Doryphoribius citrinus ( Maucci, 1972 )

Lisi, Oscar, 2011, Remarks on Doryphoribius flavus (Iharos, 1966), and description of three new species (Tardigrada, Hypsibiidae), Zootaxa 2834, pp. 17-32 : 20

Remarks on Doryphoribius citrinus ( Maucci, 1972)

Material examined. Holotype and five paratypes; the holotype and two paratypes deposited in the Maucci collection, “Museo Civico di Storia Naturale di Verona”, slide numbers not available; three paratypes deposited in the Binda and Pilato collection, Museum of the Department of Animal Biology “Marcello La Greca”, slide number 1200; according to Maucci, 1972, the specimens were extracted from moss on a calcareous stone wall exposed to the South, in a sunny area very close to the traffic circle “Pazin-Rjeka” of the suburbs of Gračišće, Istria.

Though not very good condition, the material was better preserved than that of D. flavus so the reticulate sculpture was clearly visible ( Fig. 2 A). It consisted of ridges only slightly variable in width, usually narrow, delimiting a mesh that was rather variable in shape and size (up to 11.8 μm - pt = 20.3 - in a specimen 486.9 μm long). Tubercles were not formed at crossings, although the intersections may sometimes be enlarged. The mesh increased in average size from the lateral to the dorsal cuticle and from the head to the posterior portion of the body, reaching a maximum diameter between the third and the fourth pair of legs, and decreasing slightly in diameter more caudally.

The smooth swollen portions of the legs were visible, and a faint dense reticulation was visible on the external side of the first three pairs of legs, as reported by Maucci (1972).

The buccal tube appeared rather slender ( Fig. 2 B), dorsal teeth were present in the buccal cavity ( Fig. 2 C), arranged dorso-laterally, as in the paratypes of D. flavus ; ventral teeth were not visible ( Fig. 2D ); peribuccal papulae present, some of which were divided. Neither the buccal cavity teeth nor the peribuccal papulae were mentioned in the original description ( Maucci, 1972), and have not previously been reported. The other characters of the bucco-pharyngeal apparatus match both those observed in the type material of D. flavus and those reported in Maucci, 1972.

Claws, like those of the paratypes of D. flavus , of the Isohypsibius type ( Fig. 2 E), differing in shape and size on each leg; basal portions of the external claws clearly wider than those of the internal ones, accessory point and lunules present. Again, like the paratypes of D. flavus , the lunules of the inner claws ( Fig. 2 F) have not previously been noticed. No other sclerified structures visible on legs.

Figures

FIGURE 2. D. citrinus. A, Cuticular sculpture of the caudal portion of a paratype; B, Anterior portion of the body of another paratype; C, Bucco-pharyngeal apparatus of a third paratype in dorsal view: the dorso-lateral teeth of the buccal cavity are visible (arrows); D, Bucco-pharyngeal apparatus in ventral view of the same paratype as Fig. 2 C; E, Claws of the second and third pairs of legs of a fourth paratype; F, detail of E showing the very narrow lunule (arrow) at the base of an inner claw of the third pair of legs (the lunule of the external claw is not in focus). Scale bar = 10 µm.