Praomys undetermined
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publication ID |
https://doi.org/ 10.1111/j.1096-3642.2011.00733.x |
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persistent identifier |
https://treatment.plazi.org/id/039F8796-FFF0-7C58-7801-991AFB31310D |
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treatment provided by |
Valdenar |
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scientific name |
Praomys undetermined |
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PRAOMYS SPECIES DIVERSITY, GEOGRAPHICAL DISTRIBUTION, AND ECOLOGY
We present the most comprehensive Praomy s phylogeny to date. Based on morphological characteristics, several species complexes were defined within the genus Praomys ( Van der Straeten & Dudu, 1990; Van der Straeten & Kerbis Peterhans, 1999). Our molecular data confirmed these species complexes ( P. tullbergi , P. jacksoni , and P. lukolelae ). According to our molecular analyses, the genus Praomys appears to be paraphyletic, contrary to the recent finding of Lecompte et al. (2008), and it was also found to be paraphyletic in earlier accounts ( Lecompte et al., 2002a, 2005). However, we will not discuss this further as our results are based on only one mitochondrial gene showing a poor resolution of the basal branches. Moreover cyt b is known to have low power for more distant nodes (e.g. Smith & Patton, 1999). We will now discuss all of the clades that include species from the Kisangani region, beginning with clades where our results corroborate earlier findings, and ending with clades for which there are disagreements.
Praomy s misonnei was described from the locality of Irangi, Kivu Province, East of the DRC ( Van der Straeten & Dieterlen, 1987). The craniometric comparison of our specimens from Kisangani with the type specimen of P. misonnei confirmed its presence in the region, on the right bank of the Congo River only.
Praomy s mutoni has been described from Masako, 15 km to the north of the city of Kisangani, on the right bank of the Congo River ( Van der Straeten & Dudu, 1990). The known distribution range of this species was recently expanded to several localities on the right bank (up to 200 km from Kisangani) and three sites on the left bank of the Congo River ( Nicolas et al., 2005; Katuala et al., 2008). We were unable to detect any genetic and craniometric differentiation between the P. mutoni populations from both sides of the Congo River.
Praomy s lukolelae has been included for the first time in a molecular analysis. Praomy s lukolelae was described briefly by Hatt (1934) from Lukolela (Equator Province, DRC), and it is only known from the type locality and the region of Kisangani ( Musser & Carleton, 2005). Praomy s lukolelae was found to be closely related to P. verschureni in our study. Our results do not allow us to resolve the relationship between both species and the other Praomys species. Based on a combination of mitochondrial and nuclear genes, Lecompte et al. (2005, 2008) group P. verschureni together with all other Praomys species. Praomy s lukolelae could thus be considered as a member of the genus Praomys . Praomy s lukolelae occurs on the left bank of the Congo River only, where it is commonly captured in primary tropical rainforest, and is less common in secondary forests, fallows, and fields.
Praomy s jacksoni s.l. represents a complex of cryptic species, as proposed earlier by Musser & Carleton (2005) and Van der Straeten & Dudu (1990). Within P. jacksoni s.l., we recognize at least four molecular clades (clades I–IV), one more than noted by Nicolas et al. (2005). Our craniometric analyses show the presence of P. minor in the Kisangani region on the left bank of the Congo River only. This represents an extension of its geographical range of about 750 km to the east. The species also forms a distinct genetic clade within P. jacksoni s.l. (clade III in Fig. 2 View Figure 2 ). This is the first well-documented record of P. minor after its original description ( Hatt, 1934), which was based on five specimens that were collected at the type locality. Additional samples on the left bank of the Congo River, upstream as well as downstream of our actual trapping sites, are necessary to further specify the geographical distribution range of this species. Our morphometrical results also confirm that P. minor is the smallest of the species attributed to the P. jacksoni s.l. species complex. However, because of considerable overlap, none of the cranial or external measurements included in our study can be used alone to distinguish P. minor from the other clades. Nevertheless, P. minor can easily be separated by means of multivariate analyses of craniometric measurements and sequencing of the cyt b gene. Praomy s minor was captured in primary and secondary rainforest, as well as in fallow lands, and seemed to be a habitat generalist. A recent study confirms its presence in fields ( Crauwels, 2009).
Praomy s minor is not the only species of the P. jacksoni s.l. complex captured on the left bank of the Congo River. Two specimens (one from Djabir and one from Yoko) are linked with an unidentified species collected in West Africa ( CAR, Gabon, Congo- Brazzaville, Cameroon), based on genetic, and for one specimen also craniometric, criteria. This suggests that an undescribed species of the P. jacksoni s.l. complex (clade IV) could be distributed from West Africa to Kisangani, on the left bank of the Congo River. In West Africa, specimens from this group were only captured in gallery forest along river courses, in secondary forest, and in old fallows, not in young fallow land (V. Nicolas, pers. comm.). Curiously, in Kisangani, the specimens were captured in an old palm plantation (Djabir) and in young fallow land (Yoko). However, as our significant sampling effort yielded only two specimens, the species is either very rare or is very trap shy (which is not the case in Gabon, CAR, and Congo-Brazzaville). It is possible that this species has its greatest distribution range limit in the Kisangani region, and therefore occurs in less suitable habitat because of resource competition number
Total
individuals
93 71 49
per species.
of 278 108 114
Fields 5 – – – – 8 indicated is
Riverside 12 5 13 – – – analyses this
land for fallow rivers included
Old near – –
14 – – –
land individuals
fallow rivers of
Young near – – 52 7 – 6 number total
fallow The
Old
land 9 5 – 12 – –. shown
fallow is
Young land 23 26 3 8 11 8 habitat habitat each in per Secondary forest 34 47 14 12 56 8 caught specimens Primary forest 17 17 4 61 33 70 species captured II VI, I VII per of. Distribution 4 jacksoni . clade cf clade misonnei mutoni clade V clade III minor clade jacksoni . cf only Kisangani region lukolelae clade percentage specimens of Table Praomys Praomys Praomys Praomys Praomys Praomys The with the other Praomys species. Species often have a lower population density at the edges of their distribution range ( Brown, 1984). Additional sampling is necessary to confirm the absence of the species on the right bank: this species may be present but in very low numbers, and thus remains undetected. Nonetheless, there were considerable trapping efforts made on the right bank.
On the right bank of the Congo River, two genetic clades are present (clades I and II): clade I encompasses the right bank of the Aruwimi River, including the specimens from Kenya, Uganda, and Epulu ( DRC). Within this group, two smaller clades seem to exist: Kenya and Uganda / DRC. The second clade (clade II) occupies the left bank of the Aruwimi River, including the city of Kisangani itself. Both clades cannot be separated by our craniometric analysis: all the specimens from the Kisangani area form one group, regardless of which side of the Aruwimi River they were collected. All the Ugandan specimens form another group ( P. jacksoni s.s.), but because the number of specimens studied is low, a larger sample size from more localities on both banks of the Aruwimi River might reveal craniometric differences between these two mitochondrial clades. At the moment, we can not be sure whether the group from the right bank of the Aruwimi River (Bomane 1) represents the westernmost population of the described P. jacksoni s.s. from Entebbe ( Uganda) or not. However, the specimens from the Kisangani area are clearly distinct from the described P. jacksoni s.s. from Uganda, both craniometrically as well as genetically. Praomys jacksoni s.s. was previously considered to be a wide-ranging species occurring across tropical Africa by Lecompte, Denys & Granjon (2001). Praomys cf. jacksoni sp.nov. (clade II) occurs in practically all habitats: primary and secondary forests, fallow lands, and small forest relics ( Dudu, 1991; Katuala et al., 2008). These specimens could represent an undescribed species, and research on this clade continues. The genetic differentiation between clades I and II is similar to the level of sequence divergence between other Praomys species such as P. rostratus and P. tullbergi . Our results confirm that the P. jacksoni s.l. complex needs a thorough taxonomical revision. Moreover, several species and/or subspecies were described from East Africa that could not yet be included in this study.
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