Stream Team 2019

1. Stream Team 2019 ~ DARTERS
Dr. Andor Kiss
Director of Center for Bioinformatics & Functional Genomics
Miami University
February 2019
Photo credit: Zach Alley

2. Stream Team 2019 ~ DARTERS
● Introduction/Basics
● Anatomy
● Taxonomy
● Distribution
● Importance
● Physiology
● Breeding
● Habitat
● Conservation

3. Stream Team 2019 ~ DARTERS
Handbook of Darters. L. Page. (1983). TFH Publications.
● Ctenoid scales
● Two dorsal fins
● Connected
● First with spines
● Second with soft rays
● One to Two anal fins
● Pelvic fins (thoratic)

4. Stream Team 2019 ~ DARTERS

5. Stream Team 2019 ~ DARTERS
● Internal anatomy of the percid fishes, specifically darters:
● Lack scales on the belly
● Lack a swimbladder
● Lack of swim bladder is thought to benefit darters
● Negatively bouyant; therefore they sink, or are able to “sit” on the
bottom of stream beds in fast flowing waters
● Makes darters a bit more difficult to sample (catch) –
electroshocking is not effective means of enumerating darters

6. Stream Team 2019 ~ DARTERS
Mississippi Watershed

7. Stream Team 2019 ~ DARTERS
● ‘DARTERS’ commonly refer to the fishes restricted to North
America*
● Mississippi River System
● Drainages of the Great Lakes, Hudson’s Bay, Atlantic Coast, Gulf of
Mexico, and Pacific Coast New Mexico
● Approximately 250 species as of 2019 (depends on reference)
– 148 species in 1983
● Perch like fishes – classic “teleost” in the Mid-West
● Four GENERA (Percina, Etheostoma, Crystallaria, and Ammocrypta)
* South American DARTERS are from the Family Crenuchidae

8. Stream Team 2019 ~ DARTERS
● Darters are part of the genera known as Etheostoma
● Recent molecular (genetics) work by Near et al. (2011)
suggested that darters are not monophyletic (not all one group)
● This means that the historical grouping has some issues
● Not unusual for molecular phylogenetics to revise established
phlyogenies
– Should all morphological work be subjected to molecular validation?
– Which should take precedence?
– How does one read the literature, once a revision occurs?

9. Stream Team 2019 ~ DARTERS
● Taxonomic problems within Darters
● There is no fossil record for darters in North America
– Difficult to calibrate the phylogenetic analyses
– Must use closely related groups wherein a fossil record exists
● Very recent and very diverse radiations (lots)
– Genetic changes are not as great (?)
– Basically, there are a lot of darters (~250 species) and some are extremely similar to each
other – both morphologically and genetically
● Introgression (mixing) of mitochondrial DNA between closely related species
– Thus, using mtDNA genes (common) for analyses is problematic

10. Stream Team 2019 ~ DARTERS
● Taxanomic resolution(s)?
● Use genetic markers that vary in evolutionary rate changes:
– Fast Evolving: mitochondrial cytochrome b, or cytb
– Medium Evolving: first intron of S7 ribosomal gene
– Slow Evolving: exon 3 of RAG1
● Use these three genes as a concatemer to analyse taxa
Gene 1 Gene 2 Gene 3
SLOW MEDIUM FAST

11. Stream Team 2019 ~ DARTERS
Alignment of the partial sequence of mitochondrial cytochrome b (mt Cytb) gene from chicken (Gallus gallus), Japanese quail (Coturnix
japonica), muskovy duck (Cairina moschata), laughing dove (Streptopelia senegalensis) and rock pigeon (Columba livia). Sequences were
aligned using CLC Main Workbench program. Dots indicate sequence identity.
Molecular phylogeny of some avian species using Cytochrome b gene sequence analysis (2015). Iranian Journal of Veterinary Research.
16(2):218-222

12. Stream Team 2019 ~ DARTERS
● Each gene will give
slightly different
topology
● Which one to choose?
● Combine & choose
consensus tree
● 50% Majority Rule is a
common compromise

13. Stream Team 2019 ~ DARTERS
● Distribution of Darters → Ohio
● 24 species of darters in Ohio (Trautman, 1986)
● Recently, ODNR puts the number at 19
– Pollution is believed to have eliminated five others
● Seven are listed as endangered, threatened or “of special concern”.
● One species that is ‘vulnerable’ is the spotted darter
● Etheostoma maculatum

14. Stream Team 2019 ~ DARTERS
● Spotted Darter

15. ● International Union for the Conservation of Nature (IUCN)
● Initiated a “Red List” in 1965
● Most comprehensive listing of endangered and threatened species
● Has become the de facto inventory of ALL species and taxa
● Ranks them regardless of conservation status
● NGO (non-governmental organisation)
● UK in origin
● Official Website: https://www.iucnredlist.org/

17. Stream Team 2019 ~ DARTERS
● Importance → Why should we can about Darters?
● They are indicators of stream health
● Oxygenation
● Silting, or lack of silting
● Pollution is very detrimental to their survival
● Both directly and indirectly indicated stream and ecosystem health
● “Canary in a Coal Mine” for conservation and stream restoration

18. Stream Team 2019 ~ DARTERS
● Breeding & Reproduction
● Occurs in the spring
● Males are extremely colourful and use their pigmentation to attract
mates
● Example: Orangebelly Darter (Etheostoma radiosum)

19. Stream Team 2019 ~ DARTERS
Orangebelly Darter – Arkansas, Oklahoma, Texas

20. Stream Team 2019 ~ DARTERS
● Orangebelly darter reaches sexual maturity at one year
● Sexual dimorphism (males are larger)
● Females appear very ripe
● Overall, fecundity is low, as is common in most darters
● “The fertilized egg of the orangebelly darter is yellowish in color,
spherical, transparent, demersal and adhesive. The eggs are laid
singly or in clusters of up to 12. The diam of fertilized eggs ranges
in size from 1.2 to 1.5 mm.”

21. Stream Team 2019 ~ DARTERS
● Habitat/Conservation
● Most darters live in riffle waters, fairly rapid flowing
● Small pebbles and/or rocky bottoms
● Low silt areas → silt prevents them from spawning
– Likely prevents eggs from attaching to substrate/algae
● High oxygenation → poor O2
→ loss of darters
● Darters are food for larger, economically important fishes
● Sauger, walleye, perch

22. Stream Team 2019 ~ DARTERS
Etheostoma flaballere – Fantail Darter

23. Stream Team 2019 ~ DARTERS
Etheostoma rufilineatum – Redline darter

24. Stream Team 2019 ~ DARTERS
Etheostoma spectabile – Orangethrout darter

25. Stream Team 2019 ~ DARTERS
Etheostoma bellus – Orangefin darter

26. Stream Team 2019 ~ DARTERS
Etheostoma exile – Iowa darter

27. Stream Team 2019 ~ DARTERS
E. blennioides – Greenside darter E. variatum – Variagate darter

28. Stream Team 2019 ~ DARTERS
E. zonale – Banded darter E. spectabile – Orangethrout darter