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USGS1998

Morphologic and cytochemical characteristics of blood cells from Hawaiian green turtles

Objective - To identify and characterize blood cells from free-ranging Hawaiian green turtles, Chelonia mydas. Sample Population - 26 green turtles from Puako on the island of Hawaii and Kaneohe Bay on the island of Oahu. Procedure - Blood was examined, using light and electron microscopy and cytochemical stains that included benzidine peroxidase, chloroacetate esterase, alpha naphthyl butyrate esterase, acid phosphatase, Sudan black B, periodic acid-Schiff, and toluidine blue. Results - 6 types of WBC were identified: lymphocytes, monocytes, thrombocytes, heterophils, basophils, and eosinophils (small and large). Morphologic characteristics of mononuclear cells and most granulocytes were similar to those of cells from other reptiles except that green turtles have both large and small eosinophils. Conclusions - Our classification of green turtle blood cells clarifies imporoper nomenclature reported previously and provides a reference for future hematologic studies in this species.

Hawai'i↗

USGS2024

Atlas of microscopic images of biochar using reflected light microscopy in biochar characterization

Derived through the thermochemical conversion of biomass, biochar is a carbon-rich substance recognized for its significance in environmental applications and sustainable agriculture. As interest in its utilization continues to rise, it becomes crucial to comprehend how the source material and pyrolysis parameters influence the properties of biochar and, consequently, to research the suitability of various analytical methods for characterizing it. Despite the current utilization of numerous physical and chemical methods, the untapped potential of reflected light microscopy warrants further exploration. While a few recent studies suggest a correlation between certain microscopic characteristics and selected physical and chemical properties of biochar, the data are limited and difficult to compare. This is primarily due to variations in the types of original biomass used and lack of information about pyrolysis conditions. Moreover, because only a limited number of photographs taken under a reflected light microscope are publicly available to-date, it is difficult to evaluate morphological differences between various biochars and other organic materials such as inertinites from coal, charcoal, etc. To address limited availability of publicly available data, this “Atlas of Microscopic Images of Biochar” presents a collection of more than 300 images contributed by researchers from Poland, the United States, Canada, Australia, Brazil, and Denmark. These photomicrographs capture optical characteristics of a diverse array of biochar, demonstrating its unique morphological and structural features. This visual documentation can serve as a valuable resource for researchers, industry professionals, educators, and enthusiasts interested in investigating the complexities of biochar forms.

Indiana Journal of Earth Sciences↗

USGS2023

Hidden in the hills: Phylogeny of the freshwater mussel genus Alasmidonta (Bivalvia: Unionidae) and description of a new species

Inaccurate taxonomy can lead to species in need of conservation being overlooked, which makes revisionary systematics crucially important for imperilled groups. The freshwater mussel genus Alasmidonta is one such group in need of study. Here, we take a multilocus phylogenetic approach to assess species-level taxonomy of Alasmidonta and test monophyly of this genus. Phylogenetic inference resulted in polyphyly of Alasmidonta . Lasmigona , which was included to test monophyly of Alasmidonta , was also polyphyletic. Species delimitation methods disagreed about whether Alasmidonta arcula , Alasmidonta triangulata and Alasmidonta undulata are distinct species, but all delimitation methods agreed that Alasmidonta harbours an undescribed species that would be considered Alasmidonta varicosa under current taxonomy. Given conflict among species delimitation methods and geographical separation, we maintain the current taxonomy for A. arcula and A. triangulata . The undescribed species is restricted to rivers of the Uwharrie Mountains region in North Carolina, USA that flow into the Pee Dee River from the east and can be distinguished morphologically from A. varciosa by higher and wider placed adductor mussels and a hooked pseudocardinal tooth. We offer insights into how supraspecific taxonomy of subtribe Alasmidontina might be resolved and formally describe the lineage from the Uwharrie Mountains region as Uwharrie elktoe, Alasmidonta uwharriensis sp. nov.

North Carolina↗

USGS1994

Characteristics of zircons from volcanic ash-derived tonsteins in Late Permian coal fields of eastern Yunnan, China

Kaolinitic tonsteins of altered synsedimentary volcanic ash-fall origin are well developed in the Late Permian coal-bearing formations of eastern Yunnan Province. Because of their unique origin, wide lateral extent, relatively constant thickness and sharp contacts with enclosing strata, great importance has been attached to these isochronous petrographic markers. In order to compare tonsteins with co-existing, non-cineritic claystones and characterize the individuality of tonsteins from different horizons for coal bed correlation, a semi-quantitative method was developed that is based on statistical analyses of the concentration and morphology of zircons and their spatial distribution patterns. This zircon-based analytical method also serves as a means for reconstructing volcanic ash-fall dispersal patterns. The results demonstrate that zircons from claystones of two different origins (i.e., tonstein and non-cineritic claystone) differ greatly in their relative abundances, crystal morphologies and spatial distribution patterns. Tonsteins from the same area but from different horizons are characterized by their own unique statistical patterns in terms of zircon concentration values and morphologic parameters (crystal length, width and the ratio of these values), thus facilitating stratigraphic correlation. Zircons from the same tonstein horizon also show continuous variation in these statistical patterns as a function of areal distribution, making it possible to identify the main path and direction in which the volcanic source materials were transported by prevailing winds.

International Journal of Coal Geology↗

USGS2000

Identification of a small, naked virus in tumor-like aggregates in cell lines derived from a green turtle, Chelonia mydas, with fibropapillomas

Serial cultivation of cell lines derived from lung, testis, periorbital and tumor tissues of a green turtle (Chelonia mydas) with fibropapillomas resulted in the in vitro formation of tumor-like cell aggregates, ranging in size from 0.5 to 2.0 mm in diameter. Successful induction of tumor-like aggregates was achieved in a cell line derived from lung tissue of healthy green turtles, following inoculation with cell-free media from these tumor-bearing cell lines, suggesting the presence of a transmissible agent. Thin-section electron microscopy of the cell aggregates revealed massive collagen deposits and intranuclear naked viral particles, measuring 5095 nm in diameter. These findings, together with the morphological similarity between these tumor-like cell aggregates and the naturally occurring tumor, suggest a possible association between this novel virus and the disease. Further characterization of this small naked virus will clarify its role in etiology of green turtle fibropapilloma, a life-threatening disease of this endangered marine species.

Journal of Virological Methods↗

USGS2009

At the foot of the shrew: Manus morphology distinguishes closely-related Cryptotis goodwini and Cryptotis griseoventris (Mammalia: Soricidae) in Central America

Small-eared shrews (Mammalia, Soricidae) of the New World genus Cryptotis are distributed from eastern North America to the northern Andes of South America. One well-defined clade in this genus is the Central American Cryptotis mexicana group, whose members are set off from other species in the genus by their variably broader fore feet and more elongate and broadened fore claws. Two species in the C. mexicana group, Cryptotis goodwini Jackson and Cryptotis griseoventris Jackson, inhabit highlands in Guatemala and southern Mexico and are presumed to be sister species whose primary distinguishing feature is the larger body size of C. goodwini. To better characterize these species and confirm the identification of recently-collected specimens, we obtained digital X-ray images of the manus from large series of dried skins of both species. Measurements of the metacarpals and phalanges successfully separated most specimens of C. goodwini and C. griseoventris . These measurements also show that the fore feet of C. griseoventris from Chiapas, Mexico, are morphologically distinct from those of members of the species inhabiting Guatemala. Univariate, bivariate, and multivariate analyses indicate that fore foot characters are more conservative within species of the C. mexicana group than are cranio-mandibular characters. Patterns of evolution of fore foot characters that superficially appear to be linear gradations are actually more complex, illustrating individual evolutionary trajectories.

Biological Journal of the Linnean Society↗

USGS2010

Two new species of shrews (Soricidae) from the western highlands of Guatemala

The broad-clawed shrews (Soricomorpha: Soricidae: Cryptotis ) encompass a clade of 5 species— Cryptotis alticolus (Merriam), C. goldmani (Merriam), C. goodwini Jackson, C. griseoventris Jackson, and C. peregrinus (Merriam)—that is known collectively as the Cryptotis goldmani group and is characterized by broadened forefeet, elongated and broadened fore claws, and broadened humeri. These shrews are distributed in highland regions from central Mexico to Honduras. Two broad-clawed shrews, C. goodwini and C. griseoventris , occur in southern Mexico and Guatemala and are presumed sister species whose primary distinguishing feature is the larger size of C. goodwini . In an investigation of variation within and between these 2 species, I studied characteristics of the postcranial skeleton. Statistical analyses of a variety of character suites indicate that the forelimb morphology in this group exhibits less intraspecific variation and greater interspecific variation than cranio-mandibular morphology, although most skull characters support groupings based on forelimb characters. Together, these characters define 4 distinct groups among the specimens examined. C. griseoventris is restricted to the northern highlands of Chiapas, Mexico, and C. goodwini occurs in the southern highlands of Chiapas and Guatemala. Herein, I describe 2 new species of broad-clawed shrews from the Sierra de los Cuchumatanes, Guatemala.

Journal of Mammalogy↗

USGS2013

Measurement of bovine sperm nuclear shape using Fourier harmonic amplitudes

An objective method for measuring bovine sperm nuclear shape was developed. Digital images of bovine sperm stained with propidium iodide were collected and Fourier functions used to describe the perimeters of individual sperm nuclei. Harmonic amplitudes from Fourier functions were first shown to be independent of sperm orientation during digitization. Sperm from 12 different bulls were used, and 6 harmonic amplitudes per sperm were found to adequately describe sperm nuclear shape. Based on harmonic amplitudes 0 to 5, cluster analysis was used to generate 20 different groups. Sperm within groups had similar morphologies and groups were distinguished by statistically unique shape characteristics. Harmonic amplitudes 0 to 5 can be used to distinguish previously reported abnormalities such as tapered, pyriform, macrocephalic, and microcephalic, as well as gradations in between. Furthermore, differences were detected among bull harmonic amplitude centroids ( P < .05), indicating that bulls differ in mean sperm nuclear shape.

Journal of Andrology↗

USGS2022

Non-target effects of herbicides on the Zerene silverspot butterfly, a surrogate subspecies for the threatened Oregon silverspot butterfly

Herbicides are used as management tools to improve habitat for native plants and animals, but their application may also have harmful effects on the native community. The federally threatened Oregon silverspot butterfly ( Speyeria = Argynnis zerene hippolyta ) resides in remnant native grasslands along the Pacific Northwest coast. However, like many grasslands, many of these areas have high incidences of invasive plants, such as false dandelion ( Hypochaeris radicata ) and velvet grass ( Holcus lanatus ). These and other invasive plants severely limit the abundance of the Oregon silverspot’s larval host plant, the early blue violet ( Viola adunca ). Selective herbicides, such as clopyralid and fluazifop-P-butyl, can reduce invasive plant abundance. However, non-target effects of these herbicides, and of adjuvants applied with these herbicides, on Oregon silverspots are unknown. In our study, we applied herbicides and adjuvants to host plants and Zerene silverspot ( S. z. zerene ) larvae, a subspecies closely related to Oregon silverspots. Responses in silverspot larvae measured in two experiments included survival, sex ratio, development time, mass, morphology, fecundity, and behavior. Our results suggest that negative effects of herbicides, clopyralid and fluazifop-P-butyl, and adjuvants, Agri-Dex ® and Nu-Film ® -IR, are limited. However, we detected weak effects from clopyralid and fluazifop-P-butyl with and without Agri-Dex ® on larval and pupal development time and pupal mass.

Journal of Insect Conservation↗

USGS2016

Response and resilience of Spartina alterniflora to sudden dieback

We measured an array of biophysical and spectral variables to evaluate the response and recovery of Spartina alterniflora to a sudden dieback event in spring and summer 2004 within a low marsh in coastal Virginia, USA. S. alterniflora is a foundation species, whose loss decreases ecosystem services and potentiates ecosystem state change. Long-term records of the potential environmental drivers of dieback such as precipitation and tidal inundation did not evidence any particular anomalies, although Hurricane Isabel in fall 2003 may have been related to dieback. Transects were established across the interface between the dieback area and apparently healthy areas of marsh. Plant condition was classified based on ground cover within transects as dieback, intermediate and healthy. Numerous characteristics of S. alterniflora culms within each condition class were assessed including biomass, morphology and spectral attributes associated with photosynthetic pigments. Plants demonstrated evidence of stress in 2004 and 2005 beyond areas of obvious dieback and resilience at a multi-year scale. Resilience of the plants was evident in recovery of ground cover and biomass largely within 3 y, although a small remnant of dieback persisted for 8 y. Culms surviving within the dieback and areas of intermediate impact had modified morphological traits and spectral response that reflected stress. These morphometric and spectral differences among plant cover condition classes serve as guidelines for monitoring of dieback initiation, effects and subsequent recovery. Although a number of environmental and biotic parameters were assessed relative to causation, the reason for this particular dieback remains largely unknown, however.

Virginia↗

USGS1978

Trenches across the 1906 trace of the San Andreas Fault in northern San Mateo County, California

Two trenches were excavated across the 1906 trace of the San Andreas fault near fences that were displaced by the 1906 faulting. About 18 displacements equal to the 1906 displacement would account for the offset of a stream adjacent to one of the trenches. Review of divergent reports on the amount of fault displacement in 1906 at 7 localities indicates that right slip ranged from about 2 in (meters) to about 3 m at the main trace and was about 0.6 m on a subsidiary trace near one of the trench sites. Materials exposed in the trenches included Franciscan bedrock, Merced (?) sandstone, alluvial deposits, and modern soils. Visibility of the evidence for faulting covered a wide range. Faulting was expressed in the trenches as conspicuous color differences, abrupt termination of geologic units, fractures, gouge, granulation of rock, streaked contacts, rounding of rock fragments, and slickensides. Irregularly shaped masses of gouge and other materials found in both trenches may also be a manifestation of faulting. Neither caving of the walls nor the inflow of ground water were reliable indicators of the locations of faults in these trenches. The features exposed in the trenches clearly indicated the presence of an important zone of faults with geologically young displacements, but they were inadequate to identify with certainty the 1906 break or the probable 1838 break. For example, evidence of the 1906 rupture could not be seen in a unit 200 mm (millimeters) thick that is believed to predate 1906. The approximate location in the trenches of the 1906 zone of ruptures could, however, be inferred from surface morphology, historic records, and evidence in the trenches. A moderately sharp and steep contact between two surface soils, in itself suggestive of very young faulting, did not have a fault below it. Brass monuments were installed at the trench sites so that future surface ruptures can be related to the faults and other structures mapped in the trenches.

California↗

USGS2008

Application of morphologic burrow interpretations to discern continental burrow architects: Lungfish or crayfish?

A methodology for trace fossil identification using burrowing signatures is tested by evaluating ancient and modern lungfish and crayfish burrows and comparing them to previously undescribed burrows in a stratigraphic interval thought to contain both lungfish and crayfish burrows. Permian burrows that bear skeletal remains of the lungfish Gnathorhiza , from museum collections, were evaluated to identify unique burrow morphologies that could be used to distinguish lungfish from crayfish burrows when fossil remains are absent. The lungfish burrows were evaluated for details of the burrowing mechanism preserved in the burrow morphologies together forming burrowing signatures and were compared to new burrows in the Chinle Formation of western Colorado to test the methodology of using burrow signatures to identify unknown burrows. Permian lungfish aestivation burrows show simple, nearly vertical, unbranched architectures and relatively smooth surficial morphologies with characteristic quasi‐horizontal striae on the burrow walls and vertical striae on the bulbous terminus. Burrow lengths do not exceed 0.5 m. In contrast, modern and ancient crayfish burrows exhibit simple to highly complex architectures with highly textured surficial morphologies. Burrow lengths may reach 4 to 5 m. Burrow morphologies unlike those identified in Gnathorhiza aestivation burrows were found in four burrow groups from museum collections. Two of these groups exhibit simple architectures and horizontal striae that were greater in sinuosity and magnitude, respectively. One of these burrows contains the remains of Lysoro‐phus , but the burrow surface reveals no reliable surficial characteristics. It is not clear whether Lysorophus truly burrowed or merely occupied a pre‐existing structure. The other two groups exhibit surficial morphologies similar to those found on modern and ancient crayfish burrows and may provide evidence of freshwater crayfish in the Permian. Burrows from the Upper Triassic Chinle Formation in western Colorado exhibit simple to moderately complex architectural morphologies, ranging from predominantly vertical, unbranched, with little or no chamber development to predominantly vertical, few branches, and with minor chamber development. Surficial burrow morphologies are moderate to highly textured. The burrows have scrape marks, scratch marks, mud and lag‐liners, knobby surfaces, pleopod striae, and body impressions. Although no fossil remains of the burrowing organism were found within or associated with the Chinle burrows from western Colorado, the similarity of architectural and surficial burrow morphologies to those in the Chinle of Canyonlands, Utah and to modern crayfish burrows, clearly indicates that the Colorado burrows are the product of burrowing crayfish rather than lungfish. Evaluation of burrowing signatures preserved in the architectural and surficial burrow morphologies is a very useful tool to compare and contrast Chinle burrows from different regions on the Colorado Plateau. Documentation of crayfish burrows in the Chinle of Utah and Colorado strongly suggests that other large‐diameter Chinle burrows elsewhere on the Colorado Plateau and in stratigraphically equivalent units may also be the product of crayfish activity.

Colorado, Utah↗

USGS2017

Isotopic niches support the resource breadth hypothesis

Because a broad spectrum of resource use allows species to persist in a wide range of habitat types, and thus permits them to occupy large geographical areas, and because broadly distributed species have access to more diverse resource bases, the resource breadth hypothesis posits that the diversity of resources used by organisms should be positively related with the extent of their geographic ranges. We investigated isotopic niche width in a small radiation of South American birds in the genus Cinclodes . We analysed feathers of 12 species of Cinclodes to test the isotopic version of the resource breadth hypothesis and to examine the correlation between isotopic niche breadth and morphology. We found a positive correlation between the widths of hydrogen and oxygen isotopic niches (which estimate breadth of elevational range) and widths of the carbon and nitrogen isotopic niches (which estimates the diversity of resources consumed, and hence of habitats used). We also found a positive correlation between broad isotopic niches and wing morphology. Our study not only supports the resource breadth hypothesis but it also highlights the usefulness of stable isotope analyses as tools in the exploration of ecological niches. It is an example of a macroecological application of stable isotopes. It also illustrates the importance of scientific collections in ecological studies.

Journal of Animal Ecology↗

USGS1970

Morphology of certain viruses of Salmonid Fishes. I. in vitro studies of some viruses causing Hematopoietic Necrosis

An electron microscope study was performed on three virus isolates that caused hematopoietic necrosis in salmonid fishes: infectious hematopoietic necrosis (IHN), Oregon Sockeye Disease (OSD), and Sacramento River Chinook Salmon Disease (SRCD). All three isolates were examined by negative staining of fathead minnow (FHM) monolayer tissue culture concentrates and IHN virus was also examined in thin sections of FHM cells. Viruslike particles were observed in infected tissues, but similar structures were not found in uninfected cultures. All three isolates were bullet-shaped, but oval and truncated forms were also observed. Mean measurements of particles from IHN-virus-infected tissue were 158&ensp;×&ensp;90&ensp;mμ. They consisted of an outer coat 15&ensp;mμ thick, a core 60&ensp;mμ in diameter, subunits about 5&ensp;mμ, and an axial pore about 20&ensp;mμ in diameter. These particles also were seen budding from the cytoplasmic membrane. Similar particles from SRCD were 159&ensp;×&ensp;90&ensp;mμ and isolates from OSD were 181&ensp;×&ensp;91&ensp;mμ. The three isolates were morphologically indistinguishable from one another and the greater length of OSD was considered insignificant. IHN, SRCD, and OSD viruses were tentatively placed in the rhabdovirus group, but serological studies are needed to determine if they are antigenically identical or should be included as separate members. Biochemical and physical characteristics of these viruses and a comparison with other salmonid viruses is also discussed.

Journal of the Fisheries Research Board of Canada↗

USGS2002

Observations of the larval stages of Diceroprocta apache Davis (Homoptera: Tibicinidae)

Diceroprocta apache Davis is a locally abundant cicada in the riparian woodlands of the southwestern United States. While its ecological importance has often been hypothesized, very little is known of its specific life history. This paper presents preliminary information on life history of D. apache from larvae collected in the field at seasonal intervals as well as a smaller number of reared specimens. Morphological development of the fore-femoral comb closely parallels growth through distinct size classes. The data indicate the presence of five larval instars in D. apache . Development times from greenhouse-reared specimens suggest a 3-4 year life span and overlapping broods were present in the field. Sex ratios among pre-emergent larvae suggest the asynchronous emergence of sexes.

Journal of the Kansas Entomological Society↗

USGS2012

Divergence in morphology, but not habitat use, despite low genetic differentiation among insular populations of the lizard Anolis lemurinus in Honduras

Studies of recently isolated populations are useful because observed differences can often be attributed to current environmental variation. Two populations of the lizard Anolis lemurinus have been isolated on the islands of Cayo Menor and Cayo Mayor in the Cayos Cochinos Archipelago of Honduras for less than 15 000 y. We measured 12 morphometric and 10 habitat-use variables on 220 lizards across these islands in 2 y, 2008 and 2009. The goals of our study were (1) to explore patterns of sexual dimorphism, and (2) to test the hypothesis that differences in environment among islands may have driven divergence in morphology and habitat use despite genetic homogeneity among populations. Although we found no differences among sexes in habitat use, males had narrower pelvic girdles and longer toe pads on both islands. Between islands, males differed in morphology, but neither males nor females differed in habitat use. Our data suggest that either recent selection has operated differentially on males despite low genetic differentiation, or that they display phenotypic plasticity in response to environmental variation. We suggest that patterns may be driven by variation in intrapopulation density or differences in predator diversity among islands.

Journal of Tropical Ecology↗

USGS2024

Declining geomorphic diversity and potential adaptive management opportunities on a highly regulated reach of the Bighorn River, Montana

Rivers downstream from dams often experience decreased flow variability and disrupted sediment transport. We investigated a highly regulated 35.5-kilometre reach of the Bighorn River, downstream from Yellowtail Dam, emplaced in 1965. This dam created a thriving trout fishery, but more recently, side channel networks and habitat diminished. We document how the Bighorn River's anabranching morphology responded to flow regulation and a near cessation of sediment supply. Geomorphic diversity drastically decreased since 1939 and the Bighorn River abandoned numerous side channels. By 1980, geomorphic loss slowed, and the river became laterally static. The 1980 river and side channel network could represent the maximum areal extent of a downscaled morphology, maintained through restoration and adaptive management. However, side channel restoration alone will not return natural alluvial processes to this river reach. The Bighorn River needs sediment to reinstate dynamic lateral movement, even within a downscaled morphology. Sediment augmentation is an option, but more complex to implement on rivers where potential downstream impacts and landowners must be considered. The decline of geomorphic diversity and potential adaptive management solutions on the Bighorn River has wide applicability to numerous dammed rivers, where similar changes to the flow and sediment transport regime are common.

Montana, Wyoming↗

USGS2011

A distribution-based parameterization for improved tomographic imaging of solute plumes

Difference geophysical tomography (e.g. radar, resistivity and seismic) is used increasingly for imaging fluid flow and mass transport associated with natural and engineered hydrologic phenomena, including tracer experiments, in situ remediation and aquifer storage and recovery. Tomographic data are collected over time, inverted and differenced against a background image to produce ‘snapshots’ revealing changes to the system; these snapshots readily provide qualitative information on the location and morphology of plumes of injected tracer, remedial amendment or stored water. In principle, geometric moments (i.e. total mass, centres of mass, spread, etc.) calculated from difference tomograms can provide further quantitative insight into the rates of advection, dispersion and mass transfer; however, recent work has shown that moments calculated from tomograms are commonly biased, as they are strongly affected by the subjective choice of regularization criteria. Conventional approaches to regularization (Tikhonov) and parametrization (image pixels) result in tomograms which are subject to artefacts such as smearing or pixel estimates taking on the sign opposite to that expected for the plume under study. Here, we demonstrate a novel parametrization for imaging plumes associated with hydrologic phenomena. Capitalizing on the mathematical analogy between moment-based descriptors of plumes and the moment-based parameters of probability distributions, we design an inverse problem that (1) is overdetermined and computationally efficient because the image is described by only a few parameters, (2) produces tomograms consistent with expected plume behaviour (e.g. changes of one sign relative to the background image), (3) yields parameter estimates that are readily interpreted for plume morphology and offer direct insight into hydrologic processes and (4) requires comparatively few data to achieve reasonable model estimates. We demonstrate the approach in a series of numerical examples based on straight-ray difference-attenuation radar monitoring of the transport of an ionic tracer, and show that the methodology outlined here is particularly effective when limited data are available.

Geophysical Journal International↗