Minibiotus hufelandioides (Murray, 1910) Claxton, 1998

Claxton, Sandra K., 1998, A revision of the genus Minibiotus (Tardigrada: Macrobiotidae) with descriptions of eleven new species from Australia, Records of the Australian Museum 50 (2), pp. 125-160 : 148-152

Minibiotus hufelandioides (Murray, 1910) n.comb.

Figs. la, 13, 19f; Table 12

Macrobiotus hufelandioides Murray, 1910: 138-139 , pI. XVIII, figs. 29a-c.

Material examined. Australia: NEW SOUTH WALES: Kosciusko (type locality), Digger's Creek , 36°20'S 148°30'E, 1500 m, 1 October 1992, P.D. Claxton, moss and lichen on rock in open alpine area, 58 specimens, 16 eggs. Thredbo Creek , 36°27'S 147°55'E, 1200 m, 1 October 1992, P.D.C., moss and lichen on rock in open alpine area, 10 specimens, 1 egg. Waste Point, 36°20'S 148°36'E, 1000 m, 1 October 1992, P.D.C., moss and lichen on rock, 4 specimens, 1 egg. Lake George , 35°04'S 149°23'E, 27 March 1992, P.D.C., moss and lichen on rock in open forest, 29 specimens, 24 eggs. Galore, 35°07'S 146°47'E, 340 m, 19 March 1994, S.K.C., moss and lichen on rocks on summit of monolitb in open forest, 19 specimens, 1 egg. All SKC .

Diagnosis. Smooth cuticle with granulation on all legs; three long macroplacoids and an indistinct microplacoid; robust claws with long, high accessory claws and toothed lunules on fourth pair of claws.

Description. Body length 149-419 /llll, colourless. Eyes large, posterior. Cuticle smooth except for strong granulation over back and outside of all legs around claws. Buccal tube narrow (8.6% of buccal tube length). Stylet supports inserted at 67.4% of buccal tube length, ventral support short (45.9% ofbuccal tube length). Pharynxround (30 /lm diameter) containing large apophysis, three macroplacoids and a microplacoid. Macroplacoid row long (38.2% of buccal tube length); first macroplacoid pearshaped and partly obscured by apophysis; second macroplacoid round, slightly shorter than other two; third macroplacoid kidney-shaped and about same size or slightly longer than the first. Microplacoid indistinct and lies close to third macroplacoid. Claws long and robust (fourth pair of claws is 29.3% of buccal tube length) with large, clear refractive base and short secondary branch. Accessory claws long andhigh above main branch. Lunules small and smooth on first three pair of legs, jagged or toothed on fourth pair.

Eggs colourless, round, diameter without processes 54- 64 /llll, with processes 65-75 /llll. 20-26 processes around circumference. Processes conical with expanded discoid tops, distal disk smooth or lightly notched; process height 5.5-6.5 /lm, base diameter 5.5-7 /lm, disk diameter 4.5- 6.5 /lm. Each process with a ring of pores around the base; shell surface lightly granulated.

Remarks. The original type material was not located. The main repository of lames Murray's permanent slides is the Royal Scottish Museum, Edinburgh ( Morgan, 1977). No Australian tardigrades are represented in that collection.

Although Murray's description lacks detail such as the granulation around the claws and the toothed lunule on the fourth pair oflegs, the identification of these specimens and eggs is not in doubt. His description of the animal having "three rods in the pharynx of nearly equal size, ... no comma or a very small and obscure one, ... eggs with processes like those of the typical hufelandi egg, processes taper from a broad base which is surrounded by a circlet of dots... agrees with the specimens described here.

Habitat. Murray (1910) indicated that the species was found in mosses at the Hospice on Mount Kosciusko. The material obtained for this study was found in mosses, fruticose and foliose lichens on rocks at the site of the Hospice (Digger's Creek). This species was the most abundant of the 31 species collected at Kosciusko in October 1992.

Minibiotus aculeatus (Murray, 1910) n.comb.

Figs. 1b , 14 , 16a, 17a, 20a; Table 13

Macrobiotus aculeatus Murray, 1910: 139-140 , pI. XVIII, figs. 27a-e.

Macrobiotus intermedius subjulietae Homing, Schuster & Grigarick, 1978: 237 , figs. 117-120.

Material examined. AUSTRALIA: NEW SOUTH WALES: Kosciusko (type locality), Digger's Creek , 36°20'S 148°30'E, 1500 m, 1 October 1992, P.D. Claxton, moss on rock, 1 specimen. Thredbo Creek , 36°27'S 147°55'E, 1200 m, 1 October 1992, PD . C., lichen on rock, 7 specimens, 1 egg. Waste Point , 36°20'S 148°36'E, 1000 m, 1 October 1992, PD . C., lichen on rock, 1 egg. New England National Park , 30030'S 152°30'E, 1400 m, 18 December 1994, S.K. Claxton, moss and lichen on rocks and trees in Banksia heath, 36 specimens, 2 eggs; ditto but collected 20 April 1995, S.K.C., moss and lichen on rock in heath, 13 specimens, 1 egg ; ditto but collected on lichen on tree in Nothofagus forest, 1 specimen ; ditto but collected 7 January 1996, S.K.C., moss and lichen in heath, 91 specimens, 4 eggs. Jenolan , 33°49'S 150002'E, 14 December 1986, S.K.C., moss on trees androcks in sheltered valley, 22 specimens, 6 eggs. Barrington Tops , 31°59'S. 151°30'E, 8 February 1993, D. Clark, moss on branch on ground in closed forest, 1 specimen. Mount Wilson , 33°30'S 150023'E, 27 October 1991, S.K.C., moss on tree in cool temperate rainforest, 1 specimen, 1 egg. QUEENSLAND: Ravensboume , 27°22'S 152°08'E, 3 September 1985, S.K.C., moss on tree in closed forest,S specimens. LORD HOWE ISLAND , D.S. Homing, 6 specimens. TASMANIA: Mount Pedder, Maria Island National Park , 42°38'S 148°05'E, 620 m, 20 April 1995, A. Moscal, moss on rock in heath, 7 specimens. All SKC .

NEW ZEALAND: 16 paratypes of Macrobiotus intermedius subjulietae : NORTH ISLAND: Waimaua Gorge, 17 May 1971, c. J. Homing, 1 specimen (NZ650). Grays Bush, 19 May 1971, C. J.H., 1 specimen ( NZ 672). Bruce Park Scenic Reserve, 21 May 1971, D.S. Homing, 3 specimens (NZ705). Taumarunui, 15 July 1970, BJ. Donovan, 2 specimens ( NZ 279, NZ281). Norsewood, 20 May 1971, D.S.H., 1 specimen ( NZ 687). Mount Egmont National Park, 23 May 1971, D.S.H., 1 specimen (NZ753). Morere Hot Spring Scenic Reserve , 19 May 1971, D.S.H., 1 specimen ( NZ 674). SOUTH ISLAND: Abel Tasman National Park ,

9 April 1971, D.S.H., 1 specimen ( NZ 538). Cowper's Knob , 9 April 1970, D.S.H., 1 specimen ( NZ 86). West Harper Hut , 12 April 1971, H.A. Best, 1 specimen ( NZ 544). CHATHAM ISLAND : Waterfall Creek , 31 August 1971, D.S.H., 2 specimens ( NZ 932, NZ 924). THREE KINGS ISLAND : Summit Ridge, 28 November 1970, G.w. Ramsey, 1 specimen ( NZ 479). All NZM

Diagnosis. Smooth cuticle with pores of variable size and shape and three pairs of soft spines (Fig. 17a) over legs 11, III and IV (or one pair over leg IV); three small round macroplacoids and a distinct microplacoid; short, robust claws with prominent accessory claws and very small refractive base and lunules.

Description. Body length 204-350 /lm most specimens pink or pale brown in colour. Eyes in the posteriorposition. Cuticle covered with small (0.5 /lm diameter) round pores and, more sparsely, large triangular or star-shaped pores; large pores often with thickened rims. A ring of about ten pores around the mouth below the sensory fields are visible only under the highest light magnification and appear as slits in specimens prepared for SEM ( Fig. 1b ). The shape under SEM is probably due to distortion of the specimen during preparation. Three pairs of soft, conical spines (about 7 /lm long) on body, one pair each above the last three pairs of legs. No teeth in oral cavity, buccal tube narrow 2 J.lIll (pt 7.8). Stylet supports inserted at 63.7% of length of buccal tube, ventral reinforcing bar 51.4% of buccal tube length. Pharyngeal bulb oval (27x30 /lm) containing well developed, granular apophyses, three macroplacoids and a microplacoid. Macroplacoid row short (32.2% of buccal tube length); first macroplacoid pearshaped lying close to apophysis and partly obscured by it, second and third macroplacoids granular and similar in size. Microplacoid small, distinct and lies close to third macroplacoid. Claws short, robust (fourth pair of claws is 22.8% of buccal tube length) with no refractive zone at the base; accessory claws long and rising well clear of main branch. Lunules very small.

Eggs colourless, round, diameter without processes 54 Ilm, with processes 65 Ilm. 24-30 processes around circumference, 100 in hemisphere. Processes long cones with attenuated, areolated tips, 9-11 Ilm long, base diameter 3-5 Ilm, processes 3--4 Ilm apart, base of each process indented. Egg shell surface smooth.

Remarks. Type material could not be located (see remarks for M. hufelandioides ) but because of the very characteristic soft spines and the description of the eggs, the identification is not in doubt. Murray's description did not include pores in the cuticle and they are difficult to discern at low magnification. They are mentioned as occurring in the

posterior region of the animal in the description of Macrobiotus intermedius subjulietae . However they are certainly present over the whole cuticle in the 16 paratypes examined as they are in the material from the type locality. Specimens from all sites agree well with the dimensions of thatmaterialincluding the five specimens fromRavensbourne and three from Lord Howe Island which had only one pair of spines above the fourth pair oflegs. (Murray [1910] reported specimens with one pair of spines from Katoomba, NSW).

Habitat. The species can be found in mosses and lichens at sites from high altitudes and seems to have a preference for these substrates on rock rather than on trees.

Figures

Figure 1. a, papulae of Minibiotus hufelandioides SEM; b, suboral pores of Minibiotus aculeatus SEM. (Scale bars = 1 flm).

Figure 14. Taxonomic details of Minibiotus aculeatus a, habitus; b, egg; c, ventral view of the buccal armature; d, claws of the first pair of legs; e, claws of the fourth pair of legs; f, detail of eggshell.

Tables

Table 13. Measurements (in Ilm) of adults of Minibiotus aculeatus.

Character	No.	Range	Mean	SD	SE
bodylength	7	210-350	290.6	43.8	16.6
BTlength	7	24.9-32.4	29.1	2.5	1.0
BTwidth	7	1.9-2.5	2.3	0.2	0.08
SIlength	7	15.7-20.8	18.5	1.7	0.7
VSlength	7	13.0-16.8	15.0	1.4	0.5
PRlength	7	9.7-12.2	11.1	0.9	0.4
MPRlength	7	7.3-10.5	9.4	1.1	0.4
ml	7	2.2-3.2	2.8	0.4	0.1
m 2	7	1.6-2.7	2.3	0.4	0.1
m 3	7	1.6-3.0	2.4	0.5	0.2
microplacoid	7	0.6-1.1	1.0	0.2	0.08
PHlength	7	27.0-34.0	29.6	2.7	1.0
PHwidth	7	27.0-38.0	31.1	3.4	1.3
clawI	7	4.3-6.0	5.6	0.6	0.2
clawII-III	7	4.7-6.5	6.1	0.7	0.3
clawIV	7	5.4-7.0	6.6	0.6	0.2