Enchodelus Thorne, 1939

Andrássy, Istvan, 2009, FREE-LIVING NEMATODES OF HUNGARY (NEMATODA ERRANTIA), Pedozoologica Hungarica III (5), pp. 382-387 : 382-385

Genus: Enchodelus Thorne, 1939

Syn. Rotundas Ahmad & Jairajpuri, 1980.

Diagnosis. Nordiidae , Pungentinae. Body length varying between 0.6 and 2.5 mm. Cuticle mostly smooth, rarely transversely annulated. Lips amalgamated or slightly separate, lip region slightly or strongly differentiated from adjoining body. Odontostyle very thin with small aperture, one to two labial diameters long; odontophore rod-like or more or less flanged. Guiding ring double, but usually low. Basal expanded part (cylindrus) shorter than half oesophagus length. Posterior nuclei (PS) as large as dorsal nucleus, lying far apart from posterior end of cylindrus. Posterior part of intestine often coloured (green). Prerectum usually long. Female genital system amphidelphic. Males generally rare. Spicula dorylaimoid, ventromedial supplements 7-16, spaced, posterior ones within the range of spicula. Tail in sexes similar, short and broadly rounded.

Type species. Dorylaimus macrodorus de Man, 1880 = Enchodelus macrodorus ( de Man, 1880) Thome, 1939 .

Main characters. Enchodelus is closely related to Heterodorus Altherr, 1952 , but the hemispherical tail and the number and arrangement of the supplements (posterior ones always lying within the range of the spicula) simply distinguish it from that genus.

Remarks. When Siddiqi (1969) raised Nordiinae to a family rank, he also proposed the subfamily Pungentinae and placed Pungentus and Enchodelus under it. Ahmad and Jairajpuri (1980) provided a revision of the genus Enchodelus and grouped the species in five subgenera: Enchodelus , Rotundus , Heterodorus , Nepalus and Paraenchodelus . They distinguished these subgenera by the length of the odontostyle, presence or absence of odontophore flanges, and by the shape of the tail, but the “differences” showed overlaps. At the same time, the Indian authors underlined that Enchodelus essentially contains two distinct groups of species, one with conoid tails, and another with rounded tails. Vinciguerra (1976) agreed with this view.

I am also of the opinion that the old genus Enchodelus may be divided into two large natural groups. Species of one group possess broadly rounded tail and supplements beginning within the range of the spicula, while the species of another group possess conoid tail and supplements beginning well before the spicula. The former represent the genus Enchodelus (s. str), and the latter the genus Heterodorus (see there).

The representatives of Enchodelus mostly inhabit terrestrial biotopes and are par ­ ticularly frequent in mosses. They feed on plants, predominantly on mosses, and the pos ­ terior part of their intestine is often dark green by clorophyll. They are widely distrib ­ uted in the northern hemisphere. Enchodelus currently contains 23 valid species.

E. altherri Vinciguerra & De Francisci, 1973

E. ameliae Guerrero, Liebanas & Pena-Santiago, 2008

E. analatus (Ditlevsen, 1927) Thome, 1939

E. arcticus Nesterov, 1976

E. distinctus Ahmad & Jairajpuri, 1980

E. georgiensis Eliava, Tskitishvili & Bagaturia, 2006

E. groenlandicus (Ditlevsen, 1927) Thorne, 1939

E. hopedoroides Altherr, 1963

E. hopedorus (Thome, 1929) Thome, 1939

E. laevis Thome, 1939

E. longispiculus Guerrero, Liébanas & Peña-Santiago, 2008

E. lucinensis Popovici, 1978

E. macrodorus ( de Man, 1880) Thorne, 1939

E. microdoroides Baqri & Jairajpuri, 1974

E. montanus Bagaturia, Eliava & Eliashvili, 1979

E. parateres Baqri & Jairajpuri, 1974

E. parvus Loof, 1971

E. ponorensis Popovici, 1995

E. saxifragae Popovici, 1995

E. signyensis Loof, 1975

E. teres Thorne, 1939

E. vestibulifer Altherr, 1952

E. vesuvianus (Cobb, 1983) Thorne, 1939

The following species are synonym or inquirenda.

E. hedickei (Pacsler, 1941) Andrassy, 1960 - inq.

E. kuppenburgensis Altherr in Altherr & Delamare Deboutteville, 1972 = E. laevis

Europe is inhabited by fifteen species ( altherri , ameliae , analatus , groenlandicus , hopedoroides , hopedorus , longispiculus , lucinensis , macrodorus , parvus , ponorensis , saxifragae , teres , vestibulifer and vesuvianus ), Hungary by three.

Etymology. The genus name is originated from the Greek enchos (eyxog) = a lance or spear.

Key to European species of Enchodelus

1 Odontostyle 28-40 μm long............................................................................................2

- Odontostyle 25 μm or shorter ....................................................................................... 8

2 Body 2.0-2.5 mm long.................................................................................................... 3

- Body 1.2-1.8 mm long.................................................................................................... 4

3 Body 2.0-2.3 mm .............................................................. saxifragae Popovici , 199526

- Body 2.5 mm ............................................................ groenlandicus (Ditlevsen, 1927)

4 Odontostyle 38-12 μm long; vulva at 40-44% ....................... macrodorus (p. 386)

- Odontostyle 28-34 μm long; vulva at 44-57% ...........................................................5

5 Odontostyle as long as two labial diameters ............................................................... 6

- Odontostyle shorter than two labial diameters ............................................................. 7

6 Lip region offset by constriction; total stylet about 70 μm long ................................ ..................................................... ameliae Guerrero, Liébanas & Peña-Santiago, 2008

- Lip region offset by slight depresion; total stylet about 80 μm long .......................... ............................................................................................. analatus (Ditlevsen, 1927)

7 Tail 17-29 μm long .... longispiculus Guerrero, Liébanas & Peña-Santiago, 2008

- Tail 27-39 μm long ............................................................ hopedorus (Thome, 1929)

8 Very small species, 0.6-0.8 mm ..................................................... parvus Loof, 1971

- Larger species, mostly well over 1 mm ........................................................................9

9 Odontostyle two labial diameters long ............................ hopedoroidesAltherr, 1963

- Odontostyle one and a half labial diameters long ..................................................... 10

10 Lips rounded ...................................................................................................................11

- Lips angular ...................................................................................................................13

11 Body longer, 1.6-2.1 mm and slender (a = 30-40)........ ponorensis Popovici, 1995

- Body shorter, 1.1-1.6 mm and more robust (a = 20-27).......................................... 12

12 Ventromedial supplements 7 -9 ............................................................. altherri (p. 385)

- Ventromedial supplements 10-11 .................................................. vesuvianus (p. 386)

13Tail half anal body width long .................................... lucinensis Popovici, 1978

- Tail one anal body width long ..................................................................................... 14

14 Tail hemispherical ............................................................................ teres Thome, 1939

- Tail more conoid-rounded ..................................................... vestibulifer Altherr, 1952