Macrobiotus binieki, Kaczmarek, Łukasz, Gołdyn, Bartłomiej, Prokop, Zofia M. & Michalczyk, Łukasz, 2011

Kaczmarek, Łukasz, Gołdyn, Bartłomiej, Prokop, Zofia M. & Michalczyk, Łukasz, 2011, New records of Tardigrada from Bulgaria with the description of Macrobiotus binieki sp. nov. (Eutardigrada: Macrobiotidae) and a key to the species of the harmsworthi group, Zootaxa 2781, pp. 29-39 : 31-35

Macrobiotus binieki sp. nov.

FIGURES 1–8 , TABLES 1–2

Material examined: Holotype and 16 paratypes (12 adults + 4 eggs (including two with embryos) were extracted from a moss sample collected from location A (see Material and Methods).

Description. Adult (measurements in Table 1): Body transparent/white ( Fig. 1 ). Eyes present. Cuticle smooth, without pores. Fine, regular granulation present on all legs, developed better on hind legs.

CHARACTER N RANGE MEAN SD Holotype µm pt µm pt µm pt µm pt Body 6 357–647 895–1091 446 965 108 70 379 924 Buccal tube 6 37.2–59.3 – 46.0 – 8.5 – 41.0 – Stylet support insertion point 6 28.6–46.1 74.9–77.8 35.1 76.4 6.6 1.3 31.9 77.8 Buccal tube external width 6 4.6–7.8 12.0–13.2 5.7 12.4 1.2 0.5 4.9 12.0 Buccal tube internal width 6 3.4–5.8 8.3–9.8 4.1 8.8 0.9 0.6 3.5 8.5 Ventral lamina 6 23.7–39.7 63.2–66.9 29.6 64.1 6.1 1.4 25.9 63.2 Macroplacoid 1 6 5.3–8.5 11.8–16.1 6.2 13.6 1.2 1.5 5.3 12.9 Macroplacoid 2 6 3.0–5.3 7.6–8.9 3.9 8.4 0.9 0.6 3.3 8.0 Macroplacoid 3 6 4.2–7.4 10.2–12.5 5.1 11.0 1.3 0.9 4.4 10.7 Microplacoid 6 2.4–4.4 5.5–7.4 2.9 6.2 0.8 0.7 2.4 5.9 Macroplacoid row 6 14.3–24.2 34.4–40.8 17.1 37.1 3.8 2.4 14.9 36.3 Placoid row 6 17.3–29.4 42.3–49.6 20.9 45.2 4.7 2.8 17.9 43.7 Claw 1 - primary branch 5 8.3–12.5 20.2–22.6 9.5 21.4 1.8 1.1 8.3 20.2 Claw 1 - secondary branch 3 5.9–10.6 14.4–17.9 7.9 16.2 2.4 1.7 5.9 14.4 Claw 2 - primary branch 4 8.3–12.8 20.2–24.0 10.1 22.2 2.1 1.6 8.3 20.2 Claw 2 - secondary branch 3 5.9–9.3 15.7–18.6 7.8 16.7 1.7 1.6? ? Claw 3 - primary branch 3 8.5–13.2 22.3–23.7 10.5 22.9 2.4 0.7? ? Claw 3 - secondary branch 2 6.5–11.4 17.5–19.2 9.0 18.3 3.5 1.2? ? Claw 4 - primary branch 5 10.6–15.3 24.6–31.7 12.8 27.5 1.7 3.0 10.6 25.9 Claw 4 - secondary branch 5 7.7–11.4 17.5–25.0 9.5 20.6 1.3 3.1 7.7 18.8 Bucco-pharyngeal apparatus of the Macrobiotus - type ( Fig. 2 ). Mouth antero-ventral, surrounded by a ring of 10 peribuccal lamellae. Oral cavity armature of the harmsworthi - type, with three well developed bands of teeth. Teeth of the first band are smaller than those of the other two bands and are visible in PCM as granules. They are present in the anterior portion of the oral cavity just behind the peribuccal lamellae. This band of teeth is continuous and looks the same on all oral cavity walls. Teeth in the second band are intermediate in size between those of the first band and those of the third band of teeth. They are in the shape of small granules and ridges parallel to the main axis of the buccal tube. They are positioned in the posterior portion of the oral cavity just behind the ring fold and just before the third band of teeth. This band is continuous and teeth are arranged in one row. Teeth of the third band are larger than those in the other two bands. They are in the shape of transverse ridges/baffles or granules (PCM). They are positioned in the rear of the oral cavity just behind the second band of teeth and just before the buccal tube opening. Usually this band is not continuous and is divided into two series: ventral and dorsal. Both series consist of one median and two lateral teeth. The medio-ventral tooth may be broken into two (or more) smaller teeth, thus there may be seven (or more) teeth in this band.

Buccal tube is strengthened with the ventral lamina and one bend in anterior part of tube (visible in lateral view). Pharyngeal bulb slightly oval, with apophyses, three macroplacoids and a microplacoid. Pharyngeal apophyses distinct, rounded and forked posteriorly. First macroplacoid rod-shaped and thinner anteriorly, second round or oval, and third rod-shaped with a subterminal constriction. Second macroplacoid placed slightly closer to the first than to the third macroplacoid. Macroplacoid length sequence (from smallest to largest): 2-3-1. Microplacoid small, thin and placed close to the third macroplacoid.

Claws of the hufelandi - type, stout ( Fig. 3 ). Primary branches with distinct accessory points. Lunules on all legs smooth. Thin bars under claws I–III present. Other cuticular thickenings on legs absent.

Egg (measurements in Table 2 ): White/transparent, laid freely ( Figs 4–8 ). Spherical, without areolation. Processes in the shape of long, smooth flexible spines, with very wide bases (or, in other words, very short cones with extremely long and flexible spines) ( Figs 7–8 ). Processes composed of two walls (internal and external). The two walls are supported by a system of partitions. Under PMC these partitions are visible as a reticular design for most species of the harmsworthi group, however, in M. binieki sp. nov. the partitions are thick and as a consequence seen as small bubbles rather than a mesh ( Fig. 5 ). At the process base there is a crown of rectangular swellings (which could also be interpret as very small finger-like structures) ( Figs 5–6 ). Processes are distributed on the surface of the egg very close one to another (occasionally in contact). Surface between processes is covered by an irregular pattern (wrinkles) visible in PCM as darker and lighter areas ( Figs 5–6 ).

Type depositories. Holotype and 16 paratypes (12 adults and 4 eggs) are preserved at the Department of Animal Taxonomy and Ecology, A. Mickiewicz University, Poznań.

Etymology. The new species is named after Janusz Biniek, a mentor of contract bridge players in the city of Poznań, on the occasion of his 84th birthday.

Differential diagnosis. M. binieki sp. nov. is most similar, in regard to the non-areolated egg shell and a crown of thickenings around egg processes, to M. australis Pilato & D'Urso, 1976 , M. patiens Pilato, et al., 2000 , M. pseudocoronatus Pilato et al., 2006 , M. rigidus Pilato & Lisi, 2006 and M. simulans Pilato et al., 2000 . The new species differs specifically from:

M. australis by: a different type of the oral cavity armature ( harmsworthi - type in the new species and the echinogenitus - type in M. australis ), a lower pt of stylet supports (74.9–77.8 in the new species and ca. 83.7 in M. australis ), the egg surface covered by wrinkles (dots in M. australis ), the process walls with small bubbles (smooth in M. australis ), a higher process height/base width ratio (1.51–1.61 in the new species and 0.95–1.05 in M. australis ), a higher number of processes on the egg circumference (27–32 in the new species and 19–20 in M. australis ), a larger diameter of eggs without processes (85.1–94.5 in the new species and around 76.0 in M. australis ) and with processes (108.7–114.7 in the new species and around 96.0 in M. australis ), narrower bases of egg processes (6.5– 9.0 in the new species and ca. 10.5 in M. australis ).

M. coronatus by: a different type of the oral cavity armature ( harmsworthi - type in the new species and the areolatus - type in M. coronatus ), the egg surface covered by wrinkles (dots in M. coronatus ), the process walls with small bubbles (reticulated in M. coronatus ), a higher process height/base width ratio (1.51–1.61 in the new species and 0.88–0.96 in M. coronatus ), a higher number of processes on the egg circumference (27–32 in the new species and 11–18 in M. coronatus ), a larger diameter of eggs without processes (85.1–94.5 in the new species and around 47.0–55.0 in M. coronatus ) and with processes (108.7–114.7 in the new species and around 61.0–71.0 in M. coronatus )

M. patiens by: the presence of eyes, a larger body size (359–647 in the new species and 240–350 in M. patiens ), a lower pt of the buccal tube external width (12.0– 13.2 in the new species and 17.9–21.1 in M. patiens ), a lower pt of the second macroplacoid length (7.6–8.9 in the new species and 11.9–13.8 in M. patiens ), a lower pt of the microplacoid length (5.5–7.4 in the new species and 10.4–12.9 in M. patiens ), a lower pt of the macroplacoid row length (34.4–40.8 in the new species and 42.7–48.9 in M. patiens ), a lower pt of the placoid row length (42.3– 49.6 in the new species and 55.1–62.5 in M. patiens ), the egg surface covered by wrinkles (dots in M. patiens ), the process walls with small bubbles (reticulated in M. patiens ), a higher process height/base width ratio (1.51–1.61 in the new species and ca. 0.65–1.05 in M. patiens ), a higher number of processes on the egg circumference (27–32 in the new species and 10–16 (usually 12) in M. patiens ), a larger diameter of eggs with processes (108.7–114.7 in the new species and 90.5–100.0 in M. patiens ), narrower bases of egg processes (6.5–9.0 in the new species and 12.4– 19.0 in M. patiens ).

M. pseudocoronatus by: having smooth cuticle (small dorsal and lateral tubercles present in M. pseudocoronatus ), the absence of teeth on lunules IV, a lower pt of the buccal tube external width (12.0– 13.2 in the new species and 17.5–18.4 in M. pseudocoronatus ), a lower pt of the second macroplacoid length (7.6–8.9 in the new species and 11.7–13.6 in M. pseudocoronatus ), a lower pt of the third macroplacoid length (10.2–12.5 in the new species and 15.0– 18.4 in M. pseudocoronatus ), a lower pt of the microplacoid length (5.5–7.4 in the new species and 11.4– 11 .5 in M. pseudocoronatus ), a lower pt of the macroplacoid row length (34.4–40.8 in the new species and 47.3– 52.4 in M. pseudocoronatus ), a lower pt of the placoid row length (42.3–49.6 in the new species and 60.0– 65.1 in M. pseudocoronatus ), the egg surface covered by wrinkles (dots in M. pseudocoronatus ), the walls of processes with small bubbles (reticulated in M. pseudocoronatus ), a higher process height/base width ratio (1.51–1.61 in the new species and ca. 0.91–0.95 in M. pseudocoronatus ), a higher number of processes on the egg circumference (27–32 in the new species and 14 in M. pseudocoronatus ), a larger diameter of eggs without processes (85.1–94.5 in the new species and around 50.1 in M. pseudocoronatus ) and with processes (108.7–114.7 in the new species and ca. 82.3 in M. pseudocoronatus ), narrower bases of egg processes (6.5–9.0 in the new species and 11.5–13.9 in M. pseudocoronatus ).

M. radiatus by: the presence of eyes, a lower pt of the buccal tube external width (12.0– 13.2 in the new species and 17.5–20.1 in M. radiatus ), a lower pt of the second macroplacoid length (7.6–8.9 in the new species and 13.5– 14.2 in M. radiatus ), a lower pt of the third macroplacoid length (10.2–12.5 in the new species and 13.8–17.6 in M. radiatus ), a lower pt of the microplacoid length (5.5–7.4 in the new species and 10.9–11.3 in M. radiatus ), a lower pt of the macroplacoid row length (34.4–40.8 in the new species and 46.1–51.4 in M. radiatus ), a lower pt of the placoid row length (42.3–49.6 in the new species and 58.5–64.1 in M. radiatus ), the egg surface covered by wrinkles (stripes forming a large radiate crown in M. radiatus ), the process walls with small bubbles (reticulated in M. radiatus ), a higher number of processes on the egg circumference (27–32 in the new species and ca. 11 in M. radiatus )

M. rigidus by: a different type of the oral cavity armature ( harmsworthi - type in the new species and the areolatus - type in M. rigidus ), the presence of eyes, the absence of teeth on lunules on IV, a lower pt of the buccal tube external width (12.0– 13.2 in the new species and 17.5–20.1 in M. rigidus ), a lower pt of the second macroplacoid length (7.6–8.9 in the new species and 13.5–14.2 in M. rigidus ), a lower pt of the third macroplacoid length (10.2– 12.5 in the new species and 13.8–17.6 in M. rigidus ), a lower pt of the microplacoid length (5.5–7.4 in the new species and 10.9–11.3 in M. rigidus ), a lower pt of the macroplacoid row length (34.4–40.8 in the new species and 46.1–51.4 in M. rigidus ), a lower pt of the placoid row length (42.3–49.6 in the new species and 58.5–64.1 in M. rigidus ), the egg surface covered by wrinkles (dots in M. rigidus ), the walls of processes with small bubbles (reticulated in M. rigidus ), a higher process height/base width ratio (1.51–1.61 in the new species and ca. 1.05 in M. rigidus ), a higher number of processes on the egg circumference (27–32 in the new species and 12 in M. rigidus ), a larger diameter of eggs without processes (85.1–94.5 in the new species and ca. 64.0 in M. rigidus ) and with processes (108.7–114.7 in the new species and around 91.0 in M. rigidus ), narrower bases of egg processes (6.5–9.0 in the new species and 14.5–15.2 in M. rigidus ).

M. simulans by: the absence of teeth on lunules IV, a larger body size (359–647 in the new species and 280– 360 in M. simulans ), a lower pt of the buccal tube external width (12.0– 13.2 in the new species and 17.6–21.1 in M. simulans ), a lower pt of the second macroplacoid length (7.6–8.9 in the new species and 11.2–12.8 in M. simulans ), a lower pt of the microplacoid length (5.5–7.4 in the new species and 9.6–11.7 in M. simulans ), a lower pt of the placoid row length (42.3–49.6 in the new species and 52.4–59.2 in M. simulans ), the egg surface covered by wrinkles (dots in M. simulans ), the walls of processes with small bubbles (reticulated in M. simulans ), a higher process height/base width ratio (1.51–1.61 in the new species and around 0.69–1.00 in M. simulans ), a higher number of processes on the egg circumference (27–32 in the new species and 11–13 in M. simulans ), a larger diameter of eggs without processes (85.1–94.5 in the new species and 43.0–82.0 in M. simulans ) and with processes (108.7–114.7 in the new species and 59.0–99.0 in M. simulans ), narrower bases of egg processes (6.5–9.0 in new species and 11.0– 16.0 in M. simulans ).

Figures

FIGURES 1 – 3. Macrobiotus binieki sp. nov. adult: 1. habitus (ventral view, holotype), 2. buccal apparatus (ventral view, holotype), 3. claws III.

FIGURES 4 – 8. Macrobiotus binieki sp. nov. egg: 4. mid-section, 5 – 6. egg surface (at two different focusing levels), 7 – 8. processes. Scale on 6 same as on 5 and scale on 8 same as on 7.

Tables

TABLE 2. Measurements [in µm] of selected morphological structures of eggs of Macrobiotus binieki sp. nov. mounted in Hoyer’s medium (RANGE refers to the smallest and the largest structure found among all measured eggs / structures; N—number of eggs / structures measured, SD—standard deviation).

CHARACTER N	MIN	MAX	MEAN	SD
Diameter of egg without processes 3	85.1	94.5	89.6	4.7
Diameter of egg with processes 3	108.7	114.7	112.2	3.1
Processes height 12	9.8	14.5	12.3	1.4
Processes base width 12	6.5	9.0	7.7	0.8
Process base/height ratio 12	0.50	0.79	0.63	0.09
Distance between processes 12	1.9	3.1	2.6	0.4
Number of processes on egg the circumference 3	27	32	29.3	2.5