Grass Carp page:

"Personally I don't have a problem with the spines, As with most fish ..." Period before As?

Common Carp page: (As above)

Varieties of ... page:
"It's ability to survive in low oxygen environments made it possible to keep goldfish in fishbowls before the advent of areated acquariums." Its, aquariums.

"Actually, Vietnamese catfish is a genus known as "Shark Catfish" from its shape and is different from American Channel Catfish both in flavor and the shape of the fillets which are wider and flatter - bit it's still catfish, not sole." but

"This air breathing catfish quickly becomes a pest in subtropical areas. to another." Fragment.

"This one can easily be identified by the rows of yellow spots on it's underside and the rounder face" Its, Missing period.

"It's habits and characteristics are very similar to the Goliath Grouper of the American coasts." Its.

"This fish is endangered by pirate fishing and it's slow rate of maturing." Its.

(If you mean the contraction of "it is" or "it has", then use the apostrophe. Otherwise, if you mean possessive, leave it out.)

:-)

HTH.

Cheers,
Scott.