Calcarobiotus (Calcarobiotus) parvicalcar, Pilato, Giovanni & Lisi, Oscar, 2009

Pilato, Giovanni & Lisi, Oscar, 2009, Description of three new species of Tardigrada from the Seychelles, Zootaxa 2005, pp. 24-34 : 25-27

Calcarobiotus (Calcarobiotus) parvicalcar sp. n.

Fig. 1

Material examined: Mahé: La Misère: holotype and three paratypes from a moss sample collected (1994) by Dr. Pieralfio Verzì and Ms. Maria Scalia Verzì.

Type repository: The holotype (slide N. 3935) and paratypes are deposited in the collection of Binda & Pilato (Museo del Dipartimento di Biologia Animale “Marcello La Greca”, Università di Catania).

Species diagnosis: Cuticle smooth, eye spots absent; buccal armature with ten peribuccal lamellae, an anterior and a posterior band of teeth difficult to see and a system of three dorsal and three ventral transverse ridges; stylet supports inserted on the buccal tube at 78–80 % of its length; three macroplacoids and a large microplacoid present; claws of Calcarobiotus type with very small basal spurs (almost invisible in some orientations).

Description of the holotype: Body length about 250 μm; colorless; eye spots absent; cuticle smooth. Bucco-pharygeal apparatus of Macrobiotus type ( Fig. 1 A). Terminal mouth with ten peribuccal lamellae; buccal cavity wall with an anterior band of very small teeth difficult to see, a posterior band of teeth and a system of three transverse dorsal and three ventral ridges (in some paratypes the medioventral ridge is subdivided into two or more teeth). Buccal tube rigid, 30.5 μm long and 5.4 μm wide externally (pt = 17.7). Stylet supports inserted on the buccal tube with a pt index of 79.8. Pharyngeal bulb (23.1 μm x 17.2 μm) with apophyses, three macroplacoids and a large microplacoid. The first macroplacoid 4.8 μm long (pt = 15.7), the second 3.5 μm (pt = 11.5), the third, with a pre-terminal narrowing, 4.1 μm long (pt = 13.4); microplacoid 3.6 μm long (pt = 11.8); entire placoid row 16.9 μm long (pt = 55.4), macroplacoid row 12.9 μm long (pt = 42.3).

Claws of Calcarobiotus type on all legs ( Fig. 1 B–D); the wide basal portion has a spur on each side; main and secondary branches of similar length and diverging almost from their origin. The basal spurs are very small on all legs; on the fourth pair of legs ( Fig. 1 D) the spurs are visible only with a favourable orientation of the claws; in some orientations they become impossible to see. On second and third pair of legs, external and internal claws 6.2 μm long (pt = 20.3) and 6.5 μm long (pt = 21.3); on fourth pair of legs the external and the internal claws are 6.6 μm long (pt = 21.6) and 7.3 μm long (pt = 23.9) respectively. All main branches have accessory points; smooth lunules present with thickened margin; a noticeable cuticular thickening is present below the lunules on the first three pairs of legs. Eggs unknown.

Etymology: The name parvicalcar refers to the small dimensions of the basal spur of the claws (parvus = small; calcar = spur).

Remarks: Calcarobiotus (C.) parvicalcar sp. n. has smaller basal spurs on the claws than any of the other species within the subgenus, i.e., Calcarobiotus (C.) gildae ( Maucci & Durante Pasa, 1980) , C. (C.) filmeri Dastych 1993 , C. (C.); occultus Dastych, 1993 and C. (C.) imperialis Abe & Takeda 2000 . Its lack of eyes also distinguishes it from C. (C.) filmeri and C. (C.) gildae , a longer microplacoid from C. (C.) occultus , and smaller claws, which have smooth lunules and a small basal spur on both sides of all the claws, from C. (C.)

gildae . The slightly larger first and second macroplacoids and shorter claws differentiates the new species from C. (C.) imperialis (see Table 1 ).

The four specimens here attributed to the new species Calcarobiotus parvicalcar in a paper of 1995 Binda & Pilato erroneously attributed to Macrobiotus diffusus .

* Values from Abe & Takeda, 2000.

Figures

FIGURE 1. Calcarobiotus parvicalcar sp. n. A, bucco-pharyngeal apparatus of the holotype. B, claws of the second and third pairs of legs of the holotype; arrows indicate the cuticular bar near the lunules. C, claws of the second pair of legs of the holotype; arrows indicate a basal spur. D, claws of the fourth pair of legs of the holotype; arrow indicates a basal spur. (Scale bar = 10 µm).

Tables

TABLE 1. Measurements (in μm), and values of the pt index, of some structures of the smallest and the largest measured specimens of Calcarobiotus (C.) parvicalcar sp. n. and of a specimen of Calcarobiotus (C.) imperialis of a comparable body length.

	C. (C.) parvicalcar sp. n. smallest specimen	C. (C.) imperialis * largest specimen (holotype)
Body length	about 230	about 250 258
Buccal tube length Buccal tube external width	28.3 4.9	30.5 32.2 5.4 4.7
pt	17.3	17.7 14.1
Stylet supports pt Placoid row	78.2 15.7	79.8 78.4 16.9?
pt	55.5	55.4?
Macroplacoid row pt	12.3 43.5	12.9? 42.3?
First macroplacoid	4.4	4.8 3.9
pt Second macroplacoid	15.6 3.4	15.7 11.8 3.5 3.0
pt	12.0	11.5 8.9
Third macroplacoid pt	4.0 14.1	4.1 4.1 13.4 12.2
Microplacoid	3.3	3.6 3.9
pt Internal claws II,III	11.7 6.1	11.8 11.8 6.2 8.6
pt	21.6	20.3 25.9
External claws II, III pt	6.7 23.7	6.5 10.9 21.3 32.9
Anterior claws IV	6.9	6.6 10.1
pt Posterior claws IV	24.4 7.4	21.6 30.6 7.3 11.3
pt	26.2	23.9 34.1