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African Diving Ltd
African Diving Ltd - Ichthyological surveys of Tanzania
African Diving Ltd - Ichthyological surveys of Tanzania
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Tropheus in Mtosi Bay (HD video footage)

In 1990, while surveying the areas of Namansi Bay and Mtosi Bay, we found a type of Tropheus with a striped body and dorsal fin of a mainly yellowish colouration. This was a Tropheus moorii-like species which was referred to as “Yellow Rainbow”. Based on the geographical distribution (extending along the southern Tanzanian coast of Lake Tanganyika, between Katale Bay and Pinga Point, a distance of about 20 km, or 30 km along the shoreline of capes and bays) and the disagreement of the diagnosis of Tropheus moorii, it is now considered to be a fairly distinct variety, referred to as Tropheus cf. moorii “Katale Bay-Pinga Point”.

In 1991, further surveys of the same areas followed. At the northern side of Mtosi Bay, we noticed that numerous individuals of Tropheus displayed a more reddish colouration. In particular, the dorsal fin, but also partially the flank of the body, appeared red or reddish. These reddish individuals – which later were referred to as “Red Namansi” – co-existed with the ordinary yellow individuals. The appearance of individuals with a reddish dorsal-fin colouration was found to be restricted to the northern side of Mtosi Bay.

In Mtosi Bay, a second Tropheus species is found, referred to as Tropheus sp. “Mtosi”, also called “Fiery Fry”. Tropheus sp. “Mtosi”, which is limited to the area of Mtosi Bay, is unique due to a combination of characteristics that include an orange or reddish colouration, possessed by sub-adults and juveniles.

Furthermore, in the same locality (Mtosi Bay), a few individuals with a very unusual colouration have been observed (Karlsson and Karlsson 2016). These individuals seemed to display characteristics of both of the two co-existing species, i.e. T. cf. moorii “Katale Bay-Pinga Point” and T. sp. “Mtosi”, and likely they are the results of hybridisation between the two aforementioned species. If so, then a possible explanation of why T. cf. moorii “Katale Bay-Pinga Point” is rather variable at the northern side of Mtosi Bay, which includes the appearance of the ‘morph’ “Red Namansi”, would be a present, or historical, hybridisation, or, perhaps more precisely, the occurrence of a gene flow of a particular gene or genes, from one species to another, due to the reproduction involving a hybrid (of an increasingly young generation) and one of its parent species, a phenomenon known as reproductive backcrossing, or introgressive hybridisation (introgression) (Anderson and Hubricht 1938, cited in Harrison and Larson 2014). The process of introgression works on a long term basis, and is thought to potentially be contributing to evolutionary processes, such as adaptive radiation and speciation (Grant et al. 2005). See more about Tropheus hybridisation of two majorly different phenotypes in Karlsson and Karlsson (2015).

Other cichlids featured (some only glancingly) in the video are: Callochromis cf. macrops, Eretmodus cyanostictus, Lamprologus callipterus, Lepidiolamprologus elongatus, Lobochilotes labiatus, Neolamprologus christyi, Neolamprologus modestus, Ophthalmotilapia boops, Ophthalmotilapia nasuta, Petrochromis ephippium, Petrochromis famula, Petrochromis sp. “Texas Blue Neon”, Simochromis diagramma, Telmatochromis brachygnathus and Variabilichromis moorii.

Video footage captured 2008.

Reference:

Anderson, E. and Hubricht, L. (1938) Hybridization in Tradescantia. III. The evidence for introgressive hybridization. American Journal of Botany, 25 (6): 396–402.

Harrison, R. G. and Larson, E. L. (2014) Hybridization, introgression, and the nature of species boundaries. Journal of Heredity, 105 (S1): 795–809; doi:10.1093/jhered/esu033

Karlsson, M. and Karlsson, M. (2015) A glimpse of the complexity of the genus Tropheus. Tanganika Magazyn, 17: 37–56.

Karlsson, M. and Karlsson, M. (2016) Tropheus cf. moorii “Red Namansi” and Tropheus sp. “Mtosi”. Tanganika Magazyn, 18: 106–128.

Grant, P. R., Grant, B. R. and Petren, K. (2005) Hybridization in the recent past. The American Naturalist, 166 (1): 56–67.

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Tropheus cf. moorii “Kala-Muzi” from Molwe

Molwe in southern Tanzania is home to many beautiful species of cichlids. One of them is a Tropheus which exhibits a greenish body colouration, together with a blue and reddish dorsal fin. These features are characteristics of a geographically wide variety, of which it is suggested to be a member. The varietal name “Kala-Muzi” indicates its geographical distribution, extending between Kala and Muzi along the southern Tanzanian shores of Lake Tanganyika. The abbreviation ‘cf.’ is short for the Latin term ‘conferre’, meaning ‘compare’, and is an indication of a provisional classification. This variety is considered a potential distinct species.

The picture shows a male individual of Tropheus cf. moorii “Kala-Muzi” in its rocky home at Molwe, about 6 km northwest of Muzi in Tanzania.

Read more about this Tropheus variety in Tanganika Magazyn no. 18. For order/enquiries please contact the editor, Dr. Marta Mierzeńska: biurokrakow@tropheus.com.pl
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Tanganika MAGAZYN no. 18 is available from the editor, Dr. Marta Mierzeńska: biurokrakow@tropheus.com.pl

The new issue of 132 pages is a special Tropheus issue, but it also contains two additional articles of different topics. In the opening article by a Zambian exporter, the author is looking back on the years as an ornamental fish exporter from Lake Tanganyika, sharing some of his anecdotes from the lake.

The different underwater habitats of Lake Tanganyika are overviewed in the informative article “Biotopes of Lake Tanganyika”, in which examples of cichlid species that these habitats accommodate, are given all through the article.

Featured are three interlinked articles about the genus Tropheus. Each article focuses on one out of six newly identified varieties in southern Tanzania. The issue contains 120 pictures of Tropheus, of which nearly all are captured underwater in, or at the shores of, Lake Tanganyika. Most of the pictures have never before been published. Included are several colour-drawings of Tropheus variants, so-called illustrative types. Associated topics discussed in the articles are the definition of a species, hybridisation, and conservation breeding.

All articles are in English.

For information and further inquiries concerning Tanganika MAGAZYN, please contact the editor on e-mail: biurokrakow@tropheus.com.pl
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Cichlids of Karilani Island, Lake Tanganyika, Tanzania (HD video footage).

Located roughly 1 km north of the border to the Mahale Mountains National Park (gazetted as national park in 1985), Karilani Island is a tiny uninhabited rocky island, surrounded by quite shallow water. The island is attached to the mainland by a submerged rocky ridge. In the water around the island, several beautiful cichlid species are found, of which some are featured in this video clip.

In the fish literature from the sixties and seventies, the island is often referred to as Bulu Island. Karilani Island is located in close proximity to Bulu Point (just over 600 metres to the north).

More about Mahale Mountains National Park (goo.gl/2u7RIe)

Video footage captured in 2007.

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Tanganika Magazyn new issue, soon available.

The new issue of Tanganika Magazyn (number 18) is a special issue on Tropheus. It contains three longer interconnected Tropheus articles stretching over almost 100 pages, with descriptions of three varieties (potential species) from southern Tanzania. Addressed in each article is a related topic, including species definition, hybridisation and conservation breeding. Tanganika Magazyn no. 18 contains lots of new information on the genus Tropheus, as well as a comprehensive article overviewing the different biotopes of Lake Tanganyika. The magazine consists of a total of 132 pages and is lavishly illustrated, with nearly 200 pictures from the natural habitat. All articles are in English.

The magazine is available from biurokrakow@tropheus.com.pl(please send your order or inquiries via e-mail).
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Ophthalmotilapia boops in DCG-Informationen

In the latest issue (May 2016) of DCG-Informationen (the journal of the German Cichlid Association), Wolfgang Staeck tackles the lesser known species Ophthalmotilapia boops. In a comprehensive article the author describes how he discovered the beautiful "Neon Stripe" variant in the Kipili Archipelago back in 1977. The article also includes a taxonomic history of the genus Ophthalmotilapia, and instructions on how to care for it in aquaria.

Based on our expeditions along the southern Tanzanian shores in 2008, where many new geographical colour variants of Ophthalmotilapia boops were discovered, the author presents the latest findings on the species, which includes, among other things, its exact distribution range. The article is accompanied by pictures of 40 different geographical variants, photographed in their natural habitat. This publication is the first to cover all geographical colour variants of Ophthalmotilapia boops.

http://www.dcg-online.de/vereinszeitschrift-05-2016/

A detailed map of the southern Tanzanian shores of Lake Tanganyika is available in Tanganika Magazyn no. 17 https://goo.gl/lccLso

Staeck, W. (2016) Ophthalmotilapia boops (Boulenger, 1901). DCG-Informationen, 47 (5): 106–116. Deutsche Cichliden-Gesellschaft e. V.
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Aulonocranus dewindti “Muzi, Polombwe Bay, Tanzania”

In pursuit of ichthyological discoveries and collections, De Windt was a young scientist who was accidentally drowned in Lake Tanganyika. He was attached to the Congo Free State Expedition, which was under the command of Lieutenant Lemaire. At Moliro in July–August 1898, the expedition obtained a small, but significant, collection of fishes, largely unknown to the scientific community by that time. Beautifully illustrated by Dardenne (the expedition’s artist) at the point of capture, one of the ten new species subsequently described by Boulenger (in 1899) was in memory of De Windt; it was named Paratilapia dewindti.

During the Tanganyika–Mweru Expedition in 1911–1913, the commander Stappers and his companion Dhont-De Bie obtained a large collection of fishes. A report on the fishes was in preparation by Boulenger when the First World War broke out. On his return to Europe, Stappers had joined the Medical Service of the Belgian Army; he died in 1916. His companion, Dhont-De Bie, now with the Belgian East African Expeditionary Force, supposedly stayed in the Belgian Congo until May 1919. During the end of that stay, he obtained a new collection of fishes (1210 specimens), mainly from around Albertville (presently Kalemie). Some of them were considered representing new species. One of these, which were described by Boulenger in 1919, was collected in the Lukuga River; it was named Paratilapia lukugae.

In an osteological study of the African Cichlidae (including those of Lake Tanganyika), Regan found in 1920 that Boulenger’s three largest genera (including Paratilapia) each contained species with significantly different skull characteristics. In order to give satisfactory and more precise definitions of the cichlids, and to express their natural relationships, several new genera had to be created. Allegedly not informed about Boulenger’s description of P. lukugae, Regan erected a monotypic genus, designated it Aulonocranus, and assigned P. dewindti as the sole member of it. Regan did not mention P. lukugae in his work. Obviously, Boulenger viewed the two species as distinct (i.e. separate individual diagnoses with dissimilar and rather distinct sketches), but in 1946 Poll synonymised them and, perhaps a bit hasty, commented that they only differ ‘by juvenile characteristics or numerical differences of negligible importance’. Nevertheless, in 2012 Kullander and Roberts reported on the existence of A. dewindti in the Lukuga River, 100 km downstream from the lake – a statement obviously being in favour of Poll’s synonymisation.

In developing a determination key of Lake Tanganyika cichlid genera, both Regan in 1920 and Poll in 1957 positioned Aulonocranus morphologically close to Trematocara (the latter yet another Lake Tanganyika genus), alluding to the possibility of a recent common ancestor. Both of the two genera possess the peculiar characteristics of enlarged pores and large channels with wide openings in the sensory system of the head, which enable the detection of prey that are invisible for the eye. However, following morphological analyses by several researchers, such as Greenwood in 1978, Liem in 1981, and Takahashi in 2003, Aulonocranus and Trematocara were not proven to be very closely related. Based on Greenwood’s study, Poll made in 1986 a natural arrangement of the cichlids of Lake Tanganyika, and classified them into 12 tribes. One of them was denominated Ectodini, to which Aulonocranus was assigned, and another Trematocarini, comprising Trematocara (and Telotrematocara, which in 2002 was regarded as a junior synonym to Trematocara by Takahashi).

The monophyly of Ectodini was supported by the DNA sequence data that was published by Sturmbauer and Meyer in 1993. In addition, in a molecular phylogenetic analysis by Koblmüller and co-workers in 2004, A. dewindti clustered nearest to Cunningtonia longiventralis (another ectodin species), which suggests a close phylogenetic relationship between the two species.

In 1995 Rossiter reported on an in situ study of A. dewindti where distinct ‘alternative reproductive tactics’ (‘art’) were evident. In addition to the normal male (normal territory owner), four phenotypically different males were present in an isolated population. They were described as: (1) female mimicry, (2) sneaking (interfering) behaviour, (3) satellite behaviour (males looking for a temporarily abandoned breeding nest), and (4) piracy (stealing breeding nest).

In a further field study, which included a species inventory of the Kalambo area (in southern Lake Tanganyika), Sturmbauer and co-workers reported in 2008 that A. dewindti was, next after Variabilichromis moorii, the most abundant species in the Kalambo area, with about 40 individuals per 100 m2. They also found that A. dewindti defended the largest total territorial area, which was around 5.0 m2.

Read more about V. moorii and ‘art’ in a blog article here: http://goo.gl/ipyw6U

A. dewindti is a eurytopic and ubiquitous species. Throughout the lake it is found in a variety of biotopes, normally the shallow sediment rich biotope consisting of sand and small rocks, often in combination with plants. Besides the reported existence in Lukuga River, A. dewindti has also been found in Rusisi River (in the northern part of the lake). According to Poll in 1956, A. dewindti is a carnivore species and its diet comprises larvae of insects, such as Diptera (true flies) and Plecoptera (stoneflies), as well as a variety of shrimps.

There is not very much geographical colour variation in A. dewindti. The body-colour pattern may alter in terms of more or less yellow (and orange) versus blue. However, over the years we have found a few extraordinary variants. For example, in 2007 we found and documented (by film and photo) a silvery bright-blue individual variant at Karilani Island (central part of the lake). This peculiar specimen was devoid of yellow and orange; instead, it possessed a colouration of bright blue with an irregular pattern of silvery stripes and spots. Moreover, in 2002 we found in Cape Mpimbwe area a variant, which displayed a striking colouration. Instead of the bluish stripes and spots on the flank of the body, this variant had bright orange stripes and spots on the yellow flank. It was named ‘King Orange’. Moreover, a picture of a colourful variant of A. dewindti in its natural habitat at Kitawe (about 9.0 km northwest of Muzi) will be published in Tanganika Magazyn​ no 18.

Footage captured in 2008.

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Neolamprologus buescheri

In August 1982 Heinz Büscher discovered a new fish at 18 metres depth at Cape Kashese in the Zambian part of Lake Tanganyika. The following year it was described as Lamprologus buescheri by Wolfgang Staeck.

In Tanzania the species is found from Kalala Island in Kala Bay south to the border with Zambia. This distribution range was established by us in 2008.

The picture shows a male individual of Neolamprologus buescheri at 40 metres depth in Polombwe Bay just off Muzi village. In this rocky habitat the species is quite common at depths greater than 40 metres.

Reference:

Büscher, H. H. (1992) Verbreitung und Ökologie von Neolamprologus buescheri. DATZ, 45 (5): 305–310.

Staeck, W. (1983) Lamprologus buescheri n. sp. from the Zambian part of Lake Tanganyika (Pisces: Cichlidae). Senckenbergiana Biologica, 63 (5/6): 325–328.
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