shark.plodive.com has no CNAME records.
Question and response
Question
dig shark.plodive.com. NS
Answer
The response has no answer records.
Authority
plodive.com. 3278 SOA dns.plodive.com. hostmaster.plodive.com. 1951591616 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0