Here, we present the ITS ribosomal DNA (rDNA) sequence data on 330 larvae of nematodes of the genus Anisakis Dujardin, 1845 collected from 26 different bony fish species from 21 sampling locations and different climatic zones. New host records are provided for Anisakis simplex (Rudolphi, 1809) sensu stricto (s.s.) and A. pegreffii Campana-Rouget et Biocca, 1955 from Anoplopoma fimbria (Pallas) (Santa Barbara, East Pacific), A. typica (Diesing, 1860) from Caesio cuning (Bloch), Lepturacanthus savala (Cuvier) and Katsuwonus pelamis (Linnaeus) (Indonesia, West Pacific), A. simplex s.s. from Cololabis saira (Brevoort) (Hawaii, Central Pacific), A. simplex C of Nascetti et al. (1986) from Sebastolobus alascanus Bean (Santa Barbara, East Pacific) and A. physeteris Baylis, 1923 from Synaphobranchus kaupii Johnson (Namibia, East Atlantic). Comparison with host records from 60 previous molecular studies of Anisakis species reveals the teleost host range so far recorded for the genus. Perciform (57 species) and gadiform (21) fishes were the most frequently infected orders, followed by pleuronectiforms (15) and scorpaeniforms (15). Most commonly infected fish families were Scombridae (12), Gadidae (10), Carangidae (8) and Clupeidae (7), with Merluccius merluccius (Linnaeus) alone harbouring eight Anisakis species. Different intermediate host compositions implicate differing life cycles for the so far molecularly identified Anisakis sibling species.
Multimammate mice of the genus Mastomys are widespread in sub-Saharan Africa and occur in a wide range of open habitats. Representatives of this genus are the most common African rodents, the main vertebrate agricultural pests and vectors of human pathogens. In Ethiopia, the biogeographically most complex eastern African country, several species have been reported, but their distribution has never been described because of their cryptic morphology. Here we present genetically identified species from 377 Ethiopian Mastomys specimens and analyse their distributional patterns. The genus, represented by four species, inhabits most of the country, with the exception of the highest mountains and dry areas, such as the Afar triangle and the Somali region. For the first time we document M. kollmannspergeri from a single locality in the northernmost part of Ethiopia. Three previously recorded species are more widespread – M. erythroleucus was found at 32 localities, M. natalensis at 13 localities and the Ethiopian endemic species M. awashensis at 18 localities. and Phylogenetic analysis of mitochondrial cytochrome b gene sequences indicates that only one of the six phylogroups of M. natalensis and one of the four phylogroups of M. erythroleucus are represented in Ethiopia. Haplotype network analysis indicates two subclades of Ethiopian M. erythroleucus separated by the Ethiopian Rift Valley. Using presence records, we constructed distribution models for the species and analysed the level of overlap. The predicted distribution shows most overlap between M. awashensis and M. natalensis, which is in agreement with empirical data as both species were found in sympatry at four localities. A medium level of overlap was predicted between M. natalensis and M. erythroleucus and both species were found co-existing at two localities. This study not only presents the first detailed distribution of cryptic Mastomys species, but also clearly identifies multimammate mice as model taxa for future evolutionary studies (e.g. the evolution of coexistence or host-parasite interactions) and indicates the regions suitable for such studies.
The phylogenetic relationships of the three major species groups of Tribolium (Coleoptera: Tenebrionidae) were inferred using the simultaneous analysis of 642 bp of the most conserved part of mitochondrial DNA (mt DNA) cytochrome oxidase I (COI) and 448-452 bp of mt 16S rDNA. High sequence divergence was observed for both genes even among sibling species. The analysis of the combined segments of COI and 16S rDNA sequences produced a phylogenetic tree with moderate level of confidence. The tree topology showed monophyly of the genus Tribolium whose species were separated into three groups: "brevicornis" group (with T. brevicornis as the only representative), "castaneum" group (with T. castaneum, T. freemani, T. madens and T. audax) and "confusum" group (with T. confusum, T. anaphe and T. destructor). Sibling species pairs T. castaneum - T. freemani and T. madens - T. audax are clearly resolved. The preliminary results presented here give moderate support to the previously proposed phylogeny based on morphological data.
The sibling species H. yedoensis Takizawa coexists sympatrically and simultaneously with H. axyridis only on pine trees in Japan. To elucidate the mechanisms enabling coexistence of these two sympatric sibling species, a laboratory experiment was performed that focused on differences in their maternal investment through eggs and the role of sibling cannibalism. The egg size (volume) of H. yedoensis was 24.91% larger than that of H. axyridis. Cluster size in H. axyridis was significantly larger than that in H. yedoensis; however, the total number of eggs and oviposition cost (by volume) per female in H. yedoensis were not significantly different from those in H. axyridis, although total number of clusters tended to be slightly higher in H. yedoensis than in H. axyridis. The percentage of undeveloped eggs per cluster in H. yedoensis was not significantly different from that in H. axyridis, whereas the percentage of developed eggs with delayed hatching per cluster was significantly larger in H. yedoensis than in H. axyridis. Moreover, the cost of sibling cannibalism per hatched larval cluster in H. yedoensis (worth 4.43 sibling eggs) was 3.36 times larger than that in H. axyridis.Therefore, maternal investment through egg and sibling cannibalism in developed eggs with delayed hatching are more intense in H. yedoensis than in H. axyridis, implying a higher larval survival rate through higher ability of prey capturing at the first instar. The results in this study suggest that the higher survival rate and accelerated development in H. yedoensis by the two maternal investments, i.e., a large egg and intense sibling cannibalism of developed eggs with delayed hatching, may play an important role in sympatric coexistence with the aggressive aphidophagous ladybird beetle H. axyridis.