Deidun and colleagues, 2018

Deidun A, Sciberras A, Formosa J, Zava B, Insacco G, Corsini-Foka M, Crandall KA. 2018. Invasion by non-indigenous freshwater decapods of Malta and Sicily, central Mediterranean Sea. Journal of Crustacean Biology 38(6): 748–753. http://dx.doi.org/10.1093/jcbiol/ruy076

Abstract

Invasive species can cause significant changes in local and regional ecologies, especially in freshwater ecosystems. It is thus important to monitor and document the spread of non-indigenous species to such habitats as such information can be critical to preserving habitats and species. We document the spread of the red swamp crayfish Procambarus clarkii (Girard, 1852) (Cambaridae), a highly invasive non-indigenous species, in Malta and south Sicily. We also document the first records of other non-indigenous decapods important in the pet trade or in aquaculture, Procambarus virginalis Lyko, 2017 (Cambaridae), Pontastacus leptodactylus (Eschscholtz, 1823) (Astacidae), Cherax quadricarinatus von Martens, 1868 (Parastacidae), Pacifastacus leniusculus (Dana, 1852) (Astacidae), and Atyopsis moluccensis (De Haan, 1849 (Atyidae) from freshwater localities in the Maltese Archipelago and Cherax destructor Clark, 1936 (Parastacidae) from southeastern Sicily. The study provides recommendations on the adoption of control measures by the competent national authorities with respect to these non-indigenous species.

Keywords: None provided.

Vogt and colleagues, 2018

Vogt G, Lukhaup C, Williams BW, Pfeiffer M, Dorn NJ, Schulz R, Schrimpf A. 2018. Morphological characterization and genotyping of the marbled crayfish and new evidence on its origin. Zootaxa 4524(3): 329–350. https://doi.org/10.11646/zootaxa.4524.3.3

Abstract

The obligately parthenogenetic marbled crayfish, Procambarus virginalis, is the first formally described asexual species of the Crustacea Decapoda. It is a triploid descendant of the sexually reproducing slough crayfish, Procambarus fallax. Here we describe the morphology of cultured and wild marbled crayfish of wide size ranges in detail and photodocument all taxonomically relevant characters. Some morphological traits and coloration showed considerable variation within populations despite the monoclonal nature of marbled crayfish. There were also significant differences between wild and laboratory populations with respect to body proportions, coloration and spination. Comparison with Procambarus fallax revealed no qualitative morphological characters that unambiguously identify the marbled crayfish. Analysis of the mitochondrial cytochrome c oxidase subunit I gene (COI) and nuclear microsatellites of marbled crayfish and Procambarus fallax from different sources indicated that the tri-allelic microsatellite PclG-02 is better suitable than COI to identify the marbled crayfish. A respective identification key is provided. The COI and  microsatellites of Procambarus fallax from different areas of Florida and southern Georgia suggest that the parents of the first marbled crayfish may have come from northern Union County, northern Florida.

Keywords: morphology, genotyping, evolution, marbled crayfish, Procambarus fallax

(Note: An open access preprint of this work is available. Vogt G, Dorn NJ, Pfeiffer M, Lukhaup C, Williams BW, Schulz R, Schrimpf A. 2018. In-depth investigation of the species problem and taxonomic status of marbled crayfish, the first asexual decapod crustacean. BioRxiv: 26 June 2018. https://doi.org/10.1101/356170)

Marmorkrebs in silhouette

In case you need a representation of a marbled crayfish to pop into one of your figures, or any other kind of organism, try Phylopic. While I was tooling around there, I found this image of Marmorkrebs by Kamil S. Jaron:

Presumably, a couple of legs are being held under the body. And I wouldn’t trust this page for taxonomic information, as the authority given for Marmorkrebs is incorrect. Not sure how easy it is to fix that.

Update, 9 November 2018: It’s fixed on both counts! Woohoo!

New link for new image is here.

External links

Phylopic