Pair-bonding influences affective state in a monogamous fish species

Abstract

In humans, affective states are a key component in pair-bonding, particularly in the early stage of a relationship. Pairing with a high-quality partner elicits positive affective states which, in turn, validate and reinforce the mate choice. Affective states thus strongly affect pair stability and future reproductive success. We propose generalizing the link between affective states and pair-bonding to encompass other monogamous species exhibiting biparental care, chiefly where the reproductive success of the pair critically depends on the coordination between partners. The convict cichlid Amatitlania siquia is a monogamous fish species that forms long-lasting pairs with strong cooperation between parents for parental care. In this species, we showed that females paired with their non-preferred male had lower reproductive success than those paired with their preferred male. We then transposed the judgement bias paradigm, previously used in other animal species, to assess objectively affective states in fishes. Females that were assigned their non-preferred partner exhibited pessimistic bias, which indicates a negative affective state. By contrast, females that were assigned their preferred partner did not exhibit changes in their affective state. Our results highlight that the influence of pair-bonding on affective states is not human-specific and can also be observed in non-human species.

Short telomeres drive pessimistic judgement bias in zebrafish

“…On the other hand, our results suggest the occurrence of a basic psychological mechanism, namely stimulus generalization, which has been proven to play an important role in responses to ambiguous stimuli in judgement bias paradigms (e.g. [15][16][17][18][19]). The occurrence of this mechanism is indicative of an accurate discrimination between a stimulus (or set of stimuli) that predicts a positive consequence and a stimulus (or set of stimuli) that predicts a negative one.…”

“…This type of experimental paradigm has been used in a wide range of species to assess judgement bias (e.g. [15][16][17][18][19][20][21][22]) (see electronic supplementary material for the detailed protocol of judgement bias assay for zebrafish).…”

Intranasal oxytocin drives coordinated social approach

“…Social defeat stress decreases OT receptor (OTR) gene expression in female California mice [19] and reduced OTR binding in the NAc corresponds to reduced social approach following defeat [61]. Moreover, plasma OT levels have been positively linked to attachment anxiety in romantic human relationships [62], and pair bonding influences affective state across taxa [63,64]. Because we did not directly measure stress or anxiety, we are unable to correlate individual differences in stress response to social approach or pair bonding-induced convergence.…”

Aggressive encounters lead to negative affective state in fish

“…Unfortunately, the inability to train shy fish in the JB test limited our ability to further explore the links between bold/shy behavioural traits and affective state. The change in affect following losing an aggressive encounter contributes to the emerging evidence of affective states being involved in decision-making in fish [11][12][13]. In fish, losing an aggressive encounter leads to a wide range of behavioural changes, which can be grouped into proactive (e.g.…”

“…Recent evidence is emerging indicating that decision-making in fish is influenced by affective state [11][12][13]. Affective state in animals is often demonstrated using go/no-go judgement bias tests (JB), in which subjects are trained to approach one stimulus to receive a reward and avoid a second stimulus in order to not receive a punisher, or receive a lower value reward.…”