Trefusialaimus Riemann, 1974

Leduc, Daniel, Zhao, Zeng Qi & Sinniger, Frederic, 2020, Halanonchus scintillatulus sp. nov. from New Zealand and a review of the suborder Trefusiina (Nematoda: Enoplida), European Journal of Taxonomy 661 (661), pp. 1-45 : 18

Genus Trefusialaimus Riemann, 1974

Diagnosis (modified from Riemann 1974)

Trefusiinae . Cuticle smooth. Sub-cephalic and somatic setae absent. Four jointed cephalic setae and six jointed outer labial setae in one circle; amphid pocket-shaped. Buccal cavity minute, funnel-shaped, not cuticularized. Male with one anterior outstretched testis (monorchic) and peri-cloacal papillae. Elongated sperm cells with central rod and light-refractive nucleus at one extremity. Female reproductive system (known only for T. idrisi ) with two opposed and outstretched ovaries. Tail conico-cylindrical or filiform. Three species.

Type species

Trefusialaimus monorchis Riemann, 1974 .

Other valid species

T. magnus ( Filipjev, 1946) Riemann, 1974 .

= Trefusia magna Filipjev, 1946 .

T. idrisi Leduc, 2013 .

Remarks

Trefusialaimus and Tripylina are the only genera of the suborder Trefusiina characterized by having the outer labial sensilla and cephalic setae in a single circle. This character agrees with the diagnosis of the Tripyloidina ; however, Trefusialaimus differs from the latter in the absence of metanemes (vs metanemes sometimes present in Tripyloidina ), and in having pocket-shaped amphids (vs spiral amphids in Tripyloidina ) and a toothless buccal cavity (vs teeth common in Tripyloidina ). The current placement of Trefusialaimus within the Trefusiinae , which follows Riemann (1974) and Lorenzen (1981, 1994), is only tentative and may need to be revised as suggested by SSU phylogenetic analyses (present study).