Echiniscus gemmatus Leong, Yu, Tsai, Kaczmarek, Lee & Lin, 2024, sp. nov.
Creators: name: Leong, Weng-I
name: Yu, Jr-Kai
name: Tsai, Isheng Jason
name: Kaczmarek, Łukasz
name: Lee, Yi-Chien
name: Lin, Chung-Ping
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Tardigrada
Heterotardigrada
Echiniscoidea
Echiniscidae
Echiniscus
Echiniscus gemmatus

description: Echiniscus gemmatus sp. nov. Leong, 2024
urn:lsid:zoobank.org:pub: 16C22BBD-C3D0-4D72-BF1D-2BD2F04BD118
(Figures 1–5, Tables 5–7)
Type material: Holotype (female on slide M.0701), 16 paratypes (slides M.0702–17 with 15 females, 1 juvenile) mounted on microscope slides in Hoyer’s medium and three paratypes fixed on a SEM stub (No. 0723). Holotype, 8 paratypes (slides M.0702–09) and three paratypes fixed on a SEM stub (No. 0723) were deposited in the National Museum of Natural Science, Taichung, Taiwan and 8 paratypes (slides M.0710–17) were deposited in Department of Animal Taxonomy and Ecology, Faculty of Biology, Adam Mickiewicz University in Poznań, Poland.
Description
Adult females (measurements and statistics in Table 5). Before mounting, the body appears orange and plump (Fig. 2B), with red eyes. Bulbous cirrophores present at the base of the cirrus (Fig. 1A–B). Dactyloid/ovoid cephalic papillae (secondary clavae) and minute (primary) clavae present (Figs 1A, C, 2B). Cirrus A short (cirrus A /body length ratio 11–17%). The trunk appendage configuration is A-(B)-C-(Cd)-(Dd)-E (Fig. 1A, white arrowheads). Appendages exhibit significant variability in terms of asymmetries and lengths (see Table 6). In general, all appendages are smooth (Fig. 4A–E). Asymmetry in the development of appendages often happens, where one of the spines B and C is sometimes missing, and occasionally, one of the Cd is absent too; specifically, the absence of one of spine B was observed in 33.3% of the specimens assessed (2 out of 6), while one of spine C was absent in 50% of the specimens examined (3 out of 6). Additionally, the absence of one of spines Cd was noted in 28.6% of the specimens evaluated (2 out of 7). Assessment was based on specimens visible on photographs, as some were positioned laterally, obscuring the spines. Appendages C and Cd are short spines of similar length, while appendage B is a spicule. Dorsal spines Dd and E are also short spines (Figs 1A–B, 4A–E). Gonopore is a rosette-shaped (Fig. 1C, empty indented arrowheads). Dorsal plates of the new species have a spinulosus sculpture type, which means they have irregularly distributed pores in all plates. However, the pores of anterior portion of first and second paired plate often gradually become small or even not visible. Most of pores on the dorsal plate have a diameter ranging from 0.3 to 0.6 μm, some larger are visible under PCM as bright dots (Figs 1A, 2A) and under DIC as light hollows (Figs 1B, 2B). Dark central rings in pores are absent (Figs. 1A–B, 2A–B). The density of pores is ca. 7–12 pores per 100 μm ² in the majority of specimens (see Table 7). Additionally, the ventral sculpture is visible as tiny granulation (Fig. 1C).
The cephalic plate is narrow and with an anterior incision (Fig. 1A–B). The cervical (neck) plate is narrow and formed as a thin dark belt without pores (Figs 1A, 2A). A smooth, thin transverse stripe divides the first and second paired plates into smaller, narrower anterior and larger posterior parts (Figs 1A–B, 2A–B). Median plates I and III are unipartite, whereas median plate II is divided into a narrower anterior and a wider posterior part (Fig. 1A–B). Median plate III is tiny, but densely arranged pores, often partially covered under the paired plate II and the caudal plate (Figs 1A–B, 2A–B). The caudal plate with well visible incisions (Figs 1A–B, 2A–B). Pedal plates I–III are extremely weakly developed, but visible under PCM (Fig. 2A, filled indented arrowheads), whereas IV is well developed (Figs 1A–B, 2A–B, 3E). There are small pulvini present on legs (Fig. 2A, black arrowheads). The first pair of legs have a small spine, and there is a papilla present on the fourth pair of legs (Figs 2A–B, 3E, empty indented arrowheads). The fourth pair of legs also has a dentate collar with many large teeth, ranging from 9 to 15 teeth (Figs 1A, 3E). It should be noted that there is possible high variability between the two collars in the same specimen. Claws I–IV are of similar length, and the external most and internal most claws on all legs are smooth. The internal claws have small, slender spurs located close to the claw bases (Figs 1A, C, 3A–E).
Juvenile morphology is similar to that of adult females, including appendage configuration and sculpturing (Fig. 5). These features are representative of the juvenile stage, which has distinct morphological traits. Pores on dorsal plates are well visible (Fig. 5). Body length is 141 µm. The scapular plate length is 29.2 µm. Head appendage lengths: cirrus internus is 7.8 µm, cephalic papilla is 2.2 µm, cirrus A is 19.6 µm, and cirrus A /Body length ratio is 14%. Body appendages lengths: cirrus B is 1.4 µm, cirrus Cd is 3.9 µm, cirrus Dd is 7.8 µm, cirrus E is 4.4 µm, spine on leg I length is 1.7 µm. The notch length is 13.5 µm. Claw lengths (I: 6.8 µm, II: 6.7 µm, III: 7.5 µm and IV: 10.2 µm). Gonopore absent.
No eggs, males, and larvae were found.
Etymology
The “ gemmatus ” comes from Latin and means “bejeweled,” referring to the resemblance of the new species to a precious orange carnelian stone.
description: Published as part of Leong, Weng-I, Yu, Jr-Kai, Tsai, Isheng Jason, Kaczmarek, Łukasz, Lee, Yi-Chien & Lin, Chung-Ping, 2024, Echiniscus gemmatus sp. nov. (Heterotardigrada: Echiniscidae; the spinulosus morphogroup) from Macau, China, pp. 333-352 in Zootaxa 5551 (2) on pages 338-343, DOI: 10.11646/zootaxa.5551.2.5, http://zenodo.org/record/14421272