하구 및 연안생태학 Estuarine and coastal ecology

2010 년 11월 2 계절적 변동

• 빛과 영양염분의 조건에 따라

• 봄 가을 대발생 계절적 변동 Sverdrup 에 의한 대발생 모델

• Compensation depth (보상심도)

• Critical depth (임계수심) Sverdrup 에 의한 대발생 모델

홍재상외, 해양생물학 Sverdrup 에 의한 대발생 모델

봄 여름 가을 겨울 수심

혼합수심 임계수심 (mixed layer depth) (critical depth) Sverdrup 에 의한 대발생 모델

봄 여름 가을 겨울 수심

혼합수심 임계수심 (mixed layer depth) (critical depth) Diatoms (규조류)

• Bacillariophyceae (1 fragment of centrics, 19 fragments of pennates in Devonian marble in Poland Kwiecinska & Sieminska 1974) Diatoms (규조류)

• Bacillariophyceae • Temperate and high latitude (everywhere) Motility: present in pennate diatoms with a raphe (and male gametes)

Resting cells (spores): heavily silicified, often with spines (Î보충설명) Biotopes: marine and freshwater, plankton, benthos, epiphytic, epizooic (e.g., on whales, crustaceans) endozoic, endophytic, discolouration of arctic and Antarctic sea ice Snow Algae (규조류 아님) Snow algae describes cold-tolerant algae and cyanobacteria that grow on snow and ice during alpine and polar summers. Visible algae blooms may be called red snow or watermelon snow. These extremophilic organisms are studied to understand the glacial ecosystem. Snow algae have been described in the Arctic, on Arctic sea ice, and in Greenland, the Antarctic, Alaska, the west coast, east coast, and continental divide of North America, the Himalayas, Japan, New Guinea, Europe (Alps, Scandinavia and Carpathians), China, Patagonia, Chile, and the South Orkney Islands. Diatoms (규조류)

• Bacillariophyceae • Temperate and high latitude (everywhere) • 2~1000 um • siliceous frustules • Various patterns in frustule Centric vs Pennate Centric diatom Pennete small discoid plastid large plate plastid Navicula sp.

Tube-dwelling diatoms

Parlibellus sp.

Selected Diatom Genera Thalassiosira (Gr. thalassios, belongs to the sea + Gr. seira, thread): occurs as cells in chains or embedded in mucilage. Cells in chains are linked by threads extending from strutted processes.

The genus Thalassiosira was first described by Cleve 1873.

Characters used for identification:

-Shape of frustule in girdle view. -Thickness and length of connecting threads. -Valve processes: number and location of rimoportulae (labiate processes); -number and arrangement of fulto- portulae; number of marginal rings of rimoportulae; distance between the marginal processes; presence /absence of scattered rimoportulae. Note: internal view of the valve showing rimoportulae

Note: the fultoportulae (eg. Star-shaped structures) Valve Processes

Portules: tubes passing through the valves (Left) Fultoportulae: confined to the centric order Thalassiosirales. A tube which passes through the valve and is supported by two or more buttresses.

(Right) Rimoportulae: widespread throughout diatom genera. A tube similar to strutted processes but without the satellite pores. Arrangements thought to be species- specific. Function is less clear, thought to be associated with mucilage production. Chaetoceros (Gr. chaite, long hair + Gr. keros, horn): found as chains of cells attached by intercalary setae extending from adjacent cells and touching one another near their point of origin. Processes: Setae - hollow outgrowths of the valve that project beyond the valve margin. Characters used for identification:

Chloroplasts: number, shape, size, presence or absence in setae. Two major orders: Phaeoceros ~ have chloroplasts in the setae. Hyalochaete ~ do not have chloroplasts in the setae.

Setae: Coarseness (thickness, spines) direction Terminal setae different from others in shape and thickness Terminal setae direction Adjacent setae fused One seta longer than the three others Crossing of the setae

Direction of the chain Rhizosolenia (Gr. rhiza, root + Gr. solen, canal): exists as single cells or chains. Valves are ornamented with a spine that is open at the tip and extends into the interior as a rimoportula. Note the extremely long girdle with multiple cingular bands.

Note: nitrogen fixation occurs via cyanobacteria endosymbionts in select species Characters used for identification:

Valve shape Process: location straight or curved with or without wings shape of distal end

**A taxonomy revision in 1986 has separated this existing group into Rhizosolenia, Pseudosolenia, and Probosica.

Naviculoid diatoms: note epivalve (E) epicingulum containing 4 bands (EC) Navicula is probably the incomplete hypocingulum (HC) and the most species-rich hypovalve (H). of all diatom genera, with nearly 2000 A characteristic feature of many pennate widely accepted genera is the presence of one or two species. longitudinal slits through the valve. In most cases there are two raphe slits, Common to sea ice. arranged end-to-end along or near the midline of the valve. Nitzchia (named for Christian Ludwig Nitzsch, a German naturalist): cells are linear in both valve and girdle view. A marginal raphe occurs on both valves, and on the same side of the frustule.

Characters used for identification: Colony type; Valve outline; Presence of a central nodule; Ratio of between numbers of fibulae and transapical costae. Dinoflagellates Special features: mass occurrences (red tides), toxicity, bioluminescence, vertical migration Dinoflagellates

(Silurian specimens questioned but generally accepted. A gap of 150 to 200 my in between this and the next fossil record is also troublesome. In the taxonomy of dinoflagellates the cell covering, or theca, provides the most useful descriptive characters.

1. The theca is clearly responsible for the shape of the cell, which gives the broad classification. 2. In armoured dinoflagellates the main part of the theca consists of cellulosic plates. 3. The number, shape, arrangement, and ornamentation of the plates provide features for finer taxonomic separation. Armored or thecate dinoflagellates: each of the thecal vesicles contain a thecal plate composed of cellulose.

Unarmored or Naked dinoflagellates: the thecal vesicles are devoid or nearly devoid of contents. Several dinoflagellates are capable of producing internal siliceous structures. These pentasters are geologically important.

Motility: present in flagellated forms

Resting cells (cysts): thick walled, often with spines Motility: present in flagellated forms

Resting cells (cysts): thick walled, often with spines

Biotopes: marine and freshwater, plankton, littoral (sandy beaches, 산호, 말미잘, 그리고 대형 조개류의 조직에 공생체 Selected Dinoflagellate Genera

Oxytoxum: common marine form, heterotrophic. A component of the microzooplankton grazing assemblage Prorocentrum: a common desmokont dinoflagellate. Theca composed of two halves, more or less flattened, so that the cells appear narrow in edge view and spherical or oval in valve view.

One of the most common and variant species in the genus. Cosmopolitan in cold temperate to tropical waters. Can tolerate salinities above 90 PSU. Desmokont: a dinoflagellate cell type in which two dissimilar flagella emerge from the anterior part of the cell.

Dinokont: a dinoflagellate cell type in which two dissimilar flagella are inserted vertically; one flagellum is transverse and housed in a cingulum (= girdle) and the other is longitudinal and housed in a sulcus. The transverse flagellum provides propulsion and the longitudinal flagellum provides direction.