Echiniscus ollantaytamboensis Nickel, Miller & Marley, 2001

Michalczyk, Łukasz & Kaczmarek, Łukasz, 2006, Revision of the Echiniscus bigranulatus group with a description of a new species Echiniscus madonnae (Tardigrada: Heterotardigrada: Echiniscidae) from South America, Zootaxa 1154, pp. 1-26 : 13-19

Echiniscus ollantaytamboensis Nickel, Miller & Marley, 2001 ( Figs. 43–68 , 73 )

Material examined

Two paratypes (1 adult and 1 juvenile), from Ollantaytambo, Peru, South America; 42 Description

Adult female (measurements of a female from Puno, Peru): body length 375.3 ( Figs. 43–46 ). Body red. Red eyes visible in living specimens only. Internal cirrus 14.3 long, external cirrus 41.8 long; internal/external cirrus ratio = 0.34. Cephalic papilla 9.5 long. Apart from head cirri and cirrus A no other appendices present. Cirrus A 87.4 long, ending in a point. Cirrus A/body ratio = 0.23. Clava 9.5 long.

Dorsal (plate) cuticle with true pores, pseudopores (hollows) and with true granulation ( Figs. 47–52 ). Granules (true granulation, on cuticle surface) present between scapular and first paired plate (small granules, ca. 0.3–0.5 in diameter), on stripes in anterior portions of paired plates, in anterior part of second median plate, and between third median plate and terminal plate (larger granules, ca. 0.5–1.5 in diameter). Granules often connected by strips of cuticle, so spaces between granules and stripes form shallow pseudopores (hollows) ( Figs. 51 , 57 ). Granulated areas change smoothly into areas with pores and pillars ( Figs. 51 , 60 ). Cuticle appearance in SEM: pores large (1.0–2.0 in diameter) ( Figs.51–52 ). ‘Sponge layer’ narrow, large pillars present ( Figs. 53–54 , 73 ). Cuticle visible in PCM: Pores and pseudopores visible as bright, fields; when focusing down through cuticle, cuticular pillars appear as dark dots ( Figs. 47–50 ). Pores, pseudopores and cuticular pillars very well focusable. Ventral cuticle with very fine, dense and regular granulation.

All plates well developed. Head and scapular plates not faceted. In LM lateral portions of scapular plate seem to be detached from the dorsal plate and form small shoulder plates (one on each side of the body) divided from the scapular plate by a thin bright stripe. This false division is caused by a bend of the plate where cuticle is thinner; in SEM this division is not visible. Third median plate present and developed anteriorly ( Figs. 59–60 ). Terminal plate faceted. Notches 23.8 long.

Spine on legs I in shape of short triangle, 4.8 long. Papilla on legs IV finger­like, 5.7 long ( Figs. 63–64 ). Dentate collar with fine granulation and faint pseudopores in LM (small, shallow pseudopores in SEM), and with 9 sharp, triangular teeth with wide bases ( Figs. 61–65 ).

Claws of legs IV 24.7 long. External claws of all legs without spurs, internal claws of all legs with a relatively small spur, curved downwards, growing out of claw at ca. 90o ( Figs. 66–68 ). Spur on claws of legs IV 2.9 long; spur/claw ratio = 0.12. Claws of legs I– III slightly shorter.

Remarks

Results of simple statistical analysis of measurements of selected morphological structures for 13 randomly chosen adult specimens are given in Table 4 , for all found juvenile specimens in Table 5 , and for all found larvae in Table 6 . One exuvium with three round eggs was found (eggs ca. 100.0 in diameter).

The anterior portion of the second median plate is granulated in smaller individuals ( Fig. 55 ) and in larger specimens apart from the granules there are also pseudopores present ( Figs. 56–57 ).

There are some discrepancies regarding the occurrence of the third median plate between the original description ( Nickel et al. 2001), photomicrographs in the original description and our observations on the type material and specimens found in Puno. The authors of the description state that the third median plate is absent, however it can be noted on the photomicrographs which they provided in the paper. From our observations we conclude that larvae and juvenile specimens do not have the third median plate, but the area between the second paired plates and the terminal plate is covered with granules ( Fig. 58 ). In adults the third median plate is present ( Figs. 59–60 ), however in smaller specimens it may be not fully developed and limited to the anterior portion.

The authors of the original description state also yellow colour of the body and that the body length varies between 180.0 and 275.0. In the population from Puno (including larvae) body length extremes are 147.3 and 467.4. and colour was more reddish. These differences are probably due to different environmental conditions in which two population have lived.

Type depositories

Holotype and 9 paratypes are preserved at the Academy of Natural Sciences, Philadelphia, PA, USA; 2 paratypes are preserved in the collection of Ł. Michalczyk.

Etymology

The species was named in honour of the ancient Inca ‘Temple of the Sun’, Ollantaytambo, Peru, near where it was found.

Differential diagnosis

For comparisons with other species of the bigranulatus group see Tables 7–8.

Figures

FIGURES 43 – 46. Echiniscus ollantaytamboensis — habitus (specimens from Puno, Peru); 43, dorso­lateral view (DIC), 44, dorso­lateral view (PCM), 45, lateral view (SEM), 46, dorsal view (SEM); 45 and 46 show the same specimen.

FIGURES 47 – 52. Echiniscus ollantaytamboensis — dorsal plate cuticle; 47, surface with pores (PCM), 48, pillars that appear when focusing down through the cuticle (PCM), 49, surface with pores (DIC), 50, pillars that appear when focusing down through the cuticle (DIC), 51, surface with pores, pseudopores and granules in the anterior part of one of the first paired plates (note strips of cuticle connecting granules and how granulated area with pseudopores smoothly becomes a plate with true pores), 52, surface with pores (SEM); 47 and 48 show the same fragment of cuticle, 49 and 50 show the same fragment of cuticle.

FIGURES 53 – 54. Echiniscus ollantaytamboensis — structure of dorsal plate cuticle (SEM) (see also Fig. 73).

FIGURES 55 – 60. Echiniscus ollantaytamboensis. 55, second median plate in a younger animal (DIC), 56 – 57, second median plate in an older animal (DIC and SEM, respectively), 58, weakly developed third median plate in a younger animal (DIC), 59 – 60, better developed third median plate in an older animal (DIC and SEM, respectively). Not scaled.

FIGURES 61 – 68. Echiniscus ollantaytamboensis. 61 – 64, dentate collar on the IV pair of legs (DIC) (61 and 62 come from the same specimen, 63 and 64 come from the same specimen), 65, dentate collar sculpture (SEM), 66 – 67, claws of the IV pair of legs (DIC and PCM, respectively), 68, claws of the III pair of legs (SEM).

FIGURES 72 – 74. Structure of dorsal plate cuticle in three species of the bigranulatus group (semischematic section based on SEM observations); 72, E. bigranulatus (see also Figs. 11 – 12), 73, E. ollantaytamboensis (see also Figs. 53 – 54), 74, E. madonnae sp. nov. (see also Figs. 31 – 32); abbreviations: bc — body cavity, cs — cuticle surface, pi — pillar, po — pore, pp — pseudopore, sl — ‘ sponge’ layer, up — undeveloped pillar. Not scaled.

Tables

TABLE 4. Lengths [in µm] and length ratios of selected morphological structures of adults of Echiniscus ollantaytamboensis mounted in Hoyer’s medium (MIN and MAX refer to the smallest and the largest structure found among all measured specimens; SD — Standard Deviation, N — number of specimens / structures measured). Specimens from population found in Peru.

CHARACTER MIN	MAX	MEAN	SD	N
Body 285.0	467.4	361.7	49.6	13
Internal cirrus 11.9	18.1	13.9	1.6	13
Cephalic papilla 8.6	14.3	10.7	1.8	12
External cirrus 30.4	46.6	38.0	5.0	13
Cirrus A 71.3	109.3	90.3	11.5	12
Clava 7.1	11.4	9.2	1.3	13
Spine on leg 1 3.8	5.7	5.0	0.7	12
Papilla on leg 4 4.8	7.1	5.8	0.9	11
Number of teeth on collar 5	11	8.0	1.8	13
Notch 19.0	28.5	24.8	2.8	13
Claw IV 20.0	28.5	24.2	3.1	10
Spur of claw IV 1.9	3.8	3.0	0.6	11
Spur/Claw ratio 0.11	0.15	0.13	0.02	9
Cirrus A /Body ratio 0.22	0.30	0.26	0.03	12
Cirrus int/ext ratio 0.32	0.44	0.37	0.03	13
Cirrus int/ A ratio 0.11	0.20	0.16	0.03	12
Cirrus ext/ A ratio 0.32	0.52	0.42	0.06	12