Tardigrades of North Carolina
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View PDFHypsibiidae Members: 213 NC Records

Hypsibius convergens (Urbanowicz, 1925) - No Common Name


Habitus, ventral, DIC
Taxonomy
Class: EutardigradaOrder: Parachela Family: HypsibiidaeSubfamily: Hypsibiinae Checklist Number: 1260.0
Taxonomic Comments: Probably a species complex in need of integrative taxonomic examination.
Species Notes: Mostly terrestrial. Apparently cosmopolitan, broadly reported from USA.
Identification
Online resources:Online Photographs: Google, GBIF                                                                                 
Species Description: Length up to 400 µm; eyes present, sometimes small, sometimes of great size. Buccal tube rather narrow, from 1.5 to 1.7 µm in diameter, with appendices of insertion for the muscles in the form of a hook. The pharynx is - in optical section - a rather elongated oval (reported length to width ratio of about 1.3:1) and contains apophyses and 2 macroplacoids which are wide rods and the length of the first with respect to the second is reported 3:2; sometimes the first rod appears constricted in the middle and the second assumes the form of an oval granule. In general lacking the microplacoid; when present, it is nevertheless very small. Doubleclaws of each leg of very different size. The basal branch is inserted very low on the secondary branch, near the base, so that the common branch of the claw is very short. Deposited in the exuvium are 1 to 7 eggs, smooth oval or spherical. H. convergens is near to H. microps and H. pallidus: it can be distinguished from these two species by the elongated pharynx, by the shape of the placoids (which in the other two species are short granules), and by the more massive and divergent claws. It is however advisable to make clear that these characters do not always appear very evident, and in many cases certain determination requires considerable experience. H. convergens is also very similar to H. dujardini: this last species has however placoids a little more slender and longer, has a more evident microplacoid, and has decidedly more developed claws. Also in this case, especially for material collected in water, in the interstitial environment, or in wet moss a certain determination may be very difficult. H. convergens has been collected almost everywhere, in Europe (including Italy), North and South America, on Fernando Poo Island (western Africa), on Kerguelen Island, in India, Turkey, at 5,500 m altitude on Himalaya (pigmentation of brown color), in the Arctic: but it is necessary to keep in mind the possibility of possible error in the determination of the species. Type loc.: Wilna (Poland).
- Ramazzotti & Maucci 1983

Length 160-310 µm. The body is white, eyes are present. Cuticle smooth. Mouth tube 28 µm long, 2.5 µm wide, with distinct apophyses (dimensions in a specimen 275 µm long). Pharynx oval (25 x 20 µm) with two macroplacoids. No microplacoid. First macroplacoid slightly constricted in its middle. Macroplacoid lengths; 1st - 4.5 µm, 2nd - 2.8 µm; their width 1.5 µm. Claw main branches with small accessory spines. At the claw bases of 4th pair there occur small cuticular thickenings. Outer claws of 4th pair of legs 18 µm long; the length of its main branch 12 µm, the base height amounts to 7 µm. Exuviae with 1-4 smooth eggs. The studied specimens showed a great variability in the shape and size of placoids and claws. Furthermore in several of them, behind the macroplacoids I have found very fine cuticular granules (microplacoids ?!). However, they were distinctly smaller than the microplacoids in H. dujardini. In my opinion H. convergens is a complex species requiring a revision. Unfortunately, the type-material of this species does not exist. Tychoalpine species, rather frequent and numerous, widely distributed in Poland. Euryhygric and mesocalciphilous forms more frequent on carbonate bedrock. It was collected in almost all studied habitats. A geopolitan species.
- Dastych 1988
Body Length: Up to 400 microns.
Key Characters: Two rows of macroplacoids, 1st<2nd.
Key Character Images
ID Requirements: Identifiable only by close inspection of key characters or by DNA analysis.
Distribution in North Carolina
Distribution:
County Map: Clicking on a county returns the records for the species in that county.
Dates:
 High Mountains (HM) ≥ 4,000 ft.
 Low Mountains (LM) < 4,000 ft.
 Piedmont (Pd)
 Coastal Plain (CP)

Click on graph to enlarge
Habitats and Life History
Habitats: Soil / leaf litter, tree moss, tree lichens, rock moss, also occurs in streams.
Abundance: Common. This species makes up 3.87% of terrestrial specimens collected in the Great Smoky Mountains National Park.
Diet: Probably herbivorous.
Reproduction: Smooth eggs laid in shed exuvium.
Observation Methods: DIC, PC.
Wikipedia

 Photo Gallery for Hypsibius convergens - No common name

Photos: 7

Recorded by: Bartels on 2002-11-23
Haywood Co.
Comment: antero-lateral, DIC		Recorded by: Bartels on 2002-11-23
Haywood Co.
Comment: Drawing by Ramazzotti & Maucci 1983
Recorded by: Bartels on 2002-11-23
Haywood Co.
Comment: Habitus, ventral, DIC		Recorded by: Bartels on 2002-11-23
Haywood Co.
Comment: Claws, DIC
Recorded by: Bartels on 2002-11-23
Haywood Co.
Comment: Claws, PC		Recorded by: Bartels on 2002-11-23
Haywood Co.
Comment: Buccal apparatus, DIC
Recorded by: Bartels on 2002-11-23
Haywood Co.
Comment: Habitus, lateral, DIC