Population regulation of a tropical damselfly in the larval stage by food limitation, cannibalism, intraguild predation and habitat drying

Oecologia ◽  
1994 ◽  
Vol 100-100 (1-2) ◽  
pp. 118-127 ◽  
Author(s):  
Ola M. Fincke
Keyword(s):  
Larval Stage ◽  
Intraguild Predation ◽  
Population Regulation ◽  
Food Limitation ◽  
Habitat Drying

scholarly journals The numerical response: rate of increase and food limitation in herbivores and predators

2002 ◽  
Vol 357 (1425) ◽  
pp. 1233-1248 ◽  
Author(s):  
Peter Bayliss ◽  
David Choquenot
Keyword(s):  
Food Availability ◽  
Population Regulation ◽  
Environmental Variability ◽  
Food Limitation ◽  
Numerical Response ◽  
Limiting Factors ◽  
Biological Interactions ◽  
Equilibrium Dynamics ◽  
Rate Of Increase ◽  
Non Equilibrium

Two types of numerical response function have evolved since Solomon first introduced the term to generalize features of Lotka–Volterra predator–prey models: (i) the demographic numerical response, which links change in consumer demographic rates to food availability; and (ii) the isocline numerical response, which links consumer abundance per se to food availability. These numerical responses are interchangeable because both recognize negative feedback loops between consumer and food abundance resulting in population regulation. We review how demographic and isocline numerical responses have been used to enhance our understanding of population regulation of kangaroos and possums, and argue that their utility may be increased by explicitly accounting for non–equilibrium dynamics (due to environmental variability and/or biological interactions) and the existence of multiple limiting factors. Interferential numerical response functions may help bridge three major historical dichotomies in population ecology (equilibrium versus non–equilibrium dynamics, extrinsic versus intrinsic regulation and demographic versus isocline numerical responses).

A field study of survival, growth, biomass and temperature dependence of Rana dalmatina and Rana temporaria larvae

1991 ◽  
Vol 12 (3) ◽  
pp. 229-243 ◽  
Author(s):  
Niels Riis
Keyword(s):  
Population Regulation ◽  
Rana Temporaria ◽  
Food Limitation ◽  
Developmental Time ◽  
Logarithmic Function ◽  
Gompertz Function ◽  
Interspecific Differences ◽  
Population Sizes ◽  
Present Distribution ◽  
Rana Dalmatina

AbstractThe ecology of eggs and tadpoles of the European brown frogs Rana dalmatina and Rana temporaria was investigated in six Danish ponds. Developmental time of eggs was a logarithmic function of temperature with the same exponents for both species. However the time constant was double in the early breeding R. dalmatina so hatching appears contemporarily at the actual temperatures. Tadpole growth was fitted better by the logistic than the Gompertz function. Transformation size diverged by a factor of 2 among populations intraspecifically; this is explained by food limitation. It is suggested that interspecific competition might have contributed to present distribution. Population sizes declined exponentially. Overall survival from eggs to froglets ranged from 1.8 to 6.7 % with the highest survival in the fast-growing R. temporaria. Interspecific differences in mortality rates remained inappreciable. Since mortality does not seem to be size-limited, factors influencing developmental time might affect populations appreciably. The importance of the tadpole phase in population regulation is stressed, especially in R. dalmatina, in which survival during the first 3 month nearly equalled survival during next 33 months from froglets to adults in females.

The early development of antenna and antennal sensilla in the noctuid moth, Agrotis segetum (Insecta: Lepidoptera)

1990 ◽  
Vol 48 (3) ◽  
pp. 502-503
Author(s):  
Eric Hallberg ◽  
Lina Hansén
Keyword(s):  
Cell Death ◽  
Stem Cell ◽  
Early Development ◽  
Larval Stage ◽  
Pupal Stage ◽  
Agrotis Segetum ◽  
Antennal Sensilla ◽  
Noctuid Moth ◽  
Standard Procedures

The antennal rudiments in lepidopterous insects are present as disks during the larval stage. The tubular double-walled antennal disk is present beneath the larval antenna, and its inner layer gives rise to the adult antenna during the pupal stage. The sensilla develop from a cluster of cells that are derived from one stem cell, which gives rise to both sensory and enveloping cells. During the morphogenesis of the sensillum these cells undergo major transformations, including cell death. In the moth Agrotis segetum the pupal stage lasts about 14 days (temperature, 25°C). The antennae, clearly seen from the exterior, were dissected and fixed according to standard procedures (3 % glutaraldehyde in 0.15 M cacaodylate buffer, followed by 1 % osmiumtetroxide in the same buffer). Pupae from day 1 to day 8, of both sexes were studied.

Effects of food limitation and emigration on self-thinning in experimental minnow cohorts

2000 ◽  
Vol 69 (6) ◽  
pp. 927-934 ◽  
Author(s):  
J. B. Dunham ◽  
B. R. Dickerson ◽  
E. Beever ◽  
R. D. Duncan ◽  
G. L. Vinyard
Keyword(s):  
Food Limitation

INTERACTIONS BETWEEN CYSTICERCUS FASCIOLARIS AND COMMON RATS

2017 ◽  
Vol 23 (2) ◽  
Author(s):  
SHASHI KIRAN
Keyword(s):  
Granulation Tissue ◽  
Larval Stage ◽  
Histopathological Examination ◽  
Sylvatic Cycle ◽  
Mature Larva ◽  
Hepatic Cysts ◽  
Cysticercus Fasciolaris ◽  
Taenia Taeniaeformis ◽  
Relationship Of ◽  
The Relationship

The objective of this study was to determine the relationship of C. fasciolaris with common rats. Cysticercus fasciolaris is the larval stage of Taenia taeniaeformis . Development of metacestodes ( Cysticercus fasciolaris) occur in the liver of rodents. An urban and a sylvatic cycle occurs. A total of 40 liver specimens of rats were examined. Histopathological examination revealed the presence of multiple hepatic cysts, and the C. fasciolaris larva was surrounded by granulation tissue. Large and separated ûbroblasts in different orientations with some neoplastic changes were seen in advanced hepatic cysticercosis. The bladder involved the larva and large chamber containing the small chamber and opalescent fluid. The scolex of the mature larva is distinctly large, bearing four lateral distinct suckers, a rostellum armed with double, and alternating rows of hooks.

Phoronida

2017 ◽  
Author(s):  
Judith Fuchs
Keyword(s):  
Life Cycle ◽  
Small Group ◽  
Larval Stage ◽  
Intertidal Zone ◽  
Marine Invertebrates ◽  
Tree Of Life ◽  
General Morphology ◽  
Family Level ◽  
Planktonic Larval Stage

This chapter describes the taxonomy of Phoronida, a small group of exclusively marine invertebrates found in most of the world's oceans from the intertidal zone to about 400 metres depth. Phoronids are meroplanktonic with a planktonic larval stage usually less than 2 mm in length and a benthic adult whose length ranges from a few cm up to 50 cm. The chapter covers their life cycle, ecology, and general morphology. It includes a section that indicates the systematic placement of the taxon described within the tree of life, and lists the key marine representative illustrated in the chapter (usually to genus or family level). This section also provides information on the taxonomic authorities responsible for the classification adopted, recent changes which might have occurred, and lists relevant taxonomic sources.

Selection and Population Regulation with Habitat Variation

1985 ◽  
Vol 126 (3) ◽  
pp. 418-429 ◽  
Author(s):  
Freddy Bugge Christiansen
Keyword(s):  
Population Regulation ◽  
Habitat Variation
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