Minibiotus keppelensis, 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 : 143-148

Minibiotus keppelensis n.sp.

Figs. 10, 19c; Table 9

Type material. HOLOTYPE in AM ( AM KS41495 ): Australia, Queensland: Great Keppel Island , 23°10'S 150059'E, 14 July 1993, P.D. Claxton . PARATYPES (4 specimens, 2 eggs in AM [ AM KS41496 - KS41501 ]; 13 specimens, 4 eggs in SKC) same data as holotype .

Diagnosis. Cuticle smooth with 10transverse rows of round pores and granulation on all legs; 3 small round macroplacoids and anindistinct microplacoid; robust claws with long, low accessory claws and smooth lunules.

Description. Body length 180-287 /lm, colourless, some specimens with red pigment granules. Eye spots large, in posterior position. Cuticle smooth with. round (1 /lm) pores arranged in ten distinct transverse bands around body and on legs. Fine granulation on top and both sides of claws on first three pairs of legs and on back and sides of fourth pair of legs. Buccal tube very narrow (5.8% of buccal tube length). Stylet supports inserted at 60.6% of the buccal tube length, ventral support short (40.4% of buccal tube length). Pharyngeal bulb oval to round (27x30 /lm), placoids in anterior half; containing three macroplacoids and a microplacoid. Macroplacoid row short (26.6% of buccal tube length); macroplacoids small, granular as are apophyses which are about the same size as the first macroplacoid. First macroplacoid round, slightly elongated anteriorly where it lies beneath the apophysis; second macroplacoid granular smaller than other two; third macroplacoid granular but with slight caudal bulb which curves towards midline. Microplacoid small, indistinct and lies very close to third macroplacoid. Claws robust (fourth pair of claws is 30.1% of buccal tube length) with large refractive zone at base and with long secondary branch; long accessory claws lie close to main branch on all claws. Lunules small, smooth on all claws.

Eggs colourless, round, diameter without processes 45-55 /lm, with processes 65-85 /lm. Eleven processes around circumference and 24 in hemisphere. Processes short cones with pointed apices 11-16 /lm high, base diameter 9-12 /lm and 4-6 /lm-apart. Base of each process surrounded by about ten pores. Membrane around each process reaching half way up the side and apparently supported in between processes by struts (4 /lm high) so that the shell surface appears dotted.

Etymology. The species is named after the type locality, Great Keppel Island.

Remarks. The eggprocesses ofthis species are very similar to those of M. maculartus but the adult differs from that species by having rows of large pores around the body.

Habitat. The species was found in foliose lichen on rock and in crustose lichen on a dead tree in open woodland.

Minibiotus asteris n.sp.

Figs. 11 , 19d ; Table 10

Type material. HOLOTYPE in AM ( AM KS41502 ): Australia, Tasmania: O'Neill's Creek, Mount Roland Protected Area , 41°29'S 146°15'E, 680 m a.s.l., 21 May 1996, A. Moscal . PARATYPES (5 specimens, 3 eggs in AM [ AM KS41503 - KS4151 O]; 80 specimens, 17 eggs in SKC) same data as holotype .

Additional material examined. AUSTRALIA TASMANIA: Mount Montgomery 41°09'S 146°47'E, 470 m, 20 October 1994, A. Moscal, moss on rock in low woodland, 11 specimens in SKC . Hartz Mountains, 43°25'S 146°47'E, 4 December 1988, A.J. Downing, moss on mudstone in Eucalyptus / Myrtle forest, 6 specimens, 3 eggs in SKC . VICTORIA: Melba Gully, Otway Ranges , 38°40'S 143°20'E, 4 May 1997, S.K. Claxton, leafy liverwort, moss and lichen on fallen branches in Nothofagus forest, 33 specimens, 2 eggs ( SKC) . MACQUARIE ISLAND: Scobie Lake , 400 m, 9 December 1977, D.S. Homing, 26 specimens. Gadget's Gully , 220 m, 25 November 1977, D.S.H., 17 specimens. Lusitania Bay , 400 m, 1 December 1977, D.S.H., 7 specimens. Mount Hamilton summit , 433 m, 17 January 1978, D.S.H., 8 specimens. Mount Waite summit , 452 m, 29 December 1977, D.S.H., 11 specimens. Mount Fletcher summit , 428 m, 17 February 1978, D.S.H., 8 specimens. All Macquarie Island specimens in WM . NEW ZEALAND, SOUTH ISLAND: Temple Basin Lower Ski Huts, Arthur's Pass National Park , 19 May 1970, D.S. Homing, 2 specimens ( NZI86 , 188 ). Pegley Flat, Arthur's Pass National Park , 18 May 1970, D.S.H., 1 specimen ( NZI70 ). Fox Glacier Valley , 28 March 1970, D.S.H., 3 specimens (NZ23) in NZM.

Diagnosis. Cuticle smooth with irregularly shaped pores over the whole cuticle and granulation on fourth pair of legs only; 3 small round macroplacoids and a distinct microplacoid; short, robust claws with high accessory claws and smooth lunules.

Description. Body length 128-361 /illl, colourless. Eye spots in posterior position. Cuticle over the whole body is covered with small round (0.5--0.7 /illl) pores; larger pores (about 2 /illl) with irregular shape rare but more common towards the rump. Fine granulation around claws on fourth pair of legs only. Buccal tube narrow (8% of buccal tube length). Stylet supports inserted at 63.8% of buccal tube length, ventral support short (44.8% of length of buccal tube). Pharyngeal bulb round (26 /lm diameter) containing well-developed granular apophyses, three macroplacoids and a microplacoid. Macroplacoid row short (30% of buccal tube length); macroplacoids equal in size; firstmacroplacoid granular, lying close to apophysis and partly obscured by it; second macroplacoid granular as is third which has a slight bulb at the caudal end that curves towards the midline. Microplacoid short, distinct and lies close to third macroplacoid. Claws robust (fourth pair of claws is 28% of buccal tube length) with smallrefractive zone at base and long secondary branch; accessory claws short and rising well clear of main branch. Lunules small and smooth on all claws.

Eggs colourless, round, diameter without processes 54- 67 /lm, with processes 64-85 /illl. 20-28 processes around circumference, 75-90 in ahemisphere. Processes like those

of Macrobiotus hufelandi but with distal disk consisting of about six (up to eight) distinct arms like those of a starfish. Process height 5-10 /illl, base diameter 4.3-7.0 /lm and disk diameter 4.3-5.4 /lm. Processes are 2-4 /illl apart. 12-14 small pores around the base of each process. Egg shell surface smooth or lightly striated.

Etymology. Latin aster with masculine ending is, star, describes the appearance of the distal end of the egg processes.

Remarks. This species is probably most closely related to Macrobiotus allani Murray, 1913 as far as is possible to tellfrom the original description. It differs from that species by having eyes, pores in the cuticle, a strong microplacoid and by the nature and number of disk arms on the egg processes.

Habitat. At the type locality the species was found in mosses and liverworts on soil and rocks on a northwest gully slope in a wet Eucalyptus delegatensis forest.

Minibiotus milleri n.sp.

Figs. 12, 16b, 1ge; Table 11

Type material. HOLOTYPE in AM ( AM KS41599 ): Australia, New South Wales: New England National Park , 30030'S 152°24'E, 1450 m a.s.l., 18 December 1994, S.K. Claxton . PARATYPES (7 specimens, 4 eggs in AM [ AM KS41600 - KS41608 ]; 56 specimens, 4 eggs in SKC) same data as holotype but some also collected on 20 April 1995 and 7 January 1996 .

Additional material examined. NEW SOUTH WALES: Cambewarra Mountain , 34°48'S 150035'E, 625 m, 9 May 1993, S.K. Claxton, moss and lichen on rocks and trees in cool temperate rainforest, 14 specimens in SKC .

Diagnosis. Smooth cuticle with fine granulation near claws, long bean-shaped macroplacoids and a distinct microplacoid; robust claws with short, high accessory claws and smooth lunules.

Description. Body length 149-398 /lm, colourless. Eye spots in the posterior position consisting of large granules.

Cuticle smooth, fine granulation around claws on all legs. Oral cavity long with single tooth ventrally just above stylet sheaths in some larger specimens. Buccal tube narrow (pt 9.7); stylet supports inserted at 73% of buccal tube length; ventral support very short (pt 36.4). Pharynx round (27 /lm diameter) containing small apophyses, three macroplacoids and a microplacoid. Macroplacoid row long (37%

of buccal tube length); first macroplacoid smallest, somewhat pear-shaped, lying close to apophysis and partly obscured by it; second granular, slightly longer than first; third longest. Microplacoid long, distinct, lying close to third macroplacoid. Claws robust (fourth pair of claws is

26.5% of buccal tube length) with long secondary branch, well divided. Round refractive zone at base of claws well developed. Accessory claws short, raised high above main branch. Lunules on first three pairs of legs very small, smooth; on fourth pair smooth.

Eggs round, diameter without processes 68-74 /llll, with processes 90-98 /lm. 20-30 processes around circumference, 80-120 in hemisphere. Processes long cones tapering to blunt tip, rarely bifurcate, lower part of each cone indented and enclosed in membrane. Tapering portion above withrough surface which appears as transverse lines. Process height 10-14 /lm, base diameter 3 /lm arranged evenly about 3 /llll apart. Shell surface faintly striated.

Etymology. The species is named after Dr William R. Miller, friend and colleague.

Remarks. This species is similar to M. hufelandioides and M. aquatilis in having a long macroplacoid row, stylet supports inserted a long way down the buccal tube and no bend in the tube as it enters the pharynx but may be distinguished from these species by its very short ventral support.

Habitat. At the type locality, specimens were recovered from moss on rock, moss and lichen on tree trunks and branches in cool temperate rainforest and Banksia collina thickets.

Figures

Figure 11. Taxonomic details of Minibiotus asteris n.sp. a, habitus (ho1otype); 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.

Figure 19. Eggs of a, Minibiotus pilatus DIC; b, Minibiotus ethelae SEM; c, Minibiotus keppelensis DIC; d, Minibiotus asteris Phase; e, Minibiotus milleri DIC; C, Minibiotus hufelandioides SEM. (Scale bars a-e = 10 f..I1ll, scale bar f = 1 f..I1ll).

Tables

Table 9. Measurements (in flm) of adults of Minibiotus keppelensis n.sp.

Character	No.	Range	Mean	SD	SEHolotype
bodylength	12	200-287	259.4	25.4	7.3	270
BTlength	12	24.9-28.4	26.9	1.2	0.3	27.0
BTwidth	12	1.4-1.7	1.6	0.08	0.02	1.5
SIlength	12	15.1-17.3	16.3	0.8	0.2	16.2
VSlength	12	9.7-11.9	10.9	0.7	0.2	10.8
PRlength	12	7.6-8.7	8.1	0.4	0.1	8.1
MPRlength	12	7.0-7.6	7.2	0.2	0.07	7.0
ml	12	1.6-2.7	2.2	0.3	0.08	2.2
m 2	12	1.6-2.2	1.8	0.2	0.06	1.9
m 3	12	1.6-2.2	2.0	0.3	0.08	2.2
microplacoid	12	0.5-0.8	0.6	0.1	0.03	0.5
PHlength	11	24.0-30.0	26.7	2.2	0.7	27.0
PHwidth	11	23.0-31.0	27.6	2.9	0.9	30.0
clawI	12	6.0-7.0	6.7	0.4	0.1	7.0
clawII-III	12	6.5-7.6	7.3	0.4	0.1	7.6
clawIV	12	7.0-8.6	8.1	0.6	0.2	8.6

Table 10. Measurements (in Ilm) of adults of Minibiotus asteris n.sp.

Character	No.	Range	Mean	SD	SE Holotype
bodylength	20	155-368	259.7	62.8	14.0	274
BTlength	20	21.6-30.8	26.7	3.0	0.7	28.1
BTwidth	20	1.6-2.8	2.1	0.3	0.07	2.2
SIlength	20	13.5-19.5	17.0	2.0	0.5	18.1
VSlength	20	9.7-14.1	12.0	1.4	0.3	12.4
PRlength	20	7.0-11.9	9.4	1.4	0.3	9.2
MPRlength	20	6.0-10.3	8.0	1.2	0.3	8.1
ml	20	1.6-3.2	2.4	0.5	0.1	2.4
m 2	20	1.6-2.7	2.2	0.4	0.09	2.4
m 3	20	1.6-2.7	2.2	0.4	0.09	2.4
microplacoid	20	0.7-1.4	1.1	0.2	0.04	0.8
PHlength	20	22.0-33.0	26.7	3.5	0.8	27.0
PHwidth	20	22.0-36.0	26.5	3.6	0.8	27.0
clawI	20	4.9-7.6	6.3	0.9	0.2	7.0
clawII-III	20	5.4-8.2	6.9	0.9	0.2	7.6
clawIV	20	6.0-8.9	7.5	1.0	0.2	8.1

Table 11. Measurements (in flm) of adults of Minibiotus milleri n.sp.

Character	No.	Range	Mean	SD	SE Holotype
bodylength	20	182-398	272.6	60.2	13.5	349
BTlength	20	24.3-35.1	29.1	3.3	0.7	31.9
BTwidth	20	2.3-3.5	2.8	0.4	0.09	3.2
SIlengtb	20	17.3-26.0	21.2	2.5	0.6	23.0
VSlength	20	8.7-12.7	10.6	1.3	0.3	11.9
PRlength	20	10.8-15.7	12.9	1.5	0.3	14.1
MPRlength	20	8.7-13.0	10.8	1.3	0.3	11.4
m 1	20	2.2-3.2	2.7	0.3	0.07	3.0
m2	20	2.4-3.5	2.9	0.3	0.07	3.2
m 3	20	2.7-4.1	3.4	0.5	0.1	3.5
microplacoid	20	0.8-1.9	1.4	0.3	0.07	1.6
PHlength	20	23.0-35.0	27.7	2.8	0.6	29.0
PHwidtb	20	23.0-33.0	26.8	2.7	0.6	27.0
clawI	20	4.9-7.6	6.4	0.9	0.2	7.0
clawII-I1I	20	5.4-8.7	7.0	0.9	0.2	7.6
clawIV	20	6.5-9.7	7.7	1.0	0.2	8.7