Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 May 2021 | 13(6): 18551–18558
ISSN 0974-7907 (Online) | ISSN 0974-7893
(Print)
https://doi.org/10.11609/jott.6724.13.6.18551-18558
#6724 | Received 20 September 2020 | Final
received 06 November 2020 | Finally accepted 03 May 2021
Discovery of two new populations
of the rare endemic freshwater crab Louisea
yabassi Mvogo Ndongo, von Rintelen & Cumberlidge, 2019 (Brachyura: Potamonautidae) from the Ebo
Forest near Yabassi in Cameroon, Central Africa, with
recommendations for conservation action
Pierre A. Mvogo
Ndongo 1, Thomas von Rintelen
2, Christoph D. Schubart 3, Paul F.
Clark 4, Kristina von Rintelen 5,
Alain Didier Missoup 6, Christian Albrecht
7, Muriel Rabone 8, Efole Ewoukem 9,
Joseph L. Tamesse 10, Minette Tomedi-Tabi Eyango 11 & Neil Cumberlidge
12
1,6,9,11 Département de Gestion des Écosystèmes Aquatiques, Institut des Sciences Halieutiques,
Université de Douala à Yabassi,
PO. Box. 7236 Douala-Bassa, Cameroun.
1,2,5 Museum für
Naturkunde, Leibniz Institute for Evolution and Biodiversity
Science, Invalidenstrasse 43, 10115 Berlin, Germany.
3 Zoology & Evolution,
Universität Regensburg, 93040 Regensburg, Germany.
4,8 Department of Life Sciences, The
Natural History Museum, London, SW7 5BD, UK.
6 Zoology
Unit, Laboratory of Biology and Physiology of Animal Organisms, Faculty of
Science, University of Douala, POBox 24157 Douala,
Cameroon.
7 Department of Animal Ecology
& Systematics, Justus Liebig University, Heinrich-Buff-Ring 26-32 IFZ,
D-35392 Giessen, Germany.
10 Laboratory
of Zoology, Higher Teacher Training College, Department of Biological Sciences,
University of Yaounde I, P.O. Box 47, Yaounde, Cameroon.
11 Département d’Aquaculture,
Institut des Sciences Halieutiques,
Université de Douala à Yabassi,
PO. Box. 7236 Douala-Bassa, Cameroun.
12 Department of Biology, Northern
Michigan University, Marquette, MI, 49855-5376, USA.
1 mpierrearmand@yahoo.fr
(corresponding author), 2 thomas.vonrintelen@mfn.berlin,
3 christoph.schubart@biologie.uni-regensburg.de,
4 p.clark@nhm.ac.uk, 5 kristina.vonrintelen@mfn.berlin, 6 admissoup@ymail.com,
7 christian.albrecht@allzool.bio.uni-giessen.de,
8 m.rabone@nhm.ac.uk, 9 efole_thomas@yahoo.fr,
10 jltamesse@yahoo.fr, 11 tomedi_tabi@yahoo.fr, 12 ncumberl@nmu.edu
Editor: Anonymity requested. Date of publication: 26 May 2021 (online & print)
Citation: Mvogo Ndongo,
P.A., T. von Rintelen, C.D. Schubart,
P.F. Clark, K. von Rintelen, A.D. Missoup,
C. Albrecht, M. Rabone, E. Ewoukem,
J.L. Tamesse, M.
Tomedi-Tabi Eyango
& N. Cumberlidge (2021). Discovery
of two new populations of the rare endemic freshwater crab Louisea yabassi Mvogo Ndongo, von Rintelen & Cumberlidge, 2019 (Brachyura: Potamonautidae) from the Ebo
Forest near Yabassi in Cameroon, Central Africa, with recommendations for
conservation action. Journal of Threatened Taxa 13(6): 18551–18558. https://doi.org/10.11609/jott.6724.13.6.18551-18558
Copyright: © Mvogo Ndongo et
al. 2021. Creative
Commons Attribution 4.0 International License.
JoTT allows unrestricted use, reproduction,
and distribution of this article in any medium by providing adequate credit to
the author(s) and the source of publication.
Funding: We thank the Rufford Small Grant Foundation (ID: 28462-D) for funding the field work in southern and southwestern Cameroon.
Competing interests: The authors declare no competing interests.
Author details: Pierre A. Mvogo Ndongo, Ph.D in Biology (speciality,
Zoology) is interested on taxonomics/systematics,
phylogenetics and conservation of West and Central African freshwater and
mangrove Decapod Crustaceans, as well as sustainable management of the
ecosystems they depend from. He is the Chief of Research unit for taxonomics/systematics, production and sustainable
management of aquatic animals at the Department of Management of Aquatic
Ecosystems, Institute of Fisheries and Aquatic Science, University of Douala,
Cameroon. Thomas von Rintelen is an
evolutionary biologist with a focus on molecular phylogenetics and genomics at
the Museum für Naturkunde,
Berlin, Germany. He is strongly interested in the diversity and biogeography of
tropical freshwater invertebrates and their conservation. Much of his research
is focused on SE Asia, but he is also active in Cameroon. Christoph
D. Schubart works as an Assistant Professor in
the Department of Zoology and Evolutionary Biology at the University of
Regensburg in Germany. investigates the evolution and diversification of
aquatic arthropods (mainly Crustacea). With his study group he investigates the
diversification and speciation history of aquatic arthropods, mainly decapod
Crustacea from marine and freshwater environments. Paul F.
Clark is a decapod crustacean specialist at The Natural History Museum,
London, UK who does research on brachyuran crabs and their larvae. He has a
strong interest in non-native UK species, and he is currently studying
co-endemicity of paragonimiasis with respect to its links with Sub-Saharan
African species of freshwater crabs. Kristina von Rintelen
is a researcher at the Museum für Naturkunde,
Berlin, Germany, specialized on crustaceans, especially freshwater shrimps. She
is particularly interested in the taxonomy and speciation of tropical species
as well as the implementation of integrative taxonomy approaches. Kristina has
also been involved in Red List assessment of freshwater crustaceans. Alain
Didier Missoup is an Associate Professor in
the Zoology Unit of the Laboratory of Biology and Physiology of Animal
Organisms in Faculty of Science, University of Douala. He studies
diversification patterns promoting the biodiversity in tropical Africa and
bushmeat trafficking in Central Africa. He currently works on the fauna of Ebo Forest where the species Louisea
yabassi was rediscovered. Christian
Albrecht is an Associate Professor of Biogeography at Justus Liebig
University Giessen, Germany. He is interested in biodiversity, biogeography,
evolution, and conservation of invertebrates in African freshwater, focusing
mostly on molluscs and crustaceans. Muriel Rabone is a sample coordinator for SCAN
(Schistosomiasis Collection at the Natural History Museum) in London, UK. She
is currently studying the co-endemicity of paragonimiasis and tuberculosis in
Sub-Saharan Africa and she is utilising existing data
to improve public health outcomes. T. Efole Ewoukem is an Associate professor working on fishes
production and conservation of aquatic plants from Cameroon. Joseph
L. Tamesse
is a Professor of Biology working on taxonomics/systematics
and conservation of Central African Invertebrates. Minette
Tomedi-Tabi Eyango,
is a Professor of Aquaculture, with interest on production and aquatic
bio-resources from Southern-Cameroon. She is the active Director of the
Institute of Fisheries and Aquatic Science, University of Douala at Yabassi, near Eboforest,
Cameroon. Neil Cumberlidge is a Professor of
Biology who conducts research on African freshwater crab conservation,
biogeography, systematics and evolution and is the Chair of the Freshwater
Crustacean Specialist Group of the International Union for the Conservation of
Nature. He is an active conservationist who led the global Red Listing of the
freshwater crabs of the world.
Author contributions: Pierre A. Mvogo Ndongo
collected the data, Pierre A. Mvogo Ndongo, Neil Cumberlidge, Thomas
von Rintelen, Christoph Schubart,
Paul Clark, Christian Albrecht, and Muriel Rabone analysed the data and wrote the manuscript. Kristina von Rintelen, Alain Didier Missoup,
Thomas Efole Ewoukem,
Joseph L. Tamesse, and Minette Tomedi
Tabi-Eyango gave valuable inputs in data processing
and made constructive improvements to the manuscript.
Acknowledgements: We thank the Rufford Small Grant Foundation for funding the field work
in southern and southwestern Cameroon.
We are also grateful to Dr. Ekwoge Awe and Mr. Daniel Fossa for their support during
the first fieldtrip to a rainforest of Yabassi (Ebo Forest Zone). Dr. Charles Fransen (Naturalis
Biodiversity Centre, Leiden, The Netherlands), Dr.
Tomoyuki Komai (Natural History Museum and Institute, Chiba, Japan) provided
the first author with constructive advice during the course of the
project.
Abstract: The endemic freshwater crab, Louisea yabassi Mvogo Ndongo, von Rintelen & Cumberlidge, 2019,
is currently only known from three populations in the biodiversity-rich
rainforests of southwestern Cameroon.
The first record of L. yabassi
dates back to 1908 from Yabassi, while the other two
populations were discovered in December 2019 and March 2020 from the Ebo Forest near Yabassi. These specimens were initially identified as L.
edeaensis (Bott,
1969), but were subsequently assigned to L. yabassi. The newly-discovered populations of L.
yabassi provided important data on its
habitat, population structure and geographical distribution, all critical
knowledge for conservation measures.
Reported here are the anthropogenic threats to L. yabassi and its rainforest habitat, which
include forest destruction, agricultural encroachment, water pollution and
firewood collection. This information is
inherently useful in the assessment of the extinction risk of L. yabassi and highlights the importance of
implementing strategies for preserving primary rainforest and its associated
aquatic habitats in Central Africa.
Keywords: Cameroon, Conservation action
plan, diversity, Ebo Forest, freshwater crab, Louisea edeaensis,
L. yabassi, threats, Yabassi.
Résumé : Le crabe d’eau douce, Louisea
yabassi Mvogo Ndongo, von Rintelen & Cumberlidge, 2019, est endémique et exclusivement connu par trois
populations dans les riches forêts
du sud du Cameroun. Il a été
collecté pour la première fois
en 1908 dans la zone de Yabassi, les deux autres populations ont été échantillonnées
en décembre 2019 et mars
2020 dans la forêt d’Ebo près de Yabassi.
Les spécimens, initialement
identifiés comme L. edeaensis (Bott, 1969), ont par la suite été reconnus comme étant des représentants de la
nouvelle espèce L. yabassi.
Les spécimens nouvellement collectés ont fourni
des données importantes sur
l’habitat, la structure des populations et la répartition géographique de L.
yabassi, toutes ces connaissances étant préalables pour décider des mesures de
conservation de l’espèce. Les menaces anthropiques pesant sur L. yabassi sont signalées ici, notamment la destruction des forêts,
les activités agricoles, la
pollution de l’eau et la collecte
du bois de chauffage. Ces informations sont importantes pour l’évaluation du risque d’extinction de L. yabassi et
soulignent l’importance de
la mise en œuvre de stratégies de préservation de la forêt tropicale primaire et de ses habitats aquatiques associés en Afrique
Centrale.
Mots clés: Plan d’action
de conservation, crabe d’eau
douce, Louisea edeaensis, L. yabassi,
menaces, diversité, forêt d’Ebo, Yabassi, Cameroun.
INTRODUCTION
The present
work arises from the discovery of two new populations of Louisea yabassi Mvogo Ndongo, von Rintelen & Cumberlidge, 2019,
from the Ebo Forest near Yabassi
in southwestern Cameroon. This rare
endemic species of freshwater crab is currently known from just three small
populations found in Yabassi (collected in 1908; Cumberlidge 1994b, 1999), and the Ebo
Forest (collected in December 2019 and March 2020; Mvogo
Ndongo et al. 2019).
The Ebo Forest, where L. yabassi
was rediscovered (Figure 1, Image 2), is the largest remaining tract of primary
lowland and submontane rainforest in this part of
Africa, and is drained by the Wouri and Dibamba rivers that flow into the Atlantic Ocean. This forested area represents a key
biodiversity hotspot in southwestern Cameroon for a number of freshwater taxa
including crabs. The freshwater
catchments of the Ebo Forest are important spawning
grounds for fish and invertebrates, and the forest is also a refuge for
charismatic wildlife including monkeys, chimpanzees, gorillas, manatees,
elephants, birds, turtles, snakes, and amphibians (Cumberlidge
1994b, 1999; Morgan & Abwe 2006; Morgan et al. 2013).
The
rediscovery of L. yabassi after over
110 years means that living specimens of this species are now available for
scientific studies that allow for DNA analysis, a description of its habitat,
and ecological and population studies.
The difficult taxonomy and the chronic lack of material in the past
meant that the original specimens from Yabassi were
initially identified as L. edeaensis
(Bott, 1969) by Cumberlidge
(1994a, 1999) and Mvogo Ndongo
et al. (2017a).
Preliminary
surveys indicated that this newly-rediscovered species is facing immediate
threats to its freshwater habitat from forest destruction, agricultural
encroachment, water pollution, and firewood collection. Presented here is the necessary field data
for an IUCN Red List extinction risk assessment of this species including its
specific habitat requirements, population trends, distribution, and threats (Mvogo Ndongo et al. 2017a). The importance of assessing the extinction
risk of L. yabassi is underlined
by the status of two other rare endemic species assigned to Louisea
in southwestern Cameroon, L. edeaensis
(Cumberlidge, 1994) and L. balssi
(Bott, 1969) that are both currently listed as
Endangered species (EN) on the International Union for Conservation of Nature
(IUCN) Red List.
Freshwater
crab diversity in southwestern Cameroon
The
rainforests of southwestern Cameroon are emerging as a leading biodiversity
hotspot in Sub-Saharan Africa for freshwater crabs (Cumberlidge
1999; Cumberlidge et al. 2019; Mvogo
Ndongo et al. 2020).
This part of the country currently harbours 22 species of freshwater
crabs in five genera all assigned to Potamonautinae (Buea Cumberlidge, Mvogo Ndongo, Clark &
Daniels, 2019; Louisea Cumberlidge,
1994; Potamonemus Cumberlidge
& Clark, 1992; Potamonautes Macleay, 1838;
and Sudanonautes Bott,
1955 (Cumberlidge 1987, 1989, 1993a–c, 1994a,b,
1995a–d, 1999; Cumberlidge & Clark 1992; Cumberlidge & Boyko 2000; Cumberlidge et al. 2019; Mvogo Ndongo et al. 2017a–c, 2018, 2019, 2020)).
The
semi-terrestrial species of freshwater crabs endemic to the rainforests of
southwestern Cameroon are of great conservation importance and are also the
most threatened by anthropogenic activities in these forests (see Table 1). These species are: Buea
asylos (Cumberlidge,
1993), B. bangem Mvogo
Ndongo, von Rintelen, Tomedi-Tabi & Cumberlidge, 2020, B. mundemba
Mvogo Ndongo, von Rintelen & Cumberlidge, 2020,
B. nlonako Mvogo
Ndongo, von Rintelen & Cumberlidge, 2020, Louisea
balssi (Bott, 1969), L.
edeaensis (Bott,
1969), L. nkongsamba Mvogo Ndongo, von Rintelen & Cumberlidge, 2019,
L. yabassi Mvogo
Ndongo, von Rintelen & Cumberlidge, 2019, and Sudanonautes
tiko Mvogo Ndongo, Schubart & Cumberlidge, 2017.
Two of these species, L. balssi
and L. edeaensis, are already
assessed as EN by the IUCN Red List, and were previously thought to be extinct
until their rediscovery in 2017 and 2018 (IUCN 2003; Cumberlidge
2008a,b; Cumberlidge et al. 2009; Mvogo
Ndongo et al. 2017a; 2018). These threatened species of freshwater crabs
are found in an area of great conservation interest, because their aquatic
habitats also serve as key spawning grounds for fish and invertebrates, as well
as refugia for other forest wildlife, e.g., monkeys, drills, chimpanzees, and
gorillas as well as manatees, elephants, birds, turtles, snakes and amphibians
(Cumberlidge et al. 2019; Mvogo
Ndongo et al. 2017a–c, 2018, 2019, 2020). Consequently, these areas increasingly
attract scientists and tourists.
The high
rate of endemism of freshwater crabs in southwestern Cameroon reflects their
low dispersal abilities arising from a lifecycle that includes direct
development of eggs into young crabs, without the highly dispersive planktonic
larval stages seen in marine crabs (Cumberlidge &
Daniels 2007). Most of these endemic
species of freshwater crabs (B. bangem,
B. mundemba, L. balssi,
and L. edeaensis) are still only known
from a single population. Other species
are better known and are represented by at least two populations, most likely revealing
strong phylogeographical structuring.
Despite advances in our knowledge of the taxonomy, habitat, and
distributional range of each of these species, information on their
reproductive biology, ecology, phylogeography, and
evolutionary relationships is still extremely limited. This is a problem because of the urgent need
to provide vital biological data that are necessary for the management of the
freshwater crabs of southwestern Cameroon and to monitor changes in their
populations and habitat as a result of conservation interventions. The present study aims to formulate
guidelines towards a more sustainable use of forest and aquatic resources from
southwestern Cameroon, and lay the groundwork for a conservation assessment of
those species of endemic freshwater crabs most vulnerable to anthropogenic
threats.
MATERIAL AND METHODS
The data
presented here for L. yabassi were
compiled during field surveys of the rivers, streams, wetlands, and nearby land
in the Ebo Forest near Yabassi
in December 2019 and March 2020. The
number of plants destroyed by natural and human activities was assessed at the
locality and around the sampling sites.
The pH and temperature of water samples where crabs occurred were
measured (Table 2), and specimens were identified using the keys provided by Cumberlidge et al. (2019) and Mvogo
Ndongo et al. (2019; 2020). Carapace measurements of each specimen were
taken using digital callipers, and sex and age were recorded. Photographs of freshly caught specimens and
the habitat from where they were collected (Image 1) are also provided. Most specimens were returned to their place
of origin, except for one adult male and female, which were preserved in
ethanol for subsequent detailed morphological and molecular analyses.
RESULTS
The updated
distributional range of L. yabassi is
presented in Figure 1A. The two
populations recently discovered in the Ebo Forest were
collected from two small streams (‘stream-1’ and ‘stream-2’) that flow
independently into the Dibamba River at the locality N’dogbanguengue (Figure 1B). The first population (15 males and five
females) was found ca. 10m from the middle of stream-1 in December 2019 (Figure
1B, Image 2A). At that time of the year,
the water levels of the streams and rivers are at their peak and are difficult
to sample, so all of our specimens of L. yabassi
were collected from semi-aquatic habitats on land, adjacent to the streams in
damp conditions in puddles, under fallen leaves, and in burrows. The second population of L. yabassi (nine males and six females) was found ca.
8m from the middle of stream-2 in March 2020 (Figure 1B, Image 2B). At this time of the year, the water levels of
the streams and rivers are much lower, so that sampling in the large streams
was now possible under the rocks and boulders that sheltered crabs (Image
2). Most of the natural vegetation at
these localities had been destroyed as a result of human activities (by
foresters, farmers, and others). The
trees had been logged to build huts, camps, and toilets. The remaining vegetation in these locations
had been removed for intensive agricultural practices and for firewood. In addition, the farmers encroaching on these
habitats use agro-chemicals and pesticides on their
crops, and these pollutants eventually drain into the aquatic systems and can
poison the freshwater communities.
DISCUSSION
Current
threats to Louisea yabassi
Deforestation,
together with intensive and encroaching agricultural practices, are serious
issues. These activities present
imminent threats to southwestern Cameroon’s rich aquatic biodiversity, which is
of concern, because this area includes a number of rare endemic species. Large scale habitat disturbance also has a
negative impact on the culture of the indigenous people of this region, who
depend on the intact forest for their livelihoods. For example, the Pygmy forest people of this
part of Cameroon express their problems as follows. “[…] We are in the midst of
huge desolation, we no longer recognize the forest, we no longer understand
what is happening. Our forests change
from one day to the next. What future
awaits our children? The settlements destroy the forest, and the felling of
trees prevents us from gathering honey to feed our children. The noise of their huge machines is causing
the animals to flee far away. The trees
falling into the rivers and small streams alter the water flow, and the muddy
stream beds harm the animals and plants.
Some fruits are becoming scarce and we have to walk for a long time to
find them. And the mushrooms we used to
gather everywhere are gone. [...] Our children have no future. Where will they
find animals to hunt? The bark, the leaves and the fruits for curing and
eating? [...]” (See World Rainforest Movement Report, November, 2002, Page 36).
Deforestation
has direct effects on the aquatic environment and indirect impacts from changes
within the drainage basin, both of which will affect rare endemic forest
species, such as L. yabassi, that
depend on the forest canopy remaining closed and intact (Cumberlidge
& Sachs 1991; Dudgeon et al. 2005; Mvogo Ndongo et al. 2018).
Not only does deforestation expose aquatic systems and their inhabitants
to the heating and drying effects of direct sunlight, but local farming
practices also release pollutants such as agro-chemicals
potentially affecting the eggs, hatchling-carrying females, and adults of L.
yabassi.
In addition, clearing the tropical rainforest leads to increased
agricultural encroachment and firewood collection, which further impacts the
habitat of L. yabassi.
Conservation
recommendations
The
extinction risk status of L. yabassi
has not yet been assessed, but the data now available allow us to present a
preliminary pre-assessment.
Unfortunately, the two additional localities for this species are so
close together that IUCN Red List protocols treat them as a single
location. This is because the
calculation of the extent of occurrence (EOO, the area contained within the
minimum convex polygon around all sites of present occurrence) and the area of
occupancy (AOO, the area within the EOO that is actually occupied by the taxon)
requires at least three locations. Despite this, if an IUCN Red List extinction
risk assessment were to be made, then we anticipate that L. yabassi would be assessed as Critically Endangered
(CR) under criterion B alone using the small number of locations, the low
population levels, the disruption of the habitat, and the severity of the
immediate known threats.
The obvious
nature and the large scale of the threats to the habitat of L. yabassi in the Ebo
Forest mean that a conservation action plan needs to be formulated if this
threatened species is to be protected from the anthropogenic threats it is
facing. Conservation actions include the
monitoring of populations, studies of population genetics, and protection
against threats. These actions would
also include a strategy for communication and education of the stakeholders in
the local community about the consequences of engaging in forest destruction,
firewood collection, and agricultural encroachment. Local knowledge from indigenous people should
also form part of the conservation messaging.
Conservation action on a local scale is feasible because of its
‘low-tech’ approach that is necessary (and successful) in the context of rural
Africa. The content of the educational
messaging needs to be structured to highlight the need for protection and to
emphasise the potential advantages brought to the area by increased numbers of
visitors (eco-tourists and scientists).
The targeted stakeholders in the local communities should be brought to
understand that L. yabassi is found
only in the remaining rainforest tracts around Yabassi,
and that this habitat is globally unique.
The semi-terrestrial lifestyle of L. yabassi
means that its habitat ranges from permanent streams to seasonal shallow waters
and wetlands, all of which are impacted by intensive destructive agricultural
practices that degrade and pollute the natural vegetation. The release of pesticides into the
environment containing substances that either harm or kill most species of
invertebrates and vertebrates (most certainly including L. yabassi) needs to be mitigated. In addition, these pesticides have been
linked to a wide range of human health hazards ranging from headaches and
nausea to cancer, reproductive harm, and endocrine disruption. Pesticides have also been linked to nerve,
skin, and eye irritation, dizziness, fatigue, and even sometimes fatal systemic
poisoning (Roberts & Reigart 2013).
In addition
to highlighting the problems facing the rainforest around Yabassi
and the Ebo Forest, the education of the local people
and the Government includes the need for awareness building about the broader
lasting benefits of conservation action.
These include hosting and guiding tourists and scientists from Cameroon
and all around the world attracted by Africa’s intact tropical rainforest
ecosystems and associated unique wildlife.
Further, the local markets and hospitality industry in the area will
benefit from the increased flow of visitors, and this will contribute to the
development of the local community. The
problem of firewood collection requires the promotion of the legal harvesting
of forest resources found in the forested habitat of L. yabassi. This
distinction is important because there are no alternative sources of
firewood other than the natural rainforest itself. Legal exploitation of forest resources
involves avoiding cutting young trees and bushes, and only cutting off dead
branches or using parts of the trees that fall naturally. It also means that the vegetation that falls
around streams should be left untouched, because this constitutes good habitat
for aquatic invertebrates, including L. yabassi. As for agricultural encroachment, it is
necessary to recommend to farmers to focus their attention on land that has
already been used for cultivation and direct them away from the natural
vegetation around the streams that form the habitat of L. yabassi. What
this study suggests is that farmers should curtail their activities, avoid
disturbing the natural vegetation near aquatic habitats and keep these
watersheds free from pesticides.
The success
of this conservation action also requires public training/education sessions
(workshops) aimed at involving a wider section of the local community beyond
those individuals encountered during field work. Monitoring strategies for L.
yabassi mean that local young people,
students, and engineers need to be trained in how to communicate the above
educational messages, and how to undertake routine monitoring to collect data
on the organisms present in a habitat and general ecosystem health. The local authorities (e.g., the chiefs of
the villages, sub-prefets, and prefets)
need to be directly involved, because educational messaging in the community is
an ongoing process, and the involvement of community leaders is key to engaging
the wider community in these conservation efforts. The targets of the educational messages
(local people, fishermen, farmers, foresters, hunters, and other scientists)
should also be made aware of the need to constantly monitor the health of the
habitat, such as monitoring changes in forest cover, agricultural practices,
and the expansion of farms. As
conservationists it is of great importance to inform people on the broader role
of biodiversity (vertebrates and invertebrates) in the rainforest ecosystem and
why illegal poaching of wildlife (e.g., gorillas, chimpanzees, and numerous
bird species) and unsustainable fishing practices (such as small mesh size of
nets, unenforced fishing seasons, and fishing with poison) requires
controlling.
Table 1. Semi-terrestrial species of
primary freshwater crabs endemic to southwestern Cameroon that have been
described or redescribed in the last five years,
along with the number of populations, locality, habitats, main threats, and
IUCN Red List status.
Genus |
Species |
Number of
known populations |
Locality |
Habitat |
Main threats |
IUCN Red List status |
Buea |
B. asylos |
2 |
Kumba (Southwestern region) |
Streams |
Forest destruction, firewood
collection, agricultural encroachment, habitat fragmentation (Mvogo Mvogo Ndongo
et al. 2020) |
VU (Cumberlidge
2008a,b) |
B. bangem |
1 |
Bangem (Southwestern region) |
Streams, puddles, and in the damp conditions under stones,
and in burrows |
Forest destruction, firewood
collection, agricultural encroachment, habitat fragmentation (Mvogo Ndongo et al. 2020) |
NA |
|
B. mundemba |
1 |
Mundemba (Southwestern region) |
Streams, puddles, and in the damp conditions under stones,
and in burrows |
Forest destruction, firewood
collection, agricultural encroachment, habitat fragmentation (Mvogo Ndongo et al. 2020) |
NA |
|
B. nlonako |
2 |
Nlonako (Eastern and
northern slopes) (Littoral region) |
Streams, puddles, and in the damp conditions under fallen
leaves, and in burrows |
Forest destruction, firewood
collection, agricultural encroachment, habitat fragmentation, agro-chemical release (Mvogo Ndongo et al. 2020) |
NA |
|
Louisea |
L. balssi |
1 |
Manengouba (Southwestern region) |
Streams, puddles, and in the damp conditions under fallen
leaves, and in burrows |
Forest destruction, firewood
collection, agricultural encroachment habitat fragmentation (Mvogo Ndongo et al. 2018, 2019) |
EN (Cumberlidge
2008a,b) |
L. edeaensis |
1 |
Bedimet Island of Lake
Ossa (Littoral region) |
Streams, puddles, and in the damp conditions under fallen
leaves, and in burrows |
Forest destruction, firewood
collection, agricultural encroachment, agro-chemical
release invasive plants, (Mvogo Ndongo
et al. 2017a, 2019) |
EN (Cumberlidge
2008a,b) |
|
L. nkongsamba |
3 |
Nlonako (Eastern,
southern, northern slopes) (Littoral region) |
Streams, puddles, and in the damp conditions under fallen
leaves, and in burrows |
Forest destruction, firewood
collection, agricultural encroachment, habitat fragmentation, agro-chemical release. (Mvogo Ndongo et al. 2019) |
NA |
|
L. yabassi |
2 |
Ndogbanguegue, Yabassi (Littoral region) |
Streams, puddles, and in the damp conditions under fallen
leaves, stones, and in burrows |
Forest destruction, firewood
collection, agricultural encroachment, habitat fragmentation |
NA |
|
Sudanonautes |
S. tiko |
2 |
Tiko, Edea (Littoral and southwestern
regions) |
Wetlands, in puddles, and in
the damp conditions under small stones |
Forest destruction, firewood
collection, agricultural encroachment, agro-chemical
release. (Mvogo Ndongo et
al. 2017b) |
NA |
NA—not
assessed | EN—endangered | VU - Vulnarable.
Table 2. Field information of two
distinct populations of Louisea yabassi from the Ebo Forest
in southwestern Cameroon, central Africa, showing the geographical coordinates,
water pH, water temperature, and the number of specimens at each locality (all
collected by P.A. Mvogo Ndongo).
Louisea yabassi |
Geographical
coordinates |
pH |
Water
temperature |
Number of
specimens |
Date
rediscovered |
Plant covering around the
locality |
Population N°1 in Stream-1 |
N04.41715°,
E010.20021° |
6.26 |
26.9° C |
20 |
10/12/2019 |
Heavily disturbed |
Population N°2 in Stream-2 |
N04.41646°, E010.
20213° |
6.70 |
26.5° C |
15 |
13/12/2019 |
Heavily disturbed |
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