scholarly journals Growth and Reproduction of Planorbarius corneus (Linnaeus, 1758) in Laboratory Conditions

2021 ◽  
Vol 79 (3) ◽  
pp. 111-118
Author(s):  
Neda Mažuran ◽  
Goran Kovačević
Keyword(s):  
Reproductive Output ◽  
Toxicity Testing ◽  
Significant Negative Correlation ◽  
Age At First Reproduction ◽  
Planorbarius Corneus ◽  
Laboratory Conditions ◽  
Hatching Time ◽  
Test Organisms ◽  
Quantitative Results ◽  
Growth And Reproduction

Abstract This study presents the results of observation on growth and reproduction of Planorbarius corneus (Linnaeus, 1758) (Gastropoda, Pulmonata) over the course of several years of continuous rearing in the laboratory in order to use them as test organisms for toxicity testing of chemicals. Some growth and reproduction features (shell diameter increase, fecundity, hatching time and rate, age at first reproduction, juvenile survival), which could provide more information for culturing P. corneus in the laboratory, are presented. The quantitative results of growth and reproduction in laboratory conditions were obtained: heterogenous growth varied between 0.1 mm and 5.3 mm in individual snails, production of 0.6 egg masses per snail/day and 11 eggs per snail/day. A statistically significant negative correlation between initial snail size and growth was noticed. In the second part of the experiment, the reproductive output of 4 isolated snails was compared to that of permanently grouped snails. As a result, 2-fold decreased growth and 4-fold decreased reproductive output in the progeny of isolated animals was noticed.

Marine Biosurfactants, III. Toxicity Testing with Marine Microorganisms and Comparison with Synthetic Surfactants

1991 ◽  
Vol 46 (3-4) ◽  
pp. 210-216 ◽  
Author(s):  
Knut Poremba ◽  
Wilfried Gunkel ◽  
Siegmund Lang ◽  
Fritz Wagner
Keyword(s):  
Marine Bacterium ◽  
Sea Water ◽  
Toxicity Testing ◽  
Test System ◽  
Marine Microorganisms ◽  
Oil Dispersants ◽  
Test Organisms ◽  
Pure Cultures ◽  
Microtox Test ◽  
Synthetic Surfactants

Eight synthetic and nine biogenetic surfactants were tested on their toxicity. Because of their possible application as oil dispersants against oil slicks on sea. the test organisms used were marine microorganisms (mixed and pure cultures of bacteria, microalgae, and protozoa). Bacterial growth was hardly effected or stimulated, whilst that of algae and flagellates was reduced. All substances tested were biodegradaded in sea water. The bioluminescence of Photobacter phosphoreum (Microtox test) was the most sensitive test system used. A ranking shows that most biogenetic surfactants were less toxic than synthetic surfactants. No toxicity could be detected with the glucose-lipid GL. produced by the marine bacterium Alcaligenes sp. MM 1.

Single- and multi-species toxicity testing with nematodes.

2021 ◽  
pp. 298-322
Author(s):  
Sebastian Höss
Keyword(s):  
Caenorhabditis Elegans ◽  
Test Organism ◽  
Toxicity Testing ◽  
Single Species ◽  
Risk Assessments ◽  
Freshwater Sediments ◽  
Nematode Communities ◽  
Model Ecosystems ◽  
Test Organisms ◽  
Experimental Approaches

Abstract This chapter discusses the utility of nematodes in experimental ecotoxicology, and specifically in the study of freshwaters. Drawing on reports in which nematodes were used as test organisms in single-species tests as well as studies investigating nematode communities in model ecosystems (i.e. microcosms), the suitability of nematode-based experimental approaches in prospective and retrospective risk assessments of chemicals in freshwater sediments is examined. Several examples are presented of the use of Caenorhabditis elegans as a test organism in single-species bioassays, in order to demonstrate the versatility of this nematode for ecotoxicological investigations.

Effects of simulated herbivory on growth and reproduction of two beach annuals, Cakile edentula and Corispermum hyssopifolium

1992 ◽  
Vol 70 (12) ◽  
pp. 2467-2475 ◽  
Author(s):  
Kevin E. Gedge ◽  
M. A. Maun
Keyword(s):  
Reproductive Output ◽  
Natural Habitat ◽  
Critical Time ◽  
Insect Herbivores ◽  
Compensatory Response ◽  
Large Numbers ◽  
Cakile Edentula ◽  
Specialist Insect ◽  
Heavy Damage ◽  
Growth And Reproduction

Cakile edentula var. lucustris (sea rocket) and Corispermum hyssopifolium (bugseed) are two annual flowering plants that grow on the sandy shores of the Great Lakes. This habitat is extremely unpredictable and plants are subject to grazing by a number of insect herbivores as well as browsing by white-tailed deer. The objectives of these studies were to estimate the extent of herbivore damage under natural conditions, to determine the most vulnerable stage of damage, and to examine the compensatory ability of each species to tolerate herbivory. Greenhouse experiments showed that both species were able to compensate for low to moderate levels of artificial defoliation. However, high levels near the time of anthesis reduced the growth and reproductive output of both species. Similar experiments in the field revealed that although the critical time of damage was still the same, the plants were less able to tolerate herbivory. Cakile edentula plants exposed to natural herbivory in an unsprayed cabbage field were quickly attacked by large numbers of specialist insect herbivores and completely defoliated in 11 days. The fact that such damage does not occur in its natural habitat suggests that Cakile edentula escapes heavy damage because insects are unable to locate these populations along the shoreline. Key words: white-tailed deer, defoliation intensity, defoliation stage, compensatory response, indeterminate growth.

scholarly journals Algal growth at environmentally relevant concentrations of suspended solids: implications for microplastic hazard assessment

2020 ◽  
Author(s):  
Elena Gorokhova ◽  
Karin Ek ◽  
Sophia Reichelt
Keyword(s):  
Particle Size ◽  
Adverse Effects ◽  
Growth Inhibition ◽  
Hazard Assessment ◽  
Suspended Solids ◽  
Algal Growth ◽  
Toxicity Testing ◽  
Distribution Data ◽  
Test Organisms ◽  
High Concentrations

AbstractHazard assessment of microplastic is challenging because standard toxicity testing is mostly developed for soluble (at least partially) chemicals. Adverse effects can occur when test organisms are exposed to turbid environments with various particulate matter (PM), both natural, such as sediment, and anthropogenic, such as microplastic. It is, therefore, relevant to compare responses to PM exposure between the microplastic and other suspended solids present at ecologically relevant concentrations; this can be done by using reference materials when assessing hazard potential of microplastics. Here, we evaluated growth inhibition in unicellular alga Raphidocelis subcapitata exposed to different suspended solids (microplastic, kaolin, and cellulose; 10, 100 and 1000 mg/L) during 72 h; algae without added solids were used as a control. In addition, aggregate formation in the exposure systems was analyzed using particle size distribution data. At 10 and 100 mg/L, no adverse growth effects were observed in any treatments; moreover, algal growth was significantly stimulated in kaolin and cellulose treatments compared to the control. However, at 1000 mg/L, all tested materials exerted growth inhibition, with no significant differences among the treatments. The comparison among particle size distributions across the treatments showed that both PM concentration and size of the particle aggregates were significant growth predictors for all materials tested. Therefore, at high concentrations, both natural and anthropogenic materials have similar capacity to cause adverse effects in algal growth inhibition tests, which must be taken into account in hazard assessment of plastic litter.

scholarly journals Heterothermy is associated with reduced fitness in wild rabbits

2017 ◽  
Vol 13 (12) ◽  
pp. 20170521 ◽  
Author(s):  
Shane K. Maloney ◽  
Maija K. Marsh ◽  
Steven R. McLeod ◽  
Andrea Fuller
Keyword(s):  
Body Temperature ◽  
Oryctolagus Cuniculus ◽  
Reproductive Output ◽  
Core Body Temperature ◽  
The Body ◽  
The Core ◽  
Temperature Rhythm ◽  
Body Temperature Rhythm ◽  
Core Body ◽  
Growth And Reproduction

An increase in variation in the 24 h pattern of body temperature (heterothermy) in mammals can be induced by energy and water deficits. Since performance traits such as growth and reproduction also are impacted by energy and water balance, we investigated whether the characteristics of the body temperature rhythm provide an indication of the reproductive success of an individual. We show that the amplitude of the daily rhythm of body temperature in wild rabbits ( Oryctolagus cuniculus ) prior to breeding is inversely related to the number of pregnancies in the subsequent seven months, while the minimum daily body temperature is positively correlated to the number of pregnancies. Because reproductive output could be predicted from characteristics of the core body temperature rhythm prior to the breeding season, we propose that the pattern of the 24 h body temperature rhythm could provide an index of animal fitness in a given environment.

Variation in growth and reproduction of Bolomys lasiurus (Rodentia: Muridae) in an Amazonian savanna

1995 ◽  
Vol 11 (3) ◽  
pp. 419-428 ◽  
Author(s):  
Angelo De Lima Francisco ◽  
William E. Magnusson ◽  
Tânia M. Sanaiotti
Keyword(s):  
Direct Effect ◽  
Growth Rates ◽  
Reproductive Output ◽  
Dry Season ◽  
Consistent Pattern ◽  
Wet Season ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Lactating Females ◽  
Growth And Reproduction

ABSTRACTReproduction by Bolomys lasiurus is strongly seasonal in the Amazonian savanna of Alter do Chāo, Pará, Brazil. No pregnant or lactating females were recorded during the early dry season (July-September). Relative growth rates showed a similar though less consistent pattern. These patterns do not appear to be due to a direct effect of rainfall as high reproduction and growth were recorded during the late dry season (October-November), even though rainfall and the availability of fruits of shrubs were low during that period. It is likely that reinitiation of reproduction during the dry season is due to an increase in the availability of invertebrates and/ or wind-dispersed seeds. Fire at the end of the dry season appears to affect the diet of the rats, causing an increase in the ingestion of invertebrates during the following wet season. However, our data do not indicate that fire affects individual reproductive output or growth.

Survival of the root-lesion nematode Pratylenchus jordanensis Hashim in a fallow field after harvest of alfalfa

Nematology ◽  
1999 ◽  
Vol 1 (1) ◽  
pp. 79-84 ◽  
Author(s):  
Annamalai Mani
Keyword(s):  
Storage Temperature ◽  
Soil Layer ◽  
Significant Negative Correlation ◽  
Soil Layers ◽  
Laboratory Conditions ◽  
Top Soil ◽  
De Se ◽  
Fallow Field ◽  
Lesion Nematode ◽  
And Storage

AbstractSurvival of Pratylenchus jordanensis Hashim was studied in a field in fallow after the harvest of a crop of alfalfa and in storage under laboratory conditions. The nematodes survived in dry roots/ root residues under field conditions for 100 days. Vertical migration of the nematodes to deeper soil layers was observed when the top soil layer dried up. High numbers of nematodes survived at both 0-15 and 16-30 cm depths for 100 days. Then the field was ploughed under, which caused the soil to dry and the populations to decline. The nematodes survived for 380 days in a fallow field. They survived for 270 and 272 days under laboratory conditions in wet and shade-dried soil, respectively, and for 124 days in natural field soil at 30 degrees C. Significant negative correlation between nematode populations and storage temperature and positive correlation between nematode populations and soil moisture were observed. P. jordanensis did not survive for long in a drop of water on a glass slide, whereas it survived in filter paper discs for varying periods at different relative humidity levels. Survie de Pratylenchus jordanensis Hashim dans les jacheres suivant la recolte de luzerne - La survie de Pratylenchus jordanensis Hashim dans les jacheres suivant la recolte de luzerne et dans du sol stocke au laboratoire a ete etudiee. Au champ, le nematode survit 100 jours dans les racines dessechees ou les fragments de celles-ci. Il a ete observe une migration verticale des nematodes vers les couches plus profondes du sol lorsque la surface de celui-ci se desseche. Un grand nombre de nematodes survivent 100 jours a des profondeurs de 0-15 et 16-30 cm apres quoi les populations declinent du fait de la dessiccation causee par le labourage du champ. A 30 degrees C, le nematode survit 270 jours dans du sol humide, 272 jours dans du sol seche a l'ombre - l'un et l'autre dans les conditions du laboratoire - et 124 jours dans le sol naturel au champ. Il a ete observe des correlations significatives, negatives, entre populations du nematode et temperature de stockage, et positives, entre populations du nematode et humidite du sol. P. jordanensis ne survit pars longtemps dans une goutte d'eau placee sur une lame porte-objet, tandis qu'il est capable de se maintenir pendant des periodes plus ou moins longues si place sur des disques de papier filtre soumis a des taux d'humidite relative varies.

Growth and body size in Blanding's turtles (Emydoidea blandingi): relationships to reproduction

1991 ◽  
Vol 69 (1) ◽  
pp. 239-245 ◽  
Author(s):  
Justin D. Congdon ◽  
Richard C. van Loben Sels
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Egg Size ◽  
Reproductive Output ◽  
Body Sizes ◽  
Minimum Age ◽  
Average Size ◽  
Average Body ◽  
Clutch Mass ◽  
Growth And Reproduction

Growth and reproduction in Blanding's turtles (Emydoidea blandingi) were studied in southeastern Michigan from 1975 through 1988. Average body sizes of both sexes of adults were similar; however, shapes of males were different from those of females. The average size of a group of females with a mean minimum age of 47 years was not significantly different from a younger group with a mean age of 21 years. Clutch size ranged from 3 to 19 ([Formula: see text], N = 280) eggs over 11 years. Clutch wet mass ranged from 60.4 to 183.4 g ([Formula: see text], N = 17), and relative clutch mass of nine females averaged 0.12. Clutch size, and to a lesser degree egg size, showed a significant positive relationship with body size, but not with age of females. Hatchlings averaged 31.0 mm in plastron length, 35.3 mm in carapace length, and 9.2 g in body wet mass. Differences in juvenile growth rates and age at sexual maturity appear to be the major cause of variation in body size of adult Blanding's turtles and the related reproductive output per clutch.

scholarly journals Nodulation and Nitrogen Fixation of Pongamia pinnata

2017 ◽  
Vol 4 (1) ◽  
pp. 1-12
Author(s):  
Phoebe N. Calica
Keyword(s):  
Nitrogen Fixation ◽  
Symbiotic Nitrogen Fixation ◽  
Current Knowledge ◽  
Fixed Nitrogen ◽  
Qualitative And Quantitative ◽  
Naturally Occurring ◽  
Reduction Assay ◽  
Quantitative Results ◽  
Preliminary Study ◽  
Growth And Reproduction

Nitrogen is one of the most important nutrients required by plants as a major component of all nucleic acids and proteins such as enzymes which control and enable their growth and reproduction. While much research has been conducted on the legume tree Pongamia (a candidate source for renewable biofuel), there is only a handful of studies on the mechanisms and regulation of nitrogen fixation, which is considered as one of the most important domestication traits that needs to be investigated.  Steps to optimize the symbiotic nitrogen fixation of Pongamia is, firstly, to select the best rhizobial isolates as inoculum among the naturally-occurring pool of bacteria in soils across Queensland. There have been reports on rhizobia nodulating Pongamia isolated from Western Australia and India but not in Queensland, Australia. This study is the first to report such rhizobia isolates that nodulated Pongamia.  Secondly, is to establish efficient nodulation by studying the factors such as nitrate and salinity. The published literature has provided extensive details on the effects of these factors in nodulation and their mechanisms in various legumes. However, only one preliminary study was published from our laboratory; the present study is the in-depth continuation of that effort. Lastly, nitrogen fixation in Pongamia must be assessed to determine if fixed nitrogen is sufficient to support its growth and reproduction. Acetylene reduction assay is the simplest and most common method of assessing fixed nitrogen but in this research, different methods were explored in order to compare both qualitative and quantitative results. This review summarises the current knowledge related to Pongamia, rhizobia, nodulation and nitrogen fixation.

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