An increase in habitat complexity reduces aggression and monopolization of food by zebra fish (Danio rerio)

1998 ◽  
Vol 76 (4) ◽  
pp. 770-772 ◽  
Author(s):  
Seán P Basquill ◽  
James WA Grant
Keyword(s):  
Danio Rerio ◽  
Coefficient Of Variation ◽  
Habitat Complexity ◽  
Structural Complexity ◽  
Zebra Fish ◽  
Resource Monopolization ◽  
Dominant Fish ◽  
The Relationship ◽  
Complex Habitat

We tested the predictions that an increase in the structural complexity of a habitat causes both a decrease in aggression and the monopolization of resources. Groups of three zebra fish (Danio rerio) were allowed to compete for food in a complex habitat with simulated vegetation and in a simple habitat with no vegetation. As predicted, both the levels of aggression by the dominant fish (P = 0.050) and the coefficient of variation of the amount of food eaten within a group (P = 0.020), a measure of food monopolization, were lower in the complex habitat than in the simple one. Fish that chased competitors more frequently ate more food in both habitats, but the relationship was stronger in the simple than in the complex habitat. Our results suggest that aggression is less useful as a mode of competition in habitats with greater structural complexity. Manipulating the structural complexity of the habitat may be a practical way of controlling the intensity of aggression and resource monopolization in groups of animals.

Monopolization of food by zebrafish (Danio rerio) increases in risky habitats

2002 ◽  
Vol 80 (12) ◽  
pp. 2164-2169 ◽  
Author(s):  
Ian M Hamilton ◽  
Lawrence M Dill
Keyword(s):  
Danio Rerio ◽  
Coefficient Of Variation ◽  
Perceived Risk ◽  
Open Habitat ◽  
Risk Of Predation ◽  
Resource Monopolization

Dominant zebrafish (Danio rerio) previously have been shown to reduce their monopolization of food when foraging in structurally complex habitats compared with open habitats. Complex habitats may be more difficult to defend but may also be safer. To decouple these effects, we compared aggression and monopolization of food in groups of zebrafish foraging in an open habitat and one with overhead cover, as well as in an open habitat and a complex (vegetated) habitat. Covered and open habitats should have been equally defendable. In our experiments, fish used covered habitats more than open ones, suggesting that the perceived risk of predation was lower in covered habitats. There was no difference in use of vegetated and open habitats, suggesting that these habitats, which should differ in defendability, did not differ in safety. We found that the degree of food monopolization (expressed in the coefficient of variation within groups) at risky feeders was significantly greater in open habitats than in covered, but not vegetated, habitats. We did not find a difference in aggression between habitats. These results indicate that resource monopolization in groups of zebrafish is greater in risky habitats and support the hypothesis that the lower monopolization of food in complex habitats could result from greater safety in those habitats rather than, or in addition to, the reduction in defendability.

Structural Aspects of Phonological Development

1988 ◽  
Vol 19 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Karen E. Pollock ◽  
Richard G. Schwartz
Keyword(s):  
Clinical Management ◽  
Structural Complexity ◽  
Strong Preference ◽  
Phonological Development ◽  
Structural Position ◽  
Phonological Disorders ◽  
Syllabic Structure ◽  
The Relationship ◽  
Structural Aspects ◽  
Target Words

The relationship between syllabic structure and segmental development was examined longitudinally in a child with a severe phonological disorder. Six speech samples were collected over a 4-year period (3:5 to 7:3). Analyses revealed gradual increases in the complexity and diversity of the syllable structures produced, and positional preferences for sounds within these forms. With a strong preference for [d] and [n] at the beginning of syllables, other consonants appeared first at the end of syllables. Implications for clinical management of phonological disorders include the need to consider both structural position and structural complexity in assessing segmental skills and in choosing target words for intervention.

scholarly journals Understanding the Relationship Between Crown Shape and Size and Structural Complexity of Individual Trees

2020 ◽  
Author(s):  
Ninni Saarinen ◽  
Kim Calders ◽  
Ville Kankare ◽  
Tuomas Yrttimaa ◽  
Samuli Junttila ◽  
...  
Keyword(s):  
Structural Complexity ◽  
Crown Shape ◽  
Individual Trees ◽  
The Relationship ◽  
Shape And Size

Cadmium stress assessment based on the electrocardiogram characteristics of zebra fish (Danio rerio): QRS complex could play an important role

2017 ◽  
Vol 191 ◽  
pp. 236-244 ◽  
Author(s):  
Na Xing ◽  
Lizhen Ji ◽  
Jie Song ◽  
Jingchun Ma ◽  
Shangge Li ◽  
...  
Keyword(s):  
Danio Rerio ◽  
Cadmium Stress ◽  
Zebra Fish ◽  
Qrs Complex ◽  
Stress Assessment

scholarly journals The comparative effects of habitat complexity on faunal assemblages of northern temperate artificial and natural reefs

2009 ◽  
Vol 66 (4) ◽  
pp. 691-698 ◽  
Author(s):  
W. R. Hunter ◽  
M. D. J. Sayer
Keyword(s):  
Habitat Complexity ◽  
Artificial Reef ◽  
Structural Complexity ◽  
Marine Species ◽  
Rocky Reef ◽  
Faunal Assemblages ◽  
Faunal Abundance ◽  
Concrete Blocks ◽  
Belt Transect ◽  
Natural Reefs

Abstract Hunter, W. R., and Sayer, M. D. J. 2009. The comparative effects of habitat complexity on faunal assemblages of northern temperate artificial and natural reefs. – ICES Journal of Marine Science, 66: 691–698. Several north temperate marine species were recorded on subtidal hard-substratum reef sites selected to produce a gradient of structural complexity. The study employed an established scuba-based census method, the belt transect. The three types of reef examined, with a measured gradient of increasing structural complexity, were natural rocky reef, artificial reef constructed of solid concrete blocks, and artificial reef made of concrete blocks with voids. Surveys were undertaken monthly over a calendar year using randomly placed fixed rope transects. For a number of conspicuous species of fish and invertebrates, significant differences were found between the levels of habitat complexity and abundance. Overall abundance for many of the species examined was 2–3 times higher on the complex artificial habitats than on simple artificial or natural reef habitats. The enhanced habitat availability produced by the increased structural complexity delivered through specifically designed artificial reefs may have the potential to augment faunal abundance while promoting species diversity.

TOXICITY STUDIES ON SILVER AND COPPER NANOPARTICLES

INDIAN DRUGS ◽  
2018 ◽  
Vol 55 (09) ◽  
pp. 58-60
Author(s):  
P Samuel ◽  
◽  
B Pavithra ◽  
R. Priyadarshini ◽  
V. Maheswari ◽  
...  
Keyword(s):  
Atomic Absorption ◽  
Copper Nanoparticles ◽  
Silver Nanoparticle ◽  
Danio Rerio ◽  
Atomic Absorption Spectroscopy ◽  
Pilot Scale ◽  
Zebra Fish ◽  
Ventral Region ◽  
Plant Sources

In a pilot scale study, silver and copper nanoparticles were synthesized from two different plant sources viz Flacourtia indica and Prosopsis juliflora. The in vivo toxicity of silver and copper nanoparticles was tested on Danio rerio (Zebra fish) under different concentrations (1 ppm, 10 ppm and 100 ppm). Through the investigation, the nanoparticles treated fishes developed with hyper pigmentation in the ventral region. The minimum lethal concentration required to bring lethality caused by silver nanoparticle was 10 ppm whereas for copper nanoparticles it was 1 ppm. Further, the concentration of silver and copper nanoparticles accumulated inside the fish was evaluated by Atomic Absorption Spectroscopy. The in vivo concentration of silver and copper nanoparticles steadily increases with increase in dosage of nanoparticles being tested.

scholarly journals Genotoxic impact of emerging contaminant amoxicillin residue on zebra fish (Danio rerio) embryos

Heliyon ◽  
2020 ◽  
Vol 6 (11) ◽  
pp. e05379
Author(s):  
Jayanta Chowdhury ◽  
Tapan Kumar Mandal ◽  
Sandhimita Mondal
Keyword(s):  
Danio Rerio ◽  
Emerging Contaminant ◽  
Zebra Fish ◽  
Danio Rerio Embryos

Fluorometric Measurement of Aflatoxin Adsorbed on Florisil in Minicolumns

1975 ◽  
Vol 58 (4) ◽  
pp. 757-763 ◽  
Author(s):  
James Velasco
Keyword(s):  
Fluorescence Intensity ◽  
Aflatoxin B1 ◽  
Coefficient Of Variation ◽  
Screening Procedure ◽  
The Relationship

Abstract Filter fluorometers have been adapted to measure the fluorescence intensity of aflatoxin adsorbed on a Florisil layer in minicolumns. The relationship between concentration and intensity is near linear in the aflatoxin range from 10 to 100 ng. Although individual aflatoxin fractions cannot be resolved, since the measure is one of total intensity, fluorometric measurements advance the minicolumn screening procedure to a semiquantitative level. The detection of 1 ng aflatoxin B1 is well within the limits of a filter fluorometer with a photomultiplier detector. A precision, expressed as percent coefficient of variation, ranging from 1.2 to 4.2%, was obtained for standard B1 columns.

Sign in / Sign up

Export Citation Format

Share Document