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The freshwater gastropod Latia neritoides is endemic to the streams of New Zealand’s North Island. This species has evolved a unique defence system: it exudes a luminescent mucus thought to deter predators. While the bioluminescence itself has been investigated before, the underlying gland system has remained unstudied and relevant information to understand the defence system has been missing till now. For the release of the glowing mucus of L. neritoides two places of origin were assumed: the lateral foot area or the mantel cavity. In this study the focus was on the first suggestion. To gain insight into the defence system, morphological as well as histochemical analyses were performed involving all secretory gland types in the sub-epithelial foot layer. The results were compared with the foot gland system of Neritina sp., a snail living in a comparable habitat, but using a different survival strategy. The gland types of the two gastropods were compared and their mucus types were investigated. Seven subepithelial gland cell types can be distinguished in the foot region of L. neritoides. Neritina sp., in contrast, has six gland cell types of which three laterally located ones are epithelial. Both species show a pedal gland in the anterior foot region. A striking difference between the species are two prominent subepithelial gland cell types (L1l/L2l) in the lateral foot area of L. neritoides, which are missing in Neritina sp. These gland cells are distributed throughout the entire lateral foot area of L. neritoides and make up about 85% of the mucus gland cells in this area. Defence mucus and trail mucus of L. neritoides show different specificities in lectin staining, but are not equally represented in the gland cell types. Yet, based on the huge size and high density of L1l and L2L, we envision a role for these gland types in the defence system.

BACKGROUND: Spirocerca lupi is a parasitic nematode of canids that can lead to a severe and potentially fatal disease. Recently, a new species, Spirocerca vulpis, was described from red foxes in Europe, suggesting a high genetic diversity of the Spirocerca spp. infecting canids. The genetic variation and phylogenetic relationships of S. lupi collected from naturally-infected domestic dogs from Australia, Hungary, Israel, Italy, India and South Africa, and S. vulpis from red foxes from Bosnia and Herzegovina, Italy and Spain, was studied using mitochondrial and rDNA markers. RESULTS: A high intra-individual variation was found in the first internal transcribed spacer (ITS1) locus in all Spirocerca spp., ranging between 0.37-2.84%, with up to six haplotypes per specimen. In addition, a combination of phylogenetic and haplotype analyses revealed a large variability between S. lupi specimens collected from different geographical locations using the ITS1 (0.37-9.33%) and the cytochrome c oxidase subunit 1 (cox1) gene (1.42-6.74%). This genetic diversity led to the identification of two S. lupi genotypes circulating among dogs (PTP support > 0.829), including genotype 1 found in S. lupi from Australia, India, Israel and South Africa, and genotype 2 represented by specimens from Hungary and Italy. These genotypes presented pairwise nucleotide distances of 0.14%, 8.06% and 6.48 ± 0.28% in the small rDNA subunit (18S), ITS1 and cox1 loci, respectively. Additionally, Nei's genetic distance in the ITS1 showed a further subdivision of genotype 1 worms into 1A (Israel and South Africa) and 1B (Australia and India). A morphological analysis of the anterior and posterior extremities of genotype 1 and genotype 2 worms using scanning electron microscopy did not show any differences between the specimens, contrary to the morphological differences between S. lupi and S. vulpis. CONCLUSIONS: These findings demonstrate the high genetic variability among Spirocerca spp. from different ge

Rickettsia felis, the causative agent of flea-borne spotted fever, occurs on all continents except Antarctica, owing to the cosmopolitan distribution of its cat flea vector. In this study, cat fleas were collected in two countries where the occurrence of R. felis was either unknown (Malta) or where accurate prevalence data were lacking (Israel). Altogether 129 fleas were molecularly analysed for the presence of rickettsial DNA. On the basis of three genetic markers, R. felis was identified in 39.5% (15/38) of the cat fleas from Malta. Sequences showed 100% identity to each other and to relevant sequences in GenBank. Among the 91 cat fleas from Israel, two (2.2%) contained the DNA of Candidatus Rickettsia senegalensis. Phylogenetically, the R. felis and Candidatus R. senegalensis identified here clustered separately (with high support) but within one clade, which was a sister group to that formed by the typhus group and spotted fever group rickettsiae. This is the first record of R. felis in Malta and of Candidatus R. senegalensis outside its formerly reported geographical range including Africa, Asia and North America.