Salinity tolerance of marbled crayfishProcambarus fallaxf.virginalis

Abstract

-Eastern Europe comprises a significant part of the native ranges for indigenous crayfish species (ICS) belonging to the genus Astacus. This region has been largely overlooked by astacologists and considered relatively immune to the impacts of non-indigenous crayfish species (NICS). The recent discovery of two marbled crayfish Procambarus fallax f. virginalis populations in Ukraine has changed this view. Increased propagule pressure (mainly due to pet trade) has raised concerns of NICS which may negatively impair the ecosystems of Azov, Black and Caspian Seas and their tributaries inhabited by ICS. In this study, we provide the first insight into salinity tolerance of marbled crayfish. We performed a 155-day experiment using 5 different salinities (6, 9, 12, 15, and 18 ppt) and a freshwater control. Evaluation of survival, growth and reproduction suggests that marbled crayfish have a lower salinity tolerance than other crayfish species, which may limit their invasive potential in brackish environments. However, its ability to survive for more than 80 days at 18 ppt opens up the possibility of gradual dispersion and adaptation to brackish conditions. Our study highlights the need for further studies elucidating the potential for marbled crayfish to negatively impair these ecosystems.Keywords: brackish environment / growth / reproduction / moult / survival Résumé -Tolérance à la salinité de l'écrevisse marbrée Procambarus fallax f. virginalis. L'Europe de l'Est comprend une partie importante des régions abritant des espèces indigènes d'écrevisses (ICS) appartenant au genre Astacus. Cette région a été largement ignorée par les astacologues et considérée comme relativement protégée des impacts des espèces d'écrevisses non indigènes (NICS). La découverte récente de deux populations d'écrevisses marbrées Procambarus fallax f. virginalis en Ukraine ont changé cette vision. Le potentiel d'augmentation de la pression des propagules (principalement en raison du commerce des animaux de compagnie) a soulevé des préoccupations concernant les NICS qui pourraient nuire aux écosystèmes des mers d'Azov, Noire et Caspienne et à leurs affluents habités par des ICS. Dans cette étude, nous fournissons le premier aperçu de la tolérance à la salinité des écrevisses marbrées. Nous avons effectué une expérience de 155 jours en utilisant 5 salinités différentes (6, 9, 12, 15, 18 ppt) et un contrôle d'eau douce. L'évaluation de la survie, de la croissance et de la reproduction suggère que les écrevisses marbrées ont une tolérance à la salinité plus faible que les autres espèces d'écrevisses, ce qui peut limiter leur potentiel invasif dans les milieux saumâtres. Cependant, sa capacité à survivre pendant plus de 80 jours à 18 ppt ouvre la possibilité d'une dispersion progressive et d'une adaptation aux conditions saumâtres. Notre étude souligne la nécessité de poursuivre les études permettant d'éclaircir le potentiel de l'écrevisse marbrée à nuire négativement à ces écosystèmes.

Physiological properties and tailored feeds to support aquaculture of marbled crayfish in closed systems

“…While this is feasible and cost-effective for the hatchery and nursery stages, closed systems would represent a major economic disadvantage for the growout stage, which requires large surfaces. However, marbled crayfish are known to have very low salinity tolerance 45 . Based on the available information 45 12.206505E) was analyzed.…”

Introduced alien signal crayfish (Pacifastacus leniusculus) in Finland − uncontrollable expansion despite numerous crayfisheries strategies

“…Freshwater crayfish tolerate saline water to some extent (e.g., Holdich et al, 1997;Vesely et al, 2017) but have not been reported to reproduce in high salinity waters (Holdich et al, 1997). However, low-saline estuaries and coastal areas could potentially act as invasion corridors between rivers (Dobrzycka- Krahel et al, 2017;Vesely et al, 2017).…”

“…However, low-saline estuaries and coastal areas could potentially act as invasion corridors between rivers (Dobrzycka- Krahel et al, 2017;Vesely et al, 2017). Experimental signal crayfish introduction were carried out in the Finnish coastal area of Baltic Sea (salinity 1.5-6‰) in 1970's and 1980's, but no observations of established populations have so far been made (Järvenpää T. pers comm).…”

In-depth investigation of the species problem and taxonomic status of marbled crayfish, the first asexual decapod crustacean

“…Marbled crayfish and P. fallax were not yet found in brackish water. However, laboratory experiments revealed that marbled crayfish can survive salt concentration up to 18 ppt for more than 80 days but growth and reproduction stops at 6 ppt (Veselý et al, 2017).…”

“…Both crayfish probably do not burrow by preference but when the water table is lowered in the dry season (Hobbs, 1981;Jones et al, 2009;Chucholl et al, 2012;van der Heiden, 2012), Marbled crayfish and P. fallax were not yet found in brackish water. However, laboratory experiments revealed that marbled crayfish can survive salt concentration up to 18 ppt for more than 80 days but growth and reproduction stops already at 6 ppt (Veselý et al, 2017).…”