A SURVEY OF THE FISHES OF UPPER OKAVANGO RIVER SYSTEM (CUITO AND KWANDO RIVERS) IN ANGOLA

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Alexina Spencer
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and Francisco Almeida 2 ( 1 South African

1 A SURVEY OF THE FISHES OF UPPER OKAVANGO RIVER SYSTEM (CUITO AND KWANDO RIVERS) IN ANGOLA SAIAB Investigational Report No. 74. By Roger Bills 1, Nkosinathi Mazungula 1 and Francisco Almeida 2 ( 1 South African Institute for Aquatic Biodiversity, 2 INIP)

2 This report should be cited as follows: Full title of report: A Survey of the Fishes of Upper Okavango River System in Angola. Authors: Roger Bills, Nkosinathi Mazungula and Francisco Almeida. South African Institute for Aquatic Biodiversity (SAIAB) Investigational Report No. 74. Name of client: Southern Africa Regional Environmental Program (SAREP), Maun, Botswana. COPYRIGHT INFORMATION This document contains intellectual property and property information that is protected by copyright in favour of the South African Institute for Aquatic Biodiversity and the specialist consultants. The document may therefore not be reproduced, used or distributed without the prior written consent of the South African Institute for Aquatic Biodiversity. This document is prepared exclusively for submission to SAREP and is subject to all confidentiality, copyright and trade secrets, rules, intellectual property law and practices of Botswana. Southern Africa Regional Environmental Program (SAREP) P.O. Box 2313, Former Bull & Bush, Airport Road, Airport Industrial Site, Maun, Botswana. Tel: , Fax: , Cell: South African Institute for Aquatic Biodiversity (SAIAB), Private Bag 1015, Somerset Street, Grahamstown South Africa. Telephone: +27 (046) , FAX: +27 (046) , r.bills@saiab.ac.za, Website: 2 Instituto Nacional de Investigacao Pesqueira (INIP), Av. Murtala Mohamed. C.Postal: 2601, Ilha de Luanda, Luanda, Angola. Telephone: , FAX: franciscoalmeida462@gmail.com ii

3 TABLE OF CONTENTS 1. INTRODUCTION OBJECTIVES STUDY AREA AND SAMPLE SITES FIGURE 1. A MAP SHOWING THE POTENTIAL SITES IN THE CUITO AND KWANDO RIVERS FOR THE SAREP 2013 BIODIVERSITY SURVEYS TABLE 1. COLLECTION SITES FOR THE SAREP ANGOLA FIELD TRIP (6-26 TH MAY 2012).. 2 FIGURE 2. A MAP SHOWING THE SAMPLING SITES ON THE CUITO AND OKAVANGO RIVERS DURING THE SAREP ANGOLAN (OKAVANGO) FIELD TRIP (13-30 TH MAY 2013) FIGURE 3. A MAP SHOWING THE SAMPLING SITES ON THE KWANDO RIVER DURING THE SAREP ANGOLAN (OKAVANGO) FIELD TRIP (13-30 TH MAY 2013) FIGURE 4. SELECTED COLLECTION SITES DURING THE SAREP ANGOLAN (OKAVANGO) FIELD TRIP (13-30 TH MAY 2013) METHODS RESULTS FISH CATCH DATA TABLE 2. FISH COLLECTIONS SUMMARY FOR ANGOLAN (OKAVANGO) FIELD TRIP (6-26 TH MAY 2012) COMPARISONS BETWEEN 2012 UPPER CUBANGO-CUITO AND 2013 CUITO-KWANDO EXPEDITION COLLECTIONSMS TABLE 3. A COMPARATIVE LIST OF FISH SPECIES COLLECTED IN WESTERN CUBANGO SYSTEMS IN 2012 AND IN EASTERN CUITO-KWANDO SYSTEMS IN TABLE 4. A COMPARISON OF NUMBERS OF SPECIMENS AND SPECIES (IN BRACKETS) OF FISH COLLECTED IN WESTERN CUBANGO SYSTEMS IN 2012 AND IN EASTERN CUITO-KWANDO SYSTEMS IN COMMENTS FIGURE 5. APLOCHEILICHTHYS CF. JOHNSTONI 'BROAD-BAND' RB13-ANGOLA B.JPG FIGURE 6. CITHARINE VARIATION FROM THE LOWER CUITO RIVER iii

4 FIGURE 7. LABEOBARBUS CODRINGTONII CUITO RIVER NEAR RITO SITE RB13-ANGOLA9 7696B.JPG FIGURE 8. SYNODONTIS SPECIES COLLECTED DURING THE ANGOLAN (OKAVANGO) FIELD TRIP (6-26 TH MAY APPENDIX 1. COLLECTIONS OF FISHES MADE DURING THE MAY 2013 SURVEY IN ANGOLA, NAMIBIA AND BOTSWANA AKNOWLEDGEMENTS Logistically simply travelling from Grahamstown, RSA to Angola is complicated and difficult. Mounting a scientific collecting expedition into this region is particularly challenging and numerous people are thanked for making this successful. SAREP and in particular Chris Brooks, Simon Byron and Vince Shacks are thanked for arranging the varied and considerable logistical support during the 2013 expedition. Manuel Domingos of INIP helped the fish team throughout the expedition. Collections staff at SAIAB have helped with sorting and curating fish and frog collections on our return and Tuuli Makinen has processed all bar-code samples. iv

5 1. INTRODUCTION 1.1. Objectives. The May 2013 survey is the second visit to the Okavango system in Angola under the coordination of the Southern Africa Regional Environmental Program s (SAREP). The major goal of the surveys is to expand the geographical coverage of baseline biological inventories for the region in order to aid with resource use planning. The survey was a collaborative effort between SAREP and the Angolan Ministry of Environment s Institute of Biodiversity and the Ministry of Agricultures National Institute of Fish Research. The fish survey was undertaken by specialists from the following organizations with the assistance of Angolan counterparts from the stated Ministries: Roger Bills & Nkosinathi Mazungula (fishes) - The Sothern African Institute for Aquatic Biodiversity (SAIAB), Grahamstown, SA; and Francisco Almeida & Manuel Domingos, Instituto Nacional de Investigacao Pesqueira (INIP), Luanda, Angola Study area and sample sites. The northern rivers of the Okavango system in Angola are long, north-south draining rivers of which the major tributaries are the Cubango, Longa-Cuito and Cuando. The Angola highlands represent a poorly know part of the Okavango system and a potentially fascinating region as the environment is very different from that of the lower altitude and gradient system in Namibia and Botswana. In physical character the western Okavango tributaries are similar to many streams in the upper Zambezi in north-western Zambia. In 2012 we explored areas of the north-western systems mostly in the Cubango around Menongue, Cuchi and Huambo. For a more in-depth discussion of the system, maps of the region and 2012 survey areas see Bills et al During this current survey we have explored limited areas of the lower Cuito and lower Kwando rivers in southern Angola close to the Caprivi Strip of Namibia. Sample sites we chosen largely on the basis of logistics e.g. accessibility and our ability to easily sample multiple environments. 1

Figure 1. A map showing the potential sites in the Cuito and Kwando rivers for the SAREP 2013 biodiversity surveys. Table 1. Collection sites for the SAREP Angolan field trip (13-30 th May 2013).

6 Figure 1. A map showing the potential sites in the Cuito and Kwando rivers for the SAREP 2013 biodiversity surveys. Table 1. Collection sites for the SAREP Angolan field trip (13-30 th May 2013). Field # Locality Name Latitude Longitude Date RB13- South East May Angola Okavango - 5km down from Calais ferry 17 52' 20" 19 50' 10" Cuito - Mpupa rapids (old SANDF camp) 17 30' 30" 20 03' 57" Cuito near Mpupa, elephant wallow 17 29' 21" 20 03' 13" Cuito - upper river crossing near Mpupa 17 30' 46" 20 03' 39" Cuito - rocky drift, side channel, Mpupa 17 30' 40" 20 03' 43" Cuito - lower drift, side channel, Mpupa 17 30' 53" 20 03' 51" Cuito - lagoon up from Rito campsite 16 37' 11" 19 03' 04" Cuito - above Rito camp channel, banks 16 37' 30" 19 03' 28" Cuito - Rito campsite main channel 16 37' 24" 19 03' 12" Cuito - swamp on road south of Rito village 16 46' 47" 19 07' 32" Cuito - floodplain drifts near Maue village 16 54' 35" 19 18' 27" Cuito - swampy margins of river, Oschitato 17 02' 55" 19 32' 04" Cuito - maginal lagoon south of Mpupa 17 38' 33" 20 09' 08" Kwando - dry pan near Jamba 17 35' 21" 22 39' 25" Kwando - Jamba camp site 1 pan 17 27' 46" 22 52' 00" Kwando - pan a few kms after Jamba 17 27' 40" 22 54' 42" Kwando - Boa-fe' lagoon, Jamba 17 19' 44" 20 08' 02" Kwando - Jamba camp site ' ' 20" Kwando - Boa-Fe' Flood plain, Jamba 17 28' 03" 23 04' 47" Kwando - Base-Rio camp site 17 34' 23" 23 15' 36" 30 2

7 Figure 2. A map showing the sampling sites on the Cuito and Okavango rivers during the SAREP Angolan (Okavango) field trip (13-30 th May 2013). Figure 3. A map showing the sampling sites on the Kwando River during the SAREP Angolan (Okavango) field trip (13-30 th May 2013). 3

8 Figure 4. Selected collection sites during the SAREP Angolan (Okavango) field trip (13-30 th May 2013). RB13-Angola02 Cuito River at Mpupa. RB13-Angola04 Cuito overflow channel at Mpupa. 4

9 RB13-Angola08 margins of Cuito River above Rito campsite. RB13-Angola12 margins of Cuito River near camp '4'. 5

10 RB13-Angola17 BoaFe lagoon near Jamba. RB13-Angola18 camp 2 near Jamba. 6

11 2. METHODS Site selection and sampling methods follow from the previous survey Bills, I.R., Skelton, P.H. & Almeida, F A survey of the fishes of upper Okavango River system in Angola. SAIAB Investigational Report No. 73, 61pp. 3. RESULTS 3.1. Fish catch data. A summary of the fishes captured at the 20 sampling sites during the Angolan expedition (lower Cuito and Kwando rivers) is given in Table 2. This gives details of the number of sites at which fishes were caught, total numbers of each species caught, size ranges and minimum, maximum and mean percentages of catch compositions. The species are ordered in the frequency of the number of sites they were collected at. Full catch details are given in Appendix 1. Not all species have been identified to species level and some are undescribed and new to science. Table 2. Fish collections summary for the Angolan (Okavango) field trip (6-26 th May 2013). Species Total Total SL (mm) % comp sites number min max min max Mean Pseudocrenilabrus philander Tilapia sparrmanii Aplocheilichthys johnstoni Aplocheilichthys hutereaui Aplocheilichthys katangae Pharyngochromis acuticeps Synodontis nigromaculatus Tilapia ruweti Barbus afrovernayi Hemigrammocharax machadoi Synodontis macrostigma Pollimyrus castelnaui Barbus multilineatus Tilapia rendalli Schilbe intermedius Hemichromis elongatus Aplocheilichthys sp Marcusenius macrolepidotus Barbus thamalakanensis Hemigrammocharax

12 multifasciatus Microctenopoma intermedium Serranochromis angusticeps Clarias theodorae Nannocharax macropterus Hydrocynus vittatus Sargochromis sp Micralestes acutidens Barbus sp Petrocephalus sp Barbus bifrenatus Synodontis sp Barbus eutaenia Serranochromis robustus Parauchenoglanis ngamensis Clarias ngamensis Brycinus lateralis Barbus barnardi Barbus brevidorsalis Rhabdalestes maunensis Zaireichthys sp Labeobarbus codringtonii Chiloglanis fasciatus Coptostomabarbus wittei Oreochromis macrochir Hepsetus cuvieri Barbus paludinosus Opsaridium zambezense Barbus haasianus Barbus fasciolatus Labeo cylindricus Amphilius uranoscopus Ctenopoma multispine Hippopotamyrus sp Sargochromis giardia Serranochromis macrocephalus Oreochromis andersonii Synodontis thamalakanensis Comparisons between 2012 upper Cubango-Cuito and 2013 Cuito-Kwando expedition collections. 8

13 Table 3. A comparative list of fish species collected in the western Cubango systems in 2012 and in eastern Cuito-Kwando systems in Cubango 2013 Cuito, Kwando Amphilius sp. Amphilius uranoscopus Aplocheilichthys cf. hutereaui Aplocheilichthys cf. johnstoni Aplocheilichthys cf. johnstoni 'mesh' Aplocheilichthys cf. johnstonii, sidestripe Aplocheilichthys johnstoni Aplocheilichthys cf. katangae Aplocheilichthys sp. pygmy Barbus afrovernayi Barbus barnardi Barbus barotseensis Barbus bifrenatus Barbus brevidorsalis Barbus eutaenia Barbus eutaenia 'red eye' Barbus eutaenia 'sharp nose' Barbus eutaenia 'thin line' Barbus fasciolatus Barbus haasianus Barbus kerstenii Barbus kessleri Barbus lineomaculatus Barbus mocoensis Barbus multilineatus Barbus paludinosus Barbus poechii Barbus radiatus Barbus sp. Barbus sp. 'qeve' Barbus sp. 'qeve 2' Barbus tangandensis Barbus thamalakaneneis Barbus trimaculatus Barbus unitaeniatus Barbus viviparus Brycinus lateralis Chetia sp. Chiloglanis fasciatus Chiloglanis sp. 1 Chiloglanis sp. 2 Chiloglanis sp. 'kunene' Amphilius uranoscopus Aplocheilichthys hutereaui Aplocheilichthys johnstoni Aplocheilichthys katangae Aplocheilichthys sp. pygmy Barbus afrovernayi Barbus barnardi Barbus bifrenatus Barbus brevidorsalis Barbus eutaenia Barbus fasciolatus Barbus haasianus Barbus multilineatus Barbus paludinosus Barbus radiatus Barbus sp. Barbus thamalakaneneis Brycinus lateralis Chiloglanis fasciatus 9

14 Clarias cf. liocephalus Clarias ngamensis Clarias stappersii Clarias theodorae Cyphomyrus cubangoensis Hemichromis elongatus Hemigrammocharax machadoi Hemigrammocharax multifasciatus Hepsetus cuvieri Hippopotamyrus ansorgii Hippopotamyrus sp. 1 Hippopotamyrus sp. 2 Hydrocynus vittatus Labeo cylindricus Labeo sp. 'pointed head, no red eye' Labeobarbus codringtonii Labeobarbus sp. 'qeve' Marcusenius altisambesi Mastacembelus sp. 'cuele' Mastacembelus frenatus Mastacembelus sp. 'qeve' Micralestes acutidens Micralestes argyrotaenia Micralestes cf. argyrotaenia Microctenopoma intermedium Mormyrus lacerda Nannocharax macropterus Opsaridium zambezense Oreochromis andersonii Oreochromis macrochir Parakneria fortuita Parauchenoglanis ngamensis Petrocephalus sp. 'black spots' Petrocephalus sp. 'cunene' Petrocephalus sp. 'light' Petrocephalus sp. 'qeve' Pharyngochromis acuticeps Pollimyrus castelnaui Pseudocrenilabrus philander Rhabdalestes maunensis Sargochromis sp. Schilbe intermedius Serranochromis angusticeps Clarias ngamensis Clarias stappersii Clarias theodorae Clarias sp. Coptostomabarbus wittei Ctenopoma multispine Hemichromis elongatus Hemigrammocharax machadoi Hemigrammocharax multifasciatus Hemigrammocharax sp. Hepsetus cuvieri Hippopotamyrus sp. Hydrocynus vittatus Labeo cylindricus Labeo sp. Labeobarbus codringtonii Marcusenius altisambesi Micralestes acutidens Microctenopoma intermedium Nannocharax macropterus Opsaridium zambezense Oreochromis andersonii Oreochromis macrochir Parauchenoglanis ngamensis Petrocephalus catostoma Petrocephalus sp. Pharyngochromis acuticeps Pollimyrus castelnaui Pseudocrenilabrus philander Rhabdalestes maunensis Sargochromis giardia Sargochromis sp. Schilbe intermedius Serranochromis angusticeps 10

15 Serranochromis cf. thumbergi Serranochromis cf. macrocephalus Serranochromis robustus Serranochromis sp. 'red spotted' Serranochromis sp. Synodontis leopardinus Synodontis macrostigma Synodontis nigromaculatus Synodontis sp. 1 Synodontis sp. 2 Synodontis thamalakanensis Synodontis vanderwaali Synodontis woosnami Thoracochromis cf. buysi Thoracochromis sp. Tilapia rendalli Tilapia ruweti Tilapia sparrmanii Zaireichthys sp. Zaireichthys sp. 'brown' Zaireichthys sp. 'brown blotch' Zaireichthys sp. 'long barbels, pallid' Serranochromis macrocephalus Serranochromis robustus Serranochromis sp. Synodontis macrostigma Synodontis nigromaculatus Synodontis sp. Synodontis thamalakanensis Tilapia rendalli Tilapia ruweti Tilapia sparrmanii Zaireichthys sp. Table 4. A comparison of numbers of specimens and species (in brackets) of fish collected in the western Cubango systems in 2012 and in eastern Cuito-Kwando systems in Species Number Number Amphiliidae 121 (2) 10 (1) Poeciliidae 419 (7) 1357 (4) Cyprinidae 1777 (32) 263 (16) Alestiidae 333 (4) 236 (4) Mochikidae 253 (12) 162 (5) Clariidae 16 (4) 18 (3) Anabantidae 14 (1) 14 (2) Cichlidae 379 (18) 489 (14) Distichontidae 144 (3) 79 (4) Hepsetidae 5 (1) 3 (1) Mormyridae 272 (11) 44 (5) Claroteidae 18 (1) 7 (1) Schilbeidae 32 (1) 33 (1) Mastacembelidae 20 (3) 0 (0) Kneridae 8 (1) 0 (0) 11

16 4. COMMENTS. Our overall impressions during this second expedition were that the fish fauna of the lower Cuito and Kwando Rivers were more similar to the southerly areas of the system than those sampled in Species collected in the lower the Cuito and Kwando were mostly well known, described species. The rocky and headwater specialists from the upper Cubango collections of 2012 were, for the most part, missing and floodplain specialists from several families dominated catches. There were a few species of particular interest and notes on these follow. Tables 3 and 4 compare collections from the two expeditions. Obvious differences in the faunas of the two regions are the massive increase in poeciliid topminnows and the decrease in cyprinids and mormyrids in the lower systems. There was overall greater diversity in most groups in the upper river although in many instances species numbers were extremely low. Certain families e.g. kneriids, mastacembelids were absent from our lower river collections and many species e.g. Barbus were absent from the lower river (see table 3). Some absences from catches are probably attributable to sampling techniques and efforts as species are widespread within the system e.g. Mormyrus, some Barbus spp. Bar-coding. At present we have not sent the 2013 materials off for bar-coding (CO1 gene) as we did for the 2012 collections. The samples are being prepared now and should be completed by the end of 2013 and compared with upper river samples. The interest here is to see if there is any genetic structuring in fish population in the greater Okavango system that would indicate barriers to fish movements. Poeciliids. There were fewer species of topminnows in the lower rivers but considerably higher numbers and they dominated most collections. Of special taxonomic interest was the Aplocheilichthys cf. johnstoni species with the broad horizontal pigment band. This is not present in the Okavango in Namibia or Botswana and was abundant in the upper rivers last year. Figure 5. Aplocheilichthys cf. johnstoni 'broad-band' RB13-Angola b.jpg 12

Citharines Distichodontidae. There may be additional species collected in the lower river colour patterns seem to indicate this although it is also possible that there are specific sexual patterns.

Citharine variation from the lower Cuito River. Hemigrammocharax cf machadoi showing variation in pigmentation Probably two different species of Nannocharax cf. macropterus collected near Mpupa.

17 Citharines Distichodontidae. There may be additional species collected in the lower river colour patterns seem to indicate this although it is also possible that there are specific sexual patterns. Bar-coding will hopefully tease this issue out and confirm the number of species present. Overall diversity and abundance was similar to the upper river. Figure 6. Citharine variation from the lower Cuito River. Hemigrammocharax cf machadoi showing variation in pigmentation Probably two different species of Nannocharax cf. macropterus collected near Mpupa. Yellowfishes. Collected last year in the upper river and at two sites in 2013 at Rito and Mpupa camps. Labeobarbus codringtoni occur from the Okavango across to the Kafue and are rare in museum collections. The recent Angolan collections are valuable specimens and will help, with bar-coding, to determine if they are in fact the same species across the upper-zambezian region. Figure 7. Labeobarbus codringtonii Cuito River near Rito site RB13-Angola9 7696b.jpg 13

Sucker-mouth and squeaker catfishes. The identification of all the Synodontis species continues to be a challenge.

Bar-coding will be conducted on all species sampled in an attempt to determine species numbers and identities. Further sampling of these species is essential to sort out their taxomony. Figure 8.

nigromaculatus RB13- Angola02 7275b Synodontis cf. macrostigma RB13-A114 Mpupa 23-04-2013 7999b Artisanal fisheries.

Fishing activity was rarely observed but reports indicated that fishermen were active in floodplain lagoons during our expedition.

18 Sucker-mouth and squeaker catfishes. The identification of all the Synodontis species continues to be a challenge. In general mochokid diversity was lower with fewer Chiloglanis but almost the same species and numbers of Synodontis. The strikingly patterned species of the upper river were present but rare. Bar-coding will be conducted on all species sampled in an attempt to determine species numbers and identities. Further sampling of these species is essential to sort out their taxomony. Figure 8. Synodontis species collected during the Angolan (Okavango) field trip (6-26 th May 2012). Synodontis sp. RB13-Angola b Synodontis sp. RB13-Angola b Synodontis cf. nigromaculatus RB13- Angola b Synodontis cf. macrostigma RB13-A114 Mpupa b Artisanal fisheries. As we were focused on biodiversity surveys time did not allow us to search out fishermen. Fishing activity was rarely observed but reports indicated that fishermen were active in floodplain lagoons during our expedition. Evidence of artisanal fishing methods were present in villages but indicated that these were low-intensity and seasonal activities. However, these rivers have low conductivities and outside of flood periods are relatively small, single channel river systems and thus are of limited productivity. It is likely that with increased pressure on fisheries resources due to population growth and easier access to rivers overfishing will occur in the future. This could be exacerbated by varied habitat degradation and pollution. We suggest a dedicated programme is needed to examine the current fishery and to develop a long-term fisheries management plan and that ideally this should be trans-boundary in scope. 14

19 APPENDIX 1. Collections of fishes made during the May 2013 survey in Angola, Namibia and Botswana. Event Number Full Name Count % Composition RB13- Angola per site 01 Tilapia ruweti Amphilius uranoscopus Aplocheilichthys johnstoni Aplocheilichthys katangae Barbus eutaenia Barbus multilineatus Chiloglanis fasciatus Clarias sp. 02 Clarias theodorae Hemichromis elongatus Hydrocynus vittatus 02 Labeo cylindricus Labeo sp Labeobarbus codringtonii Micralestes acutidens Nannocharax macropterus Opsaridium zambezense Petrocephalus sp Pollimyrus castelnaui Pseudocrenilabrus philander Schilbe intermedius Serranochromis robustus 02 Synodontis cf. macrostigma 02 Synodontis macrostigma Synodontis nigromaculatus Synodontis nigromaculatus Tilapia ruweti Zaireichthys sp. 03 Barbus radiatus Barbus thamalakanensis Clarias ngamensis Marcusenius macrolepidotus Pseudocrenilabrus philander Tilapia sparrmanii Aplocheilichthys johnstoni Aplocheilichthys sp. 04 Barbus afrovernayi

20 04 Barbus bifrenatus Barbus radiatus Clarias ngamensis Hepsetus cuvieri Hippopotamyrus sp Hydrocynus vittatus Marcusenius macrolepidotus Oreochromis andersonii Pollimyrus castelnaui Pseudocrenilabrus philander Rhabdalestes maunensis Sargochromis sp Schilbe intermedius Serranochromis angusticeps Synodontis macrostigma Synodontis nigromaculatus Synodontis sp Tilapia ruweti Tilapia sparrmanii Aplocheilichthys johnstoni Aplocheilichthys katangae Barbus afrovernayi Barbus paludinosus Barbus radiatus Barbus sp Clarias ngamensis Clarias theodorae Marcusenius macrolepidotus Nannocharax macropterus Pollimyrus castelnaui Pseudocrenilabrus philander Serranochromis angusticeps Synodontis sp Tilapia sparrmanii Aplocheilichthys johnstoni Barbus afrovernayi Barbus eutaenia Barbus haasianus 06 Barbus radiatus Brycinus lateralis Hemichromis elongatus Hemigrammocharax machadoi 06 Marcusenius macrolepidotus Micralestes acutidens

21 06 Petrocephalus sp Pharyngochromis acuticeps Pseudocrenilabrus philander Sargochromis sp Schilbe intermedius Serranochromis angusticeps Tilapia rendalli Tilapia sparrmanii Aplocheilichthys hutereaui Aplocheilichthys johnstoni Hemigrammocharax machadoi Aplocheilichthys johnstoni Aplocheilichthys katangae Barbus sp Chiloglanis fasciatus Clarias stappersii Clarias theodorae Hemichromis elongatus Hemigrammocharax machadoi Hemigrammocharax multifasciatus Marcusenius macrolepidotus Microctenopoma intermedium Nannocharax macropterus Petrocephalus catostoma Pharyngochromis acuticeps Pollimyrus castelnaui Pseudocrenilabrus philander Synodontis macrostigma Tilapia sparrmanii Zaireichthys sp. 09 Aplocheilichthys hutereaui Aplocheilichthys johnstoni Aplocheilichthys katangae Aplocheilichthys sp Barbus afrovernayi Barbus multilineatus Barbus radiatus Barbus sp Clarias theodorae Hemichromis elongatus Hemigrammocharax machadoi Hemigrammocharax multifasciatus Hemigrammocharax sp

22 09 Hydrocynus vittatus Hydrocynus vittatus Labeobarbus codringtonii Labeobarbus codringtonii Micralestes acutidens Microctenopoma intermedium Nannocharax macropterus Opsaridium zambezense Pharyngochromis acuticeps Pollimyrus castelnaui Pseudocrenilabrus philander Schilbe intermedius Serranochromis macrocephalus Synodontis macrostigma Synodontis nigromaculatus Synodontis nigromaculatus Tilapia rendalli Tilapia sparrmanii Zaireichthys sp Aplocheilichthys johnstoni Barbus multilineatus Barbus paludinosus Barbus thamalakanensis Ctenopoma multispine Microctenopoma intermedium Pseudocrenilabrus philander Aplocheilichthys hutereaui Aplocheilichthys katangae Aplocheilichthys sp Barbus bifrenatus Barbus brevidorsalis Barbus multilineatus Barbus radiatus Barbus thamalakanensis Coptostomabarbus wittei Pollimyrus castelnaui Pseudocrenilabrus philander Serranochromis robustus Tilapia rendalli Tilapia sparrmanii Aplocheilichthys hutereaui Aplocheilichthys johnstoni Aplocheilichthys katangae

23 12 Barbus eutaenia Barbus fasciolatus Hemichromis elongatus Hemigrammocharax machadoi Hemigrammocharax multifasciatus Hydrocynus vittatus Micralestes acutidens Nannocharax macropterus Oreochromis macrochir Parauchenoglanis ngamensis Pharyngochromis acuticeps Pseudocrenilabrus philander Sargochromis giardi Sargochromis sp Schilbe intermedius Serranochromis angusticeps Serranochromis robustus Serranochromis sp Synodontis macrostigma Synodontis nigromaculatus Synodontis sp Tilapia rendalli Tilapia ruweti Tilapia sparrmanii Aplocheilichthys hutereaui Barbus afrovernayi Barbus brevidorsalis Barbus multilineatus Pseudocrenilabrus philander Tilapia ruweti Aplocheilichthys hutereaui Aplocheilichthys katangae Hepsetus cuvieri Microctenopoma intermedium Oreochromis macrochir Pharyngochromis acuticeps Pseudocrenilabrus philander Tilapia rendalli Tilapia sparrmanii Aplocheilichthys hutereaui Aplocheilichthys katangae Aplocheilichthys sp Aplocheilichthys sp

24 18 Barbus afrovernayi Barbus barnardi Barbus bifrenatus Barbus brevidorsalis 18 Barbus eutaenia Barbus fasciolatus Barbus multilineatus Barbus thamalakaneneis Clarias theodorae Hemichromis elongatus Hemigrammocharax machadoi Hemigrammocharax multifasciatus Microctenopoma intermedium Parauchenoglanis ngamensis Pharyngochromis acuticeps Pollimyrus castelnaui Pseudocrenilabrus philander Rhabdalestes maunensis Sargochromis sp Schilbe intermedius Serranochromis angusticeps Synodontis macrostigma Synodontis nigromaculatus Synodontis thamalakanensis Tilapia ruweti Tilapia sp. 18 Tilapia sparrmanii Aplocheilichthys hutereaui Aplocheilichthys johnstoni Barbus afrovernayi Barbus barnardi Barbus bifrenatus Barbus sp Barbus thamalakaneneis Brycinus lateralis Pharyngochromis acuticeps Pseudocrenilabrus philander Serranochromis robustus Tilapia rendalli Tilapia ruweti Tilapia sparrmanii Aplocheilichthys hutereaui Aplocheilichthys johnstoni Aplocheilichthys katangae

25 20 Barbus barnardi Barbus haasianus Barbus multilineatus 20 Barbus radiatus Barbus thamalakanensis Brycinus lateralis Coptostomabarbus wittei Hemichromis elongatus Hemigrammocharax machadoi Hemigrammocharax multifasciatus Hemigrammocharax sp Parauchenoglanis ngamensis Parauchenoglanis ngamensis Petrocephalus sp Pharyngochromis acuticeps Pseudocrenilabrus philander Rhabdalestes maunensis Sargochromis sp Schilbe intermedius Synodontis nigromaculatus Synodontis sp Tilapia rendalli Tilapia sparrmanii

Fish response to the annual flooding regime in the Kavango River along the Angola/Namibian border

South African Journal of Marine Science ISSN: 0257-7615 (Print) (Online) Journal homepage: http://www.tandfonline.com/loi/tams19 Fish response to the annual flooding regime in the Kavango River along the