Spatial partitioning in the use of structural woody habitat supports the cohabitation of two cod species in a large lowland river

2016 ◽  
Vol 67 (12) ◽  
pp. 1835 ◽  
Author(s):  
J. A. Lieschke ◽  
J. P. Lyon ◽  
P. D. Moloney ◽  
S. J. Nicol
Keyword(s):  
Lowland River ◽  
Specific Interactions ◽  
Negative Consequences ◽  
Catch Per Unit Effort ◽  
Spatial Partitioning ◽  
Murray River ◽  
Eastern Australia ◽  
The Common ◽  
Species Specific ◽  
Murray Cod

Many freshwater fish worldwide have been shown to use Structural Woody Habitat (SWH) for a variety of reasons. The mid reaches of the Murray River, a large lowland river in south-eastern Australia, was surveyed by boat electrofishing, to investigate the use of SWH type (hollows, rootmass and solids), SWH distance to bank (near bank, intermediate to bank and mid-channel) and the interaction between SWH type and distance to bank. The study found that Murray cod catch per unit effort (CPUE) increased in near-bank areas when hollows were a component of the SWH. The CPUE of trout cod was higher when hollows were present. However, the interactions between distance to bank and hollow SWH were complex and dependent on presence or absence of rootmass. The species-specific interactions between SWH microhabitat and distance to bank found within this study has important relevance for stream managers. The common practice of realigning SWH favours Murray cod over trout cod, which could have negative consequences for the endangered trout cod. More broadly, managers may need to consider a balance of SWH type and where it is placed in the river for the species they are targeting when rehabilitating rivers via the introduction of SWH.

Effects of tag type, morphological location and tagger experience on tag retention rates in freshwater fishes

2019 ◽  
Vol 70 (6) ◽  
pp. 891
Author(s):  
Jarod P. Lyon ◽  
Robin Hale ◽  
Adrian Kitchingman ◽  
Justin O'Connor ◽  
Joanne Sharley ◽  
...  
Keyword(s):  
Conservation Management ◽  
Retention Rates ◽  
Lowland River ◽  
Passive Integrated Transponder ◽  
Tag Retention ◽  
Eastern Australia ◽  
Murray Cod ◽  
Pit Tagging ◽  
River Fish ◽  
Rejection Rates

Mark–recapture of fish is often used to inform fisheries or conservation management. Given that variability in tagging efficiencies can affect estimates of population size, it is important that rates of tag rejection are quantified. We double tagged over 45000 large-bodied, long-lived fish in a turbid lowland river in south-eastern Australia. During yearly recapture fish surveys, data on tag rejection were collected. We found that the probability of tag rejection varied as a function of fish species, tag type and tagger experience. Floy tags were more likely to be rejected as dart tags in large-bodied golden perch Macquaria ambigua (6 and 3% respectively), silver perch (18 and 4% respectively) and trout cod (19 and 7% respectively), whereas rates of rejection in the large-bodied Murray cod Maccullochella peelii were similar for both tag types (12 and 10% respectively). More experienced taggers had lower rates of rejection, which varied between 1 and 48% for individual taggers. We trialled three morphological locations for passive integrated transponder (PIT) tagging of fish, with rejection rates lowest for tags implanted in the stomach cavity and highest for those implanted in the pectoral musculature. This study presents the first tag rejection rates for dart, floy and PIT tags for lowland Australian river fish, information that can help guide future monitoring programs.

scholarly journals Comparative habitat use by large riverine fishes

2014 ◽  
Vol 65 (2) ◽  
pp. 164 ◽  
Author(s):  
John D. Koehn ◽  
Simon J. Nicol
Keyword(s):  
Surface Water ◽  
River Channel ◽  
Microhabitat Use ◽  
Radio Tracking ◽  
River Bank ◽  
Habitat Patches ◽  
Murray River ◽  
Eastern Australia ◽  
Carp Cyprinus Carpio ◽  
Murray Cod

The present radio-tracking study compared adult daytime microhabitat use by three large Australian native freshwater fishes (Murray cod, Maccullochella peelii, trout cod, M. macquariensis, golden perch, Maquaria ambigua) and introduced carp, Cyprinus carpio, in the Murray River, south-eastern Australia. The paper describes habitat patches used by all species and quantifies differences among species. All species were strongly associated with structural woody habitat (>68% cover), deeper (>2.4 m), slower water (<0.2 m s–1) closer to the river bank, with variations in substrate. Murray cod and trout cod used deeper habitats (2.8 m and 2.9 m, respectively), with higher surface water velocities (0.37 m s–1 and 0.49 m s–1, respectively) and further from the bank than the habitats of golden perch (2.6 m; 0.31 m s–1) or carp (2.4 m; 0.20 m s–1), the latter species using wood higher in the water column than did cod species. Trout cod used habitats furthest from the bank and carp those closest. These data provide support and direction for reintroduction of structural woody habitat patches for rehabilitation which, in general, should have >70% cover, be >1.5 m high, located <15% of the river channel (width) closest to the bank, with surface water velocities of 0.3–0.6 m s–1.

scholarly journals Correcting density-dependent effects in abundance estimates from bottom-trawl surveys

2014 ◽  
Vol 71 (5) ◽  
pp. 1107-1116 ◽  
Author(s):  
Stan Kotwicki ◽  
James N. Ianelli ◽  
André E. Punt
Keyword(s):  
Stock Assessment ◽  
Dead Zone ◽  
Walleye Pollock ◽  
Assessment Model ◽  
Bottom Trawl ◽  
Trawl Survey ◽  
Negative Consequences ◽  
Catch Per Unit Effort ◽  
Density Dependent ◽  
Index Of Abundance

Abstract Indices of abundance are important for estimating population trends in stock assessment and ideally should be based on fishery-independent surveys to avoid problems associated with the hyperstability of the commercial catch per unit effort (cpue) data. However, recent studies indicate that the efficiency of the survey bottom trawl (BT) for some species can be density-dependent, which could affect the reliability of survey-derived indices of abundance. A function qe∼f(u), where qe is the BT efficiency and u the catch rate, was derived using experimentally derived acoustic dead-zone correction and BT efficiency parameters obtained from combining a subset of BT catch data with synchronously collected acoustic data from walleye pollock (Theragra chalcogramma) in the eastern Bering Sea (EBS). We found that qe decreased with increasing BT catches resulting in hyperstability of the index of abundance derived from BT survey. Density-dependent qe resulted in spatially and temporarily variable bias in survey cpue and biased population age structure derived from survey data. We used the relationship qe∼f(u) to correct the EBS trawl survey index of abundance for density-dependence. We also obtained a variance–covariance matrix for a new index that accounted for sampling variability and the uncertainty associated with the qe. We found that incorporating estimates of the new index of abundance changed outputs from the walleye pollock stock assessment model. Although changes were minor, we advocate incorporating estimates of density-dependent qe into the walleye pollock stock assessment as a precautionary measure that should be undertaken to avoid negative consequences of the density-dependent qe.

Dark side of instant messaging: an empirical investigation from technology and society perspective

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sheshadri Chatterjee ◽  
Ranjan Chaudhuri ◽  
Demetris Vrontis
Keyword(s):  
Instant Messaging ◽  
Dark Side ◽  
Survey Method ◽  
Negative Consequences ◽  
Common People ◽  
Cross Sectional ◽  
Content Type ◽  
The Common ◽  
Society Perspective ◽  
Unique Study

PurposeThe purpose of this study is to examine the dark side of instant messaging from the technological and societal perspectives.Design/methodology/approachWith the help of literature review and different theories, a model has been developed conceptually. Later the model has been validated using statistical method. The authors have used 304 responses from the survey method, and this sample has been used to statistically validate the conceptual model.FindingsThis paper has been able to explicitly investigate and identify how different instant messaging platforms such as WhatsApp, WeChat in the form of electronic word of mouth (e-WOM) are contributing toward increase of mob lynching cases. The paper also highlights the important to have effective and enforceable regulation to regulate instant messaging services to the citizens.Research limitations/implicationsThe findings cannot be generalized as the data is collected from India only. Moreover, the study is cross-sectional in nature. To get the comprehensive results, a longitudinal study needs to be conducted. This study considered seven constructs with one moderator. Having more predictors with other boundary conditions might have increased the explanative power of the model.Practical implicationsInstant messaging platforms such as WhatsApp, WeChat and so on are disseminating quick unverified information to the common people. This information sometimes is disseminated in inappropriate and exaggerated forms. This makes the instant messaging (WhatsApp) users' sentiment readily heated in some cases. They take such an action as mob lynching. This study determines the predictors of mob lynching along with the moderator impact of instant messaging in the society.Originality/valueThere are only a few studies those have explored the dark side of instant messaging. The proposed theoretical model is a unique model, which shows the predictors of mob lynching along with the negative consequences of the instant messaging (WhatsApp) in the society. From this perspective, this study can be considered as a unique study.

Morphology, physiology and AFLP markers validate that green box is a hybrid of Eucalyptus largiflorens and E. gracilis (Myrtaceae)

2013 ◽  
Vol 26 (2) ◽  
pp. 156 ◽  
Author(s):  
Georgia R. Koerber ◽  
Peter A. Anderson ◽  
Jack V. Seekamp
Keyword(s):  
Nitrogen Isotope ◽  
Aflp Markers ◽  
Putative Hybrid ◽  
Hybrid Index ◽  
Length Polymorphisms ◽  
Murray River ◽  
Species Specific ◽  
Mature Stands ◽  
Physiological Characters ◽  
Green Box

Prolonged drought and salinity on the Chowilla floodplain of the Murray River have caused deterioration of E. largiflorens F.Muell. A putative hybrid with E. gracilis F.Muell, green box, withstands the saline conditions. We aimed to substantiate that green box is a hybrid and to test for agreement between morphological and physiological characters with amplified fragment length polymorphisms (AFLP). Mature stands were measured for leaf, trunk, floral, cotyledon, carbon and nitrogen isotope discrimination, specific leaf area (SLA) and AFLP. Green box was placed between E. largiflorens and E. gracilis according to categorical principal components analysis (CATPCA) of 21 morphological and physiological characters and character states. The hybrid index of 11 AFLP markers that were 78% species specific separated E. gracilis and E. largiflorens, and the majority of green box plants displayed indices ranging from 0.42 to 0.53, reflecting mostly additive inheritance. Calculation of the hybrid index with all 232 AFLP markers, using maximum likelihood, similarly placed green box between E. gracilis and E. largiflorens. Our morphological, physiological and AFLP-marker observations substantiated that green box is a hybrid between E. largiflorens and E. gracilis.

scholarly journals The effect of water level on lateral movements of fish between river and off-channel habitats and implications for management

2010 ◽  
Vol 61 (3) ◽  
pp. 271 ◽  
Author(s):  
Jarod Lyon ◽  
Ivor Stuart ◽  
David Ramsey ◽  
Justin O'Mahony
Keyword(s):  
Water Level ◽  
Fish Community ◽  
Life History Strategy ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Main River Channel ◽  
Murray River ◽  
Wetland Biodiversity ◽  
Eastern Australia ◽  
Riverine Wetland

Off-channel habitats, such as wetlands and backwaters, are important for the productivity of river systems and for many species of native fish. This study aimed to investigate the fish community, timing and cues that stimulated movement to and from off-channel habitats in the highly regulated Lake Hume to Lake Mulwala reach of the Murray River, south-eastern Australia. In 2004–05, 193 712 fish were collected moving bi-directionally between a 50-km section of the Murray River and several off-channel habitats. Lateral fish movements approximated water level fluctuations. Generally as water levels rose, fish left the main river channel and moved into newly flooded off-channel habitats; there was bi-directional movement as water levels peaked; on falling levels fish moved back to the permanent riverine habitats. Fish previously classified as ‘wetland specialists’, such as carp gudgeons (Hypseleotris spp.), have a more flexible movement and life-history strategy including riverine habitation. The high degree of lateral movement indicates the importance of habitat connectivity for the small-bodied fish community. Wetlands adjacent to the Murray River are becoming increasingly regulated by small weirs and ensuring lateral fish movement will be important in maintaining riverine-wetland biodiversity.

scholarly journals Why Only People and Apes are Ill with Common Cold? The Possible Role of Chromosomal Q-Heterochromatin Variability

2016 ◽  
Vol 6 (1) ◽  
pp. 11
Author(s):  
A. I. Ibraimov
Keyword(s):  
Common Cold ◽  
Standard Theory ◽  
Negative Consequences ◽  
Circulatory Disturbance ◽  
Sickness Rate ◽  
The Common ◽  
And Gender ◽  
Virus Strains ◽  
Body Heat

<p class="1Body">Common cold (CC) is referred to the most widespread human illnesses and affects people all over the globe. Till now there is no standard theory explaining the development mechanism(s) of СС. The etiology of the CC is known - over 200 virus strains are implicated in the cause of the common cold; the rhinoviruses are the most common. As for pathogenesis, it is conventional, that cold plays the important role in development of СС. It is believed that cooling causes blood circulatory disturbance and permeability of vessels that consequently deteriorates the tissue nutrition and its resistance against infectious agents, and its resistibility in relation to infection. It is also known that the CC sickness rate is affected by the age (children get sick more often than adults) and gender (male individuals are more susceptible to CC than females, regardless of their age). Among the issues that have not received an answer is another question: why CC affects only upon humans and apes? It is hypothesized that the cause of these higher primates susceptibility to CC is the highest level of their body heat conductivity in the animal world. Just this circumstance contributes to the rapid and deep cooling of the bodies of people and apes when it is cold, with all the ensuing negative consequences for the organism.</p>

scholarly journals Comparing the folding landscapes of evolutionarily divergent procaspase-3

2022 ◽  
Author(s):  
Liqi Yao ◽  
Clay Clark
Keyword(s):  
Conformational Change ◽  
Common Ancestor ◽  
Folding Pathway ◽  
Free Energies ◽  
Folding Intermediates ◽  
Effector Caspases ◽  
The Common ◽  
Ph Dependent ◽  
Species Specific ◽  
Dimeric Intermediate

All caspases evolved from a common ancestor and subsequently developed into two general classes, inflammatory or apoptotic caspases. The caspase-hemoglobinase fold has been conserved throughout nearly one billion years of evolution and is utilized for both the monomeric and dimeric subfamilies of apoptotic caspases, called initiator and effector caspases, respectively. We compared the folding and assembly of procaspase-3b from zebrafish to that of human effector procaspases in order to examine the conservation of the folding landscape. Urea-induced equilibrium folding/unfolding of procaspase-3b showed a minimum three-state folding pathway, where the native dimer isomerizes to a partially folded dimeric intermediate, which then unfolds. A partially folded monomeric intermediate observed in the folding landscape of human procaspase-3 is not well-populated in zebrafish procaspase-3b. By comparing effector caspases from different species, we show that the effector procaspase dimer undergoes a pH-dependent conformational change, and that the conformational species in the folding landscape exhibit similar free energies. Together, the data show that the landscape for the caspase-hemoglobinase fold is conserved, yet it provides flexibility for species-specific stabilization or destabilization of folding intermediates resulting in changes in stability. The common pH-dependent conformational change in the native dimer, which yields an enzymatically inactive species, may provide an additional, albeit reversible, mechanism for controlling caspase activity in the cell.

Structural analysis of a shrimp thymidylate synthase reveals species-specific interactions with dUMP and raltitrexed

2020 ◽  
Vol 38 (6) ◽  
pp. 1891-1899
Author(s):  
Changshui Liu ◽  
Kun Zang ◽  
Shihao Li ◽  
Fuhua Li ◽  
Qingjun Ma
Keyword(s):  
Structural Analysis ◽  
Thymidylate Synthase ◽  
Specific Interactions ◽  
Species Specific
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