Suncus etruscus (Soricomorpha, Soricidae): A new species for Elba Island (Tuscan Archipelago, Italy)

The following study contains a report regarding the first record of presence of Suncus etruscus on the island of Elba. We considered original and literature data obtained from the analysis of Barn owl (Tyto alba) pellets. Three roosts located in different areas of Elba (Marciana: Colle d'Orano-Patresi; Campo nell'Elba: La Grotta; Portoferraio: Casa Rossa) have been monitored since 1968. The presence of the Pygmy white-toothed shrew has only been observed at one roost (Casa Rossa) since 2004. We performed a biometrical analysis of 15 skull characters on 67 specimens of 'S. etruscus. From the results, we conclude that a colonization of the island by S. etruscus is in progress, but long-term monitoring is needed in order to control the status of the population

Allozyme variation and divergence in the phyllotine rodent Calomys hummelincki (Husson, 1960)

The aim of the present study was to assess the degree of genetic variation and divergence among six populations of Calomys hummelincki, a phyllotine rodent distributed in northern South America. With this information we will try to evaluate the two hypotheses of possible colonization and differentiation of this group of rodents postulated by Baskin and Reig. We studied 34 loci by electrophoretic analysis: 21 were monomorphic for all populations and 13 were polymorphic in at least one population, being P1%=21.6% the mean value for all populations. The mean value of heterozygosity per locus was H=0.075. Low values of genetic distance were observed among populations of the Llanos region (0.001<D<0.006). There was a larger genetic distance (D=0.024) between the population from Isiro, in the northwestern semiarid region, and those from the Llanos region. The insular population of Aruba displayed the lowest value of genetic distance with the population from Isiro (D=0.014). The specimens from Sipao, on the right side of the Orinoco river, displayed the highest values of genetic distances in comparison with other populations of C. hummelincki (0.070<D<0.095). The relatively high differentiation was due to the fixation of new alleles, not found in other populations of C. hummelincki, at loci Idh-1 and Est-2. F-statistics and Nm values indicated reduced gene flow among the populations sampled. Despite the limited data, the results seem to support Reig's hypothesis about south to north colonization of genus Calomys in South America

Evolutive pattern of Calomys hummelincki (Husson, 1960; Rodentia, Sigmodontinae) inferred from cytogenetic and allozymic data.

The main purpose of this research was to understand the evolutive history of the sigmodontine rodent Calomys hummelincki (Husson 1960), tribe Phyllotini from chromosomal and allozymic data, and evaluate the hypotheses that explains the colonization and evolution of sigmodontine rodents in South America. C. hummelincki is restricted to the Northern South American region, which comprises Venezuela, Aruba and Curaçao islands where specimen sampling was done. The cytogenetic analysis showed that all populations studied have the same diploid number (2n=60) and fundamental number (FN=64). Constitutive heterochromatin was observed on pericentromeric positions in almost all chromosomes. NOR regions were observed on four pairs of acrocentric chromosomes. G-banding allowed us to identify almost all pair positions in the C. hummelincki chromosome complement. The G-banding also permitted a comparison of the C. hummelincki pattern with those published for C. callidus, C. venustus and C. laucha species. G-banded information indicates that hummelincki is not directly derived from laucha. The results are constrained with published allozymic and molecular data obtained in previous studies. The overall analysis seems to support Reig´s hypothesis of a south to north colonization of genus Calomys in South America