There are plenty of skulls and bones on alot of the wrecks the japanese did go and collect as many as they could, but as they only went to 40 meters there are still alot left deeper,they burnt the bones in a shinto ceromony performed at the blue lagoon, alot of the survivors make the pillgremage back each year to pay respects to there fallen comrades, i have alot of pics and video of remains but will not post them.
If this is the type of thing you would like to see ask your guide and he will find at least 1 skull for you, they hide them on the shallower wrecks. The dive that shook me up a little was inside the aikoko engine room, it is packed with human remains, some still in clothing such as bones coming out of shoes. Its a sobering experience to see/be where so many people spent there last seconds of life. 1600 men lost there lives on the aikoko alone. My personal feeling is to leave them alone, i talked about this with the guides and they agreed but also said they hide the shallow ones because they have seen scum try and remove teeth as souvigners!!
The attack was entirely from air, only 2 american craft where lost, 1 of which went into 2nd hold of the aikoko which was acting as a troop transport but also had amunition. The plane hit the hold with the ammo, the wreck is amazing, looking as tho it was cut in half with a knife, the front completly gone the back in pretty good condition. Not a single person from this ship survived.