Latent Effects: Surprising Consequences of Embryonic and Larval Experience on Life after Metamorphosis

Abstract

The coming years will apparently bring increases in seawater temperatures, salinity fluctuation, and ocean acidity, along with increasing pollution levels and increasing incidences of coastal hypoxic events. We can also expect to see shifting patterns of phytoplankton abundance and nutritional quality. Many such stresses experienced early in development—even among brooded embryos—have been found to influence growth rates, survival, and other fitness characteristics following metamorphosis, sometimes for months, both in laboratory studies and in those in which juveniles were transplanted to the field. The effects are usually negative, but have been seemingly positive in a few studies. Vulnerability can vary among species, and even among the offspring from different parents. The mechanisms through which such “latent effects” are mediated are unclear: energy-balance issues and epigenetic factors—in which gene expression patterns are altered without any changes in DNA sequences—seem to be involved.

Epigenetic‐associated phenotypic plasticity of the ocean acidification‐acclimated edible oyster in the mariculture environment

“…This plasticity would help larvae adapt rapidly to a specific environment before altering genetics (Longa, 2019). Larvae exposed to OA were more capable of optimally regulating internal water balance and osmotic homeostasis to allow cells to proliferate and differentiate, in which DNA methylation may potentially be involved (Covelo-Soto et al, 2015;Pechenik, 2017).…”

“…Several previous laboratory studies have shown that OA as a single stressor or OA combined with other environmental stressors can reduce (Bryne et al, 2019;Byrne & Przeslawski, 2013;Espinel-Velasco et al, 2020;Ko et al, 2014;Ross et al, 2016) or improve (Bryne et al, 2019;Lim et al, 2020;Ross et al, 2016) growth, metabolism, calcification and survival of several economically important and edible mollusc species, especially oysters. While these studies have focused on a single life stage, the consequences of OA can result from carry-over effects, in which prior experience of stress exposure in one life stage can be passed onto the next life stage (Pechenik, 2006(Pechenik, , 2017. For example, the low pH (7.7-7.8) experienced during the larval stage did not affect the growth and shell structure of the Pacific oyster, Crassostrea gigas, in the Yellow Sea (Ko et al, 2013) but deteriorated the growth of the estuarine Olympia oyster, Ostrea lurida (Hettinger et al, 2012), Sydney Rock oyster, Saccostrea glomerata, and C. gigas from New South Wales (Parker et al, 2009) during their juvenile stages.…”

Having cake and eating too: The benefits of an intermediate larval form in a brittle star Amphiodia sp. opaque (Ophiuroidea)

“…Metamorphosis does not promise a new beginning: embryonic and larval experiences can be expressed latently in juvenile and adult quality (Emlet & Sadro, 2006 ; Pechenik, 2006 ). Food limitation and prolonged planktonic duration have been shown to negatively influence juvenile size, growth, and survival (reviewed in Pechenik, 2018 ). In facultative planktotrophs, larval feeding resulted in larger juveniles in echinoderms (Allen & Podolsky, 2007 ; Emlet, 1986 ; Hart, 1996 ) and gastropods (Kempf & Hadfield, 1985 ; Miller, 1993 ).…”

“…Metamorphosis does not promise a new beginning: embryonic and larval experiences can be expressed latently in juvenile and adult quality (Emlet & Sadro, 2006;Pechenik, 2006). Food limitation and prolonged planktonic duration have been shown to negatively influence juvenile size, growth, and survival (reviewed in Pechenik, 2018).…”