Proales laticauda, De Smet & Verolet, 2009

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), Zoosystema 31 (4), pp. 959-973 : 963-966

Proales laticauda n. sp.

( Figs 3 ; 4 )

TYPES. — All specimens from the type locality and collected 12.V.2008.

Holotype: parthenogenetic ♀ in a permanent glycerine glass slide mount ( RBINS IG31125 , RIR196 ).

Paratypes: 16 ♀♀; 1 parthenogenetic ♀ each in glass slide mount in RBINS (Reg. N ° RIR197), ANSP (1976) and MNHN ( AM 879 ) ; 8 ♀♀ in 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 laticauda is derived from the Latin adjective latus, broad, and the noun cauda, tail, in reference to the large tail.

DIAGNOSIS. — Body cylindrical; foot short, two pseudosegments, almost completely covered by large and broad truncate tail. Toes small and slender, swollen basally. Trophi malleate; rami with short spiniform alulae; unci plate-shaped with 4 or 5 major teeth and 1-3 minor teeth.

DESCRIPTION OF FEMALE

Body ( Fig. 3A, B ) almost cylindrical in dorsal view, in lateral view dorsal and ventral margin of trunk weakly arched. Head offset by neckfold; rostrum small, rounded; a transversal dorsal fold at ⅓ from top. Trunk long, without obvious pseudosegments except for its distal part; anterior ⅔ with faint longitudinal folds dorsally. Tail ( Fig. 3C, D ) large and broad, truncate distally, almost covering foot completely. Foot with very small and narrow distal pseudosegment and a much broader penultimate pseudosegment. Toes very small, swollen till mid-length, narrowing and tapering afterwards, in lateral view weakly decurved ventrally. Corona oblique, two small lateral tufts of longer cilia. Dorsal antenna medially on first head pseudosegment. Brain saccate. Retrocerebral sac small, clear. Two colourless globules (eyespots?) laterally at base of rostrum. Lateral antennae not seen. Mastax spherical. Stomach cellular, separated from intestine by constriction; a small proventriculus present. Gastric glands large, spherical, ducts apparently absent. Pedal glands small, club-shaped. Bladder normal. Vitellarium with 8 nuclei.

Trophi malleate ( Fig. 4 ). Incus almost perpendicular to body axis; axis of manubria parallel to body axis. Rami and fulcrum forming weak angle with each other. Rami triangular, tips weakly recurved caudally, short spiniform alulae somewhat ventrally below lateral rami corners; inner margins with row of stout projections frontally; basal apophyses a crest of stout appressed scleropili; basifenestrae caudal, triangular; sub-basifenestrae ventral, rounded, moderately large. Fulcrum fairly long, in lateral view tapering distally. Unci a plate of firmly fused teeth; each uncus with 4 or 5 large teeth decreasing in size dorsally, and set of 1-3 (left) or 1 or 2 (right) minor dorsal teeth; major teeth with a small preuncinal tooth and a small knob at ⅓ of ventral margin; head of major teeth distinctly offset with small lateral knobs at base. Manubria with long triangular head, short shaft and weakly incurved cauda; dorsal opening of head small, medial and ventral openings large.Epipharynx two long, distally tapering ribbons of appressed scleropili.

Male unknown.

Measurements

Total length 113-141 µm (mean 130 µm, N=15), toe 11-14 µm (mean 12 µm); trophi (N=3): ramus 7.0- 7.2 µm, fulcrum 5.6-6.3 µm, uncus 6.9-7.7 µm, manubrium 10.6-12.3 µm.

REMARKS

Proales laticauda n. sp. can hardly be confused with any congener. Applying the key by De Smet (1996) and assuming that the colourless globules at the base of the rostrum are eyespots, the new species does not key out. On the other hand, accepting that eyespots are absent leads to P. cryptopus Wulfert, 1935 and P. macrura Myers, 1933 . Both species have a cylindrical body and large tail covering foot and toes completely or almost completely. The large (375 µm) P. cryptopus differs from the smaller (~ 130 µm) P. laticauda n. sp. by the very short (1/34 total length) conical toes (toes small, swollen till mid-length, tapering distally in P. laticauda n. sp.), the elongate gastric glands with acute ends (glands spherical in P. laticauda n. sp.) and the red cerebral eyespot (? eyespots absent or two colourless rostral globules in P. laticauda n. sp.). The likewise small (150 µm) P. macrura is distinguished from the new species by the almost ventral corona (corona oblique in P. laticauda n. sp.), the cerebral eyespot, the ventrally placed tubular foot (foot with small distal and broad penultimate pseudosegment in P.laticauda n. sp.), and short toes with slightly swollen bases. Both P. cryptopus and P. macrura have malleate or modified malleate trophi differing from those of P.caudata n. sp., but lack of detail of the descriptions and figures based on light-microscopic observations do not allow for a direct comparison.

ECOLOGY AND DISTRIBUTION

Proales laticauda n. sp. was collected in a fire-wood from aerophytic moss growing on sandstone. It was accompanied by Mniobia sp., Habrotrocha sp.and other unidentified bdelloids, and the monogononts Aspelta secreta and Colurella sp. To date the new species has only been recorded in May from the type locality.

Figures

FIG. 3. — Proales laticauda n. sp.,female:A, lateral view;B, dorsal view; C, detail of foot, toes and tail, lateral view; D, detail of foot, toes and tail, dorsal view. Scale bars: A, B, 50 μm; C, D, 10 μm.

FIG. 4. — Proales laticauda n. sp., SEM photographs of trophi: A, incus and unci, frontal view; B, complete set, incus dorso-caudal view, manubria and unci inner view; C, left manubrium, outer view; D, incus and unci, lateral view; E, complete set, ventro-apical view. Scale bar: 10 μm.