Megamouth shark its food. A relatively poor swimmer, the megamouth has a soft, flabby body and lacks caudal keels. The megamouth is considerably less active than the other filter-feeding sharks, the basking shark and the whale shark. The megamouth has a stout body and a long, wide bulbous head. Megamouths are large sharks, able to grow to in length. Males mature by and females by . Weights of up to have been reported. As their name implies, megamouths have a large mouth with small teeth, and a broad, rounded snout, causing observers to occasionally mistake megamouth for a young orca. The protruding
Pain in fish that the absence of C-type fibres in cartilagenous sharks and rays indicates that signalling leading to pain perception is likely to be impossible, and the low numbers for bony fish (e.g. 5% for carp and trout) indicate this is also highly unlikely for these fish. Rose concludes there is little evidence that sharks and rays possess the nociceptors required to initiate pain detection in the brain, and that, while bony fish are able to unconsciously learn to avoid injurious stimuli, they are little more likely to experience conscious pain than sharks. A-delta-type fibres, believed to trigger avoidance reactions, are common