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The non-Haplochromis sh fauna in Uganda: an update on
the distribution and a review of data gaps
Dorothy Akoth
Makerere University
Vianny Natugonza ( viannynatugonza@yahoo.com )
Busitema University Maritime Institute
Jackson Etre
Makerere University
Fredrick Jones Muyodi
Makerere University
Laban Musinguzi
Makerere University
Research Article
Keywords: AOO, EOO, habitat degradation, Red List assessment, non-Haplochromis shes
Posted Date: January 23rd, 2023
DOI: https://doi.org/10.21203/rs.3.rs-2199333/v2
License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License
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Abstract
Freshwater shes are the second most threatened group of vertebrates after amphibians. In most developing countries,
the conservation of freshwater shes is largely hampered by limited information and data. The Red List assessments by
the International Union for Conservation of Nature (IUCN) provide a benchmark for conservation and planning, but these
assessments require,
inter alia
, quantitative information on the species range in the wild. This information is largely
missing for many species that face extinction threats. In this paper, we combined species occurrence data, expert
knowledge, and literature to review and update the distribution of non-
Haplochromis
sh species native to Uganda and
determine their geographical extent relative to the global range. Results showed that (i) at least 110 non-
Haplochromis
species occur in Uganda, (ii) the current status in the entire native range for more than 60% of these species is unknown;
(iii) ve species previously known to occur in Uganda:
Amphilius kivuensis, Bagrus degeni, Marcusenius macrolepidotus,
Petrocephalus catostoma
, and
Lacustricola pumilus
lack a native locus and hence not Ugandan shes, (iv) 17 species
occur in areas beyond their previously known range, and therefore, their presence needs further investigations, preferably
by examining specimen collections, and (v) majority of the non-
Haplochromis
species native to Uganda have a wide
distribution outside the national boundaries. We anticipate this information to be relevant both for the national and
global IUCN Red List assessments for the non-
Haplochromis
shes in Uganda. Furthermore, the identied data gaps will
be relevant in prioritizing limited resources during surveys and collections.
Introduction
Freshwater shes are the second most threatened group of vertebrates after amphibians (Darwall & Freyhof, 2016). The
threat level is likely to worsen in future as demand for aquatic food and animal protein continues to increase. Efforts by
governments globally to reduce biodiversity loss have not prevented many habitats and their associated freshwater sh
species from being lost or degraded at an alarming rate (Dudgeon et al., 2006; Darwall et al., 2018). Moreover, sh
species are also being overexploited due to the perception that they are renewable ‘agricultural products’ with no intrinsic
biodiversity value (Wadewitz, 2011). Furthermore, native sheries have been greatly impacted by invasive species
through predation, competition and habitat alteration (e.g., Ogutu-Ohwayo, 1990; Kaufman, 1992)
Conservation of freshwater shes is partly being hampered by limited information and data that are needed to guide
conservation planning.
Ex-situ
conservation, for instance, requires information on their current status in the wild and the
condition of the natural habitat. This information is largely missing for many species that face extinction risk. For
instance, on the International Union for Conservation of Nature (IUCN) Red List database of threatened species, which is
the world’s widest benchmark for conservation and development planning processes (Hoffmann et al., 2008), the
majority of the freshwater sh species remain unassessed due to lack of data (IUCN, 2017).
Uganda is endowed with freshwater sh species diversity: up to 18% of the surface area is covered by lakes, rivers and
swamps, where over 500 sh species dwell (Natugonza & Musinguzi 2022). There are ve major lake basins in Uganda
that lie in two ichthyofaunal provinces, i.e., Victoria, Kyoga, and Edward systems (East Coast Ichthyofaunal province) and
Albert system (Nilo-Sudan Ichthyofaunal province) (Fig.1, Decru et al., 2019). In addition, there are about 160 small lakes
and numerous rivers. These lakes and rivers harbor a great diversity of shes, which are largely endemic (Greenwood,
1966).
To date, Greenwood (1966) is still the most widely used reference for the distribution of non-
Haplochromis
shes in
Uganda. In total, 94 non-
Haplochromis
sh species in 17 families are documented in Greenwood (1966). Yet, taxonomic
discoveries as well as revisions of previously described species have been on the rise since the work of Greenwood
(1966). For example, between 2003 and 2022, approximately 250 new sh species were described globally per year
(Fricke et al., 2022a). This observation suggests that new sh species description is a remarkably active area of species
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discovery, and therefore, Greenwood (1966) is likely out of date, requiring more recent reviews, based on numerous
studies and surveys that have been conducted since then.
Recently, online databases such as FishBase (https://www.shbase.org), the Global Biodiversity Information Facility
(GBIF) (https://www.gbif.org/), and the Freshwater Biodiversity Portal for Uganda (FWB)
(https://freshwaterbiodiversity.go.ug/) have served as key reference tools for more recent data and information.
FishBase is the most comprehensive of these reference tools and has served as an alternative to Greenwood (1966) for
the updates on the shes of Uganda. However, FishBase also has limitations. First, FishBase derives most of the
distributional information on non-
Haplochromis
shes in Uganda from Greenwood (1966). Second, FishBase tends to be
ambiguous when there is no precise information on the species range. For example, a species such as
Garra hindii
(cyprinidae) is documented in FishBase to occur in “Uganda, Kenya, Cameroon, and the Congo basin”; yet,
Garra
species
are mostly endemic (Jos Snoeks,
pers. comm
. 2022), and such a large country distribution, spanning more than four
ichthyofaunal provinces is unlikely. Third, FishBase collates distribution information from published literature, leaving
out enormous information from unpublished surveys and gray literature. Other reference databases such as GBIF and
FWB, which host occurrence data from surveys, require some analytical skills to deduce distributional information, but
these skills are not common with most potential data users such as policymakers.
When precise information on a species’ location is lacking, local conservation planning is greatly affected. Decru et al.
(2020) sought to bridge this information gap by comprehensively reviewing the distribution of non-
Haplochromis
shes
in Uganda, but only focusing on the Lake Edward system. Decru et al., (2020) evaluated the occurrence of the species
found in the Lake Edward system by examining occurrences in three ichthyofaunal provinces: Nilo-Sudan, East Coast
and Congo ichthyofaunal provinces. These authors found that the Lake Edward system alone hosted 34 non-
Haplochromis
species, belonging to 10 families and 21 genera, registering six new species that were not listed by
Greenwood (1966) and the online databases such as FishBase. Similarly, there were several species in Greenwood
(1966) that were no longer valid due to taxonomic revisions. These ndings further underscore the need to review and
update the distribution of shes in other hydrological basins.
Besides, both the online databases (such as FishBase, GBIF, and FWB) and systematic reviews such as Decru et al.
(2020) only provide qualitative information on the species distribution, which is insucient for assessing the
conservation status of the species. The IUCN Red List of Threatened Species, which is the global benchmark for the
conservation status of species, currently relies on quantitative information either on population trends or the
geographical extent to designate a species as threatened or “Least Concern” (IUCN, 2019a). Because information on
population trends is scanty, most assessments in IUCN rely on the geographical extent of the species. The Extent of
Occurrence (EOO) and Area of Occupancy (AOO) are by far the most commonly used metrics to infer the geographical
extent of species used in IUCN assessments (IUCN, 2019a). When estimated at a scale that is biologically relevant to a
species, EOO and AOO can provide insights into the species’ habitat requirements, threats and limitations, and if data are
available over time, valuable trend information (IUCN, 2019a). However, this information is largely missing for many
freshwater species.
The absence of information on EOO and AOO in most studies on species distributions could be one of the reasons most
freshwater sh species have remained unassessed. In Uganda, for instance, 117 non-
Haplochromis
shes were listed on
IUCN website in different Red List categories by the end of 2021. However, the assessments for more than 50% of these
shes were out of date, while an additional 14 species have never been assessed. Because of the recent changes in the
red listing criteria, where quantitative information either by population or geographic extent must be present to designate
a species’ Red List category (IUCN, 2019a), these assessments may never be updated without information on EOO and
AOO.
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The purpose of this study, therefore, is twofold: rst; to review the distribution and occurrence of non-
Haplochromis
shes in Uganda, building on Decru et al. (2020); second, to estimate the extent and range for the non-
Haplochromis
sh
species in Uganda in relation to the global range. This information is needed for updating IUCN Red List assessments as
well as conducting new assessments for the unevaluated species.
Decru et al. (2020) relied on information from literature, distribution notes in Fishbase, museum collections, and eld
expeditions. In this study, eld expeditions and access to museum specimens are not possible. However, occurrence
records in the GBIF and FWB, supplemented by information from FishBase and other literature sources are deemed
sucient to provide a valuable update on the current status of shes in Uganda, which can inform further detailed
investigations and data collection.
Figure 1 shows that sh species native to Uganda live in two major ichthyofaunal provinces: The Nilo-Sudan and the
East-Coast provinces. However, these two ichthyofaunal provinces span many countries, i.e., from the Indian Ocean (East
Africa) to the Atlantic Ocean (West Africa) to the Mediterranean Sea (North Africa). This large extent suggests that shes
that are not endemic to a specic waterbody could have a very wide distribution and range (in terms of EOO and AOO).
Consequently, one would expect the proportion of national EOO and AOO to the global range to be substantially smaller
(probably less than 10% for the shes in the bigger Nilo-Sudan ichthyofaunal province, and less than 50% for the shes
in the relatively smaller East Coast ichthyofaunal province). To investigate this hypothesis, one needs to map both global
and national range of every sh species under consideration to estimate the values of EOO and AOO at global and
national levels. This task is cumbersome, but possible and highly recommended (IUCN, 2019a). When complete, this
information is indispensable when conducting national Red List assessments, which have recently become popular
(Brito et al. 2010), but still lacking for the shes in Uganda.
Material And Methods
Study area and scope
In this study, we examined sh species distribution in all waterbodies across Uganda. There are ve major lakes (Victoria,
Kyoga, Albert, Edward and George) and over 160 small lakes spread across the country in six major drainage basins
(Fig.2), covering about 18% of the total country surface area (Nsubuga et al., 2014). Some of the major rivers include the
Nile, Katonga, Kagera, Sio, and Aswa (Fig.2). Decru et al. (2020) evaluated the occurrence of the species found in the
Lake Edward system by examining occurrences in three ichthyofaunal provinces: Nilo-Sudan, East Coast and Congo
ichthyofaunal provinces. Given that most of the remaining water bodies in Uganda are not shared with the Congo
ichthyofaunal province, this study only considered the Nilo-Sudan and East Coast provinces (Fig.1).
In terms of taxonomic coverage, we focused on non-
Haplochromis
sh species that are native to Uganda. Most water
bodies in Uganda contain large assemblages of endemic haplochromine cichlids; however, these shes are largely
understudied and many remain undescribed. Also, morphologically, the identication of
Haplochromis
species is not
obvious, and as a result, data on occurrence is scanty.
Data sources
Without additional eld expeditions and museum collections, this study sought to rely on the approach used by IUCN, by
using distribution maps that display occurrence of a species within its extent, which is based on past observations and
occurrences, knowledge of habitat preferences, and remaining suitable habitats (IUCN, 2019b). This information was
derived from the literature (both published and unpublished), expert knowledge, online databases such as FishBase
(Froese & Pauly, 2022), Eschmeyer’s catalogue of shes (Fricke et al., 2022b), the GBIF (GBIF.org, 2022), the FWB
(Natugonza & Musinguzi, 2022), and institutional archives, especially from the National Fisheries Resources Research
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Institute (NaFIRRI). These distribution maps are useful in identifying priority conservation areas, identifying data gaps,
and informing management decisions (Jetz et al., 2012).
Updating the species list
A preliminary list of non-
Haplochromis
shes in Uganda was downloaded from FishBase, a global online database of
shes, from the country-specic page (https://www.shbase.se/Country/CountryChecklist.php?
showAll=yes&what=list&trpp=50&c_code=800&cpresence=present&sortby=alpha2&ext_CL=on&ext_pic=on&vhabitat=all2
The taxonomic status of the names was checked using the Eschmeyer's Catalog of Fishes (Fricke et al., 2022b), which is
also an on-line database that references work on the scientic names of sh species and genera.
Fish species occurrence data were downloaded from the GBIF (ltered by country) (GBIF.org, 2022) and the FWB. Data
from these databases follow Darwin Core attributes, which facilitate easy use (Wieczorek et al., 2012). Therefore, all the
occurrence data acquired from non-standard Darwin Core formats such as those of NaFIRRI archives was rst mobilized
into similar formats. These records were rigorously compared with the species list from FishBase to identify any
inconsistencies in the distribution of known species and to ascertain where new species may have been recorded in
recent surveys. Also, the records were checked against a host of literature sources, especially FishBase (Froese & Pauly,
2022), Eschmeyer’s catalogue of shes (Fricke et al., 2022b), Greenwood (1966), and Decru et al. (2020) for
inconsistencies in taxonomy as well as taxonomic updates, uncertainty over the identity or authenticity of the records,
and the accuracy of the locations. Whenever the distribution of a species was in doubt, appropriate species occurrence
designation was applied following the IUCN standard attributes for spatial data (Table1).
Table 1
IUCN standard attributes for spatial data. Adopted from IUCN (2019a). Only extant ranges are used in the estimation of
EOO and AOO.
Code Presence Denition
1 Extant The species is known or thought very likely to occur presently in the area, which encompasses
localities with current or recent (last 20–30 years) records where suitable habitat at appropriate
altitudes remains.
2 Probably
Extant Phased out.
3 Possibly
Extant There is no record of the species in the area, but the species may possibly occur, based on the
distribution of potentially suitable habitat at appropriate altitudes, or the records exist but are
more than 30 years old and the present status cannot easily be ascertained. Identifying
Possibly Extant areas is useful to ag up areas where the taxon should be searched for.
4 Possibly
Extinct The species was formerly known or thought very likely to occur in the area (post 1500 AD), but it
is most likely now extirpated from the area due to habitat loss and/or other threats, and there
have been no conrmed recent records despite searches.
5 Extinct The species was formerly known or thought very likely to occur in the area (post 1500 AD), but it
has been conrmed that the species no longer occurs because exhaustive searches have failed
to produce recent records, and the intensity and timing of threats could plausibly have
extirpated the taxon.
6 Presence
Uncertain A record exists of the species' presence in the area, but this record requires verication or is
rendered questionable owing to uncertainty over the identity or authenticity of the record, or the
accuracy of the location.
Before use, occurrence data was cleaned to make it t for purpose by removing or correcting inaccurate, unreasonable, or
incomplete data (García-Roselló et al., 2014). These included records with localities that were not in Uganda and all the
records without specic epithets. Fields with data that were not relevant to the study were deleted to simplify data
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cleaning. Occurrences that had no coordinates were georeferenced where possible, based on information in the recorded
eld notes, locality, waterbody, and location remarks, using Google Earth Pro. These coordinates were in decimal degrees.
Other occurrence data obtained from the institution archives were mobilized following the Darwin core attributes, where
higher taxonomy for taxa in the data was generated using the GBIF species name matching tool
(https://www.gbif.org/tools/species-lookup). This tool is used to normalize species names from a .
csv
le against the
GBIF backbone. Canadensys coordinate conversion tool (http://data.canadensys.net/tools/coordinates) was used to
convert the geographic coordinates from other formats to decimal degrees.
All the occurrence datasets were changed from GBIF standards to IUCN standards using IUCN standard attributes for
spatial data, which contain the core and optional elds (IUCN 2019a). The core elds are the required or recommended
attributes such as binomial, origin, presence, compiler, citation and year compiled, whereas the optional elds are
attributes that may or may not be included in the dataset such as record number, recorder, country code, verbatim
Latitude and verbatim Longitude. Among the core spatial elds, species presence is the most important attribute as it
determines whether the species range can be quantitatively ascertained or not (IUCN, 2019a). This attribute has ve
elds (Table1), but only three elds were used: ‘extant’, ‘possibly extant’, and ‘presence uncertain’. Most of the species
had occurrence records, but these records were too old to ascertain the present status of the species in the area (i.e., more
than 30 years). These species with older records were presumed possibly extant on assumption that not enough eld
searches for these species have been done (Snoeks,
pers. Comm.
2022). Other shes had records that extended beyond
their known and expected range, based on various literature sources listed above. These shes were designated as
presence uncertain (Table1) until specimens are obtained to conrm their validity. For the attributes such as presence,
origin, seasonal and basis of the record, records were lled in using IUCN lookup codes (Table1; IUCN, 2019a). The codes
for the origin of each taxon were recorded based on information from FishBase (Froese & Pauly, 2022), Greenwood
(1966), and Decru et al. (2020).
Modelling the species range
An updated species list (Table2) was sent to the IUCN Freshwater Unit to create a Species Information Service (SIS)
account. The SIS is the central database used by IUCN to store and manage species accounts and assessments for
publication on the IUCN Red List database. In SIS, a new working dataset was created, comprising all the sh species to
be mapped. Creation of the SIS account enabled access to the IUCN Freshwater Mapping Application (FWMA) used for
mapping species distributions and calculating EOO and AOO (IUCN 2019b). FWMA is a web-based mapping application
that is widely used, as part of assessments for the IUCN Red List of Threatened Species, to produce distribution maps of
freshwater species based on hydro-basin layers (Lehner & Grill, 2013; IUCN, 2019b). This application also provides an
online platform to produce new distribution maps or update existing distribution maps for species published on the IUCN
Red List.
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Table 2
National distribution and range—Extent of occurrence (EOO) and Area of occupancy (AOO)—of selected sh species in
relation to global occurrence.
Species Distribution National
EOO Percentage
of global
(%)
National
AOO
Percentage
of global
(%)
Alestidae
Alestes baremoze
Lake Albert, Murchison and
lower Victoria Niles, and
River Aswa. Possibly extant
Albert Nile and auent of
Lake Albert.
12971.29 1–5 4785 1–5
A. dentex
Lake Albert and Murchison
Nile. Possibly extant in
Albert Nile and some
auent rivers of Lake
Albert
6170.48 1–5 3738 1–5
Brycinus macrolepidotus
Lake Albert and Murchison
Nile; possibly extant Albert
Nile and Aswa river
7385.69 1–5 4036 1–5
B. jacksonii
Lakes Victoria and Kyoga
basins 179992.85 46.8 92275 42.9
B. nurse
Lake Albert and Murchison
Nile; possibly Albert Nile
and Aswa river
11498.31 86.3 4346 57.9
B. sadleri
Lakes Victoria and Kyoga
basins; possibly Aswa river
basin
173974.66 28.6 87080 57.3
Hydrocynus forskahlii
Lake Albert and Murchison
Nile. Possibly extant in
Albert Nile.
6170.48 1–5 3738 1–5
H. vittatus
Lake Albert, Murchison and
Albert Niles. There are no
recent records, but the
species is possibly extant
(Wandera & Balirwa, 2010)
Amphiliidae
Amphilius jacksonii
Lake Edward drainage;
possibly Kagera river
drainage within Lake
Victoria basin. Uncertain in
Kyoga drainage as records
are likely to be of
Amphilius
lujani
(Froese & Pauly,
2022). Also uncertain in the
Southern parts of Lake
Albert.
28366.754 41.3 18992 71.1
A.lujani
Kyoga drainage and
northeastern auent rivers
of Lake Victoria (Thomson
et al., 2015).
7197.66 > 70 4212 > 70
A.
cf.
kivuensis
Lake Edward system (Decru
et al., 2020)
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Species Distribution National
EOO Percentage
of global
(%)
National
AOO
Percentage
of global
(%)
A. sp. “Bwindi”
Lake Edward system (Decru
et al., 2020)
Zaireichthys rotundiceps
Lakes Victoria, Edward, and
Kyoga basins (both in rivers
and lakes) (Decru et al.,
2020; Seegers et al., 2003)
185801.45 12.6 93608 21
Anabantidae
Microctenopoma damasi
Auent rivers of the Lake
Edward system and the
Semliki River, but has not
been found in other
auents of the Lake Albert
system (Decru et al., 2020)
94054.08 62.6 52703 58.02
Ctenopoma muriei
Lakes Victoria, Kyoga,
Edward and Albert and their
auent rivers
213697.27 6.2 161496 25.7
Bagridae
Bagrus bajad
Lake Albert and Muzizi river
mouth, Murchison and
lower Victoria Niles, and
River Aswa. Possibly extant
in Albert Nile.
19000.97 1–5 5004 1–5
Bagrus docmak
Lakes Victoria, Victoria Nile,
Kyoga, Nabugabo, Albert
(including Albert and
Murchison Niles), Edward
and George, Kazinga
channel, Bisina, and River
Kagera
188858.98 1.2 49884 3.4
Cichlidae
Astatoreochromis alluaudi
Victoria, Kyoga and Edward
lake basins, including
Semuliki river (but not
reaching Lake Albert)
185255.024 42.5 122648 40.5
Oreochromis leucostictus
Lakes Edward, George and
Albert, and auent rivers
and streams of these lakes
and of the Semliki River;
introduced in Lakes Victoria
and Kyoga basins
136067.44 70.5 75667 64.6
Oreochromis niloticus
Lakes Edward, George and
Albert, and many crater
lakes in Western Uganda.
Introduced in many
localities in Lakes Victoria
and Kyoga basins. Possibly
in Aswa river basin, but
origin is uncertain.
130223.68 < 1 86141 < 1
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Species Distribution National
EOO Percentage
of global
(%)
National
AOO
Percentage
of global
(%)
Oreochromis esculentus
Lakes Victoria and Kyoga
basins. Virtually extirpated
in the main lakes, but still
present in satellite lakes of
these basins
109909.25 40.8 80211 37.9
Oreochromis variabilis
Lakes Victoria and Kyoga
basins, and River Ayago.
Virtually extirpated in the
main lakes, but still present
in satellite lakes of these
basins
156277.9 49.1 109234 43.8
Coptodon zillii
Lake Albert and the Nile
river; introduced in Lakes
Victoria and Kyoga basins
6170.48 1–5 3738 1–5
Sarotherodon galilaeus
Lake Albert, including the
delta of Murchison Nile 6170.48 < 1 3738 < 1
Pseudocrenilabrusmulticolor
All major lake basins in
Uganda. The current status
in Albert Nile basin is not
known as there no recent
records, but is possibly
extant
224076.37 46.9 188437 45.7
Citharinidae
Citharinus citharus
Lake Albert and Murchison.
Possibly extant in Albert
Nile.
6170.48 1–5 3738 1–5
Citharinus latus
Lake Albert, including the
Delta of Murchison Nile 6171.48 < 1 3739 < 1
Clariidae
Clariallabes petricola
Lake Victoria and Victoria
Nile, and Lake Kyoga. The
current status is unknown
due to lack of recent data,
but possibly extant
Clarias werneri
Lakes Victoria, Kyoga,
Edward, Albert basins 49928.89 30–40 21788 30–40
Xenoclarias eupogon
Endemic to Lake Victoria
(deep waters)
Clarias liocephalus
Widespread in all major
and minor water systems in
Uganda
249945.519 5–10 161436 18.3
Clariasalluaudi
Widespread in all major
and minor water systems in
Uganda, excluding the
Albert drainage
196065.03 30–40 163468 30–40
Clarias gariepinus
Widespread in all major
and minor water systems in
Uganda
267697.37 < 1 217946 5.0
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Species Distribution National
EOO Percentage
of global
(%)
National
AOO
Percentage
of global
(%)
Heterobranchus longilis
Lake Edward and
Murchison Nile
Claroteidae
Auchenoglanis occidentalis
Lake Albert and Murchison
and auent of Lake Kyoga.
Possibly Albert Nile and
Nile basin.
44464.78 1–5 4443 1–5
Cyprinidae
Labeo horie
Drainage basin of Nile river
and Lake Kyoga, including
Aswa river
11498.31 86.3 4346 57.9
Labeo victorianus
Lakes Victoria and Kyoga
basins, both in lakes and
rivers.
143376.75 37 82282 40
Labeo coubie
Lakes Albert and
Murchison Nile; possibly
Albert Nile drainage.
Uncertain in Lake Victoria
as it extends outside the
known native range shown
in Greenwood (1966)
9973.85 1–5 4814 1–5
Labeobarbus ruwenzorii
Rwenzoria area in the upper
Lake Edward system
(Sibwe, Mubuku, Rwimi).
Current status is not known
due to lack of data, but
possibly extant. Uncertain
in the lower Edward system
(Ihihizo, Ishasha rivers in
Bwindi Impenetrable
National Park) (Decru et al.,
2020).
Labeobarbus altianalis
Lakes Victoria, Edward, and
Kyoga basins (both in rivers
and lakes)
185834.97 39.1 101099 41.3
Labeobarbus bynni
Lake Albert and Murchison
Nile. Possibly extant in
Albert Nile.
11498.31 1–5 4346 14
Labeo forskalii
Lake Edward and Albert
drainage systems, and
Aswa river
57738 76.1 24489 63.5
Labeobarbus alluaudi
Lake Edward system
(Rivers Mubuku and Sibwe,
and Ruimi), but it has not
been observed recently.
Page 11/26
Species Distribution National
EOO Percentage
of global
(%)
National
AOO
Percentage
of global
(%)
Labeobarbus huloti
Lake Albert, but there is
insucient information on
distribution as it only
known from the type
locality (Zega on the Vuda
River)
Labeobarbus somereni
Rwenzori area (Sibwe,
Mubuku, Rwimi, and
Kirimia Rivers). No recent
records from these areas,
which could be attributed to
limited sampling of the
area (Decru et al., 2020).
Enteromius Pellegrini
Lake Edward basin 25708.9 58.1 18818 55.3
Enteromius nyanzae
Lake Victoria basin. Current
status unknown due to lack
of recent data. Records
from Lake Kawi are
uncertain and likely to be
misidentication
Enteromiusjacksoni
Lake Victoria and Kyoga
basins 74350.487 10–20 38182 10–20
Enteromiusprofundus
Endemic to Lake Victoria
(Tweddle et al., 2006).
Occurrence records from
Lake Kyoga basin are
uncertain and likely to be
misidentications
33755.071 38.4 29454 58.7
Enteromius alberti
Lakes Edward and George
and their auent rivers;
possibly in auent rivers of
Lake Victoria. Presence in
Albert drainage is uncertain
and needs conrmation
25708.9 18818
Enteromius radiatus
Lake Victoria basin.
Possibly Aswa River basin.
Records from Lake Kyoga
basin are uncertain
44313.81 5–10 20384 5–10
Enteromius sexradiatus
Lake Victoria (possibly in
nearshore).
Enteromius yongei
Aswa river and Lake Kyoga
auent (Greenwood, 1966)
and auent of Lake
Victoria in the North East
(Whitehead, 1960). There
are no recent records, but
the species is possibly
extant
Enteromiuspaludinosus
Lakes Victoria and Kyoga
basins 157218.71 1.7 95592 3.4
Page 12/26
Species Distribution National
EOO Percentage
of global
(%)
National
AOO
Percentage
of global
(%)
Enteromius apleurogramma
Aswa River, Lake Victoria
basin, Lake Edward-George
system, and Lake Kyoga
basin. Presence in Lake
Albert system is uncertain
as it is outside the known
native range
185834.97 5–10 110258 5–10
Enteromius kerstenii
Lakes Victoria, Kyoga,
Edward-George basins.
Presence in Lake Albert
system is uncertain as it is
outside the known native
range
Enteromius magdalenae
Lakes Victoria and
Nabugabo. Current status
unknown due to lack of
recent data. Records from
Lake Kyoga basin are
uncertain and could be
misidentications
Enteromius neumayeri
Lakes Victoria and Kyoga
basin. Possibly extant in
Lake Albert watershed
(Greenwood, 1966).
Records from Lake Edward
system are uncertain as
they are likely to be
Enteromis pellegrin
(Decru
et al., 2020).
157218.71 10–20 93083 10–20
Enteromius perince
Lake Albert, and Aswa River
systems. There are no
recent records, but the
species is possibly extant
(Greewood, 1966).
Garra dembeensis
Lake Victoria and auent
and Victoria Nile 33755.071 < 1 29454 1–5
Danionidae
Rastrineobola argentea
Lakes Victoria and Kyoga
basins 70840.23 35.7 35275 22.6
Engraulicypris bredoi
Lake Albert, including the
delta of Murchison Nile 6170.48 77.16 3738 55.42705
Leptocyprisniloticus
Lake Albert and Murchison
Nile 6170.48 < 1 3738 < 1
Raiamassenegalensis
Aswa river. There are no
recent records, but the
species is possibly extant
(Greenwood, 1966).
Records from Lake Albert
auent are uncertain and
needs verication.
Distichodontidae
Page 13/26
Species Distribution National
EOO Percentage
of global
(%)
National
AOO
Percentage
of global
(%)
Distichodus nefasch
Lake Albert, Murchison Nile,
and Albert Nile. The present
status in Albert Nile needs
to be ascertained with more
recent sampling
5024.97 64.3 3253 49.8
Nannocharaxniloticus
Murchison Nile; also
possibly extant in Lake
Albert and Albert Nile
(Daget & Gosse, 1984)
739.41 70–80 555 70–80
Distichodus rostratus
Murchison Nile; also
possibly extant in Lake
Albert and Albert Nile.
Latidae
Latesmacrophthalmus
Lake Albert, including the
delta of Murchison Nile 6170.48 77.16 3738 55.4
Latesniloticus
Lake Albert, Albert and
Murchison Niles.
Introduced in Victoria Nile,
Lake Victoria and Kyoga
basins
23201.84 < 1 7199 < 1
Malapteruridae
Malapterurus electricus
Lake Albert and auent;
possibly extant in Albert
Nile
26153 < 1 16410 < 1
Mastacembelidae
Mastacembelus frenatus
Lakes Victoria and Kyoga
basins. Possibly extant in
Aswa River. Recent surveys
suggest that the
distribution extends to the
Lower Victoria Nile.
133720.41 1–5 76679 5–10
Mochokidae
Synodontis khartoumensis
Lake Albert and Albert Nile.
Present status unknown
due to lack of recent data
Synodontis victoriae
Lake Victoria and its
auent rivers, Lakes
Nabugabo and Kyoga;
Victoria Nile
100468.542 28.5 22820 18.4
Synodontis afroscheri
Lake Victoria and its
auent rivers, Lake
Nabugabo, Kyoga basin;
Victoria Nile. Records from
the delta of Murchison Nile
are uncertain.
167781.96 31.4 83680 42.6
Page 14/26
Species Distribution National
EOO Percentage
of global
(%)
National
AOO
Percentage
of global
(%)
Synodontis nigrita
Lakes Albert and
Murchison Nile. Possibly
extant in Albert Nile.
Presence in rivers auent
to Lake Albert is uncertain.
9797.807 1–5 6344 1–5
Synodontis schall
Lake Albert and Murchison
Niles. Possibly extant in
Albert Nile and Semiliki
river
11831.394 1–5 7088 1–5
Synodontisfrontosus
Lake Albert and Murchison.
Possibly extant in the Albert
Nile
12677.511 1–5 6904 1–5
Synodontis macrops
Aswa river. Current status
unknown due to lack of
data, but possibly extant
Synodontis serratus
Lake Albert and lower Nile.
It has not been recorded in
the Ugandan side, but the
presence in the DRC side
suggests it possibly occurs
in Uganda (Jos Snoeks,
Pers. Comm
)
Mormyridae
Mormyrus macrocephalus
Lake Kyoga basin; also
possibly extant in Aswa
river (Greenwood, 1966).
75859.84 97.7 56908 98.1
Mormyrus caschive
Lake Albert and the delta of
Murchison Nile; also
possibly extant in Albert
Nile (Greenwood, 1966).
Records in Aswa river and
Elgon region are uncertain.
6170.48 10–20 3738 42.1
Mormyrops anguilloides
Lake Albert and Murchison
Nile (including the delta).
Possibly extant the auent
of Lake Albert and Albert
Nile (Greenwood, 1966).
6170.48 1–5 3738 1–5
Mormyrus kannume
Lakes Victoria, Kyoga,
Albert, George, and Edward.
Not common in most
auent rivers of these
lakes apart from Victoria
and Murchison Niles,
Kagera, and Kazinga
channel.
136849.16 3.7 29659 5.4
Page 15/26
Species Distribution National
EOO Percentage
of global
(%)
National
AOO
Percentage
of global
(%)
Marcusenius cyprinoides
Originally known from
Albert Nile and Aswa river
(Greenwood 1966), but no
recent data to ascertain the
current status. Recent
records suggests the
species is present in Lake
Albert (Wandera & Balirwa,
2010), but this needs
verication
Mormyrus niloticus
Lake Albert, including the
delta of Murchison Nile;
also possibly in the Albert
Nile
6170.48 75–80 3738 55–60
Marcusenius victoriae
Lakes Victoria and Kyoga
basins 119611.164 38.2 75051 41.2
Pollimyruspetherici
Lake Albert and Murchison
Nile; also possibly in Albert
and lower Victoria Nile
6170.48 77.1 3738 55.4
Gnathonemus longibarbis
Lake Victoria and Kagera
system, Victoria Nile and
Lake Kyoga system
180621.83 43.2 91875 42.0
Marcusenius rheni
Lake Victoria. There are no
recent records for this
species
Petrocephalus degeni
Lakes Victoria and Kyoga
basins. This includes all
records previously
identied as
Petrocephalus
catostoma
(Kramer et al.,
2012).
119611.164 50–60 75051 50–60
Pollimyrusnigricans
Lakes Victoria, Nabugabo,
Albert, George, Edward and
Kyoga and auents of the
lakes
154791.29 26.5 56775 18.6
Hippopotamyrus grahami
Lakes Victoria and its
auent rivers, and Kyoga
basin. Possibly extant in
lower Victoria Nile. Records
from Murchison Nile and
River Muzizi (on Lake
Albert) are uncertain and
need verication
143376.75 60–70 82282 670
Hyperopisus bebe
Lake Albert, Albert and
Murchison Niles. Possibly
extant in Aswa river
(Greenwood, 1966)
6170.48 1–5 3738 1–5
Nothobranchiidae
Nothobranchius taeniopygus
Auent of Lake Victoria
and Aswa river drainage
(Greenwood, 1966)
Page 16/26
Species Distribution National
EOO Percentage
of global
(%)
National
AOO
Percentage
of global
(%)
Nothobranchius robustus
Drainage basins of Lake
Victoria and Albert. 145188.97 87.5 77405 > 80
Nothobranchiusugandensis
Drainages of Lakes
Victoria, Albert and Kyoga.
Possibly extant in Aswa
river drainage (Wildekamp,
1995).
781.79 > 80 676 > 80
Nothobranchius elucens
Aringa system, south of
Madi Opei township, Aswa
drainage (Nagy, 2021).
Possibly in other parts of
the Aswa river basin
1760.13 93.5 1550 95.7
Nothobranchius taiti
Apapi river system, Lake
Kyoga basin (Nagy 2019)
Polypteridae
Polypterussenegalus
Lake Albert and auents;
Possibly extant in Albert
Nile and auents
26749.26 1–5 16878 1–5
Procatopodidae
Lacustricola kassenjiensis
Lake Albert, including the
delta of the Semliki River
and the Victoria Nile River
below Murchison Falls.
Lacustricola centralis
Lake Victoria and Kyoga
basins (Wildekamp, 1995;
Seegers, 1997)
143376.75 20.9 82282 28.6
Lacustricola
vitschumbaensis
Lakes Edward and George;
Kazinga Channel, and
auent rivers; northern
parts of Lake Victoria, and
Lake Kyoga drainage
(Wildekamp, 1995; Decru et
al., 2020).
25708.9 29.4 18818 37.3
Lacustricolabukobanus
Lakes Kyoga, George,
Edward, Albert and
adjacent river systems, and
Lake Victoria drainage
147394.5 33.5 98447 35.6
Lacustricola margaritatus
Lakes Victoria and Kyoga
basins (Nagy and Watters,
2022). This includes all
records previously
identied as
Lacustricola
pumilus
.
119611.164 50–60 75051 50–60
Laciris pelagica
Endemic to Lake Edward;
occurrence records in Lake
George are unveried
(hence uncertain)
782.18 29.2 638 24.5
Page 17/26
Species Distribution National
EOO Percentage
of global
(%)
National
AOO
Percentage
of global
(%)
Micropanchax loati
Nile river and the Lake
Victoria system (including
Kyoga and Aswa
drainages) (Wildekemp,
1995).
Platypanchax modestus
Auent rivers of Lakes
Edward and George 29517.86 81.9 16514 88.3
Protopteridae
Protopterus aethiopicus
All major water bodies
(Victoria, Edward, Kyoga,
Albert) and auent rivers.
Possibly extant in Aswa
river basin and Albert Nile
and auent.
213663.73 3.7 160449 16.5
Schilbeidae
Schilbe intermedius
Lakes Victoria (including
Kagera river) and
Nabugabo, Kyoga basin,
Albert and auent;
Murchison and Victoria
Niles; possibly extant in
Aswa river.
202198.44 1–2 108165 1–2
Schilbe mystus
Lakes Albert, Murchison
Nile, and Semliki river.
Possibly extant in Albert
Nile
26284.02 1–5 16420 1–5
The FWMA uses point data on species’ location to create a map, encompassing all possible hydro-basins where a
species can be found. Species were mapped in the FWMA using hydro-basin level 8; after, the EOO, which is the smallest
area that encompasses all the known, inferred or projected sites where a species is extant, was estimated by the
minimum convex polygon method, while the AOO, which is the area inside the EOO occupied by the species, was
estimated using the grid cell method. The two methods are described in detail in IUCN (2019b). Only hydro-basins where
the species was extant (Table1) were used in the estimation of EOO and AOO.
Initially, all mapping was done in the FWMA. The FWMA uses standardized base layers and follows the standard IUCN
methods for mapping freshwater species and automatically calculates EOO and AOO. While the FWMA is quick and
straightforward, it is not possible to complete the maps by connecting hydro-basins without point data (i.e., where the
occurrence of a species is based on expert knowledge of suitable habitat). Connecting hydro-basins without point data is
possible in QGIS, but this approach is cumbersome and time-consuming. Nonetheless, expert users of both tools suggest
that there are advantages to combining the two frameworks: FWMA and QGIS (Laban Musinguzi
pers. Comm
. 2022).
Therefore, we believed that using both tools could help derive the most precise estimates of EOO and AOO. Whenever it
was not possible to complete maps in FWMA, the map shape les were transferred and completed in QGIS. In QGIS, EOO
was estimated as the area of a convex layer encompassing basins where the presence of the species was extant, while
AOO was estimated as the area of the basins where the species was extant. Both FWMA and QGIS are expected to give
comparable estimates of EOO and AOO (IUCN 2019b). All the maps for the species included in this study can be found at
https://freshwaterbiodiversity.go.ug/.
Page 18/26
Results
Fish species diversity and distribution
A review of the 13,656 non-
Haplochromis
occurrence records from GBIF and FWB, combined with literature, resulted in a
total of 110 non-
Haplochromis
sh species belonging to 21 families and 48 genera (Table2). This number includes all
species that were recognized as “extant” and “possibly extant”. Out of this total, 21 species were found only in the rivers
and streams, which is likely to be an underestimate as rivers are not as widely sampled as large lakes, and therefore,
more sampling could reveal more species. Generally, among the major lakes, species richness was highest in Lake
Victoria followed by Albert and least in the Lake Edward system (Fig.3). A total of 12 non-
Haplochromis
shes were
found to be endemic: ve in Lake Victoria; one in Lake Albert; one in Aswa river, two in Lake Edward; and three in the
Rwenzori area (Table2).
Approximately 60% of all shes were recognized as “possibly extant”, either in part or their entire native range (Table2),
as their occurrences were more than 30 years old; these shes were considered “possibly extant” due to the presence of
their native habitats and limited sampling in their native range. Five species previously listed in Uganda:
Amphilius
kivuensis, Bagrus degeni, Marcusenius macrolepidotus, Petrocephalus catostoma
, and
Lacustricola pumilus
have no
native locus; two species previously listed in the Lake Edward system:
Enteromius cercops
and
Enteromius perince
are
not extant in the system; while 17 other species occur in areas beyond their known native range, and therefore, their
presence in those areas, is also uncertain (Table1). A summary of this review is shown below by family.
Amphilidae: One Amphilid species,
Amphilius jacksonii
, was recorded in Uganda by Greenwood (1966), but three other
species have subsequently been recorded:
A. kivuensis
,
A. lujani
, and
Zaireichthys rotundiceps
(Seegers et al., 2003;
Thomson & Page, 2010; Thomson et al., 2015). However, the presence of
A. kivuensis
in Uganda has not been conrmed
e. Morphologically,
A. kivuensis
, which is more of a Congo ichthyofaunal province species, although also reported in
upper Kagera drainage in Rwanda (Froese & Pauly, 2022), shares a close resemblance with
A. uranoscopus
, which is
reported to be widespread in East and Central Africa (Froese and Pauly 2022). Whereas
A. uranoscopus
too has not been
conrmed in Uganda, with its earlier specimens considered in Decru et al. (2020) as
A
. cf.
kivuensis
, in terms of
biogeography, it is closer than
A. kivuensis
, and shes in Uganda previously attributed
A. kivuensis
might turn out to be
A.
uranoscopus
(Decru et al., 2020), but this needs further investigation. Meanwhile, two new possible amphilids from the
Lake Edward system are considered in this study:
A
. sp. Bwindi and
A
. cf.
kivuensis
(Decru et al., 2020), bringing the total
possible number of amphilids in Uganda to ve species
Bagridae: Greenwood (1966) listed only two species under this family:
Bagrus docmak
and
B. bayad
, but also noted the
likelihood of a third species,
Bagrus degeni
, in Lake Victoria, except that it closely resembled
B. docmak
and considered
the two species to be one. Recently, Ferraris (2007) listed
B. degeni
as a distinct species occurring in Lake Victoria, which
was subsequently adopted by FishBase (Froese & Pauly, 2022), but with no new observations or additional specimens.
Given that there is no single record of this species from Lake Victoria apart from the type specimens, and considering the
numerous surveys conducted on the lake, its presence appears questionable and the specimens are likely to be those of
B. docmak.
Cyprinidae: Greenwood (1966) listed several
Enteromius
species under the genus
Barbus
, before it was split into the large
hexaploid barbs in the genus
Labeobarbus
(Vreven et al., 2016) and small diploid barbs in the genus
Enteromius
(Van
Ginneken et al., 2017). This study found that the records from surveys previously attributed to
Enteromius cercops
and
E.
perince
need to be reconciled in line with the recent taxonomic updates. The former was previously recorded in the
auents of Lakes Victoria, Kyoga and Edward (Greenwood, 1966). However, the work of Decru et al. (2020) showed that
records previously attributed to this species in the Lake Edward system were
E. perince
, which were latter re-identied as
Page 19/26
E.
cf.
mimus
, while
E. cercops
was synonymized with
E. alberti
(Maetenes et al., 2020). It is not known whether the
records from Lake Kyoga basin previously attributed to
E. cercops
conform to
E. alberti
.
Mormyridae: Greenwood (1966) recorded 13 species under this family. In this study, we found occurrence records for
species that were doubtful, such as
Marcusenius macrolepidotus
from Lakes Kyoga and Nakuwa. This species has a
native distribution in the Zambezi ichthyofaunal province (Froese & Pauly, 2022). Whereas sh species can be shared by
two ichthyofaunal provinces, as is the case for
Ctenopoma damasi, Pseudocrenilabrus multicolor
, and
Oreochromis
leucostictus
that occur in both the East Coast and Nile-Sudan possibly via River Semiliki (Decru et al., 2020), M.
macrolepidotus
may not be shared with shes in the East Coast province (Kyoga and Nakuwa). Similarly,
Petrocephalus
catostoma
has a native distribution in the Zambezi ichthyofaunal province. It is listed by Greenwood (1966) to occur in
Lake Victoria and Nabugabo and the Victoria Nile (East Coast Ichthyofaunal province), while other occurrence records
from GBIF extend the distribution to Lakes Albert, Kyoga, George, Nabugabo, Kagera, and Nyaguo, which span two
Ichthyofaunal provinces (Fig.1). Such a distribution is not likely for lacustrine species, and therefore, the records in
Uganda can be considered
Petrocephalus degeni
(Kramer et al., 2012).
Procatopodidae: This family represents the riverine killishes, commonly known as the African lampeyes, originally
attributed in old literature to family cyprinidontidae (e.g., Greenwood, 1966). In this family,
Lacustricola pumilus
was
originally (and is still) identied in many surveys as
Aplocheilichthys pumilus.
A revision of the genus
Aplocheilichthys
and its synonymization with the genus
Lacustricola
(Huber, 1999) implies that
A. pumilus
lacks a native locus in Uganda
because
L. pumilus
is endemic to Lake Tanganyika drainage (Froese & Pauly, 2022). In the Lake Edward system, most of
the records previously attributed to
A. pumilus
have been re-identied as
Lacustricola bukobanus
(Decru et al., 2020),
while those in the Lakes Victoria and Kyoga systems have been re-identied as
Lacustricola margaritatus
(Nagy &
Watters, 2022).
Extent and range of the non- Haplochromis species
The estimates of EOO and AOO for the non-
Haplochromis
shes are shown in Table2. Generally, the EOO and AOO for
most species (59) were less than 50% of the global range; in fact, 29 species had EOO and AOO values less than 10% of
the global range implying that most of the species have a relatively wider distribution outside Uganda. According to the
IUCN red listing criterion B, the minimum EOO for a species to trigger extinction threat category is 20,000 km2 (IUCN
2019a). Table2 shows that only 29 sh species (26%) had EOO values less than 20,000 km2. The EOO and AOO for 25
sh species (about 22% of the total non-
Haplochromis
shes) could not be quantitatively ascertained because their
presence was designated as possibly extant, requiring intense surveys to ascertain the current status of these species in
their native habitats.
The family Cichlidae had representatives with the largest geographical extent (e.g.,
Pseudocrenilabrus multicolor
,
Oreochromis leucoustictus
, and
Oreochromis niloticus
), followed by claridae (e.g.,
Clarias gariepinus
) (Table2). Families
with the most restricted range were Citharinidae, Danionidae, and Distichodontidae. These families mostly have
individual species endemic to Lake Albert. Generally, water bodies within the Nilo-Sudan ichthyofaunal province, i.e. Lake
Albert and Murchison Nile had more species with restricted range (e.g.,
Pollimyrus petherici
,
Mormyrus caschive
,
Mormyrops anguilloides, Engraulicypris bredoi, Leptocypris niloticus, Labeo coubie, Citharinus citharus, Citharinus latus,
Alestes dentex, and Hydrocynus forskahlii
) compared to water bodies in the East Coast ichthyofaunal province: i.e.
Edward (e.g.,
Laciris pelagica
) and Aswa drainage (e.g.,
Nothobranchius elucens
).
Discussion
The purpose of this study was to review and update the literature on the distribution and range of non-
Haplochromis
shes in Uganda, building on the recent work by Decru et al. (2020) for the Lake Edward system. Although no new eld
Page 20/26
survey was conducted, this study was possible because of the large amounts of data that have recently been made
available through GBIF and the Freshwater Biodiversity portal for Uganda. This study recorded a total of 110 non-
Haplochromis
species to occur in Uganda in different hydro-basins. This number implies 20 additional species to the
original list by Greenwood (1966), given that four species previously listed by Greenwood (1966) do not have a native
distribution in Uganda. The study also revealed a total of 17 non-
Haplochromis
species that occur within Uganda, but
extending to areas outside their known native range documented in Greenwood (1966), FishBase (Froese & Pauly, 2022),
and Eschmeyer’s catalogue of shes (Fricke et al., 2022b). This nding is not necessarily surprising given the recent
(especially within the last two decades) numerous studies and surveys, which largely remained unpublished until the
work of Natugonza & Musinguzi (2022). Given that these are new records that have not been armed by examination of
their specimens, their occurrence in the new areas is still uncertain. Generally, the specimens for these species from these
new habitats are not available. The NaFIRRI has conducted most of these surveys, but without systematic preservation
of these specimens. This is a huge gap, and a systematic search and collection of specimens from these new habitats
and a follow-up study to conrm this distribution are urgent. This study provides a foundation from which future surveys
and eld expeditions can be prioritized.
In terms of diversity, more species were recorded in large waterbodies or hydro-basins, which is also expected.
Distribution and diversity, among others, are inuenced by the size of the waterbody, surface area of the drainage basin,
and topographical features (Franklin, 2010; Pelayo-Villamil et al., 2015; Trigal & Degerman, 2015). The higher species
richness observed in Lake Victoria, for example, is expected because of its size and habitat heterogeneity, with sh being
able to evolve and adapt to the different habitats. However, it is also important to note that these large waterbodies have
been the major focus for numerous sheries investigations and surveys, with limited attention to small waterbodies such
as swamps, rivers, streams and minor lakes. These small ecosystems have been shown to harbor large assemblages of
sh (Tibihika et al., 2015), and therefore, it is possible that with extended sampling and targeted surveys covering these
systems, more species could be recorded beyond what is listed in this study.
Aside from species diversity, limited investigations on small ecosystems can also be seen in the estimated geographical
range for some species. Table2 shows many species without values of EOO and AOO because these species were
designated as possibly extant due to a lack of recent data. IUCN guidelines for mapping species suggest that a species
should only be designated as ‘extant’ if it has been observed or recorded within the last 30 years (Table1; IUCN 2019a).
Some non-
Haplochromis
species were described from their type localities and have not been recorded since then.
Nevertheless, these shes were designated as possibly extant as sh may not just disappear or move to another area, but
instead, there have not been targeted searches for these species (Jos Snoeks,
pers. comm
. 2022). This delimitation will
have implications for the red listing as these shes whose range could not be quantitatively ascertained can only be
listed as Data Decient (IUCN, 2019a). This means, even with the large amounts of data in GBIF and FWB, more than
50% of non-
Haplochromis
shes are generally still Data Decient. Still, this designation is important as it points
researchers to areas that are in need of data collection (IUCN, 2019a).
The national EOO and AOO for most shes was less than 50% of their global range, a nding that was consistent with
expectation. It was generally expected that since Uganda shares a small portion of both the Nile-Sudan and East Coast
Ichthyofaunal provinces (Fig.1), the proportion of the species’ national range to the global range would be substantially
low. This expectation was consistent with shes especially from the Lake Albert system, i.e., Lake Albert, Murchison and
Albert Nile, which, apart from the few endemic species, shares similar sh fauna with Western and Northern Africa (Nile-
Sudan Ichthyofaunal province). For the East Coast fauna, the proportion of national range to global range partly deviated
from expectation, where majority of the shes had national EOO and AOO greater than 50% of the global range. This
nding was unexpected, but also not entirely surprising because the sh fauna of Lake Victoria resembles that of the
Lakes Kyoga and Edward systems. For instance, all sh families occurring in the Lake Edward system occur in Lake
Victoria, although four families that are native to Lake Victoria (i.e., Alestidae, Mastacembelidae, Mochokidae and
Page 21/26
Schilbeidae) are absent in the Edward system (Decru et al., 2020). The three systems are often collectively referred to as
the Lake Victoria region (e.g., Greenwood, 1966; Natugonza et al., 2021). The connection between Lake Victoria and
Kyoga is clear: the two systems are directly connected by Victoria Nile. However, the connection between Lake Victoria
and the Lake Edward system is not straightforward, although it is suggested that the two systems could be connected
through the marshy areas on the Katonga and Ruizi rivers (Decru et al., 2020). Therefore, the large extent of the Lake
Victoria region, coupled with a high species endemism, may explain why the Ugandan non-
Haplochromis
shes of the
East Coast province have a big national distribution and range approaching the global range.
Conclusion
This study used species occurrence data, integrated with expert knowledge and literature, to review and update the
distribution of non-
Haplochromis
sh species native to Uganda and determine their geographical extent relative to the
global range. The review suggests that (i) at least 110 non-
Haplochromis
species occur in Uganda, (ii) ve non-
Haplochromis
species previously considered to be native to Uganda:
Amphilius kivuensis, Bagrus degeni, Marcusenius
macrolepidotus, Petrocephalus catostoma
, and
Lacustricola pumilus
lack a native locus, while (iii) 17 species occur in
areas beyond their known native range, requiring further investigation to assess their taxonomic correctness, preferably
by examining the specimen collections. This study highlights areas and species that need to be prioritized during surveys
and collections, thereby providing a strong foundation for lling data gaps. The information in this study will also be
useful in updating IUCN Red List assessments as well as conducting new assessments for the unevaluated species. The
geographical restrictedness of the majority of the non-
Haplochromis
species native to systems in the East Coast
ichthyofaunal province underscores the importance of actions to halt degradation of sh habitats and overexploitation,
which pose a faster extinction risk as these shes may have a limited chance to be conserved elsewhere.
Declarations
Acknowledgements
We wish to thank Catherine Sayer and Caroline Pollock of the IUCN Freshwater Biodiversity Unit for their extensive
assistance with the use of the Freshwater Mapping Application (FWMA) tool. This work was done with funding from the
JRS Biodiversity Foundation as part of the M.Sc. Scholarship to the rst author. We also thank the GBIF for additional
funding for data mobilization projects at NaFIRRI.
Ethical Approval
Not applicable.
Competing interests
The authors declare no conicts of interest.
Authors' contributions
Vianny Natugonza and Laban Musinguzi conceived the idea and designed the study; Dorothy Akoth, Vianny Natugonza
and Laban Musinguzi assembled and analysed all the data and generated species distribution maps; Dorothy Akoth,
Vianny Natugonza, Jackson Etre, Fredrick Jones Muyodi, and Laban Musinguzi wrote and revised the manuscript.
Funding
Page 22/26
This project was funded by JRS Biodiversity Foundation through a grant to the National Fisheries Resources Research
Institute (NaFIRRI): Grant Number OPP201806.
Availability of data and materials
All data used here are freely available at GBIF.orghttps://doi.org/10.15468/dl.48xwy3 and Freshwater Biodiversity Data
for Uganda:https://freshwaterbiodiversity.go.ug/. A cleaned dataset is available from the corresponding author upon
request.
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Figures
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Figure 1
Extent of two ichthyofaunal provinces in Africa (left panel) and Uganda (right panel).
Figure 2
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Location of major drainage basins in Uganda, with the major lakes and rivers. Letters denote major basins: A (Victoria), B
(Edward), C (Kyoga), D (Albert), E (Aswa River), F (Albert Nile). Numbers denote major lakes: 1 (Albert), 2 (Kyoga), 3
(Victoria), 4 (Edward), 5 (George). Roman numerals denote major rivers: (i) Upper Victoria Nile, (ii) Murchison Nile, (iii)
Murchison Nile Delta, (iv) Lower Victoria Nile, (v)Aswa, (vi) Kagera, (vii) Katonga, (viii) Sio, (ix) Alber Nile.
Figure 3
Fish species richness in Uganda in different hydro-basins.
