IAA22 Book of Abstracts (PDF)

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Oral | Posters

Oral Presentations



Day: 2, Session: 4, Talk: 5

The Distribution and Conservation Status of the White Colour Morph of the Northern Clearwater Crayfish (Faxonius propinquus) in Lake Simcoe, Ontario, Canada

PREMEK HAMR and Mark Hoel

The rare and endemic white morph of Faxonius propinquus was first identified and described in 1978 by Dunham and Jordan who also subsequently documented the presence and distribution of the other various species and two other colour morphs of F. propinqqus in Lake Simcoe in Southern Ontario. Since then, no further research has been conducted on these populations, and the lake has been invaded by the introduced Rusty crayfish (Faxonius rusticus). The present study documents the decline and the present distribution of not only the rare white morph but also the other resident native species (O. virilis) which also appears to display several unusual colour morphs in Lake Simcoe. The decline of all three morphs of Faxonius propinquus as well as the impact of the F. rusticus expansion in the lake were assessed through surveys during the summers of 2015, 2016 and 2017. The significance of the results is discussed with respect to the conservation status and the future management of native crayfishes in Lake Simcoe.



Day: 5, Session: 2, Talk: 4

Using Crayfish as a Bio-indicator – Practical Experience from a Brewery Factory

PAVEL KOZÁK, Viktoria Shchennikova, Filip Ložek, Iryna Kuklina, Michal Vold?ich, Roman Dedic and Petr Císa?

We operated our patented non-invasive monitoring system using crayfish as a bio-indicators to control the water quality at the brewery factory. The system is based on monitoring of etho-physiological status of crayfish combining analysis of the heart rate and detection of movement as basic parameters. Monitoring of cardiac activity is done with the aid of a non-invasive sensor connecting crayfish by a flexible wire to the measuring unit and the locomotion is registered by cameras that enable complex analysis of the data by a software developed particularly for this purpose. The system was established in the water treatment facility of the factory in spring 2016. The period from February to August 2017 was precisely analyzed with the focus on the effect of water hygienic treatment with chlorine dioxide (ClO2) on crayfish heart rate and their subsequent mortality. Adult individuals of signal crayfish, Pacifastacus leniusculus, were kept separately in flow through aquariums, placed following the water treatment device producing ClO2 in concentration from 0.01 to 0.29 mg·L-1. Observed crayfish response to disinfectant varied among specimens that could be explained by different physiological conditions and individual reaction. Diurnal rhythm of some crayfish was disturbed even at lowest concentrations of chlorine dioxide (0.01-0.2 mg·L-1), that resulted in interruption of circadian cardiac and locomotor activity, while higher concentrations (? 0.2 mg·L-1) affected all animals and in addition to that, mortality significantly increased. The highest concentrations (0.2-0.29 mg·L-1) were observed 28 times in total during 202 days of monitoring, which resulted in 25 mortality cases occurred several days after exposure. In average, mortalities of crayfish occurred 3-4 weeks after stocking to the experimental system. Possible lethal concentration of ClO2, which caused animal mortality, exceeded 0.2 mg·L-1. Results suggested that crayfish exposure to ClO2, obviously, negatively affect their physiological processes; however, further studies are needed to examine specific effects of chlorine dioxide on internal organs of crayfish. Also, the results can serve the background data for an efficient crayfish application as biological indicators of appropriate disinfection at the water treatment and supply facilities.



Day: 5, Session: 2, Talk: 5

Invasive Rusty Crayfish (Orconectes rusticus) Populations in North America are Infected with the Crayfish Plague Disease Agent (Aphanomyces astaci)

JÖRN PANTELEIT, Thomas Horvath, Japo Jussila, Jenny Makkonen, William Perry, Ralf Schulz, Kathrin Theissinger and Anne Schrimpf

The American rusty crayfish, Orconectes rusticus, is an invasive species in various parts of North America, where it displaces resident crayfish species. While the influence of the crayfish plague disease agent, Aphanomyces astaci, has been studied extensively in Europe, the impact of A. astaci on the invasion success of crayfish within North America has so far received no attention. As a first approach to the question, whether A. astaci might play a role in the invasion success of O. rusticus within North America, we tested 84 O. rusticus samples for infection with A. astaci from 10 different locations in the Midwest, which are outside of the O. rusticus native distribution range. We used quantitative real-time PCR (qPCR) to assess the infection prevalence and determined the mitochondrial haplotypes and multilocus microsatellite genotypes where this was possible. With qPCR, we detected A. astaci DNA in 4 out of 10 locations. The results were confirmed by isolation of A. astaci. Analyses of the pure culture isolates and the crayfish tissue samples by haplotyping and genotyping revealed a novel microsatellite genotype. Our results clearly identify O. rusticus as a vector of A. astaci in North America for the first time. The threat caused by these novel strains to endangered crayfish species in North America still remains unknown, but conservation efforts should consider A. astaci infections when developing and implementing invasive species management plans.



Day: 5, Session: 4, Talk: 2

Monitoring Indigenous and Invasive Crayfish and Other Aquatic Species Using Educational Citizen Science and Environmental DNA

SUNE AGERSNAP, Steen Wilhelm Knudsen, Peter Rask Møller, Marie Rathcke Lillemark and Pernille Hjorth

The use of environmental DNA (eDNA) extracted from water samples is a promising tool for early and non-invasive detection of invasive and indigenous crayfish and other aquatic species. However, regular monitoring of large freshwater areas with eDNA are still quite labour intensive. In this presentation I will present preliminary results and experiences from Natural History Museum of Denmark’s citizen science based education program “DNA & LIFE”, where high school students, collect and analyse eDNA samples with the newest species-specific assays and methods. They work in a special DNA-laboratory with high procedural standards that has been established for education. This gives scientists an easy access to a high number of water samples from all over Denmark. At the moment in our “Real Science” project, students work together with scientist to develop and test new assays. During the development of the crayfish assays published in Agersnap et al. 2017. DNA and LIFE did some of the initial testing in 2015 on water samples, and has afterwards tested several waters for crayfish. Since DNA and LIFE started in 2014 more than 6,000 students have collected and analysed eDNA samples from more than 450 lakes and streams covering all of Denmark. And more than 40 different species-specific assays have been tested on freshwater and marine samples. These results can be beneficial to other scientific institutions who want to combine eDNA monitoring with scientific based, educational citizen science.



Day: 5, Session: 4, Talk: 3

Crustacyanin Genes of Cambarus Crayfish

PAUL R. CABE, Morgan Trimas, Jeronimo Reyes-Olmedo and Christian Kim

Decapod crustaceans, including crayfish, exhibit a tremendous range of coloration. These various colors are all produced by a combination of diet-derived carotenoid pigments with proteins coded by the crustacyanin genes, a crustacean-specific evolutionary innovation. In general, peptides from two different crustacyanin genes, crustacyanin A and crustacyanin C, combine in multi-unit proteins with carotenoids, shifting the absorption spectra of carotenoids to produce a range of colors. Despite their evolutionary and ecological importance, little is known about these genes in crayfish. We attempted to determine the sequence of these genes in Cambarus longulus and Cambarus bartonii (family Cambaridae) using an RNA-seq approach. RNA was extracted from tissues on the inner surface of the carapace (endocuticle, epithelium, hypodermis) and converted to cDNA. The cDNA pool was sequenced on the Illumina platform, yielding more than 7 million paired-end reads per species, which were assembled into transcripts. These transcripts were searched using crustacyanin sequences from other decapods. The sequence data suggest there are three different crustacyanin A genes in these species which differ primarily in non-coding regions. Using primers designed from these sequences, we were able to amplify these genes directly from genomic DNA, which confirmed the transcript sequences and revealed the presence of short introns. Likewise, the data also suggest both species have several distinct crustacyanin C genes. Direct knowledge of the sequence of these genes opens the possibility for comparative study of these evolutionary important genes in crayfish of the family Cambaridae.


Poster Presentations




Development of a Captive Rearing Protocol for Threatened & Endangered Appalachian Crayfish

CHRISTOPHER VOPAL, Emmy Delekta and Zachary J. Loughman

In 2016, two Appalachian endemic species were federally listed by the United States Fish & Wildlife Service: Cambarus callainus (Big Sandy Crayfish) and Cambarus veteranus (Guyandotte River Crayfish), which are listed as threatened and endangered respectively. Both species were listed due to limited and declining ranges caused by various anthropogenic activities, especially those causing stream sedimentation. Captive propagation can be used as a tool for crayfish conservation by helping to restore the native range of a species or improving their fecundity within their current range. Over a ten week period, 120 young-of-the-year (YOY) Cambarus chasmodactylus (New River Crayfish), a surrogate species for C. callainus and C. veteranus, were raised in individual cells to compare (1) growth and (2) survival on two different diets. They were fed every other day, with half (60) raised on trout diet pellets (TD) and the other half raised on blood worms (BW). Results showed more YOY growth with BW (17.3% growth) than with TD (13.6% growth). Increased survival was also observed with BW (84.5% survival) when compared to the TD (70.5% survival). Our results may be influenced by the ease and ability for the crayfish to forage on the blood worms and may also have a higher nutritional value in comparison to the TD. Our findings suggests a BW diet may be more effective in the captive rearing of Camabrus crayfish. Using information gathered from this study, a modified protocol will be used for a new study beginning July 2018 for C. callainus and Cambarus smilax (Greenbrier Crayfish). This modified protocol will compare three diets (bloodworm, detritus, and bloodworm/detritus) in the growth and survival of YOY C. callainus and C. smilax in a six month period.




Exploring the Limit and Beyond of Hypoxia: Behavioural-driven Conservation of an Ancestral Legacy of Freshwater Crayfish

LUCIAN PÂRVULESCU, Adrian Neculae, Eva Kaslik, Claudia Zaharia, Zanethia Barnett, Marcelo M. Dalosto, James M. Furse, Tadashi Kawai, Sandro Santos and Ovidiu I. Sîrbu

Freshwater crayfish burrowing is not simply sheltering, but an active and conscious behavior in which the animal invests considerable time and energy. As aerobic organisms, crayfish are often recorded as being related to high levels of dissolved oxygen. Approaches considering the in-burrow requirements of oxygen are scarce. We monitored the respiratory behavior and survival under acute hypoxia under controlled conditions in the laboratory of ten ecologically and phylogenetically dissimilar species of crayfish from different geographical locations (5 species of Cambaridae, 3 of Astacidae and 2 of Parastacidae). We found that primary burrowing species (Parastacus brasiliensis and Cambarus striatus) cannot tolerate severe hypoxia, whereas secondary and tertiary burrowing species (Faxonius limosus, F. etnieri, Procambarus vioscai, Cambaroides japonicus, Austropotamobius torrentium, Astacus leptodactylus, A. astacus and Cherax quadricarinatus) were not only able to withstand prolonged anoxia, but also able to remain active for up to 40 hours after reaching zero-oxygen conditions. Using nonlinear regression tools applied to the available experimental data, we estimated the critical values of the dissolved oxygen levels which characterize the transition from aerobic to anaerobic respiration for each species found tolerating the anoxia. Based on the diffusion-convection transport and the experimentally determined oxygen consumption function, we developed a mathematical model describing the time-dependent changes of the dissolved oxygen concentration which takes into account both aerobic and anaerobic respiratory processes for A. leptodactylus and O. limosus in a virtual burrow filled with water. We further validated our models by comparing numerical simulations with laboratory measurements for different geometries of burrows. Excluding a region at the entrance, the mathematical predictions for a normal day-night cycle of a crayfish inside a (virtual) burrow show that the water-dissolved oxygen inside the burrow reaches anoxia levels within hours. We speculate that the ability of crayfish to cope with oxygen shortages might be a phylogenetic legacy from their ancestors, lobsters, known to encounter low levels of oxygen in deep waters. Most probably, the primary burrowing species lost this ability since the oxygen diffusion is much faster in fossorial burrows, and thus leading to weaker conservation of the specific mechanisms during evolution. These results challenge the current behavioral and physiological knowledge of crayfish, and might drive new perspectives on the ecology, conservation and even evolutionary processes.

Oral Presentations from IAA22

Day 1


Poster Presentations

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