Population Dynamics and Genetics of Gerbillus nigeriae in Central Sahel: Implications for Rodent Pest Control
Hima Karmadine,
Granjon Laurent,
Gauthier Philippe,
Ndiaye Arame,
Brouat Carine,
Dobigny Gauthier
Issue:
Volume 4, Issue 4, December 2019
Pages:
45-54
Received:
17 September 2019
Accepted:
21 October 2019
Published:
31 October 2019
Abstract: Gerbillus nigeriae is a sand-dwelling and semi-arid adapted rodent species restricted to the West African Sahel where it causes extensive damages to cereal crops such as millet and sorghum. It also displays one of the most extensive floating chromosomal polymorphisms currently known in mammals, showing a non-random spatial distribution of diploid numbers (2N). We combined population dynamics and genetics to determine dispersal and mobility parameters of G. nigeriae in the species distribution range characterized by low 2N. To do so, we performed a three-year long population survey at Gangara, in the central east Niger. We used both time-dependent monitoring trough capture-mark-recapture (CMR) methods and genetic analyses performed on the 134 monitored individuals. CMR results showed low to very low population densities (maximum 27.5 individuals/ha) throughout the study. Abundance cycle was single-phased and strongly dependent on rainfall patterns. Mobility parameters showed very low individual mobility, with means of distance between successive (re) captures (DRS) and maximal distance between (re) captures (DMR) of 7.8 and 14.4 meters, respectively. Genetic analyses revealed significant isolation by distance as well as spatial structuration, thus confirming poor dispersal capacity. Our results are discussed in terms of rodent pest control in arid areas of Niger where cereal crops production is crucial for human food security.
Abstract: Gerbillus nigeriae is a sand-dwelling and semi-arid adapted rodent species restricted to the West African Sahel where it causes extensive damages to cereal crops such as millet and sorghum. It also displays one of the most extensive floating chromosomal polymorphisms currently known in mammals, showing a non-random spatial distribution of diploid n...
Show More
Cross-species Amplification of Scallop Microsatellites in the Family Pectinidae
Issue:
Volume 4, Issue 4, December 2019
Pages:
55-59
Received:
3 September 2019
Accepted:
24 September 2019
Published:
7 November 2019
Abstract: In the present study, 103 microsatellite markers were selected for cross-species amplification in four marine economic scallop species (Argopecten irradians, Chlamys farreri, Chlamys nobilis, and Mizuhopecten yessoensis) belonging to the family Pectinidae. As a result, in the 72 markers originated from C. farreri, 12 showed amplification products in C. nobilis, 12 in A. irradians and 11 in M. yessoensis. In the 12 markers developed from M. yessoensis, four markers could be amplified successfully in A. irradians, three in C. farreri, and one in C. nobilis. In the nine markers isolated from C. nobilis, two markers could be cross-amplified in A. irradians and one in M. yessoensis, but no marker was likely to be useful in C. farreri. In the nine markers of A. irradians, one marker was potentially workable for C. farreri, one in M. yessoensis, but none in C. nobilis. When the microsatellites were cross-species amplified, most of the PCR products showed low yield and ambiguous bands, while the numbers of alleles also decreased. Finally, three markers (CFMS016, CFCD131 and CFE04) were revealed to be successfully transferred among the four species providing candidate markers for ecological study of scallops, while most of the other markers were unique for one species with poor cross-species amplification, which might be useful for species identification.
Abstract: In the present study, 103 microsatellite markers were selected for cross-species amplification in four marine economic scallop species (Argopecten irradians, Chlamys farreri, Chlamys nobilis, and Mizuhopecten yessoensis) belonging to the family Pectinidae. As a result, in the 72 markers originated from C. farreri, 12 showed amplification products i...
Show More
Woody Plant Species Diversity of Gechi In-situ Forest Conservation Site, Sekela District, North Western Ethiopia
Tensay Ayalew,
Sisay Alemu,
Edeget Merawi
Issue:
Volume 4, Issue 4, December 2019
Pages:
60-71
Received:
29 May 2019
Accepted:
30 October 2019
Published:
11 November 2019
Abstract: The study was conducted at Gechi in-situ forest conservation site to investigate woody plant species diversity. To collect the inventory data, a systematic and predetermined sampling system was followed. The main objectives of the study was to undergo inventory of the indigenous woody species, assessing the regeneration status, to determine the floristic composition and set the priority list of woody plant species for the vegetation of the area. Study was conducted during in January 2019. Gechi in-situ conservation site land feature was valley the transect line was laid along the valley ridge. All ten transects ware laid from west to east direction with forward bearing of 32°, between transects 150mt distance and also the quadrates were established with regular interval of 200 m from each other. In general, a total of three transects, 31 quadrates and 62 sub-quadrates were used to collect the inventory data from the Gechi in-situ site vegetation. From the inventoried a total of 47 woody plant specimens were collected; out of which 46 specimens were identified to the species level. Major threat of the Gechi forest recording during the study were 1.1% clearing for agriculture, 31.1% and 34.4% of the negative impacts were attributed by browsing and grazing respectively with moderate and intensive (heavy) levels and also 33.3% of forest was cutting of Bamboo for fence construction with the intensity of moderate to intensive disturbance level. To overcome forest disturbance proper conservation has to be taken to solve the problems and prevent the forest from forest disturbance factors.
Abstract: The study was conducted at Gechi in-situ forest conservation site to investigate woody plant species diversity. To collect the inventory data, a systematic and predetermined sampling system was followed. The main objectives of the study was to undergo inventory of the indigenous woody species, assessing the regeneration status, to determine the flo...
Show More
