Abstracts

IAA22 Book of Abstracts (PDF)

Meeting Program/Schedule (PDF)

 

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LIST OF MEETING ABSTRACTS

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Oral | Posters


Oral Presentations

 

 

Day: 2, Session: 1, Talk: 3

Welcome Address

James W. Fetzner Jr. and Eric Dorfman

Welcome Address

 

 

Day: 2, Session: 1, Talk: 4

HOST COUNTRY LECTURE:
An Overview of U.S. Crayfish Conservation in State Agencies and a Plan to Reverse CRAWnic Neglect

Robert J. DiStefano

Crayfish conservation can be accomplished in the United States (U.S.) by federal government, state governments, universities, non-governmental organizations (i.e., The Nature Conservancy), professional societies (e.g., American Fisheries Society), local governments, and private citizens. State fish and wildlife agencies are charged with protecting and managing each state’s aquatic resources, yet crayfish have historically received little attention from them. This is largely due to state funding formulas that rely heavily on sales of recreational licenses (fishing, hunting, etc.), and perceived responsibility of agencies to be more responsive to that segment of the public who buy licenses. Missouri is unique in having established a state conservation program for crayfish decades ago. The program has produced substantial research data on crayfish species distributions, ecology and threats, especially for imperiled and endemic species. It has yielded several conservation actions (e.g., regulations, education products and activities). I will reference Missouri as one possible model for establishing and maintaining a state government (or regional government elsewhere) crayfish conservation program that involves government staff, but also partners from academia and some stakeholder groups. I will conclude by providing a brief update about states’ involvement in U.S. crayfish conservation.

 

 

Day: 2, Session: 2, Talk: 3

Cambarus aff. dubius, a New Species of Crayfish (Decapoda: Cambaridae) Endemic to the Pre-glacial Teays River Valley in West Virginia, USA

DAVID A. FOLTZ II., Nicole M. Sadecky, Greg A. Myers, James W. Fetzner Jr., Stuart Welsh, G. Whitney Stocker, Mael G. Glon and Roger F. Thoma

A new species of crayfish, Cambarus aff. dubius, new species, is described from the preglacial Teays River Valley of Cabell, Kanawha, Lincoln, Mason, and Putnam counties, West Virginia. The species was previously considered to be part of the Cambarus dubius complex (Jezerinac et al. 1995). Loughman et al. 2015 restricted C. dubius to an orange color morph found in central and northern portions of the Allegheny Mountains and Appalachian Plateau in central West Virginia, western Maryland, and southcentral Pennsylvania. The new species described herein can be distinguished from all other members of Cambarus by a double row of cristiform tubercles on the palm, an open areola with two rows of punctations, and a consistent blue coloration.

 

 

Day: 2, Session: 3, Talk: 7

Introduced and Then Almost Forgotten: Invasive Crayfish (Procambarus clarkii and Cherax quadricarinatus) in Costa Rica, Central America - Preliminary Results

JUAN CARLOS AZOFEIFA SOLANO, Ingo S. Wehrtmann, Fresia Villalobos-Rojas, Raquel Romero-Chaves and Adrián García-Rodríguez

Costa Rica harbors a remarkable diversity of freshwater native decapods, including 15 crab species (Pseudothelphusidae) and more than 21 species of caridean shrimps (Atyidae and Palaemonidae). Crayfish (Astacoidea) are not part of the native freshwater decapod fauna of the country. However, during the last century, two crayfish species were introduced: Procambarus clarkii in the Reventazón basin (Caribbean slope) in the 1970's, and Cherax quadricarinatus in the Tempisque basin (Pacific slope) in the 1980's. Both species have been recognized as invasive species in many other countries, and there is broad evidence suggesting its negative impact on native species, ecosystem functioning, and even human activities. Despite the potential threat of these crayfish species for the Costa Rican freshwater environments, very limited information is available about their occurrence in the country. Therefore, it is imperative to document the current distribution of both species and to assess their possible effects on the freshwater ecosystems in Costa Rica. We initiated a study aimed to explore the presence of these invasive crayfish species in Costa Rican streams and lakes and to provide information about their feeding ecology. So far, we have collected P. clarkii in two locations, outside the Reventazón basin were it was initially introduced, and belonging to the Pacific slope. More than 160 specimens have been analyzed, ranging in size from 6.5 to 78.1 mm total length. The predominant food item found at the stomachs was unidentified plant detritus, followed by filamentous plants, fragments of chironomid and Ephemeroptera larvae, and plastic. Our collections revealed two new locations for C. quadricarinatus in Costa Rica: one of them a stream in the Caribbean slope, and the other in the Arenal Lake, the largest reservoir in Costa Rica. The size of the collected specimens (n=7) ranged from 45.1 to 92.2 mm total length. Currently, both crayfish species inhabit both Caribbean and Pacific slopes in Costa Rica. It remains to be studied whether these species dispersed naturally or if they were locally introduced by humans. Since both species have been introduced in Costa Rica and the Central American region, the results of the study aim to raise awareness about the possible impacts of these crayfish species on the native flora and fauna of the local freshwater ecosystems, and to develop recommendations for the implementation of management programs.

 

 

Day: 2, Session: 4, Talk: 1

Illegal Export of Australian Freshwater Crayfish – Intercepted Shipments: A Case of Euastacus

James M. Furse

The unique, and often remarkable, nature of the native flora and fauna of Australia is well known. Many of these native Australian species are highly attractive, desirable and sought-after by private collectors, but also commercial interests known to include the pet/aquarium, and restaurant and gourmet food trades. Live export of native Australian wildlife (i.e. amphibians, birds, mammals, reptiles) for commercial purposes is prohibited under any circumstances. Live export of some invertebrates, fish and plants may be permitted (for commercial purposes), if they originate from approved sources or programs (i.e. captive breeding, aquaculture, or wildlife trade/wildlife trade management plans). For non-commercial purposes live exports of native flora and fauna is permitted (e.g. research, education), but as with any type of native species export, this is strictly regulated. Illegal export of Australian native flora and fauna is a most serious (and Federal) offence: penalties can be very serious indeed. Despite this, it is well established that there is illegal and ongoing "leakage" of native Australian flora and fauna. The freshwater crayfish fauna of Australia is both unique, remarkable, and well known in the aquarium trade. In some regions of the World this fauna is also evidently known in the restaurant and gourmet food trade. Illegal export(s) of native species of freshwater crayfish have previously occurred, and ongoing illegal exports of these animals are suspected, and sadly also expected. This talk will briefly outline the rules and regulations limiting live exports of native Australian flora and fauna, and outline case(s) of apparent illegal exports of Australian freshwater crayfish. A recent case where an illegal shipment of Euastacus was intercepted, and seized, in Australia will be discussed. This discussion will include information on the species that was intercepted, the intended geographical destination, destination-industry and why such activities pose a very serious threat to such species. Other details surrounding the intercepted shipment will be outlined as may be appropriate.

 

 

Day: 3, Session: 3, Talk: 3

Multi-method Inference of Temperature Tolerance and Preference for a Native and an Invasive Crayfish

JACOB T. WESTHOFF, Chris Rice, Hisham Abdelrahman and James A. Stoeckel

Conservation and management of crayfishes can be informed through a greater understanding of crayfish thermal ecology, especially as it relates to the suitability of thermal habitats for native and invasive crayfish. We used a combination of behavioral and enzymatic endpoints to estimate temperature preference, optimal respiratory enzyme tolerance (ORET), and critical thermal maximum (CTM) for the imperiled native Coldwater Crayfish (Faxonius eupunctus) and the invasive Ringed Crayfish (Faxonius neglectus). Significant differences in these parameters would allow for thermal partitioning of space and thus enhance the probability of coexistence. Crayfish used in CTM and preference tests were acclimated at one of four temperatures (10, 15, 20, 25°C) for two weeks prior to testing, whereas ETS assays used crayfish acclimated at 21°C. Estimates of CTM were 33.9°C for F. eupunctus and 33.2°C for F. neglectus. Mixed linear model analysis of CTM data showed no difference between species or genders, but a strong effect of acclimation temperature (p-value < 0.01). Mixed linear model analysis using likelihood ratio tests indicated F. eupunctus preferred slightly colder water (19.6°C) than did F. neglectus (21.3°C; p-value = 0.03). That analysis also identified a significant difference (p-value = 0.01) between males (20.3°C) and females (21.0°C), but acclimation temperature and the interaction between gender and species were not significant. Mean ORET did not differ between F. eupunctus (28.4°C) and F. neglectus (28.5°C), but did differ from a third congener, Faxonius marchandi (29.7°C), based on two-way ANOVA results. For all species, ORET was higher than organismal thermal preference estimates, but lower than CTM, suggesting it may provide a useful breakpoint for managers. Management strategies should target temperature regimes that approach but do not exceed OET to increase the frequency of optimal temperature occurrences while minimizing the risk of exposing crayfish to their thermal maxima. Across all estimated metrics, F. eupunctus and F. neglectus differed by less than 2°C, indicating that significant biological difference is unlikely. Thus, habitats suitable for the native F. eupunctus will also be thermally available to the invasive F. neglectus, thereby increasing the opportunity for interaction and negative population effects.

 

 

Day: 3, Session: 3, Talk: 5

Hunting Missouri’s Rarest Crayfish Using eDNA and Visual Surveys: A First Look at the Natural History of the Caney Mountain Cave Crayfish

ROBERT J. DiSTEFANO, David C. Ashley, Shannon K. Brewer and Joshua B. Mouser

Stygobitic (cave) crayfishes are regarded as the most imperiled crayfishes in the U.S. and Canada. The Caney Mountain Cave Crayfish (Faxonius stygocaneyi), discovered in 1998, is known from only a single population in Mud Cave in the Caney Mountain Conservation Area (CMCA) of southern Missouri. It is listed as “critically imperiled” by the state of Missouri and “threatened” by the American Fisheries Society. We conducted the first study of F. stygocaneyi to gather preliminary data on its natural history and population, and to locate possible additional populations. We visited Mud Cave on 14 occasions (at least once each season) between 2014 and 2018. Visual surveys along a transect of inundated (wet) and non-inundated (mud) habitat were conducted during most visits except late April-May 2017 when the cave was flooded. Supplemental baited trapping was also performed intermittently. Water samples (2 L at two Mud Cave locations) were taken on each of 7 visits in 2017 and 2018. Water and air temperatures were recoded for most of 2014-2016. We captured a total of 23 (carapace length, 15.0-47.0 mm, average: 27.2 mm) and observed an additional 42 F. stygocaneyi, including the first-ever records of juveniles (August 2016 and 2017) and an ovigerous female (August 2016). Multiple visual searches of the known five other caves and three springs at CMCA detected no F. stygocaneyi. In addition to water samples from Mud Cave, we also collected and filtered multiple water samples from Onyx, and Bear Hollow caves, and three springs thought to be in the same drainage in 2017-2018. We developed primers and probes to amplify F. stygocaneyi DNA from those samples. Study results were limited by use of non-invasive sampling methods, high turbidity, flooding on some occasions, and what appears to be a small population. Yet we observed four times more crayfish compared to the previous 17 years since the species’ discovery, and collected the first biological data. Visual and eDNA sampling of adjacent caves and springs suggest the species could be endemic to only Mud Cave.

 

 

Day: 3, Session: 4, Talk: 4

Effect of an Analgesic at Environmental Concentration on Crayfish Locomotion and Cardiac Physiology

FILIP LOŽEK, Iryna Kuklina, Tomáš Randák, Pavel Kozák, Petr Císař and Miloš Buřič

There is an increasing evidence on ecological and biological impacts of pharmaceutical pollution (e.g., antidepressants, anxiolytics, psycholeptics and analgesics) on aquatic organisms. Tramadol is an example of opioid analgesic frequently used treating chronic and acute pain. In order to investigate long-time effects of tramadol at environmentally relevant of 1 ?g L-1 on signal crayfish Pacifastacus leniusculus as an important participent of the predator-prey relationships, cardiac activity (heart rate, HR) and behavior (locomotion) were evaluated under repeated stimuli of a natural stressor (i.e., hemolymph) as an odor of injured conspecific 4 times within 3 weeks of tramadol exposure and 4 times within following 2 weeks of depuration period. For evaluation of crayfish primary physiological and ethological reactions to the stressor, the data within half an hour prior to and half an hour post stressor addition were used. A significant increase of the HR after stressor application was found, as well as there was a significant difference between tramadol free (control) and tramadol exposed groups. However there was no statistical difference in the locomotion of both control and exposed crayfish recorded before and after stressor application. According to the discovered shifts in crayfish cardiac physiology under long-term exposure to tramadol at non-lethal concentration, the significance of these shifts will need further detailed investigations.

 

 

Day: 5, Session: 3, Talk: 3

Observations of Chelae Injury in Two Crayfish Species in Three Sinuous Rills

CHESTER R. FIGIEL JR.

Crayfish often lose or autotomize limbs (e.g., chelae) during agonistic conflicts. This defense mechanism increases the probability of surviving the encounter, however can result in long-term functional and energetic costs. For example, chela autotomy influences crayfish competitive ability, foraging time, capacity to obtain mates, and modifies crayfish distribution and behavior. Biotic factors (e.g., population density or predators), as well as abiotic factors (e.g., refugia or habitat complexity) can influence the frequency of injury. In this study, I investigated the prevalence of chela injury (loss or partially regenerated chelae) in two crayfish species (Cambarus striatus and Procambarus spiculifer) that were collected in three sinuous rills (Mountain Creek (MC), Liberty Bell Creek (LB), and Cascade Branch (CB)) in west central Georgia, USA over a four year period. My objectives were to determine if injury was similar among sites, among crayfish species, or varied with time of year. Additionally, within a species my objectives were to examine whether injury differed in crayfish size classes or sex. Cambarus striatus were collected in each of the three streams with the percent injured as follows: MC 15.5%, n = 579; LB 16.3%, n = 1555; and CB 21.3%, n = 1159. There were significantly more injuries from crayfish collected at CB than at the other two streams (p < 0.05). This was most likely driven by the greater percent of injuries in the juvenile size classes (6.0 mm to 15.9 mm carapace length (CL)): CB (24.5%) compared to the similar size classes at LB (16.6%) and MC (15.0%). The frequency of injury between males (18.2%), females (20.0%), or juveniles (19.0%) did not differ significantly nor were there significant differences between Form I (15.6%) and Form II (18.9) males (p > 0.05). Of the 590 C. striatus crayfish having an injury, approximately 13% of these crayfish had both chelae injured. Procambarus spiculifer were collected in each of the three streams (however only 3 individuals were collected at LB so data were not used for that site). The percent injured for P. spiculifer differed significantly between MC 12.1%, n = 727; and CB 23.7%, n = 169 (p < 0.05). There were a greater percent of injuries in the larger adult size classes (> 31.0 mm CL = 26.4%) compared to smaller size classes (< 31.0 mm CL = 9.9%). The frequency of injury among males (13.8%) and females (15.9%) did not differ significantly, however differed from the percent of injured juvenile crayfish (7.3%). Of the 126 P. spiculifer crayfish having an injury, approximately 12% of these crayfish had both chelae injured. The percent of injured crayfish captured varied widely from month to month for both species and no discernable pattern emerged through time. Given the level of injury in these populations, it is vital to understand how injury influences population dynamics of these two species with differing ecological needs and lifestyles.

 

 

Day: 5, Session: 4, Talk: 1

Origin and Speciation of the Marbled Crayfish

FRANK LYKO

Marbled crayfish are a globally expanding population of parthenogenetically reproducing freshwater crayfish. They are closely related to the sexually reproducing slough crayfish, Procambarus fallax, which is native to the southeastern United States. However, reproductive incompatibility and substantial genetic differences suggest that the marbled crayfish should be considered an independent species (Procambarus virginalis). We have recently established a draft assembly of the marbled crayfish genome. We are now using comparative whole-genome sequencing to clarify the origin and speciation of marbled crayfish and I will discuss our available data.


 

Poster Presentations

 

 

POSTER 59

Survey Says: U.S. State- and Canadian Provincial-Level Natural Resource Agencies Focus on Crayfish Conservation

Cheyenne E. Stratton and ROBERT J. DISTEFANO

Taylor et al. (1996) issued a "warning shot" about a crayfish imperilment plight, and "neglect" of the fauna by natural resources agencies. In the ensuing decades some highly imperiled aquatic faunal groups, such as unionid mussels and crayfish, have received moderately increased attention by U.S. and Canadian natural resources agencies. Such attention appears to have translated to increased funding for work on crayfish, possibly due to concern for individual species' imperilment, or resource problems caused by them (e.g., invasive crayfishes). We wondered 1) how perceived increased agency attention to crayfish might be reflected in numbers and types of staff assigned to work on crayfish conservation and management?, 2) where (topically) these staff are directing their efforts?, and 3) what are agencies' major constraints/impediments to and needs for crayfish conservation and management? We conducted a two-part telephone survey in 2017 and 2018 to learn about natural resources agencies' level of involvement and direction in crayfish conservation and management. In Part I (2017) we called natural resource agencies in all 50 U.S. states and 13 Canadian provinces/territories (63 "jurisdictions") to determine the number who employed or contracted staff to work on crayfish, where these jurisdictions were located (regionally), and in what topical/subject areas they were working. In Part II (2018) we made follow-up calls to only jurisdictions that had reported doing crayfish work in Part I of the survey. We asked them about their agencies' prioritization of crayfish, impediments to crayfish work, and information they believed most useful to help them conserve/manage crayfish (data needs). Part I results indicated nearly half of jurisdictions are conducting crayfish work, mostly in the Southeastern U.S., and concentrating on determining species' distributions and conservation status, or on threats (i.e., invasive species). Part II suggested that more than half of agencies working on crayfish consider them a priority faunal group, with the largest impediment being insufficient funding. Jurisdictions' most commonly cited information needs were species compositions (native and introduced), distributions, conservation status assessments, ecology, and threats. Our survey results suggest an encouraging but limited increase in U.S. state and Canadian provincial/territorial natural resources agencies working on crayfish since Taylor et al.'s (1996) challenge.

 

 

POSTER 60

Identification of Pathogens Causing Porcelain Disease in North America: Call for Samples

EMILY IMHOFF

Porcelain disease refers to the appearance of certain symptoms in crayfish, primarily a white opacity of the musculature. The disease is usually slow-progressing but believed to be fatal in all cases. In crayfish it is typically caused by microsporidians of the Thelohania genus. However, the symptoms may also be caused by members of other genera. Species identifications are currently made by morphology and more importantly through genetic techniques. Porcelain disease is well documented in European and Australian crayfish populations, but has not been well-studied in North America where anecdotal evidence suggests it occurs at a low rate in wild crayfish populations. I hope to acquire samples of infected crayfish from field researchers in North America to identify the species of microsporidians causing the disease on this continent. I am looking for assistance with this project from any researchers in North America who encounter visibly-infected crayfish and are willing to provide a tissue sample for investigation. Sampling kits will be made available for any willing participants.

 

 

POSTER 62

Habitat Associations of Endemic Crayfishes in the Meramec River Drainage: The Freckled Crayfish (Cambarus maculatus) and Belted Crayfish (Faxonius harrisonii).

Joe Chilton, Amanda E. Rosenberger and ROBERT J. DiSTEFANO

Understanding the habitat associations of rare species is important to make informed management and policy decisions. The Freckled Crayfish (Cambarus maculatus) and Belted Crayfish (Faxonius harrisonii) are two of Missouri’s rare and endemic crayfish species. Both species are listed as vulnerable on Missouri’s list of species and communities of conservation concern due to their limited range. Their native range is limited to the Meramec River drainage in eastern Missouri. We sampled 60 sites throughout the two species’ known range for presence and habitat variables. Replication was performed spatially within sites using kick-seines, drag seines, and visual timed-searches. Local- and landscape-scale habitat variables were evaluated for possible associations with the crayfishes through occupancy modeling with the R package “unmarked”. We found boulders and Strahler stream order were positive estimators of occupancy, while percent agriculture was negatively associated with the Freckled Crayfish. Belted Crayfish were associated with larger substrate size, increased embeddedness of substrate, and aquatic vegetation. This information will guide conservation managers in future projects and policy decisions regarding these two species.

 

 

POSTER 67

Another Cautionary Tale of Numts: Multiple Different Copies of the COI Gene in the Camp Shelby Burrowing Crayfish (Fallicambarus gordoni)

JAMES W. FETZNER JR.

During a preliminary phylogeographic study conducted several years ago involving the Camp Shelby Burrowing Crayfish (Fallicambarus gordoni) it was noted that most of the generated COI barcode sequences were “messy” (i.e., contained multiple peaks at many sites along the length of the sequence), suggesting some sort of contamination was being co-amplified. This messy data was so prevalent (almost every specimen) that it ultimately eroded confidence in the base calls for the region sequenced and led to the termination of the project due to a very limited sequencing budget that had already been expended. In order to investigate the source of this contamination, COI PCR products from eight F. gordoni individuals (one from each sampled site), plus one specimen of another Fallicambarus species, were subsequently cloned. Eight individual colonies per individual were picked, amplified, and sequenced to see if the source of the contamination could be identified (i.e., as bacterial, human, pseudogene, or other). Checking the sequences using Genbank BLAST searches revealed that the sequences were most closely related to COI genes from the genus Fallicambarus, suggesting they are additional copies present within the genome, rather than contaminant DNA from an external source (i.e., bacterial). The results suggested that multiple different copies of the COI gene appear to be present within the genome of F. gordoni individuals, often containing multiple point mutations and/or length differences (=indels), which directly resulted in the messy sequences seen during the original project. In some cases, the sequences appeared to be pseudogenes because they often contained multiple stop codons. This study provides another cautionary tale about numts (nuclear copies of mitochondrial genes) and making sure they are accounted for when analyzing mitochondrial datasets in phylogeographic and systematic studies of freshwater crayfish.

 

 

POSTER 77

The Crayfish Morphology Database: Developing an Online Platform for Maintaining and Sharing Specimen Data and Images Used in the Descriptions of New Crayfish Species

JAMES W. FETZNER JR.

A new online database, and associated website, are under development with the goal of capturing, maintaining and sharing a standard suite of morphological measurement data and specimen images used in the description of new freshwater crayfish species. The website is password protected, allowing authors to secure their project data under a user account that only they can access. Once published, their data could become available to the community. The site consists of eight tabbed web forms that capture information on field collections, geographic locality, and specimen-level morphological measurements broken out by major feature (e.g., Carapace, Rostrum, Chela, Gonopod, and ‘Miscellaneous’). A tab is also provided to upload specimen images captured from a variety of views. The database currently is set up for capturing data on North American taxa, but if there is interest from the community, this could be expanded to include other crayfish groups from around the globe. Measurement data can be entered automatically into the web form via a digital caliper connected to a computer, or entered manually. A standard set of photographic images can also be captured and annotated, and then uploaded to the project, making them available for side-by-side viewing, allowing for multiple specimen comparisons of various morphological features. Features such as simple statistical analyses of the data (counts, frequencies, etc.) still need to be implemented, but could be generated and output as a summary report. The full project data can also be output to Excel format to allow for more detailed statistical analyses. Most of the data presented in new species descriptions are just estimates of the mean and/or the range of values measured. Thus, all of the underlying data captured for each individual specimen in a study are often lost to science, unless the specimens have been designated as types. Having a repository for these types of data will help to make comparisons among species a lot easier in the future and will reduce the duplication of effort when making comparisons among multiple species.


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