Ramazzottius bunikowskae, Kaczmarek, Łukasz, Michalczyk, Łukasz & Diduszko, Dawid, 2006

Kaczmarek, Łukasz, Michalczyk, Łukasz & Diduszko, Dawid, 2006, Ramazzottius bunikowskae, a new species of Tardigrada (Eutardigrada, Hypsibiidae) from Russia, Zootaxa 1229, pp. 49-57 : 50-56

Ramazzottius bunikowskae sp. nov.

( Figs. 1–17 )

Description

Adult (measurements of holotype): Body length 222.0 ( Figs. 1–3 ). Body red due to pigmented transverse bands on dorsal side. Dorsal cuticle with well visible, polygonal tubercles (1.0–3.0 in diameter) clearly larger in posterior part of the body ( Figs. 4–5 ). Tubercles arranged in 8 transverse bands. Granulation on legs absent except for a stripe with small tubercles present on the external parts of legs IV.

Eyes absent. Head with two elliptical organs on posterior dorso­lateral sides of head ( Figs. 6–7, 8 , arrow a). Elliptical organs with some pores (visible in SEM only, Fig. 6 ). On anterior dorso­lateral sides of head two strongly porous areas which could be external parts of chemoreceptors (visible in SEM only) ( Figs. 6 , 9 ). Mouth opening antero­ventral, surrounded by six somewhat indistinct peribuccal lobes and also six small and sometimes undeveloped peribuccal papillae, placed in between lobes (visible in SEM only) ( Fig. 10 ).

Bucco­pharyngeal apparatus of Ramazzottius ­ type ( Fig. 13 ) with apophyses for insertion of the stylet muscles blunt­hook shaped, asymmetrical in size and shape, with respect to the frontal plane. Oral cavity armature poorly developed and hardly visible in PCM. Only one band of very small, conical teeth, arranged in 3–5 rows present. Teeth located on ring fold, in posterior oral cavity. Buccal tube 29.5 long ( Fig. 13 ). Buccal tube width: internal 1.0 [3.4], external 2.0 [7.0] with one bend in posterior part of tube (visible only in lateral view). Stylet supports inserted on buccal tube at 16.5 [56.0]. Pharyngeal bulb slightly oval with apophyses and two macroplacoids ( Fig. 13 ). Microplacoid and septula absent. Pharyngeal apophyses very large (almost as large as macroplacoids) and triangular in shape. Macroplacoids slightly oval, without constrictions. First macroplacoid 3.0 [10.2] long. Second macroplacoid shorter, 2.0 [7.0] long. Macroplacoid row 6.0 [20.3] long.

Claws of Ramazzottius ­ type, ( Figs. 11–12 , 14–15 ). Primary branches of external claws long and thin, not connected with secondary branches ( Figs. 11–12 ). Poorly visible lunules on all legs present, better developed on IV pair of legs. Accessory points on primary branches of all external and internal claws present. External (ext) claw of I pair of legs 14.0 [47.0] long, base (bs) of the claw 5.0 [16.9]; II ext ( Fig. 11 ). 16.0 [54.2], bs 6.0 [20.3]; III ext. 16.0 [54.2], bs 6.0 [20.3]; IV ext. 19.0 [64.4], bs 6.0 [20.3], internal 9.0 [30.5]. Bars and other cuticular thickenings on legs absent.

Egg: White/colourless, large laid freely ( Figs. 16–17 ). Spherical, with conical processes with very small enlarged, bulbous base. Egg processes situated very close to each other (sometimes in contact). Some processes with bifurcated tips ( Fig. 17 ). Egg processes and surface between processes probably smooth (in LM). Diameter of egg without processes 85.0 and 104.0 including them. Processes 11.0–17.0 high with basal diameter 5.0–7.0.

Remarks

Results of simple statistical analysis of measurements and pt values of selected morphological structures for eight specimens are given in Table 1 . The peribuccal lobes, papillae and porous areas on the head have never been reported in the genus Ramazzottius before, therefore it is not known if these structures are also present in other species of the genus. Processes on eggs seems to be surrounded by rings of small granules but this character should be confirmed based on larger number of eggs because it could be only an artifact.

Material examined

Twelve specimens and one egg, Russia, Irkutsk Province, northern part of Olhon Island on Lake Baikal, taiga, lichen from stone, near the coast, 05.08.2004; leg. D. Diduszko.

Type depositories. Holotype and 8 paratypes (7 adults and 1 egg) are deposited in the Natural History Collections, Faculty of Biology, A. Mickiewicz University, Umultowska

89, 61–614 oznań, Poland.

Etymology

The first author takes great pleasure in dedicating the new species to a beautiful, incredible and close to him woman, Anna Bunikowska.

Differential diagnosis

Ramazzottius bunikowskae sp. nov. is similar to R. caucasicus Biserov, 1998 and R. tribulosus Bertolani & Rebecchi, 1988 in regard to the shape of egg processes. The new species differs from R. caucasicus by:

1. the presence of sculpture on the dorsal side of the body and by very densely arranged egg processes (in R. caucasicus the processes are more spaced).

2. shorter external claws (19.0–32.0 in R. caucasicus and 18.0–20.0 in the new species).

3. different colour of the body (brown in R. caucasicus and red in the new species).

4. larger egg diameter (without processes): 55.0–63.0 in R. caucasicus and 85.0 in the new species.

Ramazzottius bunikowskae sp. nov. differs from R. tribulosus by:

1. longer (7.7–9.6 in R. tribulosus and 11.0–17.0 in the new species) and wider base of the egg processes (3.9–4.2 in R. tribulosus and 5.0.0–7.0 in the new species).

2. very densely arranged egg processes (in R. tribulosus the processes are more spaced).

3. bulbous base and conical apices of egg processes (processes conical without bulbous base in R. tribulosus ).

4. larger egg diameter (without processes): 53.8–59.0 in R. tribulosus and 85.0 in the new species.

5. shorter claws:

a) leg I external/internal (18.5/ 11.1 in R. tribulosus (specimen 287.1 long) and 14.5/9.0 in the new species (specimen 285.0 long));

b) leg II internal (11.4 in R. tribulosus (specimen 287.1 long) and 9.0 in the new species (specimen 285.0 long));

c) leg IV external/internal (22.8/ 12.9 in R. tribulosus (specimen 287.1 long) and 20/ 10.0 in the new species (specimen 285.0 long)).

Figures

FIGURES 1 – 2. Ramazzottius bunikowskae sp. nov. Habitus. 1, lateral view; 2, dorsal view. (SEM)

FIGURES 3 – 4. Ramazzottius bunikowskae sp. nov. 3, habitus (ventro­lateral view); 4, caudo – dorsal cuticle. (PCM)

FIGURES 5 – 8. Ramazzottius bunikowskae sp. nov. 5, caudo­dorsal cuticle; 6, head (lateral view, frame shows the fragment blown up on Fig. 9); 7, head (dorsal view, frame shows the fragment blown on Fig. 8); 8, elliptical organ (the right one from Fig. 7, a: elliptical organ, b and c: cribriform areas). (SEM)

FIGURES 9 – 12. Ramazzottius bunikowskae sp. nov. 9, fragment of head cuticle from Fig. 6, arrow indicates a cribriform area (external evidence of muscle attachment), arrowhead indicates a porous area that could be an external part of a chemoreceptor; 10, mouth opening, arrow indicates one of six peribuccal papillae; 11, claws II; 12, a closer look at the external claw from Fig. 11 showing that the basal claw and the primary branch are not connected. (SEM)

FIGURES 13 – 15. Ramazzottius bunikowskae sp. nov. 13, buccal apparatus; 14, claws II; 15, claws IV. (PCM, scale on 14 – 15 same as on 13)

FIGURES 16 – 17. Ramazzottius bunikowskae sp. nov. The egg. 16, whole egg; 17, processes and surface). (PCM)

Tables

TABLE 1. Measurements [in µm] and pt values of selected morphological structures of specimens of Ramazzottius bunikowskae sp. nov. mounted in Hoyer’s medium (RANGE refers to the smallest and the largest structure found among all measured specimens; N: number of specimens / structures measured, SD: standard deviation).

CHARACTER	N	RANGE	MEAN	SD
		µm pt	µm pt	µm pt
Body	8	222.0– 357.0 752.5– 1084.7	298.0 941.0	40.9 100.4
Buccaltube	8	29.5– 37.5 ­	31.7 ­	3.2 ­
Stylet support insertion point	8	16.5– 21.0 53.2– 57.6	17.6 55.6	1.8 1.2
Buccal tube internal width	8	1.0– 1.0 2.7– 3.4	1.0 3.2	0.0 0.3
Buccal tube external width	8	2.0– 3.0 6.8– 8.1	2.3 7.3	0.4 0.6
Macroplacoid 1	8	2.5– 4.0 8.3– 10.7	3.1 9.7	0.4 0.8
Macroplacoid 2	8	2.0– 3.0 5.6– 8.0	2.1 6.7	0.4 0.7
Placoid row	8	6.0– 8.0 19.4– 23.7	6.8 21.3	0.7 1.5
Claw 1 ­ external	6	14.0– 21.0 47.5– 67.7	16.6 53.1	3.4 7.8
Claw 1 ­ external base	6	4.0– 7.0 13.6– 22.6	5.6 17.9	1.2 3.0
Claw 1 ­ internal	7	7.0– 10.0 23.7– 32.3	8.9 27.8	1.1 3.2
Claw 1 ­ internal base	7	5.0– 12.0 16.9– 32.0	7.9 24.2	2.5 5.8
Claw 2 ­ external	6	15.0– 22.0 50.8– 58.7	16.7 53.4	2.7 3.0
Claw 2 ­ external base	6	5.0– 7.0 16.9– 20.3	5.8 18.8	0.8 1.5
Claw 2 ­ internal	6	8.5– 11.0 24.0– 35.5	9.6 30.0	1.1 3.7
Claw 2 ­ internal base	6	6.5– 12.0 22.0– 32.3	8.6 26.5	2.2 4.5
Claw 3 ­ external	6	16.0– 19.0 54.2– 61.3	17.3 57.5	1.1 2.4
Claw 3 ­ external base	6	6.0– 9.0 20.3– 29.0	6.8 22.7	1.2 3.4
Claw 3 ­ internal	6	9.0– 12.0 27.8– 35.5	10.0 31.1	1.3 2.5
Claw 3 ­ internal base	6	7.0– 9.0 22.2– 29.0	8.0 25.0	0.9 2.6
Claw 4 ­ external	7	18.0– 20.0 55.6– 67.8	19.3 62.7	1.0 3.9
Claw 4 ­ external base	7	6.0– 8.0 20.3– 25.8	6.7 21.7	1.0 2.1
Claw 4 ­ internal	8	9.0– 12.0 27.8– 35.5	10.3 32.4	1.0 2.7
Claw 4 ­ internal base	8	7.0– 9.0 23.7– 30.5	8.5 26.9	0.8 2.5