Minibiotus ethelae, 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 : 140-143

Minibiotus ethelae n.sp.

Figs. 9, 19b; Table 8

Type material. HOLOTYPE in AM ( AM KS41484 ): Australia, New South Wales: Cobbitty , 34°01'S 150040'E, 90 m a.s.1., 20 March 1994, E.S. Siebels . PARATYPES: same data as holotype but collected on 8 November 1985, 11 May 1991, 29 August 1992 and 20 March 1994, 7 specimens, 3 eggs in AM ( AM KS41485 - KS41494 ) ; 50 specimens, 19 eggs in SKC ; 1 specimen, 1 egg in collection of Binda and Pilato ( UCI) .

Additional material examined. SOUTH AFRICA: Lydenberg, Transvaal, 2250 m, 6 May 1988, M. Filmer, lichens, 11

specimens, 2 eggs in NMP . Natal , Drakensberg , Cathedral Rock Area, 30 May 1988, H. Dastych, moss onrockin Indumeni forest, 4 specimens in NMP . Rus-Te-Winter National Reserve , 1500 m, 30 May 1988, M. Filmer, bark ofAcacia, 2 specimens ( NMP). Kruger National Park, 20 May 1988, S. Neses, lichens on dead twigs, 8 specimens in ZIM . Hendriksdaal , Palmers Creek, 1400 m, July 1971, A. Szeptycki, rock, 1 specimen in ZIM .

Diagnosis. Pale yellow body cells and variably shaped pores in the cuticle, cuticle thickened in caudal region; 3 small round macroplacoids and an indistinct microplacoid; long, slender claws with low accessory claws and smooth lunules.

Description. Body length 175-480 /lm, yellow body cells. Large, posterior eye spots present. Cuticle with nine transverse bands of large pores (round, elliptical, trifoliate and quadrifoliate) around the body; pores also on the legs. Cuticle thickened in the caudal region. Buccal tube narrow (7.6% of buccal tube length). Stylet supports inserted at 64.9% of buccal tube length and ventral support 51.4%. Pharyngeal bulb round (about 32 /lm diameter) containing large round apophyses, three macroplacoids and a microplacoid. Macroplacoid row short (32.3% of buccal tube length); first macroplacoid pear-shaped and partly obscured by apophysis, second granular and smaller than the other two and third granular with caudal bulb that curves towards midline. Microplacoid small, indistinct and lies very close to third macroplacoid. Claws slender (fourth pair of claws is 37.6% of length of buccal tube) with small but obvious refractive zone at base and long secondary branch; short but well developed accessory claws lie close to main branch. Lurtules small, smooth and thin on all claws.

Eggs colourless, round, diameter without processes 67-70 /lm, with processes 90-100 /lm. 28-34 processes around circumference and 120-160 in hemisphere. Processes are cones tapering rapidly to attenuated tip, often bifurcate. Process height variable, on one egg 12- 14 /lm, on three others 14.5-19 /lm and on another 19- 22.5 /lm. Base diameter of processes 2.7-3.8 /lm (on egg with longest processes 4.3-4.9 /lm), about 5 /lm apart. Shell surface dotted, SEM shows these to be bumps ( Fig. 19b ).

Etymology. The species is named after Ethel Siebels who kindly assisted in the collection of the specimens.

Remarks. The species is similar to Minibiotus furcatus but differs from itby having the stylet supports inserted more anteriorly, by having a much shorter ventral support and shorter placoids, by having smooth lunules on all legs and having much longer egg processes and a dotted shell. It differs fromMinibiotus ramazzottii Binda & Pilato, 1992 by having large showy pores in the cuticle and from Minibiotus vinciguerrae Binda & Pilato, 1992 by having no granulation around the claws and longer, thinner egg processes.

Habitat. At the type locality the species was found in crustose and foliose lichens on the trunk of a Casuarina tree and a peppercorn tree in a suburban street.

Figures

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).