In the Republic of Guinea (West Africa), the diversity and distribution of striped grass mice of the genus Lemniscomys is poorly known. In the course of long-term field surveys from 2003 to 2011, we collected 97 specimens from various regions of Guinea with the aim of characterizing the morphological and genetic diversity of the genus in the country. We performed an integrative study that allowed us to detect the existence of at least two species in the collected specimens. Two molecular clades, corresponding to different karyotypes, were recovered. By comparison with type specimens and using classical morphometric analyses, we are able to confirm the presence of L. linulus and L. striatus in Guinea. We redescribe the skull and dental characters of the poorly known L. linulus and report its standard karyotype formula (2N = 56, NFa = 66). We did not collect any L. zebra in Guinea despite its presence in South Mali. In conclusion, the distributions of L. striatus and L. linulus described for Guinea and, including the previously reported L. bellieri, three species are now known to occur in this country. We recognise these three species as valid pending further revision of the genus at a pan-African scale.
Populations of silver Prussian carp (Carassius gibelio) are known to exhibit different ploidy levels among their individuals. No consistent information is available regarding chromosome number of triploid biotype. Generally diploids have 100 chromosomes while triploids have 150-160 chromosomes. The karyotype of the C. gibelio triploid biotype is characterized by a variable number of small chromosomal elements called supernumerary chromosomes. Here we report the results of a reproduction experiment between a diploid male and triploid female with respect to chromosome numbers of the parents and their offspring. Thirty metaphases of both parents and fifteen individuals of the offspring were investigated. We found variability in chromosome numbers among analysed offspring with a fluctuation from 150 to 159. In comparison, the chromosome numbers of male and female individuals were found to be 100 and 159 respectively. Our results show a high chromosomal plasticity of the Carassius gibelio triploid biotype.