Electronic Supplementary Material

Risk assessment of the crayfish pet trade based on data from the Czech Republic

Jiří Patoka*, Lukáš Kalous, Oldřich Kopecký

Faculty of Agrobiology, Food and Natural Resources, Department of Zoology and Fisheries, Czech University of Life Sciences Prague, Kamýcká 129, CZ-165 21 Praha 6 – Suchdol, Czech Republic

*E-mail: , tel: +420724810365

Materials and Methods

Data collection

Discussions with five wholesalers who are the leading importers of live crayfish in the Czech Republic were conducted during the period 9–30 September 2012. Records were made of written responses, including additional oral explanations that helped to clarify certain queries or provided supplementary information on the crayfish trade. To ensure correct identification of species handled by those wholesalers interviewed, crayfish were photographed and determination keys (Füreder and Machino 2002) as well as new species descriptions (Lukhaup and Pekny 2006, 2008; Lukhaup and Herbert 2008) were used.

According to the laws and regulations in force in the Czech Republic, the import of live animals and their products is registered by the Czech Customs Administration.

Each species’ availability for wholesale was assessed in accordance with Chucholl (2013) using the following criteria: i) species available only for a short period and in low quantities were rated “very rare”; ii) species available occasionally in low quantity were rated “rare”; iii) species available frequently in low numbers were rated “common”; and iv) species always available in high numbers were rated “very common”.

Risk assessment

The risk related to the crayfish trade in the Czech Republic was evaluated with the help of the Freshwater Invertebrate Invasiveness Scoring Kit produced by the UK Centre for Environment, Fisheries & Aquaculture Science (FI-ISK, v.1.19). FI-ISK was especially calibrated for freshwater invertebrates (Tricarico et al. 2010). This tool had previously been used for risk scoring of crayfish species in Germany (Chucholl 2013) and Greece, respectively (Papavlasopoulou et al. 2014). FI-ISK is able to accurately distinguish potentially invasive and non-invasive NICS by invasiveness score and subsequently by classification of species into the following three risk categories: i) low (score <1), ii) medium (score ≥1 but <16), and iii) high (score ≥16) (35). Climate data for the native and risk area (including 16 stations for the Czech Republic) of evaluated crayfish species were obtained using the Climatch tool (v.1.0; Invasive Animals Cooperative Research Centre, Bureau of Rural Sciences, 2008). Zoogeographical, biological and ecological data for the species were obtained from previous studies (Hobbs 1971, 1974; Huner 1984; Holthuis 1986; Hendrix and Loftus 2000; Scholtz 2003; Beatty et al. 2005; Lukhaup and Pekny 2006; Petrusek et al. 2006; Souty-Grosset et al. 2006; Lukhaup and Pekny 2008; Buřič et al. 2011). Characteristics such as indigenous range, fecundity and minimum age at maturity of the Cherax spp. for which such data are not available were assumed to correspond with those of Cherax holthuisi, as recommended by Chucholl (2013).

Statistical analysis

We used a generalized linear model (GLZ in StatSoft) with availability in the wholesale trade as the categorical variable and FI-ISK score as the numeric variable; their significance was tested using Type III likelihood ratio test. Origin of particular crayfish species was used as binary dependent variable (North America vs. rest of the world). Statistical significance was determined at the level α = 0.05. The test was computed using Statistica 12.0 (Statsoft Inc., 2012).

References

Beatty S, Morgan D, Gill H (2005) Role of life history strategy in the colonisation of Western Australian aquatic systems by the introduced crayfish Cherax destructor Clark, 1936. Hydrobiologia 549:219–237

Buřič M, Hulák M, Kouba A, Petrusek A, Kozák P (2011) A successful crayfish invader is capable of facultative parthenogenesis: A novel reproductive mode in decapod crustaceans. PLoS ONE 6:e20281

Chucholl C (2013) Invaders for sale: trade and determinants of introduction of ornamental freshwater crayfish. Biol Invasions 15:125-141

Füreder L, Machino Y (2002) A revised determination key of freshwater crayfish in Europe. Ber Naturwiss-Med Ver Innsbruck 89:169-178

Hendrix AN, Loftus WF (2000) Distribution and relative abundance of the crayfishes Procambarus alleni (Faxon) and P. fallax (Hagen) in Southern Florida. Wetlands 20:194-199

Hobbs HH (1971) A new troglobitic crayfish from Florida. Q J Florida Acad Sci 21:71-91

Hobbs HH (1974) A checklist of the North and Middle American crayfishes (Decapoda: Astacidae and Cambaridae). Smithson Contrib Zool 166:1-161

Lukhaup C, Herbert B (2008) A new species of crayfish (Crustacea: Decapoda: Parastacidae) from the Fly River Drainage, Western Province, Papua New Guinea. Mem Queensl Mus 52:213–219

Lukhaup C, Pekny R (2006) Cherax (Cherax) holthuisi, a new species of crayfish (Crustacea: Decapoda: Parastacidae) from the centre of the Vogelkop Peninsula in Irian Jaya (West New Guinea), Indonesia. Zool Med Leiden 80-81:101-107

Lukhaup C, Pekny R (2008) Cherax (Astaconephrops) boesemani, a new species of crayfish (Crustacea: Decapoda: Parastacidae) from the centre of the Vogelkop Peninsula in Irian Jaya (West New Guinea), Indonesia. Zool Med Leiden 82:1-10

Papavlasopoulou I, Perdikaris C, Vardakas L, Paschos I (2014) Enemy at the gates: introduction potential of non-indigenous freshwater crayfish in Greece via the aquarium trade. Cent Eur J Biol 9:1-8

Petrusek A, Filipová L, Ďuriš Z, Horká I, Kozák P, Policar T, Štambergová M, Kučera Z (2006) Distribution of the invasive spiny-cheek crayfish (Orconectes limosus) in the Czech Republic. Past and Present. B Fr Peche Piscic 380-381:903-918

Scholtz G, Braband A, Tolley L, Reimann A, Mittmann B, Lukhaup C, Steuerwald F, Vogt G (2003) Parthenogenesis in an outsider crayfish. Nature 421:806

Souty-Grosset C, Holdich DM, Noel P, Reynolds JC, Hafner P (2006) Atlas of Crayfish in Europe. Museum National d´Histoire Naturelle, Paris (Patrimoines naturels, 64)

Tricarico E, Vilizzi L, Gherardi F, Copp GH (2010) Calibration of FI-ISK, an invasiveness screening tool for nonnative freshwater invertebrates. Risk Anal 30:285-292