著者

天野 光孝 加戸 隆介 橘高 二郎

出版者

The Sessile Organisms Society of Japan

雑誌

付着生物研究 (ISSN:03883531)

巻号頁・発行日

vol.5, no.2, pp.7-12, 1985-03-20 (Released:2009-10-09)

参考文献数

7

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A leaflike shrimp Nebalia sp., which belongs to the most primitive genus of Malacostraca, has been found abundantly at the base of Bryopsis sp. growing in an outdoor concrete tank used for Homarus culture at Sanriku. The species is considered to be desirable as a living food organism for larval rearing because of its suitable size and tolerance to deterioration of the bottom condition.Sampling was done in the pond from July to December of 1983. Water temperature ranged from 22.3°C in summer to 4.5°C in winter. The animals were found throughout the season with the highest occurrence of egg-bearing females in October. The larvae were reared successfully at water temperature between 15°C to 25°C in combination with the salinity between 20‰ to 33‰ under the continuous darkness. The larvae showed the best growth at 25°C in combination with 33‰. The most effective food for the larval rearing in the laboratory was the fine particles of the dried food as shrimp pellet and krill.The larvae hatched out as adult form. Number of segments in the flagellum branches of the first antenna and the second antenna increased from 3:3, expressed as segmentation formula, at I stage to 4:3, 5:4, 6:5, 7:6 and 8:7 at II, III, IV, V and VI stages, respectively. After VII stage, the increase became irregular.

著者

難波 信由 佐藤 新 小河 久朗 加戸 隆介

出版者

日本付着生物学会

雑誌

Sessile organisms (ISSN:13424181)

巻号頁・発行日

vol.25, no.1, pp.17-23, 2008-02-29

被引用文献数

2

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Both intact thalli of <i>Sargassum fusiforme</i> and those without holdfasts were aquacultured in Okirai Bay, Northeast Japan, to establish them as a multi-harvestable aquaculture resource. Elongated main branches (edible part) of the intact thalli were harvested twice (August 2005 and June 2006) during 1.5 years of aquaculture (November 2004-June 2006). However, two fouling organisms, <i>Laminaria japonica</i> and <i>Mytilus galloprovincialis</i>, also occurred on the aquaculture rope. As a fouling countermeasure, <i>S. fusiforme</i> thalli without holdfasts were aquacultured for 6 months (February-August 2005) with freshwater treatment (biweekly 2-min exposures). Their stipes regenerated holdfasts, and the attached holdfasts elongated around the aquaculture rope; moreover, the new holdfasts gave rise to a number of stipes, which became the bases of new main branches. The elongated main branches were harvested after 4 months of aquaculture. Thalli without holdfasts collected from the rope were aquacultured again for ca. 1 year (October 2005-August 2006) with the same freshwater treatment. After 8 months, elongated main branches were harvested from these thalli with their new regenerated holdfasts. The freshwater treatment was effective to remove <i>L. japonica</i>, but it had no effect on fouling by <i>M. galloprovincialis</i>. Therefore, the two successive harvests were conducted before the mass occurrence of <i>M. galloprovincialis</i> in the summer.

著者

加戸 隆介 難波 信由

出版者

北里大学

雑誌

基盤研究(C)

巻号頁・発行日

2004

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1998年の猛暑による影響で脱落した護岸壁潮間帯生物群集の修復を図ることを目的に、岩手県越喜来湾崎浜地区の鬼間ヶ崎側護岸壁を調査対象地点として、チシマフジツボに着目して本研究を3年間行ってきた。結果1.捕食動物の侵入を制限すれば護岸壁の潮間帯生物群集再生可能:対照である護岸壁の現状に大きな変化はなく、3年前と同様に種数も個体数も改善が見られない。一方、チシマフジツボを付着基質とした群集は健在である。ムラサキイガイに被覆されてもチシマフジツボは生き残り、ムラサキイガイ群集の貝殻を付着基質として第2次付着生物(フジツボ類、コケムシ類、海藻類)群集が形成された。これが捕食動物の侵入を制限した場合の潮間帯極相と見られる。昨年秋の荒天によりチシマフジツボを覆っていたムラサキイガイが大きく剥離した。このサイズのチシマフジツボ群集はウニによる捕食を受けにくいため、今後のチシマフジツボの生残はチヂミボラに依存していると言えよう。2007年の初春にチシマフジツボの新たな世代加入があり、初めて2世代が同居できるかに興味が持たれる。2.凹凸を付与は春以前に実施する必要がある:凹凸を付与したコンクリート板は明らかに生物群集を形成・維持しやすいが、管棲多毛類やコケムシ類がこの付着基質に先に付着・被覆した場合には、立体的で複雑な生物群集は発達しにくい。これを考慮すると、複雑な生物群集を形成させるためには、試験基盤設置(将来的には護岸壁処理)を冬に実施し、チシマフジツボの付着を優先させることが望ましい。3.手のかからないキタムラサキウニ排除方法が生物群集再生の決め手:護岸壁潮間帯生物群集の再生には、チシマフジツボの付着と殻径が10mm程度に成長するまで捕食者から保護することが必要である。そのためには、基質表面をウニが匍匐しにくい処理を施すことが決め手であり、次の段階としてその方法を考案することが重要であると考えられた。