Cervonema Wieser, 1954

Leduc, Daniel, 2012, Deep-sea nematodes (Comesomatidae) from the Southwest Pacific Ocean: five new species and three new species records, European Journal of Taxonomy 24, pp. 1-42 : 3

Genus Cervonema Wieser, 1954

Diagnosis (modified from Chen & Vincx (2000))

Sabatieriinae . Body cuticle striated, without punctations; cervical region elongated or short. Six external labial sensillae setiform, usually almost equal in length to four cephalic setae. Amphideal fovea with 4-8 turns. Buccal cavity small, without teeth. Spicules simple, gubernaculum small or absent, minute precloacal supplements present or absent.

Type species

Cervonema allometricum Wieser, 1954

Remarks

Interspecific variation in the morphological characters of Cervonema species is relatively limited, and species within this genus should be identified using as many characters as possible (e.g., Barnes et al. 2012). The following characters, however, are particularly useful in species identification: relative length of outer labial setae and cephalic setae, shape and position of amphids, shape and size of spicules, presence/ absence and shape of gubernaculum, and tail length. Other traits, which have not always been included in earlier species descriptions, include presence/absence of jointed outer labial setae and presence /absence of sperm dimorphism. Pre-cloacal supplements are often difficult to observe using light microscopy and should not be used in isolation for defining species.