Best fish roe to make caviar

…besides sturgeon and other protected/endangered fish. We’re tropical here and my choices are limited to: Japanese carp, eel, tuna, various members of the mackerel family, tilapia, milkfish (fam Chanidae, awa in hawaiin.)

Anything?

Salmon, trout or, if you really want to be classy - snail caviar.

Salmon and trout aren’t tropical, but have been introduced all over the place.
Snails are worldwide.

Or you could make fake caviar with spherification

A chef friend of mine has used this technique for food-beer pairings. He’s also used liquid nitrogen to prepare some foods, and served an amazing faux foie gras.

Science + cooking = yumm.

I’ve done it myself - Cointreau spheres piled atop chocolate tartlets, for instance, or balsamic spheres (with basil jelly noodles and mozzarella balloons as part of a deconstructed caprese salad).

But I think to do faux caviar, you’ll want something slightly sea-tasting and very salty for the caviar, like fish stock or maybe miso & seaweed soup.

I love the flying fish roe that you get in sushi bars: tobiko. It has a nice snappy bite, it’s salty and fishy and delicious.

I one had real sturgeon caviar, quite pricey, and I didn’t like it as much as tobiko. That’s good, because tobiko is much cheaper.