Triphasic Life Histories :Terminology Post- fertilization Events Distinguishing between Orders of Florideophyceae Connecting filament or Ooblast filament = tube that carries the zygote nucleus from fertilized egg to internal auxiliary cell where it is cloned and differentiates into carpospores (in some Orders!) Auxiliary cell = vegetative cell (N) that receives the 2N zygote nucleus after fertilization (in some Orders!) cp Auxiliary cell present oo Gonimoblast = 2N filaments bearing carposporangia in the carposporophyte (ALL Auxiliary branch & carpogonial Auxiliary cell absent Florideophyceans have this) branch arise from same supporting cell Gominoblast initiated from carpogonium Auxiliary cell present Gonimoblast initiated from a fused carpogonium Ooblast filament transfers & auxiliary cell zygote nucleus to auxiliary cell Gonimoblast initiated from auxiliary cell Division: Rhodophyta- 7117 species 3.Class: Florideophyceae Auxiliary cell absent 3.Class: Florideophyceae-6767 species 1.Order Nemaliales Gominoblasts initiated from carpogonium Pit plugs characterized by 2 cap layers Order: 29 orders but we will focus on 5 2N carpospores 1. Nemaliales -273 species Spermatium on gonimoblast 2. Rhodomeniales-382 species filaments 3. Ceramiales- 2662 species Tricogyne 4. Gigartinales- 880 species Carpogonium 5. Corallinales- 725 species Carpogonial branch 1N female gametophyte 2N carposporophyte on 14 1N female gametophyte 1 3.Class: Florideophyceae 3.Class: Florideophyceae 2. Order Rhodomeniales Auxiliary cell formed before fertilization 1.Order Nemaliales Auxiliary branch & carpogonial branch arise Genus: Cumagloia from same supporting cell Gominoblast initiated from a fused carpogonium & auxiliary cell - cylindrical with branchlets -multiaxial Spermatium - saxicolous 2N carpospores - intertidal Carpogonium on goniblimoblast filaments Carpogonial branch S A S Auxiliary Cell Supporting Cell 2N carposporophyte on 1N female gametophyte 1N female gametophyte 3.Class: Florideophyceae 3.Class: Florideophyceae 2. OrderRhodomeniales 2. Order Rhodomeniales Genus: Rhodomenia Genus: Botryocladia -Subtidal, saxicolous - Mucus-filled sacs -Multiaxial - “sea grapes” -Subtidal, saxicolous - Associated with juvenile fish - Dichotomous branching -Multiaxial 2 3. Class: Florideophyceae 3.Class: Florideophyceae 3. Order: Ceramiales Auxiliary cell develops from supporting cell of 3. Order Ceramiales Genus: Ceramium carpogonial branch after fertilization Genus Polysiphonia Ooblast filament forms between carpogonium & auxiliary cell Gominoblast initiated from axiliary cell Spermatium After Tricogyne fertilization Carpogonium Carpogonial Branch - Prominent trichoblasts S S A S A which leave scars after they fall off. Ooblast filament - Number of pericentral Supporting cell trasfers 2N carpospores cells helps to identify to zygote nucleus on gonimoblast filaments species 1N female gametophyte 2N carposporophyte on 1N female gametophyte -Polysiphonous 3. Class: Florideophyceae 3.Class: florideophyceae 3. Order: Ceramiales 3. Order Ceramiales Genus: Ceramium Genus Microcladia - saxicolous or epiphytic - fully corticated -distichous -uniaxial - saxicolous or ephiphytic alternate - fully or partially corticated -uniaxial pectinate 3 3.Class: Florideophyceae 3.Class: Florideophyceae 4. Order Gigartinales 4. Order Gigartinales Genus Mazzaella Auxiliary cell present BEFORE fertilization but on a distant branch Ooblast filament transfers zygote nucleus to auxiliary cell Gominoblast initiated from auxiliary cell Common local species: •M. flaccida – yellow/green; mid to upper intertidal •M. splendens – red/purple; low intertidal Spermatium Iridescence • Proteinaceous cuticle • Multiple layers Ooblast filament • Alternating opaque and translucent layers trasfers • Layering produces light interference zygote nucleus patterns that give iridescent appearance when submerged Supporting A A • Adaptive advantage unknown Cell 2N carpospores Auxiliary on Cell gonimoblast filaments 2N carposporophyte on 1N female gametophyte 1N female gametophyte 3.Class: Florideophyceae 3.Class: Florideophyceae 4. Order Gigartinales 4. Order Gigartinales Genus Mazzaella Genus Mastocarpus species complex 2N carposporophytes on female gametophyte 1N gametophytes -multiaxial - filamentous medulla 2N tetrasporophyte Gametophyte Carposporophyte Tetrasporophyte 4 3. Class: Florideophyceae 3.Class: Florideophyceae 4. Order: Gigartinales 4. Order Gigartinales Genus: Constantinea Genus Endocladia -uniaxial - thallus covered with bumps (antiherbivory) - very high intertidal - saxicolous - cup and - can facilitate recruitment saucer algae of other algae (Fucoids) - intertidal to subtidal Other spp in Gigartinales are important for carageenan production 3. Class: Florideophyceae 3. Class: Florideophyceae 5. Order: Corallinales 5. Order: Corallinales • Isomorphic alternation of generations • Reproductive structures in conceptacles • Fossils from 500 million years ago • Cell walls impregnated with CaCO3 • A crustose coralline alga in AK is (i(anti-hbiherbivory) ~700 years old – oldest alga known • More calcified red algae than any on earth?!! other algae • Ecological importance: stabilize reefs, induce invert settlement • Especially sensitive to desiccation – occur IN tidepools (not nearby surfaces) 5 How do coralline algae become calcified? Coralline Algae and Global Warming What is known: Carbon reaction in seawater: • Sequestering of Calcium ions from the water column, synthesis 2 of calcium carbonate (CaC03) into cell wall CO2 + H20 H2C03 HCO3 + H+ CO3 + H+ • Synthesis of calcium carbonate (precipitation) requires high Carbonic acid Bicarbonate Carbonate pH (basic/alkaline) •Higgfpyh rates of photosynthesis correlate with hig gfh rates of more acidicIncreasing CO2 more basic pushes RXN in this calcification direction • Photosynthesis may raise the pH immediately outside cells • Calcification is 10x faster in the light than the dark • Global warming likely to lead to a lower in pH (raise in acidity of the world’s oceans • Highest in young tissue (growth at apices and intergenicula) • Acidic environment is bad for calcification process big (complicated) trouble for calcified critters and algae!! • Lots of current research on this 3. Class: Florideophyceae Geniculate corallines 5. Order: Corallinales Geniculum Supporting cell acts as an auxiliary cell (flexible joint) Carpogonial branches located in conceptacles •upright Gominoblast initiated from a fusion of cells in carpogonial branch •articulated Intergeniculum (hard part between genicula) 2N carpospores on gonimoblast Spermatium filaments Supporting Non-geniculate corallines Cell Crustose or Unattached Encrusting Branching Carpogonial Branch Tricogyne Carpogonium 2N carposporophyte on 1N female gametophyte 1N female gametophyte 6 3. Class: Florideophyceae 3. Class: Florideophyceae 5. Order: Corallinales 5. Order: Corallinales Genus Bossiella Genera Corallina - Common intertidaly - Intergenicula - Common intertidally typically “heart- -Conceppptacles on tips shaped” -Finely branched, more so than Bossiella or - Conceptacles in pairs Calliarthron on the face of a - Intergenicula are thin segment, not margins and tubular and smaller than those on Bossiella - Intergenicula are or Calliarthron larger than Corallina 3.Class: florideophyceae-6767 species 3. Class: Florideophyceae 5. Order Corallinales- 725 species 5. Order: Corallinales Genus Caliarthron Genus Lithothamnion •rhodolith •unattached -Common intertidally • free-living • non- geniculate form -Inngnuypytergenicula typically • biogenic habitat for lots of inverts! “wingnut-shaped” - Conceptacles mainly on margins of segments - Calcareous sections are larger than Corallina 7 Distributional Limits World Rhodolith Distribution •Depth -light limited in deep, dessicated in shallows •Water motion-need intermediate amount of hydraulic energy •Sedimentation -smothered by fine sediments DISTURBANCE low high Rhodolith Beds New Report Foster 2001 buried by ‘intact’ ‘reduced’ sand siltation rhodolith size, cover bed Biogenic Ecosystems – Foundation Species Rhodolith beds, reefs that rock and roll Kelp Forests Coral Reefs Seagrass Meadows Rhodolith Beds 8 What are other important features of rhodolith beds? Rhodolith Bed Community Form complex habitat for a Cryptofauna/Infauna Epifauna/Epiflora variety of orgamisms Cover extensive ares of • hard bottom species the seafloor, globally • soft bottom species distributed Seasonal Macroalgal Species Halymenia hollenbergii Scinaia confusa Sporochnus bolleanus Kallymenia pertursa 9 Growth Rate Internal Banding L. muellerii 0.6 mm/yr L. margaritae 5.6 mm/yr S. trichotomum 7-8 mm/yr New Catalina rhodoliths growth 1.6 mm/yr Coralline algae as global palaeothermometers Baja California Banding reflects sea surface temperature signal using SrCO3 and MCOMgCO3 They are found in Pleistocene and Pleiocene fossil deposits Lithothamnion glaciale Kamenos et al. 2008 10 Post-fertilization in a nutshell auxiliary cell? Yes No Nemaliales – Gonimoblasts from carpegonium Before After Corallinales – Ceramiales – Fusion of Ooblast? (has ooblast) Yes. Gigartinales – carpegonium with Auxiliary cell is anywhere carpegonial in thallus branch * Supporting cell acts No. Rhodymeniales – as auxiliary cell Fusion with carpegonium 11.