Yonvitner and colleagues, 2020

Yonvitner Y, Patoka J, Yuliana E, Bohatá L, Tricarico E, Karella T, Kouba A, Reynolds JD. 2020. Enigmatic hotspot of crayfish diversity at risk: Invasive potential of non-indigenous crayfish if introduced to New Guinea. Aquatic Conservation: Marine and Freshwater Ecosystems 30(2): 219-224. https://onlinelibrary.wiley.com/doi/abs/10.1002/aqc.3276

Abstract

1. The large island of New Guinea has a rich indigenous astacofauna represented by numerous parastacids from the genus Cherax. The western half of the island is part of Indonesian territory.
2. Indonesia is known to be the main exporter of ornamental crayfish globally, and certain New Guinean species are exploited as ornamentals within the international pet trade. Moreover, one non‐indigenous species has been previously recorded being cultured in Java, Indonesia. This species, the North American Procambarus clarkii, is a vector of crayfish plague, the disease that is lethal to most parastacids. This population has already tested positive for the disease.
3. As the transport of non‐indigenous crayfish within the Indonesian territory is not restricted, their introduction to New Guinea can be expected. The Indonesian market was therefore surveyed for ornamental crayfish and their environmental suitability evaluated, as represented by temperature during the drought and rainy seasons in New Guinea.
4. Four North American and one Australian species were found advertised for sale. One of them, P. clarkii, was assessed as the most damaging species, followed by other North American species. A total ban on the culture and transport of the highest risk crayfish species in Indonesia and Papua New Guinea is recommended.

Keywords: Cambaridae • Cherax • climate matching • EICAT • Indonesia • MaxEnt • Parastacidae • pet trade • risk assessment

Hossain and colleagues, 2020

Hossain MS, Guo W, Martens A, Adámek Z, Kouba A, Buřič M. 2020. Potential of marbled crayfish Procambarus virginalis to supplant invasive Faxonius immunis. Aquatic Ecology: 54: 45-56. https://doi.org/10.1007/s10452-019-09725-0

Abstract

Biological invasions are a growing threat to global biodiversity due to negative impacts on native biota and ecosystem functioning. Research has expanded from investigating native and alien species interactions to examining relationships among alien species. Invasive crayfish may have similar life histories, niche preferences, and adaptation strategies, but their mutual interactions are little understood. This study aimed to quantify interaction patterns of size-matched calico crayfish Faxonius immunis, established in the Rhine River catchment, and the parthenogenetic marbled crayfish Procambarus virginalis, currently spreading throughout Europe. During agonistic interactions in the absence of shelter, marbled crayfish won a significant majority of fights against calico crayfish, but in the presence of shelter there was no significant difference. When sex of calico crayfish was considered in the analysis without shelter, marbled crayfish won a significantly higher number of fights with female calico crayfish. In the absence of shelter, marbled crayfish dominated calico crayfish females in 83.3% and males in 60% of pairs. With available shelter, the dominance of marbled crayfish was 100% and 54.5% over female and male calico crayfish, respectively. The results suggested that sex and resource availability influence agonistic behaviour in the studied crayfish. Marbled crayfish are confirmed to be competitive against the calico crayfish, which has been shown to be dominant over another serious invader in the Rhine River catchment, the spiny-cheek crayfish Faxonius limosus. In natural sympatric populations, the situation may be affected by factors such as size, reproductive variables, water temperature, and predation pressure.

Keywords: biological invasion • calico crayfish • competition • dominance • interaction • marbled crayfish

Tönges and colleagues, 2020

Tönges S, Masagounder K, Gutekunst J, Lohbeck J, Miller AK, Böhl F, Lyko F. 2020. Physiological properties and tailored feeds to support aquaculture of marbled crayfish in closed systems. bioRxiv: 2020.2002.2025.964114. https://doi.org/10.1101/2020.02.25.964114 (Unreviewed preprint)

Abstract

The marbled crayfish (Procambarus virginalis) is a new freshwater crayfish species, which reproduces by apomictic parthenogenesis, resulting in a monoclonal, all-female population. The animals have become a popular source for nutritional protein in Madagacar and are increasingly being considered for commercial aquaculture. However, their potential has remained unclear and there are also significant ecological concerns about their anthropogenic distribution. We show here that the size and weight of marbled crayfish is comparable to commonly farmed freshwater crayfish. Furthermore, purification of chitin from marbled crayfish shells revealed a high chitin content, which can be utilized for the synthesis of chitosan and other bioplastics. To allow the further evaluation of the animals in closed aquaculture systems, we used a factorial modeling approach and formulated tailored feeds that were matched to the marbled crayfish amino acid profile. These feeds showed superior performance in a feed trial, with a noticeable feed conversion rate of 1.4. In conclusion, our study provides important data for a balanced assessment of marbled crayfish as a new species for sustainable aquaculture and a feed that allows their culture in closed systems.

Keywords: None provided.

PhD position with Marmorkrebs

A doctoral position to study “Marbled crayfish as a model organism” is available! The position is in Czechia with Antonín Kouba. More information about the position are here.

Canadian province of Ontario asks for input on Marmorkrebs

Marmorkrebs may be added to Ontario’s invasive species list.

Several news outlets are reporting that the province’s Ministry of Natural Resources and Forestry is seeking public feedback concerning thirteen new species that might be added to the list.

Besides Marmorkrebs, the Louisiana red swamp crayfish (Procambarus clarkii) is another contender for regulation. If either was added, they would join one crayfish that is already regulated in Ontario, the Australian yabby (Cherax destructor).
 
A link to the Ontario government’s feedback page can be found here. The ministry says it will keep consultation open until 30 March 2020.

I highly recommend any crayfish biologists, particularly those with expertise in Marmorkrebs, complete the feedback form.

External links

Ontario taking action against invasive species
Province asking for feedback on invasive species
MNRF wants your opinion on 13 invasive species from wild pigs to red swamp crayfish
Province seeks input on 13 invasive species

Velisek and colleagues, 2020

Velisek J, Stara A, Kubec J, Zuskova E, Buric M, Kouba A. 2020. Effects of metazachlor and its major metabolite metazachlor OA on early life stages of marbled crayfish. Scientific Reports 10(1): 875. https://doi.org/10.1038/s41598-020-57740-1

Abstract

The effects of the herbicide metazachlor and its major metabolite metazachlor OA at two concentrations, including environmentally relevant concentrations of metazachlor (0.0115 µmol/l and 0.0790 µmol/l) and metazachlor OA (0.0117 µmol/l and 0.0805 µmol/l), respectively, were evaluated on early ontogeny, growth, behaviour, oxidative stress, antioxidant enzyme levels, histology, and mortality of marbled crayfish Procambarus virginalis. Both tested concentrations of metazachlor and metazachlor OA were associated with significantly lower growth and delayed ontogenetic development compared to controls. Exposure of metazachlor at 0.0115 µmol/l and metazachlor OA at 0.0117 µmol/l and 0.0805 µmol/l resulted in significantly lower activity of total superoxide dismutase (SOD), catalase (CAT), glutathione s-transferase (GST), glutathione reductase (GR), and reduced glutathione (GSH) compared with control and resulted in gill anomalies ranging from wall thinning to focal disintegration of branchial structure. Metazachlor at the environmentally relevant concentration of 0.0790 µmol/l was associated with significant alterations of crayfish distance moved and walking speed. The potential risk associated with metazachlor use in agriculture related to effects on non-target aquatic organisms.

Keywords: None provided.

Vogt, 2020

Vogt G. 2020. Biology, ecology, evolution, systematics and utilization of the parthenogenetic marbled crayfish, Procambarus virginalis. In: Ribeiro FB (ed.), Crayfish: Evolution, Habitat and Conservation Strategies, pp. 137-227. Nova Publishers: Hauppauge. https://novapublishers.com/shop/crayfish-evolution-habitat-and-conservation-strategies/

Abstract

The marbled crayfish, Procambarus virginalis, is the only obligately parthenogenetic species of the 15,000 decapod crustaceans. This chapter describes its detection history, biology, taxonomy, geographical distribution, ecology, evolution and utilization. The marbled crayfish was detected in 1995 in the German aquarium trade. Morphological and genetic evidence suggests that it has arisen by autotriploidy from slough crayfish, Procambarus fallax, which is native to Florida and southern Georgia. Since marbled crayfish was neither described in the extensive biogeographical literature on crayfishs of this region nor found in respective museum collections it is thought to have originated in evolutionarily recent times, perhaps in captivity. Genetic investigations revealed that marbled crayfish is of single origin and monoclonal. Comparison of morphology, life history, genetics, reproduction, behavior, ecology and biogeography between marbled crayfish and its parent species and application of the Evolutionary Genetic Species Concept for Asexuals suggests treating marbled crayfish as a separate species rather than keeping it as a parthenogenetic lineage within Procambarus fallax. Beginning in the late 1990s, marbled crayfish was spread from Germany across the world. Releases have led to the establishment of wild populations in 16 countries on three continents. In Madagascar, marbled crayfish has already invaded a considerable proportion of the country. Behavioral and ecological data suggest that marbled crayfish can compete with other crayfish species, even with much bigger ones. Despite of genetic uniformity, marbled crayfish have adapted to a wide range of habitats in tropical to cold-temperate biomes. This was apparently possible by their capability to produce different phenotypes from the same genome by epigenetic mechanisms. Because of genetic identity, high fecundity, easy rearing, the availability of a draft genome and further advantages, the marbled crayfish is increasingly being used as a laboratory model for research including development, neurobiology, behavior, reproduction, toxicology, stem cell biology, genetics, epigenetics, and invasion biology. In Madagascar, wild marbled crayfish stocks are exploited as a food commodity.

Keywords: biogeography • competition • ecology • evolution • invasion • marbled crayfish • parthenogenesis • research model • systematics • exploitation