Resistance to dehydration and positive hygrotaxis in the invasive red swamp crayfish Procambarus clarkii

Abstract

The red swamp crayfish Procambarus clarkii is the most cosmopolitan invasive freshwater crayfish species in the world. High tolerance to a wide range of environmental conditions, among which its great ability to survive drought conditions, and the economic importance are the main factors of its spreading success. The present study tests for the first time the survival of this species to different relative humidity (RH) conditions (plastic boxes with humidity controlling salt solutions at 30%, 50%, 70%, 100% RH) and its ability to orient in humidity gradients (dual-choice chambers 50–78% RH, 60–75% RH). P. clarkii shows a great ability to survive out of water, positively related to the RH conditions, surviving more than two days at very low humidity (30% RH) and more than one month at 100% RH. In addition the crayfish showed a positive hygrotaxis spending most of their time in the area of the choice chambers with a higher RH. The results of the present investigation are particularly relevant considering that one of the major challenges to predict and control biological invasion lies in understanding which biological and ecological features might favor the colonization of alien invasive species in new areas.

Terrestrial emigration behaviour of two invasive crayfish species

“…In terms of both red swamp and signal crayfish, the present study shows that terrestrial movement could be an equally important factor in the spread of both species, which are known to survive long periods out of water and in drought conditions (Cruz and Rebelo 2007;Holdich et al 2014;Banha and Anastácio 2014). The red swamp crayfish, however, is generally considered to be more adept at overland dispersal, tolerating long periods out of water (Piersanti et al 2018) and extending survival on land by constructing burrows and inhabiting small puddles whilst also feeding on terrestrial vegetation (Grey and Jackson 2012;Ramalho and Anastácio 2015;Kouba et al 2016;Souty-Grosset et al 2016). In their native North American range, burrowing has not been recorded in signal crayfish and some studies show that this species is incapable of constructing burrows (Kouba et al 2016), suggesting it is less adapted to terrestrial habitats.…”

“…Some crayfish, particularly burrowing species, can survive for several months out of water in burrows (Huner and Linqvist 1995;Kouba et al 2016) though all crayfish can tolerate some degree of terrestrial exposure. Of the nine non-native crayfish species in Great Britain, red swamp and signal crayfish are most frequently reported dispersing overland, at least in other parts of the world (Holdich et al 2014;Ramalho and Anastácio 2015;Piersanti et al 2018). Red swamp crayfish can move up to 1 km (Lutz and Wolters 1999; Souty-Grosset et al 2016) at a speed of 90 m h -1 (Ramalho and Anastácio 2015).…”

Seasonal and perennial water populations of an endemic crayfish differ in behavioural responses to drying but not metabolism

“…Our findings suggest freshwater crayfish occupying seasonal habitats may possess physiological adaptations to drying, possibly through local selection. For example, they may be more able to sense and orientate to humidity due to more sensitive hygroreceptors on their antennae (Piersanti et al, 2018). Physiological adaptations may be coupled with behavioural responses, such as seeking moist microhabitat (e.g., Claussen et al, 2000) or small crayfish cohabiting in burrows with larger adults to survive drying (Guo et al, 2019).…”

“…Even a small percentage of clay mixed with sand enabled the sediment to hold its shape so that burrows reached subsurface water. This likely accounted for the higher survival of Bull Creek crayfish in clay versus sand as higher humidity increases survival (e.g., P. clarkii survived a month in 100% humidity vs. 2 days in 30%; Piersanti et al, 2018). In sand, where Bull Creek crayfish could not burrow adequately, they instead plugged the shelter entrances (e.g., akin to Fallicambarus gordoni , Welch et al, 2008; and Geocharax sp.…”

Population Ecology and Genetic Diversity of the Invasive Alien Species Procambarus clarkii in Lake Trasimeno (Italy)

“…Its biological plasticity and resistance to environmental pollution determines its extreme invasiveness, competitiveness and aggressiveness with native species, making it almost impossible to eradicate from a territory once established. Indeed, P. clarkii is able to survive in waters with low oxygen concentration and can even survive out of water for a period of more than two days with a very low relative humidity level (30% RH) and for more than a month at 100% RH [6]. In dry periods, the species digs deep burrows (40-90 cm) which are also useful during the most delicate phases of its life cycle (molting and reproduction).…”