Macrobiotus noemiae, Roszkowska & B, 2019

Roszkowska, Milena & B, Łukasz Kaczmarek, 2019, Macrobiotus noemiae sp. nov., a new tardigrade species (Macrobiotidae: hufelandi group) from Spain, Turkish Journal of Zoology 43 (4), pp. 331-348 : 332-336

Macrobiotus noemiae sp. nov., Tables 1 and 2, Figures 1–10

Macrobiotus recens Cuénot, 1932 ( Guil, 2002), probably also Macrobiotus recens (in Guil et al., 2009, Guil and Sanchez-Moreno, 2013)

Type material examined: 12 animals, 3 eggs (one with embryo) (holotype and 14 paratypes) on microscope slides in Faure’s medium.

Additional material: 41°00′56.3″N, 3°39′0.6″W, 1040 m a.s.l., Spain, 0.5 km from Gascones, road M-636, next to the pond, moss from rock, date 25 Oct. 2001 (2 eggs) ; 41°03′59.3″N, 3°31′9.6″W, 1160 m a.s.l., Spain, on the Montejo city limit to La Hiruela, road M-137, leaf litter, date 25 Oct. 2001 (1 specimen and 7 eggs) ; 40°50′22.1″N, 3°57′16.8″W, 2020 m a.s.l., Spain, Parque Regional de Peñalara , moss from rock, date 27 May 2001 (1 specimen and 3 eggs) ; 41°06′34.3″N, 3°35′49.6″W, 1280 m a.s.l., Spain, old road N-I, Dehesa Boyal, Robregordo, leaf litter, date 25 Oct. 2001 (1 egg) .

3.1.1. Description of the new species

Animals (measurements and statistics in Table 1): Body transparent after fixation in Faure’s medium, eyes present in 33% of fixed specimens ( Figure 1 ). Entire cuticle covered with conspicuous small, round pores (0.8–1.1 µm in diameter) distributed randomly. Easily visible granulation present on legs I–IV ( Figure 5 ). Buccopharyngeal apparatus of the Macrobiotus type, with ventral lamina and ten peribuccal lamellae ( Figures 1 and 2 ). Mouth anteroventral. Oral cavity armature of the patagonicus type, with only second and third bands of teeth visible under light microscope (LM) ( Figures 3a and 3b ). The second band of teeth is composed of small granules arranged in several rows, just above the third band of teeth ( Figures 3a and 3b , arrow). The third band of teeth is composed of three dorsal and three ventral teeth, which appear under LM in the shape of transverse ridges ( Figures 3a and 3b , indented arrowhead). Pharyngeal bulb spherical with triangular apophyses, two rodshaped macroplacoids, and a triangular microplacoid. Macroplacoid length configuration 2 <1 ( Figure 2 ). The first macroplacoid possesses a central constriction ( Figure 2 , empty arrowhead). The second macroplacoid with subterminal constriction ( Figure 2 , filled arrowhead). Claws of the hufelandi type, stout ( Figures 4 and 6 ). Primary branches with distinct accessory points. Lunules on claws I–III smooth, on claws IV dentate. Thin paired cuticular bars under claws I–III present ( Figure 5 , arrow). Other cuticular thickenings on legs absent.

Eggs (measurements and statistics in Table 2): Eggs spherical, ornamented, and laid freely ( Figures 7–10 ), with a chorion surface of the hufelandi type with reticulated surface, sometimes hardly visible ( Figures 8 and 9 ). All processes situated close to one another, sometimes in contact ( Figures 8 and 9 ). Processes in the shape of cones with blunt apex, but the apex sometimes divided on the top ( Figure 8 , arrow). Terminal disc absent or not detectable under PCM. In the apical part of the processes few (2–5) long, thin, hair-like, and flexible filaments present (Figure mounted in Faure’s medium (N – number of specimens/structures measured, Range – smallest and largest structures among all measured eggs; SD – standard deviation).

ROSZKOWSKA and KACZMAREK / Turk J Zool

10, arrowheads).

Etymology: We dedicate this species to Noemi Guil López, a Spanish tardigradologist who collected the species and prepared the microscope slides that we examined.

Type locality: 40°51′29.1″N, 3°50′40.4″W, 1640 m a.s.l., Spain, Puerto de la Morcuera , road M-611, leaf litter from meadow, date 16 May 2001, sample collector: Noemi Guil López.

Type depositories: Holotype and 11 paratypes (slide: 23.01/142), three eggs (slide: 23.01/2301), and additional material are deposited at the Museo Nacional de Ciencias Naturales in Madrid, Calle de José Gutiérrez Abascal, 2, 28006 Madrid, Spain.

Differential diagnosis: Based on morphology of egg processes, the new species is most similar to M. naskreckii and M. recens , but differs specifically from:

1. Mac. naskreckii , known only from its type locality in Mozambique (Bąkowski et al., 2016), by: presence of an oral cavity armature of the patagonicus type (maculatus type in M. naskreckii ); second macroplacoid with subterminal constriction; higher pt of stylet support insertion point (78.3–81.8 in M. noemiae sp. nov. vs. 74.1–77.8 in M. naskreckii ); lower pt of ventral lamina length (48.4–55.7 in M. noemiae sp. nov. vs. 57.7–63.1 in M. naskreckii ); egg chorion with visible reticulation under LM (smooth in M. naskreckii ); lack of terminal disc on the top of egg processes; presence of long, thin, hair-like, and flexible filaments on the top of processes; higher number of processes on the egg circumference (35–36 in M. noemiae sp. nov. vs. 27–32 in M. naskreckii ); and larger egg bare and full diameter (100.6–105.7 µm and 118.5–123.5 µm respectively in M. noemiae sp. nov. vs. 55.9–76.0 µm and 72.0–92.0 µm respectively in M. naskreckii ).

2. Mac. recens , known from many localities, mainly in Europe ( McInnes, 1994), by: egg chorion with visible reticulation under LM (slightly granulated in M. recens ); presence of long, thin, hair-like, and flexible filaments on the top of processes; smaller egg full diameter (118.5– 123.5 µm in M. noemiae sp. nov. vs. 130.0–160.0 µm in M. recens ); shorter processes (7.4–9.1 µm in M. noemiae sp. nov. vs. ca. 15.0 µm in M. recens ).

3.2. Remarks on the tardigrade collection from MNCN As part of the SYNTHESYS Project, 381 slides containing species identified as Macrobiotus areolatus (now Paramacrobiotus areolatus ( Murray, 1907)) , Mac. harmsworthi (now Mesobiotus harmsworthi ( Murray, 1907)) , Mac. recens , Mac. richtersi (now Paramacrobiotus richtersi ( Murray, 1911)) , Milnesium eurystomum Maucci, 1991 , Mil. tardigradum Doyère, 1840 , Mil. tetralamellatum Pilato & Binda, 1991 , and Milnesium sp. were verified in order to provide their correct identification (see Table 3). Specimens identified previously as Mac. recens were attributed to a species new for science described in this paper. Examination of slides revealed this species also in other samples, which may indicate a wider distribution of this species in Spain. The taxonomic status of Mac. recens is still unclear and detailed redescription of this species is necessary (for more details see Pilato and Bertolani, 2004; Stec et al., 2018). It was not possible to identify to the species level most of the individuals attributed previously to Mac. harmsworthi and Mac. areolatus because in most cases eggs were absent on examined slides. Only in one case were eggs attributed to Mac. harmsworthi found to belong to the newly described species – Mac. noemiae sp. nov. A similar situation was seen in the context of specimens marked as the species Mac. richtersi , where in many samples eggs were not found. When the eggs were present, Mac. richtersi specimens were attributed to Pam. sklodowskae Michalczyk, Kaczmarek & Węglarska, 2006 or Pam. cf. sklodowskae , if eggs were damaged and not all structures were visible or if some measurements differed in some eggs or individuals, while morphologically they were identical with original species description. Milnesium tardigradum was not confirmed on any of examined slides. Specimens with claw configuration [3–3]–[3–3] were attributed mainly to Mil. dornensis Ciobanu, Roszkowska & Kaczmarek, 2015 or Mil. cf. dornensis (if some measurements were different in comparison to the original description), whereas those with claw configuration [2–3]–[3–2] also had clearly visible pseudopores on the cuticle and were attributed to Mil. beasleyi Kaczmarek, Jakubowska & Michalczyk, 2012 . We decided to classify several individuals as Mil. cf. beatae because of some differences in measurements in comparison to the original description as well as the fact that Mil. beatae Roszkowska, Ostrowska & Kaczmarek, 2015 has so far been reported only from Argentina (type locality) and the United States (Roszkowska et al., 2015; Tibbs et al., 2016). Milnesium berladnicorum Ciobanu, Zawierucha, Moglan & Kaczmarek, 2014 was reported only on one slide, but

Figures

Figures 1–3a. Macrobiotus noemiae sp. nov.: 1- dorsoventral assembled image (holotype); 2- buccopharyngeal apparatus (dorsoventral assembled image), the empty arrowhead indicates the first macroplacoid with central constriction, the filled arrowhead indicates the second macroplacoid with a sub-terminal constriction (holotype); 3a- oral cavity armature, the arrow indicates teeth of the second band, the indented arrowhead indicates teeth of the third band (holotype). Scale bars in micrometers. All PCM.

Figures 4–6. Macrobiotus noemiae sp. nov.: 4- claws II with smooth lunules (holotype); 5- granulation on leg II (paratype); 6- claws IV with dentate lunules (holotype). Scale bars in micrometres. All PCM.

Figures 7–10. Macrobiotus noemiae sp. nov. – eggs: 7- general view; 8–9- egg surface and processes, arrow indicates process with divided apical part; 10- long, hair-like, and flexible filaments present on the apical part of processes (arrowheads). Scale bars in micrometres. All PCM.