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Sympatric spawning but allopatric distribution of Anguilla japonica and Anguilla marmorata: temperature- and oceanic current-dependent sieving.

Han YS, Yambot AV, Zhang H, Hung CL - PLoS ONE (2012)

Bottom Line: The composition ratio of these 2 eel species showed a significant latitude cline, matching the 24 °C sea surface temperature isotherm in winter.A. marmorata prefer high water temperatures and die at low water temperatures.In contrast, A. japonica can endure low water temperatures, but their recruitment is inhibited by high water temperatures.

View Article: PubMed Central - PubMed

Affiliation: Institute of Fisheries Science, College of Life Science, National Taiwan University, Taipei, Taiwan. yshan@ntu.edu.tw

ABSTRACT
Anguilla japonica and Anguilla marmorata share overlapping spawning sites, similar drifting routes, and comparable larval durations. However, they exhibit allopatric geographical distributions in East Asia. To clarify this ecological discrepancy, glass eels from estuaries in Taiwan, the Philippines, Indonesia, and China were collected monthly, and the survival rate of A. marmorata under varying water salinities and temperatures was examined. The composition ratio of these 2 eel species showed a significant latitude cline, matching the 24 °C sea surface temperature isotherm in winter. Both species had opposing temperature preferences for recruitment. A. marmorata prefer high water temperatures and die at low water temperatures. In contrast, A. japonica can endure low water temperatures, but their recruitment is inhibited by high water temperatures. Thus, A. japonica glass eels, which mainly spawn in summer, are preferably recruited to Taiwan, China, Korea, and Japan by the Kuroshio and its branch waters in winter. Meanwhile, A. marmorata glass eels, which spawn throughout the year, are mostly screened out in East Asia in areas with low-temperature coastal waters in winter. During summer, the strong northward currents from the South China Sea and Changjiang River discharge markedly block the Kuroshio invasion and thus restrict the approach of A. marmorata glass eels to the coasts of China and Korea. The differences in the preferences of the recruitment temperature for glass eels combined with the availability of oceanic currents shape the real geographic distribution of Anguilla japonica and Anguilla marmorata, making them "temperate" and "tropical" eels, respectively.

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Map showing the mean SST images of the East Asian continental shelf in summer (July 2009) (A) and winter (January 2010) (B).The image was obtained using the National Oceanic and Atmospheric Administration AVHRR sensor data.
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pone-0037484-g003: Map showing the mean SST images of the East Asian continental shelf in summer (July 2009) (A) and winter (January 2010) (B).The image was obtained using the National Oceanic and Atmospheric Administration AVHRR sensor data.

Mentions: The mean SST of East Asian coastal waters in summer (July 2009) and winter (January 2010) are shown in Fig. 3. During summer, the mean SST was >24°C in all areas except the Japan Sea (Fig. 3A). However, in winter, when the warm Kuroshio waters flow northward and the cold coastal waters flow southward, clear temperature fronts exist on the continental shelf of East Asia. The SST around northern Luzon Island was high (>25°C) in winter but <20°C on the coast of Southern China and Pacific coast of Japan and <15°C on the southern coast of Korea and central coast of China. SST was usually <5°C north of the Changjiang River in China and on the western coast of Korea (Fig. 3B). In the coastal waters around Taiwan, the mean SST in winter was higher in southeast sites (>24°C) than in northwest sites (<20°C), forming a clear temperature front (Fig. 3B).


Sympatric spawning but allopatric distribution of Anguilla japonica and Anguilla marmorata: temperature- and oceanic current-dependent sieving.

Han YS, Yambot AV, Zhang H, Hung CL - PLoS ONE (2012)

Map showing the mean SST images of the East Asian continental shelf in summer (July 2009) (A) and winter (January 2010) (B).The image was obtained using the National Oceanic and Atmospheric Administration AVHRR sensor data.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3366981&req=5

pone-0037484-g003: Map showing the mean SST images of the East Asian continental shelf in summer (July 2009) (A) and winter (January 2010) (B).The image was obtained using the National Oceanic and Atmospheric Administration AVHRR sensor data.
Mentions: The mean SST of East Asian coastal waters in summer (July 2009) and winter (January 2010) are shown in Fig. 3. During summer, the mean SST was >24°C in all areas except the Japan Sea (Fig. 3A). However, in winter, when the warm Kuroshio waters flow northward and the cold coastal waters flow southward, clear temperature fronts exist on the continental shelf of East Asia. The SST around northern Luzon Island was high (>25°C) in winter but <20°C on the coast of Southern China and Pacific coast of Japan and <15°C on the southern coast of Korea and central coast of China. SST was usually <5°C north of the Changjiang River in China and on the western coast of Korea (Fig. 3B). In the coastal waters around Taiwan, the mean SST in winter was higher in southeast sites (>24°C) than in northwest sites (<20°C), forming a clear temperature front (Fig. 3B).

Bottom Line: The composition ratio of these 2 eel species showed a significant latitude cline, matching the 24 °C sea surface temperature isotherm in winter.A. marmorata prefer high water temperatures and die at low water temperatures.In contrast, A. japonica can endure low water temperatures, but their recruitment is inhibited by high water temperatures.

View Article: PubMed Central - PubMed

Affiliation: Institute of Fisheries Science, College of Life Science, National Taiwan University, Taipei, Taiwan. yshan@ntu.edu.tw

ABSTRACT
Anguilla japonica and Anguilla marmorata share overlapping spawning sites, similar drifting routes, and comparable larval durations. However, they exhibit allopatric geographical distributions in East Asia. To clarify this ecological discrepancy, glass eels from estuaries in Taiwan, the Philippines, Indonesia, and China were collected monthly, and the survival rate of A. marmorata under varying water salinities and temperatures was examined. The composition ratio of these 2 eel species showed a significant latitude cline, matching the 24 °C sea surface temperature isotherm in winter. Both species had opposing temperature preferences for recruitment. A. marmorata prefer high water temperatures and die at low water temperatures. In contrast, A. japonica can endure low water temperatures, but their recruitment is inhibited by high water temperatures. Thus, A. japonica glass eels, which mainly spawn in summer, are preferably recruited to Taiwan, China, Korea, and Japan by the Kuroshio and its branch waters in winter. Meanwhile, A. marmorata glass eels, which spawn throughout the year, are mostly screened out in East Asia in areas with low-temperature coastal waters in winter. During summer, the strong northward currents from the South China Sea and Changjiang River discharge markedly block the Kuroshio invasion and thus restrict the approach of A. marmorata glass eels to the coasts of China and Korea. The differences in the preferences of the recruitment temperature for glass eels combined with the availability of oceanic currents shape the real geographic distribution of Anguilla japonica and Anguilla marmorata, making them "temperate" and "tropical" eels, respectively.

Show MeSH