How do developmental and parental exposures to predation affect personality and immediate behavioural plasticity in the snail Physa acuta ?

Abstract

Individuals differ in personality and immediate behavioural plasticity. While developmental environment may explain this group diversity, the effect of parental environment is still unexplored—a surprising observation since parental environment influences mean behaviour. We tested whether developmental and parental environments impacted personality and immediate plasticity. We raised two generations of Physa acuta snails in the laboratory with or without developmental exposure to predator cues. Escape behaviour was repeatedly assessed on adult snails with or without predator cues in the immediate environment. On average, snails were slower to escape if they or their parents had been exposed to predator cues during development. Snails were also less plastic in response to immediate predation risk on average if they or their parents had been exposed to predator cues. Group diversity in personality was greater in predator-exposed snails than unexposed snails, while parental environment did not influence it. Group diversity in immediate plasticity was not significant. Our results suggest that only developmental environment plays a key role in the emergence of group diversity in personality, but that parental environment influences mean behavioural responses to the environmental change. Consequently, although different, both developmental and parental cues may have evolutionary implications on behavioural responses.

Among‐individual behavioral responses to predation risk are invariant within two species of freshwater snails

“…In both species, all conspecific snails increased avoidance behavior to the same degree with increasing risk. A recent study on Physa also failed to detect individual differences in the behavioral response to risk (Tariel et al, 2020), albeit with less experimental power (i.e., fewer individuals, risk levels, and replicates) than the present study.…”

On the use of antibiotics in plasticity research: Gastropod shells unveil a tale of caution

“…Thus, we consider maternal lineage as family identity so as account for genetic effects. Immediately after hatching, we separated individuals into a fully factorial 2 × 2 split-clutch design, where we crossed a 5-day antibiotic treatment (25 mg L −1 erythromycin, MardFritz Aquaticsel Maracyn; Fritz Aquatics) as outlined by DeWitt and Prestridge (2022) or a sham water control treatment with a follow-up regular exposure (three times per week as described in Auld & Relyea, 2010b, 2011 to either perceived high-risk (conspecific alarm cues, one crushed snail per four litres of water as described in Tariel et al, 2020aTariel et al, , 2020b or low-risk (clean water) for 28 days. Conspecific alarm cues are a reliable indicator of elevated predation risk across taxa (Chivers & Smith, 1998).…”

Sensitive windows for within- and trans-generational plasticity of anti-predator defences

“…The WGP of inducible defences of P. acuta have been well described. In presence of crayfish olfactory cues, snails (1) are more often at the surface or out of the water (out of reach of crayfish as crayfish consume snails at the bottom of the water column; Alexander and Covich 1991a,b;Covich et al 1994;McCarthy and Dickey 2002;Turner et al 1999), and (2) crawl back to the surface more quickly (Tariel et al 2020a). In addition, snails which have perceived crayfish cues during their development (3) have a larger and thicker shell making them more difficult to crush and handle -crayfish feed first on small and thin-shelled Physa snails (Alexander and Covich 1991a;Auld and Relyea 2011;Bukowski and Auld 2014;DeWitt et al 2000;Rundle and Brönmark 2001;Salice and Plautz 2011;Stevison et al 2016);and (4) reproduce later and at a larger size compared to snails which have not perceived crayfish cues (Crowl and Covich 1990).…”