The eel ... the seal.
The eel is as long as the seal. / The seal is as long as the eel.
The squid ... the whale.
The squid isn't as long as the whale.
The seal ... the dolphin.
The seal isn't as long as the dolphin.
The dolphin ... the shark.
The dolphin isn't as long as the shark.
The squid ... the whale.
The squid isn't as long as the whale.
The shark ... the whale.
The shark is as long as the whale / The whale is as long as the shark.