North Towards the Kaiser: Part One

One of the most eye-catching cichlids north of Ikola is probably Tropheus sp. "kaiser." You can see them in the entire biotope, from shallow turbulent water down to deeper rocky areas near the sandy bottom. With its yellow band across the body you can't miss this species. They literally glow in the water. Tropheus sp. "kaiser"is probably the most common cichlid in this part of the lake. In the crystal clear water you can find them everywhere; swimming in small groups or grazing on the rocks that are scattered in the biotope. Their diet consists of loose algae that it finds in both shallow and deep waters. There has been some speculation about the yellow band on the Tropheus sp. "kaiser." According to Charles Darwin in his books about the origin of species, sexual selection is a determining factor regarding variations in color and form within species or between races. Surely the yellow color of the "kaiser" developed from a mutation in one or several individuals. This change, apparently, was considered as something more beautiful and attractive within the population. After some time the thing that started as a mutation has become the norm Consequently, the yellow color in the "kaiser" is the result of sexual selection which gives the most beautiful individual the best chance to multiply. The only boundary for the natural sexual selection is time. There are no other real limitations. Photo by Mikael Karlsson.

Poseidon Explorer had been lying on the beach for the last two weeks. Two old boat builders from Kabwe had been working at the camp with the boat all that time. New cotton in the seams between the planks and new ground color on the bottom of the hull had made the boat ready to be launched again. The soccer team in Kabwe, as well as some extra friends, had been hired to get the boat into the lake. The day after that we weighed anchor. It was towards the horizon in the north. We steered the boat north, towards the horizon when we left. We left our little harbor with feeling cheerful and optimistic as we began our trip to the district north of Ikola on Lake Tanganyika. At the Kabwe village we stopped to purchase some provisions such as onions and tomatoes. At the same time we could see the lake ferry Liemba coming in. It was going to anchor a couple of hundred meters outside the village. The Liemba was coming from Mpulungu in Zambia and Kabwe is one of the places where it has a stop. In the old days the ferry went all the way up to Bujumbura, but with the troubles in Burundi Kigoma has been the most northern stop.

Another cichlid from Ikola with a lot of yellow is Neolamprologus sexfasciatus. This yellow morph lives along the very long shoreline from Malasa Island in the south all the way up to Isonga in the north. Mixed in the population at Isonga you also find a few white individuals. This is not another species or race, but a sign of polychromatism. Neolamprologus sexfasciatus lives in the transition zone, stones mixed with sand, and you can often see a pair with a cloud of fry hovering above their territory which is often in the form of a cave. Photo by Mikael Karlsson.

It was ten o'clock in the morning when we set course towards Karema and the sandy banks at the Ifume River delta. The waves were already getting rough. Looking out at the lake you could see the crest of the waves breaking and forming white caps. We were traveling rather far out on the lake and we passed Karema almost without us knowing it. The water we traveled on was deep and blue-black. As we neared the Ifume River delta the color of the water became light turquoise and large groups of hippos were easily seen. Immediately north of the delta lies the village of Sumbwa and a few kilometers north is Ikola, the main village in the district. At both of these locations the shorelines are just sandy beaches. The next village in the northern direction is Isengule. Most of the underwater biotopes there are still just sandy surfaces. Directly north of Isengule is Kobogo and here there used to be rocky biotopes in the water. But today, when the lake's water level is a couple of meters (about six feet) lower than it used to be, the major part of these rocks are found on dry land. The first really underwater rocky area doesn't start until north of Kalya. The underwater biotope and the shoreline consist of alternating sand and rocks. The mountain slopes along the shore here are totally covered with cactus and small dried out bushes. When we passed these parts it had not rained for a very long time and was nearly unbearably hot. The only green vegetation was the cactus. At Kasalamnjaga there is a small bay that is ideal in which to anchor. Just outside the bay there are some large rocks emerging from the lake. These provide good protection against wind and waves. The whole stretch from Kasalamnjaga up to Isonga consists of almost only rocky biotopes. It was part of this region we should visit the coming week on Lake Tanganyika.

At the central east part of Lake Tanganyika lives a cichlid that originally was given the name Tropheus polli. On the other side of the lake, in the former Zaïre, there lives a very similar species with the name Tropheus annectens. Nowadays the scientists believe that these two variants are one species and that T. polli is a synonym to T. annectens. Tropheus annectens at Ikola is not as common as Tropheus sp. "kaiser." The reason for this is believed to be that the former is more recent arrival at this location and has not, as yet, been able to spread as much as Tropheus sp. "kaiser." But, in fact, T. annectens, to a large extent, lives on fine-grained algae. These algae exists only in shallow waters down to a maximum of two meters (six feet) depth, therefore limiting the environment that is preferred by T. annectens. Tropheus annectens is found all the way down to Ikola together with Tropheus sp. "kaiser." The rock habitat at Ikola and in the north consists of stones and rocks that most often are covered with a very thin and fine-grained layer of sand. It seems that Tropheus sp. "kaiser" tolerates this sand rich algae better than T. annectens. The latter species is often observed grazing algae from rocks that are completely free from sand, such as the vertical surfaces on the rocks or the totally sand free stones in very shallow water. In general, you could say that the relationship between the number of individuals of Tropheus sp. "kaiser" and T. annectens is in proportion to the amount of loose-sand algae and the amount of clean or fine-threaded algae. Photo by Mikael Karlsson.

From 2:00 a.m. until 4:00 a.m. I was lying awake philosophizing about the cold. It was terribly cold. Although I was incredible tired I could not sleep. I was so cold that I was shaking although I was wearing socks, jeans, a T-shirt and two pair of long sleeved sweaters. On top of that I was lying on a double bed mattress with an old blanket over me. It had started to blow rather hard later in the night. My place on the boat was by the gunwale at the starboard side. The wind was coming from the north and was first felt by the starboard side and the people that were sleeping there. At 1:00 a.m. Krispo and Marko went up to change water. We did not have many fish at this time, so the water change, made with a noisy gas-powered engine, was done relatively quickly. At 4:00 a.m., I managed to get some sleep and I slept until 6:00 a.m. when the cabin boys Vittus and Stahili started to make the morning chipati bread. But they were not that lively in the morning. It takes a long time to make bread for the whole crew. That's why they have to start so early. At 6:00 a.m. it was still pitch dark outside. On board we had a small fluorescent tube spreading a nice glow. It was an ideal to be on the lake early in the morning. The wind had decreased to a gentle breeze and the delicious scent of newly baked bread was coming from the stem. At 6:45 a.m. The sunrise was on its way and as the sun became brighter and brighter the rest of the crew awakened. By 7:30 a.m. there were 20 newly baked Chipati ready to be served together with a steaming cup of tea. I mixed in a lot of sugar in the tea to at least get some kind of energy. Then it was time for the blessing of the morning, namely a cup of strong black coffee.

Directly north of Ikola at the villages of Isengule, Kobogo and Kalya, you find a unique variant of Simochromis babaulti. At this location there is a very yellow population. North of these bays at Kasalamnjaga, the yellow color fades to a more ordinary color. The populations at Ikola are somewhat special for another reason, as well ten years ago, when the water level was at least a couple of meters higher than today, the underwater biotope was much larger and housed many more fish. At that time we not only caught S. babaulti, but also Tropheus sp. "kaiser." The latter species at Ikola is now present only in an incredibly small population. The underwater biotope at the location consists nowadays mostly of sandy surfaces with some scattered stones and rocks. On land, however, there is a long row of rocks along the shoreline. Photo by Mikael Karlsson.

We had anchored the boat at an excellent place. We did not have to move the boat to get to the collecting location since we were already there. After breakfast we therefore started to prepare the diving equipment and the collecting equipment. At half past eight all the divers were ready and could start with the main task for the day. I was soon ready, too, to join them. I was a little bit too eager though and missed some important details. The tubes were not correctly fastened to the diving west, and it was loose on my back until I tightened the strap. I also did not prepare my mask before I dived in, so it fogged up and my vision was worse that it would have been without the mask. To be able to clear the mask underwater a peculiar technique is needed. You take your mask off, take out the regulator from the mouth, put the mask against the mouth and make sure that you get the saliva on the inside of the whole glass. You can't just spit, you have to put your lips to the glass or quite simply lick it. Another way is of course to go back to the surface and do it the regular way by spitting in the mask. Also, there was some dirt in the connection of the low-pressure hose to the diving west. The hose was leaking and filling the west with air. I gradually became more and more buoyant. When I realized what was going on, I simply disconnected the hose. When all the mistakes were corrected I was finally able to study the dive site.

At Ikola and all the way up to Isonga there are two species that are champions at living in the shallow wave zone, an environment with a lot of water movement. The more common of these two cichlids is Eretmodus cyanostictus. This species is found in very shallow water, from a couple of decimeters (about eight inches) down to a depth of five meters (16 feet). In this shallow turbulent biotope the main food source is fine-grained red-brown algae. Below two meters, where this thread alga doesn't grow, the food supply constitutes of light and loose algae. Photo by Mikael Karlsson.

Everybody was in full swing early today. The clock was barely 8:00 a.m. when I first hit the water. At first I swam past the shallow place outside the anchorage, just southwest from us. Here the water was only a half-meter deep and the waves were extremely strong. There were a lot of pebbles on the bottom and I could observe a few red Callochromis melanostigma mastering the waves. I continued out towards deeper water to escape the waves. I struggled past the 20-meter (66-foot) long stretch of half meter (18-inch) deep water. My equipment was quite bulky with a lot of it exposed to the surface swells. When it was deep enough I turned to the south and finally found the zone between sand and rocks. In this intermediate zone I could see Neolamprologus gracilis eating plankton. It was about 8 meters (26 feet) deep at this location and the group in front of me consisted of less than 10 individuals. In the sand just outside the rocks there were big schools of Enantiopus melanogenys, Xenotilapia flavipinnis and Grammatotria lemairii. Suddenly, I had three half grown Hydrocynus vittatus ("tiger fish") in front of my mask. They were studying me from a short distance, hesitantly. Soon they were frightened by the sound of the regulator and they dashed away.

Tanganicodus irsacae is the other species found in the wave-washed zone. Because T. irsacae is well suited for turbulent water, you can also find it in relatively shallow waters. Unlike E. cyanostictus, T. irsacae is not a plant eater. It lives, instead, on small invertebrates, especially aquatic insects. These insects are very scarce in the turbulent and sediment free biotope, therefore you most often find T. irsacae in water 2 to 6 meters (6 to 20 feet) deep. E. cyanostictus has a broad and powerful mouth to make it possible to scrape algae randomly from rock surfaces. T. irsacae, on the other hand, has a narrow mouth with sharp teeth that are well suited for picking insects and small invertebrates. It searches for its prey all the time, only occasionally seeming to find something edible and then it bites against the surface. Insect larvae may be more abundant in the calm deeper waters rich in sediment, but since T. irsacae needs oxygen-rich water, you never find it in deeper biotopes. Photo by Mikael Karlsson.

All the newly caught fish had to be identified, counted and sorted before the divers could have their lunch. It was also important to check the size of the collected fish. During this collecting trip we had been concentrating on Tropheus sp. "kaiser"When it was time for sorting this was the procedure that was used. One holding cage at the time was emptied into a net with an area of about one square meter (nine square feet) which was placed in a water filled thousand-liter (264-gallon) tank. The number of fish that was put into the net each time varied between 10 and 15, depending on the size of the fish. In this case the contents of the holding cages was mainly Tropheus sp. "kaiser," and therefore we could put 20 fish in the net for each sorting round. Mwalimu was managing the identification and sorting, Marko kept notes and John and Krispo collected cages and put the fish into the net. Each fish had to be sexed before it could be put in the right tank. It was also important to sort away all the small Tropheus sp. "kaiser," at this early stage. Only the largest animals are of interest to us. It would be disastrous to the native population to also collect small animals. If half-grown fish are left to live in nature another year they will make sure that the population survives. Otherwise you have to hope for the small fry to keep the genes in the population intact, and they are a very suitable class="caption" food for predators. The sorting work was proceeding well. Fat Tropheus are always easy to sex, which is not always the case with thin or smaller individuals. The fish were counted and placed in different tanks. The small individuals, which were probably caught by the less experienced divers, were simply returned to the lake. You can keep a lot of Malawi cichlids in a thousand-liter (264-gallon) tank with fresh lake water and with regular water changes every other hour. But with the Tanganyikan cichlids in general, and especially Tropheus, it is another story. A maximum of 100 newly caught Tropheus in each tank is what you can have, and that implies that the water is changed at least twelve times every twenty-four hours.

The species is one of the many geographic variants of the Neolamprologus brichardi group that is found throughout the lake. Neolamprologus gracilis is found from just north of the Ifume River delta all the way to Bulu point. This areas includes Ikola, Isonga, and the Mahale Mountains. It is rather rare and is never present in large shoals, only in groups of eight to ten individuals. You find it in the transition zone at a depth of barely ten meters (33 feet) where they are living on zooplankton. Photo by Mikael Karlsson.

Rocking boats and glittering waves. Summer breezes that slowly swept along the coast. The sun was shining from a cloudless and clear blue sky. We were collecting fish by the village Rwega. The village people were standing on the beach. This was the setting for our collecting activities. The water at the rocky shores north of Ikola is a blessing to dive in. It is crystal clear and bright. The rocks stretch, in most cases, not deeper than 10 meters (33 feet). But it is a turbulent biotope with waves from the open water of the Lake crashing over. At a couple of meters (six feet) depth the heavy swell is perpetually making itself felt. Here it is not as much sediment on the bottom here but in certain places, where the waves are strong, the sand is constantly whirling up from the bottom. The sunbeams were penetrating way down in the water so you could actually see them. Knife sharp beams projecting themselves on the algae covered rocks and the yellow Tropheus sp. "kaiser" were lighting up the biotope even further. In shallower water you could see Ophthalmotilapia ventralis flutter around above rocks in this turbulent environment. This variant is almost as completely neon blue as the race that lives immediately south of Ifume River at Karema down to Kasombe. In deeper waters over rocky habitats you find Ophthalmotilapia nasuta where it scrapes loose growing algae from the rocks. The variant at Ikola is completely black with a yellow section on the belly and with yellow pectoral fins. In the shallowest biotopes there were only stones, free from sand and sediment. T. annectens is more common in this biotope than deeper down. Among the sand between the big rocks scattered on the bottom of the lake and you could observe many Xenotilapia sima.

Two species from this genus that are often classified as strictly sand dwelling are consistently found in the rocky biotope. These are Xenotilapia spilopterus and Xenotilapia sima. The later species, however, is very common in both sand and rocky biotope. When diving at Ikola and north you find both species most often in the rocky biotope, sometimes with some elements of sand between the rocks. X. sima is attractively colored with yellow fins and a shimmering lilac body. Photo by Mikael Karlsson.

I returned to the boat when the dive tank was nearly empty. Powerful waves from the lake were rolling in where we were anchored. It was clear that the anchor, supposedly in the sand on the bottom of the lake, had come loose. Suddenly our boat, Poseidon Explorer, rapidly started to drift towards the shore. Omari, the only man on board, hauled up my diving gear. Then I tried to get the boat towards open waters by pulling the anchor line. The only thing I succeeded with was to pull the anchor towards the boat since the anchor was sliding on the sand. Omari pushed long bamboo poles down in the water against the bottom and tried to get us out from the beach. But the vessel was not affected by the power of such few men. When the hull hit the bottom and the waves were coming in broadside we were forced against the beach even harder. The depth was now just a couple of decimeters (about 8 inches) and was too shallow to put the outboard down into the water. The hull was pounding constantly against the bottom in pace with the waves and the boat was rolling heavily with each wave that swept in. The equipment on board was soon scattered all over the deck. This happened at noon and that was lucky because now the rest of the crew came swimming towards the boat. John was assigned the task to dive and locate the anchor and then fasten it in the sand bottom or against a rock. At the same time the rest of the divers were pushing the boat out until there was about a meter (three feet) of water under the boat. With ten men working we brought and end to our crisis. After that it was time for a lunch break and some food. The divers were eating common maize flour and boiled beans. We did not have time to roast any fish. On the remaining heat on the glowing coals I managed to sizzle up some onions and tomatoes. But the maize flour is not a highlight in the history of cooking, so I boiled up some spaghetti instead. To conclude the lunch tea and one coffee was served.

Particularly at Ikola and just north of the other places where you find the yellow S. babaulti there is also a honey-yellow variant of Aulonocranus dewindti. It is strongly restricted in its distribution and the population is not big. At Mpondogoro there is a population where the males are dark blue with two yellow spots on the belly. Also this population is unique and relatively small Males of A. dewindti will create a deep and narrow crater against a rock. Then they hover slowly about half a meter (18 inches) above its territory looking for females or other males nearby. They live in the transition zone at a depth of less than 10 meters (33 feet). They feed on invertebrate in the sand. Their heads have relatively large cavities and sensitive sensors. With the help of these they can listen and feel the movements of small animals that hide under the surface of the sand. Photo by Mikael Karlsson.

Petrochromis ephippium lives almost throughout the entire lake, with a few color variants in various populations. It has been called "saddle-fleck trewavasae" and "moshi yellow." From Cape Mpimbwe a variant called Petrochromis sp. "golden moshi" has been exported to Sweden along with another race with the name Petrochromis sp. "moshi orange" from Cape Kibwesa. All of these variants are the same species. At Ikola, and at many other places along the east part of Lake Tanganyika, there is a yellow variant of P. ephippium. Young individuals are brown with a yellow spot on the back, just below the dorsal fin. Most of these individuals have also close stripes over the body. but these stripes fade when the fish matures and the yellow color takes over. Even large females are yellow, at least the females that are not brooding. P. ephippium tolerates a varied biotope. You find it on the rocky biotope in shallow water as well as in deeper water near the transition zone and the sandy bottom. You can see it scraping algae from rocks covered with a thin layer of sand as well as from stones with no sand cover at all. Photo by Mikael Karlsson.

Poseidon Explorer has a weigh of almost 5 metric tons when it is not loaded with gear. When we have a lot of fish on the boat, and therefore also a lot of water in the plastic cans, it is a heavy ship. In extremely bad seas, when the waves force the ship into pitches, rolls and swinging movements, the crew is not a cheerful bunch. When the boat is not totally loaded with water, or in calm water, it glides along gracefully through the waves. Since this was in the beginning of our collecting trip the boat was lightly loaded. Although the water was rather rough on this trip, we progressed peacefully crossed the waves back to the shore at Rwega.

In the shallow transition zones north of Ikola, Petrochromis fasciolatus is rather common. At these places you find a color variant that is one of the most interesting of this species. It has been frequently as "neon eye." This name alludes to the neon red eyes that is highly colored and conspicuous in the lake. You can see this species move through the biotope in big shoals. In this way it can eat algae on rocks that is situated in territories of other aggressive species. These shoals sometime consists of many hundreds of individuals. It is surely a remarkable sight when such a big group shows up. As a diver you can get really close if you move cautiously towards the shoal. It has been observed that Petrotilapia genalutea in Lake Malawi has a similar behavior as P. fasciolatus, regarding the way they plunder other males' territories. Photo by Mikael Karlsson.

As it started to become evening it was time for some food. We were eating rice and roasted fish; Petrochromis sp., Lobochilotes labiatus and Boulengerochromis microlepis. From a clump of trees down by the beach we could hear a sound like a howling alarm. The crickets were out. From a small tape recorder that we often take on our trips, we had different and more welcomed sounds. It was the most bizarre parts from a Swedish comedy act the we play to amuse ourselves. It was most beautiful at twilight. The clouds over the lake had decreased. The last light from the sky was gleaming on the water surface. The sun was quickly sinking down on the horizon. Shortly after that it was completely dark.

Lamprichthys tanganicanus at Rwega, Ikola. Photo by Mikael Karlsson.

References Cited

• Konings, Ad, Tanganyika Cichlids in The Cichlid Yearbook, Vol. 1-6. Cichlid Press.
• Konings, Ad, Back to Nature Guide - Tanganyika Cichlids.
• Karlsson k Lundblad, North towards the Kaiser, Ciklidbladet No. 1, 1991.