Abstracts
IAA21 Book of Abstracts (PDF)
Meeting Program/Schedule (PDF)
LIST OF MEETING ABSTRACTS
NOTE: You may quickly navigate to a name you are looking for by clicking a letter below (first letter in their lastname).
Oral Presentations
Day: 5, Session: 3, Talk: 4
The Conservation of the White-clawed crayfish, Austropotamobius pallipes in South West England
Jen Nightingale
The white-clawed crayfish, Austropotamobius pallipes (Lereboullet 1858) has suffered severe declines within the South West of England. One of the main threats is due to the invasive signal crayfish Pacifastacus leniusculus (Dana 1852), which was introduced into UK crayfish farms in the mid 1970’s. In response to this decline, The South West Crayfish Partnership (SWCP) was formed in 2008; comprising Bristol Zoological Society, Buglife, Centre for Environment, Fisheries and Aquaculture Science (Cefas), the Environment Agency and Wildlife Trusts. The SWCP implements landscape scale, strategic conservation for A. pallipes, in an attempt to safeguard the future of this species in South West England. The conservation effort has four main strands: (1) Ark sites: safe refuges established throughout the South West, for translocation of a proportion of the most highly threatened whiteclawed crayfish populations; (2) Crayfish captive breeding facility: established at Bristol Zoo, which provides plague-free A. pallipes brood stock for ark site release, reintroductions, research and outreach; (3) Communication strategy: running in tandem with the other two elements, targeting key audiences such as anglers, restaurants, students, school children and zoo visitors; and (4) Invasive crayfish control: Cefas have spent the past two decades developing a variety of techniques to control the invasive crayfish species within the UK. This presentation will cover the key elements of the conservation programme, evaluating its success to date and the impact it has made to preserving white-clawed crayfish within South West England.
Poster Presentations
POSTER 3
White-clawed Crayfish (Austropotamobius pallipes) Endangered Species Sampling Methods: Efficiency and Disruptions in the Balance
Olarte N, García-Arberas L and Alvaro A
The distribution of Austropotamobius pallipes in Biscay (Basque Country) is being increasingly restricted. After crayfish plague and the effects of many further threats, this specie is found in small headwater creeks away from the main streams. The species inhabits in small populations, generally isolated and fluctuating number of individuals. The main characteristic of these river stretches with a little flow is that they do not allow trap sampling methodology and so, other methods based on night viewing are used to get data to calculate population estimates. Two small rivers were sampled for 5 years. In this study, we have compared the values obtained by night viewing from river-bank (CPUEs) with manual searching on one pass (CPUEc). We have also correlated these methods with the estimate population size obtained by Removal method (ABUNDANCE). Both indirect estimates were highly correlated with ABUNDANCE, being stronger CPUEs-ABUNDANCE relationship (p=0.80; R2 =0.64) than CPUEc-ABUNDANCE one (p=0.67; R2 = 0.46). Night viewing is an acceptable strategy for population estimates without a direct interaction with the individuals. This strategy may optimize sampling, as it lets increasing the efficiency in effort and time and minimizing the perturbation generated with catching activity.
POSTER 6
Epifauna on Freshwater Crayfish (Crustacea: Decapoda) in Croatia
Dražina T, Maguire I, Korša A, Špoljar M and Klobučar G
The crustacean exoskeleton is well known substratum for associate species - epibionts. During 2014 and 2015, we have studied epifauna on six different freshwater crayfish species collected from continental and mediterranean regions of Croatia (Europe). Four of them are autochthonous (Astacus astacus, Astacus leptodactylus, Austropotamobius pallipes, Austropotamobius torrentium) and two allochthonous invasive species (Pacifastacus leniusculus and Procambarus fallax f. virginalis). The epibiont samples were collected from the exoskeleton surface and from the crayfish gill cavity. The aims of this research were: (i) to analyse epifaunal assemblage on different freshwater crayfish and (ii) to compare epifauna among different crayfish populations, especially between autochthonous and allochthonous species. A total of 44 different epifaunal taxa were recorded. The most abundant group was Ciliophora, with Vorticella campanula and Epistylis sp. as the most frequent taxa. Rotifera was the most diverse group and 16 different taxa were identified. Four rotifer species (Lepadella astacicola, L. branchiola, L. parasitica and Dicranophorus hauerianus) were determinated as specific inhabitants of certain crayfish species and these rotifers were found exclusively on autochthonous species. Branchiobdellidans were constant crayfish epibionts, and for the first time the North American species Xirogiton victoriensis has been recorded in Croatia. Representatives from Catenulida, Gastrotricha, Nematoda, Bivalvia, Hirudinea, Tardigrada, Crustacea, Hydrachnidia and Chironomidae were also recorded as epibionts on freshwater crayfish. Results of this study suggested the separation of epifaunal assemblage between autochthonous and allochthonous crayfish, as well as the separation of epifauna among autochthonous species. Our results indicate highly diverse, complex and specific epifaunal assemblage on different crayfish populations. Thus, multiple relationships between crayfish host and epibionts will be the topic of further studies.
POSTER 9
Metabolic Rate of Cambarellus montezumae (Crustacea: Cambaridae): Effects of Size and Seasonal Changes
Latournerié-Cervera JR, García-Padilla GM, and Estrada-Ortega AR
The measurement of metabolic rate is a key element of a species energy balance. The evaluation of respiratory metabolism in natural conditions, allows us to know the energy requirement of the animal for different processes including growth, activity, reproduction, among others. The objective of this study was to know the element (R) of the energy budget equation: C = P+R+F+U (IBP, 1968) in Cambarellus montezumae, during hot rainy season (May – August) and transitional months (September – October) in the area of study. Recently collected samples of crayfish (n=15) representing small, medium and large sizes of both sexes were employed in respirometry experiments, using a closed respirometer. The temperature and water quality were similar to the conditions of the sampling site. Two measurement periods were used: (noon and evening). Average routine metabolic rate was used for comparisons (QO2: mg O2/g. dry weight/h) and was converted to cal/g.dw/day using the Qox=3.31 cal/mgO2 (Brafield & Solomon, 1972). Comparisons for size and month were made by ANOVA factorial (3 X 6) and Tukey test post hoc (p<0.05). Significant differences were obtained by month and size. QO2 was similar between the months of the rainy season, with a temperature average range of (22.3 ± 1.6°C) and had a significant decrease (p<0.05) in October. Relationships of QO2 – WW were calculated for all months using a potential model. We discuss results in relation to energy requirements of the species for growth and reproduction and its potential use for intensive management.
POSTER 15
Reproductive Cycle of the Marble Crayfish from an Established Population in Croatia
Cvitanić M, Hudina S and Maguire I
The marble crayfish (Procambarus fallax f. virginalis) is a relatively new non-indigenous crayfish species that has established populations in Europe. Until today, it is the only known decapod species with parthenogenetic reproduction. Established population of marble crayfish was recently discovered in a gravel pit in Northwest Croatia. Apart from parthenogenetic reproduction, the invasion success of this species stems from its early maturation, and higher fecundity compared to other crayfish species. Therefore, the aim of this study was to examine the year cycle of the marble crayfish in Croatia, and its potential (number of ovarian eggs) and realized fecundity (number of pleopodal eggs and juveniles). Our results show that all 140 examined individuals were reproductively active during the whole sampling period. Peaks of reproduction activity were recorded from September to November, when both individuals with pleopodal eggs or juveniles as well as individuals with ripe ovarian eggs were recorded. The smallest reproductively active female was 40.81 mm TL, while reproductive output increased with size (TL). The average number of ovarian eggs was 297. The average number of pleopodal eggs was 15% lower than the number of ovarian eggs, while number of juveniles attached to pleopods was reduced by 50% from ovarian egg count. This represents a lower brood loss compared to other crayfish species. Due to almost constant reproduction, early maturation and relatively high potential and realized fecundity in an established population in Croatia, the marble crayfish represents a major threat to the surrounding waterbodies and their native crayfish fauna.
POSTER 16
Assembly and Annotation of the Marbled Crayfish Genome
Gutekunst J, Falckenhayn C, Gatzmann F, Raddatz G and Lyko F
Marbled crayfish (Procambarus virginalis) are the only freshwater crayfish known to reproduce by cloning (apomictic parthenogenesis). Notably, among genetically identical offspring raised in the same environment distinct phenotypic differences can be observed. These characteristics render the marbled crayfish an interesting laboratory model. A prerequisite for introducing this triploid arthropod as a new model organism and focus of this thesis is the identification of its complete genome sequence. We experimentally determined the genome size at approximately 3.5 Gbp by k-mer analysis and flow cytometry. High coverage sequencing data (~70X) of one individual female was used for a first de novo draft assembly with a length weighted median scaffold size (N50) of 40 kb. Assessing genome completeness using the benchmarking software BUSCO we were able to identify 56% complete and 21% fragmented (out of 2675) conserved single-copy arthropod orthologs. Single nucleotide variations (SNP) analyses of four additionally sequenced individuals from different strains confirmed clonal reproduction and enabled us to describe genomic characteristics such as triploidity and common genotypes. By interspecies comparisons to the closest relative, the sexually reproducing Procambarus fallax, and preliminary automatic genome annotation of about 15,000 protein coding transcripts we found potential alterations in meiosis related genes. These findings provide new insights into mechanisms of parthenogenesis. Genomic data and manual curation services are, after registration, publicly accessible at our Marmorkrebs webserver (http://marmorkrebs.dkfz.de).
POSTER 19
Invader showdown: interference competition between Orconectes immunis and Pacifastacus leniusculus
Wendler F and Chucholl C
Alien crayfish are among the most damaging invaders of European inland waters and changes in the crayfish fauna should be monitored prudently. Here, we investigated for the first time direct aggressive interactions and competition for shelter between alien calico crayfish, Orconectes immunis, and signal crayfish, Pacifastacus leniusculus, which are highly invasive in Central Europe. Specifically, we monitored bouts of interspecific 1:1 combinations in laboratory experiments and offered limited shelters in a similar setting. In size- and sex-matched combinations, O. immunis won significantly more interactions than P. leniusculus; however, O. immunis females were inferior to size-matched P. leniusculus males. Similarly, P. leniusculus males were dominant over 4 mm smaller O. immunis males in chelae size-matched bouts. Both species showed a similar affinity to the provided shelter, but O. immunis was dominant in the shelter competition experiments in both sexes. The dominance of O. immunis males in size-matched combinations may be related to their greater 'resource holding potential' due to larger chelae size than P. leniusculus males. Orconectes immunis females, however, featured similar sized chelae than size-matched P. leniusculus females, and their dominance can best be explained by higher inherent aggression of O. immunis. Based on these results, O. immunis can be expected to outcompete similar sized P. leniusculus. However, since the latter invader grows considerably larger than O. immunis, and gained dominance at a size advantage of 4 mm, outcomes of interactions in the field may be much more complex, presumably also due to contrasting life-history strategies.
POSTER 24
Effect of Pharmaceuticals on Crayfish
Shaliutina O and Bláha M
The release of human pharmaceuticals and personal care products into aquatic ecosystems continues to be a serious environmental problem. There is a staggering list of pharmaceuticals that have been detected in surface water, groundwater and tap water. These compounds typically modify the physiology or behavior, of the intended target system, without lethal effect. The wide range of entry points into freshwater systems reaffirms that animals living within those habitats face continuous exposure to pharmaceuticals, even if only at low doses. Crayfish are a crucial invertebrate in freshwater ecosystems. They are omnivorous, and occupy a key position in the trophic web as both predator and prey. With the importance of crayfish to their ecosystems, the introduction of pollutants such as pharmaceuticals, could have negative effects to crayfish populations. For example, pharmaceuticals can cause a mediating aggressive behavior. It has been demonstrated that crayfish injected with serotonin (antidepressant) fights lasted considerably longer. Also, the lasting impact of pharmaceuticals leads to immune system function decline, which greatly increases the mortality rate. Moreover, they can slow down synthesize and release of hormones from the X-organ sinus complex, and thus influence molting, gonad development, water balance, blood glucose, etc. However, despite all data the impact of pharmaceuticals on particular developmental stages, mortality, growth rate and postembryonic development of crayfish had not yet been fully explored. Therefore, we provide an overview about the known effects of pharmaceuticals on crayfish and demonstrate that these effects could be quite multifaceted.
POSTER 26
The River Barle Signal Crayfish Project: Assessing the Potential of Male Sterilisation as a Signal Crayfish Control Technique
Green N, Stebbing P, Bentley M, Andreou D and Lane M-R
This poster will present the methods and results to date of the River Barle Signal Crayfish Project which aims to test the effectiveness of a Sterile Male Release Technique in controlling signal crayfish on a 1.5km stretch of the River Barle Site of Special Scientific Interest, south west England, UK, between 2015 and 2017. The methodology consists of the intensive trapping and removal of all crayfish apart from dominant males (above 40mm carapace length) which are manually sterilised (vasectomised) and returned to the river. Two types of trap are used, standard funnel traps and novel artificial refuge traps which have proved far more effective and less biased than funnel traps. Detailed sampling of crayfish density, fish and invertebrates is taking place in the study area and a control site throughout and beyond the trial period. Laboratory experiments are investigating various aspects of mating behaviour including mate choice and female monoandry. The results feed into a PhD study guided by Bournemouth University, the Centre for Environment, Fisheries Aquaculture Science (CEFAS) and the Environment Agency. Trapping is being carried out by a group of 40 volunteers, many of them local people with an interest in the river. If the method is successful, the project aims to pass ownership on to local stakeholders so it can be continued over the long term without relying on external funding - a trial of this approach is also underway.
POSTER 28
Management of the Native White-clawed Crayfish, Austropotamobius pallipes, in the Province of Girona
Montserrat J, Macias M and Torres F
The native white-clawed crayfish (Austropotamobius pallipes) was a species commonly found in most watercourses in the basins of the rivers Fluvià, Ter and Muga until the end of the 1970s, when the crayfish plague Aphanomyces astaci arrived, a water mould that led to the disappearance of almost all the populations in these river basins. The white-clawed crayfish populations are currently found in second-order or larger seasonal rivers and fast-flowing streams where, due to some kind of natural barrier (drought in the lower reaches of the watercourse, cliffs, etc.), the fungus was unable to grow. Moreover, during the 1990s, the red swamp crayfish (Procambarus clarkii) population expanded rapidly in the basin and the situation became far worse, since the North American species is both a carrier of the crayfish plague and resistant to this fungal disease. Later, the signal crayfish (Pacifastacus leniusculus) arrived in the Ter River and the spinycheek crayfish (Orconectes limosus) arrived in the Muga River Basin, both species being carriers of the pathogen Aphanomyces astaci. This situation means relict populations of the white-clawed crayfish cannot expand and are forced to survive in the most inaccessible seasonal rivers and fast-flowing streams, facing the danger of a new outbreak of crayfish plague.
Oral Presentations from IAA21
No PowerPoint presentations are currently available for this symbosium.
Poster Presentations
No poster PDFs are currently available for this symbosium.
General Assembly
No General Assembly PowerPoint presentation is currently available for this symbosium.
Meeting Photo Gallery
There are currently no photos from this meeting to display.
