Paramacrobiotus pius Lisi, Binda & Pilato, 2016, sp. nov.
Creators: name: Lisi, Oscar
name: Binda, Maria Grazia
name: Pilato, Giovanni
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Tardigrada
Eutardigrada
Parachela
Macrobiotidae
Paramacrobiotus
Paramacrobiotus pius

description: Paramacrobiotus pius sp. nov.
(Fig. 5)
Type locality. Gangi (Palermo, Sicily), 37°48′00″ N 14°12′ 00″E. Former monastery of Gangivecchio (Gangi, Palermo) at 850 m a.s.l.: moss sample collected on rock by Pilato & Binda in August 2002.
Material examined. Holotype (slide no. 5562), 7 paratypes (slides no. 5562–3; 5704, 5706–7), and 10 eggs (slides nos. 5562–5563; 5705–5707); some with fully developed embryos.Paramacrobiotus piussp. nov.No. Slide 5562 paratype 5706 newborn 5704 paratype newborn 5704 paratype 5562 holotype 5704 paratype Body length ? ? ? 270 ? Buccal tube length 30.1 30.2 31.1 31.5 34.3 External buccal tube width 5.9 6.1 5.8 6.1 7.3pt19.620.2 18.619.421.3ptstylet supports insertion point77.777.9 76.977.277.9First macroplacoid 3.9 4.8 4.4 4.4 ?pt13.015.9 14.114.0?Second macroplacoid 3.1 3.4 3.4 3.6 ?pt10.311.3 10.911.4?Third macroplacoid 4.4 4.3 4.5 4.5 ?pt14.614.2 14.514.3?Microplacoid 2.4 2.3 2.4 2.5 ?pt8.07.6 7.77.9?Placoid row 16.1 16.0 17.4 17.7 ?pt53.553.0 55.956.2?Macroplacoid row 12.5 12.5 13.4 13.2 ?pt41.541.4 43.141.9?External claw I 8.2 ? 8.7 8.6 ?pt27.2? 28.027.3?Internal claw I 7.7 ? 8.5 8.1 8.7pt25.6? 27.325.725.4External claw II 8.3 ? 8.9 9.2 ?pt27.6? 28.629.2?Internal claw II 7.7 ? ? 8.2 ?pt25.6? ?26.0?External claw III 8.3 ? 8.9 9.2 ?pt27.6? 28.629.2?Internal claw III 7.7 ? ? 8.2 ?pt25.6? ?26.0?Posterior claw IV ? ? ? 9.7 ?pt?? ?30.8?Anterior claw IV ? ? ? 8.9 9.7pt? ? ? 28.3 28.3
Specific diagnosis. Colourless; eye spots absent (also in living specimens), cuticle smooth. Bucco-pharyngeal apparatus of the Macrobiotus type similar to that of Paramacrobiotus richtersi; three macroplacoids and a microplacoid (at a distance from the third macroplacoid) present. Well developed claws of the hufelandi type with accessory points on the main branches and lunules present. Eggs, free laid, with reticulated trunco-conical processes with short terminal thorns; egg shell areolated with clearly sculptured areolae.
Description of the holotype. Body length 270 µm long, colourless; cuticle smooth without pores (only very small dots are present on the legs); eye spots absent; bucco-pharyngeal apparatus of Macrobiotus type (buccal tube rigid with ventral lamina) (Fig. 5 A), mouth terminal with 10 peribuccal lamellae; buccal armature composed of an anterior band of small teeth, a posterior ring of small triangular teeth and, more caudally, three dorsal and three ventral transverse ridges. Rigid buccal tube 31.5 µm long and 6.1 µm wide externally (pt = 19.4) (Table 3); stylet supports inserted on the buccal tube at 77.2 % of its length (pt = 77.2). Pharyngeal bulb with apophyses, three macroplacoids, of almost the same length, and the microplacoid set at a distance from the third macroplacoid, which is a character of the Paramacrobiotus richtersi group (Fig. 5 A); first macroplacoid 4.4 µm long (pt = 14.0); second 3.6 µm (pt = 11.4); third 4.5 µm (pt = 14.3); small microplacoid 2.5 µm long (pt =7.9); the entire placoid row 17.7 µm long (pt = 56.2); the macroplacoid row length 13.2 µm (pt = 41.9). The first macroplacoid does not appear to have a central constriction.
Claws of the Macrobiotus hufelandi type, well developed, slender, with a long basal portion (Fig. 5 B,C). External and internal claws of the first pair of legs 8.6 µm long (pt = 27.3) and 8.1 µm long (pt = 25.7) respectively; those of the second and third pairs of legs 9.2 µm long (pt = 29.2) and 8.2 µm (pt =26.0) long respectively (Table 3); posterior and anterior claws of the hind legs 9.7 µm long (pt = 30.8) and 8.9 µm (pt = 28.3), respectively. Main branches of all claws with thin accessory points (Fig. 5 B, arrow). Smooth lunules present, well developed on the hind legs (Fig. 5 C, arrows); a cuticular bar is present near the base of the claws on the first three pairs of legs.
Remarks. The paratypes are similar to the holotype in both morphological and metric characters; the measurements of some structures of the holotype and four paratypes are given in Table 3.
Eggs: The eggs, free laid, are areolated and have trunco-conical processes (10 around the circumference, 21-22 per hemisphere) (Fig. 5 D). The diameter is 82-88 µm excluding the processes, 105-111 µm including these structures, which are 11.8-12.3 µm high with a basal diameter ca. 20 µm or slightly wider (Table 4). Short spines are more or less visible on the apices of the processes (Fig. 5 D). The processes have a reticular ornamentation (Fig. 5 E) with an elongated mesh (with slightly sinuous margins) near the base, and an isodiametric mesh near the apices; the areolae are sculptured with obvious small tubercles (Fig. 5 F).
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Etymology. The name pius (meaning: holy, devoutly religious) refers to the fact that the population was found in a moss sample collected in the neighbourhood of the ancient former monastery of Gangivecchio (Gangi, Palermo).
Differential diagnosis. As is known, the species of the Paramacrobiotus richtersi group are all very similar and it is often very difficult to identify them without eggs.
Paramacrobiotus pius sp. nov. has a smooth cuticle (only very small dots are present on the legs) and therefore differs from Paramacrobiotus corgatensis (which has very fine dots over dorsal and ventral cuticle) and Paramacrobiotus danielisae (which has a sculptured cuticle, with small polygons); stylet supports are inserted on the buccal tube in a slightly more cephalic position (pt = 76.9-77.7 in Paramacrobiotus pius sp. nov., 80.2-80.7 in Paramacrobiotus corgatensis, 80.2-81.2 in Paramacrobiotus danielisae); higher values of the pt index relative to the claw length (Table 5), and in having conical and shorter egg processes (Figs. 5 D and 6A and 6B). It also differs from Paramacrobiotus corgatensis in the lack of eye spots.
The new species differs from Paramacrobiotus halei by having a smooth cuticle, stylet supports inserted on the buccal tube in a slightly more cephalic position (pt = 76.9-77.7 in Paramacrobiotus pius sp. nov., 81.5 in Paramacrobiotus halei) and higher values of the pt index relative to the claw lengths (Table 5).
The new species differs from Paramacrobiotus savai, Paramacrobiotus danielae and Paramacrobiotus peteri by having higher values of the pt index relative to the claw lengths (Tables 5 and 6), and by having sculptured egg areolae. In addition, it differs from Paramacrobiotus savai and Paramacrobiotus danielae by lacking eye spots, from Paramacrobiotus danielae by having a smooth cuticle and stylet supports inserted on the buccal tube in a slightly more cephalic position (pt = 76.9-77.7 in Paramacrobiotus pius sp. nov., 79.9-80.5 in Paramacrobiotus danielae); it differs from Paramacrobiotus peteri also in the shape of the egg processes (Figs. 5 D and 6C).
The lack of eye spots distinguishes Paramacrobiotus pius sp. nov. from Paramacrobiotus priviterae and Paramacrobiotus sklodowskae; in addition, it differs from the former species by the claw shape (Figs. 5 B,C and 6D), and from Paramacrobiotus sklodowskae by a lower value of the pt index relative to the stylet supports insertion point (76.9-77.7 in Paramacrobiotus pius sp. nov., 81.8-85.2 in Paramacrobiotus sklodovskae).
The new species differs from Paramacrobiotus magdalenae by lacking eye spots, by having higher values of the pt index relative to the claw lengths (Table 6), and by characters of the eggs (shape of processes and shorter processes).
* According to Michalczyk & Kaczmarek (2006). Slide deposited in the Natural History Collections, Faculty of Biology, A. Mickiewicz University, Poznan, Poland.
** Slide deposited in Te Papa Tongarewa, National Museum of New Zealand, Wellington. ***According to Kaczmarek, Michalczyk and Diduszko, 2005.
Paramacrobiotus pius sp. nov. differs from Paramacrobiotus alekseevi by higher values of the pt index relative to the microplacoid length (7.7–8.0 in Paramacrobiotus pius sp. nov., 4.0– 6.2 in Paramacrobiotus alekseevi), different shape of the egg processes, and egg areolae with more obvious ornamentation.
The new species differs from Paramacrobiotus hapukuensis by lower values of the pt index relative to macroplacoid lengths but higher values relative to the microplacoid length (Table 6); slightly higher values of that index relative to the claw lengths (Table 6); egg processes shorter and different in shape, and sculptured egg areolae (Figs. 5 D and 7A).
Paramacrobiotus pius sp. nov. is very similar to Paramacrobiotus gerlachae but differs by slightly higher values of the pt index relative to the external claws and a more marked difference in length between external and internal claws on each leg (Table 6); and overall, in some characters of the egg (small apical spines present, egg areolae with obvious ornamentation, which in comparison is very faint in Paramacrobiotus gerlachae where the central portion of the areolae is thicker than the periphery) (Figs. 5 F and 7B).
The new species differs from Paramacrobiotus vanescens by having smooth cuticle with small dots only on the legs (the original description of Paramacrobiotus vanescens did not report that the whole cuticle was finely dotted (Pilato, Binda & Catanzaro, 1991); however, this characteristic was subsequently stressed by Pilato et al. (2001). In addition, the new species differs from Paramacrobiotus vanescens by having lower values of the pt index relative to the microplacoid (7.7–8.0 in Paramacrobiotus pius sp. nov., and ca. 4 in Paramacrobiotus vanescens: Figs. 5 A and 7C), and in details of the eggs (less indented apices of processes, and areolae with more obvious sculpture: Figs. 5 D-F and 7D).
Paramacrobiotus pius sp. nov. differs from Paramacrobiotus garynahi by lacking cuticular pores; by having slightly higher values of the pt index relative to the claw lengths (Table 6); a different shape of the egg processes, and egg areolae with a more obvious sculpture.
The new species differs from Paramacrobiotus richtersi overall by having slightly lower values of the index pt relative to the stylet supports insertion point (76.9-77.7 in Paramacrobiotus pius sp. nov., 79.2-81.8 in Paramacrobiotus richtersi), and in some characters of the eggs: the egg processes of the new species have small terminal spines (Fig. 5 D) whereas in Paramacrobiotus richtersi they have blunt apices; and the entire surface of the areolae has an obvious reticular sculpture (Fig. 5 F).
Paramacrobiotus pius sp. nov. differs from Paramacrobiotus lorenae by a smooth cuticle, lower value of the pt index relative to the stylet supports insertion point (76.9-77.7 in Paramacrobiotus pius sp. nov. and ca. 81 in Paramacrobiotus lorenae), and in some characters of the eggs (processes with neither elongate nor flexible apices, more evident areolae sculpture).
description: Published as part of Lisi, Oscar, Binda, Maria Grazia & Pilato, Giovanni, 2016, Eremobiotus ginevrae sp. nov. and Paramacrobiotus pius sp. nov., two new species of Eutardigrada, pp. 344-360 in Zootaxa 4103 (4) on pages 351-359, DOI: 10.11646/zootaxa.4103.4.3, http://zenodo.org/record/267185