Paradicranophorus halophilus, De Smet, Willem H., 2015

De Smet, Willem H., 2015, Rotifera from the Mediterranean Sea, with description of ten new species, Zootaxa 4028 (2), pp. 151-196 : 170-171

Paradicranophorus halophilus sp. nov.

( Figs 14 , 15 )

Diagnosis. Female 200-240 µm. Trunk with 5−6 conspicuous transversal, and several longitudinal folds; foot almost caudal; lateral antennae fairly long, near posterior 1/3 of trunk; intramallei and supramanubria present; rami outline elliptical-oboval; median rami opening more or less oblong-oval; inner margins of rami with tooth prior to apical ramus tooth. Oviparous.

Type locality. Scoglietto di Portoferraio, Elba Island, Tyrrhenian Sea, Italy. In psammon collected on 30.09.2006, 1 km off shore and depth of 35 m; water temperature 23 °C.

Holotype. A female in a permanent, glycerine glass slide mount deposited in the Royal Belgian Institute of Natural Sciences ( RBINS), Brussels, Belgium, No. IG 33082, RIR 222.

Paratypes. One female from type locality in RBINS, No. IG 33082, RIR 252; 5 mounted paratypes and 3 SEM trophi preparations in Department of Biology, University of Antwerp.

Additional material. Several specimens from sublittoral of Costa Blanca, Costa Brava, Côte d’Azur, and Elba Island (see Tab. 2 species list).

Etymology. The name of the species is a Latinization of the Greek hals, salt, and philos, friend, referring to the environment inhabited by the species.

Description of female. Body cylindrical ( Figs 14 A −C); trunk weakly widening towards rounded posterior; head slightly broader than neck, distinctly offset by neckfold; in lateral view trunk almost as high throughout; rostrum narrow, bluntly triangular. Trunk with some 5−6 conspicuous transversal and several longitudinal folds; on contraction usually two deep furrows near mid-length. Tail absent. Foot almost caudal, two pseudosegments; large penultimate segment continuous with trunk, distal pseudosegment small, indistinctly offset. Toes ( Figs 14 E −I) fairly short, almost straight, slightly indented behind base, tapering to acute points. Dorsal antenna near middle of head. Lateral antennae ( Fig. 14 D) fairly long, near posterior 1/3 of trunk. Two frontal colourless eyespots at base of rostrum. Gastric glands fusiform, stalked. Pedal glands fusiform with reservoir at base of toes. Vitellarium with 8 nuclei. Oviparous.

Trophi ( Figs 14 J, 15) elongate. Outline of rami elliptical to oboval; inner margins of rami with tooth prior to robust apical rami teeth; apical rami teeth oblique, tip offset; outer margin of rami with rounded expansion prior to apical tooth whereupon dorsal rib of shaft of unci rest; median rami opening more or less oblong-oval; basifenestrae and subbasifenestrae small, rounded. Fulcrum short, lamelliform, broadly rounded distally. Unci single-toothed; shaft as long as head, with well developed dorsal rib. Each ramus with single stout preuncinal tooth; head somewhat longer than shaft. Intramallei small, with more or less semi-lunar supramanubria. Manubria rodshaped, weakly curved; head reduced, with latero-ventral opening.

Measurements. Body (N=5): total length 200‒240 µm, toe 28‒33 µm, lateral antenna 4.5‒5.0 µm; trophi (N=3): length 28−29 µm, ramus 12.7‒14.1 µm, fulcrum 4.2‒4.5 µm, uncus 9.0‒9.9 µm, preuncinal tooth 6.1‒6.5 µm, intramalleus 1.7 × 1.3 µm, supramanubrium 5.0‒6.0 µm, manubrium 19.2‒20.8 µm.

Comments. Paradicranophorus halophilus sp. nov. is easily distinguished from its six described congeners, by the presence of a tooth on the inner margins of the rami. The new species shares the characters presence of intramallei and supramanubria with P. sordi dus Donner, 1968 , P. wesenberglundi Sørensen, 2001 , and P. s i n us De Smet, 2003.

Distribution and ecology. Paradicranophorus halophilus sp. nov. is one of the most frequently encountered species, often occurring in considerable numbers. It was found in the sublittoral psammon samples from the Costa Blanca, Costa Brava, Côte d’Azur, and Elba Island, Tyrrhenian Sea, at distances of 50 m to 3.5 km from the shoreline, and depths between 15 and 40 m. It was present in samples of June, July, August, September, and October, at water temperatures of 16−24 °C.

Figures

FIGURE 14. Paradicranophorus halophilus sp. nov. A. Female, ventral; B. female, lateral; C. female, dorsal; D. lateral antenna; E − H. toes, lateral; I. toe, dorsal; J. trophi, dorsal. Scale bars: A − C: 50 µm; D − J: 10 µm.

FIGURE 15. Paradicranophorus halophilus sp. nov., SEM photographs of trophi. A. Complete set, dorsal; B. detail, dorsal; C. detail, ventral; D. detail, dorso-frontal. Scale bars: 10 µm.