Minibiotus gumersindoi n. sp. Diagnosis Cuticle with transversal bands of large and round pores, a very large round pore close to the end of each leg; granulation on legs not visible; three round macroplacoids of the same size and a solid and distinct microplacoid; slender claws with short but evident accessory points and smooth lunules. Description Body length 162.0 m (Tables 1–2), colourless. Eyes not visible, probably lost due to mounting medium action (see Remarks). Cuticle with transverse bands of round and large pores around the body (Figure 1). Pores larger on the head region. A very large and round pore present close to the claws on external side of all legs (pore diameter = 2.0% of body length; Figures 1, 2 A; Tables 1–2). In some legs, three or five smaller pores forming a triangle or pentagon figure present over the large round pore (Figure 2 A). Buccal armature and transversal ridges not visible at light microscope. Buccal tube long (19.8 µm) and narrow (1.2 µm) (Tables 1–2) and with double curvature (Figure 2 B). Stylet support inserted at 55.0% of buccal tube length (Tables 1–2). Pharyngeal bulb round (Tables 1–2) with large, round apophyses, three round macroplacoids of similar size (Figure 2 B) and solid, and small but distinct microplacoid (Figures 1, 2 B). Macroplacoid row: 5.4 m (27.5% of buccal tube length; Table 1). Claws slender (main branch of fourth pair of claws 4.9 m long) with long secondary branches (Figure 2 C). Short but well developed accessory points on main branches present (Figure 2 C). Lunules small, smooth and thin in all claws (Figure 2 C). Eggs unknown. Etymology The species is named in memory of Mr. Gumersindo Guil Valverde, Dr. Guil’s grandfather. Type locality Moss on rock, in oak forest at 1098 m a.s.l. in Bustarviejo Valley (Madrid, Spain; UTM 30T0437017­4521195). Repositories The holotype and paratype are deposited in the non­insect invertebrate collection of National Museum of Natural Science of Madrid (Consejo Superior de Investigaciones Científicas, CSIC) (collection number: 23.00/1). Remarks Cuticle transverse bands are not well identifiable in the paratype and in some specimens of west Madrid and Canary Islands. Eyes are visible in specimens of Minibiotus gumersindoi n. sp. from west Madrid and Canary Islands. Differential diagnosis Minibiotus gumersindoi n. sp. differs from all the other species of the genus for the presence of a very large pore in the external distal part of the leg and for a set of large pores in the proximal part of the leg. In particular Minibiotus gumersindoi n. sp. differs from other similar species (Table 3) for: ­ the presence of large and almost regular rounded pores: irregular in M. bisoctus (Horning, Schuster & Grigarick), M. ethelae Claxton, M. furcatus (Ehrenberg), M. stuckenbergi (Dastych, Ryan & Watkins), and M. vinciguerrae Binda & Pilato, and small in M. keppelensis Claxton, M. poricinctus Claxton and M. ramazzottii Binda & Pilato; ­ the absence of granulation on legs: present in M. bisoctus (Horning, Schuster & Grigarick), M. keppelensis Claxton, M. poricinctus Claxton, M. stuckenbergi (Dastych, Ryan & Watkins), M. vinciguerrae Binda & Pilato, and M. weinerorum (Dastych); ­ the absence of cuticle thickened in caudal region: present in M. ethelae Claxton; ­ the presence of three macroplacoids; two in M. scopulus Claxton; ­ the presence of smooth lunules on the fourth leg pair: with teeth in M. stuckenbergi (Dastych, Ryan & Watkins). Habitat In Cercedilla, specimens were found in rock mosses in a xerophilus landscape (xerophilus bushes: thyme, rosemary and broom) at 1228 m a.s.l.. In Embalse de la Jarosa the new species has been found in rock mosses in a pine forest (of Pinus nigra Arnold) at 1107 m a.s.l. and in the Canary Islands in rock mosses in a pine forest (of Pinus canariensis Smith) at 1460 m a.s.l. Population variability We consider the specimens collected in the different localities belonging to the same species due to the well defined morphological characters shared by these specimens. Due to the relatively small number of specimens collected in the different localities, we did not performed a statistical analyses of the morphometric data. Anyway, we report the morphometric differences identified in the populations. Morphometric differences appear when the Madrid populations (Table 1 from M1 to M2, type locality population, and from M3 to M7, west Madrid populations) and the Caldera de Taburiente (Canary Islands) population (Table 1 from CT1 to CT9) are compared. Body length, stylet support insertion length and secondary branch of claws in fourth pair of legs are larger in the Caldera de Taburiente (Canary Islands) population than in the Madrid (type locality) and the west Madrid populations (Table 2), while main branch of claws in fourth pair of legs is larger in the Madrid populations than in the Caldera de Taburiente (Canary Islands) population (Table 2). The Caldera de Taburiente population (Canary Islands) (from pine forest) has the bigger distal leg pore diameters, followed by the west Madrid population (from xerophilous and pine forest) and the type locality population (from oak forest) (Table 2). Buccal tube length and body pores diameters are larger in the type locality population than in the west Madrid and the Caldera de Taburiente (Canary Islands) populations, where their values are similar. Body length and pharyngeal width are shorter in the type locality population than in the others (Table 2). Other species of tardigrades There is no other tardigrade species that occurs always in all the four localities where we have found Minibiotus gumersindoi n. sp. Echiniscus trisetosus Cuénot is present in three of the four localities (Bustarviejo valley, Cercedilla and Caldera de Taburiente). We present other tardigrade species found together with the new species in Table 4, where information is given on which species are new records for Madrid, Canary Islands and/or the Iberian Peninsula.

Published as part of Guil, Noemi & Guidetti, Roberto, 2005, A new species of Tardigrada (Eutardigrada: Macrobiotidae) from Iberian Peninsula and Canary Islands (Spain), pp. 1-11 in Zootaxa 889 on pages 3-8, DOI: 10.5281/zenodo.170921