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Introduction
Comparative biomechanics and biomaterials. 3 -D visualization and material analysis. I work at a marine lab with cutting edge equipment 10 meters from the sea. Looking for bioinspired designs and materials.
Current institution
Additional affiliations
August 2009 - present
June 1999 - August 2001
July 1993 - May 1999
Education
September 1993 - May 1999
September 1989 - May 1991
September 1982 - May 1986
Publications
Publications (289)
The morphology of a skeletal structure is driven in part by the forces it endures over evolutionary time. We demonstrate that generative design, an iterative engineering tool, can yield insight into the loading regimes of complex skeletal elements. With only a simple model of the spatial constraints and potential forces seen by a skeletal element,...
Frugivorous vertebrates engage in a mutualism with fruiting plants: the former receive a nutrient subsidy, and the latter benefit by having their seeds dispersed far from parent plants. Vertebrate frugivores like primates and bats have particular morphologies suited for gripping fruit and then pulverizing fruit soft tissues; however, variation amon...
Otodus megalodon (Lamniformes: Otodontidae) is an iconic Neogene shark, but the lack of well-preserved skeletons has hampered our understanding of various aspects of its biology. Here, we reassess some of its biological properties using a new approach, based on known vertebral specimens of O. megalodon and 165 species of extinct and extant neoselac...
Anthropogenic noise is a pervasive environmental pollutant that continues to expand and increase globally, especially in marine environments, affecting many marine animals, especially fish. Although interest and concern regarding the effects of noise on fish has increased, most studies still focus on the effects noise has on individual species, oft...
A new genus and four new species of clingfishes are described based on specimens collected primarily from seagrass along the southern coast of Australia. The new genus Melanophorichthys is distinguished from all other genera of the Gobiesocidae by aspects of colour pattern, including the presence of numerous, large, dark brown to black melanophores...
Frugivorous vertebrates engage in a mutualism with fruiting plants: the former receive a nutrient subsidy and the latter benefit by having their seeds distributed far from parent plants. Vertebrate frugivores like primates and bats have particular morphologies, like wide jaws and blunt teeth, which are thought to aid in dismantling fruit and obtain...
Armour has been present in vertebrates for millions of years and has evolved independently several times in the ray finned fishes. While armour is typically considered defensive, it is a multifunctional trait with many plausible alternative functions. We explore the hydrodynamic function of armour in nine species of poachers (Agonidae) by visualizi...
Invasions of freshwater habitats by marine fishes provide exceptional cases of habitat-driven biological diversification. Freshwater habitats make up less than 1% of aquatic habitats but contain ∼50% of fish species. However, while the dominant group of freshwater fishes (Otophysi) is older than that of most marine fishes (Percomorphaceae), it is l...
Rhinolepadichthys, a new genus of the gobiesocid subfamily Diademichthyinae, is described for the “Lepadichthys” lineatus complex (including Rhinolepadichthys geminuscomb. nov., R. heemstraorumcomb. nov., R. lineatuscomb. nov., and R. polyastrouscomb. nov.). Detailed investigation of external morphology and osteological anatomy of the new genus and...
The impact of preserved museum specimens is transforming and increasing by three-dimensional (3D) imaging that creates high-fidelity online digital specimens. Through examples from the openVertebrate (oVert) Thematic Collections Network, we describe how we created a digitization community dedicated to the shared vision of making 3D data of specimen...
The megatooth shark, †Otodus megalodon, which likely reached at least 15 m in
total length, is an iconic extinct shark represented primarily by its gigantic teeth in the
Neogene fossil record. As one of the largest marine carnivores to ever exist, under�standing the biology, evolution, and extinction of †O. megalodon is important because
it had a s...
Natural history museums are vital repositories of specimens, samples and data that inform about the natural world; this Formal Comment revisits a Perspective that advocated for the adoption of compassionate collection practices, querying whether it will ever be possible to completely do away with whole animal specimen collection.
The mechanics of water entry has been investigated extensively for rigid and deformable media, for a wide range of engineering applications. Limited attention has been paid to understanding the water entry process of structural systems with both rigid and deformable components. Inspired by diving animals such as the gannet, the paper experimentally...
Synopsis
Armor is a multipurpose set of structures that has evolved independently at least 30 times in fishes. In addition to providing protection, armor can manipulate flow, increase camouflage, and be sexually dimorphic. There are potential tradeoffs in armor function: increased impact resistance may come at the cost of maneuvering ability; and o...
Synopsis
The increased use of imaging technology in biological research has drastically altered morphological studies in recent decades and allowed for the preservation of important collection specimens alongside detailed visualization of bony and soft-tissue structures. Despite the benefits associated with these newer imaging techniques, there rem...
From dissuading predators to gaining an edge on intraspecific rivals, animals have evolved weapons to meet various needs. Those with the most extreme weapons often use them to battle conspecifics, but some weapons defend against predation and others signal prowess to prospective mates and rivals. Many fishes have evolved armaments, but humans rarel...
Filter‐feeding has been present for hundreds of millions of years, independently evolving in aquatic vertebrates’ numerous times. Mysticete whales are a group of gigantic, marine filter‐feeders that are defined by their fringed baleen and are divided into two groups: balaenids and rorquals. Recent studies have shown that balaenids likely feed using...
The coastal waters of the North Pacific are home to the Northern clingfish (Gobiesox maeandricus), Pacific spiny lumpsucker (Eumicrotremus orbis), and marbled snailfish (Liparis dennyi) - three fishes that have evolved ventral adhesive discs. Clingfish adhesive performance has been studied extensively, but relatively little is known about the perfo...
Synopsis
Extreme abiotic factors in deep-sea environments, such as near-freezing temperatures, low light, and high hydrostatic pressure, drive the evolution of adaptations that allow organisms to survive under these conditions. Pelagic and benthopelagic fishes that have invaded the deep sea face physiological challenges from increased compression o...
Complex prey processing requires the repositioning of food between the teeth, as modulated by a soft tissue appendage like a tongue or lips. In this study, we trace the evolution of lips and ligaments, which are used during prey capture and prey processing in an herbivorous group of fishes. Pacus (Serrasalmidae) are Neotropical freshwater fishes th...
Elasmobranch fishes (sharks, skates and rays) consume prey of a variety of sizes and properties, and the feeding mechanism typically reflects diet. Spotted ratfish, Hydrolagus colliei (Holocephali, sister group of elasmobranchs), consume both hard and soft prey; however, the morphology of the jaws does not reflect the characteristics typical of dur...
Small organisms use propulsive springs rather than muscles to repeatedly actuate high acceleration movements, even when constrained to tiny displacements and limited by inertial forces. Through integration of a large kinematic dataset, measurements of elastic recoil, energetic math modeling and dynamic math modeling, we tested how trap-jaw ants (Od...
Skates are a diverse group of dorso-ventrally compressed cartilaginous fishes found primarily in high-latitude seas. These slow-growing oviparous fishes deposit their fertilized eggs into cases, which then rest on the seafloor. Developing skates remain in their cases for 1-4 years after they are deposited, meaning the abiotic characteristics of the...
Joining the ranks of vertebrates that glow is the Pacific Spiny Lumpsucker, Eumicrotremus orbis, a subtidal species widely distributed across the North Pacific Ocean. Aside from their charismatic appearance, the Pacific Spiny Lumpsucker is known for its ventral suction disc that is used to stick to substrates amid changing currents and tides. Here...
Ghost electric knifefishes (Gymnotiformes: Apteronotidae) are a dominant component of the species diversity and biomass of large lowland rivers in Greater Amazonia, including 77 species that exhibit diverse craniofacial morphologies associated with trophic and secondary sexual traits. Here we use open-source computed micro-tomography (CT) scans to...
The Northern clingfish (Gobiesox maeandricus) has a suction-based adhesive disc that can stick to incredibly rough surfaces, a challenge for stiff commercial suction cups. Both clingfish discs and bioinspired suction cups have stiff cores but flexible edges that can deform to overcome surface irregularities. Compliant surfaces are common in nature...
Synopsis:
Archerfishes (Toxotidae) are variously found in the fresh- and brackish-water environments of Asia Pacific and are well known for their ability to shoot water at terrestrial prey. These shots of water are intended to strike their prey and cause it to fall into the water for capture and consumption. While this behavior is well known, ther...
Synopsis
Second moment of area is a measure of how well the cross-section of a beam will resist bending because of its shape. Many have used second moment of area to investigate the mechanical adaptations of biological structures from stingray jaws to animal limb bones. In this context it is important to acknowledge the assumptions of beam theory,...
Actin is a fundamental member of an ancient superfamily of structural intracellular proteins and plays a crucial role in cytoskeleton dynamics, ciliogenesis, phagocytosis, and force generation in both prokaryotes and eukaryotes. It is shown that actin has another function in metazoans: patterning biosilica deposition, a role that has spanned over 5...
The northern Adriatic continental shelf hosts several coralligenous reefs rising from the sedimentary bottom and characterized by three main benthic assemblages, respectively, dominated by algal turfs, encrusting calcareous rhodophyte (ECRs) or erect sponges. Bioconstruction and bioerosion processes have been investigated using recruitment traverti...
A revised diagnosis is provided for the poorly known clingfish genus Lepadicyathus Prokofiev 2005. The genus belongs to Diademichthyinae (sensu Conway et al.) and is characterized by the following combination of characters: snout moderate in length, slightly pointed in lateral view; oral cleft very small, restricted to anterior tip of snout, poster...
The COVID-19 pandemic shut down undergraduate research programs across the United
States. A group of 23 colleges, universities, and research institutes hosted remote undergraduate research programs in the life sciences during Summer 2020. Given the unprecedented offering of remote programs, we carried out a study to describe and evaluate
them. Usin...
Predation, combat, and the slings and arrows of an abrasive and high impact environment, represent just some of the biotic and abiotic stressors that fishes are armored against. The Pacific Spiny Lumpsucker (Eumicrotremus orbis) found in the subtidal of the Northern Pacific Ocean is a rotund fish covered with epidermal, cone-shaped, enamel odontode...
Erdmannichthys, a new genus of the family Gobiesocidae, is introduced to include a species previously assigned to Aspasmichthys. This act is supported by morphological characters and the results of a recent molecular phylogenetic study that placed the two currently described species of Aspasmichthys as distant relatives within the subfamily Diademi...
Tooth replacement rates of polyphyodont cartilaginous and bony fishes are hard to determine because of a lack of obvious patterning and maintaining specimens long enough to observe replacement. Pulse-chase is a fluorescent technique that differentially colours developing mineralized tissue. We present in situ tooth replacement rate and position dat...
The morphometrics of fish otoliths have been commonly used to investigate population structures and the environmental impacts on ontogeny. These studies can require hundreds if not thousands of otoliths to be collected and processed. Processing these otoliths takes up valuable time, money, and resources that can be saved by automation. These struct...
Looking to nature for inspiration has led to many diverse technological advances. The spiral valve intestine of sharks has provided the opportunity to observe the efficiency of different valve systems. It is supposed that the spiral intestine present in sharks, skates and rays slows the transit rate of digesta through the gut and provides increased...
Large‐scale digitization projects such as #ScanAllFishes and oVert are generating high‐resolution microCT scans of vertebrates by the thousands. Data from these projects are shared with the community using aggregate 3D specimen repositories like MorphoSource through various open licenses. We anticipate an explosion of quantitative research in organ...
Synopsis
Scientific culture and structure organize biological sciences in many ways. We make choices concerning the systems and questions we study. Our research then amplifies these choices into factors that influence the directions of future research by shaping our hypotheses, data analyses, interpretation, publication venues, and dissemination vi...
We modeled swimming kinematics and body mechanics of several fish species of varying habitat and body shape based on measurements of internal vertebral morphology.
Synopsis
One key evolutionary innovation that separates vertebrates from invertebrates is the notochord, a central element that provides the stiffness needed for powerful movements. Lat...
A broad diversity of biological organisms and systems interact with soil in ways that facilitate their growth and survival. These interactions are made possible by strategies that enable organisms to accomplish functions that can be analogous to those required in geotechnical engineering systems. Examples include anchorage in soft and weak ground,...
The COVID-19 pandemic shut down undergraduate research programs across the U.S. Twenty-three sites offered remote undergraduate research programs in the life sciences during summer 2020. Given the unprecedented offering of remote research experiences, we carried out a study to describe and evaluate these programs. Using structured templates, we doc...
We tested the hypothesis that deep-sea fishes have poorly mineralized bone relative to shallower-dwelling species using data from a single family that spans a large depth range. The family Liparidae (snailfishes, Cottiformes) has representatives across the entire habitable depth range for bony fishes (0 m–> 8000 m), making them an ideal model for s...
Gobiesocidae are a moderate-sized family (currently 182 species, 51 genera) of predominantly coastal marine fishes, commonly referred to as clingfishes. Depending on the classification adopted, the species and genera of clingfishes are organized either across ten subfamilies, based on a classification scheme introduced in the 1950s (“traditional” c...
Large scale digitization projects such as #ScanAllFishes and oVert are generating high-resolution microCT scans of vertebrates by the thousands. Data from these projects are shared with the community using aggregate 3D specimen repositories like MorphoSource through various open licenses. MorphoSource currently hosts tens of thousands of 3D scans o...
The cory catfishes (Callichthyidae) are small, South American armored catfishes with a series of dermal scutes that run the length of the fish from posterior to the parieto-supraoccipital down to the caudal peduncle. In this study, we explore the anatomy and functional performance of the armored scutes in the three-striped cory catfish, Corydoras t...
Vertebrate dentitions are often collapsed into a few discrete categories, obscuring both potentially important functional differences between them and insight into their evolution. The terms homodonty and heterodonty typically conflate tooth morphology with tooth function, and require context-dependent subcategories to take on any specific meaning....
Biological armours are potent model systems for understanding the complex series of competing demands on protective exoskeletons; after all, armoured organisms are the product of millions of years of refined engineering under the harshest conditions. Fishes are no strangers to armour, with various types of armour plating common to the 400-500 Myr o...
Acanthemblemaria aceroi new species is described from the upwelling region of the Caribbean coasts of Venezuela and Colombia. It differs from its closest relative, Acanthemblemaria rivasi Stephens, 1970, known from Panama and Costa Rica, in the posterior extent of the infraorbitals, details of head spination, and unique COI sequences. The descripti...
Many vertebrates are armored over all or part of their body. The armor may serve several functional roles including defense, offense, visual display, and signal of experience/capability. Different roles imply different tradeoffs; for example, defensive armor usually trades resistance to attack for maneuverability. The poachers (Agonidae), 47 specie...
Teeth tell the tale of interactions between predator and prey. If a dental battery is made up of teeth that look similar, they are morphologically homodont, but if there is an unspecified amount of regional specialization in size or shape, they are morphologically heterodont. These are vague terms with no useful functional implication because morph...
Teeth are a model system for integrating developmental genomics, functional morphology, and evolution. We are at the cusp of being able to address many open issues in comparative tooth biology, and we outline several of these newly tractable and exciting research directions. Like never before, technological advances and methodological approaches ar...
Synopsis
The decreasing cost of acquiring computed tomographic (CT) data has fueled a global effort to digitize the anatomy of museum specimens. This effort has produced a wealth of open access digital three-dimensional (3D) models of anatomy available to anyone with access to the Internet. The potential applications of these data are broad, rangin...
The Goal: We have discussed the theme of reintegrating biology several times at the national level over several decades (ex. A New Biology for the 21st Century, National Academy of Sciences, 2009). While these discussions are fruitful and certainly the topic may require an adaptive framework, we suggest a fundamental change in how the scientific co...
The king‐of‐the‐salmon, Trachipterus altivelis (Lampriformes), has an unusual set of oral jaws which allow it the ability to protrude the entire upper jaw, containing the premaxilla and the maxilla bones, to extreme distances. Here, we provide a short description of the cranial anatomy and mechanism of jaw protrusion in T. altivelis using hand‐draw...
Fabrication of biomimetic materials and scaffolds is usually a micro- or even nanoscale process; however, most testing and all manufacturing require larger-scale synthesis of nanoscale features. Here, we propose the utilization of naturally prefabricated three-dimensional (3D) spongin scaffolds that preserve molecular detail across centimeter-scale...
Synopsis
Evolutionary transitions between habitats have been catalysts for some of the most stunning examples of adaptive diversification, with novel niches and new resources providing ecological opportunity for such radiations. In aquatic animals, transitions from saltwater to freshwater habitats are rare, but occur often enough that in the Neotro...
While artificial suction cups only attach well to smooth surfaces, the Northern clingfish can attach to surfaces ranging from nanoscale smooth to rough stone. This ability is highly desirable for technical applications. The morphology of the fish's suction disc and its ability to attach to rough and slimy surfaces have been described before, and he...
Tooth replacement in piranhas is unusual: all teeth on one side of the head are lost as a unit, then replaced simultaneously. We used histology and microCT to examine tooth-replacement modes across carnivorous piranhas and their herbivorous pacu cousins (Serrasalmidae) and then mapped replacement patterns onto a molecular phylogeny. Pacu teeth deve...
A description of the processes involved in micro-CT scanning fish specimens and processing the resulting scan data for use in research, education, and outreach.
Herbivorous fishes feed on stems, leaves, flowers, seeds, fruits, and nuts of diverse aquatic plants, as well as algae. Pacus are the herbivorous cousins of piranhas and consume a myriad of diets comprised of these plant products, but a few species are phytophages, herbivores that feed almost exclusively on rapids-dwelling (rheophilic) riverweed pl...
A new genus and two new species of miniature clingfishes are described based on specimens collected from dense stands of macroalgae in intertidal and shallow subtidal areas along the coast of southern Australia. The new genus, Barryichthys, is distinguished from other genera of the Gobiesocidae by unique features of the adhesive disc, including elo...
Batoids (skates and stingrays), exhibit swimming modes that can be characterized on a spectrum from undulation (>1 wave present along the fin) to oscillation (<0.5 wave present along the fin). The latter is a derived mode of locomotion that characterizes a group of charismatic pelagic batoids, the Myliobatidae (manta rays, cownose rays, eagle rays)...
If an animal’s body shape is specialized in a way that aids feeding on specific organisms, does this restrict what the animal can prey on? An observation of fishes feeding in the wild might now help to settle this question. Body adaptations to target specific prey don’t restrict what cichlids eat. A Petrochromis polyodon fish
Suction feeding and gill ventilation in teleosts are functionally coupled, meaning that there is an overlap in the structures involved with both functions. Functional coupling is one type of morphological integration, a term that broadly refers to any covariation, correlation, or coordination among structures. Suction feeding and gill ventilation e...
The ScanAllFish project is a large-scale effort to scan all the world's 33,100 known species of fishes. It has already generated thousands of volumetric CT scans of fish species which are available on open access platforms such as the Open Science Framework. To achieve a scanning rate required for a project of this magnitude, many specimens are gro...
Durophagous predators consume hard‐shelled prey such as bivalves, gastropods, and large crustaceans, typically by crushing the mineralized exoskeleton. This is costly from the point of view of the bite forces involved, handling times, and the stresses inflicted on the predator's skeleton. It is not uncommon for durophagous taxa to display an ontoge...
Structural and functional properties of exoskeleton in moulting sea slaters Ligia pallasii from the Eastern Pacific coast were investigated with CT scanning and electron microscopy. Ultrastructure of preecdysial and postecdysial cuticular layers was described in premoult, intramoult and postmoult animals. Cuticle is a flexible extracellular matrix...
The serrasalmids: piranhas, pacus, and their relatives, are ubiquitous Neotropical fishes with diverse diets, ecologies, and behaviors. Serrasalmids have a bony, serrated keel which lines the underbellies of these fishes, the structure for which the family is named. We examined the diversity and structure of the keel in piranhas and allies using mi...
Flexorincus , new genus and species, is described from 15 specimens (14.0–27.2 mm SL) collected from shallow (0–9 meters) intertidal and sub-tidal waters of the Rangitāhua Kermadec Islands, New Zealand. The new taxon is distinguished from all other members of the Gobiesocidae by a combination of characters, including a heterodont dentition comprisi...
Flatfishes use cyclic body undulations to force water into the sediment and fluidize substrate particles, displacing them into the water column. When water velocity decreases, suspended particles settle back onto the fish, hiding it from view. Burial may become more challenging as flatfishes grow because the area to be covered increases exponential...
Video-based observations of voluntary movements reveal that six species of pleuronectid flatfishes use sequential portions of long-based dorsal and anal fins as “feet” (hereafter, fin-feet) to move on the substrate. All six species used a gait that we term “walking,” which produced constant forward movement, and several of these species also used a...
Training in science, technology, engineering, and mathematics (STEM) is a top priority for driving economic growth and maintaining technological competitiveness. We propose that exposure to a rigorous research program as an undergraduate leads to success in a research STEM career. We compared the scientific outcomes of 88 participants from five Nat...
Batoids are a diverse clade of flat cartilaginous fishes that occur primarily in benthic marine habitats. The skates and rays typically use their flexible pectoral fins for feeding and propulsion via undulatory swimming. However, two groups of rays have adopted a pelagic or bentho‐pelagic lifestyle and utilize oscillatory swimming—the Myliobatidae...
Batoids (skates and stingrays), exhibit swimming modes that can be characterized on a spectrum from undulation (>1 wave present along the fin) to oscillation (<0.5 wave present along the fin). The latter is a derived mode of locomotion that evolved in a group of charismatic batoids that have invaded pelagic environments (family Myliobatidae: manta...
A new species of clingfish, Dellichthystrnskiisp. n. is described on the basis of 27 specimens, 11.9–46.0 mm SL, collected from intertidal and shallow coastal waters of New Zealand. It is distinguished from its only congener, D.morelandi Briggs, 1955 by characters of the cephalic sensory system and oral jaws, snout shape, and colouration in life. A...
The Sarcastic Fringehead (Neoclinus blanchardi, Teleostei) exhibits an extreme version of a common aggressive display, the “gaping display,” in which an open mouth is presented toward an opponent. Males of this species have extremely long jaws that extend posteriorly well past the posterior margin of the head and are flared laterally during the gap...
Although rare within the context of 30 000 species of extant fishes, scale-feeding as an ecological strategy has evolved repeatedly across the teleost tree of life. Scalefeeding (lepidophagous) fishes are diverse in terms of their ecology, behaviour, and specialized morphologies for grazing on scales and mucus of sympatric species. Despite this div...
The elongate fish body form and anguilliform swimming mode evolved many times across taxa, suggesting a benefit from combining the two. In addition to the well studied 2D bending wave, some elongate fish twist about the long axis, producing a 3D wave of motion. Despite similar body plans and 2D swimming mode, the 3D wave varies across species. Some...
We contrast 2D vs. 3D landmark-based geometric morphometrics in the fish subfamily Oligocottinae by using 3D landmarks from CT-generated models and comparing the morphospace of the 3D landmarks to one based on 2D landmarks from images. The 2D and 3D shape variables capture common patterns across taxa, such that the pairwise Procrustes distances amo...
Hagfishes defend themselves from fish predators by releasing large volumes of gill-clogging slime when they are attacked. Slime release is not anticipatory, but is only released after an attack has been initiated, raising the question of how hagfishes survive the initial attack, especially from biting predators such as sharks. We tested two hypothe...
Many deep-sea fishes have a gelatinous layer, or subdermal extracellular matrix, below the skin or around the spine. We document the distribution of gelatinous tissues across fish families (approx. 200 species in ten orders), then review and investigate their composition and function. Gelatinous tissues from nine species were analysed for water con...
The skin and blubber of marine mammals provides protection from the surrounding environment, whether that be temperature, microbes, or direct mechanical impacts. To understand the ability of harbor seals' (Phoca vitulina) skin and blubber to resist blunt force trauma, we tested the material properties of these tissues. We quantified two mechanical...