The redclaw crayfish: A prominent aquaculture species with invasive potential in tropical and subtropical biodiversity hotspots

Abstract

The redclaw crayfish (Cherax quadricarinatus; hereafter redclaw), native to northern Australia and southern New Guinea, is among the largest freshwater decapods. It matures early and is considered highly prolific as females may lay over one thousand eggs in a single clutch. Despite generally preferring slow-moving streams in its native range, it has a wide environmental tolerance, making it capable of establishing populations when introduced to a wide range of other conditions and habitats. These biological and ecological features render it a highly suitable and popular species for aquaculture worldwide, being the second most important crayfish species economically (after the red swamp crayfish Procambarus clarkii). Adding to that, its unique coloration fuels demand and value among aquarium enthusiasts, making it attractive for the aquarium pet trade. Today, redclaw is widely translocated (67 countries/territories) and various established wild populations (22 countries) have been reported on every continent except Antarctica. Information on its potential or observed impacts, however, is sparse and often anecdotal. To address this gap, this comprehensive review compiles all available information on this species, covering its taxonomy and description, biology and ecology, native and non-native ranges accompanied with documented introduction pathways. Built upon these, we conducted biological and socio-economic classification and species distribution modelling. We reveal a lack of thorough impact assessments for this species despite sufficient indications of major observable impacts at local scales. We call attention to the importance of managing the use of this prominent introduced species in aquaculture and aquarium pet trade.

Survival, Growth, and Reproduction: Comparison of Marbled Crayfish with Four Prominent Crayfish Invaders

“…In our study, the species successfully exceeded 20 g in 18 weeks; thus, it is not surprising that this warm-water species is of great interest to crayfish aquaculture [66,67]. However, global crayfish aquaculture is mostly focused on the red swamp crayfish [68,69]. Its total body length usually ranges from 10 to 12 cm, but can reach up to 20 cm in exceptional cases [61].…”

Redclaw crayfish (Cherax quadricarinatus): spatial distribution and dispersal pattern in Java, Indonesia

“…For example, by reducing biomass of aquatic plants, crayfish reduce the availability of shelters for macroinvertebrates and fishes (James et al, 2015). Cherax quadricarinatus can also negatively affect native species, through direct competition, predation, or habitat modification, and may host parasites previously absent in native populations (Haubrock et al, 2021). For instance, various species of bacteria are known to infect C. quadricarinatus (Hayakijkosol et al, 2017).…”

“…Although the western part of New Guinea belongs to Indonesian territory, the species has to be perceived intranationally as non-native in the rest of the country (Bláha et al, 2016). The purpose of new introductions of C. quadricarinatus is usually related to its economic value for human consumption and ornamental trade (Negara, 2012;Haubrock et al, 2021). Both purposes were previously recorded also in Indonesia (Patoka et al, 2018b).…”

“…In comparison with other members of this genus (Weiperth et al, 2020), C. quadricarinatus is highly adaptable to various water quality parameters such as different levels of oxygen, ammonia, hardness, alkalinity, and pH (Rouse et al, 1991). This crayfish is able to live in waters with water temperatures ranging from 10 to 31°C (Haubrock et al, 2021).…”

Another hitchhiker exposed: Diceratocephala boschmai (Platyhelminthes: Temnocephalida) found associated with ornamental crayfish Cherax spp.

“…Global pet trade with increasing attractivity of ornamental decapods together with their current commercial availability is considered as a relevant risk of alien hitchhikers future introductions (Chucholl and Wendler, 2017;Yonvitner et al, 2020). Additionally, the high invasive potential of C. quadricarinatus, the species widely used in aquaculture and introduced to many countries out of the original area of distribution has recently been discussed (Akmal et al, 2021;Haubrock et al, 2021) and thus representing high potential risk of native epibionts introductions. Even if policymakers generally focused on regulation of spread and introductions of potentially invasive species in European Union (Regulation (EU) No 1143/2014), the current legislative framework is ineffective in many cases (Patoka et al, 2018).…”