By Lin Yuan-Shao Cao Wen-Qing Guo Dong-Hui Wu Li-Sheng (Dept. of Oceanography, XMU)

1. Chapter 15 Horizontal distribution (Geographic distribution) By Lin Yuan-Shao Cao Wen-Qing Guo Dong-Hui Wu Li-Sheng (Dept. of Oceanography, XMU)

2. Some terms and definition • Dominant species（优势种）：生态系或群落中，数量多、出现频率高的物种。 • Common species（习见种）：群落中分布广、但数量不是很多的种类。 • Locally abundant species（局限种）：局限分布于某一海域或地区的种类。 • Uncommon species（少见种）：群落中少见的种类。 • Rare species（稀有种）：海域或群落中数量稀少，分布窄的种类 根据海域或群落中生物的数量等级和出现频率划分５级，如上。

3. Cold water species（冷水种）：生殖、生长最适温度低于４℃，自然分布区月平均水温<10℃的生物；包括寒带种（适温0℃左右）和亚寒带种（适温0-4℃） • Cold zone species（寒带种） • Subcold zone species（亚寒带种） • Temperate water species（温水种）：生殖、生长最适温度4-20℃，自然分布月平均水温10-15℃；包括冷温带种（4-10℃）和暖温带种（10-20℃）。 • Cold temperate species（冷温带种） • Warm temperate species（暖温带种） • Warm water species（暖水种）：生殖、生长适温>20℃，自然分布区月平均水温>15 ℃的种类；包括亚热带种（适温20-25℃）和热带种（适温>25℃） • Subtropical species（亚热带种） • Tropical species（热带种）

4. Native species（本地种） • Immigrant species（迁入种） • Exotic species（外地种） • Cosmopolitan species（世界种）：广温广盐性生物，能分布于世界各海域。 • Littoral organisms（沿岸生物） • Indicate organisms (bio-indicator)

5. Eurybathic organisms Euryhaline Eurytherm Reproductive eurythermy Vegetative eurythermy Stenobathic organisms Stenohaline Stenotherm Reproductive stenothermy Vegetative stenothermy

6. Tropical submergence（热带深潜）：某些广深性冷水种生物，能分布在南、北两半球冷水水域，同时也能通过赤道深层水域，而呈现南、北两半球的连续分布。 • Bipolarity（两极同源）：也称两极分布（bipolar distribution). 海洋生物的一种分布隔离现象。一个动物的种或类群同时分布在南北两半球海洋的某一区域内，而不分布在中间的热带海洋。如Calanus helgolandicus〕同时分布在北大西洋和新西兰的海洋中。 • Discontinuous distribution（隔离分布）：一个物种或类群的分布区不是连续的，它们的分布区有2个或几个相距很远的地区或水域所组成，中间地区没有该种或该类群生物的存在。这种分布状态称为隔离分布。导致隔离分布往往是由于环境的温度、盐度所引起的；此外，海底地貌的也是导致隔离分布的原因之一。 • Geographic isolation（地理隔离）：由地理障碍，入开阔海洋、河口或其它因子所产生的对生物分布的隔离。 • Vegetative distribution（营养分布）：某些生物的分布区超过其适于生殖的分布区，在不宜生殖的分布区的种群，必须不断地从外界移入成体或幼体。生物在这种分布区的分布称为营养分布，也称不妊分布（sterile distribution）

7. §15.1Some concepts: • Fertilregion • Sterilregion sterile distribution

8. §15.2bipolarity Topical submergence

11. cosmopolitanism • Eurytherm cosmopolitan represent species: 锥体浅室水母(siphonophore), Beroe cucumis (ctenophore), and Oithona similis(copepoda) , etc. • Stenotherm cosmopolitan: Calanus finmarchicus (copepoda), Dimophyes arctica (siphonophore), and Themisto comressa (Amphipoda), etc.

12. §15.3Geographic distribution of plankton

13. (Ⅰ) relationship between horizontal distribution and temperature 1、plankton in frigid zone:（<0－5℃） • arctic plankton:eg. Ceratium arcticum, Cyanea capillata, Calanus glacialis, 北极箭虫, and Spiratella retroversa. • antarctic plankton: eg. Rhincalanus gigas, Euphausia superba, 南极海天使、Fritillaria autarctica. 2.Plankton in temperate zone: distribution in warm sea(5-20 ℃), various species. 3.Plankton in tropic zone：distribution in tropic sea（25－35℃） • e.g. Porpita porpita, Velella velella, and Physalia physalia; Ocyropsis crystallina, Cestum veneris (Ctenophora); Undinula spp., Sapphirina spp., and Copilia spp. (copepoda); Sagitta crassa (Chaetognatha); Pyrosoma (Tunicata). 4. Plankton in subtropics

14. （Ⅱ） Relationship between horizontal distribution and saltness 1) Pelagic plankton: inhabitation in sea region with higher saltness Velella velella, Physalia physalia, Sagitta hexaptera, Euphausia pasifica, and Pyrosoma (Tunicata). 2) Inshore plankton: inhabitation in sea region with lower saltness • Chaetocera affinis (Diatom),Hemiaulus sinensis; Noctiluca scientillans . • Tintinnopsis spp. (Tintinnida) • Labidocera euchaeta, Centropages mcmurrichi, Acartia spinicauda (copepoda) • Pseudeuphausia sinica, Acetes chinensis • Sagitta bedoti (Chaetognatha) • marine cladocerans, planktonic larvae 3) Estuarine plankton: inhabitation in estuary with lower saltness • Pseudodiaptomus spp., Eurytemora spp., Schmackeria spp.; rotifer

15. （Ⅲ）Relationship between horizontal distribution and ocean current • Indicator species of warm current • Indicator species of cold current

16. §15.4 Plankton in China sea

17. A) Plankton in Bohai Bohai is a inland sea that half close, and it is quite influenced by the mainland weather. The annual variation of Water temperatureis very wide (the range of variation > 25 ℃). The saltness is lower, and usually under 30.

18. In Bohai, the ecological characters of plankton are eurythermal and with low saltness Representative species of phytoplankton: Chaetocera affinis, Skeletonema costatum; Dominant species of zooplankton: Sagitta crassa, Labidocera euchaeta, Calanus sinicus In addition, some estuarine or inshore species, such as Acetes chinensis, could also dominate somtimes.

19. B) Plankton in Yellow sea Yellow sea is also a half closed sea, and the conditions of hydrology is quite complicated, mainly influenced by the littoral dilute water, middle water with low temperature and high salinity, and warm current in southeast intruded from South China sea.

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21. Characters of planktonic distribution in Yellow Sea: （1）Littoral plankton The main species of phytoplankton are Ditylum brightwellii, Hemiaulus sinensis; the dominant species of zooplankton are Sagitta crassa, Acartia clausi, Paracalanus parvus, and Calanus sinicus. （2）Middle plankton The main species of phytoplankton are Rhizosolenia (长栓) and薄壁半管藻; the dominant species of zooplankton are Calanus sinicus, Euphausia pacifica, and Themisto gracilipes. （3）Southeast plankton In winter and spring, the water with low-temperature and high-saltness is dominant, and the plankton is similar to middle plankton. In summer and autumn, some warm-water species come into this region, e.g. Planktoniella sol, sagitta enflata, Undinula darwinii, because of Yellow Sea Warm Current strengthening.

22. C) Plankton in East China sea • The composition of planktonic species is influenced by the interactive effect of the Changjiang River runoff, the continental littoral current, Kuroshio system, and Yellow Sea Cold Water Mass southbound from south of Yellow sea.

24. Characters of plankton in East China sea • Littoral: Such as Skeletonema costatum, Ditylum brightwellii, Calanus sinicus, Euchaeta concinna, Pseudeuphausia sinica,and Schmackeria poplesia. • Pelagic sea: a)East of 124°E in East China sea, and Taiwan warm current flow cross there.There are mainly warm-water species, e.g.,planktoniella sol and Sagitta enflata; b) Waters of Taiwan strait, offcoast of Fujian. It is influenced by the interactive effect of the Kuroshio branch, the littoral current from East China sea, and South China Warm Current. The composition of species varys with current system.

25. D) Plankton in South China sea • The littoral plankton are such as Stephanopyxis palmeriana, Lucifer hanseni, and Lucifer intermedicus

27. E) Plankton in east of Taiwan • The waters in east of Taiwan belongs to west pacific, and the main current of Kuroshio flow across there. The hydrologic features are comparatively stable, and the planktonic fauna is tropical.

29. §15.5 Indicators of ocean current • Significance • Characters • The indicators of warm current， such as Velella velella,Physalia physalia, Cestum veneris, Pyrosoma spp., • The indicaors of cold current, such as Cyanea capillata, Calanus glacialis