Chlorophyta (green algae)

1. Chlorophyta (green algae) Lecture 8

2. OVERVIEW Eubacteria & Protists • Cyanophyta • “Phytoplankton” • Chlorophyta, Phaeophyta, Rhodophyta Vascular Plants (Gymnosperms & Angiosperms) • Seagrasses – Hydrocharitaceae & Potamogetonaceae • Saltmarshes – Poaceae, Juncaceae, etc • Mangroves – Rhizophoraceae, Avicenniaceae • Beach & Dune plants

3. Fan-Shaped Phylogenetic Tree

4. “MACRO-ALGAE” = seaweeds • Divisions: • Chlorophyta (green) • Phaeophyta (brown) • Rhodophyta (red) • Separated on basis of pigments (color) • Evolved 900-600 Mio (Cambrian) • Continental Margins – Rocky shores or lagoons predominantly.

5. Div Chlorophyta • Chlorophyta (green) – 900 spp (about 10% of known spp, rest are freshwater). • Ancestor of terrestrial plants (Kingdom Plantae) • Chl a + b, (B-carotene, xanthophylls – photoprotective role) • Uni-nucleate, also Multi-nucleate (siphonous) • 6 Orders: e.g. Ulvales, Cladophorales, Caulerpales • Cosmopolitan and tropicals

6. Algal pigments

7. Pigment Molecules CAROTENES CHLOROPHYLL

8. Enteromorpha Epiphytes Chaetomorpha Cladophora

9. Ulva Enteromorpha Halimeda Caulerpa

10. THALLUS COARSLEY - BRANCHED FILAMENT SHEET JOINTED - CALCAREOUS THICK - LEATHERY ENCRUSTING

11. Form - Function Incr productivity

12. Ulva Enteromorpha Halimeda Caulerpa

13. Why simple = more productive? • Nutrient uptake, waste removal in single cell relies on diffusion, some active uptake. • No translocation within plant necessary • Reduce boundary layer effects – promotes diffusion into cell. • No metabolic losses to structural tissues • Faster life-cycle (hrs – days)

14. Zone of little-no flow around an object/surface. Inhibits diffusion Movement promotes flow past object, breaking down boundary layer Important for algal nutrient and CO2 uptake Boundary Layers

15. Zone of little-no flow around an object/surface. Inhibits diffusion Movement promotes flow past object, breaking down boundary layer Important for algal nutrient and CO2 uptake Boundary Layers Diffusion across cells/membranes

16. r vs K selected life-strategies r = Ulva, Enteromorpha K = Halimeda, Penicillus Taxonomy generally from simple to complex:single cells, filaments, multi-filament, corticated,specialized structures Simple Structure and Succession

17. Chlorophyte taxonomy • Number of classes has increased from 1 in 1903, to 3 in 1990, to 10 in 1995. • Based on EM (2 types of cell division, flagellum ultrastructure) and RNA sequence in chloroplast and mitrochondria, DNA in nuclei. • Ancestors of terrestrial vascular plants • Class Prasinophyceae – single cell (plankton). • Class Chlorophyceae – 6 of 15 orders have seaweeds.

18. Thallus organization • Unicell flagellate – Chlamydomonas • Colonial flag – Volvox • Tetrasporal, Coccoid, Sarcinoid groups • Filamentous – Ulothrix • Thallose – Ulva • Siphonous - Caulerpa

19. Evolution VOLVOX Chlamydomonas Spyrogyra

20. Chara - muskgrass

21. Chlorophyceae taxonomy (recent) • Or. Ulvales (Ulotrichales) – Fam. Ulvaceae + 5 others • Cladophorales – Cladophoraceae + Anadyomenaceae • Acrosiphoniales– 1 order • Siphonocladales – Siphonocladaceae, Boodleaceae, Valoniaceae • Caulerpales – Bryopsidaceae, Caulerpaceae, Codiaceae, Udoteaceae, + 2 others (FW) • Dasycladales – Dasycladaceae + Acetabulariaceae

22. Cl. Chlorophyceae taxonomy Dawes, pg 122

23. Or. Ulvales Ulva

24. Or. Ulvales Enteromorpha

25. Or. Cladophorales Cladophora

26. Or. Cladophorales Anadyomene

27. Or. Siphonocladales Boodlea Siphonocladus

28. Or. Siphonocladales Holdfast Valonia

29. Or. Caulerpales

30. Or. Caulerpales

31. Or. Caulerpales Caulerpa mexicana

32. Or. Caulerpales

33. Or. Caulerpales Codium

34. Or. Caulerpales - rhizophytic “root-ball”

35. Or. Caulerpales

36. Or. Caulerpales Halimeda

37. Or. Dasycladales Dasycladus Batophora

38. Or. Dasycladales Acetabularia

39. MS Chlorophyta (1957) • Ulvales – Enteromorpha flexuosa, E. lingulata, E. plumosa, Ulva lactuca • Ulotrichaceae – Stichooccus marinus • Chaetophoraceae – Entocladia viridis, Phaeophila floridaerum, Ulvella lens • Cladophorales – Cladophora fascicularis, C gracilis, Rhizoclonium riparium. • Siphonales – Osterobium queketti • about 12 species…

40. Chlorophyta in the “news” • Ulva and Enteromorpha abundance increases in Baltic Sea / Adriatic Sea due to eutrophication – smothering seagrass and mudflats, smelly wrack driving tourists from beaches. • Enteromorpha bloom in China largest ever recorded – thought to originate from aquaculture. • Caulerpa taxifolia – Killer Algae escapes Monaco aquarium. Covers 10’000acres in Med within <10years. • Halimeda and Dictyota (brown) smother Fla Keys reef tract – response to eutrophication from septic systems? • Acetabularia used in studies of abiotic and genetic cues for algal development.

41. Chlorophyta in the “news” • Ulva and Enteromorpha abundance increases in Baltic Sea / Adriatic Sea due to eutrophication – smothering seagrass and mudflats, smelly wrack driving tourists from beaches.

42. Enteromorpha bloom seen from space! (Liu et al. 2009)

43. Enteromorpha bloom seen from space! (Liu et al. 2009) Cause: more aquaculture of seaweed (Porphyra) for sushi. Green algae a by-product. Ocean circulation moved bloom of green algae north and east, so accumulates onshore far from source population.

44. http://aquat1.ifas.ufl.edu/seagrant/cautax2.html Chlorophyta in the “news” • Caulerpa taxifolia – Killer Algae escapes Monaco aquarium. Covers 10’000acres in Med within <10years.

45. Chlorophyta in the “news” • Halimeda and Dictyota (brown) smother Fla Keys reef tract – response to eutrophication from septic systems? Orange Bay, Jamaica. Eutrophication from sugar cane fields

46. SAND KEY, FLA

47. Chlorophyta in the “news” • Acetabularia used in studies of abiotic and genetic cues for algal development.

48. Chlorophyta and Coral reefs

49. Coral Reefs Acropora - staghorn Porites – finger coral Acropora - Elkhorn Montastrea – boulder coral

50. Global Distn