All about Gobies by Dr Klaus Stiefel

Another great blog from biologist and underwater photographer Dr Klaus Stiefel. If you wan’t to tap into Klaus’ encyclopaedic knowledge or marine life in Malapascua join him as he hosts our annual Photo and Marine Workshop here at Evolution in September. Your photography skills and appreciation of the marine world will never be the same!

Everyone comes to dive in Malapascua for the elegant thresher sharks, and who wouldn’t be fascinated by these noble predators. But, there is also much to admire at the other end of the fish size scale: Malapascua has many beautiful, tiny gobies. These minute fish are in fact some of the smallest known vertebrates (animals with a backbone), and in the coral crevices, on the sponges and in the sand of Malapascua’s reefs there are many of them to admire. Gobies are often colorful and fantastically painted, and many of them display a number of very interesting behaviors.

Certain gobies live in the sand, usually in pairs. These gobies occupy a burrow, which they dig themselves, without the help of a shrimp. The right one is just picking up a mouth full of sand to sip trough for something to eat.
In 2011 Matt and David and I conducted a study of the gobies of Malapascua which is now available online. The goal of the study was simple, yet ambitious: let’s see how many different species of gobies we can find in Malapascua and on the adjacent Monad Shoal, and see at which depths they live. And since we are all super awesome tech divers (I was taught by Matt & David)!, we sampled the gobies down to 60 meters.

We found an amazing number of different species, 59 of them! Two of them were even previously unknown to science. I took pictures of them, but to really describe them and name them as new species, we will have to catch one from each species, and send them to an expert. This is a plan for future expeditions, and so far David, Matt and myself are the only people on the planet to ever see one of these fishes. Amazing, isn’t it? If anyone wants to donate a rebreather to me for this aforementioned future expedition, please get in touch with me!

The gobies were not randomly distributed in the waters of Malapascua. Some gobies are associated with digging shrimp in an interesting symbiosis: the shrimp dig a shared burrow in the sand, and the goby with its superior eyesight keeps a keen watch for oncoming predators. Hence the shrimp is safe during its excursions to the surface, and the goby has a spacious burrow to retreat to. Both partners benefit. These shrimp gobies are much more prevalent near Malapascua, where shallow bays protect them from the strongest currents. The ripping currents on Monad make the shrimp-made burrows in the sand too unstable, and the shrimp gobies and their crustacean partners can’t settle there.
In contrast, on the steep walls of the Monad shoal, hovering gobies were much more abundant, and the newly discovered species were of that type.

We also found a new type of mimicry. What is mimicry? It’s when a harmless animal deceitfully looks like a dangerous one. One example are the harmless flies which share the black and yellow coloration of wasps. Any predator will think twice about munching such an insect with a warning color, and the falsely advertising flies are also spared. Mimicry is also abundantly found in the ocean. We found a goby, Hector’s goby (Koumasetta hectori), swimming in-between a school of cardinalfish (Apogon nigrofasciatus). The goby’s coloration was very similar to the cardinalfish’s, with alternating black and yellow stripes. But not only that: the goby had a false eye spot, looking like the cardinalfish’s eye, near its tail, making it look like a cardinalfish looking into the other direction. Why is it beneficial for the goby to be mistaken for a cardinalfish? I don’t know, maybe this species of cardinalfish is poisonous, to the best of my knowledge this is unknown. Another topic for future studies!

In addition, we often found that particular goby in-between urchin spines, where it also blended in well with its black stripes. The coloration of Hector’s goby is useful in two separate ways!
Many of Malapascua’s gobies are exquisitely colorful, with the coloration probably important in recognizing fish of the same species. So, the next time you descend around Malapascua, keep your eyes open for some of my goby friends! And if you enjoy my raves about life in the ocean, why not join me at the Evolution Photoganza in Malapascua in September?