import csv


def get_mt_seqids(blast, min_blast_length):
    """Get candidate mitochondrial sequence IDs from the BLAST file"""
    seq_ids = []
    with blast.open("r") as f:
        tsv = csv.reader(f, delimiter="\t")
        for row in tsv:
            alignment_length = int(row[3])
            seq_id = row[1]
            if alignment_length >= min_blast_length:
                seq_ids.append(seq_id)
    return seq_ids