Giovanni Pilato

Biogeography and Limno-terrestrial Tardigrades: Are They Truly Incompatible Binomials?

Abstract Due to the passive dispersal, tardigrades have been traditionally considered unsuitable for biogeographical studies. However, this paper provides some biogeographical and biological data supporting the possibility of using those animals to solve biogeographical problems at continental level.

Correlations between cryptobiosis and other biological characteristics in some soil animals

Abstract Attention is focused on soil rotifers, gastrotrichs, nematodes and tardigrades which are active solely when enveloped by a water film and survive freezing and desiccation by virtue of their ability to enter cryptobiosis. All these groups share some morphological and biological characteristics, some of which have a manifest adaptive significance, while in others the adaptive value is less evident. Lastly, some of these features still want elucidation, e.g. the maintenance of continuous thelytokous parthenogenesis even in lineages very rich in species (in rotifers and gastrotrichs entire orders are so characterized) over extremely extended periods of time. From the analysis of characteristics common to the groups surveyed, some problems, for which a unitary solution is formulated, have emerged: a) the marked uniformity in morphology and size of the four groups; b) the greater morphological uniformity of soil and freshwater forms with respect to marine ones; c) the existence of a greater number of s...

Three new species of Diphascon of the pingue group (Eutardigrada, Hypsibiidae) from Antarctica

Abstract This paper contributes to the knowledge of the pingue group of species within the genus Diphascon. Three new species are described, Diphascon (D.) polare, D. (D.) dastychi and D. (D.) victoriae, from Victoria Land (Antarctica); they differ from other species of the pingue group in characters of the bucco-pharyngeal apparatus. D. polare and D. victoriae differ also in the claw shape. A key is provided to the Diphascon pingue group.

Remarks on some tardigrades of the African fauna with the description of three new species of Macrobiotus Schultze 1834

Ten species of tardigrades are recorded. Three of them, Macrobiotus radiatus, Macrobiotus vanescens, and Macrobiotus iharosi are new for science; two species, Macrobiotus sapiens Binda & Pilato 1984 and Isohypsibius kristenseni Pilato et al. 1989, are new for the African fauna. Macrobiotus radiatus n. sp. differs from the other species of the harmsioorthi group in the characters of the eggs and in other characters regarding various structures (buccal armature, or placoids length, or the insertion point of the stylet supports, or the claws length). Macrobiotus vanescens n. sp. is similar to Macrobiotus richtersi Murray 1911 and to Macrobiotus peteri Pilato et al. 1989 but differs from them in some characters regarding the bucco-pharyngeal apparatus, the claws and the eggs. Macrobiotus iharosi n. sp. differs from Macrobiotus echinogenitus Richters 1904 in the characters of the eggs, and from Macrobiotus sapiens Binda & Pilato 1984 in some characters of the bucco-pharyngeal apparatus and of the claws.

Milnesium tetralamellatum, new species of Milnesiidae from Africa (Eutardigrada)

A new species of Milnesiidae is described, Milnesium tetralamellatum, from Tanzania. It differs from Milnesium tardigradum Doyere 1840 essentially by having four peribuccal lamellae instead of six.

Geonemy, ecology, reproductive biology and morphology of the tardigrade Hypsibius zetlandicus (Eutardigrada: Hypsibiidae) with erection of Borealibius gen. n.

The morphology, biology and geographic distribution of Hypsibius zetlandicus (Murray 1907) are considered. Scanning electron microscopy (SEM) and/or light microscopy (LM) analyses have been carried out on H. zetlandicus and the type species of Hypsibius: Hypsibius dujardini (Doyère 1840), with particular emphasis on the buccal–pharyngeal apparatuses. Some unusual characteristics of this apparatus in H. zetlandicus lead us to the erection of the new genus Borealibius, to which H. zetlandicus (Borealibius zetlandicus comb. n.) is transferred. In the light of new discoveries of this species from polar, sub-polar and alpine regions, and based on the available bibliographic references, we hypothesize a boreo–alpine distribution for this species. The presence of traits that are unusual and rare (in other tardigrade species) have been observed whilst analyzing the reproductive biology and ecology of B. zetlandicus (i.e., the presence of hermaphroditism, parental care and the colonization of very different substrates).

Notes on tardigrades of the Seychelles with the description of three new species

Abstract Three new species are described for the Seychelles: Calcarobio‐tus (Discrepunguis) tetrannulatus sp.n., Macrobiotus gerlachae sp.n. and M. pseudonuragicus sp.n. Calcarobiotus (Discrepunguis) tetrannulatus sp.n. differs from all of the known species of the subgenus by having a smooth cuticle with fine dots, by lacking eyes, by having one lateral and one medial spur on the bases of the claws on the first three pairs of legs, and by having a crown of teeth lying in a single row (and not a band) in the caudal portion of the buccal cavity. Macrobiotus gerlachae sp.n. belongs to the richtersi group and M. pseudonuragicus to the harmsworthi group; each one differs from the other species of the respective group in some characters of the eggs and in other characters (e.g. the absence of eyes, the presence of cuticular dots, and details of the bucco‐pharyngeal apparatus and of the claw shape). The list of the species of terrestrial tardigrades of the Seychelles and some considerations on the tardigradological fauna of this archipelago are provided.

Notes on South American tardigrades with thedescription of two new species: Pseudechiniscusspinerectus and Macrobiotus danielae

Five species of tardigrades from South America are recorded, two of which, Pseudechiniscus spinerectus and Macrobiotus danielae, are new to science, and one, Doryphoribius flavus (Iharos 1966), is new for South America. Pseudechiniscus spinerectus differs from P. bidenticulatus Bartoš 1963 and P. bartkei Weglarska 1962 by having median plate 2 divided into two portions, spines of the pseudosegmental plate more developed; it differs from P. bidenticulatus by having inner claws with a spur; it differs from P. bartkei by having the caudal portion of the scapular plate faceted, more dense plate sculpture with dot size increasing from the head to the terminal plate, striae joining the dots to each other less evident. P. spinerectus differs from P. ramazzottii Maucci 1952 and from P. brevimontanus Kendall-Fite & Nelson 1996 in the following features: spines of the pseudosegmental plate more developed, dots of plate sculpture joined to each other by striae. it differs from P. ramazzottii also by having the papilla of the hind legs clearly shorter; it differs from P. brevimontanus also for some details of the ventral cuticular sculpture. Macrobiotus danielae belongs to the richtersi-group; it is very similar to Macrobiotus vanescens Pilato et al. 1991 from which it differs in the following features: smaller body size, wider buccal tube, slightly longer microplacoid, more slender claws, some characters of the eggs (reticular sculpture of the conical processes with less prominent ridges; less evident apical indentation; basal areolae smooth).

Diphascon (Adropion) Tricuspidatum, a new species of eutardigrade from Antarctica

Abstract A new species of freshwater eutardigrade, Diphascon (Adropion) tricuspidatum sp. nov., is described from Antarctica. It has a narrow bucco-pharyngeal tube without drop-shaped thickening, a pharyngeal bulb with small apophyses, three short macroplacoids and a small microplacoid, and very long outer claws with long and divergent accessory points.

Three new species of eutardigrades from the Seychelles

Abstract Three new species of tardigrades are described from the Seychelles: Macrobiotus pseu‐docoronatus, Macrobiotus danielisae, and Hypsibius seychellensis. Macrobiotus pseudocoronatus sp. n. belongs to the Macrobiotus harmsworthi group but it can be distinguished by the presence of very small cuticular tubercles. It also differs from some other species in the group by having eye spots, or by characters of the claws, or by details of the bucco‐pharyngeal apparatus, or by some characters of the eggs. Macrobiotus danielisae sp. n. belongs to the Macrobiotus richtersi group. It differs from the other species in the group by the characteristics of the cuticular sculpture and, from some of them, or by lacking eye spots, or by characters of the claws, or by details of the bucco‐pharyngeal apparatus, or by some characters of the eggs. Hypsibius seychellensis sp. n. differs from Hypsibius dujardini (Doyère, 1840) by having a slightly narrower buccal tube of more uniform width (in H. dujardini the posterior portion of the tube is wider than the anterior portion), and shorter claws. It differs from H. iskandarovi Tumanov, 1997 by lacking lunules and cuticular bars on the first three pairs of legs. It differs from Hypsibius allisoni Horning, Schuster & Grigarick, 1978 by having a septulum instead of an almost invisible microplacoid, and more slender claws with a longer basal portion.