Macrobiotus almadai Fontoura, Pilato & Lisi, 2008, sp. nov.
Creators: name: Fontoura, Paulo
name: Pilato, Giovanni
name: Lisi, Oscar
Publisher: name: Zenodo
Year: 2008
Subjects: Biodiversity
Taxonomy
Animalia
Tardigrada
Eutardigrada
Parachela
Macrobiotidae
Macrobiotus
Macrobiotus almadai

description: Macrobiotus almadai sp. nov.
Fig. 1
Material examined: 53 specimens and 15 eggs: 3 specimens mounted in polyvinyl lactophenol collected on Túnel da Caldeira (Faial Island); 1 specimen and 1 egg mounted in Hoyer’s medium from Parque Florestal (Faial Island); 33 specimens (30 mounted in Hoyer’s medium and 3 in polyvinyl lactophenol) and 12 eggs from Lages do Pico (Pico Island); 16 specimens and 2 eggs mounted in Hoyer’s medium from Terras do Pico (Pico Island).
Type repository: Holotype (slide No. 5220) and two eggs are deposited in the collection of Binda & Pilato (Museo del Dipartimento di Biologia Animale “Marcello La Greca”, Università di Catania). Paratypes are deposited in the collection of P. Fontoura (Department of Zoology and Anthropology, Faculty of Sciences, University of Porto).
Specific diagnosis: Species belonging to hufelandi group. Cuticle smooth with some small pores (fine granulation present only on hind legs), eyes present; buccal tube narrow; buccal armature very simple with peribuccal lamellae and three dorsal and three ventral thin transversal ridges; bands of teeth not visible; pharyngeal bulb with apophyses, two macroplacoids and microplacoid; eggs with reticulated shell and processes shaped in the form of inverted goblets; reticular design delicate and very regular; terminal disc of processes with very small teeth visible only in some orientations.
Description of the holotype: Body length 340 μm, colorless, eyes present; cuticle smooth with some small circular and elliptical pores (fine granulation present only on hind legs). Buccal armature simple: only 10 peribuccal lamellae and a system of three thin dorsal and three ventral transversal ridges present. Bands of teeth not visible. Rigid buccal tube narrow, 32.4 µm long and 3.6 µm (pt = 11.1) wide externally (Fig. 1A). Stylet supports inserted on the buccal tube wall at 76.5 % of its length (pt = 76.5). Pharyngeal bulb with apophyses, two rod-shaped macroplacoids and microplacoid. First macroplacoid, with central constriction, 8.2 µm long (pt = 25.3), second 5.5 µm (pt = 17.0), microplacoid 2.7 µm long (pt = 8.3). Placoid row length 16.6 µm (pt = 51.2). Macroplacoid row length 14.0 µm long (pt = 43.2).
Claws of hufelandi type with accessory points on the main branches and smooth lunules (Figs. 1B, D). External and internal claws of the third pair of legs 9.6 µm (pt = 29.6) long and 9.5 µm (pt = 29.3) respectively. Posterior claws of hind legs 10.9 µm (pt = 33.6) long.
Eggs laid free, spherical, with reticulated shell (Figs. 1E, F) and with processes in the shape of inverted goblets (Figs. 1E, G). Diameter without processes 69–78 µm, including them 74–86 µm. On circumference 23–27 processes were present (86–110 in hemisphere). Processes up to 5.9 µm high with basal diameter of 5.1–5.5 µm. Terminal disc, 3.8–5.5 µm in diameter, may appear smooth (Figs. 1E, F), but in some orientations it shows very small teeth (Fig. 1G). Egg shell with very regular, elegant, and homogeneous reticular design (Figs. 1E, F). Margins of meshes very thin and basal meshes slightly larger than others.
Remarks: Paratypes similar to holotype in both qualitative and morphometric characters. Smallest specimen 161 µm long, largest one 394 µm.
Re-examination of some specimens and eggs collected on Pico and St. Maria Islands (Fontoura, 1985) showed that they do not belong to M. hufelandi, as previously identified, and must be attributed to the new species Macrobiotus almadai sp. nov.
Etymology: The new species is dedicated in honor to the coordinator of the Eco-Ethology Research Unit, Prof. Vitor Almada, in appreciation of his support to our studies on tardigrades.
Differential diagnosis: Macrobiotus almadai sp. nov. belongs to the hufelandi group of species. Some species of this group have narrow buccal tube and no (or almost not visible) bands of teeth in the buccal cavity (M. diversus Biserov, 1990; M. madegassus; M. humilis; M. denticulus and M. ramoli Dastych, 2005). M. almadai sp. nov. differs from them in some characters of the eggs and, in addition, from M. diversus, M. madegassus and M. humilis in having three separate dorsal ridges instead of a long single ridge; from M. denticulus in lacking a tooth in the anterior part of the buccal tube, and from M. ramoli in having the dorsomedian ridge very thin, and smooth lunules.
The new species differs from M. hufelandi in having narrower buccal tube (Tab. 1; Figs. 1A, 2A); bands of teeth in the buccal cavity not visible; stylet supports inserted on buccal tube in more anterior position (pt = 76.5 in M. almadai sp. nov. and 80–81 in M. hufelandi); slightly shorter macroplacoids (Tab. 1); slightly longer claws (Tab. 1); eggs with more delicate and regular reticular design and terminal disc of processes with smaller teeth (Figs. 1E, G, 2 B).
Characters M. almadai sp. nov. M. sandrae M. hufelandi
Holotype Smallest Largest
specimen specimen
M. almadai sp. nov. differs from M. sandrae in having narrower buccal tube (Tab. 1; Figs. 1A, 2 C); bands of teeth in buccal cavity not visible; slightly shorter macroplacoids (Tab. 1; Figs. 1A, 2 C); slightly longer claws (Tab. 1); egg shell with more delicate and regular reticular design (Figs. 1F, G, 2 D); terminal disc of processes with small teeth instead of jagged margin (Fig. 2 D).
description: Published as part of Fontoura, Paulo, Pilato, Giovanni & Lisi, Oscar, 2008, New records of eutardigrades (Tardigrada) from Faial and Pico Islands, the Azores, with the description of two new species, pp. 37-47 in Zootaxa 1778 on pages 38-40, DOI: 10.5281/zenodo.182262