Pangasius sanitwonsei. A catfish which can grow to 3 meters length, but more usually found at just over a meter. It is less useful in cooking than many of its relations, being high in fat.
Grilled tilapia. Grilling in Laos is inclined to be long and slow, rather than the searing more popular in the West. This results in drier flesh than westerners might expect.
Featherback. A thin, silver fish with a marked row of dark spots running parallel to the anal fin. This is quite a bony fish but often pounded or scraped clean of the bones.
Noy tells me that these, which she calls "tuna", are imported and are very sought after. After further research, I think these are Indian mackerel, of the tuna family, a desirable fish for eating.