The effect of inter- and intra-specific competition on survival and growth rate of native juvenile noble crayfish Astacus astacus and alien spiny-cheek crayfish Orconectes limosus

Abstract

Juvenile noble crayfish, Astacus astacus and spiny-cheek crayfish, Orconectes limosus were reared from the 2nd and the 3rd developmental stage (i.e. since the stage of independence), respectively, until the end of the growing season. The first period revealed very low survival rate of O. limosus in the communal stock (7 ± 6.2%), probably caused by predation of A. astacus. Separately reared O. limosus proved significantly higher survival rate (49 ± 9.2%) than those in the communal stock with A. astacus. The latter species also showed the highest survival rate in this case (90 ± 7.1%). This was not found to differ from the survival rate of separately reared noble crayfish (86 ± 3.1%). In general, both the significant effect of bigger size of A. astacus than that of O. limosus and higher intra-specific cannibalism of O. limosus were reflected during the first phase of rearing. Size and weight of both species were equivalent 11 weeks after hatching (8 weeks of rearing). The higher cumulative survival rate was reached in the intraspecific culture of A. astacus (90%) while low cumulative survival of both species was found in communal stock (less than 50%) in the second phase of rearing. At the end of the growing season, 19-week-old O. limosus attained a higher mean size and weight but were more variable in the group (29.3 ± 5.17 mm and 616.4 ± 412.53 mg) than A. astacus (21.2 ± 1.82 mm and 229.9 ± 59.45 mg). Single and communal stock did not differ. Growth of O. limosus was much faster than that of A. astacus.

Invaders eating invaders: potential trophic interactions between the amphipodDikerogammarus villosusand juvenile crayfishOrconectes limosus

“…This is probably caused by the small size of newly independent O. limosus juveniles (Andrews, 1907), which may also explain the high vulnerability of O. limosus 3rd DS to the predation pressure of D. villosus, and their very low survival in both fed and unfed mixed treatments. The effect of the smaller size of O. limosus was also observed in interactions with Astacus astacus juveniles (Kozák et al, 2007). The high level of cannibalism, common in juvenile O. limosus (Kozák et al, 2007), probably reduced survival in unfed single-species stock of O. limosus; we did not observe a similar survival decrease in the unfed stock of the amphipod.…”

“…The effect of the smaller size of O. limosus was also observed in interactions with Astacus astacus juveniles (Kozák et al, 2007). The high level of cannibalism, common in juvenile O. limosus (Kozák et al, 2007), probably reduced survival in unfed single-species stock of O. limosus; we did not observe a similar survival decrease in the unfed stock of the amphipod. Our results are in accordance with the known great predatory capability of D. villosus.…”

Growth performance of Noble Crayfish Astacus astacus in recirculating aquaculture systems

“…This is due to culture conditions (related to behavior), restrictions in Europe, workload, and operating and maintenance costs. O. limosus is already cultured in RAS (Auvergne 1979) but is much smaller and barely cannibalistic in contrast to A. astacus (Kozák et al 2007). The state-of-the-art method for culturing A. astacus and other crayfish species remain OPS (Ackefors 2000;Ó Sullivan et al 2012;Wickins and Lee 2002;Huner 1994), where sufficient space is available to reduce cannibalism, and food is, at a minimum, partially supplied by the pond itself.…”

Evaluation of body appendage injuries to juvenile signal crayfish (Pacifastacus leniusculus): relationships and consequences

“…Chelae, which perform several functions, are considered among the most important. They are used in mating (Snedden, 1990;Reynolds, 2002), defence against predators (Roth and Kitchell, 2005), inter-and intra-specific interactions (Garvey and Stein, 1993;Bergman and Moore, 2003;Kozák et al, 2007), and, to some extent, capture and manipulation of prey (Keller and Hazlett, 1996). In addition, male chelae are equipped with sensory structures that aid in the discrimination and localization of female scent Moore, 2006, 2009;Belanger et al, 2008).…”