Thanks for your input.
There are some records of the Japanese bombers that made counter-attacks (the USS Intrepid had to sail back to Pearl Harbor for repairs after being hit by a torpedo), but I'm interested in the fighters that went up to defend the laguna against the USN fighters. From what I've found so far, there are no indications that there were any other fighters than A6M zeros.
Interesting statment about the 'Zeke' codename. Different sources claim it was the official allied codename for the Zero. Here's what I found about that on wikipedia:
Quote:It is universally known as Zero from its Japanese Navy designation, Type 0 Carrier Fighter (Rei shiki Kanjo sentoki, 零式艦上戦闘機), taken from the last digit of the Imperial year 2600 (1940), when it entered service. In Japan it was unofficially referred to as both Rei-sen and Zero-sen. The official Allied code name was Zeke (Hamp for the A6M3 model 32 variant); while this was in keeping with standard practice of giving boys' names to fighters, it is not definitely known if this was chosen for its similarity to "Zero."
It must be said, though, that the Japanese planes look very much alike (except for the Tony and maybe some earlier fighter types), especialy to unexperienced eyes. It's very possible that some Allied pilots called every Japanese fighter they spotted a 'Zeke'.