Brussels, 28-‐29-‐30 September
TARDIGRADAReinhardt Kristensen (University of Copenhagen, Zoological Museum, Denmark)
Roberto Guidetti (University of Modena and Reggio Emilia, Italy)
Head, 4 metameric segments, each one with a pair of legs with digits and claws at the extremitiesPiercing-‐sucking feeding apparatus.
Brussels, 28-‐29-‐30 September
Water bears
Described from all seas, marine tardigrades are part of the meiobenthos and occur in intertidal and subtidal areas down to the abyss (4690 m).
Interstitial, epibenthic, or associated to algae and other invertebrates(e.g. barnacles, sea cucumber)Cryptobiosis (anhydrobiosis, cryobiosis, osmobiosis) also in 2 marine species in intertidal zone (on barnacles or on lichen Lichina).
No taxonomic key for marine species (one is in preparation).Taxonomic key for limno-‐terrestrial genera: Pilato & Binda. 2010. Zootaxa2404: 1–54.
Small animals (100-‐1000 µm)Marine, brackish, freshwater, & terrestrial habitats,
all over the world for Artic to Antarctic.
Marine and freshwater environments are the least studied.
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Taxonomic information
197 marine tardigrade species (16%) out of 1220 tardigrade species.Arthrotardigrada (marine) greatest morphological diversity.
8 families, 43 genera, 185 species
40 species, 8 genera, distributed in 4 families in EutardigradaFor review: Nelson, Guidetti, Rebecchi. 2015. Phylum Tardigrada. Ecology and General Biology: Thorpand Covich’s Freshwater Invertebrates. Academic Press (Elsevier Inc.)
Few exclusively/obligate freshwater species: 1 species, 1 genera, 1 family in Heterotardograda
Phylogenetic relationships within the Panarthropoda unresolved
TardigradaArthopodaOnychophoraTardigradaArthopodaOnychophoraHeterotardigrada
Eutardigrada
Arthrotardigrada (all marine)Echiniscoidea (terrestrial, 2 genera marine)
Apochela (limno-‐terrestrial)Parachela (limno-‐terrestrial, 1 genera secondarily marine)
Phylogeny within Tardigrada: Heterotardigrada (Jorgensen, A., Kristensen, R.M., 2004.Mol. Phyl. Evol. 32, 666–670.)Eutardigrada (Bertolani et al. 2014. Mol. Phyl. Evol. 76, 110–126)
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ChecklistOnline updated check list of Tardigrada species http://www.tardigrada.modena.unimo.it/
Guidetti & Bertolani. 2005. Zootaxa.
Status in WoRMS: all marine species are listed, but most of them lack reference data and data on their distribution.
The Zoogeography of Marine TardigradaKaczmarek et al. 2015 Zootaxa (in press)