Integrative Organismal Biology

A broad class of animals rely on touch sensation for perception. Among insects, the American cockroach P. americana is a touch specialist that uses a pair of soft antennae with distributed sensors to touch its environment to guide decision making. During touch, forces on the antenna can activate thousands of mechanosensors. To understand the content of this sensory information, it is critical to understand how antenna mechanics shape the transmission of contact forces. Here, we investigate the mechanical behavior and morphology of the American cockroach antenna at the individual segment level through experiments, mathematical modeling, imaging with Micro-Computed Tomography (Micro-CT), 3D reconstruction of antenna morphology, and finite element modeling (FEM). Our experimental results and model predictions reveal that the antenna flagellum bends according to a kinematic chain model, with rigid segments connected by joints. Whereas the middle region of the antenna consistently fractured under cyclic bending, the tip region remained intact under large deformations, revealing mechanical specialization along the antenna. Micro-CT imaging revealed an invagination of the exocuticle at segment intersections of the tip. To test the hypothesis that this structure can enhance flexibility and robustness, we used FEM and confirmed that the invagination allows for larger bending without structural failure (buckling). Applying FEM to a morphologically accurate kinematic chain model of the flagellum revealed the relationship between the local strain at the location of marginal sensilla and intersegment angle, predicting the information available for antenna proprioception. Taken together, these findings reveal biomechanical adaptations of insect antennae and provide a critical step toward a mechanistic understanding of touch sensation in a touch specialist. SUMMARY STATEMENTBy combining experiments, imaging and modeling, we demonstrate distinct mechanical features in the cockroach antenna and provide a framework to model the neuromechanics of the antenna in an insect touch specialist.

Siphonophores are ubiquitous and often highly abundant members of pelagic ecosystems throughout the open ocean. They are unique among animal taxa in that they use multiple jets for propulsion. Little is known about kinematics of the individual jets produced by nectophores or how the jets are coordinated during normal swimming behavior. Using remotely operated vehicles and SCUBA, we video recorded the swimming behavior of several physonect species in their natural environment. The pulsed kinematics of the individual nectophores that comprise the siphonophore nectosome were quantified and, based on these kinematics, we examined the coordination of adjacent nectophores. We found for all species that nectophores sharing the same side of the nectosomal axis were coordinated metachronally. However, this coordination was not shared with nectophores on the opposite side of the nectosomal axis. For most species, the metachronal contraction waves of nectophores were initiated by the apical nectophores and traveled dorsally. However, the metachronal wave of Apolemia rubriversa traveled in the opposite direction. Although nectophore groups on opposite sides of the nectosome were not coordinated, they pulsed with similar frequencies. This enabled siphonophores to maintain relatively linear trajectories during swimming. The timing and characteristics of the metachronal coordination of pulsed jets affects how the jet wakes interact and may provide important insight into how interacting jets may be optimized for efficient propulsion.

Although ants are conceived of as paragons of social complexity, it may be their locomotory capacity that truly sets them apart from other Hymenoptera. Based on our comparative kinematic analysis of Formicidae for level, straight-line locomotion in a broad phylogenetic context, we observe that ants are distinctly capable runners. No sampled hymenopteran paralleled the body-scaled speed of ants. Relative stride lengths for ants were longer than other sampled taxa despite short ground contact durations relative to swing durations. With respect to spatial gait patterns, ants had relatively narrow hindleg and broad midleg step-widths on average, possibly enhancing speed and turning ability. Ants were able to extend their propulsive pair of legs, those of the metathorax, extremely far posterad relative to other sampled taxa, and had a distinct locomotory posture, with a high ground clearance and the femorotibial joints raised above their backs. Despite the unique modifications of their coxotrochanteral articulations, ant forelimbs were largely unremarkable with respect to our quantified variables. Sawflies, in contrast, had extremely wide and perhaps inefficient foreleg stances, and were observed for the first time to have what appears to be a dominant tetrapodal gait pattern, which raises unexpected questions about the early evolution of the Hymenoptera. Finally, we observed variability in attachment abilities and no consistent pattern of leg liftoff sequence across the sampled taxa. Our results establish locomotory evolution in the Hymenoptera as a functionally and structurally variable system with numerous directions of future research, particularly for phylogenetic comparison across wing-monomorphic and wing-polymorphic lineages. Summary statementThis work establishes a comparative phylogenetic approach to hymenopteran kinematics, demonstrating that ant locomotory capacity is derived and observes, unexpectedly, that the sampled sawflies (symphyta) never used a tripod gait.

Dogs and other members of Canidae utilize their tails for different purposes, including agile movements, such as running and jumping. In this study, we utilized motion capture biomechanical data of a border collie executing an agile rotational jump maneuver. This data created a 17-segment biomechanical model of the border collies (Canis familiaris) limb movement during agile jumps. This model was verified by comparing it to the biomechanical movement and fitting the dogs agile task with an RMSE less than 2.5%. Using this joint model, we held specific segments constant to view their inertial impact on the dog during the aerial phase of jumping. Results suggest that the tail, hind limbs, and fore limb provides little to no inertial advantage during these rotational jump maneuvers. The tail of dogs likely does have a minimal impact on inertia, the opposite of animals like the gecko. This work could alleviate unknown biomechanical use of the tails to understand the behavioral biomechanics of lesser-known species in their ability to use their tail for rapid and taxing behaviors, including sprinting or climbing.

The tail of birds contributes substantially to flight aerodynamics through lift generation, reduction of pressure drag, and pitch stabilization. Hummingbirds are powerful flyers, able to sustain hovering in still air, generate lift in both the up- and downstroke, and takeoff due to substantial developmental investment in their wings and corresponding musculature. Given the abundance of wing power, it is possible that tails are less essential to the aerodynamics of hummingbird flight than they are in other birds, freeing them for non-locomotor functions. Hummingbird tails are well known for their morphological elaboration as sexually selected ornaments, including sound generation. Our observations, and brief descriptions in the literature, led us to hypothesize that tail flaring may serve as another form of sexual signaling, used by males during male-male fighting. To test this, we used high-speed video to record agonistic encounters among seven species of hummingbird the field and found 95% of inter- and intra-sexual and specific contests included tail flaring. We measured kinematics of this flaring during male-male fighting of calliope hummingbirds (Selasphorus calliope, n = 5) indoors. Consistent with our hypothesis, captive males exhibited greater angles of tail flare when engaged in a fight (26.9 {+/-} 42.9{degrees}, mean {+/-} sd) than when performing solitary landing (-12.7 {+/-} 8.6 {degrees}) and takeoff (-11.1 {+/-} 6.6 {degrees}) maneuvers. We evaluate these results in the context of signaling during animal contests and propose future tests of whether tail flaring is an honest signal of individual quality and Resource Holding Potential (RHP). Summary StatementMale-male fighting is common in hummingbirds with competition over food and mates. During these competitions, tail flaring and waggle maneuvers are used as a signal of aggressive intent.

Cephalopods are highly versatile predators, with many species using suckers to capture their prey. These suckers attach to substrates ranging from the stiff, rough exoskeletons of crustaceans to the soft, smooth mucosal tissues of other cephalopods. Despite generating higher suction pressures than octopuses, less attention has been given to the biomechanics of cuttlefish suckers. Cuttlefish suckers exhibit a stiff, rough papillated rim that acts as a seal when in contact with a substrate. We hypothesise that these rim papillae have evolved to attach to rough substrates that match their own rugosity and to prevent the trapping of water at the contact interface, which occurs for soft interfaces underwater. To test this hypothesis, we investigated the passive attachment performance of common cuttlefish (Sepia officinalis) suckers ex vivo on a variety of artificial substrates that differed in both stiffness and roughness. We found that suckers generated larger attachment forces on stiffer substrates. Furthermore, sucker attachment forces varied significantly with substrate roughness, where highest attachment forces occurred on substrate roughnesses that coincided with the average sucker papillae size ([~]6.33 m RMS). These findings indicate that the papillae morphology may be associated with attachment performance, and could inform the design and development of versatile, bioinspired suction cups. Summary StatementCuttlefish suction cups have microscopic pillars that may interact with rough or soft surfaces to improve adhesion. We systematically examine this hypothesis using a pull-off experiment and a mathematical model.

The evolution of visual control of the hand to assist feeding by primates is uncertain but in anthropoid primates vision contributes not only to reaching for food and grasping it but also to the withdraw movement that brings food to the mouth. The strepsirrhines are a relatively large monophyletic group of Euarchontoglires near the base of the primate cladogram that are described as using vision to reach for food, but it is not known whether they use vision to assist the withdraw movement. The present study answere this question in 22 species of captive strepsirrhines from 6 of the seven strepsirrhine families, Daubentoniidae, Cheirogaleidae, Indriidae, Lemuridae, Lorisidae and Galagidae. Animals were videorecorded as they ate their normal food provisions. Dependent measures for analyses were ground withdraw movements, bringing grasped food to the mouth, and inhand withdraw movements, brining food held in the hand to the mouth, as well as the posture and head movements associated with each type of withdraw. Frame-by-frame scores from the video record showed that there were large differences between and within strepsirrhine families in these movements. Nevertheless, for all species, the withdraw movement was mediated by somatosensation, with mouth reaching and perioral contact with food determining how food was eventually eaten. Nonvisual behavior also contributed to food grasping as many species sniffed food before or during grasping. Even amongst species that made most use of the hand for their withdraws, the insectivores Loris lydekkerianus and Galago senegalensis, and herbivores, Hapalemur simus and Eulemur flavifrons, perioral contact was used to orient food for biting. The use of somatosensation and the absence of vision in mediating getting food in strepsirrhines suggests that visual mediation of the withdraw is an anthropoid innovation.

Ctenophores are a group of largely-planktonic, gelatinous carnivores whose most common method of prey capture is nearly a phylum-defining trait. Tentaculate ctenophores release an unknown proteinaceous adhesive from specialised colloblast cells lining their tentacles following prey contact with the tentacles. There exist no extant studies of the mechanical properties of colloblast adhesive. We use live microscopy techniques to visualise adhesion events between Pleurobrachia pileus colloblasts and probes of different surface chemistries in response to probing with varying contact areas. We further define two mechanisms of adhesion termination upon probe retraction. Adapting a technique for measuring surface tension, we examine the adhesive strength of tentacles in the ctenophore Pleurobrachia bachei under varying pH and bonding time conditions, and demonstrate the destructive exhaustion of colloblast adhesive release. We find that colloblast-mediated adhesion is rapid, and that the bonding process is robust against shifts in ambient pH. However, we find that the Pleurobrachia colloblast adhesive system is among the weakest biological adhesive systems yet described. We place this surprising observation into a broader ecophysiological context by modeling prey capture for prey of a range of sizes. We find that limited use of colloblast adhesive with high surface area contact is suitable both for capturing appropriately sized prey and rejecting, by detachment, prey above a certain size threshold. This allows Pleurobrachia, lacking a mechanism to directly "see" potential prey they are interacting with, to invest in capturing only prey of an appropriate size, decreasing the risk of injury. Summary statementCtenophore colloblast adhesive is found to be strong, but few colloblasts are simultaneously active, producing a weakly-adhering system. A physical model demonstrates how such a system may filter unsuitable prey.

Centimeter-scale fliers that combine wings with springy elements must contend with the high power requirements and mechanical constraints of flapping wing flight. Insects utilize elastic energy exchange to reduce the inertial costs of flapping wing flight and potentially match wingbeat frequencies to a mechanical resonance. Flying at resonance may be energetically favorable under steady conditions, but it is difficult to modulate the frequency of a resonant system. Evidence suggests that insects utilize frequency modulation over long time scales to adjust aerodynamic forces, but it remains an open question the extent to which insects can modulate frequency on the wingstroke-to-wingstroke timescale. If wingbeat frequencies deviate from resonance, the musculature must work against the elastic flight system, thereby potentially increasing energetic costs. To assess how insects address the simultaneous needs for power and control, we tested the capacity for wingstroke-to-wingstroke wingbeat frequency modulation by perturbing free hovering Manduca sexta with vortex rings while recording high-speed video at 2000 fps. Because hawkmoth flight muscles are synchronous, there is at least the potential for the nervous system to modulate frequency on each wingstroke. We observed {+/-} 16% wingbeat frequency modulation in just a few wing strokes. Via instantaneous phase analysis of wing kinematics, we found that over 85% of perturbation responses required active changes in motor input frequency. Unlike their robotic counterparts that explicitly abdicate frequency modulation in favor of energy efficiency, we find that wingstroke-to-wingstroke frequency modulation is an underappreciated control strategies that complements other strategies for maneuverability and stability in insect flight.

The trade-offs of group living are modulated by the phenotypes of individual members of a social group, particularly in dynamic and diverse habitats like coral reefs. Little is known about the patterns of physiological traits among fishes within social groups and the mechanisms that promote these patterns, which could elucidate the drivers of group composition and their downstream ecological and evolutionary impacts. Here, in the gregarious damselfish species Chromic viridis, we examined inter-group differences in whole-animal physiological traits and the tendency for fish to move either within sites (i.e., sections of continuous reef) or among habitats (i.e., reefs separated by sandy substratum) to a new social group. Using oxygen uptake as a proxy for aerobic metabolic rate, we found significant differences in maximum metabolic rate (MMR) and aerobic scope (AS) among schools from different habitats, with these traits higher in habitats with faster water flow rates. However, we found no differences in any metabolic traits (standard metabolic rate, SMR, MMR, AS) between groups from the same site. These trends could stem from a range of mechanisms, as mark-recapture studies of this species indicated a willingness to migrate to a new social group in over 30% of recollected fish. However, there were no effects of either body size or perceived habitat risk on the distance moved or movement type (i.e., over coral or sand). Our results indicate that, in social species, a combination of mechanisms may influence phenotypic differences among groups over different spatial scales.

In many species, males possess specialized weaponry that have evolved to confer a benefit during aggressive interactions. Because male weaponry is typically an exaggerated or extreme version of pre-existing body parts, females often possess reduced or weaponry. Although much research has investigated sexual dimorphism in the sizes of such weapons, other weapon components, such as weapon performance or alternative weapon forms can also explain the evolution of weapon sexual dimorphisms. Here, we investigated the allometry and variation of multiple weapon components of hindleg weaponry in the male and female giant mesquite bugs, Thasus necalifornicus. Despite theory predicating greater allocation in male weaponry, we found that females allocated more into the lengths of their hindlegs compared to males. Despite this allocation, males possess relatively wider hindlegs, which likely increase area of muscle mass. Indeed, the squeezing performance of male hindlegs was much greater than that of female hindlegs. Lastly, we also described the allometry and variation in a male weapon component, prominent tibial spines, which likely are used to damage competitors during aggressive interaction. Overall, our findings highlight the intricacies of weapon sexual dimorphism and demonstrate the importance of measuring multiple weapon components and not a single measure.

Analyses of vertebrate locomotion have frequently revealed variations in locomotor energetics and movement both among individuals and through time within an individual. This variation is often collapsed into mean values for broad comparative analyses of function. However, kinematic patterns of locomotion, even when animals move at a near-constant mean speed, frequently vary with both the physical and biological context. Here we demonstrate, using analyses of fish locomotion and energetics, how variation among individuals in kinematic gaits can manifest as changes in dynamics of metabolic rate (estimated from oxygen uptake). We present kinematic data from a small school of giant danio (Devario aequipinnatus) to show that fish within a school frequently modulate their kinematics and change position, even when the school moves at an overall constant mean speed. We show that rainbow trout (Oncorhynchus mykiss), swimming over a range of speeds, exhibit considerable variation in tail beat frequency and metabolic rate among speeds. By experimentally altering the fluid dynamic environment, we demonstrate that brook trout (Salvelinus fontinalis) show correlated modulation of both kinematics and metabolic rate. Simultaneous measurement of energetic and biomechanical characteristics can unveil the physiological, biomechanical, and fluid dynamic mechanisms that underlie dynamic changes in vertebrate locomotor gaits.

Many animals assume characteristic postures when resting or sleeping. These postures are often stable and can be maintained passively, thus reducing the energy cost for maintaining an unstable posture. For example, many tetrapods lay prone on the ground and some negatively buoyant fishes are also able to rest on the substrate. Other fishes rest suspended in the water column. Counterintuitively, hovering this way can be of similar energetic cost to swimming. Even if the fish is perfectly neutrally buoyant, any displacement between its center of mass and center of buoyancy will produce destabilizing pitching torques that the fish must constantly work to counteract if they wish to maintain that posture. We hypothesized that a neutrally buoyant fish could rest at an equilibrium - a posture at which no destabilizing torques are produced by the body --to minimize the metabolic costs associated with hovering. Specifically, we studied the bluegill sunfish (Lepomis macrochirus), which is unstable in a horizontal posture. However, by pitching their bodies up or down they may be able to attain a less costly equilibrium posture, one which vertically aligns their center of mass and center of buoyancy. To test this hypothesis, we measured pitch angle of bluegill over the course of 24 hours. We also measured the pitch angles of the body that correspond to stable and unstable equilibria. We found that the stable equilibrium was a belly-up posture, and the unstable equilibrium is a dorsal side up posture pitched 53{+/-}26{degrees} head-down. The fish rested at a head-down pitch of -10.7{+/-}0.4{degrees} degrees, which is significantly steeper than the average pitch during the day of -3.4{+/-}0.8{degrees} degrees head down. These results show that bluegill do not rest at unstable or stable equilibrium. However, they do rest closer to unstable equilibrium at night than during the day. This may allow them to decrease destabilizing torques generated from the relative locations of the COM and COB while maintaining maneuverability.

Collisions with buildings are a major source of mortality for wild birds, but these instantaneous events are difficult to observe. As a result, the mechanistic causes of collision mortality are poorly understood. Here, we evaluate whether sensory and biomechanical traits can explain why some species are more collision-prone than others. We first examined concordance of species vulnerability estimates across previous North American studies to determine whether these estimates are repeatable, and whether vulnerability is more similar among closely-related species. We found moderate concordance and phylogenetic signal, indicating that some bird species are consistently more collision-prone than others. We next tested whether morphological traits related to flight performance and sensory guidance explain these differences among species. Our comparative analysis shows that two traits primarily predict collision vulnerability within passerines: relative beak length and relative wing length. Small passerine species with relatively short wings and those with relatively long beaks are more collision-prone, suggesting that greater maneuverability and obstructed vision contribute to risk. Together, these findings can help inform mitigation strategies and predict which species will be most at risk in other regions.

In birds, the quadrate bone serves as a hinge articulating with the lower jaw and the skull, playing an important mechanical role in the feeding apparatus. Avian cranial kinesis is dependent on the streptostylic quadrate transferring force from the adductor muscles at the back of the skull toward the beak, as part of a four-bar mechanical linkage to elevate and depress the bill. The complex morphology of the bird quadrate has led to authors adopting a range of alternative terminologies to describe the same anatomical structures and character states, impeding clarity of communication and presenting a barrier to progress in our understanding of the evolution of this important component of the avian feeding apparatus. Here, we reconcile terminological discord among previous studies on avian quadrate morphology and propose a stable nomenclature for future work. To characterise the considerable variation in quadrate form across crown bird diversity, we present an extensive anatomical atlas of the avian quadrate and summarise major patterns of quadrate morphological variation across extant avian phylogeny. In addition, we investigate macroevolutionary patterns in avian quadrate morphology, incorporating comparisons of crown birds and Late Cretaceous near-crown stem birds. We demonstrate that quadrate characters are useful for diagnosing a range of major avian subclades, and suggest that numerous distinctive features are likely to be associated with important biomechanical consequences. This investigation has implications for resolving the unsettled phylogenetic relationships of extinct bird clades such as Pelagornithidae and Gastornithiformes, as well as controversial relationships within several extant groups.

We evaluated subtle-to-incipient pathology traits in coxofemoral joints from dry bone museum specimens of: Vulpes lagopus; Vulpes; Nyctereutes procyonoides; Urocyon cinereoargenteus; Canis lupus familiaris; and Canis latrans. Multiple intra-articular structures were evaluated on acetabula and proximal femora. Primary observations included multifocal, variable osteophytelike formations; osteophyte-like rimming of articular margins and femoral head (ligamentum teres attachment); and rough or worn bone. Within limitations on valid statistical applications, we observed little difference among the high trait frequencies across taxa, aligning with previous morphological observations. Additionally, for this study, we evaluated the known history of the taxa, from deep time to the present, to consider our data in a phylogenetic context. Potential introgression over the evolution of Canidae, along with early history of the canid genome, likely supported broad and deep conservation of pathophysiological processes associated with observable pathology at the same intra-articular foci, across taxa. We also evaluated the "modern" natural histories of the taxa, noting that coxofemoral joint impacts of their respective life habits did not appear to influence pathology trait outcomes differentially. We conclude that conservation of the physiology underlying subtle and incipient coxofemoral joint pathology that did not segregate among taxa. We hypothesize that the intersecting basic biology of growth-development and insult response, over long geological time, may owe in part to the evidently long histories of hybridization and generally high historical gene flow, with high levels of heterogeneity. These data argue for new research to advance an interdisciplinary, integrated understanding of relationships among canid growth-development, incipient-to-subtle joint pathology, influences of natural histories across related taxa, and implications for genomic interrelationships.

The fins of fishes are remarkably diverse, and this variation is tied to the ecology and locomotor mode of a species. While numerous genetic factors are known to pattern fins in development, it is unclear how developmental plasticity shapes the fin skeleton. Here, we analyze the cichlid Satanoperca daemon, raised under three distinct feeding regimes, and show that plasticity is pervasive across the pectoral fin skeleton with foraging mode impacting patterning of both the endoskeleton and dermal skeleton. Radials and fin rays were {micro}CT scanned and analyzed using a combination of linear measures and geometric morphometrics. Anteroposterior patterning of both radials and fin rays are affected by feeding regime. Notably, S. daemon pectoral fin rays show distinct patterns of fin ray branching between treatments, suggesting altered fin stiffness. We argue that the observed changes in the fin likely reflect developmental plasticity resultant from altered swimming behaviors when fishes are challenged to forage in different ways. These data show how non-genetic mechanisms can shape both the endoskeleton and dermal skeleton of fins, and that foraging mode can induce plastic changes in skeletal elements that do not directly interface with food items.

The arachnid order Schizomida is a relatively understudied group of soil-dwelling predators found on all continents except Antarctica. While efforts to understand their biology are growing, there is still much to know about them. A curious aspect of their morphology is the male flagellum, a sexually dimorphic, tail-like structure which differs in shape across the order and functions in their courtship rituals. The flagellar shape is important for taxonomic classification, yet few efforts have been made to examine shape diversity across the group. Using elliptical Fourier analysis, a type of geometric morphometrics based on outline shape, we quantified shape differences across a combined nearly 550 outlines in the dorsal and lateral views, categorizing them based on genus, family, biogeographic realm, and habitat, with special emphasis on Caribbean and Cuban fauna. We tested for allometric relationships, differences in disparity based on locations and sizes in morphospace among these categories, and for clusters of shapes in morphospace. We found multiple differences in all categories despite apparent overlaps in morphospace, evolutionary allometry, and evidence for discrete clusters in some flagellum shapes. This study can serve as a foundation for further study on the evolution, diversification, and taxonomic utility of the male flagellum.

Avian haemosporidia are blood parasites that can have dramatic fitness consequences on their hosts, including largescale population declines when introduced to naive hosts. Yet the physiological effects that accompany haemosporidian infection and underlie these fitness decrements are poorly characterized in most wild birds. Because haemosporidia destroy host red blood cells and consume host hemoglobin, they are predicted to have detrimental impacts on avian blood-oxygen transport and, as a result, reduce aerobic performance. However, the documented effects of infection on avian hematological traits vary across species and no effects have been demonstrated on avian aerobic performance to date. Here we quantified the physiological effects of haemosporidian infections on wild Pink-sided Juncos (Junco hyemalis mearnsi) breeding in northwestern Wyoming, USA. We assayed hematological traits (hemoglobin concentration and hematocrit) and aerobic performance (resting and summit metabolic rates, thermogenic endurance, and aerobic scope), then screened individuals for haemosporidian infection post-hoc (n = 106 adult juncos). We found that infection status did not correlate with any of the physiological indices that we measured, suggesting there is little cost of haemosporidian infection on either junco aerobic performance or energy budgets. Our results highlight the need for more studies of haemosporidia infections in a broader range of species and in a wider array of environmental contexts.

The relationship between morphology and ecology is mediated by behavior. We explore this relationship by assessing the link between trophic ecology and the use of prey-specific feeding behaviors in a cichlid fish system. Cichlid diversification features repeated transitions between free-moving prey and attached benthic prey, requiring predators to evolve prey-specific approaches to feeding. Using 2000 Hz video, we characterized feeding behavior on an experimental attached benthic prey in seven species of Mesoamerican heroine cichlid spanning three independent transitions to specialized piscivory and two to specialized benthic-feeding ecology. We investigated the effect of feeding ecology on the behavior and kinematics of benthic grazing, a derived, specialized mode of cichlid feeding. Surprisingly, all species readily fed on benthic prey, regardless of their feeding ecology. Nearly all non-benthic species used the same benthic-feeding behaviors as ecological benthic-feeders. Our findings demonstrate an unexpected level of behavioral versatility among cichlid species in exploiting functionally demanding prey outside their typical diets. We propose that this repertoire of latent feeding behaviors supports trophic versatility and facilitates niche diversification. We also show that two benthic-feeding lineages of Neotropical cichlids evolved distinct approaches to benthic feeding, exhibiting the highest and lowest total feeding-strike kinesis, respectively. Together, our findings highlight the importance of behavior in linking morphology and ecology and motivate further study into the diversity and evolutionary context of benthic feeding across the Cichlidae. SUMMARY STATEMENTWe demonstrate that prey-specific feeding behaviors and strike kinematics vary with trophic ecology in heroine cichlids and discuss the potential role of latent feeding behaviors in trophic diversification.