Proales ardechensis De Smet & Verolet 2009, n. sp.
Creators: name: De Smet, Willem H.
name: Verolet, Michel
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Rotifera
Eurotatoria
Ploima
Proalidae
Proales
Proales ardechensis

description: Proales ardechensis n. sp.
(Figs 1; 2)
TYPE MATERIAL. — All specimens from the type locality, collected 24.III.2007 and 8.VII.2008. Holotype: ♀ in a permanent glycerine glass slide mount (RBINS IG31125, RIR194). Paratypes: 38 ♀♀; 1 ♀ each in glass slide mount (RBINS RIR195), ANSP (Reg. N ° 1975) and MNHN (AM 878); 30 ♀♀ in glass slide mounts and 5 stubs each with one trophi preparation for SEM in UA.
TYPE LOCALITY. — Saint-Julien-du-Serre (4°25’0”E, 44°39’0”N), Ardèche, Rhône-Alpes, France.
ETYMOLOGY. — The species name ardechensis is derived from the area where the species was found.
DIAGNOSIS. — Stout fusiform animal with stout, long, c. ⅓ total length foot composed of four pseudosegments; penultimate foot pseudosegment with antenna dorsally near posterior margin. Pedal glands large with large reservoir, foot-length. Eyespots two colourless globules surrounded by dark-red granules, posteriorly between brain and mastax.Trophi malleate; rami with hook-shaped alulae; unci plate-shaped with 5 major teeth and 1-2/3 minor teeth.
DESCRIPTION OF FEMALE
Body broadly fusiform, stout (Fig. 1A, B). Head offset by neckfold; rostrum broad, short, truncate. Trunk ovate in dorsal view, offset from foot, in lateral view arched dorsally, more or less flattened ventrally; a short distal pseudosegment. Tail broad, truncate, less prominent.Foot long, c. ⅓ total length, stout, elongate conical; 4 pseudosegments, proximal pseudosegment shortest, the others equally long; penultimate pseudosegment with antenna (Fig. 1G) dorsally near posterior margin (often covered by posterior margin). Toes short, conical, very weakly decurved ventrally,appressed.Corona slightly oblique. Dorsal antenna near posterior third of head. Brain saccate. Retrocerebral sac absent.Subcerebral glands present. Eyespots (Fig. 1F) two colourless globules surrounded by a few dark-red granules, situated between brain and mastax, apparently not connected to posterior of brain. Between mastax and brain some individual cells apparently connected to brain. Lateral antennae small, near posterior third of trunk. Gastric glands large, spherical, latero-dorsal, ducts very short to absent. Stomach and intestine separated by shallow constriction. Pedal glands very large, ovate in lateral view, in dorsal/ventral view slightly compressed laterally, located in the two proximal foot pseudosegments, often extending into trunk, with large elongate reservoir in distal part of foot. Bladder normal. Vitellarium with eight nuclei.
Trophi malleate (Fig. 2). Incus almost perpendicular to body axis; axis of manubria parallel to body axis. Rami and fulcrum forming weak angle with each other; rami triangular with tips slightly recurved caudally, and an acute hook-shaped alula ventrally near lateral corner of rami; inner margins frontally with row of large projections, caudally a comb of appressed scleropili; basal apophyses a crest of appressed scleropili; fairly large triangular basifenestrae caudally, and large rounded sub-basifenestrae ventrally. Fulcrum half ramus length, plank-shaped, in lateral view parallel-sided, distal margin oblique bearing weakly developed basal plate. Unci a plate of firmly fused teeth; each uncus with 5 large teeth decreasing in size dorsally, and a set of 1 or 2 (left) or 3 (right) minor dorsal teeth; major teeth with small appressed preuncinal tooth; ventral margin of major tooth with small knob medially; subuncus a series of loosely bound scleropili. Manubria with well-developed, almost roundish head slightly longer than half manubrium length, showing 3 large openings, and stout, weakly curved shaft ending in slightly knobbed cauda. Epipharynx two ribbons of scleropili decreasing in length distally.
A single mictic female with resting egg inside was found in the sample of July. The resting egg (Fig.1D, E) is more or less ellipsoid and ornamented all-over with spiniform projections.
Male unknown.
Measurements
Total length 150-230 µm (mean 184 µm, N=15), toe 9-12 µm (mean 10 µm); trophi (N=4): ramus 11.5-14.1 µm, fulcrum 7.2-9.4 µm, uncus 10.2- 10.9 µm, manubrium 14.2-18.6 µm; resting egg 72 × 47 µm, spines 8-10 µm.
REMARKS
Although Proales ardechensis n. sp. keys out to P. sigmoidea (Skorikov, 1896) following the key by De Smet (1996), these two cannot be confused given the different trophi type: malleate in the new species and virgate in P. sigmoidea. Additionally the toes are conical in P. ardechensis n. sp. and more or less foliate in dorsal view in P. sigmoidea. The outer organization of P. ardechensis n. sp. resembles P. similis de Beauchamp, 1907, which however, has a single wrinkled foot pseudosegment without dorsal antenna, instead of four pseudosegments, the penultimate of which bearing an antenna dorsally. The trophi structure of both species is malleate, but P. ardechensis n. sp. differs mostly by its hookshaped alulae situated just below the lateral ramus corners, different from the straight alulae set at some distance from the lateral ramus corners of P. similis. Additional differences in trophi structure are the manubria with the more or less rounded head of half manubrium length, and the weakly curved shaft with knobbed cauda (head elongate triangular, about ⅔ manubrium length; shaft short with incurved cauda in P.similis), and the unci with 5 major teeth and 1-3 minor teeth (unci with 4 major teeth and 3 or 4 minor teeth in P. similis). Other species with similar external morphology, i.e. stout fusiform body with stout moderately long foot, are P.daphnicola Thompson, 1892 and P.kostei Nogrady & Smol, 1989, which however are unequivocally differentiated by the large characteristic basal rami apophyses.
ECOLOGY AND DISTRIBUTION
Proales ardechensis n. sp. was found in March and July, amongst wet mosses in the seepage area on a vertical rockface at a pH of 7.35 and water temperature of 7°C; the habitat usually dries up in summer. The accompanying rotifer fauna was dominated by bdelloids (Adineta sp., Dissotrocha sp., Henoceros falcatus (Milne, 1916), Pleuretra brycei (Weber, 1898)); the monogononts belonged to Cephalodella, Colurella, Lecane and Lepadella.
The species has to date only been recorded from the type locality. All freshwater records of the superficially similar P. similis, which is an inhabitant of inland saline, marine and brackish waters, are doubtful and may concern P. ardechensis n. sp.
description: Published as part of De Smet, Willem H. & Verolet, Michel, 2009, On two new species of Proales from France, with reallocation of Dicranophorus liepolti Donner, 1964 and D. secretus Donner, 1951 (Rotifera, Monogononta), pp. 959-973 in Zoosystema 31 (4) on pages 960-963, DOI: 10.5252/z2009n4a10, http://zenodo.org/record/4549148