Milnesium granulatum Ramazzotti, 1962

Bartels, Paul J., Nelson, Diane R., Kaczmarek, Łukasz & Michalczyk, Łukasz, 2014, The genus Milnesium (Tardigrada: Eutardigrada: Milnesiidae) in the Great Smoky Mountains National Park (North Carolina and Tennessee, USA), with the description of Milnesium bohleberi sp. nov., Zootaxa 3826 (2), pp. 356-368 : 363-366

Milnesium granulatum Ramazzotti, 1962

( Figs 7–11 , Table 2 )

Material examined. Seven adult specimens: 35°39.2836'N, 83°26.1889'W, 1,978 m asl (Mt. LeConte, 06.11.2001); one adult specimens: 35°36.6820'N, 83°32.5381'W, 917 m asl (Goshen Prong, 10.06.2002); and one adult specimens: 35°41.1328'N, 83°29.8911'W, 594 m asl (Twin Creeks, 28.08.2002). All sites in the Great Smoky Mountains National Park, Tennessee, U.S.A., moss samples and lichen samples from trees; coll. P.J. Bartels.

Remarks. Milnesium granulatum was originally described from Chile by Ramazzotti (1962) as a variety of Milnesium tardigradum Doyère, 1840 but it was later elevated to the species level and placed in the granulatum group of species with sculptured cuticles by Michalczyk et al. (2012a,b). Our specimens correspond perfectly to the original description and the recent re-description (Michalczyk et al. 2012a,b). This is a new record for the USA and to North America (Meyer 2013). In the GSMNP tardigrade database, M. granulatum is extremely rare, occurring in only three of 19 sites, and making up only 0.06% of terrestrial tardigrades.

Figures

FIGURES 7 – 8. Milnesium granulatum. 7 — habitus; 8 — dorsal cuticle with polygonal reticulation. Scale bar units are micrometres.

FIGURES 9 – 11. Milnesium granulatum. 9 — buccal apparatus; 10 — claw III; 11 — claws IV. Scale on 11 same as in 10. Scale bars in micrometres.

Tables

TABLE 2. Measurements (in µm), pt values, and size normalised values (a * = intercept of log Y * vs. BTL) of selected morphological structures of six specimens of Milnesium granulatum mounted in Hoyer’s medium. Note that sample size for specific traits varied since not all traits were measureable on all individuals.? = trait oriented unsuitably for measurement.

CHARACTER	N	RANGE (µm)	RANGE (pt)	MEAN	SD	a*
		min – max	min – max	µm pt	µm pt	µm
Body length	6	244 – 535	875 – 1277	338 1056	109 152	327
Peribuccal papillae length	0	? –?	? –?	? ?	? ?	?
Lateral papillae length	0	? –?	? –?	? ?	? ?	?
Buccal tube
Length	6	19.1 – 49.5	–	32.5 –	10.9 –	–
Stylet support insertion point	5	13.6 – 32.6	63.8 – 71.4	22.3 67.4	7.3 3.7	21.8
Anterior width	6	9.6 – 27.0	50.3 – 57.4	17.5 53.8	6.0 2.4	17.7
Standard width	6	9.7 – 24.5	45.6 – 50.9	15.7 48.4	5.3 2.3	15.5
Posterior width	6	9.8 – 23.3	46.5 – 54.2	15.9 49.5	4.8 3.1	16.1
Standard width/length ratio	6	46% – 51%	–	50% –	2% –	48%
Posterior/anterior width ratio	6	86% – 102%	–	90% –	6% –	91%
Claw 1 lengths
External primary branch	4	10.3 – 12.0	25.0 – 58.3	11.3 41.7	0.8 13.6	11.5
External base + secondary branch	6	7.7 – 9.6	19.3 – 42.0	8.2 27.4	0.7 8.4	8.1
External spur	5	3.1 – 5.1	9.5 – 16.3	3.8 12.1	0.8 2.7	2.4
Internal primary branch	2	12.3 – 12.8	43.9 – 44.1	12.5 44.0	0.4 0.2	?
Internal base + secondary branch	5	7.4 – 11.2	19.9 – 28.6	8.6 25.1	1.5 3.8	5.2
Internal spur	3	3.0 – 5.7	10.6 – 13.5	4.2 11.8	1.4 1.5	1.0
Claw 2 lengths
External primary branch	4	10.8 – 14.6	29.5 – 56.8	12.0 41.4	1.8 11.5	9.8
External base + secondary branch	3	7.4 – 12.0	24.2 – 43.3	9.2 31.4	2.4 10.3	6.2
External spur	3	3.6 – 3.8	12.6 – 19.0	3.7 15.1	0.1 3.5	4.2
Internal primary branch	5	10.9 – 14.3	28.9 – 58.0	12.0 41.9	1.4 10.7	10.5
Internal base + secondary branch	4	7.2 – 10.7	21.6 – 40.6	8.6 29.4	1.5 8.1	6.5
Internal spur	1	3.6 – 3.6	18.8 – 18.85	3.6 18.8	??	?
Claw 3 lengths
External primary branch	5	9.5 – 17.0	23.0 – 56.7	12.6 40.7	2.9 12.7	10.5
External base + secondary branch	4	8.0 – 11.3	19.5 – 28.7	8.9 24.8	1.6 4.5	5.6
External spur	3	3.1 – 5.2	10.5 – 13.6	4.0 11.6	1.1 1.8	1.7
Internal primary branch	5	9.5 – 17.3	23.1 – 51.1	12.3 39.2	3.1 10.8	8.7
Internal base + secondary branch	4	8.0 – 9.1	18.4 – 31.2	8.6 24.5	0.6 6.5	9.2
Internal spur	3	3.5 – 4.7	9.5 – 13.1	4.0 11.7	0.6 1.9	2.8
Claw 4 lengths
Anterior primary branch	4	10.4 – 12.2	36.6 – 56.9	11.3 44.6	0.9 8.7	11.9
Anterior base + secondary branch	2	9.2 – 9.6	32.9 – 33.0	9.4 33.0	0.3 0.1	?
Anterior spur	2	4.0 – 4.1	14.0 – 14.4	4.0 14.2	0.1 0.2	?
Posterior primary branch	4	10.5 – 12.9	31.3 – 59.7	11.5 41.5	1.0 12.5	11.3
Posterior base + secondary branch	3	8.3 – 9.0	21.8 – 32.0	8.7 27.4	0.3 5.2	9.2
Posterior spur	2	4.3 – 4.7	10.5 – 16.9	4.5 13.7	0.3 4.5	?