Mesobiotus dilimanensis, Itang & Stec & Mapalo & Mirano-Bascos & Michalczyk, 2020

Itang, Lowelyn A. M., Stec, Daniel, Mapalo, Marc A., Mirano-Bascos, Denise & Michalczyk, Łukasz, 2020, An integrative description of Mesobiotus dilimanensis, a new tardigrade species from the Philippines (Eutardigrada: Macrobiotidae: furciger group), Raffles Bulletin of Zoology 68, pp. 19-31 : 21

Mesobiotus dilimanensis , new species

( Tables 3, 4, Figs. 1–5 )

Material examined: 65 animals (including eight simplex), 47 eggs, and 7 empty chorions mounted on microscope slides in Hoyer’s medium, 5 eggs fixed on SEM stubs, and 8 specimens processed for DNA sequencing.

Type locality: 14°39′40″N, 121°04′07″E; 76 m asl: Philippines, Quezon City, Diliman, University of the Philippines, A. Roces St. ; moss on a rock; September 2015; coll. Lowelyn Itang.

Etymology: The species is named after Diliman, the district in Quezon City, Philippines, where it was discovered.

Type depositories: Holotype: slide PH.006.10 with six paratypes; 58 paratypes (slides: PH.006. *, where the asterisk can be substituted by any of the following numbers: 02–03, 11–16), 47 eggs (slides: PH.006. *: 5–9, 17); seven empty chorions (slides: PH.006. *: 01, 04) are deposited at the Institute of Zoology and Biomedical Research , Jagiellonian University , Gronostajowa 9, 30-387, Kraków, Poland.

Figures

Fig. 1. Mesobiotus dilimanensis, new species, PCM image of habitus and leg’s cuticle morphology. A, dorso-ventral projection (holotype); B, granulation on the external surface of leg III (paratype); C, granulation on dorsal surface of leg IV (paratype); D, pulvinus on the internal surface of leg II (paratype). Filled indented arrowheads indicate the granulation on the legs, empty indented arrowhead indicates the pulvinus, the filled flat arrowhead indicates the cuticular bar under the claws and the empty flat arrowhead indicated muscle attachment. Scale bar in μm.

Fig. 2. Mesobiotus dilimanensis, new species, PCM images of claws. A, claws III with smooth lunules (holotype); B, claws IV with smooth lunules (paratype). Filled indented arrowheads indicate claws’ septa, filled arrowhead indicates the cuticular bar, the empty arrowhead indicates paired muscles attachments and arrow indicates horseshoe structure connecting the anterior and the posterior claw. Scale bars in μm.

Fig. 3. Mesobiotus dilimanensis, new species, PCM images of the buccal apparatus. A, an entire buccal apparatus (paratype); B, C, the oral cavity armature of the paratype, dorsal and ventral teeth respectively; D, the oral cavity armature of another paratype, ventral teeth; E, F, placoid morphology of the paratype, dorsal and ventral placoids respectively. Arrowheads indicate subterminal constrictions in the third macroplacoid. Scale bars in μm.

Fig. 4. Mesobiotus dilimanensis, new species, images of the eggs under light microscopy. A, midsection (PCM); B, surface (PCM); C, D, surfaces under a ×1000 magnification (PCM and NCM, respectively); E–J, midsections of six different egg processes (PCM). Flat arrowheads indicate faint thickenings around the processes’ bases, indented arrowheads indicate small tubercles on the surface of the egg processes. Scale bars in μm.

Fig. 5. Mesobiotus dilimanensis, new species, images of eggs under SEM. A, entire view of the egg; B, C, details of the egg surface between processes; D, egg processes; E, F, a top part of the processes divided into several short nodular branches. Flat arrowheads indicate faint thickenings around the processes’ bases, indented arrowheads indicate small tubercles on the surface of the egg processes. Scale bars in μm.