Stygepactophanes sp.1

Dole-Olivier, Marie-José, Galassi, Diana M. P., Fiers, Frank, Malard, Florian, Martin, Patrick, Martin, Dominique & Marmonier, Pierre, 2015, Biodiversity in mountain groundwater: the Mercantour National Park (France) as a European hotspot, Zoosystema 37 (4), pp. 529-550 : 539-540

Stygepactophanes sp.1

MATERIAL EXAMINED. — Site 30: 2 specimens, site 31: 3 specimens. Material deposited at UNIVAQ.

REMARKS

The genus Stygepactophanes was originally described by Moeschler & Rouch (1984) with the only species Stygepactophanes jurassicus collected from a karstic spring of the Swiss Jura. Since the formal establishment of this new canthocamptid genus, closely related to the genus Epactophanes Mrázek, 1893 , no other species were collected or described elsewhere. The genus Stygepactophanes is unique in showing several reductions and character losses in its body plan, such as the total absence of the leg 5 (P5) in both males and females, the body slender and only slightly sclerotized, and the reduction trends in the segmental pattern of the swimming legs, all derived characters which may be the result of heterochrony ( Galassi & De Laurentiis 2004a, b). A new species of this genus has been discovered in the Sanguinière spring (Mercantour), with females and copepodids having been found, but the male still missing. This new population shows unique features, which may place this undescribed species at the base of the evolutionary history that led to the more derived S. jurassicus . The new species, for instance, shows a very plesiomorphic P5, along with several other evolutionary novelties, which require an emended diagnosis of the genus (Galassi et al.). The genus is very rare, at present being known only from the type species from Switzerland and the undescribed species from Mercantour ( France). The extinction risk is very high and the genus as a whole should be considered critically endangered.

Family PARASTENOCARIDIDAE Chappuis, 1940