Relative importance of parental diet versus larval nutrition on development and phenotypic plasticity of Pseudechinus huttoni larvae (Echinodermata: Echinoidea)

Abstract

The relative importance of parental and larval diets on development of larvae of the sea urchin Pseudechinus huttoni was examined. Laval parameters measured included the size of body components, development rate, morphological phenotypic plasticity, mortality rate, protein, lipid, carbohydrate and energy contents. We also investigated the influence of parental nutrition on fecundity, egg diameter and the eggs' protein, lipid and carbohydrate content. For a period of one year, adult P. huttoni were fed kelp (Macrocystis pyrifera) ad libitum every second day as a low-quality diet, or kelp ad libitum every day plus cockle (Austrovenus stutchburyi) flesh once a week as a high-quality diet. Adults fed the high-quality diet produced larger eggs and larvae with a slower development rate, longer arms relative to the midline length, and lower protein, lipid and carbohydrate contents. In larvae, higher concentrations of planktonic diet led to larger body components, a faster development rate and shorter arms relative to midline length. This study showed that parental nutrition has an important effect on development rate and morphological phenotypic plasticity in larvae of P. huttoni.

The Impact of Gene Expression Variation on the Robustness and Evolvability of a Developmental Gene Regulatory Network

“…Thus, it seems likely that a single maternal input, such as egg size or provisioning, independently influences variation in the expression of early genes and variation in larval morphology. The existence of such an input would explain why expression levels, as well as breeding values, are relatively highly correlated at time point 1 (Figures S2 and S3; Text S1) and is supported by experiments demonstrating that variation in egg size and quality influence the morphology of the larval skeleton [27],[47],[48]. Nonetheless, we cannot rule out the possibility that these genes act through the network via processes other than transcription or through interactions outside of this network such as changes in cell size.…”

“…These factors showed strong evidence of parental effects, particularly maternal effects (Table S4), as one might expect given the evidence for a relationship between variation in maternal egg quality and skeletal shape in echinoderms [47],[48]. For each gene at each time point, we then calculated Pearson's correlation coefficient between transcript abundance and each of these first three principal components.…”

“…After measuring the skeletons of larvae from each culture at time point 7 using established morphological landmarks [46],[47], we carried out a principle components analysis (PCA), and found that the first three principle components collectively explained ∼89% of overall variation in size and shape (Table S3). These factors showed strong evidence of parental effects, particularly maternal effects (Table S4), as one might expect given the evidence for a relationship between variation in maternal egg quality and skeletal shape in echinoderms [47],[48].…”

Effect of climate change on the reproduction pattern of sea urchin Echinometra mathaei at the Gulf of Suez, Red Sea, Egypt.

“…The environmental parameters have been suggested to play an important role in regulating the reproduction of E. mathaei. These parameters include temperature (Byrne 1990;Guillou and Michel 1993;King et al 1994;Vaı¨tilingon et al 2005;James et al 2007), photoperiod (Kelso 1971;McClintock andWatts 1990;Walker and Lesser 1998;Shpigel et al 2004), salinity (Harrington et al 2007), food availability (Lawrence and Lane 1982;Poorbagher et al 2010), population density (Bay-Schmith and Pearse, 1987), wave swept area (Muthiga and Jaccarini, 2005) and pH (Pearse and Cameron 1991), from these parameters temperature have the major role in governing E. mathaei reproduction. This was recorded from the current study as well as from other studies (Byrne, 1990;Siikavuopio et al, 2006Siikavuopio et al, , 2008 Gonadal indices and their changes over time have been used as indicators of reproductive cycle for many species of marine animals.…”

Phenotypic Plasticity of Feeding Structures in Marine Invertebrate Larvae

“…Alternatively, conditions of sperm limitation might have selected for large eggs to increase fertilization success (Levitan, 1993;Podolsky and Strathmann, 1996), indirectly affecting larval traits. Several studies indicate that arm-length plasticity is primarily expressed (or at least is detectable) during early larval development (Boidron-Metairon, 1988;Hart and Scheiblin g, 1988;Eckert, 1995;Miner, 2007;Adams et al, 2011; though see Hart and Strathmann, 1994;George, 1999) and that the capacity for plasticity of arm length early in development is associated with the amount of maternally provisioned energetic reserves, and thus with egg size (Bertram and Strathmann, 1998;McAlister, 2007b;Reitzel and Heyland, 2007;Bertram et al, 2009;Poorbagher et al, 2010a;2010b). These results suggest that larvae utilize endogenous resources for the initial production of food-collecting structures, and then exploit exogenous resources for the development of other, later-appearing structures.…”