Abstract
<title>Abstract</title> <p> This Data Descriptor presents a high-quality RNA-seq dataset profiling embryonic and larval development of Senegalese sole ( <italic>Solea senegalensis</italic> ) under three constant temperature regimes (14°C, 18°C and 21°C). A total of 48 samples were collected across eight developmental stages, from blastula to post-metamorphic larvae, and sequenced on the Illumina NovaSeq 6000 platform, generating approximately 30 million 150 bp paired-end reads per library. The dataset includes raw sequencing reads, gene-level count matrices and transcript abundance estimates (TPM), enabling comprehensive characterization of stage- and temperature-specific transcriptional dynamics. Technical validation confirms high data quality, with consistent sample clustering by developmental stage and biologically coherent differential expression patterns. This resource fills a critical gap in publicly available transcriptomic data for flatfish early development, providing a valuable foundation for investigating thermal plasticity, developmental regulation, and comparative flatfish biology, while supporting aquaculture research on temperature-driven phenotypic variation. </p>