Prochromadora Filipjev, 1922

Venekey, Virag, Gheller, Paula F., Kandratavicius, Noelia, Cunha, Beatriz Pereira, Vilas-Boas, Ana Carolina, Fonseca, Gustavo & Maria, Tatiana F., 2019, The state of the art of Chromadoridae (Nematoda, Chromadorida): a historical review, diagnoses and comments about valid and dubious genera and a list of valid species, Zootaxa 4578 (1), pp. 1-67 : 14-15

Genus Prochromadora Filipjev, 1922

This genus was established with P. orleji (de Man, 1880) as the type species ( Filipjev, 1922) and it is unique within Chromadorinae in having homogenous cuticle without transversal rows of dots or lateral differentiation. Filipjev (1930) reviewed the genus and transferred three species from Chromadora to Prochromadora : P. orleji , P. erythrophthalma and P. minor . These latter two species were regarded as Chromadorina in the review of Wieser (1954), who also transferred Chromadorita and Chromadora species to Prochromadora [ P. magna ( Schulz, 1935) and P. exigua ( Ditlevsen, 1928) , respectively]. In this review, a key based on the length of nematodes was also proposed, in which P. magna is distinguished from the other species based on its relatively large body length (2- 2.5mm). Tarjan et al. (1991) redescribed P. orleji and proposed a key for the nine species valid at that time. Based on this key, males of this genus can be easily separated in two groups based on the presence ( P. argentinensis Pastor de Ward, 1984 ; P. exigua ; P. megodonta Filipjev, 1922 ; P. orleji ; P. spiltzbergensis Gerlach, 1965 and P. trisupplementa Murphy, 1963 ) and absence ( P. asupplementa Hopper, 1961 and P. bulbosa Galtsova, 1976 ) of precloacal supplements. When precloacal supplements are present they can range from 3 to 20. P. helenae was the most recent species described in this genus by Tchesunov (2015) and it can be included in the group of species without precloacal supplements.

Diagnosis (modified from Tchesunov 2014): Homogeneous punctated cuticle without transversal rows of dots and without lateral differentiation. Amphideal fovea transverse slit-like, but not visible in several species. Single large dorsal tooth opposed by a ventrosublateral pit or at most by a small elevation of the buccal wall or small ventrosublateral teeth. Posterior pharyngeal bulb well developed. Precloacal supplements usually present in males. It is mainly marine genus, but C. orleji is also recorded in freshwater.

Number of valid species: 10

Genus Prochromadora Filipjev, 1922

VALID SPECIES

1. Prochromadora argentinensis Pastor de Ward, 1984 (Puerto Deseado, Argentina)

2. Prochromadora asupplementa Hopper, 1961 (Alabama, USA)

3. Prochromadora bulbosa Galtsova, 1976 (White Sea)

4. Prochromadora exigua ( Ditlevsen, 1928) Wieser, 1954 ( Greenland)

Syn. Chromadora exigua Ditlevsen, 1928

5. Prochromadora helenae Tchesunov, 2015 (Mid-Atlantic Ridge)

6. Prochromadora magna ( Schulz, 1935) Wieser, 1954 (Mediterranean)

7. Prochromadora megodonta Filipjev, 1922 (Black Sea)

8. Prochromadora orleji (de Man, 1880) Filipjev, 1922 (North Sea)

Syn. Chromadora orleji de Man, 1880

9. Prochromadora spitzbergensis Gerlach, 1965 ( Svalbard)

10. Prochromadora trisupplementa Murphy, 1963 (Oregon, USA)