1. 4British Antarctic Survey, Madingley Road, Cambridge, CB3 0ET, UK.
Diversity of tardigrades of the Americas in relation to the hypothesis of the “Great American Biotic Interchange”
Łukasz Kaczmarek1-2, Bartłomiej Gołdyn2-3, Sandra J. McInnes4, Łukasz Michalczyk5
1Department of Animal Taxonomy and Ecology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań, Poland.
2Prometeo Researcher, Laboratorio de Ecología Natural y Aplicada de Invertebrados, Universidad Estatal Amazónica, Campus Principal Km 2.1/2 via a Napo (Paso Lateral) Puyo, Pastaza, Ecuador
3Department of General Zoology, Faculty of Biology, Adam Mickiewicz University in Poznań, Collegium Biologicum, Umultowska 89, 61–614 Poznań, Poland.
4British Antarctic Survey, Madingley Road, Cambridge, CB3 0ET, UK.
5Department of Entomology, Institute of Zoology, Jagiellonian University, Gronostajowa 9, Kraków, Poland.

2. GABI (Great American Interchange)
Migration of terrestrial and freshwater animals between South and North America via Central American land connection (Isthmus of Panama)
Ca. 3 Ma ago
Mainly plants and vertebrates (mammals, rodents and birds)
What about invertebrates?

3. GABI (Great American Interchange)
Butterflies
Coleoptera
Turbellaria
Parasites of vertebrates
etc.

4. Material and Methods
1702 localities from North, South and Central America
384 species
Present vs absent data (with two ranks)
Area divided into 20 squares (25x25 degress) or 57 squares (10x10 degrees)
Statistical methods: spatial (redundancy, endemism measures) and cluster (Sorensen metric) analyses using Biodiverse 1.0 software

6. Division of the Americas into geographical units (25x25 degrees)
1. Canadian Arctic 1
2. Canadian Arctic 2
3. Alaska
4. Canada/USA 1
5. Canada/USA 2
6. Canada/USA 3
7. Canada/USA 4
8. California
9. Mexico/USA
10. USA 1
11. USA 2
12. Mexico
13. Caribbean
14. Colombia
15. Ecuador/Chile
16. Amazon 1
17. Amazon 2
18. Argentina/Chile
19. Brazil
20. Tierra del Fuego 10 11

7. Redundancy

8. Species richnes

9. Endemism

10. „Tardigrade regions” in Americas

11. „Tardigrade regions” in Americas

12. Similarities between South, North and Central America
Similarity of CA to
n-m SA and s-m NA
Similarity of n-m SA
to CA and s-m NA
Similarity of s-m NA
to CA and n-m SA
The uniqueness of the fauna of the Central American and Caribbean

13. „Tardigrade regions” in smaller units (10x10 degrees)
South and North American fauna mixing

14. North America Central America South America Galapagos Mac. crenulatus
Is.
kenodontis
Ps.brevi-
montanus
Mac.
crenulatus
Mur.
stellatus E.
dariae
Cal.
schusteri
Is.
kenodontis
Dor.
dawkinsi E.
cavagnaroi
Ram.
baumanni
Dor.
dawkinsi E.
cavagnaroi
Ps.
juanitae
Mac.
alvaroi
E. kofordi E.
virginicus
Mur.
stellatus
Cal.
schusteri
Milnesium
krzysztofi
Ps.
spinerectus
Mac.
coronatus
Ps.brevi-
montanus
Mac.
psephus
Ram.
baumanni
Milnesium
katarzynae
Mop.
schusteri
Central America E.
virginicus
Mac.
alvaroi
E. kofordi
Milnesium
katarzynae
Ps.
spinerectus
Milnesium
krzysztofi
Mop.
schusteri
Mac.
psephus
Ram.
baumanni E.
virginicus E.
dariae
Ps.
juanitae
Mac.
coronatus
E. kofordi
Galapagos
South America

15. Conclusions In general, American tardigrades are poorly known.
The best studied were inland areas of North America.
Many species were misidentified and their distribution is uncertain.
Most of the data does not show the actual ranges.
The most species rich are tropical regions, easily accessible areas and places where the number of collected samples was high.
Highest endemism is in tropics and in well studied areas.
High endemism is probably caused by scarce data from the most of the regions and by taxonomic problems from the past (species groups/ complexes, lack of complete descriptions etc.).
Coastal regions are clearly different from inland areas.

16. Conclusions
Central American fauna is unique and different from South and North American (9 to 11 regions).
South and North American faunas are more similar one to another than the faunas of both Americas are to the fauna of Central America (9 and 10 regions).
Tardigrade fauna of Central America is the most similar to the Caribbean and southernmost parts of North America and northernmost parts of South America.
Tardigrade fauna from South and North America is similar, especially in temperate and sub-polar regions, and mixing in tropical regions (squares 10x10 degrees).
Finally, some tardigrade species are distributed on both sides of Isthmus of Panama (in North, Central and South America) which seems to partially confirm the GABI hypothesis.

17. Thank you…also for your attention
Acknowledgements
I want to thanks:
My parents (they know for what)
Tardigrades because they are so cute and amazing
My students: Krzychu, Milena, Marta, Weronika and few others (thanks to them I have enthusiasm for further work)
…. and my colleagues (especially dr Bartłomiej Gołdyn who helped me with statistical analyses)
Thank you…also for your attention