Tobies or Pufferfish

I prefer to use the name tobies, rather than puffers, to refer to fish of this group.

Q. I have a 55-gallon aquarium with some dead coral, some live rock and a large anemone. The tank has a trickle filter, a protein skimmer and a twin-tube fluorescent light with a daylight and an actinic tube. There is very little life on my live rock, and the anemone seems to be hanging in there (I have had it for 14 months).

I have a question about a fish I saw at a local shop that I would like to buy. It is called a blue-spotted puffer and I believe the scientific name is Canthigaster solandri. It has a reddish-brown body with iridescent blue spots and lines and an orange belly. I currently have a coral beauty angelfish (Centropyge bispinosus), a spotted hawkfish (Cirrhitichthys falco), a yellow tang (Zebrasoma flavescens) and a valentine puffer (Canthigaster valentini). They all do quite well together, but I am wondering if the blue-spotted puffer will fit into this fish community (I have heard both yes and no from different retailers).

What do you think, and can you provide information on this pufferfish? Do you think I could add more than one of the blue-spotted puffers to my tank? How many different species of Canthigaster can I keep in my tank? I enjoy your monthly articles on marine fish and wondered if you have ever written an article on pufferfish? Keep up the good work!

A. Well Todd you’re my kind of guy! I am also a fan of the members of the genus Canthigaster (which comprise the subfamily Canthigasterinae). I prefer to use the name tobies, rather than puffers, to refer to members of this group. This enables me to distinguish them from the “other” puffers, which belong to the family Tetraodontinae. The name tobies originated in Australia and is accepted as the vernacular name by most of the imminent ichthyologists. Some people also refer to members of the genus Canthigaster as the sharp-nose puffers because they have longer snouts than their cousins.

The fish you are actually interested in buying is probably Canthigaster papua. Now, before you chastise yourself for misidentifying the fish or throw away the book you used to identify it, you should know that Canthigaster solandri and C. papua were considered to be the same species up until recently. Now the two are recognized as two distinct species (Kuiter and Debelius 1994). Canthigaster papua, the Papuan toby, is known from the Philippines, Indonesia, New Guinea and Australia, while C. solandri is more wide ranging, having been reported from east Africa east to the Hawaiian and Line Islands. Another very similar species, the pearl toby (Canthigaster margaritata), is restricted in distribution to the Red Sea.

As you suggested, the Papuan toby is brown overall with blue spots on the sides of the body, blue lines on the back and the upper surface of the base of the tail fin, a black spot at the base of the dorsal fin and orange on the underside of the snout. The blue-spotted toby has spots on the side of the body, on the back and base of the tail fin, with some lines radiating from the eyes, and it has no or little orange on the ventral surface of the snout, head or belly. Both species typically have orange on the tail, but C. papuensis usually sports more orange.

Both of these tobies make excellent aquarium inhabitants. The biggest drawback with some individuals is that they will nip the fins of other fishes, often leaving circular bite marks on these appendages. Fortunately, most individuals do not engage in this undesirable behavior. I should point out that long-finned fishes, like the Platax (batfishes) species, are most prone to having their fins bitten than those fishes with less spectacular finnage.

As far as compatibility is concerned, the Papuan toby is a territorial fish, with males maintaining a harem of females. Some individuals will fight with each other if placed in the same tank. This is especially true of adult males. It is possible to keep a male with a female together in a medium-size aquarium, like a 55 gallon. As far as members of other species are concerned, it is usually not a problem keeping more than one toby species in a 55-gallon tank. However, males of different species will occasionally engage in combat.

You can tell if a Canthigaster valentini (I call this the saddled toby) is a male or a female by its coloration. Males have blue-green iridescent lines radiating from the back of the eyes, they have blue-gray lines on a light-orange background under the lower jaw, and a blue-gray patch in back of their anus. The blue-spotted toby also differs sexually in appearance and color — males attain a larger size and typically have fewer, larger spots than females. There also appear to be some size and color differences between the sexes in the Papuan toby. The individual in the accompanying photo was the larger member of a pair I observed for some time and is most likely a male.

Your two tobies will also be less likely to fight if the C. papua is larger than the resident C. valentini. I would avoid the temptation of adding another toby if the Papuan toby works out — I think you would pushing your luck!

Toby fighting usually begins with bouts of displaying, in which the combatants increase their apparent size by erecting a ridge on the back and belly. They perform these lateral displays to try and drive their opponent away without actually coming to blows. But, if one individual does not back down and leave the area, biting will usually ensue. This can result in severe injuries.

The problem with captive combat is that the fish that retreats cannot “leave the area” because an aquarium is so much smaller than the normal toby territory, and therefore this subordinate fish is chased by the more dominant or territory-holding fish. If it gets to the point where biting occurs you will need to separate the fish or risk losing one of them to injury.

You could try taking the dominant fish out of the tank and placing it in a different aquarium for a week or two, then try adding the more aggressive fish back into the tank and see what happens. In some cases the subordinate will accept its position in the pecking order from the onset and avoid the more dominant fish. In these cases lethal fighting usually does not occur.

Your other fish should leave the newly introduced Papuan toby alone unless, of course, it enters one of their preferred hiding places. For this reason, you should make sure there are plenty of shelter sites available. Hawkfish can sometimes bother small fish that reside near the substrate, but the toby is so much different in color and behavior that it will probably not cause any problems (you didn’t mention whether the hawkfish pestered you saddled toby). Also, if you are correct in your identification, Cirrhitichthys falco is one of the less aggressive members of this family.

The reason your live rock does not look too alive is because of the feeding habits of your saddled toby. All the tobies eat almost any sessile invertebrates (including sponges, corals, fanworms), tunicates and plant material, including coralline algae, that might grow on your rock. You have no doubt seen your toby inspecting and picking at the surface of the live rock. The rock actually provides a great supplement to the food you add for your toby, which should include a varied diet of chopped seafoods and vitamin-fortified frozen preparations.

One final tidbit — there are some very interesting mimic relationships that exist among several tobies and three filefish species. All of these are examples of Batesian mimicry, in which a toxic species is mimicked by a non-toxic form. The saddled toby is mimicked by the saddled filefish (Paraluteres prionurus), the pearl toby is mimicked by the Red Sea puffer mimic (Paraluteres arquat), and an undescribed monacanthid, known commonly as the spotted puffer mimic (Paraluteres sp.), resembles the blue-spotted toby. Good luck with your tobies, Todd, and happy fish watching!

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