Tuna is a common fish in Malaysian cuisine. The local tuna is smaller in size than the ones we eat in Japanese restaurants or those found in colder waters. The local tuna is known as ikan tongkol and it's not an expensive fish to consume. There is another fish that looks almost the same, known as ikan kayu, and I wasn't able to distinguish between the two, until the fish monger placed them side by side. The local tuna, ikan tongkol's skin is actually bluish, looks pretty when the sun shines on it.
Ikan kayu has a much larger bloody area when cooked, tastes more fishy and has a drier texture.