Tadpoles rely on mechanosensory stimuli for communication when visual capabilities are poor.

The ways in which animals sense the world changes throughout development. For example, young of many species have limited visual capabilities, but still make social decisions, likely based on information gathered through other sensory modalities. Poison frog tadpoles display complex social behaviors that have been suggested to rely on vision despite a century of research indicating tadpoles have poorly-developed visual systems relative to adults.

Activity of FoxP2-positive neurons is associated with tadpole begging behavior.

Motor function is a critical aspect of social behavior in a wide range of taxa. The transcription factor FoxP2 is well studied in the context of vocal communication in humans, mice, and songbirds, but its role in regulating social behavior in other vertebrate taxa is unclear. We examined the distribution and activity of FoxP2-positive neurons in tadpoles of the mimic poison frog ().

Neural activation patterns associated with mouthbrooding, maternal care, infanticide and fry release in an African cichlid fish.

Parental care has evolved several times and is present across taxa. Parental care behaviors, such as food provisioning and protection, are critical for offspring success. However, infanticide can co-exist with parental care in the same species.

Albino tadpoles prefer dark environments compared to wild type.

Tadpoles display preferences for different environments but the sensory modalities that govern these choices are not well understood. Here, we examined light preferences and associated sensory mechanisms of albino and wild-type tadpoles. We found that albino tadpoles spent more time in darker environments compared to the wild type, although they showed no differences in overall activity.

Opsin Expression Varies with Reproductive State in the Cichlid Fish Astatotilapia burtoni.

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.

Reproductive- and Social-State Plasticity of Multiple Sensory Systems in a Cichlid Fish.

Intra- and inter-sexual communications are vital to the survival and reproductive success of animals. In species that cycle in and out of breeding or other physiological condition, sensory function can be modulated to optimize communication at crucial times. Little is known, however, about how widespread this sensory plasticity is across taxa, whether it occurs in multiple senses or both sexes within a species, and what potential modulatory substances and substrates are involved.

Galanin neuron activation in feeding, parental care, and infanticide in a mouthbrooding African cichlid fish.

Galanin is a conserved neuropeptide involved in parental care and feeding. While galanin is known to mediate parental care and infanticide in rodents, its role in parental care and feeding behaviors in other taxa, particularly fishes, remains poorly understood. Mouthbrooding is an extreme form of parental care common in fishes in which caregivers carry offspring in their buccal cavity for the duration of development, resulting in obligatory starvation.

Noise during mouthbrooding impairs maternal care behaviors and juvenile development and alters brain transcriptomes in the African cichlid fish Astatotilapia burtoni.

Anthropogenic noise has increased underwater ambient sound levels in the range in which most fishes detect and produce acoustic signals. Although the impacts of increased background noise on fish development have been studied in a variety of species, there is a paucity of information on how noise affects parental care. Mouthbrooding is an energetically costly form of parental care in which the brooding fish carries developing larvae in the buccal cavity for the duration of development.

Female reproductive state is associated with changes in distinct arginine vasotocin cell types in the preoptic area of Astatotilapia burtoni.

Nonapeptides play a crucial role in mediating reproduction, aggression, and parental care across taxa. In fishes, arginine vasotocin (AVT) expression is related to social and/or reproductive status in most male fishes studied to date, and is linked to territorial defense, paternal care, and courtship. Despite a plethora of studies examining AVT in male fishes, relatively little is known about how AVT expression varies with female reproductive state or its role in female social behaviors.

Distribution of aromatase in the brain of the African cichlid fish Astatotilapia burtoni: Aromatase expression, but not estrogen receptors, varies with female reproductive-state.

Estrogen synthesis and signaling in the brains of vertebrates has pleotropic effects ranging from neurogenesis to modulation of behaviors. The majority of studies on brain-derived estrogens focus on males, but estrogenic signaling in females likely plays important roles in regulation of reproductive cycling and social behaviors. We used females of the mouth brooding African cichlid fish, Astatotilapia burtoni, to test for reproductive state-dependent changes in estrogenic signaling capacity within microdissected brain nuclei that are important for social behaviors.

Reproductive state-dependent plasticity in the visual system of an African cichlid fish.

Visual communication is used widely across the animal kingdom to convey crucial information about an animals' identity, reproductive status, and sex. Although it is well-demonstrated that auditory and olfactory sensitivity can change with reproductive state, fewer studies have tested for plasticity in the visual system, a surprising detail since courtship and mate choice behaviors in many species are largely dependent on visual signals. Here, we tested for reproductive state-dependent plasticity in the eye of the cichlid fish Astatotilapia burtoni using behavioral, gene expression, neural activation, and electrophysiology techniques.

A Comparison of Four Presumptive Tests for the Detection of Blood on Dark Materials.

Detection of blood on dark materials is difficult for crime scene examiners so presumptive tests are used to assist. This study compared the ability of luminol, leuko crystal violet, tetramethylbenzidine, and Combur Test®E to detect whole, diluted blood (1:100) and a key-shaped blood transfer stain (1:10), on dark cotton sheeting, tea towel, socks, synthetic carpet, and car mats. Powdered bleach was used to evaluate specificity of the blood detection tests.

Expression of tachykinin3 and related reproductive markers in the brain of the African cichlid fish Astatotilapia burtoni.

Neurokinin B, encoded by the tachykinin3 gene, plays a crucial role in regulating reproduction in mammals via KNDy neurons and interaction with GnRH. Previous work in teleost fishes has focused on hypothalamic tac3 expression for its role in reproduction, but detailed studies on extra-hypothalamic tac3 expression are limited. Here, we identified two tac3 genes in the social African cichlid fish Astatotilapia burtoni, only one of which produces a functional protein containing the signature tachykinin motif.

Neural and behavioural correlates of repeated social defeat.

Dominance hierarchies are common across the animal kingdom and have important consequences for reproduction and survival. Animals of lower social status cope with repeated social defeat using proactive and reactive behaviours. However, there remains a paucity of information on how an individual's coping behaviours changes over time or what neural mechanisms are involved.

Swim bladder morphology changes with female reproductive state in the mouth-brooding African cichlid .

Mouth brooding is an extreme form of parental care in which the brooding parent carries the developing young in their buccal cavity for the duration of development. Brooding fish need to compensate for the brood weight on the anterior portion of their body. For fishes with a compartmentalized swim bladder, gas distribution between the chambers may aid in regulating buoyancy during brooding.

Reproductive and metabolic state differences in olfactory responses to amino acids in a mouth brooding African cichlid fish.

Olfaction mediates many crucial life-history behaviors such as prey detection, predator avoidance, migration and reproduction. Olfactory function can also be modulated by an animal's internal physiological and metabolic states. While this is relatively well studied in mammals, little is known about how internal state impacts olfaction in fishes, the largest and most diverse group of vertebrates.

Mechanosensory signaling as a potential mode of communication during social interactions in fishes.

Signals produced during social interactions convey crucial information about the sender's identity, quality, reproductive state and social status. Fishes can detect near-body water movements via the mechanosensory lateral line system, and this sense is used during several common fish behaviors, such as schooling, rheotaxis and predator-prey interactions. In addition, many fish behaviors, such as aggressive lateral displays and reproductive body quivers, involve fin and body motions that generate water movements that can be detected by the lateral line system of nearby fish.

Localization of glutamatergic, GABAergic, and cholinergic neurons in the brain of the African cichlid fish, Astatotilapia burtoni.

Neural communication depends on release and reception of different neurotransmitters within complex circuits that ultimately mediate basic biological functions. We mapped the distribution of glutamatergic, GABAergic, and cholinergic neurons in the brain of the African cichlid fish Astatotilapia burtoni using in situ hybridization to label vesicular glutamate transporters (vglut1, vglut2.1, vglut3), glutamate decarboxylases (gad1, gad2), and choline acetyltransferase (chat).

The Mechanosensory Lateral Line System Mediates Activation of Socially-Relevant Brain Regions during Territorial Interactions.

Animals use multiple senses during social interactions and must integrate this information in the brain to make context-dependent behavioral decisions. For fishes, the largest group of vertebrates, the mechanosensory lateral line system provides crucial hydrodynamic information for survival behaviors, but little is known about its function in social communication. Our previous work using the African cichlid fish, Astatotilapia burtoni, provided the first empirical evidence that fish use their lateral line system to detect water movements from conspecifics for mutual assessment and behavioral choices.

The mechanosensory lateral line is used to assess opponents and mediate aggressive behaviors during territorial interactions in an African cichlid fish.

Fish must integrate information from multiple sensory systems to mediate adaptive behaviors. Visual, acoustic and chemosensory cues provide contextual information during social interactions, but the role of mechanosensory signals detected by the lateral line system during aggressive behaviors is unknown. The aim of this study was first to characterize the lateral line system of the African cichlid fish Astatotilapia burtoni and second to determine the role of mechanoreception during agonistic interactions.