Minibiotus hispidus, 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 : 138-139

Minibiotus hispidus n.sp.

Figs. 7 , 18f ; Table 6

Type material. HOLOTYPE in AM ( AM KS41467 ): Australia, Queensland: Crow's Nest , 27°16'S 152°03'E, 3 September 1985, S.K. Claxton . PARATYPES (6 specimens, 4 eggs in AM [ AM KS41468 - KS41477 ]; 24 specimens, 5 eggs in SKC): same data as holotype .

Additional material examined. AUSTRALIA, New South Wales: Appin , 34°12'S 150047'E, 29 June 1985, P.D. Claxton, moss and lichen on sandstone rock in open forest, 30 specimens, 5 eggs . Queensland: North Stradbroke Island , 27°30'S 153°30'E, 19 February 1996, RM . Kristensen, soil under Eucalyptus tree, 10 specimens. Isla Gorge , 25°lO'S 149°56'E, 7 March 1996, RM . Kristensen, moss on rock, 8 specimens, 1 egg. Bribie Island , 27°30'S 153°08'E, 16 April 1995, S.K. Claxton, leaf litter and sand in Banksia heath, 21 specimens, 1 egg . Western Australia: John Forest National Park , 31°53'S 116°05'E, 22 November 1994, P.D. Claxton, moss and lichen on rock in open forest, 27 specimens, 1 egg. (All SKC) . NEW ZEALAND: South Island , (NZ526) Canaan Rd, Abel Tasman National Park , 9 April 1971, D.S. Homing, 2 specimens in NZM .

Diagnosis. Smooth cuticle with granulation on all legs, 3 small round macroplacoids and an indistinct microplacoid; slender claws with short, low accessory claws and smooth lunules.

Description. Body length 160-350 /lm, colourless. Eye spots in posterior position. Cuticle smooth, coarse

granulation on top and sides of first three pairs of legs above claws and around claws onfourth pair oflegs. Buccal tube narrow (8% of the buccal tube length). Stylet supports inserted at 65.2% ofbuccal tube length, ventral reinforcing bar very short, 45.7%. Pharyngeal bulb round (about 28 /lm diameter) containing large granular apophyses, three granular macroplacoids and a microplacoid. Macroplacoid row short (33.2% of buccal tube length); macroplacoids almost equal in size, first somewhat pear-shaped, lying close to apophysis and partly obscured by it, second is granular and third granular with a faint caudal knob turned towards the midline. Small, indistinct microplacoid lies close to third macroplacoid. Claws slender (fourth pair of claws is 28.1% of length of buccal tube) with small refractive base and long secondary branch.Accessory claws shortand rise high above main branch. Lunules on all claws small and smooth, somewhat thickened on fourth pair.

Eggs round, colourless, diameter without processes 59 f1l1l, with processes 72 f1l 1l. 48 processes around circumference, about 340 in hemisphere. Processes small cones with fine tips, height 6.5-8.4 f1l1l, base diameter 2.8 f1l1l and 1-2 f1l1l apart. Ring of very small pores around base of each process. Shell appears to be covered with very small pores of uniform size.

Etymology. Latin, hispidus , bristly, prickly, describing the appearance of the egg.

Remarks. The population from Appin, NSW is smaller than the type population from Crow's Nest (mean body length 213.6 /lm, SD 41.5 f1l1l, n = 15) as is that from Perth (mean body length 196.9 /lm, SD 36.4 /lm, n = 16) but otherwise the adults are the same. Egg processes from the Appin population are slightly longer (10 f1l1l) and further apart (3.3 f1l1l) than those of the type population. The single egg from Perth has quite narrow processes (1.5-2 f1l1l base diameter).

The species is very similar to Minibiotus maculartus but has a shorter ventral support and smooth lunules on

the fourth pair of legs. It is perhaps most closely related to Macrobiotus crassidens Murray, 1907 (based on the somewhat inadequate description ofthat species) but differs from it by having eyes, by having a very indistinct microplacoid and by having egg processes thatare narrower at the base, shorter and not touching.

Habitat. At the type locality the species was found in mosses and lichens on rocks and fallen logs in open woodland. At other Australian localities it was found in moss and lichen on rocks in open woodland but also can be found in leaf litter and sandy soil. The species can cope with high temperatures and drying.

Figures

Figure 7. Taxonomic details of Minibiotus hispidus n.sp. a, habitus (holotype); 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 18. Eggs of a, Minibiotus intermedius DIC; b, Minibiotus taiti DIC; c, Minibiotus poricinctus Phase; d, Minibiotus Jloriparus Phase; e, Minibiotus aquatilis Phase; f, Minibiotus hispidus DIe. (Scale bars = 10 J..Illl).