Discovery of a novel symbiotic lineage associated with a hematophagous leech from the genus .

Unlabelled: Similarly to other strict blood feeders, leeches from the genus (Hirudinida: Glossiphoniidae) have established a symbiotic association with bacteria harbored intracellularly in esophageal bacteriomes. Previous genome sequence analyses of these endosymbionts revealed co-divergence with their hosts, a strong genome reduction, and a simplified metabolism largely dedicated to the production of B vitamins, which are nutrients lacking from a blood diet. ' Providencia siddallii' has been identified as the obligate nutritional endosymbiont of a monophyletic clade of Mexican and South American spp.

Serpentirhabdias mexicanus n. sp. (Nematoda: Rhabdiasidae), a parasitic lungworm of the nauyaca viper Bothrops asper (Serpentes: Viperidae) in the Mexican Neotropics.

Serpentirhabdias mexicanus n. sp. (Nematoda: Rhabdiasidae) is described from the lung of the nauyaca viper Bothrops asper in Puebla State, central Mexico.

Mitogenome of the blood feeding leech (Hirudinida: Glossiphoniidae) from Tabasco, Mexico.

Here, we present the mitogenome of the blood feeding leech (Hirudinida: Glossiphoniidae) based on specimens collected in Tabasco, Mexico. The circular genome is 14,985 bp in length, and consists of 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and an AT-rich control region. Phylogenetic analysis based on the 13 protein-coding genes and two rRNA genes places sister to within the family Glossiphoniidae.

Microbiome differences between river-dwelling and cave-adapted populations of the fish (De Filippi, 1853).

Symbiotic relationships between host and microbiome can play a major role in local adaptation. Previous studies with freshwater organisms have shown that microbiome performs numerous important biochemical functions for the host, playing a key role in metabolism, physiology or health. Experimental studies in fish groups have found an effect of enzymatic activity of gut microbiota on a variety of metabolic processes.