Search results for "Fecundity"
showing 4 items of 104 documents
Effects of salinity, temperature and food level on the demographic characteristics of the seawater rotifer Synchaeta littoralis Rousselet.
2001
A strain of the seawater species Synchaeta littoralis, isolated from a Spanish Mediterranean coastal salt marsh, was cultured in the laboratory and fed with the alga Tetraselmis sp. The effect of three salinities (25 per thousand, 30 per thousand and 35 per thousand), two temperatures (20 degrees C and 25 degrees C) and two food levels (75,000 and 150,000 cells ml(-1)) on demographic parameters was studied using a life table approach. Average lifespan (LS) ranged between 4.0 and 7.3 days, net reproductive rate (R(0)) between 4.2 and 9.1 offspring per female, and intrinsic growth rate (r) between 0.50 and 0.95 day(-1). Salinity and temperature had a significant negative effect (***p<0.001) o…
Pyriproxyfen, a juvenoid hormone analog, does not induce male production in parthenogenetic lineages of Eucypris virens (Crustacea: Ostracoda)
2007
Analogs of juvenoid hormones are increasingly recommended for controlling insect pests in agriculture. One of these analogs, pyriproxyfen, was found to be very potent in inducing male production in Daphnia under laboratory conditions, even after acute exposure. Other studies also demonstrated a major role of juvenoid hormones for the sex determination in arthropods that have sex chromosomes. We exposed parthenogenetic lineages of the freshwater ostracod Eucypris virens to a wide range of pyriproxyfen concentrations, and compared mortality and fecundity between treated and control animals. Animals exposed to the highest concentrations of pyriproxyfen (3-30 nM) experienced a higher mortality …
Intestinal distribution and fecundity of two species ofDiplostomumparasites in definitive hosts
2005
This paper investigated the intestinal distribution and fecundity of 2 species ofDiplostomumparasites,D. spathaceumandD. pseudospathaceum, in 2 species of definitive hosts, herring gull (Larus argentatus) and common gull (L. canus), using both empirical field data and experimental infections. At the level of individual hosts, the parasite species occupied different parts within the intestine, but the fecundity of the worms, measured as the number of eggs in the uterus, did not differ between the parasite species except in wild common gulls. Interestingly, egg numbers in individual hosts were positively correlated between the parasite species suggesting that some birds provided better resour…
Data from: Age-related effects of chronic hantavirus infection on female host fecundity
2016
1. Pathogens often cause detrimental effects to their hosts and, consequently, may influence host population dynamics that may, in turn, feed back to pathogen transmission dynamics. Understanding fitness effects of pathogens upon animal host populations can help to predict the risks that zoonotic pathogens pose to humans. 2. Here we determine whether chronic infection by Puumala hantavirus (PUUV) affects important fitness-related traits, namely the probability of breeding, reproductive effort and mother and offspring condition, in the bank vole (Myodes glareolus). Using 9 years empirical data in a PUUV endemic area in Central Finland, we found differences between reproductive characteristic…