Effects of food quality on growth and body composition of the collembolan Orchesella cincta

Abstract

Abstract. The effects of food quality on growth and body composition of the collembolan Orchesella cincta (L.) (Entomobryidae) were investigated to determine optimal values for dietary nitrogen.Hyphae of Cladosporium cladosporioides containing 2.2%, 2.7%, 4.0% and 6.2% nitrogen were used as food sources.These different nitrogen contents were obtained by adjusting the medium on which the fungi were grown.Collembola were fed on one of these four food sources for 8 weeks. O.cincta grew faster and reached a higher asymptotic body mass when fed on fungi with 4% or 6.2% nitrogen content: this effect decreased with higher nitrogen content.The lipid concentration in the animals was negatively correlated with dietary nitrogen content, whereas protein concentration was positively correlated.Glycogen concentration was not found to correlate with the composition of the food. A mechanism is proposed by which O.cincta compensates for low dietary nitrogen by consuming more to maintain a relatively constant amount of protein in its body and, as a result, accumulates more fat than animals fed on fungi with a higher nitrogen content.

Age-dependent shift in response to food element composition in Collembola: contrasting effects of dietary nitrogen

“…In contrast, adult feeding rate is apparently unaVected by algal type, suggesting that the low food quality of [¡N] algae does not involve any directly harmful or deterrent eVects. Also, our results did not reveal any sign of compensatory feeding to increase overall N intake and thus protein synthesis, which has been suggested for two other collembolan species (Lavy and Verhoef 1996a;Haubert et al 2004).…”

“…Ammonium excretion is the most important pathway for N-excretion in Collembola (Sjursen and Holmstrup 2004), and if excretion does not keep up with the ammonium released by metabolism, internal accumulation of ammonium reaches toxic levels even if the relative N content of the algae was lower than in the animals. Also, negative eVects of increased N content in fungi have been demonstrated in a few collembolan species, but causation has not been addressed (Booth and Anderson 1979;Lavy and Verhoef 1996a (Birkemoe and Liengen 2000). The N-Wxing cyanobacteria (dominated by Nostoc commune) may attain C:N ratios of around six (Roger et al 1986), a much higher N content than even that of the [F] algae.…”

“…However, it has also been shown that high food N-content may have inhibitory eVects on some species (Booth and Anderson 1979;Lavy and Verhoef 1996a). While there has been much work focusing on the role of P in aquatic microinvertebrates (Sterner and Elser 2002), there are less data on how terrestrial invertebrates depend on dietary P, and no information exists on the response of Collembola to high dietary levels of P.…”

Effects of woodland restoration and management on the community of surface-active arthropods in the metropolitan Chicago region

“…The above pattern can be explained by a shift in epigeic arthropod community structure defined by taxa that is driven primarily by changes in the two most-frequently captured groups: springtails of the family Entomobryidae, which are primarily fungal grazers (Vegter, 1983;Lavy and Verhoef, 1996); and non-native isopod crustaceans (Jass and Klausmeier, 2000;Maerz et al, 2005), which largely consume detritus directly (Hassall et al, 1987;Lavy et al, 2001;Zimmer et al, 2002). Entomobryids were more prevalent in the Managed-REF sites, which represent land managers' restoration goals of pre-disturbance conditions, whereas introduced isopods occurred in higher proportions in the degraded Control sites.…”

Reproductive Impairment in the Zebrafish, Danio rerio, upon Chronic Exposure to 1,2,3-Trichlorobenzene

“…Glycogen determination was done according to the method of Roe and Daily (1966) with minor modi"cations. It is known that some tissue components may interfere with the glycogen measurements (Roe and Daily, 1966;Lavy and Verhoef, 1996). To preclude this interference, the homogenates were "rst centrifuged at 10,000 g for 10 min at 43C.…”