which force conducted a morning strike during this battle?
The Japanese.
Battle of the Coral Sea
Believing that he had located the U.S. carriers, Hara, with Takagi's concurrence, immediately launched all of his available aircraft. 
what is the battle of the coral sea? A naval battle of 1942. which countries were involved in this? Japan versus the United States and Australia.
wiki:5428817
Battle of the Coral Sea [SEP] Morning strikes
ships bearing 182° (just west of due south), from Takagi. At 07:45, the scout confirmed that it had located "one carrier, one cruiser, and three destroyers". Another "Shōkaku" scout aircraft quickly confirmed the sighting. The "Shōkaku" aircraft actually sighted and misidentified the oiler "Neosho" and destroyer "Sims", which had earlier been detailed away from the fleet to a southern rendezvous point. Believing that he had located the U.S. carriers, Hara, with Takagi's concurrence, immediately launched all of his available aircraft. A total of 78 aircraft—18 Zero fighters, 36 Aichi D3A dive bombers, and 24 torpedo aircraft—began launching from "Shōkaku" and "Zuikaku" at 08:00 and were on their way by 08:15 towards the reported sighting.