Potamonautes gorongosa, a new species of potamonautid freshwater crab (Decapoda, Brachyura) from Mozambique, southeastern Africa

James

Gouws

2020

Aquatic Conservation

1. In the present study, the phylogeography of the only southern African freshwater crab listed as Vulnerable (VU) on the International Union for Conservation of Nature (IUCN) Red List, Potamonautes lividus, was investigated by surveying several localities in the Eastern Cape and KwaZulu-Natal provinces in South Africa. Both nuclear and mitochondrial DNA (nDNA and mtDNA) markers were used and, as it was hypothesized that marked genetic differentiation should be present, niche modelling was undertaken to explore the distribution of the species along the east coast of South Africa. In addition, shortfalls in the present approach to IUCN Red Listing, as illustrated by this Vulnerable species of crab, are discussed. 2. Results from the mtDNA revealed the presence of two haploclades, confined to specimens from the two provinces, respectively, and the general absence of maternal dispersal, a fact that was further validated by the fixation index (F ST) data and high Φ ST values. Within the Eastern Cape haploclade, low-frequency maternal dispersal occurred, corroborated by the low value of F ST. In contrast, no haplotypes were shared in the KwaZulu-Natal haploclade, as corroborated by the marked differences in F ST. 3. The microsatellite data demonstrated the presence of higher frequency, possibly paternally biased, dispersal of specimens between the Eastern Cape and KwaZulu-Natal provinces. The results suggest the presence of two distinct management units within P. lividus. An estimate of divergence time suggests a late Pleistocene cladogenesis between the Eastern Cape and KwaZulu-Natal haploclades. 4. Considering the presence of P. lividus in several newly formed nature conservation areas in both provinces, and its potential presence in the intermediary area, based on maximum entropy (Maxent) niche modelling, our data suggest that the species status in the IUCN Red List should be downgraded to Least Concern. 5. A comparison of all the Endangered, Vulnerable, and Critically Endangered IUCN Red Listed freshwater crabs for the entire Afrotropical region reveals the lack of recent sampling in the three biodiversity hot spots in West, Central, and East

Section: Introductionmentioning

confidence: 99%

Phylogeographic structure and continued surveys of a Vulnerable South African freshwater crab (Potamonautidae, Potamonautes lividus): Implications for the IUCN Red Listing of the Afrotropical fauna

James

Gouws

2020

Aquatic Conservation

“…In the countries neighbouring South Africa, such as Eswatini, Mozambique and Zimbabwe, limited sampling of freshwater habitats has occurred, suggesting that in these countries the diversity of freshwater crabs and other crustaceans is likely underestimated. For example, research in Mozambique has resulted in the description of four new freshwater crab species (P. bellarussus, P. gorongosa, P. namuliensis and P. licoensis) (Daniels & Bayliss 2012;Daniels et al 2014Daniels et al , 2020bCumberlidge et al 2017) while two additional species from high altitude mountain streams still await formal description. All four of the aforementioned species were collected from inaccessible mountain areas that have not been sampled in decades.…”

Section: Discussionmentioning

confidence: 99%

Surveys of Afrotemperate forests yields two new freshwater crabs (Decapoda: Potamonautidae: Potamonautes MacLeay, 1838) from South Africa

Barnes²,

Marais³

et al. 2021

EJT

663

Sampling of remote inland aquatic habitats in South Africa has constantly been yielding novel endemic freshwater crab species (Potamonautes MacLeay,1838). During the present study, we report on the discovery and description of two new freshwater crab species (Potamonautes baziya sp. nov., and P. mariepskoppie sp. nov.) from Afrotemperate forested mountain regions in the Eastern Cape and Mpumalanga provinces of South Africa, respectively. Phylogenetic evidence derived from DNA sequence data of three partial mitochondrial loci (12S rRNA, 16S rRNA and cytochrome oxidase subunit one, COI) corroborates the evolutionary distinction of the two novel species. In addition, morphological and ecological data for the two new species further delineate their evolutionary distinction from congeneric sister species. A comparison of the taxonomically important gonopods 1 and 2 and carapace features among the sister species and other known freshwater crabs of South Africa was further used to provide evidence for the distinction of the two novel species. The discovery of two new species suggest that remote mountainous areas or unsampled regions in South Africa likely harbor several novel species, reiterating a call to document aquatic inland biodiversity in forested and mountainous regions of the country.

“…Similarly, recent biotic surveys of the 'sky islands' in Mozambique led to the discovery of three endemic freshwater crab species: P. bellarussus Daniels, Phiri & Bayliss, 2014 from Yao Mountains, P. namuliensis Daniels & Bayliss, 2012 from Mount Namuli and P. gorongosa Cumberlidge, Naskreski & Daniels, 2016 from Mount Gorongosa. Currently, ten freshwater crab species are known from Mozambique (Cumberlidge et al 2016). Extrapolating the results for the freshwater crabs to other understudied groups, it would be reasonable to assume that the hitherto described level of biodiversity has been underestimated.…”

Section: Introductionmentioning

confidence: 99%

Phylogenetics of the freshwater crab (Potamonautes MacLeay, 1838) fauna from ‘sky islands’ in Mozambique with the description of a new species (Brachyura: Potamoidea: Potamonautidae)

Bittencourt-Silva

Muianga³

et al. 2020

EJT

Self Cite

785

Patterns and processes of cladogenesis among taxa living on the Mozambique ‘sky islands’ remain poorly studied. During the present study, we report on a new freshwater crab species from Mount Lico, an inselberg and ‘sky island’ in the Zambezia Province of Mozambique. Phylogenetic analyses using three mitochondrial DNA sequence loci (12S rRNA, 16S rRNA and COI) were used to determine the evolutionary placement of the freshwater crab specimens from Mount Lico. The freshwater crab specimens from Mount Lico were retrieved sister to Potamonautes choloensis. The new species, Potamonautes licoensis sp. nov., is described and compared with other southern African freshwater crab species. Divergence time estimations for the Mozambican freshwater crab species suggest a Miocene / Plio–Pleistocene diversification. Some endemic ‘sky island’ species form an early branching and are sister to other predominantly East African species, while other ‘sky island’ species are more recently derived and nested within a predominantly southern African clade. The present study presents the description of the fourth endemic freshwater crab species from Mozambique and suggests that the species diversity in the country is likely highly underrepresented, reiterating the call for renewed systematic surveys. An argument for the conservation of these mountainous ‘sky islands’ is presented.