Macrobiotidae Thulin, 1928

Vecchi, Matteo, Stec, Daniel, Calhim, Tommi Vuori Sara, Ryndov, Serge & Chartrain, Justine, 2022, Garypus sanasai Lin, Huang & Chang 2022, sp. nov., Zoological Studies (Zool. Stud.) 61 (22), pp. 1-15 : 6-7

Family: Macrobiotidae Thulin, 1928 Genus: Macrobiotus Schultze C.A.S., 1834

Macrobiotus naginae sp. nov. Vecchi, Stec, Vuori, Ryndov, Chartrain and Calhim ( Figs. 2–6 ; Tables 4–5; Table S1) urn:lsid:zoobank.org:act:53E10ACB-6DAA-4E63-B263-5919B00FDF3C

Material examined: 47 animals and 10 eggs. Specimens mounted on microscope slides in Hoyer’s medium (34 animals + 7 eggs), fixed on SEM stubs (11 + 3), and processed for DNA sequencing (2+0).

Type locality: 64°34'36.4"N 26°29'46.1"E; 37 m a.s.l.; Rokua National Park, Utajärvi, Finland; moss on sand; coll. 25th of May 2020 by Matteo Vecchi, Sara Calhim, Justine Chartrain and Serge Ryndov.

Type repository: Holotype (S226.SL1.F with 5 paratypes), 74 paratypes (slides S227.SL1, S228.SL1, S232.SL1, S233.SL1, S235.SL1, S245.SL1, S246.SL1, S247.SL1, S248.SL1, S249.SL1; SEM stubs S226- 1t) and 12 eggs (slides S226.SL.2–3, S227.SL.2–4; SEM stub S226-e1) are deposited at the Department of Biological and Environmental Sciences , University of Jyväskylä (Survontie 9C, 40500, Jyväskylä, Finland).

Etymology: Named after J. K. Rowling’s Harry Potter book series character Nagini – Lord Voldemort’s treasured snake companion. Formerly a cursed woman who is ultimately and irreversibly transformed into a limbless beast, this fictional character provides a fitting name for the new species in the pseudohufelandi complex, which in turn is characterized by reduced legs and claws.

Species description: Animals (measurements and statistics in Table 4): In live animals, body opaque whitish; transparent after fixation in Hoyer’s medium ( Fig. 2A ). Eyes present in live animals and after fixation in Hoyer’s medium. Cuticular pores weakly visible in PCM, and very visible in SEM ( Figs. 2B–C , 3A–B ) present on the dorsal surface of body and legs. Under PCM no granulation visible on legs. Few pores present on legs ( Fig. 3A–B ). Garter-like structure (as defined by Massa et al. 2021) covered with microgranulation present on all legs ( Fig. 3 ). Claws reduced, Y-shaped, of the Xerobiotus type ( Pilato and Binda 2010) without lunulae or cuticular thickenings at the base ( Fig. 4 ). Cuticular bars associated with claws I–III absent.

Mouth anteroventral. Buccopharyngeal apparatus of the Macrobiotus type ( Fig. 5A ), with ventral lamina and ten small peribuccal lamellae. Pharyngeal bulb spherical, with triangular apophyses, three anterior cuticular spikes (typically only two are visible in any given plane; Fig. 5C ), two rod-shaped macroplacoids and a drop-shaped microplacoid ( Fig. 5A ). The macroplacoid length sequence is 2 <1. The first and the second macroplacoid have a weak central and subterminal constriction, respectively ( Fig. 5B–C ).

Under PCM, the oral cavity armature is of the maculatus type, i.e., with only the third band of teeth visible ( Fig. 5D–G ). The third band of teeth is divided into a dorsal and ventral portion. Under PCM, the dorsal teeth are composed of three distinct transverse ridges ( Fig. 5D–E ). The ventral teeth appear as two separate lateral transverse ridges between which one or two small medial teeth (roundish in PCM) are visible ( Fig. 5F–G ).

Eggs (measurements and statistics in Table 5): Eggs round, whitish and laid freely in the environment ( Fig. 6A, B and G ). The surface between processes is of the hufelandi type, i.e., covered with a reticulum ( Fig. 6E–F ). The meshes of the reticulum are uniform in size and evenly distributed on the egg surface between the processes. Bars and nodes of the reticulum are usually thicker/wider than the meshes diameter that ranges from about 0.15 to 0.30 µm. The pillars connecting the reticulum with the chorion surface are visible only in SEM. Thickening surrounding process bases are poorly marked/visible and merge gently into the bars and nodes of the reticulum. An internal septum between the process trunk and the terminal disc is visible in PCM ( Fig. 6C ). Processes are of the hufelandi type with a concave trunk and a relatively small and concave terminal disc. The terminal disk is greatly indented on the disk margin, creating evident teeth that have thickened and rounded tips and resemble short, nodular, finger-like apices ( Fig. 5C–D ). Sometimes these nodular finger-like apices are also present in the central area of the terminal disk, giving the disk a convex impression. Under SEM, the surface nodular apices/teeth in terminal discs are covered by microgranules ( Fig. 6D and F ).

Reproduction: The species is dioecious. Sperm with corkscrew shaped nucleus ( Fig. 6H ). Spermathecae present in females ( Fig. 6I ).

DNA sequences

DNA sequences of four markers were obtained for two individuals. Their GenBank accession numbers are: 18S: OK663219, OK663220.

28S: OK663230, OK663231.

COI: OK662990, OK662991.

ITS2: OK663208, OK663209.

Figures

Fig. 2. Macrobiotus naginae sp. nov. – habitus and cuticular pores: A, dorsoventral view of the body (Holotype; Hoyer’s medium, PCM); B–C, cuticular pores on the dorsal part of the body under PCM (B) and under SEM (C). Flat arrowheads indicate pores on the dorsocaudal cuticle. Scale bars: A = 100 mm; B–C = 10 mm.

Fig. 3. Macrobiotus naginae sp. nov. – cuticular structures on legs: A, garter-like structure on leg II under PCM; B, garter-like structure on leg III under PCM; C, garter-like structures and claws III under SEM. Flat arrowheads indicate pores on the leg cuticle, flat empty arrowheads indicate garter-like structures. Scale bars: A–B = 20 μm; C = 10 μm.

Fig. 4. Macrobiotus naginae sp. nov. – claws: A–B, claws I and IV, respectively, under PCM; C, claws IV under SEM. Flat arrowhead indicates an abnormal additional spur on the base on anterior claw IV; flat empty arrowheads indicate accessory points on primary branches. Scale bars = 10 μm.

Fig. 5. Macrobiotus naginae sp. nov. – buccal apparatus and the oral cavity armature under PCM: A, dorsoventral view of the entire buccal apparatus; B–C, placoid morphology in ventral (B) and dorsal (C) view, respectively. D–G, oral cavity armature in dorsal (D–E) and ventral (F–G) view, respectively. Flat arrowhead indicates weak constrictions in the macroplacoids, flat empty arrowheads indicate third band of the Oral Cavity Armature (OCA), arrow indicates cuticular spikes between end of the buccal tube and anterior portion of the pharynx. Scale bars: A = 20 μm; B–G = 10 μm.

Fig. 6. Macrobiotus naginae sp. nov. – egg chorion morphology and reproduction:A–B, egg surface under PCM; C, egg process under PCM; D, egg process under SEM; E, chorion surface between processes under PCM; F, chorion surface between processes under SEM; G, in toto egg under SEM; H, orcein-stained sperm inside male gonad under PCM; H, orcein-stained sperm inside female spermatheca under PCM. Flat arrowhead indicates the septum between process trunk and terminal disk: flat empty arrowhead indicates thickenings surrounding the processes; arrows indicate sperm nuclei. Scale bars: A–B, G–I = 10 μm; C–F = 2 μm.