The effects of handling time, ambient light, and anaesthetic method, on the standardized measurement of fish colouration

The effects of handling time, ambient light intensity, and anaesthetic method, on the collection of spectral reflectance data were assessed in two species of Malawi cichlids ( Melanochromis auratus and Metriaclima zebra ). Using spectrometry, colour patches were measured over 10 min, under increasing ambient light levels, and using three anaesthetic methods. As time elapsed, maximum percent reflectance (Rmax) decreased across all anaesthetic methods and species, suggesting that measurements should be taken immediately after capture and anaesthetization. With increasing light intensity, Rmax increased significantly, suggesting that measurements should be taken under natural ambient conditions when possible. Finally, we found that anaesthetizing fish using an ice bath produced significantly higher Rmax than using either MS-222 (tricaine methanesulphonate) or clove oil (eugenol). However, the highest proportion of ultraviolet (UV) colouration was recorded while fish were anaesthetized with clove oil. Our results highlight the variation involved in measuring fish colour patterns using two related species, and thus indicate the need for a standardized approach to collecting spectral reflectance data in fish.

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Optimizing rearing and welfare in Senegalese sole (Solea senegalesensis) broodstock: Effect of ambient light intensity and handling time on stress response

Applied Animal Behaviour Science ◽

10.1016/j.applanim.2019.104880 ◽

2020 ◽

Vol 222 ◽

pp. 104880 ◽

Cited By ~ 1

Author(s):

Filipe Figueiredo ◽

Cláudia Aragão ◽

Wilson Pinto ◽

Maria Teresa Dinis ◽

Catarina C.V. Oliveira

Keyword(s):

Stress Response ◽

Light Intensity ◽

Handling Time ◽

Senegalese Sole ◽

Ambient Light

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100 ROLE OF LIGHT INTENSITY IN THE DEVELOPMENT OF OSTRICH FERN

HortScience ◽

10.21273/hortsci.29.5.442e ◽

1994 ◽

Vol 29 (5) ◽

pp. 442e-442 ◽

Cited By ~ 1

Author(s):

Matthew Donelan ◽

Kenneth Corey

Keyword(s):

Light Intensity ◽

High Light ◽

Silt Loam ◽

Ambient Conditions ◽

Light Levels ◽

Shade Cloth ◽

Growth Development ◽

Role Of Light ◽

Frond Length

Crowns of ostrich fern (Matteuccia struthiopteris L. Todaro) were field-planted in June 1993 on a Hadley silt loam in South Deerfield, Mass. Shade cloth was used to alter light intensity to determine if light intensity effects growth and development of fronds and crowns. Light levels were 22% (low), 45% (intermediate), 72% (high), and 100% (full) of ambient conditions. Survival of crowns decreased with increasing light intensity with only 22% survival under full light. Low, intermediate, and high light levels resulted in 89%, 75%, and 56%, respectively, of crowns producing shoots. Light intensity did not effect the number or length of fronds produced. Frond length reached a maximum after 2 months growth. Development of secondary crowns was enhanced at intermediate and high light intensities. Final crown weight was significantly correlated with initial crown weight regardless of light intensity. Crowns will be vernalized and forced hydroponically to determine effects of light intensity and crown size on growth of croziers.

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Photo-dependent population dynamics of Stentor coeruleus and its consumption of Colpidium striatum

Canadian Journal of Zoology ◽

10.1139/z07-044 ◽

2007 ◽

Vol 85 (5) ◽

pp. 674-677 ◽

Cited By ~ 3

Author(s):

M.W. Cadotte ◽

S. Jantz ◽

D.V. Mai

Keyword(s):

Light Intensity ◽

High Light Intensity ◽

Light Treatment ◽

High Light ◽

Ambient Light ◽

Population Responses ◽

Physiological Processes ◽

Light Levels ◽

Stentor Coeruleus ◽

Predator System

The predatory protozoan Stentor coeruleus Ehrenberg, 1830 is known to show photosensitivity and photodispersion, avoiding regions of high light intensity as an antipredation strategy. This physiological and behavioral response to light likely has demographic consequences. We manipulated light intensity to determine population responses of S. coeruleus and the resulting effects on its prey Colpidium striatum Stokes, 1886. We show that S. coeruleus maintained the highest population density under ambient light levels and low densities under both high and no light treatments. The results from the no light treatment were surprising because little work has been done on possible important behavioral and physiological processes cued by light. These results add power to the use of S. coeruleus as a model predator system to test ecological dynamics and processes associated with predation.

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Ambient light intensity and direction determine relative attractiveness of yellow traps toRhagoletis indifferens(Diptera: Tephritidae)

The Canadian Entomologist ◽

10.4039/tce.2015.6 ◽

2015 ◽

Vol 147 (6) ◽

pp. 776-786 ◽

Cited By ~ 4

Author(s):

W.L. Yee

Keyword(s):

Light Intensity ◽

Fruit Fly ◽

Ambient Light ◽

Laboratory Results ◽

Yellow Traps ◽

Relative Attractiveness ◽

Variable Light ◽

Sunlight Intensity ◽

Trap Placement ◽

Tephritid Fruit Flies

AbstractUnderstanding factors that influence attraction of tephritid fruit flies (Diptera: Tephritidae) to objects can lead to development of more sensitive traps for fly detection. Here, the objective was to determine if differences in attractiveness between two sticky yellow rectangle traps to western cherry fruit fly,Rhagoletis indifferensCurran, depend on ambient light intensity and direction. The translucent plastic Yellow Sticky Strip (YSS) was compared with the less translucent yellow cardboard Alpha Scents (AS). Flies were released inside a box or cage opposite a trap or traps illuminated from outside at different intensities to generate variable light passage. Regardless of type, the trap with greatest light passage was most attractive. When the same light intensity was shone on both traps, the YSS, which allowed greater light passage, was more attractive than the AS. When the light was inside a cage and shone onto the two traps in the same direction as approaching flies, the AS reflected more light and was more attractive. A field experiment generally supported light passage effects seen in the laboratory. Results suggest trap placement with respect to sunlight intensity and direction affects light passage and the attractiveness of yellow traps toR. indifferens.

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Inhibition of Primary Photosynthesis in Desiccating Antarctic Lichens Differing in Their Photobionts, Thallus Morphology, and Spectral Properties

Microorganisms ◽

10.3390/microorganisms9040818 ◽

2021 ◽

Vol 9 (4) ◽

pp. 818

Author(s):

Miloš Barták ◽

Josef Hájek ◽

Alla Orekhova ◽

Johana Villagra ◽

Catalina Marín ◽

...

Keyword(s):

Spectral Reflectance ◽

Quantum Yields ◽

Specific Response ◽

Variable Fluorescence ◽

Protective Mechanisms ◽

Quenching Analysis ◽

Relative Water ◽

Species Specific ◽

Kinetics Of ◽

Reflectance Data

Five macrolichens of different thallus morphology from Antarctica (King George Island) were used for this ecophysiological study. The effect of thallus desiccation on primary photosynthetic processes was examined. We investigated the lichens’ responses to the relative water content (RWC) in their thalli during the transition from a wet (RWC of 100%) to a dry state (RWC of 0%). The slow Kautsky kinetics of chlorophyll fluorescence (ChlF) that was recorded during controlled dehydration (RWC decreased from 100 to 0%) and supplemented with a quenching analysis revealed a polyphasic species-specific response of variable fluorescence. The changes in ChlF at a steady state (Fs), potential and effective quantum yields of photosystem II (FV/FM, ΦPSII), and nonphotochemical quenching (NPQ) reflected a desiccation-induced inhibition of the photosynthetic processes. The dehydration-dependent fall in FV/FM and ΦPSII was species-specific, starting at an RWC range of 22–32%. The critical RWC for ΦPSII was below 5%. The changes indicated the involvement of protective mechanisms in the chloroplastic apparatus of lichen photobionts at RWCs of below 20%. In both the wet and dry states, the spectral reflectance curves (SRC) (wavelength 400–800 nm) and indices (NDVI, PRI) of the studied lichen species were measured. Black Himantormia lugubris showed no difference in the SRCs between wet and dry state. Other lichens showed a higher reflectance in the dry state compared to the wet state. The lichen morphology and anatomy data, together with the ChlF and spectral reflectance data, are discussed in relation to its potential for ecophysiological studies in Antarctic lichens.

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