Biology subjects

Jordan, A. L.

Publications and source records attributed to Jordan, A. L..

10 recordsLinked to original sources

bioRxiv2025

Cognitive ethology of nest building in a shell-dwelling cichlid

Across animal taxa, nest-building behavior is performed using a generalizable and flexible mental representation of an action sequence - a schema. In order to accomplish its goal (a stable nest), the brain appears to compare intermediate steps in the process to stored mental images, or templates. Deviations from these templates drive progress, preferences, and corrections in the execution of this behavior. The stereotypy vs. plasticity of both schema and mental templates have rarely been defined in an experimentally accessible system. Here we investigated nest building by the cichlid Lamprologus ocellatus, a fish species that manipulates abandoned snail shells to build shelters for breeding and protection. We find that nest building is composed of a sequence of behaviors that are tied together by a series of stimulus-response loops, allowing for restarts and shortcuts as the behavioral program unfolds. The attraction to a shell object is innate, as is the final appearance of the nest. The behavior in an inexperienced animal is initially uncoordinated, but is fine-tuned by repeated building opportunities. Shells need to conform to rigid geometric criteria in order to be acceptable as a potential home. Nest building is accompanied by focused neural activity in brain regions homologous to the mammalian hippocampus and neocortex. In conclusion, we have uncovered the constraints and flexibility of cognitive template matching underlying an instinctive, goal-directed behavior.

animal behavior and cognition↗

bioRxiv2025

Interactive delineation and quantification of anatomical structure with virtual reality

A virtual environment, equipped with suitable data representations, interaction techniques, and method interfaces, can facilitate effective human-in-the-loop analytics of 3D data. Motivated by this observation, we propose Brainacle, a native editor for the interactive delineation and quantification of anatomical structures in virtual reality. We validate this in a case study, where we process the gross brain regions of 20 individual animals from six different species of African cichlid fish from the tribe Lamprologinii, endemic to Lake Tanganyika in Africa. The software presented in this article can be used to quickly visualise and obtain an overview of imaged animal tissues, visually communicate features of interest, interactively add delineations, and perform different measurements in the same 3D environment. Brainacle is made available free of charge at https://brainacle.org and on the research data repository DaRUS.

bioinformatics↗

bioRxiv2025

Experimental study of social learning in three wild shell-dwelling Tanganyikan cichlids that vary in sociality

The social intelligence hypothesis posits that animals living in more complex social groups display better cognitive performances. However, this hypothesis has mainly been investigated in primates and studies using similar paradigms across different species are scarce. We tested three species of wild Lamprologine shell-dwelling cichlids from Lake Tanganyika (Neolamprologus multifasciatus, Lamprologus ocellatus, and Lamprologus ornatipinnis) that vary in their levels of sociality, in identical colour associative learning and social learning tasks. We found species differences in engagement in the training for these tasks and only 5 out of 24 individuals learnt to feed from a neutral object (a shell). One L. ocellatus and one L. ornatipinnis learnt to choose the correct colour in the associative learning task and were further used as demonstrators in the social learning task. In this task, no species showed signs of colour stimulus enhancement as the observers choices of colours were not influenced by the demonstrators. However, we found evidence for stimulus enhancement at a larger scale as naive observers approached the novel experimental apparatus faster than the demonstrators when first exposed to this apparatus. Our results encourage further research of social learning processes in individual fishes and highlights the difficulties in using identical paradigms in comparative psychology, even across very close species.

animal behavior and cognition↗

bioRxiv2025

Decision-making strategies of two related fish species diverge under increased perceptual load

Three main mechanisms have been proposed to explain divergent decisions between species faced with the same options: differences in sensory abilities, attentional capacities, or cognitive evaluations. While these mechanisms have been well-established in controlled settings, there is limited empirical evidence regarding the ways in which different species make decisions under varying perceptual loads. Here we investigated the decision-making processes of two closely related cichlid species, Aulonocranus dewindti and Cyathopharynx furcifer, in Lake Tanganyika. Males of these species construct sand bowers from which they remove foreign objects, and we examined their preferences when presented with objects varying in three attributes: colour, size, and shape. We show that both species exhibited similar preferences under low perceptual load. Similarly, when the perceptual load was increased by increasing the number of options, both species choices were driven by attentional capture, and an oddity effect was observed. However, when the perceptual load was increased by adding more attributes (feature conjunctions), the species diverged in their decision-making. One species, A. dewindti, evaluated the options in an absolute manner, considering all available attributes, as evidenced by its insensitivity to decoy effects. The other species, C. furcifer either showed attentional capture or evaluated the options in a comparative manner. We discuss the potential reasons behind these differences and their implications for the evolution of decision-making mechanisms.

animal behavior and cognition↗

bioRxiv2023

Brood care in shell-dwelling cichlids is timed by independent maternal and larval clocks

Successful brood care requires a finely tuned interplay between caregiving parent and offspring. Cichlids are a diverse group of teleost fish known for their extensive parental care of altricial young. Female Lamprologus ocellatus lay their eggs in the protective confines of an abandoned snail shell, where they raise them to free-swimming larvae. Here we investigated whether the transition to larval independence is driven by the behavior of the mother, the offspring, or an interaction between the two. Using 3D printed shells with a window, we were able to observe the behavior of both mother and offspring inside the nest using automated object detection and tracking. We found that, once hatched, the larvae remain in the deep chambers of the shell, and at 9 dpf, actively emerge from the shell during the day. An inversion of larval phototactic behavior from dark- to light-seeking leads up to this emergence. Removal of the mother causes premature emergence of the larvae by a few days. The natural schedule (emergence at 9 dpf) is restored if the larvae are supplied with fresh water in the mothers absence. In cross-fostering experiments, we found that swapping out the mothers own clutch for older larvae forces a delay in emergence, as the foster mother prevents the larvae from leaving at 9 dpf. We conclude that larval and maternal behavior are each controlled by independent internal clocks, which, although normally synchronized, can be experimentally manipulated and brought into conflict. This study has thus revealed an innate sequence of behavioral adaptations that orchestrate brood care in shell-dwelling cichlids.

evolutionary biology↗

bioRxiv2021

Differential neural activity patterns mediate learning across contexts in a social cichlid fish

Learning and decision-making are greatly influenced by the social context surrounding individuals. When navigating a complex social world, individuals must quickly ascertain where to gain important resources and which group members are useful sources of such information. Such dynamic behavioral processes require neural mechanisms that are flexible across contexts. Here we examined how the social context influences the learning response during a visual cue discrimination task and the neural activity patterns that underlie acquisition of this novel information. Using the cichlid fish, Astatotilapia burtoni, we show that learning of the task is faster in social groups than in a non-social context. We quantified the expression of Fos, an immediate-early gene, across candidate brain regions known to play a role in social behavior and learning, such as the putative teleost homologues of the mammalian hippocampus, basolateral amygdala, and medial amygdala/BNST complex. We found that neural activity patterns differ between social and non-social contexts. Our results suggest that while the same brain regions may be involved in the learning of a discrimination task independent of social context, activity in each region encodes specific aspects of the task based on context.

neuroscience↗

bioRxiv2020

Decontextualized learning for interpretable hierarchical representations of visual patterns

SO_SCPLOWUMMARYC_SCPLOWApart from discriminative models for classification and object detection tasks, the application of deep convolutional neural networks to basic research utilizing natural imaging data has been somewhat limited; particularly in cases where a set of interpretable features for downstream analysis is needed, a key requirement for many scientific investigations. We present an algorithm and training paradigm designed specifically to address this: decontextualized hierarchical representation learning (DHRL). By combining a generative model chaining procedure with a ladder network architecture and latent space regularization for inference, DHRL address the limitations of small datasets and encourages a disentangled set of hierarchically organized features. In addition to providing a tractable path for analyzing complex hierarchal patterns using variation inference, this approach is generative and can be directly combined with empirical and theoretical approaches. To highlight the extensibility and usefulness of DHRL, we demonstrate this method in application to a question from evolutionary biology.

evolutionary biology↗

bioRxiv2020

Structural manipulations of a shelter resource reveal underlying preference functions in a shell-dwelling cichlid fish

Many animals can modify the environments in which they live, thereby changing the selection pressures they experience. A common example of such niche-construction is the use, creation, or modification of environmental resources for use as nests or shelters. Because these resources often have correlated structural elements, it can be difficult to disentangle the relative contribution of these elements to resource choice, and the preference functions underlying niche-construction behaviour remain hidden. Here, we present an experimental paradigm that uses 3D-scanning, -modelling, and -printing to create replicas of structures that differ with respect to key structural attributes. We show that a niche-constructing, shelldwelling cichlid fish, Neolamprologus multifasciatus, has strong open-ended preference functions for exaggerated shell replicas. Fish preferred shells that were fully intact and either enlarged, lengthened, or had widened apertures. Shell intactness was the most important structural attribute, followed by shell length, then aperture width. We disentangle the relative roles of different shell attributes, which are tightly correlated in the wild, but nevertheless differentially influence shelter choice and therefore niche construction in this species. We highlight the broad utility of our approach when compared to more traditional methods (e.g. two-choice tasks) for studying animal decision-making in a range of contexts.

evolutionary biology↗

bioRxiv2020

High-resolution animal tracking with integration of environmental information in aquatic systems

Acquiring high resolution quantitative behavioural data underwater often involves installation of costly infrastructure, or capture and manipulation animals. Aquatic movement ecology can therefore be limited in scope of taxonomic and ecological coverage. Here we present a novel deep-learning based, multi-individual tracking approach, which incorporates Structure-from-Motion in order to determine the 3D location, body position and the visual environment of every recorded individual. The application is based on low-cost cameras and does not require the animals to be confined or handled in any way. Using this approach, single individuals, small heterospecific groups and schools of fish were tracked in freshwater and marine environments of varying complexity. Further, we established accuracy measures, resulting in positional tracking errors as low as 1.09 {+/-} 0.47 cm (RSME) in underwater areas up to 500 m2. This cost-effective and open-source framework allows the analysis of animal behaviour in aquatic systems at an unprecedented resolution. Implementing this versatile approach, quantitative behavioural analysis can employed in a wide range of natural contexts, vastly expanding our potential for examining non-model systems and species.

ecology↗

bioRxiv2019

Socially dominant, aggressive males are poor influencers of group-consensus in a social fish

In many species, cultures, and contexts, social dominance reflects the ability to exert influence over others, and the question of what makes an effective leader is pertinent to a range of disciplines and contexts. While dominant individuals are often assumed to be most influential, the behavioral traits that make them dominant may also make them socially aversive and thereby reduce their influence. Here we examine the influence of dominant and subordinate males on group behavior in different social contexts using the cichlid fish Astatotilapia burtoni. We find that phenotypically dominant males display behavioral traits that typify leadership across taxonomic systems - aggressive, social centrality, and movement leadership, while subordinate males are passive, socially peripheral, and have little influence over movement. However, in a more complex group-consensus task involving visual cue associations, subordinate males become the most effective agents of social change. We find that dominant males are spatially distant and have lower signal-to-noise ratios of informative behavior in the association task, potentially interfering with their ability to generate group-consensus. In contrast, subordinate males are physically close to other group members, have high signal-to-noise behaviors in the association task, and visual connectivity to other group members equal to that of dominant males. The attributes that define effective social influence are therefore highly context-specific, with socially and phenotypically dominant males being influential in routine but not complex social scenarios. These results demonstrate that behavioral traits that are typical of socially dominant individuals may actually reduce their social influence in other contexts. Significance StatementThe attributes that allow individuals to attain positions of social power and dominance are common across many vertebrate social systems - aggression, intimidation, coercion. Yet these traits are socially aversive, and can make dominant individuals poor agents of social change. In a vertebrate system (social cichlid fish) we show that dominant males are aggressive, socially central, and lead group movement. Yet dominant males are poor effectors of consensus in an more sophisticated association task compared with passive, socially-peripheral subordinate males. The most effective agents of social influence possess behavioral traits opposite of those typically found in position of social dominance, suggesting the behavioral processes that generate social dominance may simultaneously place the most ineffective leaders in positions of power.

animal behavior and cognition↗