Diphascon (Diphascon) zaniewi, Kaczmarek, L Ukasz & Michalczyk, L Ukasz, 2004

Kaczmarek, L Ukasz & Michalczyk, L Ukasz, 2004, Notes on some tardigrades from South Africa, with the description of Diphascon (Diphascon) zaniewi sp. nov. (Eutardigrada: Hypsibiidae), Zootaxa 576, pp. 1-6 : 2-5

1. Diphascon (Diphascon) zaniewi sp. nov.

( Figs 1–4 ; Tab. 1 )

Description

Holotype (2272/1): Body length 184.3 ( Fig. 1 ). Body slender, transparent, eyes absent. Cuticle on dorsal and ventral side smooth and without pores. Peribucal lamellae and papulae absent.

Bucco­pharyngeal apparatus without strengthening bar. Drop­shaped structure between rigid buccal and flexible pharyngeal tube present. Bucco­pharyngeal tube 53.2 long. Buccal tube 18.5 long and 0.9 [4.9] wide (34.8 % of total length of bucco­pharyngeal tube). Pharyngeal tube 34.7 long and 0.9 [4.9] wide. At end of pharyngeal tube small triangular apophyses present. Stylet supports inserted on buccal tube at 10.9 [58.9]. Pharyngeal bulb oval with three rod­shaped macroplacoids (without central constrictions), very small granular microplacoid and septulum. First macroplacoid 2.9 [15.7] long, second 2.9 [15.7] long and third 4.3 [23.2] long. First and second macroplacoid in same length and each distinctly shorter then third one (configuration: 1­1­2). Septulum 1.9 [10.3] long. Macroplacoid row 11.4 [61.6] long. Placoid and septulum row 14.3 [77.3] long ( Fig. 2 ).

Claws well developed and with distinct accessory points on primary branches. Claws on III pair of legs: external 8.6 [46.5], internal 6.2 [33.5]; IV pair of legs: posterior 9.5 [51.4], anterior 6.7 [36.2]. Lunules and other cuticular structures on legs absent ( Figs 3–4 ). Eggs unknown.

Type material

Holotype (2272/1) and 7 (3 in simplex stage) paratypes on two slides (2272/1 and 2272/3): South Africa, Sun City, Dragon Mountains, moss from soil, 1000 m asl, near the waterfall, 12.2003, leg. Krzysztof Kaczmarek.

Type depositories

Holotype (2272/1) and 3 paratypes (2272/1) (one in simplex stage) are preserved at the Department of Animal Taxonomy and Ecology, A. Mickiewicz University, Pozna–, 3 paratypes (2272/3) (2 in simplex stage) are preserved in the collection of £. MICHALCZYK (Jagiellonian University, Poland).

Differential diagnosis

Diphascon (Diphascon) zaniewi sp. nov. differs from all species of the pingue group by having a very narrow buccal tube (less then 1.0) and second macroplacoid in the same length as the first one. Besides, it differs from the most similar:

1. Diphascon . (D.) pingue Marcus, 1936 by: smaller percentage proportion of buccal tube to bucco­pharyngeal tube (37.8–39.8 in D. (D.) pingue and 34.8–35.9 in D. (D.) zaniewi sp. nov.); longer macroplacoid row (6.7–10.7 [53.5–58.8] in D. (D.) pingue and 11.4–11.9 [61.6–65.7] in D. (D.) zaniewi sp. nov.); longer placoid and septulum row(8.7– 13.9 [51.5–62.9] in D. (D.) pingue and 14.3 [77.3–79.0] in D. (D.) zaniewi sp. nov.).

2. Diphascon (D.) pinguiforme Pilato & Binda, 1997 /98 by: smaller percentage proportion of buccal tube to bucco­pharyngeal tube (37.04 in D. (D.) pinguiforme and 34.8– 35.9 in D. (D.) zaniewi sp. nov.); shorter macroplacoids 1 and 2 (I­ 3.4–3.6 [18.7–19.0]; II­ 3.1–3.6 [16.9–19.0]) in D. (D.) pinguiforme and (I­ 2.9 [15.7–16.0]; II– 2.9 [15.7–16.0]) in D. (D.) zaniewi sp. nov.); shorter septulum (2.2–2.5 [11.8 –13.8] in D. (D.) pinguiforme and 1.9 [10.3–10.5] in D. (D.) zaniewi sp. nov.).

Figures

FIGURES 1 – 4. Diphascon zaniewi sp. nov. 1 — Habitus; 2 — Bucco­pharyngeal apparatus; 3 — Claws of the second pair of legs; 4 — Claws of the fourth pair of legs.

Tables

TABLE 1. Measurements [in µm] and the ptd values of selected morphological structures of specimens of Diphascon (D.) zaniewi sp. nov. mounted in Hoyer’s medium (in the body length order).

CHARACTERS	Paratype 1 [µm] ptd	Paratype 2 [µm] ptd	HOLOTYPE [µm] ptd
Body length	175.8 950.3	183.4 1013.3	184.3 996.2
Buccal tube length	18.5 ­	18.1 ­	18.5 ­
Bucco­pharyngeal tube length	52.3 282.7	50.4 278.5	53.2 287.6
Level of the stylet support insertion point	10.9 58.9	10.5 58.0	10.9 58.9
Buccal tube external width	0.9 4.9	0.9 5.0	0.9 4.9
Macroplacoid 1 length	2.9 15.7	2.9 16.0	2.9 15.7
Macroplacoid 2 length	2.9 15.7	2.9 16.0	2.9 15.7
Macroplacoid 3 length	4.8 25.9	3.8 21.0	4.3 23.2
Septula length	1.9 10.3	1.9 10.5	1.9 10.3
Macroplacoid row length	11.4 61.6	11.9 65.7	11.4 61.6
Placoid row length	14.3 77.3	14.3 79.0	14.3 77.3
Primary branch of external claw 2 length	8.6 46.5	8.6 47.5	8.6 46.5
Primary branch of internal claw 2 length	5.7 30.8	5.7 31.5	6.2 33.5
Primary branch of external claw 4 length	5.7 30.8	6.2 34.3	6.7 36.2
Primary branch of internal claw 4 length	8.6 46.5	9.0 49.7	9.5 51.4