Trade-offs between timing of metamorphosis and grow-out performance of a marine caridean shrimp juveniles and its relevance for aquaculture

Abstract

Information on the aquaculture performance of marine caridean shrimp is still scarce when compared with that of freshwater species (e.g. Macrobrachium spp.) or penaeids. Moreover, most studies addressing shrimp aquaculture focus either larval performance or juvenile grow-out, with the vast majority overlooking the potential existence of carry-over effects from one life stage to the next. Such effects in phenotypic traits may be expressed when species undergo dramatic shifts, such as at metamorphosis. The present study evaluated the existence of potential trade-offs between the timing of metamorphosis and the grow-out performance displayed by juvenile marine caridean shrimp using Lysmata seticaudata, a marine ornamental species, as model. Larvae that delayed metamorphosis for longer periods (termed as late settlers – LS) gave origin to significantly larger sized post-larvae (7.37 ± 0.25 mm total length), than that displayed by early or middle settlers (ES and MS, 6.95 ± 0.28 mm and 7.02 ± 0.24 mm, respectively). However, at the end of the grow-out period juvenile shrimp originating from LS postlarvae displayed a significantly smaller TL (10.38 ± 0.82 mm) than that displayed from conspecifics originating from ES and MS (11.20 ± 1.02 and 11.22 ± 0.62 mm, respectively). The larger size attained by L. seticaudata post-larvae originating from specimens that delayed metamorphosis (LS) is likely achieved by trading-off endogenous energetic reserves that, once allocated to delay the transition to benthic life will no longer be available to help fueling early juvenile growth. The present work suggests that a detailed record on the timing of metamorphosis can be a more reliable proxy to access the grow-out performance of juvenile marine caridean shrimp than postlarval size at metamorphosis. An optimal aquaculture of organisms with complex life-cycles, such as decapod crustaceans, relies on the detailed knowledge of each life stage performance, as the exposure to suboptimal conditions during early life stages may give origin to phenotypic traits that are carried-over and only displayed later in the life cycle (e.g. post-metamorphosis).