30 November 2016

Ninth International Crustacean Congress announcement and call for symposia

The 9th International Crustacean Congress (ICC IX) will be held in Washington, DC from 22-25 May 2018, at the Smithsonian Institution and the Renaissance Hotel. This marks the first time this meeting has been in the USA and at the venerable Smithsonian Institution.

The ICC IX Organizing Committee is requesting ideas and leaders for symposia for this important meeting.

Symposia can be half days or full days and can be on any broad topic associated with crustacean biology or related research whether basic or applied. Broad ideas that would include Crustacea combined with other taxa, are welcome. Possible areas for symposia development include genomics/transcriptomics, reproduction, biodiversity, palaeontology, microbiomes, parasites and evolution, invasion biology, aquaculture, fisheries, and so on.

Please communicate symposium ideas to Chris Tudge at ctudge@american.edu.

More information to follow, including important dates and the ICC IX website.

Picture: Famed carcinologist Mary Jane Rathbun in the Smithsonian. Picture from here.

05 November 2016

Takahashi and Nagayama, 2016

Takahashi K, Nagayama T. 2016. Shelter preference in the Marmorkrebs (marbled crayfish). Behaviour 153(15): 1913-1930. http://dx.doi.org/10.1163/1568539X-00003399

For many animals, shelters are valuable source to hide from predators. To know acquisition of adequate shelter is important to understand social interactions of animals. Preferences for types of shelter used by the Marmorkrebs (marbled crayfish) were analysed behaviourally. Individual crayfish were presented with a choice between two PVC pipes with four different internal diameters (XL, L, M and S). The time spent in each shelter and the number of times crayfish entered each shelter were measured. Preference ranks of crayfish were XL = L = or > M > S. Our experiments strongly suggested that crayfish chose shelters based first on the diameter of the entrance, and then based on the length of the shelter. Crayfish recognised adequate shelters by visual cues under light conditions and utilised tactile cues from their antennae under dark conditions.

Keywords: recognition • visual cue • crayfish • shelter choice • thigmotactic cue

01 November 2016

Vogt, 2016c

Vogt G. 2016. Direct development and posthatching brood care as key features of the evolution of freshwater Decapoda and challenges for conservation. In: Kawai, T. and Cumberlidge, N. (eds.), A Global Overview of the Conservation of Freshwater Decapod Crustaceans, pp. 169-198. Springer International Publishing: Cham. http://dx.doi.org/10.1007/978-3-319-42527-6_6


Direct development and posthatching brood care are among the key evolutionary adaptations of decapod crustaceans to life in fresh water. Direct development is obligatory in aeglid anomurans, primary freshwater crabs, and freshwater crayfish. It also occurs in some species of secondary freshwater crabs and freshwater shrimps. Posthatching brood care is the rule in aeglids, primary freshwater crabs, and crayfish, infrequent in secondary freshwater crabs, and rare in freshwater shrimps. Extended brood care is most intense in crayfish where it includes the attachment of hatchlings by a safety line, and specific behaviours of the mother and her offspring. Direct development and posthatching brood care are associated with reduced dispersal and reduced gene flow among populations, which may explain the high degree of endemism and speciation in freshwater decapods. Due to the reduced dispersal and recolonization abilities aeglids, primary freshwater crabs, and crayfish that live in stressed freshwater habitats may face a higher threat of extinction than do species of amphidromous shrimps and crabs that can undergo long-distance migrations.

Keywords: freshwater Decapoda • direct development • posthatching brood care • evolutionary adaptation • speciation • endemism • conservation

Kawai and Crandall, 2016

Kawai T, Crandall KA. 2016. Global diversity and conservation of freshwater crayfish (Crustacea: Decapoda: Astacoidea). In: Kawai T, Cumberlidge N (eds.), A Global Overview of the Conservation of Freshwater Decapod Crustaceans, pp. 65-114. Springer International Publishing: Cham. http://dx.doi.org/10.1007/978-3-319-42527-6_3


The number of species in the three families of freshwater crayfish worldwide (Astacidae, Cambaridae, and Parastacidae) are updated by region. These are: Astacidae, western North America (5 species) and Europe (5 species), Cambaridae, eastern North America and Mexico (423 species) and Asia (6 species), and Parastacidae, Oceania (153 species), South America (12 species), and Madagascar (7 species). The conservation status of 611 species of crayfish worldwide is discussed, based on global assessments from the IUCN (International Union for Conservation of Nature) Red List protocols as well as regional assessments on governmental endangered species lists. The current threats to endangered species of crayfish include habitat destruction, water diversion, pollution, and threats from exotic species of crayfish (such as Pacifastacus leniusculus, Procambarus clarkii and Cherax) that have been introduced to other parts of the world where they are having an increasing impact. New threats posed by the parthenogenetic marbled crayfish Procambarus fallax f. virginalis to freshwater ecosystems in Europe and Madagascar are also discussed.

Keywords: alien crayfish • conservation • species diversity • IUCN Red List