Macrobiotus sicheli, Binda, Maria Grazia, Pilato, Giovanni & Lisi, Oscar, 2005

Binda, Maria Grazia, Pilato, Giovanni & Lisi, Oscar, 2005, Remarks on Macrobiotus furciger Murray, 1906 and description of three new species of the furciger group (Eutardigrada, Macrobiotidae), Zootaxa 1075, pp. 55-68: 65-67

publication ID

http://doi.org/ 10.5281/zenodo.273289

publication LSID

lsid:zoobank.org:pub:E32D6CD0-46BE-43FB-AD50-CEB09B207561

persistent identifier

http://treatment.plazi.org/id/6656879B-9668-FF97-FEEF-A93F181BFB6E

treatment provided by

Plazi

scientific name

Macrobiotus sicheli
status

sp. nov.

Macrobiotus sicheli  sp. nov. ( Fig. 5View FIGURE 5)

Type locality. South Africa, Tzitzikama (an undetermined moss sample).

Material examined. South Africa, Tzitzikama: holotype, 29 paratypes and 7 eggs.

Type repository: Collection of Binda and Pilato: Department of Animal Biology “Marcello La Greca”, University of Catania.

Binda (1984) attributed to M. furciger  specimens and eggs from South Africa; some differences with respect to the description of this species were attributed to the individual variability. We compared the material from South Africa with specimens of M. furciger  from the South Georgia described above, and noted some differences that induce us to attribute the South African specimens to a new species here described and named M. sicheli  sp. nov.

Description of the holotype. Body length 329 m; colourless, eyes present, cuticle with small dots difficult to see ( Fig. 5View FIGURE 5 C). Buccopharyngeal apparatus of Macrobiotus  type ( Fig. 5View FIGURE 5 A); mouth terminal with ten peribuccal lamellae; buccal cavity wall with an anterior band of fine teeth, a posterior crown of triangular teeth and three dorsal and three ventral transverse ridges. Also some supplementary teeth present. Buccal tube 45.4 m long and 8.3 m wide (pt = 18.3). Stylet supports inserted on the buccal tube at 80 % of its length (pt = 80). The pharyngeal bulb (46.3 m x 32 m) has pharyngeal apophyses, three rod­shaped macroplacoids and microplacoid. First macroplacoid 7.4 m long (pt = 16.3), second 6.1 m (pt = 13.4), third, with a preterminal narrowing, 7.3 m (pt = 16.1), microplacoid 5.2 m long (pt = 11.4); entire placoid row 27.7 m long (pt = 61.0), macroplacoid row 21.8 m long (pt = 48.0).

The claws, of the hufelandi type, are short with accessory points on main branches ( Fig. 5View FIGURE 5 B). External claws of third pair of legs 9.5 m long (pt = 20.9). The unfavourable orientation does not allow measurement of other claws; in Table 1 the length of claws of a paratype 230 m long is indicated. Smooth lunules are present; a cuticular thickening is present near the lunules on the first three pairs of legs.

The eggs ( Fig. 5View FIGURE 5 D, E), freely laid, are spherical with trunco­conical processes with the extremity divided (the division may be dichotomic or multiple); the diameter is 66–85.5 m excluding the processes, 82–95 m including them. The processes, 15–23 in the circumference, have a large basal portion and a narrower terminal portion divided twice or thrice (more rarely once) at the apex; the branches are therefore short, and the terminal branches very short ( Fig. 5View FIGURE 5 D). Process surface smooth without refracting areas. The processes in the largest measured egg are 6.5–7.8 m high, the basal diameter in the same egg is 7.9–12.2 m .. The base of each process has a crown of projections forming a very evident crown of dots. The egg shell is dotted; some dots may be contiguous to one another and form a trace of an irregular reticular design ( Fig. 5View FIGURE 5 E).

Etymology. The name sicheli  is in honour of Prof. Giovanni Sichel, cellular biologist of University of Catania and our friend.

Remarks. Macrobiotus sicheli  sp. nov. differs from M. furciger  in the following features: cuticle finely dotted; wider buccal tube ( Table 1); stylet supports inserted on the buccal tube in a more caudal position (pt = 79.3 –80.0 in M. sicheli  sp. nov., 76.2–77.1 in M. furciger  ); third macroplacoid about long as the first one ( Table 1); claws shorter ( Table 1); accessory points less developed; and in some characters of the egg (smaller dimensions; processes shorter, without refracting areas, divided only in the terminal portion and therefore with branches shorter; basal crown of projections more evident; egg shell with more evident dots but without a true, regular, reticular design).

The new species differs from M. aradasi  sp. nov. in the following features: cuticle finely dotted; buccal armature with anterior band of teeth present; posterior crown of teeth more developed; wider buccal tube ( Table 1); stylet supports inserted on the buccal tube in more caudal position (pt = 79.3 –80.0 in M. sicheli  sp. nov., 72.0– 72.8 in M. aradasi  sp. nov.); microplacoid slightly longer ( Table 1), claws shorter ( Table 1) with accessory points less developed; and in some characters of the eggs (egg processes divided only in the terminal portion and therefore with branches clearly shorter; basal projections forming a more evident basal crown of dots; egg shell with more evident dots but without a true, regular, reticular design).

Macrobiotus sicheli  sp. nov. differs from M. divergens  sp. nov. in the following features: cuticle finely dotted; eyes present; stylet sheaths normally shaped, i.e., not very thick and with the caudal portion not diverging from the buccal tube walls; stylet supports inserted on the buccal tube in a more caudal position (pt = 79.3 –80.0 in M. sicheli  sp. nov., 74.9–77.5 in M. divergens  sp. nov.); microplacoid more developed ( Table 1); claws with accessory points less developed; and in some characters of the eggs (processes more developed, divided only in the terminal portion and therefore with branches shorter; basal projections more developed and forming a more evident crown of basal dots; egg shell with more evident dots but without a true, regular, reticular design).