High-quality genomic resources are essential tools for conservation and management actions. We present a chromosome-level genome assembly for the false killer whale (Pseudorca crassidens, Owen, 1846), a large globicephaline delphinid found in tropical and subtropical waters. The final genome assembly is 2.7 Gb, with a scaffold N50 of 110.1 Mb, organized into 21 autosomes plus X and Y sex chromosomes. BUSCO scores were 97%, with low levels of duplicated and fragmented annotations. Repetitive elements were a larger proportion of the genome relative to most previously published cetacean genomes. Using this reference, we compared trends in historical demography and genome-wide heterozygosity in two North Pacific populations of false killer whales using short-read data mapped to the reference genome. Modeling of historical demography in these two populations indicate similar fluctuations in effective population size over time, reflecting shared ancestry until ~ 100-200 kya. Genome-wide heterozygosity levels were moderate relative to other cetaceans. The new genomic resources can facilitate further research on comparative genomics and can serve as a reference for other globicephaline cetaceans that currently lack chromosome-level genome assemblies.
Citation:
Hernandez, K.M., K.K. Martien, R.W. Baird, M.T. Schmitz, M.S. Springer, J. Gatesy, J. Mountcastle, T. Tilley, L. Abueg, N. Brajuka, J.R. Balacco, O. Fedrigo, G. Formenti, E.D. Jarvis, and P.A. Morin. 2026. Reference Genome Assembly of the False Killer Whale (Pseudorca crassidens). Journal of Heredity: esag031. doi: 10.1093/jhered/esag031
Link:
https://doi.org/10.1093/jhered/esag031