Echiniscus scabrospinosus Fontoura, 1982

Fontoura, Paulo, Pilato, Giovanni & Lisi, Oscar, 2008, Echiniscidae (Tardigrada, Heterotardigrada) from Faial and Pico Islands, the Azores, with the description of two new species, Zootaxa 1693, pp. 49-61 : 55-58

Echiniscus scabrospinosus Fontoura, 1982

Material examined: An adult female collected from a moss sample from Faial Island (Miradouro da Praia Norte). The specimen was mounted in polyvinyl lactophenol.

The specimen, whose measurements are indicated in Table 3 , in our opinion, belongs to the species Echiniscus scabrospinosus notwithstanding the absence of the cirrus D. We have this opinion because, this character excluded, our specimen is perfectly similar to the holotype of E. scabrospinisus for both metric and qualitative characters. In particular we stress the presence of two characteristics of this species: a) in the cuticular translucent discs a small dark ring is present from which dark lines irradiate ( Fontoura, 1982; Binda & Pilato, 1995); b) the particular shape of the appendage D d that is wide and with a round tip.

In our opinion, considering the situation ascertained in many other species, the absence of lateral appendage D is compatible with an intraspecific variability. The range of the individual variability of this species is not known since only three specimens have been reported: the holotype from the Portugal, one specimen from Tanzania ( Binda & Pilato, 1995), and the present specimen from the Azores. The specimens from China attributed by Beasley & Cleveland (1996) to E. scabrospinosus do not belong to this species.

Echiniscus viridianus Pilato, Fontoura & Lisi, 2007

Material examined: Three adult females collected at Lages do Pico, Pico Island.

The body length was comprised between 231 and 259 µm; the color was reddish-brown for live specimens and green when mounted in Hoyer’s medium and observed in transmitted light at phase contrast. The species, already recorded in the Azores, (Pilato et al. 2007) is also present in North America (Alabama and New Mexico).

Material examined: Holotype, four paratypes and an exuvium with two eggs from a moss sample collected in Terras do Pico, Pico Island. All the specimens were mounted in Hoyer’s medium with a small amount of potassium iodide.

Type repository: The holotype (slide N. 5201) is deposited at the Museum of the Dipartimento di Biologia Animale “Marcello La Greca”, Università di Catania in the collection of Binda & Pilato. The four paratypes and the exuviae (slides BII-17 to BII-21) are deposited in the collection of P. Fontoura at the Department of Zoology and Anthropology, Faculty of Sciences, University of Porto.

Specific diagnosis: Small Bryodelphax without ventral plates but with small supplementary plates between paired plates; plate ornamentation with black dots and light spots; hind legs with a fringe with short and wide triangular teeth.

Description of the holotype: The body and the eye spots are red. Total body length about 135 µm long. Scapular plate undivided ( Fig. 3 A). First and second median plates divided into two parts ( Fig. 3 A). Third median plate with a roundish posterior edge, undivided but having a transversal fold ( Fig. 3 B). Paired plates divided into an anterior and a posterior part by a transversal and thin band without granulation ( Fig. 3 A & B) Terminal plate characteristically faceted by two longitudinal and thin folds ( Fig. 3 B). Small supplementary plates, difficult to see, between paired plates ( Fig. 3 A & B). Ventral plates absent.

Dorsal plates covered with tiny and regularly distributed granulation (0.4–0.7 µm in diameter), the largest being on the scapular and the terminal plate, the smallest on the posterior portion of the paired plates ( Fig. 3 A & B). Very fine granulation, almost invisible, on the anterior portion of paired plates and on the median plates. In addition to the granulation, slightly larger (0.6–0.8 µm in diameter) and irregularly distributed pores are present. The pores occur, more densely distributed, on the anterior edge and on the lateral portions of the plates ( Fig. 3 A & B). The supplementary plates are ornamented with very fine granulation and pores but this ornamentation is very difficult to see. All legs with small dots.

Apart from cephalic cirri, only the lateral filament A is present (27.5 µm long = 20.4 % of body length).

Internal cephalic cirrus 5.7 µm long; external cephalic cirrus 9.5 µm long; cephalic papilla 2.9 µm long; clava about 3.0 µm long ( Table 4 ).

Spine on the first pair of legs and papilla on the fourth pair of legs absent. Dentate fringe on the fourth pair of legs present with a few (4 in the holotype; 5 in paratype BII-20) small triangular teeth ( Fig. 3 D).

External claws smooth; internal claws with a very small spur (less than 1 µm) oriented towards the base ( Fig. 3 C). Claws of the hind legs 6.4 µm long. All claws with long and fine extremities strongly bent.

Measurements of some structures of the holotype and of the smallest and the largest paratype are given in Table 4 .

Eggs are laid in exuviae. The two eggs examined have a diameter of 49.0 and 51.1 µm.

Etymology: According to one version of the legend, the lost continent of Atlantis was located in the Azores. The name atlantis means inhabiting Atlantis .

Differential diagnosis: Excluding Bryodelphax lijiangensis Yang, 2002 that also has lateral appendages B, C, D and E, all other species of the genus are very similar to one another and in many cases it is difficult to distinguish one species from the others. This is also true because some descriptions are very short, and the presence or absence of some characters is not specified.

B. atlantis sp. nov. differs from B. weglarskae B. sinensis and B. iohannis in lacking ventral plates; it differs from B. parvulus , B. ortholineatus Bartoš, 1963 , B. crossotus Grigarick, Schuster & Nelson, 1983 and B. asiaticus Kaczmarek & Michalczyk, 2004 mainly in having a dentate fringe on the hind legs; from B. dominicanus ( Schuster & Toftner, 1982) in having a dentate fringe on the hind legs and in details of the plates sculpture; it differs from B. brevidentatus mainly in having lateral plates; from B. amphoterus mainly in lacking spurs on the external claws; from B. alzirae Du Bois-Reymond Marcus, 1944 , B. mateusi and B. tatrensis mainly in lacking the papilla on the hind legs. From E. mateusi it also differs in having the dentate fringe with shorter teeth ( Figs. 3 D & E).

Considering the difficulties in distinguishing from each another the species of Bryodelphax , we think opportune to provide here a dichotomous key to all the known species of the genus.

Figures

FIGURE 3. Bryodelphax atlantis sp. nov. A, B, habitus (paratype); arrows indicate supplementary plates; C, claws of the second pair of legs of the holotype; the spur is visible on the internal claws. D, dentate fringe on one of the hind legs of a paratype. E, B. mateusi, fourth pair of legs; some long teeth of the dentate fringe are visible. Scale bar = 10 µm.

Tables

TABLE 3. Measurements (in µm) of some structures of the found specimen of E. scabrospinosus (% bo = percentage of body length; % sc = percentage of scapular plate length).

Character	µm	%bo	%sc
Body length	181	-	-
Scapular plate length	33.1	18.3	-
Internal cephalic cirrus	10.4	5.7	31.4
External cephalic cirrus	14.0	7.7	42.3
Cephalic papilla	6.0	3.3	18.1
Clava	4.1	2.3	12.4
Lateral appendage A	44.4	24.5	134.1
Lateral appendage C	6.1	3.4	18.4
Lateral appendage E	8.0	4.4	24.2
Dorsal appendage D d	14.9	8.2	45.0
Spine on legs I	?	?	?
Internal claws I	10.9	6.0	32.9
External claws I	9.9	5.5	29.9
Internal claws II/III	10.2	5.6	30.8
External claws II/III	9.0	5.0	27.2
Internal claws IV	12.3	6.8	37.2
External claws IV	11.6	6.4	35.0
Papilla on legs IV	3.0	1.7	9.1
Spur on legs IV	2.0	1.1	6.0
Number of teeth on dentate fringe	9	-	-
Bryodelphax atlantis sp. nov. Fig. 3A–D, Table 4