Long lasting effects of early temperature exposure on the swimming performance and skeleton development of metamorphosing Gilthead seabream (Sparus aurata L.) larvae

Temperatures experienced during early ontogeny significantly influence fish phenotypes, with clear consequences for the wild and reared stocks. We examined the effect of temperature (17, 20, or 23 degrees C) during the short embryonic and yolk-sac larval period, on the swimming performance and skeleton of metamorphosing Gilthead seabream larvae. In the following ontogenetic period, all fish were subjected to common temperature (20 degrees C). The critical swimming speed of metamorphosing larvae was significantly decreased from 9.7 +/- 0.6 TL/s (total length per second) at 17 degrees C developmental temperature (DT) to 8.7 +/- 0.6 and 8.8 +/- 0.7 TL/s at 20 and 23 degrees C DT respectively (p < 0.05). Swimming performance was significantly correlated with fish body shape (p < 0.05). Compared with the rest groups, fish of 17 degrees C DT presented a slender body shape, longer caudal peduncle, terminal mouth and ventrally transposed pectoral fins. Moreover, DT significantly affected the relative depth of heart ventricle (VD/TL(,)p < 0.05), which was comparatively increased at 17 degrees C DT. Finally, the incidence of caudal-fin abnormalities significantly decreased (p < 0.05) with the increase of DT. To our knowledge, this is the first evidence for the significant effect of DT during the short embryonic and yolk-sac larval period on the swimming performance of the later stages.

Automated summary

The study found that temperature during early ontogeny has a significant impact on swimming performance and body shape of Gilthead seabream larvae, with potential consequences for later development. Additionally, temperature also affects the relative depth of the heart ventricle and the occurrence of caudal fin abnormalities.