For a limited time, get the Six Line Wrasse in FishVille. The beautiful specimen hails from the Indo-Pacific waters (the area in between the Indian and Pacific Oceans). It normally grows to a size of 10 cm in length and is said to occasionally make its way into aquariums.
During the next six days, your aquarium could be home to a Six Line Wrasse.
This little guy grows up in 12 days which means "low maintenence and big pay out!" Ten thousand coins to be precise. Not only that, you gain 600 experience! (Assuming you keep 'em alive)
The only downside? The Six Line Wrasse costs nine Sand Dollars.
Nonetheless, if this is the fish you've been saving your hard earned Sand Dollars for, don't wait, the Six Line Wrasse will not be here forever.