Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1, 89-121 30. 04. 2004
Evaluating limnic diversity: Toward a revision of the unionid bivalve Coelatura Conrad, 1853 in the Great Lakes of East Africa and adjacent drainage systems (Mollusca, Bivalvia, Unionidae)
Henning Scholz1 & Matthias Glaubrecht2
With 9 text-figures, 5 plates, and 8 tables
Abstract
This paper evaluates the status of type material of the unionid bivalve Coelatura Conrad, 1853, with special emphasis on valuable historical material housed in the Malacological Collection of the Berlin Natural History Museum (ZMB), including collections done by the eminent explorers Emin Pascha, Franz Stuhlmann and Richard Bohm. It aims to provide the basis for judging the species diversity and the degree of endemism in these limnic bivalves inhabiting lacustrine and fluviatile habitats in the East African Rift System and adjacent drainage systems. In an early comprehensive account, Eduard von Martens in 1897 compiled about 40 species, subspecies and varieties of Coelatura from the region. Most recently, this number was redu ced to 14 accepted species. Here, from a total of 25 named taxa, the material of 14 primary types from the ZMB collection is described and figured, including syntypes of three infraspecific taxa and eight lectotype designations, as an initial step toward a systematic revision of the genus. Tliis is supplemented by comparisons with six primary types from the Brisith Museum of Natural History, London (BMNH) and National Museum of Natural History, Washington (USNM) collections, respectively, which are also figured. Of the 11 specific taxa originally described by Martens, only three are recognized herein as valid species, viz. C. mossambicensis, C. hypsiprymna and C. stuhlmanni, whereas the remaining eight of his names are synonymised with the currently accepted valid Coelatura species of East Africa. Apart from two ubiquitous species, C. mossambicensis and C. ratidota, that are widely distributed throughout the East African drainage systems, all other congeneric species are endemic to their respective lacustrine environments, with the majority of the 14 Coelatura species under study occurring in only one of the major East African lakes. It is noted that the number of species per lake shows a nearly equal distribution that can only roughly be correlated with lake size, but not with the extremely different lacustrine settings, geology and hydrology, for example, in Lake Tanganyika (three endemic species) and Lake Malawi (two endemic species) versus Lake Victoria (four species). In conclusion, we find that apparently the maximum number of endemic Coelatura species capable of living sympa- trically in East African lakes is between two and four, and therefore does not vary with a numerical magnitude or taxonomic composition and diversity comparable, for example, to gastropods and in particular to cichlids in these lakes.
Key words: Unionid bivalves, Coelatura, types, East African Rift System, endemisms, history of collection, Carl Eduard von Martens, Emin Pascha, Franz Stuhlmann, Friedrich Fiilleborn, Hermann Schubotz, Richard Bohm
Introduction Although the first animals to attract the atten tion of naturalists to these lakes following the The Great Lakes of the East African Rift Sys discovery, for example, of Lake Tanganyika in tem provide natural laboratories for evolutionary 1858 and thus, providing another trigger for the studies. In particular the fish faunas of the three first British and French research expeditions in largest lakes, viz. Lake Victoria, Lake Tanganyi East Africa, the molluscs in these lakes are by ka, and Lake Malawi, are extremely diverse and far not as diverse as the fish faunas. Never are currently subject to detailed investigations theless, in particular the two rift lakes Tanga looking into the origin of biodiversity, since nyika and Malawi hold a spectacular array of several hundreds of species of cichlids have many diverse endemic gastropod species (for an evolved separately in each of these lakes (e.g. introduction, overview and discussion see e.g. Coulter 1991, Lowe-McConnell 1993, Snoeks Coulter 1991, Glaubrecht 1994, 1996, 2003b, 2000, for a most recent study see e.g. Verheyen Michel 1994, West & Michel 2000). While the et al. 2003). main focus of students working on molluscs of
1 Institute of Palaeontology, Museum fur Naturkunde, Humboldt University, InvalidenstraBe 43, D-10115 Berlin, Germany. E-mail: [email protected] 2 Department of Malacology, Institute of Systematic Zoology, Museum fur Naturkunde, Humboldt University, Invaliden straBe 43, D-10115 Berlin, Germany. E-mail: [email protected] Received 11 March 2003, accepted 14 October 2003 90 Scholz, H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853
East Africa has been gastropods, perhaps due to cations of relevant taxa, and followed by a jud their higher morphological disparity and taxono- gement of the systematic position and zoogeo mical diversity, the bivalves were only rarely the graphy of the bivalve taxa involved. In addition, central focus of studies that, in general, go sel next to a few types from BMNH and USNM, dom beyond the documentation of “species” type material in the Senckenberg Museum in richness treated from a traditional, i.e. typologi Frankfurt (SMF) is considered that was also cal, point of view. ignored by Daget (1998). The first comprehensive taxonomic study of the unionoids of the East African Great Lakes has been carried out by Carl Eduard von Mar General remark on the origin and history tens (1897). Martens (1831—1904) was curator of remarks of Coelatura collections invertebrates, in particular molluscs, at the Nat ural History Museum in Berlin from 1855 until Not only the work of systematists using historical his death. During that time he was responsible collections but also the increasing interest in the for establishing one of the largest and richest historical component of natural history collec collections in this field, to which later only Jo tions, for instance as reflected by the widely ac hannes Thiele (following Martens as curator in claimed “Voyages o f discovery” exhibition of The 1904) added in a comparable manner; for a brief Natural History Museum (BMNH) in London synopsis of Martens’ life and work see the com (see e.g. Rice 1999, Ackery 2002) or the “Thea- pilation in Kabat & Boss (1997). trum Naturae” exhibition of the Humboldt Following Martens, it was Fritz Haas (1936) University in Berlin (see e.g. Bredekamp et al. presenting the second extensive study of the un 2000), demand the recovery of original and ionoids of East Africa. This study was mainly authentic material. Even more, historical biogeo based on material collected between 1931 and graphy is reliant upon accurate locality data. 1932 during the Hans Schomburgk Expedition in However, historical museum collections pose Africa (Zilch 1967). Later it was in particular numerous, albeit not insurmountable, difficulties Mandahl-Barth who contributed to the knowl with old labels referring to long forgotten and/or edge on the bivalve faunas of East Africa (see older locality names and collectors. Unfortu Mandahl-Barth 1954, 1972, 1988, Brown & Man nately, many of the localities given on the origi dahl-Barth 1987). Other important studies deal nal labels and/or the literature cause problems of ing with bivalves of the Great Lakes of the East interpretation. Apart from difficulties with the African Rift System are by Leloup (1950), Crow transliteration that are overcome by carefully ley et al. (1964), Appleton (1979), and Kondo comparing cited localities from the author’s origi (1984, 1990). nal descriptions with label information and col However, given the lack of a modern systema lectors narratives (sometimes accompanied by tic revision, the exact biological diversity of Coe maps or at least simple sketches of the regions latura species in Africa long remained unknown. explored) where ever available, questions often While Haas (1936) listed 48 congeneric species remain with obscure localities associated in par and subspecies (n = 47 in Haas 1969), other ticular with African collections (see below). In works, such as e.g. Modell (1942, 1949) have the quest for the verification of these, next criticised the “species making” in particular in to (auto-)biographical accounts, we carefully unionid bivalves. However, only much later checked other available and useful documenta Mandahl-Barth (1988) restricted the species tion as exemplified below. number in Coelatura to 28 species and subspe For example, the labelled material in the ZMB cies. Most recently, Daget (1998) has presented for some Coelatura taxa, e.g. C. hauttecoeuri (see an up-to-date list of the African bivalves with there), carry the name “Emin Effendi” as collec very few annotations, accepting 34 species and tor. However, “effendi” (also written “efendi”) subspecies of Coelatura to occur in rivers and stems from the Turkish word for “Sir” and repre lakes in Africa. Apparently, Daget (1998) was sents a honorary title for higher state officials, as unaware of type material housed in the Museum does the more often used Turkish title “Pascha” of Natural History of Berlin. (= pasha) occassionally added to the name of Therefore, one main aim of the present study higher and most respected Turkish state officials. is to document and evaluate the type material in Both the names Emin Pascha and Emin Effendi the ZMB in combination with the clarification of found on many labels in the ZMB collection, the geographic occurence based on the type lo thus, refer to the same collector, viz. Eduard Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 91
Carl Oscar Theodor Schnitzer, born 28 March The importance of Emin Pascha’s collecting lies 1840 at Oppeln, in the Prussian province of Sile primarily with providing the material, given to the sia, and murdered in Kanena (or Kinene; today Berlin Natural History Museum apparently by Congo) on October 23, 1892. Known as Emin Stuhlmann (see below), on which Eduard von Pascha, he is among the eminent and important Martens’ description of Coelatura taxa rested. pioneers of African exploration. This also includes the extension of the known Following his studies of medicine in Breslau, range of these taxa. Linking information on col Konigsberg and Berlin, Schnitzer left Germany lectors with the region explored, that way some entering Turkish services in 1865 in Albania otherwise obscure localities could be verified where he worked mostly in Antivari as surgeon. from the mentioned associated documentation. Since 1871 he served in the personal entourage Crucial in this endeavour was the material (retinue) of the Turkish gouvernor Ismail Hakki collected for and given to the Berlin Natural Pasha in Konstantinopel visiting many regions of History Museum by the African explorer and the Turkish area of political influence, which then zoologist Franz Ludwig Stuhlmann (1863—1928). included Northern Africa and Arabia. He was He traveled across East Africa first from 1888 to not only an administrator and philanthropist 1890, resulting in zoological studies published la working in Turkish and later, since 1875, in Egyp ter by Karl Kraepelin (as editor) in “Zoologische tian medical services, but a much respected col Ergebnisse einer in den Jahren 1888—1890 ... in lector, primarily of birds, mammals and insects, die Kustengebiete von Ostafrika unternommenen traveling areas highly remote even today, such as Reise”. In 1890 Franz Stuhlmann joined the Ger the Egyptian Sudan and its Equatorial Provinces man Schutztruppe and accompanied Emin Pascha at the Upper Nile. Schnitzer adopted the name as scientific assistant on his expedition to Lake “Dr. Emin Effendi” from his predecessor working Victoria. He not only reported about these ex as surgeon in this region from 1876 on. In 1879 plorations in his account “Mit Emin Pascha ins he was appointed governor of the Equatorial Herz von Afrika" (Stuhlmann 1894), but later Provinces, from then on called with the honorary also edited Pasha’s diary (Stuhlmann 1917— 1927). title “Bey” (see Vajda 1959). From 1893 to 1905 Stuhlmann served as official At the time of traveling, partly with Gaetano in several functions for the government of Casati and Wilhelm Junker, and making collec Deutsch-Ostafrika, the colony of German East tions in the 1880s and early 1890s, Emin Pascha Africa. (a title awarded around 1888) was still governor In 1905 Stuhlmann became director of the Bio- of the southern Sudanese province of Equatoria, logisch-Landwirtschaftliche Institut at Amani in and was eventually to represent the final vestige Tanzania, a region also called Usambara be of Egyptian control of the Sudan in the face of tween Arusha and Tanga, founded in 1902 and the Mahdist incursions since 1881 (summarised later to be continued as the Agricultural Re from Ackery 2002), eventually leading to the search Station of the British colony (see Bald & “rescue” and relief expedition by Henry Morton Bald 1972; Nowell 1933). This is relevant for the Stanley in 1886—1890, that was much respected verification of another locality associated, for ex in contemporary literature (see e.g. Stanley 1890, ample, with material assigned herein to C. haut- Casati 1891, Smith 1972). After returning from tecoeuri and C. monceti that both occur, presum the lost Egyptian provinces and finally reaching ably endemic, in Lake Victoria only. Although the coast in December 1889 at the German sta “Amani” is indicated on the labels of a collection tion in Bagamoyo, Emin Pascha entered German made by the German entomologist Julius Vos- services in 1890. In the same year he was leading seler who, between 1903 and 1908, worked in a German Expedition to inner Africa, accompa Amani, it seems more likely that these collec nied by Franz Stuhlmann (see below) and Haupt- tions were made on the occassion of frequent man Langheld, to found a station (Bukoba) at explorations in East Africa (as e.g. described by the western shore of Lake Victoria. Following Braun 1931) and only subsequently stored in or several fights with native people, severely ill and sent out via Amani, instead of assuming the sta blind, Emin Pascha sent Stuhlmann back to the tion itself to be the original site of collecting. East African coast while he tried starting in Material was also collected by the physician March 1892 to reach the western coast, but was Dr. med. et phil., Dr. rer. nat. h.c. Friedrich murdered on the way. His diaries, containing rich Fulleborn (1866—1933), who served as military scientific materials, were found and secured in surgeon between 1896 and 1900 with the Ger 1893 by the Belgian Captain Dhanis. man colonial forces in East Africa, and who was 92 Scholz, H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853 also advised to conduct scientific studies. He ac of Dr. Richard Bohm (1854—1884) who, accom companied expeditions to the northern Nyassa panied by his friend Paul Reichard, explored not region, i.e. the shores of Lake Malawi in today only the eastern shore of Lake Tanganyika in SW Tanzania. Special mention here deserve 1881 and 1883 at Karema, but who also crossed localities such as “Wiedhafen” (today Manda) at the lake calling in August 1883 in Qua-Mpala at the eastern shore and a German station named the western shore. From there the two naturalists “Langenburg” at the estuary of the Lumbira started as first European explorers on a journey creek, where Fiilleborn was stationed from 1898 into the then completely unknown western re to 1900. From there he explored, financially sup gions of Tanganyika. After having found and ported by the Royal Academy of Sciences in explored the source areas of the Congo system Berlin, the region between Lake Rukwa in the at the Lualaba River and its tributary Lufira, in north and the Shire and Zambezi River south of the southern Urua area, and having discovered Lake Malawi. According to his own report Lake Upemba, Bohm died from fever there in (Fiilleborn 1900), he collected about 800 birds March 1884 with only Reichard returning to the (with 18 new amphibians species) next to numer coast. For a more detailed summary of this expe ous mammals, over a thousand fishes, amphibs dition and the scientific, and in particular zoolo and reptiles, as well as many thousand insects gical, achievements of Bohm and Reichard see and other invertebrates, including zooplankton e.g. Schalow (1888). Through the courtesy of the of Lake Malawi, thus providing the basis for the latter the Berlin Museum also received, next to description of many new species. From 1901 on, birds and mammals, valuable Coelatura material Fiilleborn was working for the Institute of Tropi for two species, viz. C. burtoni and C. horei cal Diseases in Hamburg (being appointed as (= Unio bohmi (Martens 1897)). However, most director following Bernhard Nocht in 1930) and shells are either labeled with imprecise locality as administer in Hamburg helping with the foun from “Lake Tanganyika” or give “Karema” at dation of the university there in 1919, where he the eastern shore only, while any indication for lectured since then as professor for tropical med collections done in the still largely unexplored icine (see Olpp 1932). western Tanganyikan area is lacking. Finally, some of the additional Coelatura Following this “golden era” of naturalists’ ex material was collected by the German zoologist ploration in Africa at the turn to the 20th cen Johann G. Hermann Schubotz (1881—1955), who tury, the malacological collection of the ZMB was scientific assistant and later professor (since since then only rarely has gained additional and 1916) at the university in Berlin. In 1907—1908 new material from the regions in question. It is and again in 1910—1911 he accompanied Ger only now that this long neglected tradition is man scientific expeditions led by Herzog Adolf continued, essentially with focus on ethanol pre Friedrich von Mecklenburg in East Africa that served soft-body material of unionid bivalves explored the region between Lakes Victoria, and other limnic molluscs. Kivu, Edward, and Albert as well as the Ituri and Aruwimi Rivers to the west (see Schubotz 1909). Schubotz, who also edited the zoological Material and Methods parts, particularly the observations on mammalia and aves, of Emin Pascha’s diary from the years This study is essentially based on material including hitherto undetected types housed in the Museum of Natural History 1879—1888 [see Introduction in Schubotz, 1921; of Berlin (ZMB). About 120 lots in the ZMB were evalu published as volume VI of Stuhlmann (1917— ated. In addition, the collection of the Senckenberg Museum 1925)], provided rich zoological collections to the of Frankfurt (SMF) and parts of the collections of Paris (MNHN), Tervuren (MRAC), and London (BMNH) were museums in Berlin, Hamburg and Frankfurt am studied by the first author. While the types in the ZMB sur Main. vived the bombing of the museum in 1944—1945 (for a gen In addition many other early German ex eral account see e.g. Friedrich 2002) and the subsequent dec ades-long post-war period, it should be noted for material in plorers — for example, Rudolf Grauer-Troppau, the SMF, though, that some of the unionoid bivalve types Glauning or Richard Bdhm and Paul Reichard, mentioned as extant in Frankfurt were actually lost in World to mention only a few of the most reknown — War II. According to Zilch (1967) many unionoids were then stored in a building in the vicinity of the Vogelsberg to pre added valuable material from their expeditions vent destruction. Unfortunately, just this storage was the only to the East African rift region, including particu one out of 50 others that was completely destroyed in the larly the area at the western shore of Lake Tan last days of the war. In addition to the types, recent collections were considered ganyika. Special emphasis should be made in this for comparison. In 2000 a field trip was carried out by the context to the unfortunate four-year expedition first author (then at the Univ. Wurzburg) to study the union- Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 93
Fas! African drainage system: CONGO m Coelatura mossambicensis ^ Coelatura ratutota Lake Albert Kasenvc KF.NYA Mhert-Fdward lake system: A Coelatura acuminata UGANDA O Coelatura hakeri Bay E Coelatura stuhlmanni Jcfin-sj iowe-Uland Kissakkj Kisumu* Fake Victoria: Katcrcngiy / Lake * Coelatura alluaudi Kiruwekiruwe |q / hdward ft Coelatura cridlandi V i is hum hi Towalio # □ Coelatura hauttecoeuri V ictoria Kwa K issero • Coelatura monceii Hukoba m • Kwaza iM kiegs RrtTt i Fake Tanganyika: RWANDA A Coelatura burtoni Masan/a Nvumircinbci (Inn Iwai ♦ Coelatura horei liusisi is Coelatura ujijiensLi
Fake Malawi: A Bujumbura O Coelatura hypsipnmna ■ Coelatura nyassacnsi.x
100km AKigoma j ^ Rusago
AlbcrtvillcJ \ A A Kawimla INDIAN
Oar cs Salaam l Karcma TANZANIA OCEAN Tanganyika \ A Kirando i \ Lake
f . A Kasanga Ulanga
O l-akc Kisiwa Mwaya ■ ■ Lumbira Kambwc H
■i Manda
ZAMBIA Mbamba Bav
Kande Beach ■ -.Ftake ( ! Malawi
MALAWI
Lilongwe Nanchcngwa Lodge Palm Beacn ' Mangochi Malombt MOZAMBIQUE Zambezi Rive
ZIMBABWE
Fig. 1. The distribution of unionid bivalves of the genus Coelatura in the Great Lakes and adjacent drainages of the East African Rift System, based on data presented in the text. Note that C. cridlandi (Mandahl-Barth 1954), occuring in Lake Victoria, is omitted here due to lack of material in the Museum of Natural History Berlin. 94 Scholz, H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853 oid bivalves of Lake Malawi. More than 1,700 shells of Coe latura were collected from 26 localities along the western shore of the lake (Scholz 2003). The PlW-numbers of these shells (referring to the collection in the Palaeontological In stitute of the Univ. Wurzburg) are given here for future com parison. T he study area In this study only unionid bivalves from the Great Lakes of the East African Rift System and the adjacent drainage sys tem are evaluated. The following compilation is arranged accordingly, introduced by a brief characterisation of the respective limnic setting. Subsequently, some of the bio- geographical implications are briefly outlined in the Discus sion. Despite the connection of Lake Albert with the Nile River, the bivalves from this drainage are omitted here because of their wide distribution in the face of lacking comparative ma terial, corresponding to the procedure of Martens (1897). However, in contrast to the latter who arranged the species according to possible relationships, they are arranged herein according to their occurence from north to south in the East African Rift System. It starts with the bivalves from the river systems and continues with those from Lake Albert, Lake Edward, Lake Victoria, Lake Tanganyika, and Lake Malawi. For each species the distributional area as indicated by the information from the studied collections is shown in Fig. 1. Although specimens of Coelatura cridlandi (Mandahl-Barth Fig. 2. Two shell outlines of left valve of Coelatura illustrat 1954) from Lake Victoria are not present in the collection of ing the shell parameters measured for this study; note that the Museum of Natural History of Berlin, this species has the height is always measured to the dorsal margin of the been added for comparison in the map and Appendix. shell, not to the umbo. General information about the lakes are taken from the Worlds Lake Database (http://www.ilec.or.jp/database/data- base.html). The geographic position and the current name of shell (Fig. 2). It has to be mentioned particularly that the the localities used on the distribution map of Fig. 1 are taken height of the shell was also measured between the dorsal from several sources: in addition to standard atlas and Win margin and the ventral margin when the umbo rises above dows Encarta, we used http://www.calle.com/world/. As out the dorsal margin dorsally, as indicated on Fig. 2 lined above, some localities were problematic in verifying geographic position and current name, and are discussed in detail under the relevant species in the systematic part. Museum acronyms Taxa and taxonomy BMNH — The British Museum (Natural History), The list of synonyms of each of the studied species contains the original description of the species and the taxa of Mar London tens (1897) which have to be synonymised. Further syno HLMD — Hessisches Landesmuseum, Darmstadt nyms are given by Daget (1998). The only exception is Coe MNHN — Museum National d’Histoire Naturelle, latura nyassaensis with a few other synonyms based on the results of Scholz (2003). Paris Variety names for Coelatura species given by Martens are MRAC — Musee Royal PAfrique Central, Ter- listed under the valid and accepted species. This relates to vuren var. sturanyi (of burtoni), var. minor (of lechaptoisi, which is considered synonym of C. mossambicensis) and var. brevior PIW — Institute of Palaeontology, University (of rostralis, which is a synonym of C. burtoni). Although Wurzburg regarded here as of the least biological importance of all SMF — Senckenberg Museum, Frankfurt taxa studied, in the ZMB collection, the respective lots are labelled and marked according to Martens’ original treat USNM — National Museum of Natural History, ment as name-bearing variety. Smithsonian Institution, Washington In order to fullfill the requirements of article 74 of the ZMB — Museum of Natural History, Humboldt International Code of Zoological Nomenclature (fourth edi tion), i.e. to include a statement of taxonomic purpose, the University Berlin (formerly Zoological lectotype designations proposed herein are to be understood Museum Berlin) as being done to ensure the name’s proper and consistent application. For this purpose, i.e. to fix the status of the spe cimen as the sole name-bearing type of a nominal taxon. the statement of lectotypes is herein explicitly made and re A — On the systematics of the genus Coelatura peated for each single case, as any abbreviated version or Conrad, 1853 procedure is currently not considered sufficient (Kraus, pers. comm. April 2002), despite contradicting opinion (see e.g. Pulawski & Kerzhner 2001). Class Bivalvia Linne, 1758 Subclass Heteroconchia Hertwig, 1895 Biometry Superorder Palaeoheterodonta Newell, 1965 For each of the studied species some important parameters Order Unionoida Stoliczka, 1871 were measured to the nearest 0.5 mm: length of the shell, Superfamily Unionoidea Fleming, 1828 height of the shell, and length of the posterior part of the Family Unionidae Fleming, 1828 Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 95
Systematic remark: Note that the systema- Coelatura Martens, 1880, Caelatura Germain, tics and classification of Bivalvia, suffering long 1921 and Ariocaelatura Germain, 1921 are objec from discussions and analyses being based essen tive synonyms of Plegma Gude, 1911, a genus of tially on single character systems only, is to date helixarionid gastropods. Rosenberg et al. (1990) still unresolved on various taxonomic levels; for intensively looked into this particular nomencla- a general overview and the most recent phyloge torial problem and the confusion resulting from netic analyses see e.g. Giribet & Wheeler (2002) the diphthongs “ae” and “oe” when printed as and various accounts in Harper et al. (2000). ligatures, identifying Coelatura as the correct and This situation also holds true for unionids or valid spelling of Conrad’s (1853) generic name “Najaden”, as the naiades (or pearly freshwater for the bivalves of the family-group name Coela mussels) have long been called in German litera turinae Modell, 1942. Note that many studies ture. In addition, the phylogenetic position and and accounts long employed the erroneous spel familial placement of Coelatura was also long un ling (e.g. Haas 1936, 1969, Modell 1942, 1949, certain. While Modell (1942: 190; 1949: 46) as Van Damme 1984). signed them to the Coelaturinae, Haas (1969) A comprehensive list of synonyms has been placed the genus in the Unioninae Fleming, presented by Daget (1998). Since some confu 1828. Hoeh et al. (2001) discussed the most re sion exist, in the literature as to the nature and cent phylogenetic data available for the Unionoi- delimitation of the genus, a few comments will da in more detail, placing Coelatura (with its follow here concerning our understanding of the type species aegyptiacus Cailliaud, 1827) in the taxonomy. For a long time two genera domi family Unionidae. As revealed by their com nated the Unionoida: Unio and Anodonta. Most bined analyses of morphology and COI data, of the unionoids with teeth were classified as however, this grouping turned out to be para- Unio and those without teeth as Anodonta. With phyletic, with Coelatura being most distinct from changing perception during the 19th century other unionids. Apparently, this genus represents several workers began to assign the numerous one of the two lineages resulting from the ear unionoid species into several genera. One exam liest cladogenic event in limnic bivalves ancestral ple is the study of Conrad (1853) who erected to African, Eurasian, and North American un- for African unionids several new genera and ionoideans, contradicting the long perceived an subgenera of Unio, thus establishing also the cestral nature of the Margaritiferidae. genus Coelatura. However, this procedure was not commonly followed. For example, Martens (1897) ignored Conrad’s (1853) approach and Coelatura Conrad, 1853 continued to classify all unionids investigated from the recent collections made in Africa with Coelatura Conrad, 1853: 268 (Type species, by monotypy: in Unio. Nevertheless, during subsequent dec Unio aegyptiacus Cailliaud, 1827) Nitia Pallary, 1924: 43 (Type species: Unio teretiusculus Phi ades, the perception of Conrad (1853) found lippi, 1847) more general application in the relevant litera Nyassunio Haas, 1936: 85 (Type species: Unio nyassaensis ture. Lea, 1864) Grandidieria Bourguignat, 1885: 4 (Type species: Unio bur- In addition to Coelatura, over the last century toni Woodward, 1859, by subsequent designation of Simp several other genera of unionids have been ap son 1900) plied to African unionids. Nodularia Conrad, History, taxonomy, and systematic 1853, Parreysia Conrad, 1853, and Indonaia placement: Following the emendation to Cae- Prashad, 1918 were originally erected for Asiatic latura by Simpson (1900), for a long time confu unionids (Conrad 1853, Haas 1969), but later sion existed about the genus name Coelatura for also adopted for African species (e.g. Haas 1936, unionid bivalves. This confusion followed from a Pilsbry & Bequaert 1927). However, Haas (1936) mistake in Conrad’s (1853) original publication, already discussed problems related to attributing where he, on page 267, used the spelling Ccela- generic names of Asian taxa to African unionid tura (i.e. Caelatura) for his new subgenus in a bivalves and consequently refused to use Indo table, but employed the spelling Ccelatura (i.e. naia later (Haas 1962, 1969). Modell (1949: 43) Coelatura) on page 268 when designating the clearly separated Parreysia from Coelatura and subgenus. However, to complicate the matter, restricted the former to Asian unionids; see also Caelatura Conrad, 1865 is the valid name for the Modell (1942: 185—187) who employed charac genus of barleeid gastropods renamed Actaeone- ters of the reproductive anatomy for his system- ma Conrad, 1865, while Coelatura Pfeiffer, 1877, atisation. However, due to high conchological 96 Scholz, H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853 variability of the shells of Coelatura and similari productive strategy of African unionids is avail ties between Coelatura and Parreysia, Indonaia, able. Therefore, it appears to be appropriate for and Nodularia, it is difficult — based on conchol- the time being to synonymise Grandidieria with ogy only — to actually differentiate unequivo Coelatura. This procedure takes into account cally between these taxa. Therefore, following Haas’ (1936) view which conceived Grandidieria Mandahl-Barth (1954) it appears to be more ap as the lacustrine variation of Coelatura in Lake propriate to conceive all African bivalves of Tanganyika. We interprete this as further indica these mentioned taxa within the genus Coela tion of ecophenotypical change in African union tura. In this context it should be mentioned that id bivalves, i.e. anticipating that changes in shell cladistic analyses allowing to objectively judge morphology from fluviatile individuals to lacus on the phylogenetic relationships of Coelatura trine individuals are related to the ecological are still in their infancy. Kat (1986) and Bogan & differences between both environments, as has Hoeh (2000) discussed an Indian origin of Coela been suggested in general for unionids e.g. by tura, and it was proposed that Pseudomulleria Modell (1942, 1949). dalyi, a cemented unionoid bivalve, is the near In conclusion, the known conchological varia est relative of Coelatura aegyptiaca (Cailliaud, bility not only renders the distinction of separate 1827) (cf. Bogan & Hoeh 2000), but a com genera problematic, but also of some named spe prehensive modem phylogeny of these Oriental- cies (and in particular several named varieties) Ethiopian unionids is lacking to date; see discus that might only represent lacustrine morpho- sion in Hoeh et al. (2001) who perceived Coela types. tura as representative of one of the most ancient cladogenetic events in Africa. Thus, we here con Morphological observations: Generally sider Coelatura to represent the only genus of the shells are of medium thickness and medium unionid bivalves with an occurrence solely on size. Only the shells of a few species grow larger the African continent. than 50 mm. The umbonal zig-zag sculpture, typi With Nitia Pallary (1924) erected another new cal for all unionids, may cover the whole shell in genus for all elongate and lancet-shaped African Coelatura. Individuals of Coelatura are charac unionids possessing nearly straight and parallel terised by palaeoheterodont dentition. However, ventral and dorsal margins. However, also true with changing shell morphology the morphology representatives of Coelatura with a very similar of the teeth is also changing. This is particularly shell morphology are known (Mandahl-Barth true for the pseudocardinal teeth: Thick and tri 1988). Haas (1936) erected the genus Nyassunio angular shells show generally no distinct pseudo for the lacustrine species of Lake Malawi and cardinal teeth. The teeth are more or less inten Lake Tanganyika, but failed to give sufficiently sively slashed. In contrast, the pseudocardinal distinct characters to separate this genus clearly teeth of thin-shelled and elongate individuals are from Coelatura. The same is true for the genus also thin and elongate. The lateral teeth are Afronaia, which was introduced by Haas (1962) more consistent in shape. They are long and thin to replace the Asiatic generic name Indonaia in elongate specimens and relatively short and (see above). Consequently, it seems to be more somewhat thicker in short and thick-shelled spe appropriate to synonymise Nitia, Nyassunio and cimens. Afronaia with Coelatura, as is done within the The morphology of the soft parts of all species present paper. Nevertheless, it should be men referred here to as Coelatura is very similar tioned that Daget (1998) considered Nitia and according to Mandahl-Barth (1972), lending Nyassunio as distinct genera, albeit without giv further support to the claim for synonymisation ing any further reason for this. of all other named African unioinid (sub-)genera Even more problematic is the synonymisation mentioned above. of Grandidieria. The type species of this genus, Distribution: The genus as conceived of here Coelatura burtoni, is characterised by some dis is restricted to the African continent where it tinct shell characters (see under this species). In occurs with a total of about 30 species (see In addition, the reproductive behaviour of this troduction and Biogeography section under Dis bivalve is also special because, in contrast to the cussion for accounts on the number of species majority of other unionoids, C. burtoni has direct and their distribution). development without a parasitic larval stage (Kondo 1990). However, apart from this study Remarks: The shell morphology of the species on C. burtoni no other investigation on the re discussed herein is strongly related to the en Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 97 vironment. High energetic habitats in rivers or in shells difficult. African rivers are known to be the shore region of the lakes are characterised interconnected in times of extreme rainfall with by elongate shells, for example, whereas in off frequent flood plains serving as zones of transi shore habitats of the Great Lakes a triangular tion that allow frequent faunal exchange. At the shell morphology is common (Scholz 2003). This same time these plains prevent effective geogra strong relation between shell morphology and phical separation and, thus, allopatric speciation environment is responsible for the high morpho of populations (as most commonly assumed spe logical variability of the shells within species and ciation modus) in isolated drainage systems. For the similarities of the shells of different species example, Beadle (1981) indicated that bivalves in similar habitats. of Lake Malawi originated in the Upper Zam bezi River due to earlier temporal connections (see below for more detailed discussion). B — Systematic part with taxa arranged is to their occurrences Coelatura mossambicensis (Martens, 1860) East African drainage system Plate 1: 1-6 The Coelatura species from the Nile River and Unio mossambicensis Martens, 1860: 218, pi. 3, figs 3—5. its tributaries are not included here, although Unio liederi Martens, 1897: 226, pi. 7: 19. Lectotype, here de signated in order to ensure the name’s proper and con this river, of course, has manyfold relations to sistent application (ZMB 104.813, leg. Lieder; 1 articulated the lakes of the East African Rift System on specimen; Plate 1: 3); type locality: “Ulanga im oberen which we focus. For example, the Luvironza Rufidschi-Gebiet”; Tanzania: Ulanga, Ruaha River (8°10'S 36°55'E). One paralectotype (ZMB 104.814, leg. Lieder; River in Burundi, as the major affluent of Lake 1 left valve; Plate 1: 4) and another paralectotype (SMF Victoria (via the Kagera River), is the source of 9.670, leg. Lieder; 1 articulated specimen; figured in Haas the Nile River. Before becoming the White Nile, 1936: pi. 4: 4b; vidi) from Tanzania: Mbamba Bay, Lake Malawi (11°16'S 34°46'E). the waters of Lake Victoria and the Victoria Nile (with a length of 420 km) Lake Albert, Type material: Lectotype, here designated in order to en sure the name’s proper and consistent application (ZMB which is connected to Lake Edward via the Sem- 4.654a, leg. Peters; 1 articulated specimen; Plate 1: 1). Para- liki River; see Fig. 1. Near Khartoum in Sudan lectotypes (ZMB 4.654b, leg. Peters; 3 articulated specimens, the White Nile and the Blue Nile from the high 2 left valves, 1 right valve; Plate 1: 2); (SMF 3.547, leg. Peters; 5 articulated specimens; figured in Haas 1936: pi. 4, lands of Ethiopia the Nile River. figs 3a—b; vidi). However, the bivalves of the Nile River are not restricted to this river only. Coelatura aegyp- Type locality: “Tette”; Mozambique: Tete, tiaca, for example, is also known from Chad, lower Zambezi (16°10'S 33°36'E) (see Fig. 1). Niger, and Senegal (see e.g. Van Damme 1984: Other material examined: Tanzania: Mbamba Bay, 56—58). Thus, the detailed discussion of C. Lake Malawi (11°16'S 34°46'E) (ZMB 104.815, leg. Lieder; aegyptiaca is not possible without considering 1 articulated specimen); (ZMB 104.816; syntype of Unio related bivalves from drainage systems in these lechaptoisi var. minor Martens; leg. Lieder; 1 articulated specimen); (ZMB 104.820, leg. Lieder; 1 articulated speci countries. This, however, is beyond the scope of men, 1 left valve); (SMF 13.497, leg. Lieder; 1 articulated the present study. Therefore, C. aegyptiaca and specimen); (SMF 5.014, leg. Lieder; 1 right valve). Manda, also C. teretiuscula in the Nile River (with the Manda Bay, Lake Malawi (10°28'S 34°34'E) (ZMB 104.818, leg. Fiillebom; 1 right valve). Ulanga, Ruaha River (a tribu latter presumably closely related to C. acuminata tary of the Rufiji River) (8°10'S 36°55'E) (ZMB 104.819, leg. and C. monceti) are not discussed in detail. Lieder; 1 articulated specimen, 1 right valve). Lake Rukwa With the exception of these species from the (ZMB 104.817, leg. Fiilleborn; 2 articulated specimen, 4 left and 5 right valves). Nile River system only two other species can be distinguished in the rivers of East Africa that Measurements: see Table 1. connect directly to the Great Lakes. These flu- Taxonomic remarks: Martens’ contribution viatile species are Coelatura mossambicensis and in the “Malakozoologische Blatter”, volume 6, Coelatura ratidota, which are both widely distrib was titled to appear “for the year 1859”, but uted but cannot be allocated to occur in one of actually was published in January of the sub the lakes. Thus, the species are here discussed sequent year, 1860, as is indicated in a footnote separately. by the printer on page 209, immediately preced Incomplete sampling of East African rivers for ing Martens’ account, starting on page 211, with these two species and the problem of frequent a list of those mollusks collected in Mozambique flooding events renders classification of their by Wilhelm C. H. Peters (1815—1883, who was 98 Scholz, H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853 Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 99
Table 1 deeply burried in the sediment to protect them Shell parameters (in mm) of the type specimens of Unio selves from environmental influences (e.g. pre mossambicensis and Unio liederi; LP = length of posterior part. dators and wave energy). In contrast, adult bi valves live shallow infaunal to semi-infaunal. length height LP This life habit exposes the individuals to higher ZMB 4.654a 42 26 32 water energy, for example. The differences in shell morphology between the “liederi”- and the ZMB 4.654b 32 20 24 23 15 17 “mossambicensis”-morphotype could also be re 14.5 9 10 lated to this change in life habits. However, a 29 17 20 quantitative sampling of the type locality of U 32.5 20.5 24 liederi has not been carried out to find transi ZMB 104.813 33 19 24 tional morphotypes between the “liederi”- and the “mossambicensis”-morphotype to test this hy ZMB 104.814 34.5 19 26 pothesis. SMF 9.670 17.5 10 13 Morphological observations: The shells of adult C. mossambicensis are elongate with generally well-rounded margins (elliptical shape). director of the Zoological Museum Berlin from Young individuals may have a straight dorsal 1857 to 1883). Thus, all citations referring to margin. Therefore, the dorsal margin pronoun “Martens (1859)” for this taxon, as, for example, cedly curves into the posterior and anterior most recently in Daget (1998), are erroneous. margin. Young shells tend to be wedge-shaped. Apparently, Martens based his description on a Sometimes the posterior ridge is relatively manuscript name given originally by Peters who strongly developed causing the formation of a had collected in Mozambique between 1842 and posterior wing. The periostracum is greenish or 1848. However, according to the rules of the brownish and often has radial colour pattern. ICZN the former is author of the name. The nacre is whitish. Coelatura mossambicensis Martens (1897) erected with Unio liederi a has a typical unionid dentition. The laterals are new species from the rivers of East Africa and thin and long, the pseudocardinals are also thin Lake Malawi which should be distinct from and long and are directed to the anterior end. Coelatura mossambicensis. However, only a few relatively small shells of U. liederi are known so Ecology: No detailed study of the ecology of far. Mandahl-Barth (1988) considered all indivi this species is available so far. The study of Mar duals of U. liederi as young C. mossambicensis. shall (1975) indicates that C. mossambicensis is a In contrast to the dorsally arched shells of C. riverine bivalve. mossambicensis, the shells of U. liederi have a Distribution: Common in the rivers of south straight dorsal margin. Therefore, they are lower ern Tanzania, in Malawi, and Mozambique; it than the shells of C. mossambicensis (Plate 1: has also been found in or close to Lake Malawi 3—4). The results of Mandahl-Barth (1988) indi and Lake Rukwa (Fig. 1); see under Remarks. cate that the shells of C. mossambicensis under go ontogenetic changes in shell morphology. Remarks: Although also reported from lacus Such ontogenetic changes are not unusual in un- trine habitats, it is not known whether reports ionoids. Eagar (1978) and Scholz (2003) dis e.g. by Martens (1897) who mentioned Coelatura cussed the morphologic changes from juvenile to mossambicensis from Lake Malawi actually refer adult shells in unionoid bivalves as related to to the lake proper as sampling site or to lagoons changes in life habits: Juvenile unionoids live and swampy areas immediately adjacent to the
< Plate 1. 1—6. Coelatura mossambicensis (Martens, 1860). 1. Lectotype (ZMB 4.654a); a: left valve; b: right valve; c: left valve interior; d: right valve interior; x l. 2. Paralectotype (ZMB 4.654b); a: left valve; b: right valve; x l. 3. Lectotype of Unio liederi (ZMB 104.813); a: left valve; b: right valve; x l. 4. Paralectotype of Unio liederi (ZMB 104.814); a: left valve; b: left valve interior; x l. 5. Syntype of Unio lechapteisi var. minor (ZMB 104.816); a: left valve; b: right valve; x l. 6. (ZMB 104.815); a: left valve; b: right valve; x l. 7. Coelatura ratidota (Charmes, 1885). Figured here is the holotype of Unio ambi- farius (ZMB 104.896); a: left valve; b: right valve; c: left valve interior; d: right valve interior; x l. 8—10. Coelatura acuminata (Adams, 1866). 8. (ZMB 104.892); a: left valve; b: right valve; c: left valve interior; d: right valve interior; x l. 9. (ZMB 104.892); a: left valve; b: right valve; x l. 10. (ZMB 104.893); a: left valve; b: right valve; x l. 11. Coelatura bakeri (Adams, 1866) (ZMB 104.861); a: left valve; b: right valve; c: left valve interior; x l. 100 Scholz, H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853 lake. Studies of molluscs from the western shore phology of C. ratidota with C. aegyptiaca could of Lake Malawi indicate that this ubiquitous spe also be accidental. A second argument against cies is common in the tributaries and marginal the relationship of C. ratidota with C. aegyptiaca waters of the lake but not in the lake itself is based on the distributional area of C. ratidota. (Berthold 1990, Gorthner 1992, Scholz 2003). The findings of Mandahl-Barth (1988) are based Marshall (1975) reported of C. mossambicensis on material found in the Athi River, in Kenya from Lake Mcllwaine from Zimbabwe. How near Nairobi, which is draining parts of the east ever, nothing is known about the relationships ern branch of the East African Rift System. The between the lower Zambezi specimens and those source of that river is east of the big volcanoes from Lake Mcllwaine. separating the drainage area of the Mediterra nean Sea (via Nile River and Lake Victoria) from the drainage area of the Indian Ocean. Coelatura ratidota (Charmes, 1885) No faunal connection between the distributional Plate 1: 7 area of C. aegyptiaca and the distributional area of C. ratidota is imaginable. In contrast to that, Unio ratidotus Charmes, 1885: 166. Unio ambifarius Martens, 1897: 225, pi. 7: 20 (Holotype the close relationship between C. ratidota and ZMB 104.896, leg. Stuhlmann; 1 articulated specimen; C. mossambicensis is indicated by the vicinity of Plate 1: 7; figured in Martens 1897: pi. 7: 1). Type locality: the borders of the distributional area of these “Dar-es-Salam”; Tanzania: Dar es Salaam (6=52'S 39C12'E). two species (Fig. 1). The northernmost occurence Type material: Holotype (MNHN); non vidi. of C. mossambicensis in the Ruaha River in Tan Type locality: Tanzania: Kingani River, near zania is close to the southernmost occurence of Bagamoyo (about 70 km north of Dar es Sa C. ratidota near Dar es Salaam. In times of laam). flooding due to extreme rainfall a temporal con Other material examined: No other than type materi nection between the two river systems appears al of Unio ambifarius was examined. to be possible. Thus, the types of C. ratidota Measurements: see Table 2. from the Dar es Salaam region could be conspe- cific with C. mossambicensis, as already sug Taxonomic remarks: In addition to Coela gested by Haas (1936, 1969), who considered not tura mossambicensis this is the only species from only C. ratidota but also U. liederi as a local var the rivers outside the Great Lakes accepted as iation of C. mossambicensis. However, in the ab valid. Haas (1936) has already synonymised the sence of adequate material of Coelatura from five species of Charmes (1885) from the Kingani rivers between Dar es Salaam in Tanzania and River and the Unio ambifarius of Martens Nairobi in Kenya that would allow to judge this (1897) because of similarities in shell morphol question, C. ratidota is maintained as a distinct ogy. He considered the holotype described here species herein. in as a young shell of C. ratidota. Nevertheless, the separation of C. ratidota as a distinct species Morphological observations: The only is problematic. Haas (1936) and Mandahl-Barth articulated specimen in the collection of Berlin is (1988) discussed the relationships of C. ratidota nearly rectangular in shell shape. Both ventral and C. mossambicensis. Haas (1936) considerd and dorsal margin are straight. The umbo is not C. ratidota to be closely related to C. mossambi prominent and is situated far away from the censis, whereas Mandahl-Barth (1988) separated anterior end of the shell; the shell is compressed. C. ratidota clearly from C. mossambicensis and This is the shell morphology typical for young placed the former in close relation to C. aegyp- shells of Coelatura. The periostracum is green tiaca. However, many species of Coelatura are with dark green radial colour pattern, the orna very similar to C. aegyptiaca because of the high mentation consists of faintly developed umbonal morphologic variability of the shells of that spe sculpture. The hinge of the specimen shows a ty cies. Therefore, the similarity of the shell mor- pical unionid dentition with thin pseudocardinals and laterals.
Table 2 Ecology: Ecological details of C. ratidota are Shell parameters (in mm) of the type specimen of Unio am unknown. bifarius; LP = length of posterior part. Distribution: This bivalve has been found in length height LP rivers of Tanzania (near Dar es Salaam) and ZMB 104.896 24 15 16.5 Kenya (Fig. 1). Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 101
Lake Albert Imprecise locality: Lake Albert (SMF 13.555, leg. Heim; 2 right valves), “angeblich Victoria-See” (Lake Albert) (SMF Lake Albert (5,600 km2) is situated between the 13.554, leg. Fulton; 1 articulated specimen, 1 left and 1 right valve). Democratic Republik of Congo and Uganda, has a length of approximately 150 km, a width Measurements: see Fig. 3. of 35 km, and a maximum depth of 56 m. Lake Taxonomic remarks: Because of the strik Albert, also known as Lake Mobutu, is a con ing shell morphology of C. acuminatus, which is necting link between the Lake Edward drainage quite different from most other unionid shells system (via the Semliki River) and the Lake from Lake Alberts no taxonomic confusion ex Victoria drainage (via Albert Nile), and, thus, ists. the Nile River system. Therefore, the bivalve Morphological observations: Despite the fauna of Lake Albert shows strong similarities similarities between C. acuminata and C. monceti with bivalves of the connected rivers and lakes. from Lake Victoria (see below) the separation of The Victoria Nile is one major affluent of Lake these two species is easily possible. Shells of Albert in its northern part. Before entering the C. acuminata are relatively large, relatively high, lake, the river passes the Murchison Falls with the straight dorsal and ventral margin running 30-35 m falls in a c. 50 m wide gauge. Cer nearly parallel, and the only slightly prosogyrous tainly, this waterfall prevents immigration of umbo is situated in a more central position than limnic animals from Nile River and Lake Albert in C. monceti (Fig. 3). The periostracum is into the upper Victoria Nile and Lake Victoria. brown, the sculpture covers only rarely most parts of the shell (Plate 1: 10). Coelatura acuminata (Adams, 1866) Ecology: Ecological details of C. acuminata Plate 1: 8-10; Plate 5: 1-2 are unknown.
Unio acuminatus H. Adams, 1866: 376. Distribution: Endemic to Lake Albert Type material: Holotype (BMNH 1867.1.9.4/1, leg. Ba (Fig-1). ker; 1 right valve; Plate 5: 1). Paratype (BMNH 1867.1.9.4/2, Remarks: The reference to the Upper Nile as leg. Baker; 1 right valve; Plate 5: 2). type locality in the files of the BMNH is prob Type locality: “Albert N’yanza” (= Lake Al ably a mistake. Not only did Adams (1866) refer bert); according to Adams (1866). However, in to Lake Albert as collecting locality of the mate the registration book of the BMNH the type spe rial Samuel White Baker brought back from cimens are refered to “?Upper Nile”; see below Central Africa, but typical Coelatura acuminata under Remarks. are to our knowledge restricted to this lake, Other material examined: Congo: Kasenye, Lake Al while in the Nile River C. teretiuscula with more bert (1°23'N 30°25'E) (ZMB 104.893, leg. Stuhlmann; 3 ar elongate shells is common. ticulated specimens, 3 left valves); (ZMB 104.892, leg. Schu- botz; 3 articulated specimens). Mahagi, Lake Albert (2°9'N 31°14'E) (SMF 13.553, leg. Heim; 4 articulated specimens). Coelatura bakeri (Adams, 1866) Plate 1: 11; Plate 5: 3—4 35 j E Unio bakeri H. Adams, 1866: 376. £ 30 -- Type material: Holotype (BMNH 1867.1.9.1/1, leg. Ba c ker; 1 left valve; Plate 5; 3). Paratype (BMNH 1867.1.9.1/2, 25 -■ o leg. Baker; 1 articulated specimen; Plate 5: 4). u. Measurements: see Fig. 4. implies a possible synonymisation of these lacus Taxonomic remarks: While Adams (1866) trine bivalves with C. aegyptiaca. This is true in compared Coelatura bakeri to Unio aferula Lea, particular for C. bakeri from Lake Albert. In 1864 (here synonymized with C. nyassaensis Lea, contrast to Lake Victoria and Lake Edward, no 1864 from Lake Malawi), according to Mandahl- faunal barriers separates, this lake from the Nile Barth (1988) this species is closely related to River and, thus, faunal exchange between Lake C. aegyptiaca. Therefore, any discussion of the Albert and the Nile River should be possible, taxonomic position of the former is not possible leading to a mixing of populations of C. aegyp without a detailed evaluation of the latter which tiaca and C. bakeri. While bivalves from Lake is, however, beyond the scope of the present Victoria and Lake Edward have the possibility study. Nevertheless, some remarks are given to enter Lake Albert, the reverse is not possible here on the unresolved problems associated with because of rapids and waterfalls. the taxonomy of C. bakeri, influenced also by In the absence of detailed anatomical and biogeographical implications. ecological studies, we here tentatively apply the Coelatura aegyptiaca is the most widely distrib classification of Daget (1998) to avoid further uted congeneric species in Africa. It occurs in confusion; accordingly C. bakeri is considered a the Nile River in Egypt (with the type locality) distinct species as well as C. stuhlmanni from and is also known from Chad, Niger, and Sene Lake Edward and C. hauttecoeuri from Lake gal where it shows a highly variable shell mor Victoria. Our treatment thus follows the concept phology (Daget 1998). Many species formerly already mentioned earlier when discussing the treated as distinct from C. aegyptiaca (e.g. C. distribution of C. mossambicensis. Consequently, tsadiana Martens, 1903 from Lake Chad) were we here propose that C. aegyptiaca as ubiquitous later synonymised. Based on similarities in shell fluviatile species mainly found in rivers, ponds or morphology, for example, Haas (1936, 1969) and smaller lakes might be a sister taxon to the more Mandahl-Barth (1988) assigned many of the restricted lacustrine C. bakeri which evolved in- Coelatura forms occurring in Western Africa to tralacustrine (and allopatrically) in the at times C. aegyptiaca. partly separated Lake Albert (see below under This is noteworthy, since rivers in Western Remarks). Africa are today not connected to the Nile River Morphological observations: The in System, while the unionid bivalves of Lake Vic flated shells of C. bakeri have a nearly rectan toria, Lake Albert, and Lake Edward occur in gular outline with a very prominent umbo. The water bodies directly connected to the Nile. colour of the periostracum varies from greenish However, these latter forms are generally consid to yellowish and brownish. Some shells are char ered as separate species or subspecies (Mandahl- acterised by radial colour pattern. These are the Barth 1988), albeit being closely related to C. shells very similar to C. aegyptiaca. However, the aegyptiaca. In addition to the biogeographical SMF holds several shells of Coelatura from Lake situation, the study of shell morphology also Albert that could be confused with elongate re presentatives of C. stuhlmanni (see below). They 30 are very elongate with a green periostracum (Fig. 5). These shells have no similarities with the 25 typical C. aegyptiaca. c - 15 O) <0 10 -£Z 5 - 0 -|------1------1------1 o 20 30 40 50 length in mm Fig. 4. Ratio of shell length and height (in mm) of 14 shells of Coelatura bakeri from the Museum of Natural History Berlin and 8 shells from the SMF. Fig. 5. Outlines of four elongate shells of Coelatura bakeri from SMF (x3/4). Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 103 Ecology: Ecological details of C. bakeri are however, properties of the Semliki River prevent unknown. counterdirectioned migration. With Coelatura stuhlmanni only one unionid Distribution: Endemic to Lake Albert (Fig. 1). bivalve species is known from Lake Edward. No Remarks: The elongate shells of C. bakeri in relatives of C. acuminata and C. monceti from Lake Albert are difficult to consider as being of the two other great lakes are detected so far. typical limnic bivalves. Usually, unionid bivalves in the Great Lakes of East Africa are relatively Coelatura stuhlmanni (Martens, 1897) small with a more or less triangular outline. In contrast, these bivalves are remarkably large and Plate 2: 1, 3 slender. The shells are also not very similar to Unio stuhlmanni Martens, 1897: 231, pi. 7: 13. fluviatile bivalves such as, for example, C. mos Unio ngesianus Martens, 1897: 234, pi. 7, fig 7 (Lectotype, sambicensis. However, without any detailed eco designated here in order to ensure the name’s proper and logical information the shell morphology of the consistent application, ZMB 104.891a, leg. Stuhlmann; 1 left valve; Plate 2: 2; figured in Martens 1897: pi. 7: elongate bivalves C. bakeri as well as C. stuhl 7. Paralectotypes ZMB 104.891b, leg. Stuhlmann; 1 left manni (see below) is difficult to interpret. and 1 right valve; figured in Martens 1897: pi. 7: 7. Para The reason for similarities between the lacus lectotypes SMF 5.010, apparently lost in World War II). Type locality: “Kissakka, NW Kiiste Ngesi (Albert-Ed trine C. bakeri and the riverine C. aegyptiaca ward) See”. could also be related to extrinsic factor such as Type material: Holotype (ZMB 104.867a, leg. Stuhl lake size. With increasing size of the lacustrine mann; 1 left valves; Plate 2: 1) from Vitschumbi. Paratypes: habitat the ecological differences of the lacus Congo: Vitshumbi, Lake Edward (ZMB 104.867b, leg. Stuhl trine habitats in relation to riverine habitats also mann; 2 right valves); Congo: Kiruwe, Lake Edward (0°35'S 29°20'E) (ZMB 104.865, leg. Stuhlmann; 1 right valve); Con increases. For this Lake Malawi, which is much go: Katerenge, Lake Edward (~0°35'S 29°18'E) (ZMB larger than Lake Albert, serves as a good exam 104.868, leg. Stuhlmann; 1 left valve; figured in Martens ple. As can be seen there, the differences in shell 1897: pi. 7: 13) and paratype (SMF 5.012, leg. Stuhlmann; 1 right valve; vidi). morphology between the lacustrine C. nyassaen- sis and the largely fluviatile C. mossambicensis Type locality: “Albert-Edward-See bei Vit from adjacent rivers are much more significant schumbi”; Congo: Vitshumbi, Lake Edward than differences found here between C. aegyptia (0°40'S 29°22'E). ca from the Nile and C. bakeri in Lake Albert. Other material examined: Imprecise locality: Lake Albert (Lake Edward?) (ZMB 104.869, coll. Rolle; 1 articu lated specimen). Lake Edward Measurements: see Table3. Lake Edward (2,150 km2) with a length of about Taxonomic remarks: The holotype (ZMB 65 km, a width of about 40 km, and a maximum 104.867a) of Coelatura stuhlmanni from Vit depth of 112 m was dicovered 1876 by H. M. shumbi at Lake Edward has been marked as Stanley and is named after Albert Edward, the “type” and mentioned as “the typical specimens” later Edward VII, king of Great Britain and Ire in Martens (1897: 232); however, Martens (1897: land between 1901 and 1910. Albert Edward was pi. 7: 13) figured another specimen, viz. ZMB the son of Queen Victoria and Prince Albert, the 104.868 from Katerenge. other forces behind the designation of the great Coelatura stuhlmanni is very similar in shell lakes in the region: Lake Victoria and Lake morphology to C. bakeri and C. aegyptiaca in Albert. Between 1889 and 1909 the lake was dicating possible conspecifity of these taxa. How- called Lake Albert-Edward, resulting in frequent confusion of older locality names of material Table 3 from Lake Albert (see above); currently, the Shell parameters (in mm) of the type specimens of Unio lake is also known as L. Rutanzige. stuhlmanni and Unio ngesianus; LP = length of posterior The Semliki River is the only outflow of Lake part, lv = left valve. Edward and connects it to Lake Albert to the length height LP north. From its origin the river is relatively shal ZMB 104.867a 43 25 30.5 low (3 m) and flows rapidly and turbulently over ZMB 104.867b 41 22 29 rocks and boulders. This makes faunal exchange ZMB 104.868 32 19 21 between Lake Edward and Lake Albert in re ZMB 104.865 45 - 33.5 SMF 5.012 36.5 21 24 cent times difficult. Only animals from Lake ZMB 104.891a 37 25 26 Edward can get to Lake Albert by accident, ZMB 104.891b, lv 31 19 21 104 Scholz, H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853 Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 105 ever, for C. bakeri it seems appropriate to keep Ecology: Ecological details of C. stuhlmanni it separate from C. aegyptiaca to date until more are unknown. material for anatomical, ecological, behavioural, Distribution: Endemic to Lake Edward and molecular studies becomes available (see (Fig- !)• above). Commonly, Unio ngesianus is synonymised Remarks: It was not possible to locate “Kis- with C. stuhlmanni (Daget 1998, Haas 1936, sakka, NW Kiiste Ngesi (Albert-Edward) See” Mandahl-Barth 1954). This is reasonable because on official maps. Because Kissakka must be situ the differences in shell morphology between ated on the northwestern shore of Lake Edward these two species named by Martens (1897) can it could be near the town Kasindi in Congo. be explained by ecological differences. In addi However, between Lake Victoria and Lake Kivu tion, confusion existed regarding the type materi a region is also called “Kissakka”. If the type al of U. stuhlmanni and U. ngesianus, of which material of U. ngesianus was collected in this re holotype and lectotype, respectively, are in the gion, the shells apparently stem from a river in ZMB. Paratypes of these two taxa were reported stead of coming from a lacustrine population. from the SMF collection in Frankfurt; however, However, this is improbable because the high this is not true. Haas (1936) mentioned SMF and nearly triangular shells are typical for shells 5.010 as the paratype of U. stuhlmanni, but ap from lakes. In this context it is worth mentioning parently this lot was lost in World War II. In that “Kissakka” in different spellings is appar contrast, the lot SMF 5.012 is still extant there. ently a very common locality name in African The single valve in this lot was considered the languages. Therefore, it is possible that several paratype of U. ngesianus by Haas (1936). How localities with this name exist today or have ex ever, SMF 5.012 is definitely a paratype of U. isted earlier on. stuhlmanni. The shell is very similar to the shells of ZMB 104.867. All shells were probably col Lake Victoria and adjacent drainage lected together and separated only later in the systems course of an exchange of material between ZMB Lake Victoria is the only lake with an incom and SMF (Zilch 1967). plete species record of Coelatura in the Museum Morphological observations: As men of Natural History of Berlin, since with C. al- tioned above, the shells of C. stuhlmanni are luaudi (Dautzenberg 1908) and C. cridlandi very similar to those of C. bakeri. Thus, it is diffi (Mandahl-Barth 1954) two unionid bivalves from cult to distinguish these two species without the this lake are not represent by any material. One knowledge of the origin of the shells. The forma specimen of C. alluaudi is present in the collec tion of the posterior ridge and the area are very tion of the Senckenberg Museum of Frankfurt, similar to those of C. burtoni from Lake Tanga and is discussed herein. The two other species of nyika (see below). However, the umbo is very Lake Victoria, viz. C. hauttecoeuri and C. mon swollen and more or less orthogyrous in contrast ceti, are well documented with extant material in to the petite prosogyrous umbo of those of C. ZMB. burtoni. The sculpture of C. stuhlmanni consists Despite its huge surface area of about of the typical strong zigzag ornamentation. The 70,000 km2, Lake Victoria is relatively shallow periostracum is greenish or brownish and is char with a maximum depth of 80 m. The lake, with acterised sometimes by radial colour pattern. 410 km in length and 250 km in width and nu •4 Plate 2. 1, 3. Coelatura stuhlmanni (Martens, 1897). 1. Holotype (ZMB 104.867a); a: left valve; b: left valve interior; x l. 3. Lectotype of Unio ngesianus (ZMB 104.891a); left valve; x l. 2. Coelatura alluaudi (Dautzenberg, 1908) (SMF 3.555); left valve; x l. 4—12. Coelatura hauttecoeuri (Bourguignat, 1883). 4. Lectotype of Unio multicolor (ZMB 104.855a); right valve; x l. 5. Paralectotype of Unio multicolor (ZMB 104.855b); a: left valve; b: right valve; c: left valve interior; d: right valve interior; x l. 6. Lectotype of Unio emini (ZMB 104.895a); a: left valve; b: right valve; c: left valve interior; d: right valve interior; x l. 7. (ZMB 104.886); a: left valve; b: right valve; x l. 8. (ZMB 40.418); a: left valve; b: right valve; x l. 9. (ZMB 40.418); right valve; x l. 10. (ZMB 104.857); left valve; x l. 11. (ZMB 104.853); left valve; x l. 12. (ZMB 104.853); left valve; x l. 13-14. Coelatura monceti (Bourguignat, 1883). 13. (ZMB 104.875); a; left valve; b: right valve; x l. 14. (ZMB 104.875); a: left valve; b: right valve; c: left valve interior; d: right valve interior; xl. 15—23. Coelatura burtoni (Woodward, 1859). 15. (ZMB 32.919); right valve; x l. 16. (ZMB 104.833); a: left valve; b: right valve; c: left valve interior; d: right valve interior; x l. 17. (ZMB 35.333); left valve; x l. 18. (ZMB 35.333); right valve; x l. 19. (ZMB 104.841); a: left valve; b: right valve; x l. 20. Syntype of Unio rostralis var. brevior (ZMB 104.831); right valve; x l. 21. (ZMB 104.841); right valve; x l. 22. Lectotype of Unio rostralis (ZMB 104.830a); left valve; x l. 23. Syntype of Unio burtoni var. sturanyi (ZMB 104.842); right valve; x l. 106 Scholz, H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853 merous bays and islands, is situated on a high Distribution: Endemic to Lake Victoria, and plateau >1,100 m above sea level between the is only known from the northeastern part of the two branches of the East African Rift System, lake (Fig. 1). According to Mandahl-Barth (1954, thus does not represent a typical rift lake such as 1988), this species is very rare. Lakes Tanganyika and Malawi. Coelatura hauttecoeuri (Bourguignat, 1883) Coelatura alluaudi (Dautzenberg, 1908) Plate 2: 4-12 Plate 2: 2 Unio hauttecoeuri Bourguignat, 1883: 5, figs 1—3. Unio multicolor Martens, 1897: 236, pi. 7: 4 (Lectotype, here Unio (Parreysia) alluaudi Dautzenberg, 1908: 26, pi. 2, designated in order to ensure the name’s proper and con Figs 13—16. sistent application, ZMB 104.855a, leg. Stuhlmann; 1 right Type material: Holotype (MNHN; non vidi). Paratypes valve; Plate2: 3. Paralectotype ZMB 104.855b, leg. Stuhl (MNHN; non vidi). Paratype (SMF 3.555, leg. Alluaud; 1 ar mann; 1 articulated specimen; Plate 2: 4). Type locality: ticulated specimen; Plate 2: 2). “Insel Sirwa, Victoria Nyansa”; Tanzania: Sirwa Island, Lake Victoria (~2°15'S 31°55'E). Type locality: Kenya, surroundings of Ki- Unio emini Martens, 1897: p. 224, pi. 7: 14 (Lectotype, here sumu (0°6'S 34°45'E), Kavirondo Bay, Lake Vic designated in order to ensure the name’s proper and con toria. sistent application, ZMB 104.895a, leg. Emin Pascha & Stuhlmann; 1 articulated specimen; Plate 2: 5; figured in Other material examined: No further material exam Martens 1897: pi. 7: 14. Paralectotypes ZMB 104.895b, leg. ined. Emin Pascha & Stuhlmann; 2 articulated specimen, 3 left and 4 right valves. Paralectotypes SMF 5.013, leg. Emin Measurements: seeTable4. Pascha & Stuhlmann; 1 left and 1 right valves; vidi). Type Taxonomic remarks: The taxonomic posi locality: “Messansa, Simin Fluss; SO Viet. Nyansa”; Tan zania: Masanza, Simin River (2°16'S 33°49'E). tion of Coelatura alluaudi has been discussed controversely in the past. Haas (1936, 1969) con Type material: Syntype (MNHN, leg. Hauttecoeur; 1 left sidered C. alluaudi as a synonym of Unio ruella- valve; vidi). ni Bourguignat 1883. Since U. ruellani is to be Type locality: Lake Victoria, southern part, synonymised with C. hauttecoeuri according to near the mouth of Liwoumbou River. Daget (1998), C. alluaudi might be conspecific with the latter. However, differences in shell Other material examined: Tanzania: Busisi, Mwanza Gulf (2°43'S 32°52'E) (ZMB 104.894, leg. Stuhlmann; 1 left morphology between C. hauttecoeuri and the and 1 right valve); (ZMB 104.866; 1 left and 2 right valves); types of C. alluaudi (see below) are regarded (ZMB 104.871, leg. Stuhlmann; 6 articulated specimens, 1 left here as being significant enough to reject this and 3 right valves). Nyamirembe (2°31'S 31°41'E) (ZMB 104.850, leg. Stuhlmann; 2 articulated specimen); (ZMB conclusion. Therefore, we agree with Mandahl- 104.884, leg. Stuhlmann; 8 articulated specimens, 4 left and 5 Barth (1954) who considered C. alluaudi as a dis right valves). Sirwa-Island (~2°15'S 31°55fE) (ZMB 104.853, leg. Stuhlmann; 2 articulated specimens). Kwa Kissero tinct species. (1°18'S 33°56'E) (ZMB 104.912, leg. O. Neumann; 1 articu Morphological observations: The stud lated specimen). Uganda: Bukoba (1°19'S 31°49'E) (ZMB 104.852, leg. O. Neumann; 1 articulated specimen); (ZMB ied shell is from a relatively young individual. 104.856, leg. Stuhlmann; 2 articulated specimen); (ZMB The shell is very thin and the hinge teeth are 104.859, leg. Stuhlmann; 2 articulated specimens); (ZMB very weak. The dorsal margin is straight and the 104.870, leg. Stuhlmann; 5 articulated specimens, 1 right valve). Sowe Island (0°10'N 32°38'E) (ZMB 104.854, leg. ventral margin strongly convex. The maximum Stuhlmann; 1 articulated specimen); (ZMB 104.858, leg. convexity is reached in the middle of the shell. Stuhlmann; 5 articulated specimen). Entebbe (0°4'N 32°28'E) The shell is very elongate and somewhat rostrate. (ZMB 104.872, leg. Schroder; 1 articulated specimen); (ZMB 104.916, leg. A. Hoffmann). Buddu (ZMB 104.873, leg. Stuhl In these characters the shells differ from typical mann; 4 articulated specimens); Bari, Buddu (ZMB 104.890, representatives of C. hauttecoeuri. The periostra- leg. Stuhlmann; 1 articulated specimen, 2 left and 2 right cum is greenish with radial colour pattern. valves). Kenya: Mhugu (~1°S 34°5'E) (ZMB 104.885, leg. O. Neumann; 3 articulated specimens, 2 left valves); (ZMB Ecology: Ecological details of C. alluaudi are 104.886, leg. O. Neumann; 1 articulated specimen); (ZMB unknown. 104.889, leg. O. Neumann; 4 articulated specimens, 7 left and 9 right valves); (ZMB 104.911; 1 left valve). Imprecise local ity: SW tip of Lake Victoria (ZMB 40.418, leg. Emin Effen- Table 4 di; 1 articulated specimen, 1 left and 1 right valve); (ZMB Shell parameters (in mm) of the paratype (SMF 3.555) of 40.418b, leg. Emin Effendi; 1 right valve). Surroundings of Unio (Parreysia) alluaudi', LP = length of posterior part. Kisumu (0°6'S 34°45'E), Kavirondo Bay (SMF 13.660, leg. Alluaud; 1 articulated specimen). Speke Gulf (ZMB 46.594, length height LP leg. Werther; 1 left valve). Lake Victoria (ZMB 104.857, leg. Emin Effendi; 1 left valve); (ZMB 104.887; 2 left and 1 right SMF 3.555 21 13 14.5 valve); (ZMB 39.253, leg. Fischer; 1 articulated specimen). “Amani”? (but corrected to Lake Victoria, see below under Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 107 Distribution) (ZMB 104.910, leg. Vosseler; 4 articulated spe posterior margins are straight. These characters cimens). Unknown locality: (ZMB 104.888; 3 articulated spe cimens, 1 right valve). are typical for Unio multicolor of Martens (1897). Apart of this morphotype a lot of varia Measurements: see Fig. 6. tions in shell shape and colour are possible. Taxonomic remarks: The types of Unio Worth mentioning are shells very similar to C. multicolor and U. emini differ at first sight signif monceti (see below). They have a well-rounded icantly from the type of C. hauttecoeuri. How ventral margin, the area is relatively small, the ever, in large samples of unionids from Lake zigzag sculpture is strong, and the periostracum Victoria all transitions between the types of is yellowish (type U. edwardsianus Bourguignat Martens (1897) and all other different “species” 1883). In these characters they differ from C. formerly defined (e.g. Bourguignat 1883) can be monceti. found. This highly developed morphologic varia Ecology: Ecological details of C. hauttecoeuri bility leads to the taxonomic conclusion that the are unknown. unionids in Lake Victoria, with the exception of the few specimens of C. alluaudi, are all repre Distribution: Endemic to Lake Victoria sentatives of C. hauttecoeuri. Some special fea (Fig. 1). The locality of some specimens men tures of Lake Victoria, such as the huge surface tioned above refer to the Biological-Agricultural area of the lake, the complex shoreline, and the Institute of Amani. This locality is far away from numerous big islands, could be responsible for Lake Victoria in E-Tanzania (5°06'S 38°38'E). the high morphologic variability. Therefore, it appears to be more appropriate to The articulated specimen SMF 13.660 is con consider the specimens as being found in Lake sidered as a syntype of Unio ruellani Bour Victoria but stored and/or sent out via Amani then guignat 1883 by Zilch (1967). However, the spe to actually consider Amani itself as sampling site cimen was collected later than other material of (see above under Remarks on collection). Bourguignat and could apparently not have been used in his study. Therefore, no type material of U. ruellani is deposited in the SMF. Coelatura monceti (Bourguignat, 1883) Plate 2: 13-14 Morphological observations: Mandahl- Barth (1988) considers this species as the most Unio monceti Bourguignat, 1883: 15, figs 13—15. variable species of the genus Coelatura. Many of Type material: Type repository of C. monceti unknown. the specimens described herein are nearly rec tangular in shell outline. The periostracum is Type locality: Lake Victoria. greenish and often has a radial colour pattern. Other material examined: Tanzania: Busisi (= Bussis- The ventral margin is convex, the dorsal and si), Mwanza Gulf (2°43'S 32°52'E) (ZMB 104.877, leg. Stuhl- 35 j 30 - 25 -■ 8 o E £ 20 -- o C. hauttecoeuri oo o OU. emini (lectotype) 15 - a) ■ U. emini (paralectotypes) A U. multicolor (lectotype) 10 - A U. multicolor (paralectotype) 5 -- 0 10 15 20 25 30 35 40 45 length in mm Fig. 6. Ratio of shell length and height (in mm) of 70 shells of Coelatura hauttecoeuri from ZMB. The lectotypes and paralec totypes of Unio emini (from ZMB) and Unio multicolor, respectively, are presented separately. 108 Scholz, H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853 mann; 2 right valves); (ZMB 104.898, leg. Stuhlmann; 1 ar Rwanda there is a direct connection from Lake ticulated specimen, 2 left valves). Nyamirembe (2 31'S 31°41'E) (ZMB 104.878, leg. Stuhlmann; 2 articulated speci Victoria to Lake Tanganyika. In contrast, the mens). Towalio (~1°S 31 \50'E) (ZMB 104.875, leg. Stuhl locality of some specimens again referring to mann; 2 articulated specimens). Uganda: Entebbe (0°4'N the Biological-Agricultural Institute of Amani 32°28'E) (ZMB 104.917, leg. A. Hoffmann). Bukoba (119'S 31°49'E) (ZMB 104.879, leg. Stuhlmann; 2 articulated speci seems more likely to be erroneous. Amani is mens). Sowe (= Soweh) Island (0°10'N 32°38'E) (ZMB far away from Lake Victoria in E-Tanzania 104.897, leg. Stuhlmann; 3 articulated specimens). Kenya: (5°06'S 38°38'E), and as argued above for speci Mhugu (~1°S 34 5'E) (ZMB 104.876, leg. O. Neumann; 3 articulated specimen, 2 left valves); (ZMB 104.880, leg. O. mens of C. hauttecoeuri it appears to be more Neumann; 3 left and 1 right valve). Rwanda: Mkunga River appropriate to consider the specimens as being near Ruasa (1°33'S 29 46'E) (ZMB 104.883, leg. Schubotz; stored in and/or sent out from the German sta 2 articulated specimens, 3 left and 2 right valves). Imprecise tion Amani then to consider Amani as sampling locality: “Tanganyika”? (corrected to Lake Victoria, see be low under Distribution) (ZMB 104.881, coll. Rolle; 1 articu site. lated specimen, 1 left valve). “Nyassa-See”? (Lake Victoria) (SMF 13.543, leg. Dautzenberg; 5 left and 5 right valves). Lake Victoria (ZMB 104.882, leg. Emin Pascha; 1 articulated Lake Tanganyika specimen); (ZMB 39.254, leg. G.A. Fischer; 1 articulated spe cimen, 1 right valve); (SMF 13.554, leg. Fulton; 1 articulated Lake Tanganyika in the western branch of the specimen, 1 left and 1 right valve); (SMF 13.555, leg. Heim; East African Rift System is the longest and sec 2 right valves). “Amani”? (corrected to Lake Victoria, see below under Distribution) (ZMB 104.914; 1 articulated speci ond deepest lake in the world. The lake is about men, 1 left valve). 670 km long and 1,471 m deep with a mean depth of 572 m. With an age of 9—12 million Measurements: see Fig. 3. years it is much older than Lake Malawi; for Taxonomic remarks: The shell morphology more details see e.g. Coulter (1991) and Cohen of C. monceti is very consistent, the morphologic et al. (1993). Three Coelatura species can be dis variability very low. Therefore, the classification tinguished in the lake. of unionid bivalves from Lake Victoria or else where to this bivalve is very clear. Also speci Coelatura burtoni (Woodward, 1859) mens from outside Lake Victoria can not be con fused with other species. This is really unique Plate 2: 15-23 within the unionids of Africa. Unio burtoni Woodward, 1859: 349, pi. 47: 1. Unio rostralis Martens, 1897: 238 (Lectotype, here designated Morphological observations: As men in order to ensure the name’s proper and consistent appli tioned earlier, C. monceti is similar to C. acumi cation, ZMB 104.830a, coll. Rolle; 1 left valve. Paralecto- nata. Exactly like C. acuminata, specimens of types ZMB 104.830b, coll. Rolle; 1 left and 1 right valve). Type locality: “Kala”; Tanzania: Kala, Lake Tanganyika C. monceti are lancet-shaped with straight and (8C7'S 30=58'E). parallel dorsal and ventral margins. However, the position of the umbo can be used to differ Type material: Type (BMNH 1859.12.23; non vidi) entiate between these two unionids (Fig. 3). The Type locality: Lake Tanganyika. Due to the periostracum in C. monceti is brown. route of Richard Burton and John Hanning Speke’s Expedition in 1858, who crossed this Ecology: Ecological details of C. monceti are lake from Ujiji in the east and called at several unknown. places along the northwestern shores, the locality Distribution: The occurence of C. monceti in cannot be restricted. a river in Rwanda (Fig. 1) makes the statement Other material examined: Burundi: “Usum of Daget (1998) that C. monceti is endemic to bura”, = Bujumbura (3°19'S 29°19'E) (ZMB 104.834, leg. Grauer; 1 articulated specimen). Tanzania: Kigoma (4°52'S Lake Victoria doubtful. The origin of another 29=37'e ) (SMF 1.194; 13 left and 8 right valves). Rusago problematic sample of the collection in Berlin near Ujiji (4°54'S 29°40'E) (ZMB 104.823, leg. Hosemann; (ZMB 104.881) is labelled as Lake Tanganyika. 1 right valve); (ZMB 104.824, leg. Hosemann; 1 right valve); (ZMB 104.829, leg. Hosemann; 21 left and 17 right valves). These specimens are very typical representatives Kawirola (5°55'S 29°57'E) (ZMB 104.832; leg. Hosemann; of C. monceti. Up to now, no representatives of 1 left valve). Karema (6°49'S 30°25'E) and [Cape] Mpimbue this species are known from Lake Tanganyika. (ZMB 104.827, leg. Hosemann; 1 articulated specimen); (ZMB 104.836, leg. Hosemann; 2 articulated specimen); It cannot be decided unequivocally whether the (ZMB 104.838, leg. Reichard; 2 left valves, 4 right valves); label is giving an erroneous location (with the (ZMB 104.839, leg. Hosemann; 1 left valve); (ZMB 104.843, specimens being actually from Lake Victoria), or leg. Hosemann; 1 right valve); (ZMB 104.844, leg. Hose mann; 2 left and 4 right valves); (ZMB 104.845, leg. Hose if C. monceti is not only restricted to Lake Vic mann; 1 left valve); (ZMB 32.920, leg. Gerrard; 1 left valve); toria. Via Lake Kivu and the Mkunga River in (ZMB 104.842, syntype of Unio burtoni var. sturanyi Mar- Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 109 tens; leg. Reichard; 1 right valve). Kala (8 7'S 30°58'E) men figured by Smith (1881) is very similar to the (ZMB 104.837, coll. Rolle; 1 right valve); (ZMB 104.831; specimen figured on Plate 2: 21. In contrast to syntype of Unio rostralis var. brevior Martens; coll. Rolle; 2 right valves); two days south of Kirando (7°25'S 30°40'E) the typical C. burtoni this specimen is only some (ZMB 104.909, leg. Hosemann; 4 left and 3 right valves). what lower. As for U. rostralis also here all tran Kassanga (8°28'S 31°8'E) (ZMB 104.825, leg. Hosemann; sitional morphotypes between U. tanganyicensis 1 left and 2 right valves); (ZMB 104.828, leg. Hosemann; 1 right valve). Uru-Island near Kassanga (8°28'S 31' 8'E) and C. burtoni are known (e.g. Plate 2: 18). (ZMB 52.271, leg. Glauning; 2 articulated specimens); (ZMB To summarise the discussion, no clear distinc 52.272, leg. Glauning; 1 articulated specimen). Congo: Al tive characters can be found to maintain more bertville (5°56'S 29°12'E) (SMF 13.651, leg. Bom; 33 valves). Between Vua (8°5'S 30°34'E) and Moliro (8°13'S 30°34'E) then one species. Therefore, all the species and (SMF 13.649, leg. Stoppers; 8 articulated specimens). Impre varieties discussed by Martens (1897) are syno- cise locality: Eastern shore of Lake Tanganyika (ZMB nymised here as C. burtoni, as done also by 52.273, leg. Glauning; 1 right valve). Lake Tanganyika (ZMB 35.333, leg. Bohm; 1 articulated specimen, 1 left and 1 right Mandahl-Barth (1988) and Daget (1998). valve); (ZMB 35.533, leg. Bohm; 1 articulated specimen, 1 left and 2 right valves); (ZMB 32.919, leg. Gerrard; 1 left Morphological observations: This is one and 3 right valves); (ZMB 104.840, leg. Gerrard; 1 articu of the most conspicuous representatives of Coe lated specimen); (ZMB 104.826, leg. Hosemann; 1 articulated specimen, 2 left and 3 right valves); (ZMB 104.833, coll. latura. Typical shells are characterised by a very Paetel; 1 left and 1 right valve); (ZMB 104.835, coll. Paetel; small and steep area posterodorsally of the sharp 1 left valve); (ZMB 104.841, leg. Reichard; 1 articulated spe ridge (e.g. Plate 2: 16). This is rather unique cimen, 1 right valve). within the genus Coelatura. The shell margins of Measurements: see Fig. 7. a typical shell of C. burtoni are well rounded and pass gradually into each other. However, the Taxonomic remarks: Martens (1897: 237— dorsal margin may be also straight or even con 238) discussed in detail the variability of the un cave (Plate 2: 22). Sometimes the posterior part ionids subsumed herein under C. burtoni, listing of the shell is clearly rostrate (Plate 2: 22). All three varieties named by Bourguignat and An- transitional morphotypes between the well cey, and naming an additional variety, viz. U. rounded, truncate posterior part and the rostrate burtoni var. sturanyi. He also erected a new spe posterior part are developed. The colour of the cies Unio rostralis, with one variety, viz. U. ros periostracum varies between grey, blue, brown tralis var. brevior. However, this variety has to ish, yellowish, and greenish with sometimes ra be considered as the transitional form or mor- dial colour pattern. The nacre is purple or blu photype between U. rostralis and a typical C. ish. The zigzag sculpture, typical for Coelatura is burtoni. Therefore, it is not possible to support not well developed. The growth rings are strong Martens’ (1897) opinion of the existence of two and narrow. In contrast to many other represen distinct species. The change in shell morphology tatives of Coelatura the umbo is pointed and from the “burtoni”- to the “re>s*ra//s”-morphotype clearly prosogyrous. The lunule is strongly devel is included within the spectrum of morphological oped. variability of C. burtoni. Another species separated for a long time Ecology: Leloup (1950) has already men from C. burtoni is U. tanganyicensis. The speci- tioned that C. burtoni exhibit no parasitic larval stage, in contrast to the majority of other union- oids. Kondo (1990) has studied the reproductive 30 j o biology of this bivalve in detail. He has found a 25 -- o ° reduced number of eggs and a large body size of o o o ■ 1 oo juvenile bivalves. This is typical for organisms | 20 - with direct development. Leloup (1950) also re C Z 15 - ferred to the environmental conditions, in parti .c <8°: O) #< cular sediment properties, as the factor responsi © 10 - -C ble for the formation of different morphotypes o C. burtoni 5 -- and a high morphologic variability. ■ U. rostralis (types) + + Distribution: Endemic to Lake Tanganyika 10 20 30 40 (Fig. 1). length in mm Fig. 7. Ratio of shell length and height (in mm) of 44 shells of Coelatura burtoni from ZMB and the two syntypes of Unio rostralis (ZMB 104.830a + b; left valve). 110 Scholz, H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853 Coelatura horei (Smith, 1880) Table 5 Shell parameters (in mm) of the shells of Coelatura horei Plate 3: 1-3; Plate 5: 5 from ZMB including the type specimens of Unio bohmi and Unio gerrardi; LP = length of posterior part, lv = left valve. Unio horei Smith, 1880: 351. Unio bohmi Martens, 1897: 223, pi. 7: 9. (Holotype ZMB length height LP 35.532, leg. Bohm & Reichard; 1 articulated specimen; Plate 3: 1; figured in Martens 1897: pi. 7: 9. Paratypes SMF ZMB 35.532 61.5 38 52 5.011, leg. Reichard; 1 left and 1 right valve; Fig. 8; vidi). SMF 5.011, lv 46 28.5 38.5 Type locality: “Tanganyika bei Karema ’; Tanzania: Kare- ZMB 32.910a 48.5 32 40.5 ma, Lake Tanganyika (6;49'S 30C25'E). ZMB 32.910b 51 31 39 Unio gerrardi Martens, 1897: 223, pi. 7: 5. (Lectotype, here ZMB 104.821 55 35.5 47 designated in order to ensure the name’s proper and con 45 29 37.5 sistent application, ZMB 32.910a, leg. Gerrard; 1 left valve; ZMB 104.822 32 21 27 Plate 3: 2; figured in Martens 1897: pi. 7: 5. Paralectotype ZMB 32.910b, leg. Gerrard; 1 right valve; Plate 3: 3; fig ured in Martens 1897: pi. 7: 5). Type locality: “Tanganyi ka”; Lake Tanganyika. can be given. Therefore, the different morpho Type material: Holotype (BMNH 1880.12.20.42, leg. types are subsumed here under C. horei as sug Thomson; 1 articulated specimen; Plate 5: 5; figured in Smith gested by Haas (1936, 1969). 1881: pi. 34: 37). Type locality: Lake Tanganyika. Morphological observations: Most of the shells decribed herein are from adult indivi Other material examined: Tanzania: Russago, nr Ujiji (4°54'S 29°40'E) (ZMB 104.822, leg. Hosemann; 1 right duals. The shells are remarkably large. All shells valve). Imprecise locality: Lake Tanganyika (ZMB 104.821, of the Museum of Natural History of Berlin leg. Hosemann; 2 left and 5 right valves); (SMF 13.623; were probably collected dead, because at least 3 articulated specimens). the periostracum is often strongly eroded. If pre Measurements: see Table 5. served, the periostracum of the shells is brown ish. The very prominent umbo is situated close Taxonomic remarks: Coelatura horei in to the anterior end. The dorsal margin is gener Lake Tanganyika is a representative of unionids ally straight, the ventral margin varies between most similar to C. aegyptiaca. This similarity is straight (“bohmi”-type) and strongly convex documented very well by the shells of the holo (“gerrardi”-type). The point of maximum ventral type of C. horei (Plate 5: 5), although the holo arching may be situated in the posterior part of type is from a young specimen. Also very similar the shell giving the shell a wedge-like shape. All to C. aegyptiaca are shells named as Coelatura the specimens have a typical palaeoheterodont aegyptiaca calathus in the Frankfurt collection dentition. (SMF 13.623), as illustrated in Fig. 8. Some specimens from Lake Tanganyika In earlier accounts this taxon was divided into named as Caelatura aegyptiaca calathus (SMF nearly 20 different “species”, including Unio ca 13.623) differ from the specimens described lathus Bourguignat 1885, U. bohmi Martens 1897, above. The shells are swollen and relatively high and U. gerrardi Martens 1897, for example. with a large area, the umbo is situated in a more Despite the differences in shell morphology central position (Fig. 8). With these features the Haas (1936) has synonymised these bivalves with shells are very similar to shells of C. aegyptiaca. C. horei. The shells named as Unio bohmi and U. gerrardi, by Martens (1897) are different from Ecology: Ecological details of C. horei are un C. aegyptiaca (see below for description of shell known. morphology). Without any ecological informa tion for the morphotypes under study no inter Distribution: Endemic to Lake Tanganyika pretation of the differences in shell morphology (Fig-1). ► Plate 3. 1—3. Coelatura horei (Smith, 1880). 1. Holotype of Unio bohmi (ZMB 35.532); a: left valve; b: right valve; c: left valve interior; d: right valve interior; xl. 2. Lectotype of Unio gerrardi (ZMB 32.910a); a: left valve; b: left valve interior; x l. 3. Paralectotype of Unio gerrardi (ZMB 32.910b); right valve; x l. 4—6. Coelatura ujijiensis (Crosse, 1881). 4. (ZMB 104.851); a: left valve; b: right valve; x l. 5. (ZMB 104.851); a: left valve; b: right valve; x l. 6. (ZMB 104.851); a: left valve; b: right valve; x l. 7—9. Coelatura hypsiprymna (Martens, 1897). 7. Lectotype (ZMB 104.808a); a: left valve; b: right valve; c: left valve interior; d: right valve interior; x l. 8. Paralectotype (ZMB 104.808b); a: left valve; b: right valve; x l. 9. Paralectotype (ZMB 104.808b); left valve; x l. 10—12. Coelatura nyassaensis (Lea, 1864). 10. (ZMB 104.802); a: left valve; b: right valve; x l. 11. (ZMB 104.630a); a: left valve; b: right valve; x l. 12. (ZMB 104.630a); a: left valve; b: right valve; x l. Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 111 112 Scholz, H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853 Coelatura ujijiensis (Crosse, 1881) Plate 3: 4—6 Unio nyassaensis var. tanganyicensis Smith, 1881: 298, pi. 34: 34a. Type material: Holotype (BMNH; specimen figured in Smith 1881: pi. 34; Fig. 34a; 1 left valve; vidi). Paratypes (BMNH, leg. Joseph Thomson; 2 left valves; vidi). Type locality: Ujiji, Lake Tanganyika. Other material examined: Congo: Mpala [at western shore] (6C45'S 29Q31'E) (SMF 10.396, leg. Guillemot; 1 ar ticulated specimen; figured in Haas 1936: pi. 7: 4). Imprecise locality: Lake Tanganyika (ZMB 104.851. coll. Rolle; 3 ar ticulated specimen). Measurements: see Table 6. Fig. 8. Outline of the paratype of Unio bohmi (SMF 5.011), filled grey, and the outlines of three shells of Coelatura horei Taxonomic remarks: This species is de (SMF 13.623), filled white (all x 3/4). scribed for the first time by Smith (1881) as Unio nyassaensis var. tanganyicensis. Crosse (1881) changed the name of this variety to U. nyassaen ence between C. ujijiensis and C. nyassaensis: sis var. ujijiensis because the name was preoccu The radial colour patterns are less striking in C. pied by U. tanganyicensis. Despite the similarities nyassaensis. in shell morphology of C. nyassaensis and U. Ecology: Ecological details of C. ujijiensis are nyassaensis var. ujijiensis the latter has to be con unknown. sidered as a separate species. The morphology of Distribution: Endemic to Lake Tanganyika the soft parts of C. ujijiensis is different from C. (Fig-1). nyassaensis (Mandahl-Barth 1972). In addition, no water connections within the last seven mil Lake Malawi and adjacent drainage lion years are known to explain the occurence of system C. nyassaensis both in Lake Malawi and Lake Tanganyika. After the uplift in the Rungwe vol Lake Malawi is the southernmost of the Great canic province due to increasing volcanic activity Lakes of the East African Rift System. The lake the two lake basins were separated and no fau- was formerly known also as Lake Nyasa or Lake nal exchange was possible. Sometimes the name Nyassa. It is about 560 km long, 75 km wide, of this species is misspelled as C. ujijensis (e.g. more than 700 m deep and, with the volume of Daget 1998). However, Crosse (1881) uses about 8,300 km3 the fifth largest lake in the clearly the name C. ujijiensis in the designation world (Eccles 1974). The age of Lake Malawi is of the species. about 4.0 to 4.5 million years. From that time the Morphological observations: The shell first lake sediments are known in the northern form of C. ujijiensis is very similar to some mor- part of the lake basin (e.g. Schrenk et al. 1993). photypes of C. nyassaensis. The dorsal and pos The Shire River, which is connected to the Low terior margins are nearly straight, the ventral er Zambezi River, is the only outflow of Lake and anterior margins are well rounded. The Malawi. The unionoid bivalve fauna of the lake umbo is prominent. The sculpture consists of consists of five species, three of them are union- the typical zigzag ribs covering most parts of ids belonging to Coelatura: C. hypsiprymna, C. the shell. The periostracum is green with dark- nyassaensis, and C. mossambicensis. The first two green radial colour pattern. This is the differ- species are endemic to the lake basin, the Shire River, the Lake Malombe, and the Lake Kisiwa. Table 6 Shell parameters (in mm) of the specimens of Coelatura uji jiensis from ZMB and SMF; LP = length of posterior part. Coelatura hypsiprymna (Martens, 1897) length height LP Plate 3: 7-9 ZMB 104.851 17.5 12 14.5 Unio hypsiprymnus Martens, 1897: 230, pi. 7: 1. 25 17 20 27 18 22.5 Type material: Lectotype, here designated in order to SMF 10.396 18.5 13.5 14.5 ensure the name’s proper and consistent application (ZMB 104.808a, leg. Lieder; 1 articulated specimen; Plate 3: 7; Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 113 figured in Martens 1897: pi. 7: 1). Paralectotypes (ZMB Barth 1972, 1988) as representing C. nyassaensis 104.808b, leg. Lieder; 4 articulated specimen, 1 left and (see below). 1 right valve; Plate 3: 8—9). Paralectotypes (SMF 5.009) were probably lost in World War II (see Zilch 1967). Morphological observations: The most Type locality: “Nyassa-See, in der Mbampa- important feature of C. hypsiprymna is the Bai” [Martens, 1897: 231; in error for Mbamba- strongly arched dorsal margin. It is the only Bai as correctly spelled, for example, in Fiille- bivalve from that region with this feature. Also born, 1900: 382]; Tanzania: Mbamba Bay, Lake characteristic is the brown periostracum and the Malawi (11°16'S 34°46'E) (see Fig. 1). zig-zag sculpture. The sculpture covers the whole shell. The shells are relatively short, the poster Other material examined: Tanzania: Lake Kisiwa (ZMB 104.812, leg. Fulleborn; 5 articulated specimen, 1 left ior and the anterior end are truncated, the ven valve). tral margin is nearly straight. Measurements: see Table7. Ecology: Ecological details of C. hypsiprymna are unknown. Taxonomic remarks: Apart from the type locality, Mbamba Bay, this bivalve is known only Distribution: Up to now, this bivalve is only from one other locality, Lake Kisiwa, where typi known from localities along the eastern shore of cal shells of C. hypsiprymna were found by Lake Malawi and Lake Kisiwa, a small lake Fulleborn (see above). However, Mandahl-Barth north of Lake Malawi (Fig. 1). (1972) considered a more elongate form with no dorsal arching as more common for this species. Coelatura nyassaensis (Lea, 1864) Problematic is the confusion of such elongate C. Plate 3: 10-12; Plate 4: 1-9 hypsiprymna with elongate C. nyassaensis (see below). Therefore, Mandahl-Barth discussed the Unio nyassaensis Lea, 1864: 108. hinge morphology and the size of the labial Unio kirkii Lea, 1864: 108 (type: USNM 84056; 1 articulated specimen; vidi; Plate 4: 2). Type locality: “Lake Nyassa, palps as distinctive characters. However, the Central Africa”; Lake Malawi. morphology of the hinge varies strongly. The Unio aferula Lea, 1864: 109 (type: USNM 84058; 1 articu study of more than 1,700 shells of Coelatura lated specimen; vidi; Plate 4: 3). Type locality: “Lake Nyas sa, Central Africa”; Lake Malawi. from Lake Malawi has lead to the result that a Nyassunio nyassaensis nyassaensis (Lea) — Woodward (in distinction of two species with the help of the Crowley et al.) 1964: 46, pi. 6, figs 37—38. hinge morphology is impossible (Scholz 2003). In Nyassunio ecclesi Woodward (in Crowley et al.), 1964: 52, pi. 6, figs 39—40. addition, the relative size of the labial palps also Grandidieria bloomeri Woodward (in Crowley et al.), 1964: does not allow unequivocally to separate C. hyp 53, pi. 7, figs 41-42. siprymna sensu Mandahl-Barth from C. nyas Indonaia mossambicensis (von Martens) — Woodward (in Crowley et al.) 1964: 55, pi. 7, figs 43—46. saensis. A discriminant function analysis of the Caelatura nyassaensis (Lea) — Appleton 1979: 161: 2e. shell morphology and the relative size of the la Caelatura hypsiprymna (von Martens) — Appleton 1979: 161: bial palps (small, medium, large) of 73 indivi 2f. Caelatura hypsiprymna (Martens) — Mandahl-Barth 1988: 21, duals is not significant for the two first discrimi figs 78-79. nant functions (Chi2-test, p > 0.05, n.s.) as is Caelatura nyassaensis (Lea) — Mandahl-Barth 1988: 21, figs discussed in more detail by Scholz (2003). There 83-85. fore, the taxonomic concept of Mandahl-Barth Type material: Holotype (USNM 84057; 1 articulated specimen; vidi; Plate 4: 1). Paratype (BMNH 64.5.14.3, leg. (1972) for the unionids of Lake Malawi is re Dr. Kirk; 1 articulated specimen; vidi). Paratypes (BMNH, jected here. Only few shells studied here belong leg. Dr. Kirk; 2 left and 2 right valves; vidi). to C. hypsiprymna while we tentatively re-identi- Type locality: “Lake Nyassa, Central Afri fy most of the other specimens (e.g. as men ca”; Lake Malawi. tioned in Appleton 1979; Haas 1936; Mandahl- Other material examined: Tanzania: Manda (Wied- hafen) (10°28'S 34°34'E) (ZMB 104.806, leg. Fulleborn; 1 ar Table 7 ticulated specimen, 2 left and 1 right valve); (ZMB 104.801, Shell parameters (in mm) of the type specimens of Coelatura leg. Fulleborn; 2 articulated specimen; (ZMB 104.847, leg. hypsiprymna; LP = length of posterior part. Fulleborn; 1 right valve); (ZMB 104.849, leg. Fulleborn; 1 ar ticulated specimen, 1 left valve); (ZMB 104.804, leg. Fulle length height LP born; 1 left and 1 right valve); Manda Bay (10°28'S 34°34'E) (ZMB 104.811, leg. Fiilleborn; 1 articulated specimen) (ZMB ZMB 104.808a 33 25 26 104.805, leg. Fulleborn; 1 articulated specimen, 2 left and ZMB 104.808b 23 17 17.5 1 right valve). Mbasi River near Mwaya (9°33'S 33°57'E) 30 22 23 (ZMB 104.809; 1 articulated specimen). Lumbira (9°34'S 28.5 20.5 22 34°7'E) (ZMB 104.810, leg. Fiilleborn; 2 articulated speci 35 24.5 — men); (ZMB 104.846, leg. Fiilleborn; 1 articulated specimen). 114 Scholz, H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853 Malawi: “Cambwe Lag.”, = Kambwe (see below under Re (PIW2002III 19, leg. Scholz; 1 articulated specimen); mark) (9°54'S 33°56'E) (ZMB 104.807, leg. Fiillebom; 1 ar (PIW2002III 20, leg. Scholz; 1 articulated specimen); ticulated specimen); (ZMB 104.800, leg. Fiillebom; 4 left and (PIW2002III 23, leg. Scholz; 1 articulated specimen); 2 right valves); (ZMB 104.848, leg. Fiillebom; 1 articulated (PIW2002III 24, leg. Scholz; 1 articulated specimen); specimen); (ZMB 104.802, leg. Fiillebom; 2 articulated speci (PIW2002III 35, leg. Scholz; 50 articulated specimens); men); (SMF 13.542, leg. Fiillebom; 1 right valve). Kande (PIW2002III 36, leg. Scholz; 23 articulated specimens); Beach (11°57'S 34°8'E) (PIW2002III 4, leg. Scholz; 1 articu (PIW2002III 37, leg. Scholz; 27 articulated specimens); lated specimen); (PIW2002III 7, leg. Scholz; 1 articulated (PIW2002III 38, leg. Scholz; 369 articulated specimens); specimen); (PIW2002III 9, leg. Scholz; 1 articulated speci (PIW2002III 39, leg. Scholz; 146 articulated specimens); men); (PIW2002III 18, leg. Scholz; 1 articulated specimen); (PIW2002III 40, leg. Scholz; 126 articulated specimens); (PIW2002III 22, leg. Scholz; 1 articulated specimen); (PIW2002III 42, leg. Scholz; 88 articulated specimens); (PIW2002III 25, leg. Scholz; 8 articulated specimens); (PIW2002III 52, leg. Scholz; 2 articulated specimens); (PIW2002III 26, leg. Scholz; 41 articulated specimens); (PIW2002III 53, leg. Scholz; 1 articulated specimen). Palm (PIW2002III 27, leg. Scholz; 36 articulated specimens); Beach, nr Mangochi (14°22'S 35°12'E) (ZMB 102.631, leg. (PIW2002III 28, leg. Scholz; 42 articulated specimens); Glaubrecht; 2 articulated specimens, 2 left and 1 right valve). (PIW2002III 29, leg. Scholz; 3 articulated specimens); Mangochi (14°28'S 35°16'E) (PIW2002III 10, leg. Scholz; (PIW2002III 43, leg. Scholz; 25 articulated specimens); 1 articulated specimen); (PIW2002III 41, leg. Scholz; 36 ar (PIW2002III 44, leg. Scholz; 15 articulated specimens); ticulated specimens). Lake Malombe (HLMD, leg. Gorthner; (PIW2002III 45, leg. Scholz; 36 articulated specimens); many articulated specimens). Lake Malawi, unknown locality (PIW2002III 46, leg. Scholz; 184 articulated specimens); (ZMB 104.803, coll. Paetel; 1 articulated specimen). (PIW2002III 47, leg. Scholz; 3 articulated specimens). Senga Bay (13°43'S 34=37'E) (ZMB 102.630a, leg. Glau Measurements: see Fig. 9. brecht; 4 articulated specimen, 1 right valve); (PIW2002III 11, leg. Scholz; 1 articulated specimen); (PIW2002III 17, leg. Taxonomic remarks: It was Lea (1864) Scholz; 1 articulated specimen); (PIW2002III 21, leg. Scholz; who for the first time described systematically 1 articulated specimen); (PIW2002III 33, leg. Scholz; 54 ar unionoid bivalves from Lake Malawi. He found ticulated specimens); (PIW2002III 51, leg. Scholz; 10 articu lated specimens). Namalenje Island (13 44'S 34D38'E) three species of unionids: Unio kirkii, U. nyas- (PIW2002III 2, leg. Scholz; 1 articulated specimen); saensis, and U. a ferula. Martens (1897) added an (PIW2002III 3, leg. Scholz; 1 articulated specimen); other three species: U. hypsiprymnus, U. mos (PIW2002III 5, leg. Scholz; 1 articulated specimen); (PIW2002III 6, leg. Scholz; 1 articulated specimen); sambicensis, and U. liederi (see above). Two new (PIW2002III 13, leg. Scholz; 1 articulated specimen); species of Woodward (in Crowley et al. 1964) (PIW2002III 31, leg. Scholz; 56 articulated specimens); have also been described from Lake Malawi: (PIW2002III 34, leg. Scholz; 252 articulated specimens). Kambiri Point (13 46'S 34°37'E) (ZMB 104.899, leg. Scholz; Nyassunio ecclesi and Grandidieria bloomeri. 7 articulated specimens in ethanol); (ZMB 104.906, leg. Except for the three bivalves of Martens (1897) Scholz; 1 articulated specimen in ethanol); (PIW2002III 30, all mentioned species can be synonymised with leg. Scholz; 8 articulated specimens); (PIW2002III 32, leg. Scholz; 1 articulated specimen); (PIW2002III 48, leg. Scholz; Coelatura nyassaensis. As discussed in detail by 10 articulated specimens); (PIW2002III 49, leg. Scholz; 33 ar Scholz (2003) the shells of U. kirkii and U. nyas ticulated specimens); (PIW2002III 50, leg. Scholz; 2 articu saensis of Lea (1864) have to be considered as lated specimens). Between Nanchengwa Lodge and Boad- zulu Island (14°15'S 35°8'E) (PIW2002III 1, leg. Scholz; 1 extreme morphologies of the morphospace of articulated specimen); (PIW2002III 8, leg. Scholz; 1 articu C. nyassaensis. All transitional morphotypes be lated specimen); (PIW2002III 12, leg. Scholz; 1 articulated tween these extreme forms can be found. The specimen); (PIW2002III 14, leg. Scholz; 1 articulated speci men); (PIW2002III 15, leg. Scholz; 1 articulated specimen); shell of U. aferula of Lea (1864) is more proble (PIW2002III 16, leg. Scholz; 1 articulated specimen); matic. No similar shells could be found in Lake o C. nyassaensis (ZMB) ■ U. kirkii (USNM 84056) a C. nyassaensis (USNM 84057) • U. aferula (USNM 84058) length in mm Fig. 9. Ratio of shell length and height (in mm) of 27 shells of Coelatura nyassaensis from ZMB and three type specimens of Unio taxa from USNM. Mitt. Mus. Nat.kd. Bcrl.. Zool. Reihe 80 (2004) 1 115 Malawi in the past. However, the morphologic Mandahl-Barth (1972), who presented the most variability of C. nyassaensis is extremely high, recent taxonomic study of Malawian molluscs. Therefore, it appears to be more appropriate to Mandahl-Barth (1972) also suggested to synony- consider the shell of U. aferula as a variety of C. mise N. ecclesi Woodward 1964 with C. nyassaen- nyassaensis rather than to maintain this bivalve sis. Scholz (2003) has found that the shells of as a separate species, which is in accordance with N. ecclesi are only ecological varieties of C. nyas- Tyf>‘ 1d 9 ^ . Plate 4. 1—9. Coelatura nyassaensis (Lea, 1864). 1. Holotype (USNM 84.057); a: left valve; b: right valve; c: left valve interior; right valve interior; x l. 2. Type of Unio kirkii (USNM 84.056); a: left valve; b: right valve; c: left valve interior; right valve interior; x l. 3. Type of Unio aferula (USNM 84.058); a: left valve; b: right valve; c: left valve interior; right valve interior; x l. 4. (ZMB 104.803); a: left valve; b: right valve; c: left valve interior; right valve interior; x l. 5. (ZMB 104.810); left valve; x l. 6. (PIW2002III 11); a: left valve; b: right valve; x l. 7. (PIW2002III 9); a: left valve; b: right valve; x l. 8. (PIW2002III 12); a: left valve interior; b: right valve interior; x2. 9. (PIW2002III 10); left valve interior; x2. 116 Scholz. H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853 Plate 5. 1—2. Coelatura acuminata (Adams, 1866). 1. Holotype (BMNH 1867.1.9.4/1); a: right valve; b: right valve interior; x l. 2. Paratype (BMNH 1867.1.9.4/2); a: right valve; b: right valve interior; x l. 3 -4. Coelatura bakeri (Adams, 1866). 3. Holotype (BMNH 1867.1.9.1/1); a: left valve; b: left valve interior; x l. 4. Paratype (BMNH 1867.1.9.1/2); a: left valve; b: right valve; c: left valve interior; d: right valve interior; x l. 5. Coelatura horei (Smith, 1880). Holotype (BMNH 1880.12.20.42); a: left valve; b: right valve; c: left valve interior; d: right valve interior; x l. saensis. In offshore habitats (e.g. 2 km from the (Plate 4: 6), the colour of the periostracum from shore in more than 10 m water depth) these yellowish to greenish and brownish, the colour shells are very common. of the nacre from white to deep purple. The In contrast to Mandahl-Barth (1972) C. bloo shells may have zig-zag ornamentation covering meri Woodward 1964 is here synonymised with the whole shell or may be smooth. The periostra C. nyassaensis. The shells of the type material of cum may be shining or not. Greenish shells have G. bloomeri from Tervuren (MRAC 793.222, generally green radial colour pattern, in particu 793.223; vidi) are in very poor condition. In par lar in the anterior part of the shell. Occasionally ticular the shells of the holotype are strongly a sulcus is developed in the posterior part of the eroded. Mandahl-Barth (1972) synonymised this ventral margin (Plate 4: 4). The umbo may be bivalve with C. hypsiprymna. However, the shells directly at the anterior end of the shell or in a of the paratypes in particular are more similar to more central position. In general, the posterior the shells of C. nyassaensis presented here. umbonal ridge is strongly developed in the tri Therefore, the shells of G. bloomeri are consid angular morphotypes, the area is small and ered to be representatives of C. nyassaensis. steep. The rectangular forms have a larger area. The type material of Lea covers the most typical Morphological observations: The shells morphotypes. However, all transitional morpho may vary considerably in shape, the outline vary types between forms described by Lea are known from triangular (Plate 4: 7) to rectangular (Scholz 2003). Table 8 The number of unionid species (including subspecies and varieties) in the lakes of the East African Rift System and the adjacent drainage systems from relevant literature compared to results of the present study; asteriks marks the three species from Lake Victoria dealt with in this paper, to which C. cridlandi not present in the ZMB collection, has to be added. Martens Pilsbry & Bequaert Haas Mandahl-Barth Daget this study 1897 1927 1936/1969 1988 1998 rivers 10 - 3 2 2 2 Lake Albert 2 2 2 3 2 2 Lake Edward 2 3 1 1 1 1 Lake Victoria 8 — 5 4 4 3* Lake Tanganyika 13 23 4 3 3 3 Lake Malawi 5 — 3 2 2 2 Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 117 IThe dentition is typical for the limnic species of Discussion Coelatura. The cardinals are slashed. Scholz (2003) showed that transposed hinges are rare Taxonomy among this species. One example of a transposed hinge is shown on Plate 4: 8. Also curious varia In the present study we consider as valid a total tions of the dentition are possible (Plate 4: 9). of 14 species of Coelatura bivalves, with 12 spe cies from the Great Lakes of the East African Ecology: The bivalves live semi-infaunal to in- Rift System and an additional two species from faunal on sandy substrates. They are absent on the adjacent drainage systems; a compilation of rocks. They cannot live in strongly wind-exposed these taxa is given in the Appendix (see there). habitats, because wave energy is too high, which Accordingly, the number of species recognised causes transport of living bivalves away from herein is lower than in former studies (see their habitats. In suitable habitats this bivalve Table 8). For example, Martens (1897) accepted dominates the bivalve fauna on the lake bottom. and discussed 40 species, subspecies and varieties Very small individuals are apparently deeply bur from this region. Many of these bivalves are ned: they could not be encountered from Lake synonymised today with C. burtoni, C. horei, C. Malawi. The shells of C. nyassaensis show the mossambicensis, and C. ratidota (Daget 1998). big river effect (Scholz 2003). This phenomenon Pilsbry & Bequaert (1927) mention 23 unionid is so far only known from the big rivers of North species in Lake Tanganyika. Most of them are America (e.g. Ortmann 1920, Watters 1994). considered today as synonyms of C. burtoni and Also the colour of the periostracum and the C. horei (Daget 1998). The number of 19 species nacre changes with changing environmental con and subspecies accepted by Haas (1936, 1969) is ditions. The most important factor controlling closer to the current number of species. Finally, the abundance and shell morphology of C. nyas Mandahl-Barth (1988) and Daget (1998) reduced saensis is habitat stability. the number of unionid bivalves to 15 and 14, re Distribution: This bivalve is known so far spectively, for the region in question. In contrast from Lake Malawi, Lake Malombe, and the to Daget (1998), Mandahl-Barth (1988) accepted Shire River between Lake Malawi and Lake and discussed the occurrence of C. aegyptiaca in Malombe (Fig. 1). Lake Albert (for more details see under the spe Remarks: According to Smith (1881), who re cies). Of the 11 specific taxa originally described ferred to material collected at both Lake Tanga by Martens only three are recognized herein as nyika and Malawi (= Nyassa) by J. Thomson, C. valid species, viz. C. mossambicensis, C. hypsi- nyassaensis is also common in Lake Tanganyika. prymna and C. stuhlmanni, whereas the names However, the specimens mentioned are to be as of the remaining eight of his taxa are synony signed to C. ujijiensis. mised with the currently accepted valid Coela In the 1890s several German explorers visited tura species of East Africa; see list A in the Ap the region of northern Malawi. Among them was pendix. the physician Dr. Fiillebom (see above) who Since this survey focuses on the much better ex noted, presumably in his original handwriting on plored Eastern African area, we here refrained a label in one lot with C. nyassaensis (ZMB from discussing the unresolved taxonomic and 104.848), “Cambwe Lag.fune]” as locality. Mar other issues of Coelatura species found in the tens transcribed this as “Lambwe” on this and Congo drainage system. It should be mentioned, other labels of the relevant lots (see above), however, that according to Daget (1998) an addi obviously in error for Cambwe. This locality is tional six species are found in the Congo Basin, given on a map of Kohlschliitter & Glauning including the adjacent and interconnected Lakes of the German-English Tanganyika-Expedition Bangweulu and Mweru, viz. C. briarti, C. chozien- (,Staatsbibliothek, Humboldt University, Karten- sis, C. gabonensis, C. kipopoensis, C. leopoldvillen- lesesaal, Invent.-no. C16747/4) as “Kambwe” and sis, C. luapulaensis. In an earlier account, Man “Kambwe Lagun”, respectively; it is also referred dahl-Barth (1988) listed two more species, viz. C. to as “Kambue” on a map given in Bornhardt bourguignati and C. mweruensis. (1900), reporting that this was then the only sui The reason for these changes in classification table harbour at the shores of the northern Lake can be seen (i) in the typological approach of Malawi, located on English territory. With this traditional 19th century conchology (see Glaub information we verify the occurrence of this tax- recht 2003a, 2004, for a more elaborate discus on on the NW shores of Lake Malawi. sion), in concert with (ii) the high variability in 118 Scholz, H. & M. Glaubrecht, Toward a revision of the unionid bivalve Coelatura, 1853 shell morphology in combination with low sam species). It should be noted, thus, that the maxi ple sizes. The study of Scholz (2003) has shown mum number of endemic Coelatura species cap that hardly any shell character can be used to able of living in one of the great African lakes differentiate unambiguously between species. In appears to be around three. Despite extremely addition, several transitions between extreme different lacustrine settings represented by these morphotypes within a single species can be lakes — i.e. deep trough-like rift lakes such as found in larger series. Thus, since changes in Tanganyika and Malawi of ancient origin with shell morphology within one species are gradual 9—12 and 4—4.5 myr., respectively, versus a the factual evidence for high morphological shallow lake of obviously much more recent variability requires large sample size. Scholz origin in Lake Victoria that apparently has was (2003) studied 1,713 shells of Coelatura from 30 dessicated more or less completely around different sampling sites in three different regions 15,000 years ago — the number of Coelatura spe along the shore of Lake Malawi. Apart from cies does not vary between these lakes in the that of Marshall (1975) no other study in the same magnitude as cichlids or gastropods, for ex past is known to be based on the study of large ample. collections. However, large collections are neces The distribution of Coelatura mossambicensis sary to distinguish between common morphologi and C. ratidota can be interpreted as being indi cal variations and biological species. Because the cative of the possibility that rivers in East Africa smaller the series the more likely transitional were an important source for unionid colonisa morphotypes are lacking, the extreme morpho tion of the lakes, irrespective of the fact that types were often considered as distinct species. today a faunal exchange between some of the Consequently, lack of suitable material series has inhabited water bodies is not easily possible. For lead in earlier studies to overestimation of spe example, C. mossambicensis occurs in the Rufiji cies diversity in the African Great Lakes and the River System and the Lower Zambezi River, but East African rivers. not in Lake Malawi (Fig. 1). The Murchison Cat aracts and the Kapachira Falls in the Lower Biogeography Shire River are known as an effective faunal barrier between the southern and northern dis Apart from the two ubiquitous species Coelatura tribution area (Beadle 1981), and, apparently, at mossambicensis and C. ratidota that are widely least today Lake Malawi serves as faunal barrier distributed throughout the East African drainage between rivers of Malawi, Tanzania, and Mozam system (see Fig. 1), all other species are endemic bique. All this suggests that C. mossambicensis to their respective lacustrine environment. Ac already reached its current distribution prior to cordingly, the majority of the 14 species under the formation of the Malawi Rift, and that rifting study occur in only one of the Great Lakes of in Malawi separated the former continuous the Rift system; compare the compilation accord range of this species, while endemic taxa might ing to distribution in Appendix B. However, it have evolved within the new lacustrine environ has to be noted that some of these species at ment when Lake Malawi began to form. least sometimes also occur in associated water However, given the lack of any anatomical bodies. An exception to this above stated ecolo and molecular genetical data, and, thus, phylo- gical rule is C. nyassaensis that has not only genetical analyses, the orgin and biogeography been found in Lake Malawi proper and the adja of Coelatura species remains speculative to date. cent and closely connected Lake Malombe, but also in the Shire River by Scholz (2003). Conclusion Interestingly, the number of species per lake shows a nearly equal distribution that can be Except for taxonomic investigations, only very roughly correlated with lake size. While Lake few studies dealed with ecological, biogeographi- Edward harbours only one species (C. stuhlman cal, or even phylogenetic aspects of the limnic ni) and Lake Albert is inhabited by two species, bivalves in East African lakes; see e.g. Kondo in the two largest lakes, viz. Victoria and Tanga (1984, 1990) and Scholz (2003). Also, no detailed nyika, four and three endemic species occur molecular studies are available to date. How (Appendix B). In contrast, Lake Malawi har ever, given the high degree of morphological dis bours only two endemic species, but in addition parity as well as possible inter- and intraspecific the widely distributed C. mossambicensis also en variability of these unionid bivalves, we consider ters the lake at least marginally (see under the such a modern approach to be a necessary prere- Mitt. Mus. Nat.kd. Berl., Zool. Reihe 80 (2004) 1 119 quisit for a comprehensive and thorough revision Bornhardt, W. 1900. Deutsch-Ost-Afrika. Wissenschaftliche of African unionids. Consequently, the present Forschungsresultate tiber Land und Leute unseres ost- afrikanischen Schutzgebietes und der angrenzenden study — in providing the basis by evaluation of Lander. Vol. VII. Zur Oberflachengestaltung und Geolo- relevant type material — can only be considered gie Deutsch-Ostafrikas. — 595 pp.; Berlin (Dietrich Rei- a necessary first step toward a systematic revi mer). Bourguignat, M. J. R. 1883. Mollusques fluviatiles du Nyanza sion of the Coelatura in East Africa. Oukerewe (Victoria-Nyanza), suivis d’une note sur les genres Cameronia et Burtonia du Tanganyika. - 29 pp., 1 pi.; Paris (Jules Tremblay). Braun, K. 1931. Meine erste Reise mit J. Vosseler in Acknowledgements Deutsch-Ostafrika. — Der Zoologische Garten, N.F. 4 (Heft 10/12): 370-375; Leipzig. We are thankful to A. Campbell, J. Pickering and K. Way Bredekamp, H., Briining, J. & Weber, C. 2000. Theatrum Na (all BMNH) as well as R. Janssen (SMF) who facilitated ac turae et Artis — Wunderkammem des Wissens. 2 vols. — cess to the museum collections in their charge. R. Hershler 311 + 280 pp.; Berlin (Henschel). (USNM) loaned additional specimens. R. Jocque, D. van den Brown, D. S. & Mandahl-Barth, G. 1987. Living molluscs of Spiegel (both MRAC), V. Heros and B. Metivier (both Lake Tanganyika: a revised and annotated list. - Journal MNHN) provided information and photographs of speci of Conchology 32 6: 305—327; London. mens from material in their collection. V. Heinrichs (Berlin) Casati, G. 1891. Ten years in Equatoria and the return with and B. Schonig (Wurzburg) helped with photographic docu Emin Pasha. 2 vols. — 340 + 365 pp.; London. mentation. We also thank L. Maitas, R. Piske and I. Kilias Charmes, X. 1885. Unionidae des environs de Bagamoyo for technical assistence with the material in the ZMB collec (Zanguebar). — Bulletin Societe Malacologiques de Fran tion. Mrs Ingeborg Kilias also deserves our special gratitude ce 2: 165-174. again for her indispensable help with literature research, for Cohen, A. S., Soreghan, M. J. & Scholz, C. A. 1993. Estima deciphering old museum labels and tracking down numerous ting the age of formation of lakes; an example from Lake obscure locality names in various maps and expedition ac Tanganyika, East African Rift System. — Geology 21: counts, thus helping to resolve the many mysteries of the 511—514; Boulder. Berlin bivalve collection. We thank Alexei Korniushin for Conrad, T. A. 1853. A synopsis of the family of Naiades of important comments helping to improve the manuscript. The North America, with notes, and a table of some of the English of the text was approved by C. Gans. 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Coelatura ujijiensis (Crosse, 1881) — Lake Tanganyika Verheyen, E., Salzburger, W., Snoeks, J. & Meyer, A. 2003. Origin of the superflock of cichlid fishes from Lake Vic B — according to geographical distribution toria, East Africa. — Science 300: 325—329. Watters, G. T. 1994. Form and function of unionoidean shell East African drainage system sculpture and shape (Bivalvia). — American Malacologi- Coelatura mossambicensis (Martens, 1860) cal Bulletin 11: 1—20; Houston. Unio liederi Martens, 1897 West, K. & Michel, E. 2000. The dynamics of endemic di Coelatura ratidota (Charmes, 1885) versification; molecular phylogeny suggests an explosive Unio ambifarius Martens, 1897 origin of the thiarid gastropods of Lake Tanganyika. In Lake Albert Rossiter, A. & Kawanabe, H. (eds), Ancient Lakes: Bio Coelatura acuminata (Adams, 1866) diversity, ecology, and evolution. — Advances in Ecologi Coelatura bakeri (Adams, 1866) cal Research 31: 330—354; London (Academic Press). Woodward, S. P. 1859. On some new freshwater shells from Lake Edward Central Africa. — Proceedings of the Zoological Society Coelatura stuhlmanni (Martens, 1897) of London, 1859 (part 2): 348—350, pi. 47; London. Unio ngesianus Martens 1897 Zilch, A. 1967. Die Typen und Typoide des Natur-Museums Lake Victoria Senckenberg, 39: Mollusca, Unionacea. — Archiv fur Coelatura alluaudi (Dautzenberg, 1908) Molluskenkunde 97: 45—154; Frankfurt/Main. Coelatura cridlandi (Mandahl-Barth, 1954) [not studied herein] Coelatura hauttecoeuri (Bourguignat, 1883) Unio multicolor Martens 1897 Appendix Unio emini Martens 1897 Coelatura monceti (Bourguignat, 1883) Lake Tanganyika List of East African Coelatura species and their synonymies Coelatura burtoni (Woodward, 1859) as specified in the present paper, based on the evaluation of Unio rostralis Martens 1897 type material mainly from Eduard von Martens (1860, 1897), Coelatura horei (Smith 1880) indicated in bold (in list A only). Unio bohmi Martens 1897 Unio gerrardi Martens 1897 A — species in alphabetical order Coelatura ujijiensis (Crosse, 1881) Coelatura acuminata (Adams, 1866) — Lake Albert Lake Malawi Coelatura alluaudi (Dautzenberg, 1908) — Lake Victoria Coelatura hypsiprymna (Martens 1897) Coelatura bakeri (Adams, 1866) — Lake Albert Coelatura nyassaensis (Lea, 1864) Coelatura burtoni (Woodward, 1859) — Lake Tanganyika Unio aferula Lea, 1864 Unio rostralis Martens 1897 Unio kirkii Lea, 1864 Coelatura cridlandi (Mandahl-Barth, — Lake Victoria Grandidieria bloomeri Woodward, 1964 1954) [not studied herein] Nyassunio ecclesi Woodward, 1964