Bryodelphax brevidentatus, Kaczmarek, Łukasz, Michalczyk, Łukasz & Degma, Peter, 2005

Kaczmarek, Łukasz, Michalczyk, Łukasz & Degma, Peter, 2005, A new species of Tardigrada Bryodelphax brevidentatus sp. nov. (Heterotardigrada: Echiniscidae) from China (Asia), Zootaxa 1080, pp. 33-38 : 34-38

Bryodelphax brevidentatus sp. nov. ( Figs. 1 , 3–4 , 7–9 )

Type material. Holotype and 40 paratypes: Asia, China, Sichuan Province, Kangding Nature Reserve, 2650 m asl, August 2002, moss sample from rocks, Ms K. Ratyńska.

Type depositories. Holotype and 10 paratypes (1 slide) are deposited in the Natural History Collections, Faculty of Biology, A. Mickiewicz University, Umultowska 89, 61­ 614 Poznań, Poland, 14 paratypes (2 slides) are deposited in the Department of Animal Taxonomy and Ecology, A. Mickiewicz University, Poznań, 8 paratypes (1 slide) are deposited in the Department of Zoology, Faculty of Natural Sciences, Comenius University, Slovakia, 8 paratypes (1 slide) are deposited in the Department of Biology, McMurry University, Abilene, Texas, U.S.A.

Description. Holotype (female): Total body length without hind legs 136.0 ( Fig. 1 ). Body coloured light orange, eyes absent or not visible after preparation. Apart from head appendages, only lateral appendages cirri A present. Internal cirri 5.0 long, cephalic papilla 3.0 long, external cirri 12.0 long. Appendages cirrus A 28.0 long (20.6% of body length). Clava oval.

Ventral plates absent. Dorsal plates covered with dense and regular granulation (about 0.5–0.7 in diameter), distinctly larger on scapular and terminal plates (about 0.7–1.0 in diameter). In addition to granulation, slightly larger irregularly distributed pores are visible on entire plates but more densely distributed on margin of plates (about 1.0 in diameter). Scapular plate divided into two parts by median, longitudinal and thin stripe. Paired plates divided into two unequal anterior and posterior parts by transverse and very thin stripe without granulation. Paired plates 2 with crenulated posterior margin. Median plates 1 and 2 divided into two unequal parts ( Fig. 1 ). Median plate 3 undivided and triangular in shape. Granules on median plates distinctly smaller then those on other plates (about 0.3 in diameter). Terminal plate with two longitudinal and thin stripes which divide the plate into three parts.

Spine on the first pair of legs and papilla on fourth pair present. Dentate collar on fourth pair of legs with 5 small, triangular teeth arranged irregularly ( Figs. 3–4 , 7–9 ).

Claws of fourth pair of legs 7.0 long. External claws of all legs smooth, internal claws with very small spur 1.0 long near their base (oriented downwards).

Remarks. Measurements of 16 randomly selected specimens (females) (holotype and paratypes) are given in Table 1 . The paratypes are similar to the holotype and differs from them mainly by different number of collar teeth and size of some characters ( Tab. 1 ). Etymology. The name brevidentatus refers to the general appearance of dentate collar in the new species, brevis = short, dentatus = toothed.

Differential Diagnosis. Bryodelphax brevidentatus sp. nov. is most similar to B. tatrensis ( Figs. 2 , 5–6 , 10–12 ) by the presence of similar dorsal sculpture and by the presence of a dentate collar on the fourth pair of legs. The new species differs from B. tatrensis by much smaller and differently shaped teeth on the dentate collar (wide and short in B. brevidentatus and slender, sharp and long in B. tatrensis ); relatively smaller claws, similar in length on all legs (in B. tatrensis , claws on IV pair of legs are distinctly longer than others).

In addition, the new species differs from:

1. Bryodelphax alzirae by different colour of the body (brick red in B. alzirae and light orange in B. brevidentatus sp. nov.), presence of pores in the cuticle (only irregular granulation in B. alzirae ), absence of small supplementary plates (three pairs of such plates in B. alzirae ), much smaller number of teeth in dentate collar (12 teeth in B. alzirae and 47 in B. brevidentatus sp. nov.).

2. B. mateusi by different colour of the body (colourless or yellowish in B. mateusi ) and by absence of small supplementary plates (six pairs of such plates in B. mateusi ).

3. B. amphoterus by different colour of the body (colourless or very slightly rose in B. amphoterus ) and different sculpture (more evident granulation with slightly stellate shape in B. amphoterus ), shorter cirri A (about 40.0–50.0 in B. amphoterus and less than 30.0 in B. brevidentatus sp. nov.), generally smaller number of teeth in dentate collar and lacking of spur on external claws, terminal plates divided in three parts by unsculptured stripes (not marked in the description and drawing of B. amphoterus ).

We are grateful to Ms Katarzyna Ratyńska who collected material for us, Professor Barbara Wçglarska for the loan of the type material of B. tatrensis and Dr. Wojciech Magowski for making a phase contrast microscope available to us.

Figures

FIGURES 1 – 2. 1, Bryodelphax brevidentatus sp. nov., habitus (PCM); 2, Bryodelphax tatrensis W glarska, habitus of type specimen (PCM).

FIGURES 3 – 6. Dentate collars: 34, Bryodelphax brevidentatus sp. nov. (PCM); 56, Bryodelphax tatrensis Wçglarska (PCM).

FIGURES 7 – 12. Dentate collars: 79, Bryodelphax brevidentatus sp. nov.; 1012, Bryodelphax tatrensis Wçglarska (not scaled).

Tables

TABLE 1. Measurements [in µm] of selected morphological structures of 16 specimens of Bryodelphax brevidentatus sp. nov. mounted in Hoyers medium (MIN and MAX refer to the smallest and the largest structure found among all measured specimens).

CHARACTER	N	MIN MAX	MEAN	SE
Body length	16	117.0 165.0	149.4	3.38
Cirrus A length	16	21.0 28.5	25.2	0.53
Internal Cirrus length	15	4.5 6.0	5.1	0.09
Cephalic papilla length	11	3.0 5.0	4.0	0.12
External Cirrus length	16	7.0 12.0	10.3	0.33
Length of teeth in dentate collar	15	1.0 2.0	1.4	0.10
Claws on IV pair of legs length	14	5.5 8.0	7.2	0.21
Number of teeth in dentate collar	15	4 7	4.9	0.26