The threats posed by the pet trade in alien terrestrial invertebrates in South Africa

Abstract

The pet trade has been a major pathway for the introduction of vertebrate invaders, but little is known about its role in invertebrate invasions. Here we assess the trade in terrestrial invertebrates (excluding spiders) in South Africa and the potential of this trade to result in biological invasions and impacts. Pet stores, websites, and expositions were visited, and a list of the taxa traded was compiled. DNA barcoding was used to determine if the species were correctly identified in the trade. Information on invasion history and impact elsewhere was used to assess the potential for species to become invasive and have impact in South Africa. We found 53 alien terrestrial invertebrate taxa that were traded, although only 36 of these matched a valid species name. Of 11 species tested using DNA barcoding nine were correctly identified. Species accumulation curves were produced, but did not reach an asymptote, suggesting there are many species in the trade that were not recorded. The most common species were used as food for pets, rather than as pets themselves. None of the species were reported to be invasive elsewhere, and few had records of causing negative impacts (the exception being moderate impacts to human health caused by venomous scorpions). Therefore, there is little evidence that the invertebrates traded pose a significant threat to South Africa. However, given uncertainties in which taxa are traded and the lack of data on invasiveness and impact, there might be a significant invasion debt. We recommend continued monitoring and engagement with the industry.

Assessing the potential impacts of non-native small mammals in the South African pet trade

“…It is also possible that most of the impacts reported elsewhere for these non-native mammals have already taken place in South Africa but are not yet documented. The results for the present study were different when compared with a study on non-native invertebrate pets in South Africa which found that popular species had minimal impacts (Nelufule et al 2020). This difference may be explained by the fact that invertebrates are generally not well studied when compared with mammal species (Nentwig et al 2010;Kumschick et al 2015;Hagen and Kumschick 2019;Nelufule et al 2020).…”

“…The results for the present study were different when compared with a study on non-native invertebrate pets in South Africa which found that popular species had minimal impacts (Nelufule et al 2020). This difference may be explained by the fact that invertebrates are generally not well studied when compared with mammal species (Nentwig et al 2010;Kumschick et al 2015;Hagen and Kumschick 2019;Nelufule et al 2020). Some popular mammal species in the pet trade, such as the sugar glider, have previously been reported to have relatively high potential ecological risk (da Rosa et al 2018).…”

Ranking alien species based on their risks of causing environmental impacts: A global assessment of alien ungulates

“…EICAT was recently adopted by the International Union for Conservation of Nature (IUCN) as its formal classification system of alien species' impacts (IUCN, 2020a). So far, EICAT has been implemented to classify the impacts of alien birds (Evans et al, 2016) and amphibians (Kumschick et al, 2017), marine fishes invasive to the Mediterranean (Galanidi et al, 2018), alien bamboos (Canavan et al, 2019), gastropods alien to South Africa (Kesner & Kumschick, 2018), alien terrestrial invertebrates in the pet trade of South Africa (Nelufule et al, 2020) and feral mammals in South Africa (Hagen & Kumschick, 2018).…”

Tarantulas (Araneae: Theraphosidae) in the pet trade in South Africa

“…In South Africa, a range of taxa are kept as pets (van Wilgen et al 2008;van Wilgen et al 2010;Nunes et al 2017;Maligana et al 2020;Shivambu et al 2020c). Studies have investigated amphibians, reptiles and fishes in the pet trade (van Wilgen et al 2008;Woodford et al 2017;Measey et al 2017), but only one study has explored risks associated with invertebrates (Nelufule et al 2020). Several species of tarantula (spiders in the family Theraphosidae) are also traded and kept as pets.…”

“…Many species that escape, or are released, may be unable to survive and establish self-sustaining populations (Zenni and Nuñez 2013). However, those species that successfully establish and become invasive can have severe environmental and economic impacts (Nelufule et al 2020;Shivambu et al 2020aShivambu et al , 2020b. Some of the species damage ecosystems (Martin and Coetzee 2011), compete for resources with native species (Mori et al 2017;Nunes et al 2017) and carry pathogens that threaten public health (Travis et al 2011) and agriculture (Witmer andHall 2011;Gibson and Yong 2017), and cause biodiversity loss (Engeman et al 2007;Faulkes 2010).A recent review by Lockwood et al (2019) highlights the urgent necessity to understand better how the exotic pet trade contributes to invasions in order to devise strategies to limit its harmful impacts.…”