The effect of medium on selected life-history traits in three clones of Lecane inermis (Rotifera) from activated sludge

2011 ◽  
Vol 63 (9) ◽  
pp. 2071-2076 ◽  
Author(s):  
Agnieszka Pajdak-Stós ◽  
Kocerba Wioleta ◽  
Edyta Fiałkowska ◽  
Beata Klimek ◽  
Janusz Fyda
Keyword(s):  
Life History ◽  
Chemical Composition ◽  
Mortality Rate ◽  
Activated Sludge ◽  
Mineral Water ◽  
Life History Traits ◽  
Culture Media ◽  
Control Agent ◽  
Egg Ratio ◽  
Lecane Inermis

We tested the effect of various culture media on life-history traits in three clones of the rotifer Lecane inermis, a potential bulking control agent. Four types of media were tested: a filtrate of activated sludge, mineral water, and each of these media enriched with molasses. The number of live and dead individuals and the number of amictic eggs were counted during the 14-day experiment, and the egg ratio (ER) and mortality rate were calculated. We found that the rotifers were well adapted to the changes in chemical composition of the medium and that the addition of molasses resulted in a significant increase in rotifer abundance. The highest ER was noted after two days, reaching a maximum of 4 eggs per female in treatments with filtrate and molassesenriched filtrate. The life-history traits varied depending on the clone and the medium, but all of the clones were able to survive and proliferate, even after 14 days of starvation.

Viral Life History Traits

2016 ◽  
Author(s):  
Joshua S. Weitz
Keyword(s):  
Life History ◽  
Mortality Rate ◽  
Host Cell ◽  
Life History Traits ◽  
Viral Infections ◽  
Burst Size ◽  
Host Cells ◽  
Viral Genomes ◽  
Life History Stages ◽  
Viral Progeny

This chapter discusses a number of key commonalities and differences among viral life history traits. Viruses have two key life history stages: inside and outside a host cell. Viral infections of microbes often lead to the death of host cells and the release of viral progeny. Viral infections can also lead to the integration of viral genomes with those of their hosts; induction of these genomes can result in subsequent lysis and release of viral progeny. Viruses are distinguished not only by the host they infect but also by the quantitative rates and levels at which these interactions take place. Viral life history traits reflect the combined interactions of viruses and hosts; that is, they are not encoded solely by viral genomes. Viral life history traits can also vary by orders of magnitude, whether for time to lysis, burst size, probability of lysogeny, rate of induction, adsorption rate, or mortality rate.

Life history traits of the exploited limpet Patella candei (Mollusca: Patellogastropoda) of the north-eastern Atlantic

2011 ◽  
Vol 92 (6) ◽  
pp. 1379-1387 ◽  
Author(s):  
P. Henriques ◽  
R. Sousa ◽  
A.R. Pinto ◽  
J. Delgado ◽  
G. Faria ◽  
...  
Keyword(s):  
Life History ◽  
Mortality Rate ◽  
Sexual Maturity ◽  
Life History Traits ◽  
Growth Parameters ◽  
Total Mortality ◽  
Recruitment Pattern ◽  
Length Relationship ◽  
North Eastern ◽  
Exploitation Rate

Life history traits of Patella candei were studied for the first time, including weight versus length relationship, growth, age structure, sexual maturity, recruitment pattern, mortality rates and yield and biomass-per-recruit of an exploited population in Madeira Island, north-eastern Atlantic using monthly length–frequency data from January to December 1999. The growth pattern of P. candei showed positive allometric nature of growth (b > 3, P < 0.05). The estimated growth parameters showed an asymptotic length (L∞) and growth coefficient (K) estimated at 80.81 mm and K at 0.32 year−1 with a growth performance index (φ′) calculated as 3.32 based on the collected data. This species is moderately long-lived reaching up to 9.36 years and achieving sexual maturity at 36.7 mm of shell length. The recruitment pattern was continuous, displaying a major peak event per year, occurring in January (25.12%). The estimated total mortality rate (Z) was 1.79 year−1 while natural mortality rate (M) was 0.55 year−1 and fishing mortality rate (F) was 1.24 year−1. The probability of capture shows that the length at first capture (Lc) was 42.7 mm, the exploitation rate (E) 0.693 and the maximum allowable limit of exploitation (Emax) was 0.779 for the highest yield. The exploitation rate was less than the predicted Emax values, showing that the stock of P. candei was found to be under-exploited in the investigated area; however, its slow growth and long life make it extremely vulnerable to over-exploitation.

scholarly journals Effect of petroleum-derived substances on life history traits of bird cherry-oat aphid (Rhopalosiphum padi L.) and on the growth and chemical composition of winter wheat

2018 ◽  
Vol 25 (27) ◽  
pp. 27000-27012 ◽  
Author(s):  
Milena Rusin ◽  
Janina Gospodarek ◽  
Aleksandra Nadgórska-Socha ◽  
Gabriela Barczyk ◽  
Elżbieta Boligłowa ◽  
...  
Keyword(s):  
Life History ◽  
Chemical Composition ◽  
Winter Wheat ◽  
Life History Traits ◽  
Rhopalosiphum Padi

Life History Traits of Hoplostethus Mediterraneus (Pisces: Beryciformes) From the North-Western Ionian Sea (Mediterranean Sea)

1998 ◽  
Vol 78 (1) ◽  
pp. 321-339 ◽  
Author(s):  
G. D'onghia ◽  
A. Tursi ◽  
C.A. Marano ◽  
M. Basanisi
Keyword(s):  
Life History ◽  
Mortality Rate ◽  
Life History Traits ◽  
Growth Parameters ◽  
Growth Patterns ◽  
Natural Mortality ◽  
Distribution Analysis ◽  
Ionian Sea ◽  
The North ◽  
North Western

The fish Hoplostethus mediterraneus is a bycatch of the deep-water trawling in the north-western Ionian Sea. Data on its life history traits were collected during twelve trawl surveys carried out at two month intervals, between August 1993 and July 1995.A vertical distribution according to size was observed for this species. The year's young were recruited mainly during the spring-summer period. Sex-ratio changed by size with females larger than males. Mature specimens were found mainly between May and November with a reproductive peak during late summer.Seasonal growth was detected in the otoliths; the maximum ages of 11 and 10 y were observed in females and males respectively. Von Bertalanffy growth parameters for the whole population were: L3C=287–08 mm, k=0–127 y, to=-2–131. No significant differences were detected between the growth patterns of the sexes. Overall growth perfomance depicted through size-distribution analysis was not significantly different from that obtained by otolith reading.Estimates of natural mortality rate for the whole population ranged from 0–14 to 0–20. Population structure, growth pattern, age at first maturity and low natural mortality rate indicate a life history mainly constituted by k-strategy characters and regulated by density-dependent mechanisms.

scholarly journals Life history parameters and predation capacities of Nesidiocoris volucer: a new biological control agent for tomato crop

2022 ◽  
pp. 1-9
Author(s):  
Lucie Marquereau ◽  
Jean-Sébastien Cottineau ◽  
Olivier Fontaine ◽  
Frédéric Chiroleu ◽  
Bernard Reynaud ◽  
...  
Keyword(s):  
Biological Control ◽  
Life History ◽  
Life History Traits ◽  
Biocontrol Agent ◽  
Insect Pests ◽  
Biological Control Agent ◽  
Control Agent ◽  
Tomato Crop ◽  
Tropical Areas ◽  
Plant Injury

Abstract Whiteflies are one of the major pests of tomato under greenhouses, and their control partly relies on biocontrol strategies. Among those biocontrol agents, parasitoids or predators are widely used. However, the introduction of a biocontrol agent in a new area is not trivial. For that reason, we investigated the use of a tropical native mirid, Nesidiocoris volucer (Hemiptera: Miridae), for the biological control of whiteflies among other insect pests on tomato crops under greenhouses in the subtropical island of La Réunion, France. Nesidiocoris volucer life history traits and plant injury were examined. Nymphs developed and survived between 15 and 30°C and required on average 49.41 days at 15°C and on average 10.50 days at 30°C to develop (nymph survival >94%). At 25°C, each female produced on average 65 eggs. Nesidiocoris volucer was able to feed on several prey species, but performed better on whiteflies than on spider mites or thrips. No N. volucer feeding injury was observed on tomato. Nesidiocoris volucer has also been found in tropical countries of Africa, and we believe that the data presented on this natural enemy could be of great importance for the biocontrol of whiteflies in tropical areas.

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