Comparative study of four known species of the genus Acrobeles von Linstow, 1877 (Nematoda, Cephalobidae) with 'single' and 'double' cuticle from coastal dunes in Spain

Characterization of Nothacrobeles lanceolatus Abolafia & Peña-Santiago, 2003 (Rhabditida, Cephalobidae), a typical species of coastal dunes from Spain

The nematode Nothacrobeles lanceolatus was described in arid soils from Cabo de Gata-Níjar Natural Park, province of Almería (Spain). Since then this species has not been found again. In this study, new data on the distribution and morphological, morphometrical and molecular characteristics (based on 18S and 28S ribosomal DNA) of N. lanceolatus is provided. This species is characterized by having a tessellated cuticle, with its inner layer bearing two rows of cuticular punctations per annulus, lips quadrangular with eight pinnae, labial probolae bifurcate with divergent prongs surrounded by pinnae, pharynx with corpus 2.5–4.0 times isthmus length, post-vulval uterine sac 1.4–2.2 times the corresponding body diameter, and female and male tails conical, bearing a conical mucro with acute terminus. The phylogenetic position of this and related species of the genus Nothacrobeles is discussed. Additionally, bacteria (Pasteuria) and fungi (Catenaria, Nematocida) feeding on N. lanceolatus are showed including light microscopy and scanning electron microscopy illustrations.