Surprising as it is, the only transformation that occurred to Gadunka is solely that of size and nothing else. As per the ever vague Greg:
So yes, there’s an entire species of tiny angry men with big teeth walking on the ocean floor, and we’re questioning why squids don’t look normal.
This is a fair explanation, but the actual amount of physical alterations that occur could be very minimal. Brutaka was altered by the pit mutagen and barely changed at all, and almost all of the physical abnormalities the Barraki possess are explained away as being part of their species (except, of course, Kalmah’s third eye, which was blinded by Pridak before we ever met the character).
Also, on BS01, it cites Kalmah’s abilities and there’s one in particular to pay attention to:
Kalmah had five tentacles on the back of his head which could sense movement in the water. He had a long tentacle on his left hand, which he could use to manipulate objects and to attack. He was able to share memories with Sea Squid by touching tentacles with them.
Kinda sussy, but at the same time, that’s plural. Meaning the sea squid also have tentacles. So… Bizarre comic and set depictions aside, the Sea Squid not being squid due to the lack of tentacles is a moot argument because they very much do possess them,
And on a final note: the BS01 page for the sea squid literally calls them Squid-Like, not squids in an actual sense, so I don’t see why this question had to be asked. It’s the Bionicle universe; real-world rules need not apply.
His needs:
-bullet