Tropical Fish Hobbyist

Male platies like these can be clearly identified by their gonopodiums, but in immature males they may not be evident.

A

This is something of a reversal of gender roles, as you usually hear of situations where the male platy is females in overly aggressive breeding overtures. That makes me wonder whether your aggressive female is actually an immature male that hasn’t developed a gonopodium yet. It’s not uncommon for a platy that was believed to be female to suddenly reveal that it’s actually male. Of course, it could also be the case that you simply have an especially assertive female on your hands.

harassing

In either case, I think that, rather than banish the male to a different tank, I’d be inclined to see whether your dealer would be willing to exchange the aggressive specimen for another female platy, and then try again to establish a peaceful trio in your 10-gallon display.

Q

Brine Shrimp
and Nutrition

I’ve heard that brine shrimp have no nutritional value. Is

My fish love to eat frozen brine shrimp, so I hate to stop feeding it, but I don’t want to give them something that’s not good for them either.

that true?

Julie Pierce via email

across this

Dither Fish

What exactly is a “dither fish”? I’m new to the aquarium hobby, and I keep coming term in books and online.

Chuck Navarre

Wichita, Kansas

called naup

The nutritional value of live brine shrimp depends on when you offer them to your fish. Newly hatched brine shrimp,

lii, are generally considered to be more nutritious than the adults, because they are still carrying a yolk sac. After the yolk has been utilized, the shrimp’s nutritional value rapidly deteriorates. That’s why many hobbyists who culture live brine shrimp feed them some form of enrichment formula before offering them to their fish, and most fish food manufacturers enrich their frozen brine shrimp products with vitamins, spirulina, HUFAs, and so forth.

Even without such supplementation, though, I wouldn’t say that adult brine shrimp are completely devoid of nutritional value. They do provide some protein, and their chitonous exoskeletons serve as roughage. So while I wouldn’t rely on brine shrimp as a staple food, I would certainly include it as one element of a diverse diet that incorporates various dry, frozen, and fresh offerings.