Effect of lamellae autotomy on survival and foraging success of the damselfly Lestes sponsa (Odonata: Lestidae)

Abstract

Damselfly larvae can autotomize their caudal lamellae to escape predation. Costs of caudal lamellae autotomy were investigated by directly manipulating lamellae condition of Lestes sponsa in laboratory experiments. Larvae without lamellae had higher predation mortality in the presence of Notonecta. Both lamellae loss and larval density increased the probability of being cannibalized. The results suggest that the increased vulnerability after lamellae loss resulted from a reduced escape performance. Larvae were less mobile after lamellae loss or in the presence of a predator, but the decrease was no longer significant when both factors were combined. This indicates that larvae compensate for the increased predation risk with a fixed response. Both lamellae loss and predator presence reduced hunting success, but the decrease after lamellae loss was only significant in the absence of a predator. The fitness consequences of these effects for both the larval and adult stages are discussed. In general, the data strongly suggest that lamellae autotomy plays a role in population regulation of damselflies.

Ecological effects of pharmaceuticals in aquatic systems—impacts through behavioural alterations

“…A bold individual would start moving sooner rather than later compared to a shy one, after being disturbed by a potential predator. We scored larval activity levels following the protocols developed by Stoks [92] and later repeatedly validated [93,94]. Activity assays were carried out in aquaria (25 Â 25 Â 8 cm, filled with 1.2 l aged tap water) with a coordinate grid (1 Â 1 cm) drawn on the bottom.…”

Eco-mechanics of lamellar autotomy in larval damselflies

“…Larval damselfly face two classes of predators that can generate diversifying selection on lamellae and other traits: large predatory fish, and large predatory invertebrates such as larval dragonflies that predominate in the absence of fish (McPeek, 1990a;McPeek, 1990b;McPeek et al, 1996;Strobbe et al, 2011). Autotomy of caudal lamellae enhances escape and survival against grasping predators such as larval dragonflies (Baker and Dixon, 1986;Stoks, 1998;McPeek, 1990b), but is ineffective against larger fish predators that swallow larvae whole (Baker and Dixon, 1986;McPeek, 1990b). However, evasive swimming is also more effective against attacking dragonfly larvae than against fish predators (Gyssels and Stoks, 2005), and so larger lamellae that enhance escape swimming performance can be favoured in ponds with high dragonfly predation risk (McPeek, 1997).…”

“…Thus, the lamellar joint may mediate a trade-off under dragonfly predation between structural support for larger lamellae that enhances evasive swimming and structural support for smaller lamellae that enhances lamellar autotomy (Bose and Robinson, 2013). Losing lamellae can have additional costs related to survival, such as decreased swimming performance (Robinson et al, 1991a;Burnside and Robinson, 1995;McPeek et al, 1996;Stoks, 1999b;Gyssels and Stoks, 2005), which can impair future escape attempts (Gyssels and Stoks, 2005); reduced attempts at escape under predation threat (Robinson et al, 1991a;Gyssels and Stoks, 2005); greater risk of being cannibalised by conspecifics (Stoks, 1998); and reduced oxygen consumption (Eriksen, 1986;Robinson et al, 1991b), foraging (Stoks, 1999a) and growth (Stoks, 2001). These costs may be lessened by regenerating missing lamellae in as little as two moults (Robinson et al, 1991b), but they also strongly suggest substantial survival benefits of lamellar autotomy.…”

“…Autotomy may be advantageous if it provides a last-ditch escape strategy by a prey organism. Appendage loss must also be costly (Robinson et al, 1991a;Gyssels and Stoks, 2005), but the immediate survival benefits of predator escape must sometimes outweigh such disadvantages for autotomy to evolve (Robinson et al, 1991b;Stoks, 1998;Fleming et al, 2007). Appendages that are not essential for survival, but that are frequently a target of attack, may reduce the costs of autotomy (Fleming et al, 2007).…”

Peripheral injury induces long-term sensitization of defensive responses to visual and tactile stimuli in the squid Loligo pealeii, Lesueur 1821

“…Various ecological studies have demonstrated survival costs of injuries, e.g. in tadpoles (Semlitsch, 1990;Figiel and Semlitsch, 1991) and larval damselflies (Stoks, 1998), but we know of no studies of the consequences of injuryinduced behavioral sensitization for survival or predation. While it seems likely that experiencing an injury greatly increases mortality risk, the value of long-term nociceptive sensitization for reducing these costs remains unclear.…”