Genomes of Endangered Great Hammerhead and Shortfin Mako Sharks Reveal Historic Population Declines and High Levels of Inbreeding in Great Hammerhead
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Academic Unit
College of ARts and Sciences
Publication Date
1-2023
Document Type
Article
Abstract
Despite increasing threats of extinction to Elasmobranchii (sharks and rays), whole genome-based conservation insights are lacking. Here, we present chromosome-level genome assemblies for the Critically Endangered great hammerhead (Sphyrna mokarran) and the Endangered shortfin mako (Isurus oxyrinchus) sharks, with genetic diversity and historical demographic comparisons to other shark species. The great hammerhead exhibited low genetic variation, with 8.7% of the 2.77 Gbp genome in runs of homozygosity (ROH) > 1 Mbp and 74.4% in ROH >100 kbp. The 4.98 Gbp shortfin mako genome had considerably greater diversity and <1% in ROH > 1 Mbp. Both these sharks experienced precipitous declines in effective population size (Ne) over the last 250 thousand years. While shortfin mako exhibited a large historical Ne that may have enabled the retention of higher genetic variation, the genomic data suggest a possibly more concerning picture for the great hammerhead, and a need for evaluation with additional individuals.
Journal Title
iScience
Volume
26
Issue
1
DOI
https://doi.org/10.1016/j.isci.2022.105815
Recommended Citation
Stanhope, Michael J.; Ceres, Kristina M.; Sun, Qi; Wang, Minghui; Zehr, Jordan D.; Marra, Nicholas; Wilder, Aryn P.; Zou, Cheng; Bermard, Andrea M.; Pavinski-Bitar, Paulina; Lokey, Mitchell G.; and Shivji, Mahmood S., "Genomes of Endangered Great Hammerhead and Shortfin Mako Sharks Reveal Historic Population Declines and High Levels of Inbreeding in Great Hammerhead" (2023). Faculty Authors and Creators Reception. 206.
https://opus.govst.edu/fac/206