Oscar Lisi

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.

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.

Notes on some tardigrades from Thailand, with descriptions of two new species

Abstract Three species of tardigrades are reported from Thailand: Pseudechiniscus quadrilobatus Iharos, 1969, Calcarobiotus (Calcarobiotus) digeronimoi sp. n., and Mixibius sutirae sp. n. Calcarobiotus (C.) digeronimoi sp. n. has claws of Calcarobiotus type; those of the first three pairs of legs have a medial and a lateral spur, those of the hind legs lack basal spurs. Mixibius sutirae sp. n. has a densely sculptured dorsal cuticle and two macroplacoids; it lacks lunules and other thickenings on the legs. It is similar to Mixibius ornatus Pilato et al., 2001, from which it differs in characteristics of the cu‐ticular sculpture and by having the ventral surface unsculptured.

Hebesuncus mollispinus (Eutardigrada, Hypsibiidae), a new species from maritime Antarctica

A new species of eutardigrade, Hebesuncus mollispinus sp. nov. is described from Charcot Island, maritime Antarctica. The three known species of Hebesuncus are either widespread with questionable reports from the Antarctic (H. conjungens) or endemic to maritime and continental Antarctica (H. ryani and H. schusteri). Hebesuncus mollispinus sp. nov. differs from its congeners in terms of egg morphology and is further differentiated from H. ryani via a longer buccopharyngeal tube, claw shape and length; and from H. schusteri via a narrower bucco-pharyngeal tube and shorter claws.

Eutardigrada from New Zealand, with descriptions of two new species

Abstract We review some species of Macrobiot‐idae of New Zealand, and describe two new species: Macrobiotus hapukuensis sp. n. and Macrobiotus semmelweisi sp. n. Macrobiotus hapukuensis sp. n. belongs to the richtersi group; it differs from the other species of the group in some characters of the eggs, and from some of them in lacking eyes and dots on the legs or in the shape of the claws. Macrobiotus semmelweisi sp. n. has bands of gibbosities, each with a round or elliptical pore; two macroplacoids and a microplacoid; dorsal transversal ridges of the buccal armature joined to one another and forming a unique thin transversal ridge; eggs with slender conical processes with a long, thin, flexible, terminal portion; egg shell clearly dotted.

Four new species of the Diphascon nobilei group (Eutardigrada, Hypsibiidae)

The existence of a group of species similar to Diphascon (Diphascon) nobilei is shown. These species have some common characteristics: a well‐evident drop‐shaped thickening between the buccal tube and the pharyngeal tube, pharyngeal bulb, more or less elongate, with three rod‐shaped macroplacoids and microplacoid, claws of the hind legs different from those of the first three pairs of legs in having a very wide basal portion and indented basal margin, basal spurs also present on the external claws and, in some cases, also on the internal claws of the first three pairs of legs. Four new species of this group are described: Diphascon (D.) serratum, D. (D.) nelsonae, D. (D.) platyungue, and D. (D.) hydrophilum. They differ from one another in the dimensions and shape of the claws; in some cases the difference also affects the value of the ptd index relative to the insertion point of the stylet supports, the buccal and the pharyngeal tube length or the macroplacoid length.

Mixibius parvus sp. nov. and Diphascon (Diphascon) ziliense sp. nov., two new species of Eutardigrada from Sicily.

We describe two new sympatric species of Sarsiellidae from coastal Florida, USA: Eusarsiella bryanjuarezi sp. nov. and Eusarsiella eli sp. nov. We also present a morphological character matrix and maximum likelihood phylogenetic analysis for Sarsiellinae based on original species descriptions, representing 139 sarsiellins (including E. bryanjuarezi and E. eli). While support values across the phylogeny are low, E. bryanjuarezi and E. eli form a sister group pair with 68 % bootstrap support. Our phylogeny also showed support for six other sympatric sister-species pairs, distributed across Sarsiellinaes range, which may be candidates for the study of speciation and niche differentiation. Similar to other analyses of myodocopids, our Sarsiellinae phylogeny recovered only three monophyletic genera: Anscottiella, Cymbicopia, and Chelicopia, indicating that characters used in taxonomy may often be homoplasious. Because of our finding of multiple polyphyletic genera, including the two most speciose genera in the subfamily (Eusarsiella and Sarsiella, the type genus) Sarsiellinae is a strong candidate for taxonomic revision.

New description of Echiniscus viridis Murray, 1910 and remarks on the viridis group

Abstract The type material of Echiniscus viridis Murray, 1910 is probably lost. Here we give a new description of this species from two specimens from the type locality (Hawaiian Islands) deposited in the collection of the late Robert O. Schuster (Bohart Museum of Entomology of California, Davis, United States). The validity of the other species of the group viridis is confirmed, and the need to confirm the records of E. viridis from geographical areas different from the type locality is stressed.

Echiniscidae from the Sierra Nevada de Santa Marta, Colombia, new records and a new species of Bryodelphax Thulin, 1928 (Tardigrada)

Abstract Three species of Echiniscus are recorded for the first time from Colombia: Echiniscus dariae, Echiniscus kofordi, and Echiniscus perarmatus. In addition, the description of the new species Bryodelphax kristenseni sp. n., is mainly based on the presence of ten paired plus two unpaired granularly sculptured ventral plates, the dorsal plate ornamentation with superficial irregular pores, no spine on the anterior legs, and the hind legs without papillae or dentate collar.