European hub for invaders: Risk assessment of freshwater aquarium fishes exported from the Czech Republic

Abstract

Kalous L., Patoka J., Kopecký O. 2015. European hub for invaders: Risk assessment of freshwater aquarium fi shes exported from the Czech Republic. Acta Ichthyol. Piscat. 45 (3) 239-245.Background. The aquarium fi sh trade is characterized by an enormous number of species. Aquarium fi sh may have an impact on native biota by means of their invasiveness as well as through pathogen transfer. The Czech Republic has become a gateway for aquatic pets into the European Union. The aims of this study were to identify the most common aquarium fi sh species on the wholesale market, to estimate temperature suitability for seasonal (winter and summer) survival in the EU, and also to assess the invasiveness risk of the most common aquarium fi shes with the strongest temperature matching. Materials and methods. Data on aquarium fi sh species, their origin, and availability from producers and traders based in the Czech Republic were collected based on all available sources. The target area was defi ned as all member states of the EU. Estimation of the temperature suitability for each species was done using Climatch 1.0 software. The Freshwater Fish Invasiveness Screening Kit (FISK) was employed for species with temperature suitability within the target area exceeding 10% in the coldest quarter of the year. Results. In total, 1118 fi sh species representing 51 families were identifi ed. Thirty-three species belonging to 13 families were classifi ed as "very common". Three sources of origin were identifi ed: domestic production within the EU, farm production outside the EU, and wild harvests in the region of origin. The major suppliers outside the EU are in south-east Asia. Only one common species originated from wild harvests. FISK scoring divided the 11 species evaluated as having the strongest temperature suitability in the EU (TSEU) into seven species bearing medium risk and four species representing high risk. The family Cyprinidae was the most frequently represented among all evaluated taxa (seven species), but the majority of high-risk fi shes belonged to the family Poeciliidae (three species). The highest score was earned by Carassius auratus (Linnaeus, 1758). Conclusion. The risk potential of aquarium fi shes most traded in the EU seems to be not alarming. Attention should be focused on the possibility of novel pathogen transfer to native aquatic biota as an important aspect of regulating the aquarium fi sh trade.

Procambarus clarkii (Girard, 1852) and crayfish plague as new threats for biodiversity in Indonesia

“…Temperatures during the wettest and driest quarters of the year were used as climatic variables. In accordance with previous studies (Britton, Cucherousset, Davies, Godard, & Copp, ; Kalous, Patoka, & Kopecký, ; Uderbayev et al, ; Vodovsky et al, ), if the values of a climate match between the source area and the climatic station in the target area reached or exceeded 7.0, this was interpreted as no evidence for climatic constraints to the survival of P. clarkii .…”

Cherax quadricarinatus(von Martens) has invaded Indonesian territory west of the Wallace Line: evidences from Java

“…Temperatures during the coldest, warmest, wettest, and driest quarter of the year have been used as variables. In accordance with Kalous et al (2015) we considered a score ≥7.0 as indicating there to be no environmental barrier to survival.…”

Global distribution and climatic match of a highly traded ornamental freshwater fish, the sailfin mollyPoecilia latipinna(Lesueur, 1821)

“…The ecological requirements of freshwater fishes are primarily related to temperature and hydrology (Matthews, 1998). Hence, climatic matching conditions were represented in the current study by the following variables: "Annual mean temperature", "Temperature during the coldest quarter of the year", and "Mean annual rainfall" for the accurate investigation of the potential spread of the evaluated species within the target areas (Costa and Schlupp 2010;Kalous et al, 2015;Kotovska et al, 2016;Patoka et al, 2017), with an Euclidean algorithm. The first two variables were used in order to represent temperature requirements, while the third one was applied as a key component of the hydrological cycle, as well as for its correlation to salinity and photoperiod, tightening up further the climate-matching function.…”

“…This raises some doubt about the role of temperature as the main limiting factor to its invasions. Temperature alone cannot explain the poor representation of the sailfin molly in European waters, especially around the Mediterranean, where summer temperature in some areas would allow at least a seasonal reproduction (Kalous et al, 2015;Perdikaris et al, 2016). Moreover, photoperiod and salinity are critical environmental factors affecting the life and reproductive traits of poeciliids (Baird, 1974;Meffe and Snelson, 1989;.…”