Environmental stressors profoundly influence how animals learn and remember, yet different types of stress can trigger distinct behavioural and molecular outcomes. Understanding this is essential for decoding adaptive responses in ecological settings and also for informing translational models of stress-related cognitive dysfunction. The pond snail Lymnaea stagnalis offers a powerful platform for such investigations. Despite their simplicity compared to mammals, they exhibit higher-order associative learning, such as the Garcia effect, where a novel taste cue, when associated over a time gap (which can be hours) with sickness (induced by acute heat shock), causes the snails to avoid the novel food. The snails also show configural learning, which occurs when a positive (food cue) and negative stimulus (predator odour) are presented simultaneously, leading to the formation of a ‘fear landscape’, and the consequent avoidance of the positive food cue. In this study, we extend these existing paradigms by using biologically relevant stressors: a predator-attack-mimicking shell clip (ShC) and acute heat shock (HS). We found striking, stressor-specific differences in behavioural outcomes: ShC supported configural learning but not the Garcia effect, while HS induced the Garcia effect but failed to support configural learning. Along with behaviour, we show distinct transcriptional changes in the central ring ganglia, affecting expression levels of key targets including stress- and plasticity-related genes, serotonergic markers and enzymes of the endocannabinoid system. Together, these results suggest that different stressors establish unique internal stress states (‘fear’ versus ‘sickness’) that selectively shape learning pathways. This study highlights a critical principle in neuroscience: stress is not a monolith, and its impact on learning and memory depends on both its nature and the internal state it evokes. This finding holds direct relevance for understanding stress-related psychiatric disorders and maladaptive behaviours. • Stressor type determines if snails form configural learning or the Garcia effect. • Shell clip enables configural learning and heat shock supports the Garcia effect. • Stressors produce distinct transcriptional profiles in central ring ganglia. • Changes involve stress-, plasticity-, serotonin- and endocannabinoid-related genes. • The impact of stress on memory depends on the internal state produced.

Territorial behaviour can facilitate the defence of resources but becomes disadvantageous when resources are mobile and move beyond territory boundaries. In such cases, animals may develop strategies to retain access to these resources within their territory. Here, we describe a novel behaviour in the territorial Mediterranean rainbow wrasse, Coris julis , which joins producer–scrounger aggregations with a goatfish species, Mullus surmuletus , that disturbs benthic prey during foraging. Wrasse remained within their territories and did not follow producers beyond these boundaries but repeatedly engaged in tactile interactions (brief physical contact using their ventral side and pelvic fins or caudal fin) with goatfish while they were present. Events involving tactile interactions were associated with longer feeding durations of goatfish and therefore, indirectly, a higher overall food uptake for wrasse. During these events, wrasse also had increased rates of food uptake, possibly due to the close proximity to the producer and the disturbed prey. In general, feeding with goatfish was beneficial for wrasse when compared to foraging alone. Although goatfish feeding durations were longer when tactile interactions occurred, their movement patterns through the environment were unaffected by the presence or tactile contact of wrasse. While a causal relationship between tactile contacts and length of feeding time could not be established, the underlying mechanism may involve a physiological effect on goatfish, such as by reducing stress or functioning as a reassuring safety cue. Our findings describe a novel example of tactile interactions in a marine system and may suggest a behavioural strategy that could increase access to food resources within territorial boundaries, ultimately mitigating a cost of territoriality. • Territorial scroungers show tactile interactions with heterospecific food-producers. • Tactile interactions were associated with longer feeding aggregations. • Scroungers did not follow mobile producers beyond their territorial boundaries. • Scrounging with producers resulted in higher food uptake than foraging alone. • Tactile contact further increased food uptake rates, likely due to close proximity.

Chemical communication plays an important role during many mating interactions. Female chemical signalling for mate attraction is expected to vary based on the females’ state in order to maximize fitness, to attract males when females are fertile adults and to avoid superfluous matings; for example, during maternal care. We tested if females of the spider Pisaura mirabilis vary in their silk-bound signalling during developmental, reproductive and maternal care states by observing male courtship responses upon contact with their silk lines. We expected females to signal, and males to increase their courtship efforts, when adults (as opposed to juveniles or subadults) and when free from tending their eggs. Males were indeed more likely to court silk of sexually receptive adult females and less likely to court silk of egg-carrying females. This may suggest variation in female signalling, pointing to costs of continued mate attraction during maternal care. Egg fertilization appears to be an important factor linking maternal care to signalling, as males courted silk of egg-caring mated females less than that from unmated females with unfertilized eggsacs. Insemination alone, on the other hand, is not relevant, as we found no differences between courtship of silk of unmated and mated females, probably due to the nutritional benefits of male nuptial gifts and the indirect benefits of polyandry to females. In such a system, selection is likely to favour male discriminatory abilities to reduce reproductive costs associated with nuptial gifts. • Males vary in their response to female silk. • Female-silk-borne communication is state dependent • Females with fertilized eggsacs induce reduced male courtship responses. • Fertilization and egg care but not insemination affect female-silk-borne signalling.