Morphological and molecular characterisation of new and known species of Tripyla Bastian, 1865 (Triplonchida: Tripylidae) from northern Iran, with phylogenetic relationships, compendium and identification key

Abstract

During a nematological survey of the family Tripylidae, two new and two known species of the genusTripyla, namelyT. paraffinissp. n.,T. parafilicaudatasp. n.,T. glomeransandT. setifera, were identified and described from soil samples collected from the rhizosphere of forest trees in northern Iran. Three populations ofT. paraffinissp. n., found in different locations, are described and morphometric data of the type and other populations provided.Tripyla paraffinissp. n. is characterised by its body length of 1.21-1.89 mm, dorsal tooth wedge-shaped and triangular, short outer labial and cephalic sensilla, tail bent ventrad and gradually tapering to the end, horn-shaped spicules bearing a distinct constriction in the middle, and presence of 16-20 ventromedian supplementary papillae.Tripyla parafilicaudatasp. n. is described and illustrated from four different locations. It is characterised by females with a body length of 1.48-1.95 mm, dorsal tooth hook-shaped, vaginal wall with a downward pointing tooth-like projection in the middle, long outer labial and setiform cephalic sensilla, long tail, sausage-shaped spermatozoa, males with horn-shaped spicules and 11-17 ventromedian supplementary papillae.Tripyla glomeransandT. setiferaare new records for the Iranian nematofauna. The results of phylogenetic analyses based on sequences of the partial 18S and D2-D3 expansion segments of 28S rRNA fromT. paraffinissp. n. andT. parafilicaudatasp. n. and other species in the genus clearly support the proposal ofT. paraffinissp. n. andT. parafilicaudatasp. n. as new species, as well as indicating thatTripylashares a more recent common ancestor withTobrilus,Tripylella,Prismatolaimus,Diphtherophoraand two trichodorids,TrichodorusandParatrichodorus. The Tripylidae is placed in a main clade within the Triplonchida.