Genetic evidence of killer whale predation on white sharks in Australia

Killer whales (Orcinus orca) have been documented to prey on white sharks (Carcharodon carcharias), in some cases causing localised shark displacement and triggering ecological cascades. Notably, a series of such predation events have been reported from South Africa over the last decade, with killer whales specifically targeting shark’s liver. However, observations of these interactions are rare and knowledge of their frequency across the world’s oceans remain limited. In October 2023, a 4.7 m (total length) white shark carcass washed ashore in south-eastern Australia, coinciding with reports from citizen scientists of killer whales hunting a large, unidentified prey item in the area. Visual inspection of the carcass revealed that the liver, digestive, and reproductive organs were missing, and the presence of four distinctive bite wounds, one of which was characteristic of killer whale liver extraction as seen in South Africa. Genomic analyses performed on swabs taken from the bite woun..., We collected genetic material from bite wounds on a white shark carcass by swabbing internal and external wound surfaces with a flocked cotton swab and preserving each in ATL buffer (QIAGEN). We collected a total of 15 swabs four distinct bite wounds, with each swab taken from a different area of each wound site. Samples were subsequently transported to the laboratory on ice and stored at 4oC for 24 h prior to genetic analysis. Total genomic DNA was extracted from the swabs using a QIAGEN DNeasy Blood and Tissue Kit, following the manufacturer's protocol with minor modifications as specified by Clark et al. (2023). We performed four negative extraction controls in parallel (all extraction steps performed but without a swab sample) to control for potential cross-sample contamination.
Polymerase chain reaction (PCR) targeting the mitochondrial 12S rRNA gene (106bp) was performed using a universal vertebrate PCR assay (Riaz et al., 2011; Table 1) following the laboratory workflow outlined ..., , # Data from: Genetic evidence of killer whale predation on white sharks in Australia

[https://doi.org/10.5061/dryad.r2280gbn5](https://doi.org/10.5061/dryad.r2280gbn5)

## Description of the data and file structure

### Files and variables

#### File: Shark_and_Killer_ASVs.xlsx

**Description:** Mitochondrial DNA haplotype sequences isolated from the bite wounds on the white shark carcass. These sequences were BLASTed against vertebrate haplotype sequences on the NCBI sequence archives to determine the taxonomic identity.

#### File: Metadata.csv

**Description:** Information on sample IDs, corresponding bit wounds and swab samples, and corresponding sample codes for which fastq sequence data is provided.

#### File: Sequence_data_Fastq.zip

**Description:** All sequence data for each biological sample taken from each bite wound on the white shark carcass

## Code/software

We performed bioinformatic analyses of the resulting DNA sequences from each bite wound following the analytic...,