Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Test”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
USGS2005

Interpretation of transmissivity estimates from single-well pumping aquifer tests

Interpretation of single-well tests with the Cooper-Jacob method remains more reasonable than most alternatives. Drawdowns from 628 simulated single-well tests where transmissivity was specified were interpreted with the Cooper-Jacob straight-line method to estimate transmissivity. Error and bias as a function of vertical anisotropy, partial penetration, specific yield, and interpretive technique were investigated for transmissivities that ranged from 10 to 10,000 m2/d. Cooper-Jacob transmissivity estimates in confined aquifers were affected minimally by partial penetration, vertical anisotropy, or analyst. Cooper-Jacob transmissivity estimates of simulated unconfined aquifers averaged twice the known values. Transmissivity estimates of unconfined aquifers were not improved by interpreting results with an unconfined aquifer solution. Judicious interpretation of late-time data consistently improved estimates where transmissivity exceeded 250 m2/d in unconfined aquifers. ?? 2006 National Ground Water Association.

Ground Water↗
USGS2007

A field test of electromigration as a method for remediating sulfate from shallow ground water

Eloctromigraiion offers a potential tool for remediating ground water contaminated with highly soluble components, such as Na + , Cl, NO 3 and SO 4 − . A field experiment was designed to lest the efficacy of electromigration for preconcontrating dissolved SO 4 2 in ground water associated with a fossil-fuel power plant. Two shallow wells, 25 feel apart (one 25 feel deep, the other 47 feet deep), were constructed in the upper portion of an unconfined alluvial aquifer. The wells were constructed with a double-wall design, with an outer casing of 4-inch PVC and an inner lube of 2-inch FVC; both were fully slotted (0.01 inch). Electrodes were constructed by wrapping the inner lulling with a 100-foot length of rare-earth metal oxide/copper wire. An electrical potential of 10.65 volts DC Was applied, and tests were run for periods of 12, 44, and 216 hours. Results showed large changes in the pH from the initial pH of ground water of about 7.5 to values of approximately 2 and 12 at the anode and cathode, respectively. Despite the fact that the test conditions were far from ideal, dissolved SO 4 2- ; was significantly concentrated at the anode. Over a period of approximately nine days, the concentration of SO 4 2- at the anode reached what appeared to he a steady-state value of 2200 mg/L. compared lo the initial value in ground water of approximately 1150 mg/L. The results of this field lest should encourage further investigation of electromigration as a tool in the remediation of contaminated ground water.

Ground Water Monitoring and Remediation↗
USGS2007

Numerical model of a tracer test on the Santa Clara River, Ventura County, California

To better understand the flow processes, solute-transport processes, and ground-water/surface-water interactions on the Santa Clara River in Ventura County, California, a 24-hour fluorescent-dye tracer study was performed under steady-state flow conditions on a 45-km reach of the river. The study reach includes perennial (uppermost and lowermost) subreaches and ephemeral subreaches of the lower Piru Creek and the middle Santa Clara River. The tracer-test data were used to calibrate a one-dimensional flow model (DAFLOW) and a solute-transport model (BLTM). The dye-arrival times at each sample location were simulated by calibrating the velocity parameters in DAFLOW. The simulations of dye transport indicated that (1) ground-water recharge explains the loss of mass in the ephemeral middle subreaches, and (2) groundwater recharge does not explain the loss of mass in the perennial uppermost and lowermost subreaches. The observed tracer curves in the perennial subreaches were indicative of sorptive dye losses, transient storage, and (or) photodecay - these phenomena were simulated using a linear decay term. However, analysis of the linear decay terms indicated that photodecay was not a dominant source of dye loss.To better understand the flow processes, solute-transport processes, and ground-water/surface-water interactions on the Santa Clara River in Ventura County, California, a 24-hour fluorescent-dye tracer study was performed under steady-state flow conditions on a 45-km reach of the river. The study reach includes perennial (uppermost and lowermost) subreaches and ephemeral subreaches of the lower Piru Creek and the middle Santa Clara River. The tracer-test data were used to calibrate a one-dimension-al flow model (DAFLOW) and a solute-transport model (BLTM). The dye-arrival times at each sample location were simulated by calibrating the velocity parameters in DAFLOW. The simulations of dye transport indicated that (1) ground-water recharge explains the loss of mass in the ephemeral middle subreaches, and (2) ground-water recharge does not explain the loss of mass in the perennial uppermost and lowermost subreaches. The observed tracer curves in the perennial subreaches were indicative of sorptive dye losses, transient storage, and (or) photodecay - these phenomena were simulated using a linear decay term. However, analysis of the linear decay terms indicated that photodecay was not a dominant source of dye loss.

Journal of the American Water Resources Associatio↗
USGS2017

Experimental test of genetic rescue in isolated populations of brook trout

Genetic rescue is an increasingly considered conservation measure to address genetic erosion associated with habitat loss and fragmentation. The resulting gene flow from facilitating migration may improve fitness and adaptive potential, but is not without risks (e.g., outbreeding depression). Here, we conducted a test of genetic rescue by translocating ten (five of each sex) brook trout ( Salvelinus fontinalis ) from a single source to four nearby and isolated stream populations. To control for the demographic contribution of translocated individuals, ten resident individuals (five of each sex) were removed from each recipient population. Prior to the introduction of translocated individuals, the two smallest above-barrier populations had substantially lower genetic diversity, and all populations had reduced effective number of breeders relative to adjacent below-barrier populations. In the first reproductive bout following translocation, 31 of 40 (78%) translocated individuals reproduced successfully. Translocated individuals contributed to more families than expected under random mating and generally produced larger full-sibling families. We observed relatively high (>20%) introgression in three of the four recipient populations. The translocations increased genetic diversity of recipient populations by 45% in allelic richness and 25% in expected heterozygosity. Additionally, strong evidence of hybrid vigour was observed through significantly larger body sizes of hybrid offspring relative to resident offspring in all recipient populations. Continued monitoring of these populations will test for negative fitness effects beyond the first generation. However, these results provide much-needed experimental data to inform the potential effectiveness of genetic rescue-motivated translocations.

Virginia↗
USGS1982

Environmental implications of test-to-substrate attachment among some modern sublittoral foraminifera

Topographic highs on the outer continental shelf of New Jersey are sites for the concentration of three species of attached calcareous benthic foraminifera. Elphidium subarcticum Cushman, normally considered a vagrant species, cements itself by an organic film to one or more quartz grains. Webbinella concave (Williamson) attaches to quartz grains by secreting a flange-like calcite skirt at one side of its globuline test. Vasiglobulina reticulate n. sp. has evolved the most elaborate system of attachment: numerous closely spaced spines connect the globuline test to a thin calcite lamina, which is in turn cemented to quartz grains. The attachment mode of these species suggests that the added weight of the quartz grains may reduce displacement during the periodic resuspension of the shelf sediments by longshore and tidal current motion. The distribution of living populations of these species corroborates sedimentological inferences that little or no modern deposition takes place on the sampled topographic highs.

New Jersey↗
USGS2025

An empirical test of maximum depositional age through paired LA-ICP-MS and CA-ID-TIMS detrital zircon analysis with implications for the “Nevadan orogeny” in the Sierra Nevada foothills, California, U.S.A.

The interpretation of maximum depositional age (MDA) from U-Pb detrital zircon data acquired via laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) or secondary ion mass spectrometry (SIMS) is now routine; however, to date only a few studies have presented tests of such MDAs by subsequently analyzing a subset of the same detrital zircon grains with the more accurate and precise chemical abrasion–isotope dilution–thermal ionization mass spectrometry (CA-ID-TIMS) method. We first generated LA-ICP-MS dates and MDAs from three turbidite sandstone samples of the Late Jurassic Mariposa Formation (Sierra Nevada foothills, California) containing large proportions of young detrital zircon grains (at the time of sediment deposition). We then removed 4–5 of the apparent youngest grains from the epoxy mount and analyzed them with CA-ID-TIMS. Despite a lack of low Th/U or high U (ppm) characteristics that might indicate U-Pb system disturbance, all LA-ICP-MS dates are younger than corresponding CA-ID-TIMS dates, on the same grain, by up to 11.8 m.y. when considered as point estimates. Only two out of 13 paired analyses overlap within error at 95% confidence. We interpret MDAs from our CA-ID-TIMS dates to be the youngest CA-ID-TIMS dates (YTDs). LA-ICP-MS MDAs based on fewer dates from the young tail of the youngest date distribution perform the worst (i.e., furthest from CA-ID-TIMS MDAs), whereas LA-ICP-MS MDA methods that incorporate more dates from the youngest date distribution perform better; the best performing method in all cases is the maximum likelihood algorithm–minimum. The performance of tested LA-ICP-MS MDA methods is improved by removing statistical outlier dates and by removing visually young “outlier” dates that drift away from the primary distribution of young dates. Our paired LA-ICP-MS/CA-ID-TIMS MDA workflow shows that the accuracy of MDA can be significantly improved by conducting CA-ID-TIMS on as few as four grains from a sample. The combination of our new CA-ID-TIMS MDAs with published CA-ID-TIMS analyses and petrochronology on the nearby Guadalupe igneous complex provides sub-million-year resolution of contemporaneous igneous and sedimentary systems during deformation and clarifies the timing of regional deformation that defines the local “Nevadan orogeny.” Rocks in the upper plate of the Bear Mountains fault zone have a CA-ID-TIMS YTD MDA of 151.71 ± 0.23 Ma, and rocks of the lower plate have a CA-ID-TIMS YTD MDA of 149.92 ± 0.11 Ma. These new MDAs, in conjunction with the observation of fabric-bearing Mariposa Formation xenoliths in the ca. 149.65 ± 0.10 Ma Guadalupe igneous complex, suggest that rocks in the upper plate of the Bear Mountains fault zone represent a slightly older (~2 m.y.) section of Mariposa Formation that was deformed and intruded prior to being juxtaposed against, and further deformed with, a slightly younger lower-plate section of Mariposa Formation in actively deforming, fault-bounded basins. Our observations are not consistent with traditional models that require that sedimentation of the Mariposa Formation ended by ca. 155 Ma. Instead, we interpret our data to be consistent with other evidence for a continuum of deformation in Late Jurassic to Early Cretaceous time and document that the regional “slatey cleavage” observed in the greater Mariposa Formation and used to define the “Nevadan orogeny” in our study area is largely younger than 149.92 ± 0.11 Ma.

California↗
USGS2001

Production of stream habitat gradients by montane watersheds: Hypothesis tests based on spatially explicit path analyses

We studied how the features of mountain watersheds interact to cause gradients in three stream attributes: baseflow stream widths, total alkalinity, and stream slope. A priori hypotheses were developed before being tested in a series of path analyses using data from 90 stream reaches on 24 second- to fourth-order streams across a fifth-order Rocky Mountain watershed. Because most of the conventional least squares regressions initially calculated for the path analyses had spatially correlated residuals (13 of 15 regressions), spatially explicit regressions were often used to derive more accurate parameter estimates and significance tests. Our final working hypotheses accounted for most of the variation in baseflow stream width (73%), total alkalinity (74%), and stream slope (78%) and provide systemic views of watershed function by depicting interactions that occur between geomorphology, land surface features, and stream attributes. Stream gradients originated mainly from the unidirectional changes in geomorphic features that occur over the lengths of streams. Land surface features were of secondary importance and, because they change less predictably relative to the stream, appear to modify the rate at which stream gradients change.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2019

Testing theoretical metapopulation conditions with genotypic data from Boreal Chorus Frogs (Pseudacris maculata)

The metapopulation concept has far-reaching implications in ecology and conservation biology. Hanski’s criteria operationally define metapopulations, yet testing them is hindered by logistical and financial constraints inherent to the collection of long-term demographic data. Hence, ecologists and conservationists often assume metapopulation existence for dispersal-limited species that occupy patchy habitats. To advance understanding of metapopulation theory and improve conservation of metapopulations, we used population and landscape genetic tools to develop a methodological framework for evaluating Hanski’s criteria. We used genotypic data (11 microsatellite loci) from a purported metapopulation of Boreal Chorus Frogs ( Pseudacris maculata (Agassiz, 1850)) in Colorado, U.S.A., to test Hanski’s four criteria. We found support for each criterion: (1) significant genetic differentiation between wetlands, suggesting distinct breeding populations; (2) wetlands had small effective population sizes and recent bottlenecks, suggesting populations do not experience long-term persistence; (3) population graphs provided evidence of gene flow between patches, indicating potential for recolonization; and (4) multiscale bottleneck analyses suggest asynchrony, indicating that simultaneous extinction of all populations was unlikely. Our methodological framework provides a logistically and financially feasible alternative to long-term demographic data for identifying amphibian metapopulations.

Colorado↗
USGS1987

Testing of male sockeye salmon ( Oncorhynchus nerka ) and steelhead trout ( Salmo gairdneri ) for infectious hematopoietic necrosis virus

Infectious hematopoietic necrosis (IHN) virus has been isolated only rarely from whole milt samples of male sockeye salmon ( Oncorhynchus nerka ). In 3 yr of testing, virus incidences in males ranged from 0 to 13% when milt was sampled but were 60–100% with spleen or kidney. When IHN virus was isolated from sockeye salmon milt at titers less than 3.00 log 10 plaque-forming units (pfu)/mL, the level of virus in the kidney or spleen exceeded 7.00 log 10 pfu/g. Higher rates of IHN virus isolation from kidney or spleen than from milt were also generally found in steelhead trout ( Salmo gairdneri ), although the differences were less pronounced than in sockeye salmon. Furthermore, virus was sometimes isolated from steelhead trout milt when the level of virus in kidney or spleen samples was very low, and was recovered from some milt samples when none was isolated from the corresponding spleen sample. When male salmonids are tested for IHN virus, kidney or spleen samples are superior to whole milt, but milt should be included for critical examinations.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2000

Prodigious polyphyly in imperilled freshwater pearly-mussels (Bivalvia: Unionidae): a phylogenetic test of species and generic designations

Unionid bivalves or freshwater pearly-mussels (Unionoidea: Unionidae) serve as an exemplary system for examining many of the problems facing systematists and conservation biologists today. Most of the species and genera were described in the late 1800s and early 1900s, but few phylogenetic studies have been conducted to test conventional views of species and classification. Pearly-mussels of Gulf Coastal drainages of the southeastern United States from the Escambia (southern Alabama to Florida) to the Suwannee Rivers (Florida) are a unique fauna comprised of approximately 100 species, with about 30 endemic to the region. In this study, mitochondrial cytochrome c oxidase subunit I and 16S rRNA gene sequences were used to test the monophyly and to estimate evolutionary relationships of five unionid species representing three different genera. The molecular phylogenies depict all three genera as polyphyletic. The prodigious polyphyly exhibited within unionids is due to incorrect notions of homology and false assumptions about missing anatomical data. In contrast, the molecular phylogeny provides evidence to support the recognition of all five unionid species as distinct evolutionary entities. Furthermore, molecular genealogical evidence supports the elevation of Quincuncina infucata (Conrad) of the Suwannee River to species level, for which Q. kleiniana (Lea) is available.

Geological Society Special Publication↗
USGS2022

Paradigm versus paradox on the prairie: Testing competing stream fish movement frameworks using an imperiled Great Plains minnow

Background Movement information can improve conservation of imperiled species, yet movement is not quantified for many organisms in need of conservation. Prairie chub ( Macrhybopsis australis ) is a regionally endemic freshwater fish with unquantified movement ecology and currently considered for listing under the Endangered Species Act. The purpose of this study was to test competing ecological theories for prairie chub movement, including the colonization cycle hypothesis (CCH) that posits adults must make upstream movements to compensate for downstream drift at early life stages, and the restricted movement paradigm (RMP) that describes populations as heterogeneous mixes of mostly stationary and few mobile fish. Methods We tagged prairie chub with visible implant elastomer during the summer (May–August) of 2019 and 2020 to estimate net distance moved (m) and movement rate (m/d). We tested the hypotheses that observed prairie chub movement would be greater than expected under the RMP and that prairie chub movement would be biased in an upstream direction as predicted by the CCH. Results We tagged 5771 prairie chub and recaptured 213 individuals across 2019 and 2020. The stationary and mobile components of the prairie chub population moved an order of magnitude further and faster than expected under the RMP during both years. However, we found only limited evidence of upstream bias in adult prairie chub movement as would be expected under the CCH. Conclusions Our findings are partly inconsistent with the RMP and the CCH, and instead closely follow the drift paradox (DP), in which upstream populations persist despite presumed downstream drift during early life stages and in the apparent absence of upstream bias in recolonization. Previous mathematical solutions to the DP suggest organisms that experience drift maintain upstream populations through either minimization of drift periods such that small amounts of upstream movement are needed to counter the effects of advection or increasing dispersal regardless of directionality. We conclude that the resolution to the DP for prairie chub is an increase in total dispersal and our results provide insight into the spatial scales at which prairie chub conservation and management may need to operate to maintain broad-scale habitat connectivity.

Oklahoma, Texas↗
USGS1985

Statistical evaluation of an inductively coupled plasma atomic emission spectrometric method for routine water quality testing

In an interlaboratory test, inductively coupled plasma atomic emission spectrometry (ICP-AES) was compared with flame atomic absorption spectrometry and molecular absorption spectrophotometry for the determination of 17 major and trace elements in 100 filtered natural water samples. No unacceptable biases were detected. The analysis precision of ICP-AES was found to be equal to or better than alternative methods. Known-addition recovery experiments demonstrated that the ICP-AES determinations are accurate to between plus or minus 2 and plus or minus 10 percent; four-fifths of the tests yielded average recoveries of 95-105 percent, with an average relative standard deviation of about 5 percent.

Applied Spectroscopy↗
USGS2016

Potential of environmental DNA to evaluate Northern pike ( Esox lucius ) eradication efforts: An experimental test and case study

Determining the success of invasive species eradication efforts is challenging because populations at very low abundance are difficult to detect. Environmental DNA (eDNA) sampling has recently emerged as a powerful tool for detecting rare aquatic animals; however, detectable fragments of DNA can persist over time despite absence of the targeted taxa and can therefore complicate eDNA sampling after an eradication event. This complication is a large concern for fish eradication efforts in lakes since killed fish can sink to the bottom and slowly decay. DNA released from these carcasses may remain detectable for long periods. Here, we evaluated the efficacy of eDNA sampling to detect invasive Northern pike ( Esox lucius ) following piscicide eradication efforts in southcentral Alaskan lakes. We used field observations and experiments to test the sensitivity of our Northern pike eDNA assay and to evaluate the persistence of detectable DNA emitted from Northern pike carcasses. We then used eDNA sampling and traditional sampling (i.e., gillnets) to test for presence of Northern pike in four lakes subjected to a piscicide-treatment designed to eradicate this species. We found that our assay could detect an abundant, free-roaming population of Northern pike and could also detect low-densities of Northern pike held in cages. For these caged Northern pike, probability of detection decreased with distance from the cage. We then stocked three lakes with Northern pike carcasses and collected eDNA samples 7, 35 and 70 days post-stocking. We detected DNA at 7 and 35 days, but not at 70 days. Finally, we collected eDNA samples ~ 230 days after four lakes were subjected to piscicide-treatments and detected Northern pike DNA in 3 of 179 samples, with a single detection at each of three lakes, though we did not catch any Northern pike in gillnets. Taken together, we found that eDNA can help to inform eradication efforts if used in conjunction with multiple lines of inquiry and sampling is delayed long enough to allow full degradation of DNA in the water.

PLoS ONE↗
USGS2022

Testing the potential of streamflow data to predict spring migration of an ungulate herds

In mountainous and high latitude regions, migratory animals exploit green waves of emerging vegetation coinciding with rising daily mean temperatures initiating snowmelt across the landscape. Snowmelt also causes rivers and streams draining these regions to swell, a process referred to as to as the ‘spring pulse.’ Networks of streamgages measuring streamflow in these regions often have long-term and continuous periods of record available in real-time and at the daily time step, and thus produce data with potential to predict temporal migration patterns for species exploiting green waves. We tested the potential of models informed by streamflow data to predict timing of spring migration of mule deer ( Odocoileus hemionus ) herds in a headwater basin of the Colorado River. Models using streamflow data were compared with those informed by traditional temperature-derived measures of the onset of spring. Non-parametric linear-regression techniques were used to test for temporal stationarity in each variable, and logistic-regression models were used to produce probabilities of migration initiation. Our analysis indicates that models using daily streamflow data can perform as well as those using temperature-derived data to predict past-migration patterns, and nearly as well in potential to forecast future migrations. The best performing model was used to generate probabilities of onset of migration for mule deer herds over the 69-year period-of-record from a streamgage. That model indicated spring migration has been trending toward earlier initiations, with modeled median initiations shifting from a Julian day of 123 in the mid 20 th century to Julian day 115 over the most recent two decades. The period of 1960 to 1979 had the latest modeled median initiations with Julian day of 128. The analyses demonstrate promise for merging existing hydrologic and biological data collection platforms in these regions to explore timing of past migration patterns and predict migration onsets in real-time.

Colorado, Wyoming↗
USGS2022

Diagnostic testing of chronic wasting disease in white-tailed deer (Odocoileus virginianus) by RT-QuIC using multiple tissues

Chronic wasting disease (CWD) is a fatal prion disease affecting cervids (deer, elk, moose). Current methods to monitor individual disease state include highly invasive antemortem rectal biopsy or postmortem brain biopsy. Efficient, sensitive, and selective antemortem and postmortem testing of populations would increase knowledge of the dynamics of CWD epizootics as well as provide a means to track CWD progression into previously unaffected areas. Here, we analyzed the presence of CWD prions in skin samples from two easily accessed locations (ear and belly) from 30 deceased white-tailed deer ( Odocoileus viginianus ). The skin samples were enzymatically digested and analyzed by real-time quaking-induced conversion (RT-QuIC). The diagnostic sensitivity of the ear and belly skin samples were both 95%, and the diagnostic specificity of the ear and belly skin were both 100%. Additionally, the location of the skin biopsy on the ear does not affect specificity or sensitivity. These results demonstrate the efficacy of CWD diagnosis with skin biopsies using RT-QuIC. This method could be useful for large scale antemortem population testing.

Wisconsin↗
USGS1982

Subacute toxicity testing with young birds: Response in relation to age and intertest variability of LC50 estimates

The variability in toxic response of Japanese quail (Coturnix coturnix japonica) to a standardized 5-day subacute feeding trial was studied while age was increased at weekly intervals from 1 to 21 days and at different times with 14-day-old birds. The objectives were to identify the strengths and limitations of this subacute toxicity protocol and to provide possible explanations for differences in response among the various classes of pesticides. The variables included the median lethal concentration (LC50), the dose-response slope, food consumption, mortality patterns, and procedures of preparing toxic diets. Carbamate, organophosphate, chlorinated hydrocarbon, and organic mercury compounds were represented. A total of 60 subacute tests were involved in this evaluation. The general conclusions of the study are as follows: (1) The basic protocol yields good within-laboratory reproducibility of results. (2) The LC50s increase as birds grow older, and the change was reasonably predictable between 7 and 21 days of age. (3) Monitoring of time-related response patterns, such as food consumption, onset and remission of overt toxicity, and mortality, is critical to the evaluation of potential hazard. (4) Different orders of toxicity may occur at different ages for an array of compounds, but differences do not appear to be large enough to seriously alter the interpretation. (5) For optimal comparisons, all testing should be conducted on birds of a single age.

Book chapter↗
USGS1999

Testing and extension of a sea lamprey feeding model

A previous model of feeding by sea lamprey Petromyzon marinus predicted energy intake and growth by lampreys as a function of lamprey size, host size, and duration of feeding attachments, but it was applicable only to lampreys feeding at 10°C and it was tested against only a single small data set of limited scope. We extended the model to other temperatures and tested it against an extensive data set (more than 700 feeding bouts) accumulated during experiments with captive sea lampreys. Model predictions of instantaneous growth were highly correlated with observed growth, and a partitioning of mean squared error between model predictions and observed results showed that 88.5% of the variance was due to random variation rather than to systematic errors. However, deviations between observed and predicted values varied substantially, especially for short feeding bouts. Predicted and observed growth trajectories of individual lampreys during multiple feeding bouts during the summer tended to correspond closely, but predicted growth was generally much higher than observed growth late in the year. This suggests the possibility that large overwintering lampreys reduce their feeding rates while attached to hosts. Seasonal or size-related shifts in the fate of consumed energy may provide an alternative explanation. The lamprey feeding model offers great flexibility in assessing growth of captive lampreys within various experimental protocols (e.g., different host species or thermal regimes) because it controls for individual differences in feeding history.

Transactions of the American Fisheries Society↗