Characterization of three plant or fungal feeding nematodes (Nematoda, Rhabditida, Tylenchomorpha) from coastal dunes in Spain including the SEM study of these species

Abstract

Three known species, Aphelenchus avenae, Ditylenchus myceliophagus and Tylenchorhynchus aduncus (Rhabditida, Tylenchomorpha), are described from sand coastal dunes in Spain associated to the rhizosphere of xerophilic plants. A. avenae is characterized by having stylet with 16–22 µm long, pharyngeal dorsal gland overlapping the intestine, postvulval uterine sac about 2.5 times the body diameter, female tail short conoid with rounded tip bearing the phasmid and male bursa well developed. D. myceliophagus is characterized by having lateral field with four incisures, stylet 7–8 µm long, basal bulb irregularly pyriform, tail of both sexes similar with rounded tip and bursa of the male reaching about three-quarters of tail length. T. aduncus is characterized by its lateral field with six incisures, stylet 15–18 μm long, spicules with bifurcate tip and distal ventral crest, and gubernaculum with hook-like manubrium. New morphological, including SEM study, and morphometrical data are included for the three species. Also, phylogenetic analysis based on 18S and 28S rDNA is included for two of the species studied. Additionally, two species belonging to the superfamily Aphelenchoidea are transferred to other genera: Aphelenchus assamensis to the genus Aphelenchoides and Aphelenchoides dhanachandi to the genus Potensaphelenchus.

Prevalence and Distribution of Nematodes from Coastal Sand Dunes in the Iberian Peninsula

“…At a later date, various researchers evidenced the presence of nematodes associated with these types of ecosystems around the world in America [3], Europe [19][20][21][22][23][24][25], Asia [7], and Africa [26,27]. With respect to the Iberian Peninsula, the most relevant studies of species of nematodes from sand coastal dunes have been carried out by several authors at the southeast of the peninsula [28][29][30][31][32] and other areas [33][34][35][36][37], describing some new species associated to these sand dunes. Their results show that nematodes belonging to the order Rhabditida are the predominant organisms in these ecosystems since they present adaptations to arid and drought conditions that allow them to survive in this type of environment [38].…”