Revision of Desmodorinae and Spiriniinae (Nematoda: Desmodoridae) with redescription of eight known species

Abstract

The taxonomy of the family Desmodoridae (Nematoda: Desmodorida) is partially revised based on morphology. The diagnoses of the Desmodoridae and the subfamilies Desmodorinae and Spiriniinae are emended to accommodate re-analyzed morphological features. Eight known species are redescribed and the implication of the new findings for the taxonomy of the group is discussed. Amphispira and Metadesmodora are confirmed as genera inquirendae. Alaimonema and Sigmophoranema, and their corresponding type species, are proposed as inquirendae due to poor descriptions of the type material. The other three species of Sigmophoranema are transferred to the genus Onyx because they bear the diagnostic features of this group: spear-like dorsal tooth and s-shape precloacal supplements. Echinodesmodora, Paradesmodora and Stygodesmodora are transferred to the Spiriniinae based on the absence of a head capsule and on the amphidial fovea being surrounded by cuticle striation. Paradesmodora toreutes is transferred to the genus Acanthopharyngoides as A. toreutes comb. nov. The genus Onepunema does not fit in the family Desmodoridae because of diorchic males; thus, it is regarded as taxon incertae sedis. Lists of valid genera for the two subfamilies are provided. A dichotomic key for the identification of the 14 genera within the Spiriinae is provided.

New Spirinia and Stygodesmodora species (Nematoda, Spiriniinae) from the Southwest Pacific, and a revision of the related genera Spirinia, Chromaspirina and Perspiria

“…The name has the same authorship and date at every rank." The appropriate authorship for Spiriniinae should therefore be attributed to Chitwood (1936), and not Gerlach & Murphy (1965), as is often done (e.g., Armenteros et al 2014).…”

“…Valid genera Armenteros et al 2014) Alaimonema Cobb, 1920Chromaspirina Filipjev, 1918Metachromadora Filipjev, 1918Onyx Cobb, 1891Papillonema Verschelde et al, 1995Paradesmodora Schuurmans Stekhoven, 1950Parallelocoilas Boucher, 1975Perspiria Wieser & Hopper, 1967Polysigma Cobb, 1920Pseudometachromadora Timm, 1952Sigmophoranema Hope & Murphy, 1972Spirinia Gerlach, 1963Spirodesma Cavalcanti et al, 2009Stygodesmodora Blome, 1982 We provide emended diagnoses and updated lists of valid species for Chromaspirina, Spirinia, and Perspiria below to clarify the distinctions between them. These lists are based on the original and any subsequent descriptions; as many of the original descriptions (especially early ones) lack type material, we often had to rely on short descriptions and/or illustrations.…”

DNA Barcoding for Delimitation of Putative Mexican Marine Nematodes Species

“…This study contributes to the current knowledge of the diversity and distribution of meiofaunal marine nematodes in Mexico. The faunistic information in Mexico, and Central America, in general, is traditionally scarce, reflecting the low number of taxonomic experts in the area [80]. Until now, a total of 183 species of marine nematodes are known for Mexico, of which seven have type locality in Mexico [16,22,26,81,82].…”

“…The report of Desmodoridae taxon is particularly relevant. This family is globally represented with a high number of species (320 species) [80]. Nevertheless, genetic sequence records for this family are scarce compared with the number of species described [80].…”

“…Here, we add 20 COI new sequences from Desmodoridae taxa. However, species identification based only on morphology was particularly tricky due to the lack of well-defined diagnostic traits, weak taxonomic keys reference, and absence of updated databases, including species lists [43,47,80].…”