GUEST BLOG: Lake Shells...by The Lake Shore By Christopher Carpenter

Editor's note: This was in interesting blog written by fellow fish geek Christopher Carpenter, who works a lot with shell-dwelling cichlids from Lake Tanganyika. Christopher and I have had several discussions about the elusive (in the trade) Neothauma shells and the fishes which reside in them, and next thing you know, this interesting piece arose! Enjoy! -S.F.

My fascination with Lake Tanganyika, and its cichlids started early on in my journey into the aquarium hobby. Many of the cichlids have one-of-a-kind behaviors and appearances. The lake itself holds many wonders. One of its distinct features is the unusual water chemistry. For a freshwater lake, it has an extremely high pH, and high mineral content, leading to a unique phenomenon: “The shell beds of Lake Tanganyika”. Snail shells wash into the shallows, where they’ve collected for thousands of years, creating piles of shells, miles long, and anywhere from 10-30 ft. deep. In any other lake, these shells would slowly dissolve, but in Lake Tanganyika they become harder, and encrusted with calcium.

A distinct feature of cichlids is their ability to adapt, and many cichlids in Lake Tanganyika have adapted to call these shells “home” using them for shelter, and spawning sites. These fish are affectionately referred to as “shell dwellers” or “shellies” for short. Most often the shell of choice is that of Neothauma tanganyisence, because it is the largest mollusk in the lake. To use a snail shell as shelter, obviously, the fish must be small, and most “shellies” are very small. In fact, ‘Lamprologus’ multifasciatus, and ‘L.’ similis are tied for the title of smallest cichlid in the world, with females averaging just over 1” (2.54cm).  Don’t however mistake their diminutive size for a lack of strength or courage. In the National Geographic movie titled “Lake Tanganyika, Jewel of the Rift” a ‘L.’ multifasciatus can be seen biting the tail of a crocodile. I’ve had my hand attacked numerous times by various “shell dwellers”.

Many of the “shell dwellers” have found their own way to take advantage of these vast shell beds. ‘Lamprologus’ brevis for instance has found a way to reside in areas that have fewer shells, by male, and female sharing the same shell.  Telmatochromis temporalis has developed two distinct morphs, varying in size by the availability of rocks, or shells. Telmatochromis temporalis males average 4” (10.16cm), females 3” (7.62cm) while T. temporalis “shell” males reach approximately 3” (7.62cm), and females stay about 2” (5.08cm). ‘Lamprologus’ callipterus is quite possibly the most fascinating of all the “shellies”. In this species only the females are small enough to use the shells. Males can reach over 6” (15.24cm) in length while females stay close to 2” (5.08cm). Males need to be large to protect their territory, but they also use their size to steal shells from other males, often with females still inside the shell. ‘L.’ callipterus holds the title for “Male larger sexual dimorphism not only among fish- but across the entire animal kingdom.” Males typically weigh thirteen times more than females!

If you’re a stickler for a natural-looking aquarium, trying to use décor that the fish would see in their natural habitat, then you’ll want to know where to find Neothauma shells...Good luck! I found a dozen  specimens a few years ago, but they’re so small my fish ignore them.

Editor's note: We have a few specimens (the ones shown above)...and they're incredibly delicate...and quite small...and really expensive! -S.F.

The reason they are so hard to acquire, could be a couple reasons. One possible reason is that freshwater snails can carry “Schistosomiasis” also known as “Snail Fever”, a parasitic worm that can infect humans. The other probable reason is that the filter feeding Neothauma snail is at risk due to sedimentation. Deforestation along the shorelines has caused substantial amounts of sand, and silt to accumulate. Thankfully, there are many other shell options to choose from, including, Escargot, and Turbo snail shells.

If you’ve ever thought of keeping any of the many species of “shell dwellers”, I greatly encourage you to take the leap. If your lucky enough to find Neothauma tangayisence shells for them to reside in, just know I’m jealous. If you went to Lake Tanganyika to collect the shells yourself, know that I’m extremely envious, and wondering “Why in the world you didn’t invite me?”

Christopher Carpenter

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