Doryphoribius solidunguis, Lisi, Oscar, 2011

Lisi, Oscar, 2011, Remarks on Doryphoribius flavus (Iharos, 1966), and description of three new species (Tardigrada, Hypsibiidae), Zootaxa 2834, pp. 17-32 : 28-31

Doryphoribius solidunguis sp. nov.

( Fig. 5 )

Material examined. Holotype (slide number 3796), 37 paratypes and 12 exuviae with eggs (slide numbers 3785- 3796, 4179, 4180) mounted in polyvinyl lactophenol; Bali: Tampaksring, from a moss sample (data available from Pilato & Binda, 1990).

Specific diagnosis. [Eye spots present*], very evident reticulate sculpture on dorsal and lateral cuticle forming mesh that was quite irregular in shape and size, delimited by ridges of various width (some very wide); the ridges were often rather protruding, only sometimes forming tubercles at crossings. Anterior sides of the first three pair of legs and posterior side of the fourth pair of legs, swollen; legs smooth. Bucco-pharyngeal apparatus of the Doryphoribius type; peribuccal papulae present, some of which were divided. Two pairs of dorsal teeth in the buccal cavity, difficult to see, along the anterior margins of the stylet sheaths. Two macroplacoids and no microplacoid or septulum in the pharyngeal bulb. Claws of the Isohypsibius type, large and stout, with very small accessory points on the main branches; external claws with wide basal portion enlarged at the very base; internal claws with smaller basal portion; evident smooth lunules present. A cuticular bar partially divided into dots was present beside the base of the internal claws of the first three pairs of legs. Smooth eggs laid into the exuvium.

[*] = Not visible after mounting in polyvinyl lactophenol.

Description of the holotype. Unfortunately the mounting media had caused contraction to a greater of lesser extent in many of the specimens. I have therefore designated as the holotype a specimen that best shows the most important characters of the species.

It was not possible to correctly measure body length (probably about 380 µm) but in Table 4 the correct measurements are provided of a paratype; eye spots no longer visible; dorsal and lateral cuticle ornamented with ridges, often protruding and wide (especially those of the medial-dorsal cuticle), which formed a reticular design with mesh of various shape and size ( Fig. 5 A in a paratype); the average size of the mesh increased from the lateral to the dorsal cuticle and from anterior to the posterior portion of the body, reaching the maximum between the third and the fourth pairs of legs (largest mesh about 7.3 µm; pt index 16.7) and decreased more posteriorly. On some crossings a tubercle could be seen, on others it was clearly absent, while in other cases the protruding ridges made it difficult to discern whether a tubercle was present or not. Due to the orientation of the specimen in the slide, the swollen portions (anterior for the first three pairs, posterior for the fourth pair of legs) were not visible but were in the paratypes. Cuticle of the legs smooth.

Holotype Slide N. 3796 Smallest paratype Slide N. 3796 Largest paratype Slide N. 3796 Characters µm pt % bo-le µm pt % bo-le µm pt % bo-le III ex. claws 25.8 59.2???? 21.8? 52.9? 6.0? III int. claws 21.8 50.0??????? Bucco-pharyngeal apparatus of the Doryphoribius type ( Fig. 5 B); peribuccal papulae present, some of which were divided; buccal armature consisted of only two pairs of dorsal teeth ( Fig. 5 C, arrow), difficult to see, along the anterior margin of the stylet sheaths. Buccal tube 43.6 µm long and 5.9 µm wide (pt = 13.5), stylet supports inserted on the buccal tube at 70.0 % of its length (pt = 70.0); ventral lamina 25.4 µm long (pt = 58.3). Pharyngeal bulb could not be measured, with apophyses and two macroplacoids; no microplacoid or septulum present; placoid row 15.2 µm long (pt = 34.9), first macroplacoid slightly constricted in the middle, 8.5 µm long (pt = 19.5), second one 4.5 µm (pt = 10.3).

Claws of the Isohypsibius type ( Fig. 5D –G), slightly different in shape and size on each leg, large and stout, with poorly developed accessory points on the main branches; external claws with wide basal portion enlarged at the very base, internal with smaller basal portion; smooth lunules present, well developed under both the internal and external claws of the first three pairs of legs ( Fig. 5 F, arrow). A cuticular bar partially divided into dots was present beside the base of the internal claws of the first three pairs of legs ( Fig. 5 G, arrow). The measurements of the claws and the other metric characters of the holotype are reported in Table 4 .

Remarks. The paratypes showed the same, both qualitative and metric, characters of the holotype. The measurements of some structures are reported in Table 4 . Smooth eggs (4–7) laid into the exuvium.

Etymology. The name of the species refers to the stout claws: “ solidus ” = “stout”, “ unguis ” = “claw”.

Type depositories. The type material is deposited in the Binda and Pilato collection (Museum of the Department of Animal Biology “Marcello La Greca”, University of Catania).

Differential diagnosis. Doryphoribius solidunguis sp. nov. differed from D. flavus by having cuticular sculpture with smaller mesh ( Table 5); the reticular design appeared more irregular due to the more variable width of the ridges, which were also more protruding and formed tubercles at some crossings. The legs had no reticular ornamentation. The new species had only two pairs of dorso-lateral teeth in the buccal cavity; stouter claws ( Figs. 1 C– D, 2E and 5D–G); more evident lunules of the inner claws ( Figs. 2 F and 5F); and a cuticular bar on the first three pairs of legs.

D. solidunguis sp. nov. differed from D. polynettae above all in lacking cuticular sculpture on the ventral surface; by having a far more obvious dorsal cuticular sculpture with some tubercles present at the crossing of the mesh; pores nor roughness on the cuticle, absent; swollen portions of the legs; only two pairs of teeth in the oral cavity; wider buccal tube, stouter claws; and cuticular bars on the legs.

Doryphoribius solidunguis sp. nov. differed from D. amazzonicus sp. nov. by having the reticulate cuticular sculpture formed by thicker, more protruding ridges forming tubercles only at some crossing of the mesh. The largest mesh had higher pt index values ( Table 5). D. solidunguis sp. nov. also had slightly shorter buccal tube with respect to the body length ( Table 5); two pairs of teeth in the buccal cavity (not visible in D. amazzonicus ); stouter claws which were also longer with respect to the buccal tube length (compare Table 2 with Table 4 ). It had more evident lunules of the inner claws and a cuticular bar at the base of the inner claws on the first three pairs of legs, which is absent in D. amazzonicus .

D. solidunguis sp. nov. differed from D. bindae sp. nov. by having a more evident reticulate cuticular design with larger mesh ( Table 5) formed by far wider and more protruding ridges; tubercles present only at some crossing of the ridges; legs unsculptured; two pairs of teeth in the buccal cavity instead of only one; longer and stouter claws ( Table 5, and compare Table 3 with Table 4 , Figs. 4D –F and 5D–G); more evident lunules of the inner claws, and a cuticular bar on the first three pairs of legs, absent in D. bindae sp. nov.

D. solidunguis sp. nov. differed from D. quadrituberculatus above all by lacking dorsal gibbosities; mesh comprising ridges with tubercles at some of the crossings; swollen portions of the legs; peribuccal papulae; only two pair of dorsal teeth in the oral cavity; lunules at the base of the claws; and cuticular bars on the legs.

D. solidunguis sp. nov. differed from D. smokiensis by having eyes; different type of cuticular sculpture; swollen portions of the legs; only two pairs of dorsal teeth in the oral cavity; far narrower buccal tube; lunules at the claw base; cuticular bars on the legs; and other minor details.

mer paratype of Doryphoribius citrinus ; the values in brackets are from another paratype of the same body size), the paratype

of Doryphoribius amazzonicus sp. nov., the holotype of D. bindae sp. nov. and a paratype of D. solidunguis sp. nov.; “Styl.

supp. insert.” indicates the stylet supports insertion point on the buccal tube; “% bo-le” indicates the percentage ratio with

respect to the body length (calculated for the buccal tube length, the placoid row, the claws and the largest mesh).

D. flavus D. amazzonicus sp. nov. D. bindae sp. nov. D. solidunguis sp. nov. slide N. 1200 slide N. 4828 slide N. 3609 slide N. 3796

Characters µm pt % bo-le µm pt % bo-le µm pt % bo-le µm pt % bo-le

Body length 404 - - 241.2 - - 327.6 - - 361.3 - -

Buccal tube length 46.7 - 11.6 33.2 13.8 - 36.7 - 11.2 41.2 - 11.4

Figures

FIGURE 5. D. solidunguis sp. nov. A, Cuticular sculpture of the caudal portion of a paratype; B, Bucco-pharyngeal apparatus of the holotype; C, Anterior portion of the buccal tube showing the teeth of the buccal cavity (arrow); D, Claws of the second pair of legs of the holotype; E, Claws of the fourth pair of legs of the holotype; F, Lunule of the inner claw (arrow) of the second pair of legs of the holotype (the lunule of the external claw is not in focus); G, Cuticular bar (arrow) beside the internal claw of the third pair of legs of the holotype. Scale bar = 10 µm.

FIGURE 1. D. flavus. A, Dorso-lateral teeth (arrows) of the buccal cavity of a paratype; B, Bucco-pharyngeal apparatus of another paratype; C, Claws of the second and third pairs of legs of the same paratype as Fig. 1 B; D, claws of the fourth pair of legs of the same paratype as Fig. 1 B – C. Scale bar = 10 µm.

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.

FIGURE 4. D. bindae sp. nov. A, Cuticular sculpture of the caudal portion of a paratype; B, Caudal portion of the holotype: some tubercles are in focus (arrows); C, Leg of the second pair of a paratype, also sculptured on the swollen portion (arrow); D, Bucco-pharyngeal apparatus and first pair of legs of the holotype; E, Dorsal teeth of the buccal cavity (arrows) of a paratype; F, Claws of the fourth pair of legs of the holotype. Scale bar = 10 µm.

Tables

TABLE 4. Measurements of selected morphological structures of the holotype and the smallest and largest paratype of Doryphoribius. solidunguis sp. nov.; “ Styl. supp. insert. ” indicates the stylet supports insertion point on the buccal tube; “ % bo-le ” indicates the percentage ratio with respect to the body length (calculated for the buccal tube length, the placoid row, the claws and the largest mesh).

Body length	>325.8 - (contracted)	-	>193.5 - (contracted)	-	361.3	-	-
Buccal tube length	43.6 -	?	28.7 -	?	41.2	-	11.4
Buccal tube width	5.9 13.5	-	3.5 12.2	-	5.9	14.3	-
Styl. supp. insert.	- 70.0	-	- 72.3	-	-	71.8	-
Ventral lamina	25.4 58.3	-	18.1 63.1	-	25.4	61.6	-
Placoid row	15.2 34.9	?	7.8 27.2	?	14.0	34.0	3.9
I macroplacoid	8.5 19.5	-	4.7 16.4	-	8.2	19.9	-
II macroplacoid	4.5 10.3	-	2.8 9.8	-	5.0	12.1	-
I ex. claws	24.0 55.0	?	??	?	?	?	?
I int. claws	??	?	10.9 38.0	?	?	?	?
II ex. claws	??	?	??	?	?	?	?
II int. claws	??	?	??	?	?	?	?