The influence of temperature on the depth distribution of sympatric Erpobdellidae (Hirudinoidea)

1987 ◽  
Vol 65 (5) ◽  
pp. 1243-1246 ◽  
Author(s):  
T. E. Gates ◽  
Ronald W. Davies
Keyword(s):  
Food Resource ◽  
Spatial Separation ◽  
Thermal Gradients ◽  
Temperature Preference ◽  
Class Differences ◽  
Nephelopsis Obscura ◽  
Size Groups ◽  
Influence Of Temperature On ◽  
Migratory Patterns ◽  
Food Resource Utilization

Inter- and intra-specific differences in the behavioral responses of two sympatric Erpobdellidae, Nephelopsis obscura and Erpobdella punctata, to overall water temperature change and thermal gradients were investigated in the laboratory. The results are compared with the seasonal migratory patterns recorded in lentic field habitats. While temperature preference does act as a directional factor in the spring movements to shallow water, only starved small N. obscura and starved large nonreproductive E. punctata showed a preference for colder temperatures after acclimation to a summer temperature of 20 °C. Thus, other components of the population do not use temperature as a cue for their movements to deeper waters in the autumn. It is suggested that the seasonal differential depth distributions shown by components of both species result in a spatial separation of potential competing size groups complementing the inter- and intra-specific size class differences in food resource utilization and temporal differences in resource allocation already demonstrated.

Thermal modulation of channel catfish intestinal dimensions, BBM fluidity, and glucose transport

1996 ◽  
Vol 270 (5) ◽  
pp. R1037-R1043
Author(s):  
K. L. Houpe ◽  
C. Malo ◽  
P. B. Oldham ◽  
R. K. Buddington
Keyword(s):  
Ictalurus Punctatus ◽  
Channel Catfish ◽  
Brush Border Membrane ◽  
Apical Membrane ◽  
Membrane Vesicles ◽  
Adaptive Responses ◽  
Thermal Modulation ◽  
Temperature Coefficients ◽  
Size Groups ◽  
Influence Of Temperature On

In light of the direct influence of temperature on metabolic rates and dietary loads of ectotherms, intestinal responses were evaluated by measuring 1) dimensions, 2) transapical initial rates of transport using intact tissues and brush-border membrane vesicles (BBMV), and 3) BBMV fluidity using two size groups of channel catfish (Ictalurus punctatus) acclimated to different water temperatures. Intestines of larger fish at 15 degrees C were 23% longer and 61% heavier than those at 30 degrees C. Regardless of assay temperature, rates of glucose uptake by fish held at 30 degrees C relative to those at 15 degrees C were twofold higher for intact tissues and over fivefold higher for BBMV. Although rates of PBMV transport were higher for smaller fish, adaptive responses were greater for larger fish. Temperature coefficients (Q10S) for BBMV transport were higher between 5 and 15 degrees C (3.5-4.5) relative to 15 to 35 degrees C (1.9-2.0) and may be partly related to the inability of catfish held at low temperatures to adjust apical membrane fluidity. Our findings indicate that 1) cold-acclimated catfish maintain transport capacities by increasing intestinal dimensions, 2) high acclimation temperatures increase rates of uptake by as yet unknown mechanisms, 3) thermal modulation of transport varies among species and nutrients, and 4) adaptive responses of ectotherms are different from those of homeotherms).

Laboratory Methods for Determining Temperature Preference

1977 ◽  
Vol 34 (5) ◽  
pp. 749-752 ◽  
Author(s):  
Robert W. McCauley
Keyword(s):  
Temperature Gradient ◽  
Social Interactions ◽  
Physiological State ◽  
Thermal Gradients ◽  
Temperature Preference ◽  
Laboratory Methods ◽  
Preferred Temperature ◽  
Laboratory Techniques ◽  
Different Types ◽  
Temperature Preferences

Different types of temperature-gradient devices used in the laboratory to determine temperature preferences of fish are classified and reviewed. The type of device used seems to have less effect on experimental results than do other variables such as age, size, season, physiological state, or social interactions. Key words: preferred temperature, thermal gradients, thermoregulation, behavioral, gradient devices, laboratory techniques

Independent Distributions of Fish Larvae and Their Prey: Natural Paradox or Sampling Artifact?

1988 ◽  
Vol 45 (1) ◽  
pp. 48-59 ◽  
Author(s):  
Kenneth T. Frank
Keyword(s):  
Larval Fish ◽  
Fish Larvae ◽  
Food Resource ◽  
Zooplankton Biomass ◽  
Data Sets ◽  
Distributional Pattern ◽  
Coarse Mesh ◽  
Larval Food ◽  
Size Groups ◽  
Abundance And Distribution

Several recent studies have concluded that larval fish distributions are independent of the abundance and distribution of their prey. All of these studies used coarse-mesh (> 250 μm) nets, incapable of retaining the edible zooplankton for fish larvae, to provide quantitative estimates of the larval food resource. The assumption that zooplankton captured by coarse-mesh nets provided a reliable index of the edible zooplankton for fish larvae was tested and unsupported by the analysis of several independent data sets. In the waters off southwestern Nova Scotia the biomass of edible zooplankton for young larval fish was highly concentrated in the nearshore region, progressively lower levels were evident offshore on the shelf, and the mesoscale distributional pattern did not accurately reflect the total zooplankton biomass retained by a 333-μm-mesh net. Independent spatial distributions of discrete size groups of zooplankton are characteristics similar to zooplankton distributions reported for other geographic regions. A more logical explanation for the reports of "paradoxical" distributions of fish larvae and their prey is to be found in the inefficiency and bias in the sampling methods used to evaluate the larval food resource. Failure to properly evaluate the larval food resource has led to inappropriate testing of some longstanding hypotheses in fisheries biology.

scholarly journals Food resource utilization of the skates Rioraja agassizii (Müller & Henle, 1841) and Psammobatis extenta (Garman, 1913) on the continental shelf off Ubatuba, South-eastern Brazil

2001 ◽  
Vol 61 (2) ◽  
pp. 217-238 ◽  
Author(s):  
E. Y. MUTO ◽  
L. S. H. SOARES ◽  
R. GOITEIN
Keyword(s):  
Feeding Habits ◽  
Food Resource ◽  
Stomach Content Analysis ◽  
Brazilian Coast ◽  
Relative Importance ◽  
Important Food ◽  
South Eastern ◽  
Eastern Brazil ◽  
Index Of Relative Importance ◽  
Food Resource Utilization

The feeding habits of Rioraja agassizii (syn. Raja agassizii) and Psammobatis extenta (syn. Psammobatis glansdissimilis) of the South-eastern Brazilian coast were studied by means of stomach content analysis. The samples were obtained on eight seasonal oceanographic cruises, carried out between October 1985 and July 1987. The importance of each food item was evaluated on the basis of the Index of Relative Importance and the feeding similarity by Percentage of Similarity. The results indicated that both species are benthic feeders, preying mainly on Crustacea, especially Amphipoda, Caridea and Brachyura. Teleostei were also important for R. agassizii. Seasonal variation of the diet seems to be associated with the availability of the prey, whose distribution and abundance are related to the dynamics of the water masses of the region. Juveniles and adults of P. extenta exploited the same resources while juveniles and adults of R. agassizii presented low diet similarity during most of the year. Caridea were an important food for all length classes of R. agassizii, while Amphipoda were for smaller specimens, and Teleostei for larger ones. The feeding overlap between the two species was higher during autumn 1986, winter 1986 and winter 1987.

The Influence of Temperature on the Activity of Sheep-Blowflies

1934 ◽  
Vol 25 (1) ◽  
pp. 85-99 ◽  
Author(s):  
A. J. Nicholson
Keyword(s):  
Constant Temperature ◽  
Quantitative Methods ◽  
Confined Space ◽  
General Activity ◽  
Temperature Preference ◽  
Closely Related Species ◽  
Thermal Death ◽  
Influence Of Temperature On ◽  
Bright Sunlight ◽  
Thermal Death Point

Summary1. Quantitative methods of recording the activity of blowflies are described.2. With constant temperatures the greatest activity occurs near the centre of the temperature range, whereas with rising temperature it immediately precedes the upper thermal death-point.3. Rising temperature causes activity to occur at a lower range of temperatures than does constant temperature.4. Rising temperature causes the appearance of “distress activity” at high temperatures, but constant temperature does not.5. For the development of the necessary energy for full crawling and flight activity at the most favourable temperatures, rather long exposure to these temperatures is necessary.6. Flight and, to a lesser extent, crawling occur in bursts of activity whether the temperature is rising or constant.7. Differences in the reactions to temperature of the closely related species Lucilia cuprina and L. sericata are very distinct.8. The curves for general activity and temperature preference correspond to the known distribution of the four species examined.9. Frequency of regurgitation is definitely associated with high temperature.10. There are strong indications that the conditions of the experiment were suitable for the flight of L. cuprina but unsuitable for that of the other species examined. This may have been due to the lack of bright sunlight, or to the confined space of the observation-jars.11. It is shown that activity is a complex phenomenon, and that the character of the results obtained is influenced by the kind of activity examined, by the methods of measurement used, and by the nature of the temperature conditions to which the insects are exposed.

Inter- and intra-guild patterns of food resource utilization by chironomid larvae in a subtropical coastal lagoon

Limnology ◽  
2013 ◽  
Vol 15 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Aurea Luiza Lemes-Silva ◽  
Paulo Roberto Pagliosa ◽  
Mauricio Mello Petrucio
Keyword(s):  
Resource Utilization ◽  
Coastal Lagoon ◽  
Food Resource ◽  
Chironomid Larvae ◽  
Food Resource Utilization

scholarly journals Consumer trait responses track change in resource supply along replicated thermal gradients

2021 ◽  
Vol 288 (1964) ◽  
Author(s):  
E. R. Moffett ◽  
D. C. Fryxell ◽  
F. Lee ◽  
E. P. Palkovacs ◽  
K. S. Simon
Keyword(s):  
Resource Availability ◽  
Nutrient Utilization ◽  
Thermal Gradients ◽  
Metabolic Demand ◽  
Reduced Body ◽  
Consumption Rates ◽  
Influence Of Temperature On ◽  
C And N ◽  
Increasing Temperature ◽  
Induced Changes

Rising temperatures may alter consumer diets through increased metabolic demand and altered resource availability. However, current theories assessing dietary shifts with warming do not account for a change in resource availability. It is unknown whether consumers will increase consumption rates or consume different resources to meet increased energy requirements and whether the dietary change will lead to associated variation in morphology and nutrient utilization. Here, we used populations of Gambusia affinis across parallel thermal gradients in New Zealand (NZ) and California (CA) to understand the influence of temperature on diets, morphology and stoichiometric phenotypes. Our results show that with increasing temperature in NZ, mosquitofish consumed more plant material, whereas in CA mosquitofish shifted towards increased consumption of invertebrate prey. In both regions, populations with plant-based diets had fuller guts, longer relative gut lengths, better-orientated mouths and reduced body elemental %C and N/P. Together, our results show multiple pathways by which consumers may alter their feeding patterns with rising temperatures, and they suggest that warming-induced changes to resource availability may be the principal determinant of which pathway is taken.

Sign in / Sign up

Export Citation Format

Share Document