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Article: Northward extension of geographic range of the sea urchin Hemicentrotus pulcherrimus in Hokkaido, Japan.
- Article from:
- Journal of Shellfish Research
- Article date:
- August 1, 2007
- Author:
CopyrightCOPYRIGHT 2007 National Shellfisheries Association, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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ABSTRACT In the early 1990s, the geographic range of the sea urchin Hemicentrotus pulcherrimus from the Sea of Japan increased from off southwestern Hokkaido to off northern Hokkaido. This was caused by episodic recruitment in 1989, 1990, and 1991. These recruitments coincided with high water temperature during the larval periods (March to May). In 1993, H. pulcherrimus, at a density of 2.4 individuals/m2 derived from those three year classes, was found at a depth of 2 3 m in Tomari, where it had not been found in 1989. In Oshoro Bay, this sea urchin appeared dramatically in 1990, reached a peak density of 5.3 individuals/[m.sup.2] in 1992, consisting mainly of 1989- and ...