Cape Kachese is the prominent headland on the north side of Nsumbu Bay and it is located inside the Nsumbu National Park, in northwest Zambia. At the top of the Cape, you will find Mpende Fisheries where they farm Oreochromis tanganicae. It is a full-scale operation where they hatch and raise fry in vats and ponds. Ultimately, they are moved out to Lake Tanganyika into giant fish cages, each one capable of holding 25,000 fish or 10 tons. I counted twelve large and several small cages in the water as we sailed by in the boat. It appears to be a successful operation, but I was disappointed to learn that 90% of the processed fish is exported. Although O. tanganicae is native to Lake Tanganyika it still gave me an uneasy feeling. Check it out on the satellite map, you can actually zoom in and see these fish cages in the lake.
As we entered Nsumbu Bay we stayed close to the northern bank, it looked like it would be good swimming place. Above the curved rocky shoreline there were lots of bushes and trees. There, at Cape Kachese I was hoping to see Petrochromis trewavasae, which is only found in the southwest part of Lake Tanganyika, and this was going to be my last chance on the trip. P. trewavasae are dark-brown, nearly black with a cream-colored pattern on their heads, and spots on their sides, older dominant males may lack this color pattern and appear all black. The finnage is amazing; dorsal, anal, caudal and ventral fins all have extensions. P. trewavasae is about 18-20 cm (7-8”) long and because of its smaller size when compared with other Petrochromis species it has been popular in the aquarium hobby for years. I have kept Petrochromis trewavasae myself and I was eager to see them in the lake.
Once in the water, I stayed pretty close to the shore, the rocks at Cape Kachese are about the size of your couches and coffee tables, piled 20 meters deep, or so people told me. I was bravely looking into each crook and cranny. I went around a big boulder and I saw a young adult Lepidiolamprologus, a couple Lobochilotes labiatus, Telmatochromis temporalis and a big bunch of Lamprichthys tanganicanus, the Tanganyikan Killifish. The killies were spawning and the cichlids were free loading off the killifish eggs. It was all happening on this unique rock; where part of the top had broken off and it looked like a stage, with a rock wall behind it. It was as if they were putting on a show just for me, in less than 1 meter of water, while I floated above hanging from a rock.
Lamprichthys tanganicanus is a beautiful fish, males are bright blue with yellow edges on the fins and they really sparkle in the sunlight. The males are large, 10-12 cm (4-5”) in length, and females are about half that size, and remain silver. It is easy to identify them by their fins, which are totally different from cichlids; it is the anal fin that is the show-stopper in this killie. They are quite interesting; they are labeled an egg scatterer and group spawner. When you see 12 – 15 killifish spawning at the same time, the eggs are flying all over. They spawn near the cracks in the rocks, and the goal is to fertilize the eggs as they roll down into a crack, where it swells up a little and stays in place until it hatches, and then the killifish fry swims out. It is not unusual to find all kinds of cichlids taking advantage of this treat. Lamprichthys tanganicanus are found throughout Lake Tanganyika and it is always fun to see them and to watch them spawn.
As I kept swimming north, I saw a couple of black flashes go in and out of rocks and I didn’t really think about it. But all of sudden I realized that maybe that was Petrochromis trewavasae. Then I saw another black fish swimming out of the rocks and sliding back in, but this time I saw a big spot on the anal fin. P. trewavasae have multiple egg spots, but it seems like one is always bigger and clearer than the rest. They are not just for looks either, since they are considered true ocelli, and actually it helps to guide the female to the male’s genitals in their spawning ritual. I was excited now, I thought I had seen Petrochromis trewavasae even if it was only a glimpse.
I had just been swimming in Katete and Chimba where I saw Tropheus sp. “red”, and then that I was south of Ndole Bay, I was anxious to see what the Tropheus sp. “red” was going to look like there. As I suspected, you could see the Tropheus moorii’s yellow influence. In the shallow water and in the sunshine, they were beautiful. You could easily see the yellow on the lower part of the flanks. I saw them in small groups of 5-6 fish. As I followed them across the rocks, they would stop and graze, I would look up and another 3-4 Tropheus would join them for a few minutes before all moved on. The juveniles were attractive; they have the T. moorii striping, with a bright red dorsal and anal fin. It makes you wonder how long this natural hybridization between Tropheus moorii yellow and Tropheus sp. red has been happening. I find it so interesting, and I was glad to be able to see it in person.
I was just swimming along, chasing the Tropheus and looking for more Petrochromis trewavasae, when I looked out and saw a school of Petrochromis fasciolatus. Wow, they looked nice there at Kachese. They have a dark-cream base with clear, defined striping. It was so cool to see them, this algae scrapper sometimes schools up in the afternoon and feeds as a group. I have seen this species before at other places in the Lake and I like to follow them if I can. They group up because they can get a lot more food with less effort than as a single fish grazing. I saw about 50+ in this group, they were away from the shoreline and I had to paddle out a bit to get a better view. I wanted to get closer and see if any of them had a red eye patch like they do up in Tanzania. But that didn’t work very well, they were immediately on to me, they headed down a few more meters, and then straight out towards the open water. Too far out for me, I had to let them go, but it was a joy to see them. We don’t have these fish in the hobby even though they are one of the smallest Petrochromis in the lake.
I saw many Variabilichromis moorii during that swim, they were everywhere in the shallow rocky habitat. I saw several pairs especially in areas where smaller rocks were piled on the larger boulders. The adult V. moorii are both black, with a nice blue fringe on the caudal and dorsal fins. It may be a common fish, but I never get tired of seeing a pair defend their fry.
I floated over the top of large flat rock, looked over to left and there it was, Petrochromis trewavasae. I was beside myself! He came out of a rock near the top of the water. I tried to swim backwards a little, because I didn’t want him to see me and dive back into the boulders. Then he was on the move about 2.5-3 m (8-10 feet) in front me, I followed him down over the rocks, he turned sideways a couple of times, and so I got a clear view. This large male was all-black, and his fins were flowing, complete with extensions. The body was tall, it certainly looked larger than any other I have ever kept, and I swear his prominent egg-spot was the size of a dime. As I stalked this P. trewavasae along the rocks, a large Petrochromis polyodon appeared out of nowhere, he didn’t really chase the P. trewavasae, he just nudged his tail to let him know he needed to keep moving. The P. trewavasae started to go deeper and then he slipped back into the rocks. Wow! That whole episode was only a few minutes and then he was gone, but what a memorable moment.
Every time I swim in Lake Tanganyika, I see something special. There at Cape Kachese, I had such a good swim that when I finally popped up my head up to look for the boat, it was more than a kilometer away. The Tropheus there were beautiful and it was awesome to see Petrochromis fasciolatus even if they did ditch me. I did the back stroke towards the boat so I could see where I had been and make sure that nothing was sneaking up on me, like 25,000 Oreochromis tanganicae! When I hit the deck on the boat I yelled, “Petrochromis trewavasae” and all my travel companions stood up and cheered!
It was another exciting swim in Lake Tanganyika!
© Copyright 2022 Pam Chin, all rights reserved
Chin, Pam. (Aug 09, 2022). "Cape Kachese — Zambia". Cichlid Room Companion. Retrieved on Oct 02, 2022, from: https://cichlidae.com/section.php?id=328.