Giant Clam Book

It was a lazy Sunday afternoon in the spring of 2011 when I met my friend Zeph at a pizzeria in Manhattan. He walked in waving his two favorite books: Giant Clams in the Sea and the Aquarium by James Fatherree and a tattered paperback copy of Advanced Reef Keeping by Albert Thiel.

Zeph had been a hobbyist for many many years and had even dabbled in freshwater fish breeding. His favorite animals at the time were the two enormous Gigas clams that were in his basement tanks.

Measuring a whopping 24" and 36", these two giant clams were an incredible sight! I was a newbie at the time and had never seen clams that large—not even in a public aquarium. I embedded a video I took of his tank near the bottom of this article. Zeph swore by that Giant Clams book—it was his bible for clam-keeping. For Christmas that year, Zeph gave me James Fatherree's book Giant Clams in the Sea and the Aquarium. And so began my awareness of Tridacnas and my desire to keep these incredible animals in my tank.

Like many of you, I did not have long-term success at first with ornamental clams in my aquarium. They had plenty of light and my water was dirty. Even so, they did not survive more than a few months. My last clam, Oreo, lived with me nearly four years.

During that time I also acquired a gorgeous ultra blue Crocea from a fellow hobbyist. That poor clam was unhappy no matter where I put it. In a final act of desperation, I went searching for James Fatherree and managed to connect with him on Facebook. I sent a few pictures of the clam and James diagnosed it as possibly showing pinched mantle disease. I followed his advice both from his book and what he was suggesting. Miraculously, the crocea began to feel better. Pinched mantle is not easy to recover from so this was very rewarding. The Giant Clam book was now a bible to me, too.

I was lucky enough to meet James in person at The Marine Aquarium Conference of North America a couple of years ago. He was gracious enough to sign my book for me. Meeting the author of a book I had poured over and hearing him speak of these incredible animals in person was a real treat. Over the next couple of days I learned a little more about his dives, his writing, his life as a professor, and about new research he was working on.

Fast-forward to today, I managed to track down a very busy professor to get caught up on all things Clam!

Gigas Clam

How did you end up writing a book specifically on clams?

I always thought clams were pretty neat but I really didn't know much about their biology. I was sure they didn't need to be fed in an aquarium, though. I'd had one for several years without giving it anything other than good water and metal halide lighting. I hadn't been adding any sort of plankton-in-a-bottle or other "coral food" to my aquariums and there wasn't even any available in the early- to mid-90s that I was aware of. So I was stumped around the turn of the century when I started reading in various places that giant clams had to be fed phytoplankton—regularly—in order to keep them alive. I knew that simply wasn't true. I had living proof.

I started doing some homework, looking for why my experience differed from widely-accepted opinion, and realized a couple of things. First, that there had been a tremendous amount of scientific research done on giant clam biology and aquaculture, and that little of the information was known to hobbyists. In fact, by the time I finished the book, I had printed out an estimated 3,000 pages of articles from scientific journals. And second, that Daniel Knop's book, Giant Clams, was the only book in print about them and caring for them in aquariums, and was also going out of print. Daniel had done a great job for the time, but a lot had been learned since he'd written it and it had become rather dated.

James in Japan

So, at some point I considered filling a niche by writing a new book on the subject, which would include as much information as I could muster from scientific and hobbyist literature, aquarium forums, and the experiences of other hobbyists I knew, as well as my own experiences as a clam keeper, seller, and aquarium maintenance business owner. Then, I moved to Japan in 2003.

It's a long story, but I moved to Japan and taught English there for a couple of years. The job was fun and easy, and I only worked about 20 hours a week. So, I had lots of free time on my hands, and now lived within a few hundred dollars of Okinawa and Indonesia. Both places had not only giant clams, but also had clam aquaculture facilities that I could visit. That’s when I made the decision and subsequently got to work, and I’m very happy that I did!

Why do clams have a high mortality rate in the home aquarium?

Of all the things that can lead to a clam’s demise, in my opinion, disease and poor lighting are the primary causes of death in aquaria. There hasn’t been a lot of work done on the diseases of giant clams, but oysters are a different story. Oysters, grown for food and pearls, are certainly a big-money global crop, and lots of money has thus been spent studying oyster-specific diseases.

It turns out there’s a long list of things that will stress or kill oysters, many of which are microbes. So, even though oysters aren’t the same thing as giant clams, I think it’s safe to assume there’s a long list of things that can stress or kill giant clams, too. Unfortunately, there’s not much that can be done about that in aquaria, either.

With respect to lighting, giant clams and corals often times have very different needs. While requirements can vary from species to species, giant clams generally need more light than corals do. Sometimes much, much more. So, I’ve found that a lot of hobbyists successfully growing corals wrongfully assume that they must have sufficient lighting to keep a clam. Oftentimes they don’t though, and clams slowly starve over a period of weeks or months without showing any overt signs of trouble. Then, they seem to "die for no reason." Read my article "A Look at "Mysterious Clam Deaths" on Advanced Aquarist for more information on this topic.

Giant Clam

Your thoughts on the best lighting for clams in the home aquarium?

As I pointed out, I think a lot of clam losses are due to insufficient lighting. So, I say go bright! Tridcana derasa and T. squamosa are oftentimes kept under fluorescent lighting with success, but that’s typically when there are several bulbs over a relatively shallow tank. Thus, in general it’s best to have metal halide lighting or use an LED system that is comparable in intensity. I’ll also say that I would NEVER try to keep T. crocea or T. maxima, two of the most popular species, under fluorescent lighting. The chances of long-term success would be almost zero.

Your favorite Tridacna?

T. derasa has been my top pick and most recommended species for years. This species usually isn't as fancy looking or colorful as some of the others, but derasas are categorically the hardiest clams of the bunch. Nobody knows why, but for whatever reason derasa has oftentimes thrived under fluorescent lighting. It grows relatively fast, gets pretty big, and can be placed on sand or rocks, too. So, it’s my fave.

Derasa Clam

Your thoughts on hybrid clams that are sold in the hobby—are these selectively bred or do they occur naturally?

In short, pretty much all of the clams that are sold in the hobby as hybrids aren’t hybrids. If fact, I’m not 100% that any of them are. I’ve seen a handful that may well be, but time and time again, others have turned out to be some natural variant of a given species, or specimens that have odd-looking shells because they were reared in tanks rather than on reefs. I gave a presentation on that at MACNA 2016.

Where was the largest Tridacna you found on your dives and how big was it?

Hmm. I’m not sure about the absolute largest, but I came across numerous Tridacna gigas on the Great Barrier Reef, several of which were easily over 3 feet in length. I’ve never seen so many big ones anywhere else.

Gigas Clam

Do you have a personal aquarium - if yes please describe it - size, how long has it been running, what do you have in it.

I’ve had as many as five marine aquariums in my house at one time, but now I’m down to just one. It’s a 125 gallon tank, which I’ve had running since shortly after my return from Japan in 2005. A couple of years ago it was looking great, and I’d never been happier with a big reef tank. But, I bought a new house and moved, and lost all of the stony corals to R.T.N. in the process.

The crazy thing is that I’d moved one or more reef aquariums from Alabama to Florida, then to Mississippi, then back to Florida over the years with no memorable loses – yet this time I moved 1 mile. I literally moved from one part of my neighborhood to another, and did everything right." But maybe three or four days after the move, I got up and went to work then came home to a tank full of dying corals. I'll never know what happened and it was quite saddening. I confess, since that happened I've had little interest in putting in the time and money to get it back to where it was, and have somewhat settled for a tank full of practically bulletproof soft corals.

Giant Clam

Here is a picture before the move. There are actually 8 fishes in there but I spooked them into the rock-work long enough to snap a pic. Check out my article "A Look at a Successful 125 Gallon Mixed-Reef Aquarium" on Advanced Aquarist about it.

Favorite diving spots?

I'll have to go with Bunaken, Indonesia and the Great Barrier Reef. Bunaken isn't easy to get to. The lodging is, let's say, primitive. There are no restaurants or convenience stores that I know of and there's pretty much nothing to do there other than dive. But the diving is spectacular! Bunaken has some of the highest marine species diversity you can see, if not the highest, anywhere on Earth.

Giant Gigas Clam


On the other hand, I was lucky enough to spend a week living aboard a dive boat jumping around the northern GBR and haven't seen anything that compares when it comes to the diversity of habitats. The reef structure, landscape, visibility, and current were quite different from place to place, with different areas having sometimes remarkable variability in what lived there. There were places with names like "The Clam Garden" and "The Snake Pit," too. You can guess what there was a lot of at each! Check out my article "On the Great Barrier Reef" on Advanced Aquarist for details.

Giant Gigas Clam

What is next for you? A new book? New articles? An upcoming dive?

I have an updated and much-improved edition of my book, Giant Clams in the Sea and the Aquarium, pretty much finished. But I ended up not getting it done and pushing forward with publication just yet. For one, I was working on a textbook for a while, which is finally done now.

On top of that, there has been a lot of giant clam research going on for the last few years, genetic/taxonomic work in particular, and some very interesting things have been discovered, with more in progress and on the way. So I've been waiting for a few things to get wrapped up before finishing the book. It won't be too much longer before it's finished and available, though.

Other than that, with e-books becoming increasingly popular and easy to self-publish, I'm thinking about putting together a series of marine aquarium books that'll cover pretty much everything to do with the hobby. I don’t claim to know it all by any means, but I know a heck of a lot of people in the hobby and industry and have pitched the idea to a couple of potential co-authors that would come on-board to help with a few topics. We'll see what happens…

I continue to write for several magazines in the U.S. and Europe. It's hard to believe that I've been writing for Tropical Fish Hobbyist since 1999 and haven't run out of things to write about. But that's the marine aquarium hobby for you. Lots and lots of subjects to choose from. I've accumulated several thousand aquarium/underwater photographs over the years, too. So I don't plan on stopping anytime soon. These days I'm more concerned with magazines going out of business than with me running out of stuff to write about and illustrate. The Internet has really put a hurting on them.

Diving? Well, it's looking like either Fiji or the Red Sea this summer. I'm not sure which one yet. I have a feeling I'll be happy going to either!