Persistent maternal identity effects on life history traits in Daphnia

Abstract

The aim of the present study was to examine the magnitude and persistence of maternal effects in Daphnia, in particular maternal identity effects. I studied life history traits of a single clone of Daphnia galeata born to 40 different mothers belonging to three age groups. Maternal identity had large effects on offspring traits, that is, identically treated clonal females differed substantially in respect to the traits of their offspring, including size at birth, age at maturity, and number of second generation offspring. The effects of maternal identity on these traits were largely independent of maternally induced differences in offspring size, indicating that maternal effects were mediated through offspring quality. Maternal age also affected offspring traits: older mothers gave birth to larger offspring which matured earlier, were larger and more fecund, and survived better until maturity. Individuals which were larger at birth also had a better chance of survival. Contrary to expectation, I found little evidence that maternal identity or maternal age had any influence on their offsprings' response to fish kairomones.

How do interactive maternal traits and environmental factors determine offspring size inDaphnia magna?

“…Other studies have shown similar relationships where the effort per offspring (in terms of size or mass of eggs or neonates) increased with maternal body size for different clones of D. magna, under high and low food conditions (Glazier, 1992;Ebert, 1993;McKee and Ebert, 1996). Positive effects of maternal body size on OS were observed in other Daphnia species such as D. galeata (Sakwinska, 2004) or D. hyalina (Burns, 1995) and in other organisms (Bernardo, 1996) as well.…”

“…Our results support the findings of Ebert (1993), showing that age and brood number did not affect OS in two D. magna populations from different artificial ponds, but the food level, maternal body size and brood size strongly affected OS. However, opposite results were observed for D. galeata (Sakwinska, 2004) where the juvenile growth increment differed between young, intermediate and older mothers, leading to a dependence of OS on maternal age. The observed variability in the factors determining OS in Daphnia could be attributed to interspecies differences.…”

“…However, an important limitation of these available models is that none of them accounts for the natural variability in the offspring size (OS) in Daphnia magna. This trait, in fact, determines vital individual processes such as growth (Hammers-Wirtz and Ratte, 2000), size at first reproduction (Barata and Baird, 1998) or size-selective predation (Lampert, 1993;Gergs and Ratte, 2009), which in turn affect higher-order processes such as population growth rate, maturation (Sakwinska, 2004;Rinke, 2006), population survival rates (Sakwinska, 2004;Dudycha and Lynch, 2005) or resistance to starvation (Tessier and Consolatti, 1991).…”

Life history consequences of sterol availability in the aquatic keystone species Daphnia

“…Although size at birth is an important fitness determinant (Tessier and Consolatti 1989;Lampert 1993), maternal effects on subsequent life stages should be considered when offspring performance and population dynamics are analyzed since offspring quality is not necessarily reflected in size at birth (Sakwinska 2004). Therefore, we reared first-clutch neonates of experimental mothers grown with the various food regimes on a 100% Syn diet.…”

Ecological genomics in Daphnia: stress responses and environmental sex determination

“…The quality of the maternal environment influences traits such as size at birth and number of offspring (Sakwinska, 2004), strain-specific immunity to bacterial parasites (Little et al, 2003) and energy allocation to offspring (LaMontagne and McCauley, 2001). Interestingly, mothers reproducing in poor environments produced offspring more than twice as resistant to bacterial infection as mothers in favorable environments (Mitchell and Read, 2005).…”