scholarly journals Nighttime migrations and behavioral patterns of Pempheris schwenkii

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12412
Author(s):  
Keita Koeda ◽  
Hideyuki Touma ◽  
Katsunori Tachihara
Keyword(s):  
Observation Time ◽  
Migration Pattern ◽  
Small Scale ◽  
Migration Behavior ◽  
Topographic Map ◽  
Long Distance ◽  
Outer Reef ◽  
Reproductive Behaviors ◽  
Water Columns ◽  
Aquarium Tank

Background Although the biomass of the nocturnal fishes is almost same as that of diurnal fishes, most of the ecological studies that examine feeding or reproductive behaviors are on diurnal fishes. Therefore, there is limited ecological information regarding the nocturnal fishes. This fact may be attributed to the difficulty in observing them during darkness. Members of the genus Pempheris (Pempheridae) are one of the most abundant nocturnal fishes on coral reefs. Methods The nighttime migrations of Pempheris schwenkii were observed by attaching a chemical luminescent tag. Tagged fishes were followed by an observer without torch and SCUBA, and their positions and estimated depths were plotted on an underwater topographic map. Aquarium tank observation was carried out to further describe their habits during the night. Results The new tagging method provided good data for observing the migration behavior. In all five observations, the target fishes started nighttime migration from the entrance of their cave within 1 h after sunset. All of them immediately left the inner reef and spent most of the observation time near the surface (0–5 m depth) or shallow (5–15 m depth) water-columns of the outer reef. Their migration pattern varied between days, but they migrated long distance (379–786 m/h) during each observation. The behavior observed in the aquarium tank was categorized into five patterns: schooling, shaking, migrating, spawning, and feeding. Shaking and spawning were observed during one of three observation days. Discussion The present study firstly clarified the small-scale but dynamic nocturnal migration pattern of P. schwenkii in nature by a new method using chemical luminescent tags. In addition, combined observations from nature and an aquarium could be used to estimate the behavior of this species. Pempheris schwenkii may reduce their predation risk of eggs and adults by spawning at outer reef in nighttime. It was estimated that they can potentially migrate 4–7 km/night. The rapid growth known for this species may have been supported by their feeding behavior where they can fill up their stomach every night with rich zooplankton in outer reefs. Furthermore, the behavior of this species indicates the possibility that they make an important contribution to the flow of energy and materials in their coral reef ecosystem.

DEVELOPMENT OF A LAND DEGRADATION ASSESSMENT MODEL BASED ON FIELD INDICATORS ASSESSMENT AND PREDICTION METHODS IN WAI SARI, SUB-WATERSHED KAIRATU DISTRICT, WESTERN SERAM REGENCY, MALUKU PROVINCE, INDONESIA

2019 ◽  
Vol 2 (1) ◽  
pp. 071-084
Author(s):  
Silwanus M. Talakua ◽  
Rafael M. Osok
Keyword(s):  
Land Degradation ◽  
Soil Loss ◽  
Assessment Model ◽  
Small Scale ◽  
Small Islands ◽  
Topographic Map ◽  
Field Assessment ◽  
Field Indicators ◽  
Degradation Measurement ◽  
Very High

The study was conducted in Wai Sari sub-watershed, Western Seram Regency Maluku to develop an accurate land degradation assessment model for tropical small islands. The Stocking’s field land degradation measurement and RUSLE methods were applied to estimate soil loss by erosion and the results of both methods were statistically tested in order to obtain a correction factor. Field indicators and prediction data were measured on 95 slope units derived from the topographic map. The rates of soil loss were calculated according to both methods, and the results were used to classify the degree of land degradation. The results show that the degree of land degradation based on the field assessment ranges from none-slight (4.04 - 17.565 t/ha/yr) to very high (235.44 - 404.00 t/ha/yr), while the RUSLE method ranges from none-slight (0.04-4.59 t/ha/yr) to very high 203.90 - 518.13 t/ha/yr.  However, the RUSLE method shows much higher in average soil loss (133.4 t/ha/yr) than the field assessment (33.9 t/ha/yr). The best regression equation of  logD/RP = - 0.594 + 1.0 logK + 1.0 logLS + 1.0 logC or D = 0.2547xRxKxLSx CxP was found to be a more suitable land degradation assessment  model for a small-scale catchment area in the tropical small islands.

scholarly journals Is a spatial investigation possible without long-distance refit/conjoin? Application to the MIS 11 lithic assemblage of levels E and J from La Cansaladeta site (Tarragona, Spain)

2021 ◽  
Vol 13 (9) ◽  
Author(s):  
Görkem Cenk Yeşilova ◽  
Andreu Ollé ◽  
Josep Maria Vergès
Keyword(s):  
Spatial Patterns ◽  
Spatial Information ◽  
Small Dimension ◽  
Middle Pleistocene ◽  
Small Scale ◽  
Spatial Pattern Analysis ◽  
Long Distance ◽  
Great Opportunity ◽  
Density Mapping ◽  
Study Materials

AbstractIn this manuscript, we present the first systematic refitting results of the small-scale Middle Pleistocene (MIS11) rock shelter site of La Cansaladeta. The lithic materials that have been recovered from the archaeological levels E and J were the main study materials. These levels were investigated regarding spatial pattern analysis and analyzed with auxiliary methods such as quantitative density mapping demonstration and technological analysis of the lithic clusters. Thus, the spatial patterns of the two levels were compared and discussed, in terms of connections, clusters, and movement of the lithic elements. Undoubtedly, the well preservation of the archaeological levels offered a great opportunity for the interpretation of the spatial patterns in a high-resolution perspective. La Cansaladeta has not been paid attention adequately so far may be due to the small dimension of the excavation surface or to the scarcity of faunal record. Our results show that small-scale sites without long-distance refit/conjoin connections can provide significant spatial information. Indeed, if the sites have very well-preserved archaeological levels, the absence of long connections can be supported by the auxiliary methods.

scholarly journals Memories of Migrations Past: Sociality and Cognition in Dynamic, Seasonal Environments

2021 ◽  
Vol 9 ◽  
Author(s):  
Eliezer Gurarie ◽  
Sriya Potluri ◽  
George Christopher Cosner ◽  
Robert Stephen Cantrell ◽  
William F. Fagan
Keyword(s):  
Environmental Changes ◽  
Animal Movement ◽  
Spatial Scales ◽  
Rapid Change ◽  
Reference Memory ◽  
Migratory Behavior ◽  
Migration Behavior ◽  
Long Distance ◽  
Trade Offs ◽  
Resource Dynamics

Seasonal migrations are a widespread and broadly successful strategy for animals to exploit periodic and localized resources over large spatial scales. It remains an open and largely case-specific question whether long-distance migrations are resilient to environmental disruptions. High levels of mobility suggest an ability to shift ranges that can confer resilience. On the other hand, a conservative, hard-wired commitment to a risky behavior can be costly if conditions change. Mechanisms that contribute to migration include identification and responsiveness to resources, sociality, and cognitive processes such as spatial memory and learning. Our goal was to explore the extent to which these factors interact not only to maintain a migratory behavior but also to provide resilience against environmental changes. We develop a diffusion-advection model of animal movement in which an endogenous migratory behavior is modified by recent experiences via a memory process, and animals have a social swarming-like behavior over a range of spatial scales. We found that this relatively simple framework was able to adapt to a stable, seasonal resource dynamic under a broad range of parameter values. Furthermore, the model was able to acquire an adaptive migration behavior with time. However, the resilience of the process depended on all the parameters under consideration, with many complex trade-offs. For example, the spatial scale of sociality needed to be large enough to capture changes in the resource, but not so large that the acquired collective information was overly diluted. A long-term reference memory was important for hedging against a highly stochastic process, but a higher weighting of more recent memory was needed for adapting to directional changes in resource phenology. Our model provides a general and versatile framework for exploring the interaction of memory, movement, social and resource dynamics, even as environmental conditions globally are undergoing rapid change.

scholarly journals A Research of Construction Mechanism of Vassal State’s City Group during Spring and Autumn Period Based on the Analyzation of Geographic Image – Take south region of Shandong as example

2015 ◽  
Vol XL-5/W7 ◽  
pp. 151-157
Author(s):  
X. Gao ◽  
B. Li ◽  
X. Zhou
Keyword(s):  
Geographical Location ◽  
Small Scale ◽  
Topographic Map ◽  
Autumn Period ◽  
Economic Support ◽  
Independent Unit ◽  
Spring And Autumn Period ◽  
Space Layout ◽  
The One ◽  
Agricultural Areas

Spring and Autumn period, the vassal states began to carry out country defense construction actively, brought changes to building the ideological. At that time, the south region of Shandong, as an independent unit of geography, seldom affected by external factors, and had striking cultural characteristics. Vassal states there constructed their capital mainly to defense the neighboring countries and cope with small scale mergers war, not involving the nationwide military deployment. Therefore, the region reflect the construction thought changes during the Spring and Autumn Period, and consistent with the research purpose. Based on this judgment, the author analyzed each capital’s location and terrain feature by topographic map. In brief, the Spring and Autumn Period, feudal states acted of one's own free will, the relationship between cities contained the one within and between vassal states. Within vassal state relationships included economic support, entrenching each other and protecting the country together. Meanwhile, strategic defensing, scrambling for resources and geographical location comprised of the competition between vassal states. In the agrarian age, the political centers and agricultural areas were interdependent, giving priority to the development of political cities. Transformation of capitals’ space layout was actually the process of carving up farming plains, the powerful states occupy favorable geographical position, and the small countries would be encroached and annexed gradually.

scholarly journals ‘Disperse abroad in the land’: the role of wildlife in the dissemination of antimicrobial resistance

2016 ◽  
Vol 12 (8) ◽  
pp. 20160137 ◽  
Author(s):  
Kathryn E. Arnold ◽  
Nicola J. Williams ◽  
Malcolm Bennett
Keyword(s):  
Antimicrobial Resistance ◽  
Natural Environment ◽  
High Throughput Sequencing ◽  
Small Scale ◽  
Human Populations ◽  
Long Distance ◽  
Antimicrobial Drugs ◽  
Clinical Resistance ◽  
Wildlife Populations ◽  
The Impact

Antimicrobial resistance (AMR) has been detected in the microbiota of many wildlife species, including long-distance migrants. Inadequately treated wastes from humans and livestock dosed with antimicrobial drugs are often assumed to be the main sources of AMR to wildlife. While wildlife populations closely associated with human populations are more likely to harbour clinically important AMR related to that found in local humans and livestock, AMR is still common in remote wildlife populations with little direct human influence. Most reports of AMR in wildlife are survey based and/or small scale, so researchers can only speculate on possible sources and sinks of AMR or the impact of wildlife AMR on clinical resistance. This lack of quantitative data on the flow of AMR genes and AMR bacteria across the natural environment could reflect the numerous AMR sources and amplifiers in the populated world. Ecosystems with relatively simple and well-characterized potential inputs of AMR can provide tractable, but realistic, systems for studying AMR in the natural environment. New tools, such as animal tracking technologies and high-throughput sequencing of resistance genes and mobilomes, should be integrated with existing methodologies to understand how wildlife maintains and disperses AMR.

Roman Seas

2020 ◽  
Author(s):  
Justin Leidwanger
Keyword(s):  
Late Antiquity ◽  
Economic Life ◽  
Small Scale ◽  
Long Distance ◽  
New Approach ◽  
Landscape Studies ◽  
Single Well ◽  
Multiple Structures ◽  
Archaeological Analysis

This book offers an archaeological analysis of maritime economy and connectivity in the Roman east. That seafaring was fundamental to prosperity under Rome is beyond doubt, but a tendency to view the grandest long-distance movements among major cities against a background noise of small-scale, short-haul activity has tended to flatten the finer and varied contours of maritime interaction and coastal life into a featureless blue Mediterranean. Drawing together maritime landscape studies and network analysis, this work takes a bottom-up view of the diverse socioeconomic conditions and seafaring logistics that generated multiple structures and scales of interaction. The material record of shipwrecks and ports along a vital corridor from the southeast Aegean across the northeast Mediterranean provides a case study of regional exchange and communication based on routine sails between simple coastal facilities. Rather than a single well-integrated and persistent Mediterranean network, multiple discrete and evolving regional and interregional systems emerge. This analysis sheds light on the cadence of economic life along the coast, the development of market institutions, and the regional continuities that underpinned integration—despite certain interregional disintegration—into Late Antiquity. Through this model of seaborne interaction, the study advances a new approach to the synthesis of shipwreck and other maritime archaeological and historical economic data, as well as a path through the stark dichotomies that inform most paradigms of Roman connectivity and trade.

Systematics and Paleoecology of Norian (Late Triassic) Bivalves from a Tropical Island Arc: Wallowa Terrane, Oregon

1987 ◽  
Vol 61 (S22) ◽  
pp. 1-83 ◽  
Author(s):  
Cathryn R. Newton ◽  
Michael T. Whalen ◽  
Joel B. Thompson ◽  
Nienke Prins ◽  
David Delalla
Keyword(s):  
North American ◽  
Island Arc ◽  
Late Triassic ◽  
Small Scale ◽  
Long Distance ◽  
Tropical Island ◽  
North American Cordillera ◽  
The North ◽  
Wallowa Terrane ◽  
Hells Canyon

Early Norian silicified bivalves from Hells Canyon in the Wallowa terrane of northeastern Oregon are part of a rich molluscan biota associated with a tropical island arc. The Hells Canyon locality preserves lenses of silicified shells formed as tempestites in a shallow subtidal carbonate environment. These shell assemblages are parautochthonous and reflect local, rather than long-distance, transport. Silicification at this locality involved small-scale replacement of original calcareous microstructures, or small-scale replacement of neomorphosed shells, without an intervening phase of moldic porosity. This incremental replacement of carbonate by silica contrasts markedly with void-filling silicification textures reported previously from silicified Permian bivalve assemblages.The bivalve paleoecology of this site indicates a suspension feeding biota existing on and within the interstices of coral-spongiomorph thickets, and inhabiting laterally adjacent substrates of peloidal carbonate sand. The bivalve fauna is ecologically congruent with the reef-dwelling molluscs associated with Middle Triassic sponge-coral buildups in the Cassian Formation of the Dolomites (Fuersich and Wendt, 1977). Hells Canyon is a particularly important early Norian locality because of the diversity of substrate types and because the site includes many first occurrences of bivalves in the North American Cordillera. These first occurrences include the first documentation of the important epifaunal families Pectinidae and Terquemiidae in Triassic rocks of the North American Cordillera.The large number of biogeographic and geochronologic range extensions discovered in this single tropical Norian biota indicates that use of literature-based range data for Late Triassic bivalves may be very hazardous. Many bivalve taxa formerly thought to have gone extinct in Karnian time have now been documented from Norian strata in this arc terrane. These range extensions, coupled with the high bivalve species richness of the Hells Canyon site, suggest that the Karnian mass extinction in several literature-based compilations may be an artifact of incomplete sampling. Even for the Norian, present compilations of molluscan extinction may have an unacceptably large artifactual component.Thirty-five bivalve taxa from the Hells Canyon locality are discussed. Of these, seven are new: the mytilid Mysidiella cordillerana n. sp., the limacean Antiquilima vallieri n. sp., the true oyster Liostrea newelli n. sp., the pectinacean Crenamussium concentricum n. gen. and sp., the unioid Cardinioides josephus n. sp., the trigoniacean Erugonia canyonensis n. gen. and sp., and the carditacean Palaeocardita silberlingi n. sp.

scholarly journals Failure Mechanism of Rock Bridge Based on Acoustic Emission Technique

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Guoqing Chen ◽  
Yan Zhang ◽  
Runqiu Huang ◽  
Fan Guo ◽  
Guofeng Zhang
Keyword(s):  
Acoustic Emission ◽  
Failure Mechanism ◽  
High Speed ◽  
Large Scale ◽  
Small Scale ◽  
Failure Behavior ◽  
Long Distance ◽  
Rock Bridge ◽  
Rocky Slope ◽  
Landslide Model

Acoustic emission (AE) technique is widely used in various fields as a reliable nondestructive examination technology. Two experimental tests were carried out in a rock mechanics laboratory, which include (1) small scale direct shear tests of rock bridge with different lengths and (2) large scale landslide model with locked section. The relationship of AE event count and record time was analyzed during the tests. The AE source location technology and comparative analysis with its actual failure model were done. It can be found that whether it is small scale test or large scale landslide model test, AE technique accurately located the AE source point, which reflected the failure generation and expansion of internal cracks in rock samples. Large scale landslide model with locked section test showed that rock bridge in rocky slope has typical brittle failure behavior. The two tests based on AE technique well revealed the rock failure mechanism in rocky slope and clarified the cause of high speed and long distance sliding of rocky slope.

Managing Spread from Rhizome Fragments is Key to Reducing Invasiveness in Miscanthus × giganteus

2014 ◽  
Vol 7 (3) ◽  
pp. 517-525 ◽  
Author(s):  
Natalie M. West ◽  
David P. Matlaga ◽  
Adam S. Davis
Keyword(s):  
Agricultural Landscape ◽  
Propagule Pressure ◽  
Ecological Integrity ◽  
Low Risk ◽  
Small Scale ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Biofuel Crops ◽  
Combining Data ◽  
Field Edge

AbstractMiscanthus × giganteus, a widely planted biofeedstock, is generally regarded as a relatively low invasion concern. As a seed-infertile species, it lacks a consistent mechanism of long-distance dispersal, a key contributor to invasion rate, and constitutes a low risk for cultivation escape. However, agricultural production shelters plants from stochasticity and increases propagule pressure, enhancing the potential for low-risk species to take advantage of rare dispersal opportunities. Weed risk assessments of M. × giganteus assume the rarity of events such as scouring and flooding that would facilitate secondary dispersal of vegetative rhizome fragments and the long-term sexual inviability of escapes. Combining data from small-scale rhizome fragmentation and movement experiments, and estimates from the literature, we parameterized an individual-based model to examine M. × giganteus spread given three dispersal scenarios. We further evaluated our estimates in response to different field edge buffer widths and monitoring intensities, two key strategies advised for containing biofuel crops. We found that clonal expansion from the field edge alone was sufficient to allow the crop to outgrow buffers of 3 m or less within 11 to 15 yr with low monitoring intensities. Further, models that included the possibility of rhizome dispersal from fields and scouring at field edges demonstrate the potential for long-distance dispersal and establishment with inadequate management. Our study highlights the importance of considering minimum enforced management guidelines for growers to maintain the ecological integrity of the agricultural landscape.

Dynamics of a Large Scale Hydraulic Capsule Pipeline System

1999 ◽  
Vol 124 (1) ◽  
pp. 191-195 ◽  
Author(s):  
Hongliu Du ◽  
Satish S. Nair
Keyword(s):  
Large Scale ◽  
Control Method ◽  
Experimental Studies ◽  
Small Scale ◽  
Pipeline System ◽  
Centrifugal Pumps ◽  
Long Distance ◽  
Column Separation ◽  
In Series ◽  
Hydraulic Capsule Pipeline

The dynamics of a booster station, which is critical for the control of a novel, long distance, hydraulic capsule pipeline, is simulated mathematically for design studies and control of the hydraulic transients caused by the valve actuators in the system. Several modifications to the pump bypass station configuration of the booster station have been studied. With the objective of eliminating column separation and reducing flow reversals, a configuration with several centrifugal pumps connected in series, and a carefully sized air chamber is found to be a viable design. A valve control method is designed to eliminate column separation and the design results in acceptable flow reversal levels in the main pipe. The simulation results match with trends in limited experimental studies performed on a small scale experimental capsule pipeline system.

Sign in / Sign up

Export Citation Format

Share Document