Does transcriptome of freshly hatched fish larvae describe past or predict future developmental trajectory?

Transcriptomic analysis of freshly hatched fish larvae offers insights into phenotype development, yet it remains uncertain whether it reflects parental influence or predicts individual growth. This research scrutinizes the transcriptome of 16 Eurasian perch (Perca fluviatilis) larval groups alongside pre- and post-hatching traits. Despite consistent fertilization rates, significant variations in embryonic development and larval performance highlight diverse phenotypes studied. It enabled to bring our attention to the fact that larval transcriptome can serve as a window into both the parental contributions and the future performance of the larvae. Our further analysis shed light on ribosome biogenesis, neurogenesis, and the cell cycle, as important processes shaping early larval performance. Additionally, we propose a set of predictive, validated gene markers associated with further larval performance and key aquaculture traits, such as selenoo (associated with cannibalism), trim16 (Fulton condition factor), slc15a1 (specific growth factor), and cipc (final weight). This study delves into the descriptive and predictive nature of the transcriptomic portrait of newly hatched larvae, paving the way to comprehend the intricate developmental pathways from fertilization towards juvenile stage. ### Competing Interest Statement The authors have declared no competing interest.