Carry-over effects of predation risk on postembryonic life-history stages in a freshwater shrimp

ROMINA BELÉN ITUARTE; MARÍA GUADALUPE VÁZQUEZ; MARÍA DE LOS ÁNGELES GONZALEZ SAGRARIO; EDUARDO DANIEL SPIVAK

ZOOLOGY

ELSEVIER GMBH

Año: 2014 vol. 117 p. 139 - 145

0944-2006

For organisms with complex life histories it is well-known that effects of risk experienced early in life, as embryo or larvae, can propagate through the life cycle. Although carryover effects have been well documented in invertebrates with different levels of parental care, there are few examples of predator-induced responses in externally brooded embryos. Here, we compared the effects of nonlethal fish predation risk through the embryonic development of newly spawned eggs carried by female shrimp on: timing of egg hatching, hatchling morphology, larval development and juvenile morphology for animals hatched from unexposed and risk-exposed eggs. We also determined maternal body mass at the end of the embryonic period. Exposure to predation risk cues during embryonic development led to larger larvae which also had longer rostra but reached the juvenile stage sooner, at a smaller size, and with shorter rostra. There was no difference in hatching timing, but changes in larval morphology and developmental timing showed that embryos perceived waterborne substances indicative of predation risk. In addition to carry-over effects on larval and juvenile stages, predation threat provoked a decrease of body mass in mothers exposed to predator cues while brooding. Our results suggest that risk-exposed embryos were able to recognize the same infochemicals as their mothers prior to manifesting a response in the free-living larval stage. Further studies assessing anti-predator phenotypes should include embryonic development, which seems to match morphology and developmental time of subsequent life-history stages, according to perceived environmental conditions.