Key to the free-living marine Nematoda Key created by Maaike Steyaert Please refer to this identification key as Steyaert et al. 2005. Electronic Key to the free-living marine Nematodes. World Wide Web electronic publication. www.nemys.ugent.be. 09/2005 Restart from Nematoda | Restart Completely | Select different key | Show legend

Characteristics  amphid presence        present       absent       absent or faintly visible  amphid shape         circular       elongated loop       unispiral       multispiral       pocket like       slit like       other       not applicable       longitudinal slit       amphid on plaque       large bladder-like       amphid with internal cuticularised opening       transverse oval       amphid with elongated corpus gelatum       horse-shoe shaped       rounded loop       oval loop       rounded spiral       longitudonal oval       faintly visible  anterior oesophageal bulb presence        present       absent  body length (adults)         < 0.5 mm       0.5 - 1 mm       1 - 2 mm       2 - 3 mm       3 - 4 mm       4 - 5 mm       9 - 10 mm       > 10 mm       5 - 6 mm       6 - 7 mm       7 - 8 mm       8 - 9 mm  body shape         fusiform       short fat       S or E shaped  buccal cavity shape        big       reduced       small       cylindrical       elongated       conical       with stilet       cup-shaped       other  cuticle pattern        smooth       coarsely striated, resembling annulations       finely striated       with transverse rows of dots       with longitudinal rows of structures       with conspicuous transverse rings (desmen) or rows or spines       with longitudinal ridges       with lateral differentiation       smooth, covered with sediment / detritus  denticles presence        present       absent  division of buccal cavity        not applicable       1 compartiment       2 compartiments or sections       more compartiments or sections  gubernaculum shape (males)        distally dentate       not applicable       other       with lateral pieces  head capsule presence         absent       present  mandibles presence        present       absent  mid oesophageal bulb presence        1 mid bulb present       absent       more than 1 mid bulb present  oriëntation of gubernaculum        dorso-caudal or caudal       in line with spicules  posterior oesophageal bulb presence        present       absent       more than 1 bulbus  posterior oesophageal bulb shape        not applicable       other       spherical       double bulbus       with cuticular lining       elongated       oval  precloacal supplements presence (males)        present       absent  precloacal supplements type (males)        tubular       not applicable       other       papilliform       setiform       cup-shaped  presence of copulatory bursa around cloaca        present       absent  spicules and gubernaculum presence (males)        only spicules       only gubernaculum       both spicules and gubernaculum  tail shape        short and blunt       elongated, filiform       other       conico-cylindrical       conical       conico-cylindrical with swollen tip

Remaining taxa:    Anticomidae, Ironidae, Anoplostomatidae, Tripyloidina and some other genera (fig 18)    Axonolaimidae, Diplopeltidae, Haliplectidae, Bodonematidae and some other genera (fig 23)    Chromadoridae (part 1) (fig 35) Filipjev, 1917    Chromadoridae (part 2) (fig 36) Filipjev, 1917    Cyatholaimidae (fig 31) Filipjev, 1918    Cyatholaimidae (fig 32) Filipjev, 1918    Desmoscolecidae (fig 12) Shipley, 1896    Diplopeltidae, Tubolaimoididae, Aegialoalaimidae and Siphonolaimidae (fig 24)    Enchelidiidae (fig 21) Filipjev, 1918    Enoplidae, Thoracostomopsidae, Anoplostomatidae and Tripyloididae (fig 19)    Epsilonematidae and Draconematidae (fig 13)    Ethmolaimidae (fig 33) Filipjev & Schuurmans Stekhoven, 1941    Leptolaimidae, Lauratonematidae and Peresianidae (fig 22)    Leptosomatidae and Phanodermatidae (fig 17)    Linhomoeidae and Xyalidae (part 4) (fig 25)    Meyliidae, Microlaimidae, Desmodoridae and Aponchidae (fig 29)    Monhysteridae, Xyalidae (part 1) and Sphaerolaimidae (part 1) (fig 26) Nematoda - fig 30    Oncholaimidae (fig 20) Filipjev, 1916    Selachinematidae (fig 34) Cobb, 1915    Tripyloididae, Trefusiidae and Oxystomina (fig 16)    Xyalidae (part 2) and Spaerolaimidae (part 2) (fig 27 ) Filipjev, 1918    Xyalidae (part 3), Monoposthiidae and Ceramonematidae (fig 28)