temnosewellia show strong latitudinal gradients in ED and, conversely, in geographical range size, with the most distinctive, northern lineages facing the greatest risk of extinction. Therefore, environmental change has, in some cases, strengthened ecological and evolutionary associations, leaving host-specific temnocephalans vulnerable to coextinction with endangered hosts. Consequently, the extinction of all Euastacus species currently endangered (75%) predicts coextinction of approximately 60% of the studied temnocephalans, with greatest loss of the most evolutionarily distinctive lineages.

opencc-zeroDec 2016View details →

Data from: Phylogenetic evidence from freshwater crayfishes that cave adaptation is not an evolutionary dead-end

Caves are perceived as isolated, extreme habitats with a set of uniquely specialized biota, which long ago led to the idea that caves are 'evolutionary dead-ends.' This suggests that cave-adapted taxa may be doomed for extinction before they can diversify or transition to a more stable state. However, this hypothesis has not been explicitly tested in a phylogenetic framework with multiple independent cave-dwelling groups. Here we use the freshwater crayfish, a group with dozens of cave-dwelling species in multiple lineages, as a system to test this hypothesis. We consider historical patterns of lineage diversification and habitat transition as well as current patterns of geographic range size. We find that while cave-dwelling lineages have small relative range sizes and rarely transition back to the surface, they exhibit remarkably similar diversification patterns to those of other habitat types and appear to be able to maintain a diversity of lineages through time. This suggests that cave-adaptation is not a 'dead-end' for freshwater crayfish, which has positive implications for our understanding of biodiversity and conservation in cave habitats.

opencc-zeroDec 2017View details →

Data from: Genetic diversity and parasite facilitated establishment of the invasive signal crayfish (Pacifastacus leniusculus) in Great Britain

Successful establishment of non‐native species is strongly influenced, among other factors, by the genetic variation of founding populations, which can be enhanced by multiple introductions through admixture. Coexisting pathogens can also facilitate the establishment of non‐native species by detrimentally impacting on the native fauna acting as novel weapons. The signal crayfish (Pacifastacus leniusculus) is a highly invasive species, which has caused mass declines of native crayfish in Europe through displacement and transmission of the oomycete Aphanomyces astaci (crayfish plague), which is typically lethal to native European crayfish. However, whether Aphanomyces astaci may have facilitated the invasion of the signal crayfish is not known. We estimated the genetic diversity at microsatellite DNA loci, effective population size, and potential origins of seven infected and noninfected signal crayfish populations in Europe and one founder population in North America. Approximate Bayesian computation analysis and population structuring suggested multiple host introductions from diverse source populations, as well as higher heterozygosity among infected than uninfected populations, which could reflect a fitness advantage. Low effective population size, moderate heterozygosity, and lack of isolation by distance suggest that some invasive signal crayfish populations may not be fully established or that their genetic diversity may have been reduced by eradication attempts.

opencc-zeroDec 2015View details →

Data from: Environmental DNA (eDNA) detects the invasive rusty crayfish (Orconectes rusticus) at low abundances

Early detection is invaluable for the cost-effective control and eradication of invasive species, yet many traditional sampling techniques are ineffective at the low population abundances found at the onset of the invasion process. Environmental DNA (eDNA) is a promising and sensitive tool for early detection of some invasive species, but its efficacy has not yet been evaluated for many taxonomic groups and habitat types. We evaluated the ability of eDNA to detect the invasive rusty crayfish Orconectes rusticus, and to reflect patterns of its relative abundance, in upper Midwest, USA inland lakes. We paired conventional baited trapping as a measure of crayfish relative abundance with water samples for eDNA, which were analysed in the laboratory with a qPCR assay. We modelled detection probability for O. rusticus eDNA using relative abundance and site characteristics as covariates, and also tested the relationship between eDNA copy number and O. rusticus relative abundance. We detected O. rusticus eDNA in all lakes where this species was collected by trapping, down to low relative abundances, as well as in two lakes where trap catch was zero. Detection probability of O. rusticus eDNA was well-predicted by relative abundance of this species and lake water clarity. However there was poor correspondence between eDNA copy number and O. rusticus relative abundance estimated by trap catches. Synthesis and applications. Our study demonstrates a field and laboratory protocol for eDNA monitoring of crayfish invasions, with results of statistical models that provide guidance of sampling effort and detection probabilities for researchers in other regions and systems. We propose eDNA be included as a tool in surveillance for invasive or imperilled crayfishes and other benthic arthropods.

opencc-zeroNov 2019View details →

Data from: Urbanization and population genetic structure of the Panama City crayfish (Procambarus econfinae)

For species with geographically restricted distributions, the impacts of habitat loss and fragmentation on long-term persistence may be particularly pronounced. We examined the genetic structure of Panama City crayfish (PCC), Procambarus econfinae, whose historical distribution is limited to an area approximately 145 km2, largely within the limits of Panama City and eastern Bay County, Florida, USA. Currently, PCC occupy approximately twenty-eight percent of its historical range, with suitable habitat composed of fragmented patches in the highly urbanized western portion of the range and managed plantations in the more contiguous eastern portion of the range. We used 1,640 anonymous single nucleotide polymorphisms to evaluate the effects of anthropogenic habitat modification on the genetic diversity and population structure of 161 PCC sampled from across it known distribution. First, we examined the urban habitat patches in the west compared to less-developed habitat patches in the east. Second, we used Approximate Bayesian Computation to model inferences on the demographic history of eastern and western populations. We found anthropogenic habitat modifications explain the genetic structure of PCC range-wide. Clustering analyses revealed significant genetic structure between and within eastern and western regions. Estimates of divergence between east and west were consistent with urban growth in the mid-20th Century. PCC have low genetic diversity and high levels of inbreeding and relatedness, indicating populations are small and isolated. Our results suggest that PCC have been strongly affected by habitat loss and fragmentation and management strategies, including legal protection, translocations, or reintroductions, may be necessary to ensure long-term persistence.