Tropical Fish Hobbyist - September 2008

animals—which pufferfish are—typically contain toxic substances within or on their tissues that will poison an animal that tries to eat them. Some poisonous marine animals, such as cowfishes and sea cucumbers, are capable of exuding toxins into the water when severely stressed or harassed, thereby affecting other organisms sharing the same water, but such is not the case with your puffer. Indeed, the dogface puffers Arothron spp., along with many other puffers, contain a very potent toxin called tetrodotoxin in their tissues. However, the only way your kids could be exposed to this toxin is if they try to eat their new pet.

Even though puffers aren’t venomous, I would caution your children to keep their hands out of the puffer’s tank—and never allow them to hand-feed it. Puffers may not have a deadly bite, but they do have powerful teeth that can inflict a painful wound, and they will bite the hand that feeds them.

Marine Fish Longevity

Hi. I’m 14 years old, and I’m setting up my first saltwater aquarium. I’ve been keeping freshwater tanks since I was 10. My question is about how long saltwater fish can live in an aquarium. The fish I’ve been seeing for sale are really expensive compared to freshwater fish, and I have to pay for any fish I get out of my babysitting money. I hope they live a long time!

Jade Stelzer

Champaign, Illinois

Q

Mark Smith

The orangespotted shrimp goby Amblyeleotris guttata.

The length of time a saltwater fish will survive in captivity depends on several factors. One factor is the age of the fish when it was captured (assuming the fish was wild-caught and not tank-raised). Obviously, a fish that has been around for several years or is nearing the end of its natural lifespan when captured won’t live as long in the aquarium as a young specimen will. It also stands to reason that your fish will have a longer lifespan if you choose healthy specimens to begin with.

Another factor is the particular species of fish you’re dealing with. Some, such as the neon goby Elacatinus oceanops, are naturally shorter-lived than others, typically living only a year or two in captivity. The water quality and nutrition you provide for the fish in your care will make a big difference in how long they live as well.

A

John O’Malley

Black-spotted dogface puffer Arothron nigropunctatus; though they are powerful biters that can deliver a painful wound to the unwary aquarist, dogface puffers are not venomous.

Choosing the right tankmates for your fish will also affect their longevity. For example, a peaceful, retiring fish kept with rambunctious and aggressive tankmates usually won’t live as long due to constant stress or outright physical bullying. Of course, keeping a small fish with a larger predatory species will significantly shorten the lifespan of the smaller fish—sometimes to just a few minutes!

That being said, many marine fish can live a surprisingly long time in captivity.

To give you a sense of just how long, I have a percula clownfish Amphiprion percula and a yellowtail blue damsel Chrysiptera parasema that have been around since you were about three years old, and they’re still going strong. While you can’t expect every fish you buy to live for 11 years, you can certainly make the most out of a fish’s lifespan—not to mention your babysitting money—by giving it the right care and protecting it from undue stress, aggression, or predation.