First Hybrid Genome Assembly of the Teleost Fish Red Cusk-Eel (Genypterus chilensis) from Oxford Nanopore and Illumina Reads: Comparative Genomic Analysis of Genypterus Species and Long Non-Coding RNA Tissue-Specific Expression

The red cusk-eel (Genypterus chilensis) is an endemic Chilean teleost fish of significant importance to fisheries and aquaculture; however, no reference genome is available for this species. In this study, we present the first hybrid genome assembly of G. chilensis using Nanopore long-reads and Illumina short-reads, integrated with structural and functional annotations from RNA-seq data of the intestine and head kidney. The resulting genome assembly was 439.89 Mb in size, with an N50 of 7.96 Mb, containing 35,029 coding genes. Comparative genomics with G. blacodes revealed high similarity in genome size and completeness. Additionally, 14,681 lncRNAs were annotated, with 641 lncRNAs and 7323 coding genes differentially expressed in a tissue-specific expression pattern. These findings provide a high-quality genomic resource that enhances the understanding of lncRNA regulation and genome structure in the Genypterus genus. This study establishes a foundation for future research on commercial traits, conservation, and the evolution of the Ophidiiformes order.