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Social experiences can shape adult behavior and cognition. Here, we use El Abra swordtails (Xiphophorus nigrensis) to assess how life-long experience with different male mating tactics shapes coercion evasion ability and female spatial cognition. We raised females from birth to adulthood in environments that varied by male mating tactic: coercers only, courtship displayers only, coercers and displayers together, mixed-strategists, and female only. In adulthood, we tested females’ behavioral responses to a coercive male and spatial cognition in a maze. Females reared with only displayers were significantly worse at distancing themselves from the coercive male than females raised with coercers and displayers and females raised with only coercers. Females raised with a single mating tactic (either courtship display or coercion) exhibited significantly higher accuracy in the spatial maze than females from other rearing groups, and showed significant reduction in total errors (courtship display group) or latency to reward (coercion group) over successive trials. These more predictable environments (one tactic), and not the more complex environments (two tactics), showed evidence for spatial learning. The results are discussed in light of the existing literature on two components of environmental change (environmental predictability and the certainty with which cues predict the best behavioral response) and their effect on the development of cognitive abilities.
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Establishing optimal broodstock sex ratios for the royal gramma (Gramma loreto) in small scale system aquaculture
The royal gramma (Gramma loreto) is vulnerable to anthropogenic impact in its coral reef habitats, and is deemed an “indicator” species of pollution. It is also heavily fished for the aquarium trade, being among the top 1% of imported marine aquarium fish species into the U.S. The objective of this study was to establish optimal sex ratios of broodstock groups for aquaculture as an alternative to wild capture, while balancing territorial aggression. Three two-month breeding trials were carried out in six 23 L aquaria stocked with one male and one, two, or three females. During the trials, each aquarium was filmed weekly for one hour at first light to record courtship, nest use, and aversive behaviors. Behaviors were quantified with JWatcher software and analyzed in repeated measures ANOVAs. Results suggest that in small aquaria, a sex ratio of one male to two females may be optimal for spawning because courtship and nest use behaviors are optimized while aversive behaviors are moderated. Past efforts to aquaculture the species have typically been conducted at broodstock sex ratios of 1:1. These results offer the potential to increase productivity of commercial aquaculture of the species.
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- Award ID(s):
- 1658663
- PAR ID:
- 10351506
- Date Published:
- Journal Name:
- Aquaculture
- Volume:
- 543
- ISSN:
- 0044-8486
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Synopsis Animals use visual communication to convey crucial information about their identity, reproductive status, and sex. Plasticity in the auditory and olfactory systems has been well-documented, however, fewer studies have tested for plasticity in the visual system, a surprising detail since courtship and mate choice are largely dependent on visual signals across taxa. We previously found reproductive state-dependent plasticity in the eye of the highly social cichlid fish Astatotilapia burtoni. Male A. burtoni increase their courtship, including multicomponent visual displays, when around ovulated females, and ovulated females are more responsive to male visual courtship displays than non-ovulated females. Based on this, we hypothesized that ovulation status impacts visual capabilities in A. burtoni females. Using electroretinograms, we found that ovulated females had greater visual sensitivity at wavelengths corresponding to male courtship coloration compared with non-reproductively-receptive females. In addition, ovulated females had higher neural activation in the retina and higher mRNA expression levels of neuromodulatory receptors (e.g., sex-steroids; gonadotropins) in the eye than non-ovulated females. Here, we add to this body of work by testing the hypothesis that cone opsin expression changes with female reproductive state. Ovulated females had higher expression of short wavelength sensitive opsins (sws1, sws2a, sws2b) compared with mouthbrooding females. Further, expression of sws2a, the most abundant opsin in the A. burtoni eye, positively correlated with levels of circulating 11-ketotestosterone and estradiol and estrogen, androgen, and gonadotropin system receptor expression in the eye in females. These data indicate that reproductive state-dependent plasticity also occurs at the level of photoreceptors, not just through modulation of visual signals at downstream retinal layers. Collectively, these data provide crucial evidence linking endocrine modulation of visual plasticity to mate choice behaviors in females.more » « less
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Abstract Temperature influences the expression of a wide range of behavioral traits in ectotherms, including many involved in the initiation of pair formation and mating. Although opportunities to mate are thought to be greatest when male and female activity overlap, sex‐specific behaviors and physiology could result in mismatched thermal optima for male and female courtship. Here, we investigate how conflicts in the thermal sensitivity of male and female courtship activity affect patterns of mating across temperatures inEnchenopa binotatatreehoppers (Hemiptera: Membracidae). These plant‐feeding insects coordinate mating with plant‐borne vibrational signals exchanged in male–female duets prior to pair formation. We manipulated temperature across an ecologically relevant range (18–36ºC) and tested the likelihood of individual male and femaleE. binotatato engage in courtship activity using vibrational playbacks. We then staged male–female mating interactions across the same temperature range and quantified the thermal sensitivity of mating‐related behaviors across stages of mating. Specifically, we measured the timing of duetting, the likelihood for key pre‐copulatory behaviors to occur, whether the pair mated, and copulation duration. We found sex‐specific thermal sensitivity in courtship activity: Males showed a clear peak of activity at intermediate temperatures (27–30ºC), while females showed highest activity at the hotter thermal extreme. Mating rates, courtship duets, and copulatory attempts were less likely to occur at thermal extremes. Also, duetting occurred earlier and copulation was shortest at higher temperatures. Overall, our data suggest that sexes differ in how temperature affects mating‐related activity and some processes involved in mate coordination may be more sensitive than others across variable thermal environments.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/j.aquaculture.2021.736931
