While there were many different species of fish found in the Sea of Galilee there 3 types that were most commons adn they were the:
Musht or St. Peter's fish as it is called.
Biny
Sardine
It is thought that the fish Jesus divided were sardines. which are commonly referred to as "small fish"
From John Gill..
and two small fishes; there were but "two", and these "small"; it is amazing, that five thousand persons should everyone have something of them, and enough: these fishes seem to be what the Jews (c) call מוניני, and which the gloss interprets "small fishes": and by the word which is used of them, they seem to be salted, or pickled fishes, and such it is very probable these were; Nonnus calls them, ιχθυας οπταλεους, "fishes which were broiled", or perhaps dried in the sun; see Luk_24:42.
Okay, now that that is settled, what kind of barley loaves were they?