The effects of crayfish predation on phenotypic and life-history variation in fathead minnows

Abstract

Ecological theory predicts that the timing of the transition between life-history stages should vary with the costs and benefits associated with each stage. For example, the timing of hatching or metamorphosis may vary with the predation risk in each stage. Predator-induced changes in hatching time are well documented in some taxa but have not been reported in fishes. We provide the first empirical evidence that a species of fish can alter its hatching time in response to predator cues. We showed that fathead minnows, Pimephales promelas Rafinesque, 1820, exposed to chemical cues from virile crayfish, Orconectes virilis (Hagen, 1870), foraging on minnow embryos hatch sooner than those exposed to a blank control. Moreover, in the presence of cues from virile crayfish feeding on minnow embryos, the hatchlings exhibited a change in morphology because they had significantly shorter total lengths. There was a significant positive correlation between hatchling size and length of the developmental period, except in the high predation threat treatment. By hatching earlier, the fathead minnows escaped predation from virile crayfish that were actively foraging on fathead minnow eggs. Hatching at a smaller size, however, may make the fry more vulnerable to other predators.

Flexible information sampling in vibrational assessment of predation risk by red-eyed treefrog embryos

“…similarly context-dependent hatching timing has been shown in other taxa (Sih and Moore, 1993;Chivers et al, 2001;Li, 2002;Wedekind, 2002;Kusch and Chivers, 2004;Moreira and Barata, 2005). Here we show that A. callidryas embryos also modulate the amount of information on which their hatching decision is based depending on the amount of time, or risk, entailed in gathering that information.…”

Pathogen-induced hatching and population-specific life-history response to waterborne cues in brown trout (Salmo trutta)

“…Cues from both predators (Moore et al 1996;Smith and Fortune 2009;Miner et al 2010) and pathogens (Kiesecker et al 1999;Wedekind 2002) have been observed to alter hatching time. These cues can be quite specific, allowing animals to distinguish between predators and nonpredators, and even predator diets (Chivers et al 2001;Kusch and Chivers 2004). Induced responses can equally be elicited from injured or infected conspecifics (Kiesecker et al 1999;Chivers et al 2001;Wedekind 2002;Miner et al 2010).…”

Should I stay or should I go: predator- and conspecific-induced hatching in a marine snail

“…Treefrogs embryos that hatch early because of a snake enter the pond at a smaller size and are more susceptible to predators that prey upon free-living larvae (Warkentin 1995). To date, predators are known to alter, either accelerate or delay, time-to-hatching in 14 species of frog (reviewed by Warkentin 2007), a species of salamander (Moore et al 1996;Sih and Moore 1993), a species of Wsh (Kusch and Chivers 2004), a species of spider (Li 2002), and a species of fairy shrimp (De Roeck et al 2005). Evidence suggests that the presence of predators also aVects when a mosquito and some crustaceans hatch (Blaustein 1997;Livdahl et al 1984).…”