Tetraodon biocellatus - Figure-8 Pufferfish eating some frozen Krill.
Take the time to master the art of the figure-8, and you’ll soon discover it is one deadly way to trigger strikes from big toothy fish.
The Figure 8 Puffer is a fairly small species, growing only as large as 3 inches at maturity. This fish is classified as aggressive, though primarily to members of its own or similar species. When housed with other fish, this species does fairly well. The Figure 8 Puffer is named for the unique patterning on its body. These fish have a white belly and a dark brown or green back with bright yellow lines and spots that form figure 8-like shapes. These fish are carnivorous and require a diet of brine shrimp, earthworms, krill, and crustaceans. To ensure that your Figure 8 Puffer lives a long, healthy life it is recommended that you purchase the fish as a juvenile and raise it with meaty, vitamin-rich foods.
The Figure Eight Puffer is a colorful little fish that is dark brown to green on the back with a white belly. It has greenish yellow patterns and spots on their backside that vary from specimen to specimen. A few black spots are outlined in yellow on the tail, body and nose, and the marking on either side of their caudal fins resemble the number 8, or an “eye spot”, which probably contributes to their name. It is virtually impossible to sex Figure Eight Puffers, but females are thought to grow larger than the males.
Figure 8 puffer fish-brackish water fish. I have one of these
figure 8 puffer fish guards dying crayfish
The Figure-8 suffers from too many names, both common names and scientific names. Currently, T. biocellatus is accepted as correct, but it has been called by several other scientific names, which actually may belong to distinct other species. In the trade the F-8 is frequently confused with the Ceylon Puffer (T. fluviatilis), which is well more than twice as long and several times the mass as an adult, and may or may not be less colorful at purchase. The Ceylon in my experience tends to have its colors fade a bit with age, while the Figure-8 does not fade at all. To differentiate the two fish, ignore the dorsal markings that give the Figure-8 its common name, and the dorsal saddle-like markings of the Ceylon, which can also appear to form a figure-8. Their colors at maturity are quite different, but that may be hard to detect at sale size when looking at live small fish in a store especially if you have only seen poorly reproduced pictures on the web or in books and magazines.These particular fish I tend to keep long-term in light brackish (~1.005 specific gravity). My personal feeling is that in general BW is intermediate between FW and SW for stocking purposes. If you subscribe to the "1 inch per gallon" rule for FW (highly debatable) and "1 inch per 5 gallons" for SW (equally debatable), this would put BW at 2-3 inches per 5 gallons. I do try to very roughly follow such a guideline for some BW species, but especially as puffers are such messy feeders, and considering territoriality plus activity levels I tend to be closer to but much more generous on water than SW stocking levels for the active hunter types such as Figure 8s. Total body mass of these chunky fish is large in relation to length, and territoriality is at or near the top of the scale. For me a single smallish immature F-8 might be kept in a ten in QT for some period, but for long-term housing, a visually complex standard 15 is far better, and a 20-long perhaps ideal for a singleton. Larger volumes make water management easier. These fish are adaptable to specific gravity variations by nature. They are not at all adaptable to reduced water quality. The same nitrification bacteria will continue to operate at these densities as well as at the lower QT densities. The bacteria needed at mid-range and high-range BW are different (those are the same as SW nitrification bacteria), but that does not apply for this fish and their optimum appears to be somewhere at or just over 1.005 specific gravity.