No.73 (March,2008)
No.73 (March,2008)
A－415 Toshihiro MIZUSHIMA
Characteristics of reproductive ecology of the Pandalid shrimps around Hokkaido（Review)
Eight species of the protandrous hermaphroditic Pandalid shrimps inhabit the periphery of Hokkaido, Japan.
Coastal species, such as P. pacifica, are mostly small in size and mainly distributed in eelgrass beds in shallow waters less than 10 m in depth, with lower egg production and a short planktonic larval period. Offshore species, including P. eous and P. hypsinotus, are larger in size, inhabit only deep sea and have a long planktonic larval period, and their egg production is high. P. coccinata, a mesostomate type which inhabits the deep sea, has a large body and is known especially for its large-size eggs, lower egg production, and an immediate shift to benthic life. Relevance between these reproductive characteristics and the reproduction of Pandalid shrimps was examined.
Eight species of the protandrous hermaphroditic Pandalid shrimps inhabit the periphery of Hokkaido, Japan.
Coastal species, such as P. pacifica, are mostly small in size and mainly distributed in eelgrass beds in shallow waters less than 10 m in depth, with lower egg production and a short planktonic larval period. Offshore species, including P. eous and P. hypsinotus, are larger in size, inhabit only deep sea and have a long planktonic larval period, and their egg production is high. P. coccinata, a mesostomate type which inhabits the deep sea, has a large body and is known especially for its large-size eggs, lower egg production, and an immediate shift to benthic life. Relevance between these reproductive characteristics and the reproduction of Pandalid shrimps was examined.
A－416 Hiroya OKUMURA
Study of the effeciental cultivation of marine microalge on mass algae cultivation system for mariculture breeding
In Mariculture, micro-alga is necessary to use breeding for shellfish. It is difficult to cultivate mass volume chamber under artificial luminair in marine-micro-algae. A lot of type cultivation systems were made to mass production of foods for men or another. Popularly a kind of alga Chlorella was produced in fresh water under Sun light. We made a mass production system for micro-algae using artificial luminair. It was possible to controll at water temperature, air flow and light intensity in luminair, and have a 200L chamber (artemia hatching jar) in this system.
In first section, we described component of mass algae cultivation system and light environment of chamber fulled sea water or cultured sea water. Air condition was exminated Pavliva lutheri（Droop）Green culture in several inflow conditions and babble size conditions, it was basically factor in cultivation. Optic value was found then. Espeally, According to change inflow of air, maximum cell density was changed. It indicated mixture of the chamber relate to a factor of cultivation condition.
In second section, we described to response maximum cell density to light intensity condition, and to appear special characteristic of chamber in algae cultivation. In high light intensity irradiation, it was not occurred light inhabitation at low cell density. Maximum cell density was as higher as light intensity irradiation. It suggested higher maximum cell density was necessary to irradiate higher light intensity. But cell growth ratio was not changed in each light intensity conditions. It would saturate photosynthesis in each light intensity conditions. Then it suggested cell growth ratio was not related to light intensity condition.
In third section, we simulated light environment in the chamber to reduce to light intensity at luminair during cultiured period and optimized to the PPFD (Phtosynthesis Photon Flux Density) in luminair according to increace cell density. Using light absorbtion ratio of micro-alga in several cell densities, shape of chamber and light intensity of luminair, we surpposed suitable cell density of effeciental production with chamber. It was contributed to cut off the cultivation costs.
In fourth section, we tried to culture P.lutheri under variable light intensity condition, light intensity condition in luminair was changed with cell density and cultivation period. It was possible to reduce cultivation costs of light for changing light intensity with cell density or cultivation period, and to suggest significance methods of cost reduction on mass algae cultivation system. And it proved to be estimation of light environment in the chamber.
In fifth section, we examined to culture micro-alga under 4 kinds of flouresent lamps (red, blue, green and white) to investigate effeciental luminair in mass algae cultivation system. Cell growth ratio was change each examinations using each lamps pairs, fastest cell growth ratio was obtained the examination in red and blue lamp pair. It was possible to reduce the cultivation priod and achieve more effeciental mass algae caltivation. We suggested more avarable guidline to produce is using additive of carbon dioxcide through inflow of air.
In Mariculture, micro-alga is necessary to use breeding for shellfish. It is difficult to cultivate mass volume chamber under artificial luminair in marine-micro-algae. A lot of type cultivation systems were made to mass production of foods for men or another. Popularly a kind of alga Chlorella was produced in fresh water under Sun light. We made a mass production system for micro-algae using artificial luminair. It was possible to controll at water temperature, air flow and light intensity in luminair, and have a 200L chamber (artemia hatching jar) in this system.
In first section, we described component of mass algae cultivation system and light environment of chamber fulled sea water or cultured sea water. Air condition was exminated Pavliva lutheri（Droop）Green culture in several inflow conditions and babble size conditions, it was basically factor in cultivation. Optic value was found then. Espeally, According to change inflow of air, maximum cell density was changed. It indicated mixture of the chamber relate to a factor of cultivation condition.
In second section, we described to response maximum cell density to light intensity condition, and to appear special characteristic of chamber in algae cultivation. In high light intensity irradiation, it was not occurred light inhabitation at low cell density. Maximum cell density was as higher as light intensity irradiation. It suggested higher maximum cell density was necessary to irradiate higher light intensity. But cell growth ratio was not changed in each light intensity conditions. It would saturate photosynthesis in each light intensity conditions. Then it suggested cell growth ratio was not related to light intensity condition.
In third section, we simulated light environment in the chamber to reduce to light intensity at luminair during cultiured period and optimized to the PPFD (Phtosynthesis Photon Flux Density) in luminair according to increace cell density. Using light absorbtion ratio of micro-alga in several cell densities, shape of chamber and light intensity of luminair, we surpposed suitable cell density of effeciental production with chamber. It was contributed to cut off the cultivation costs.
In fourth section, we tried to culture P.lutheri under variable light intensity condition, light intensity condition in luminair was changed with cell density and cultivation period. It was possible to reduce cultivation costs of light for changing light intensity with cell density or cultivation period, and to suggest significance methods of cost reduction on mass algae cultivation system. And it proved to be estimation of light environment in the chamber.
In fifth section, we examined to culture micro-alga under 4 kinds of flouresent lamps (red, blue, green and white) to investigate effeciental luminair in mass algae cultivation system. Cell growth ratio was change each examinations using each lamps pairs, fastest cell growth ratio was obtained the examination in red and blue lamp pair. It was possible to reduce the cultivation priod and achieve more effeciental mass algae caltivation. We suggested more avarable guidline to produce is using additive of carbon dioxcide through inflow of air.
A－417 Akira MIYAZONO and Hiroya OKUMURA
Horizontal distribution of acid vapor sulfur (AVS-S) in the bottom surface mud off Funka Bay, 2006.
Horizontal distributions of acid vapor sulfur (AVS-S) in the bottom surface mud off Funka Bay were investigated in September, 2006. The high AVS-S concentrations (>0.2 mg-S/g-dry mud) were observed in 70-90 m depth area in the inner part of the bay, where the concentrations of organic matter were high (ignition loss >9%). Expansion of the mud had high AVS-S and high ignition loss observed in this study was smaller than in 1979 observation. These results are contradictory to the hypothesis proposed by Maeda et al. ( 2005) that the excess culture of scallops is making worse of mud condition in Funka Bay.
Horizontal distributions of acid vapor sulfur (AVS-S) in the bottom surface mud off Funka Bay were investigated in September, 2006. The high AVS-S concentrations (>0.2 mg-S/g-dry mud) were observed in 70-90 m depth area in the inner part of the bay, where the concentrations of organic matter were high (ignition loss >9%). Expansion of the mud had high AVS-S and high ignition loss observed in this study was smaller than in 1979 observation. These results are contradictory to the hypothesis proposed by Maeda et al. ( 2005) that the excess culture of scallops is making worse of mud condition in Funka Bay.
A－418 Are-Lang CHEN, Hideo YOSHIDA and Yasunori SAKURAI
Reproductive behavior of saffron cod in captivity
The reproductive behavior of saffron cod ( Eleginus gracilis ) was examined in captivity. The captive saffron cod spawned demersal and slightly adhesive eggs, which dispersed and settled on the tank bottom. Ripe males and females did not display the ventral mounting behavior, which displayed in other gadid fishes during spawning. The aggressive behavior such as pushing, prodding and dorsal mounting did not observe between males during the breeding period. The female released all of her ripe eggs in a single spawning. Spawning involved one female and one or more males in bottom of the tank. Just after release of eggs by a female, one or a few males followed the female and spread sperm on the eggs using tail beats. The eggs slowly sank to the bottom.
The spawning behavior of saffron cod was similer to that of Pacific cod, but differed from the single-pair spawning characterized by ventral mounting and multiple spawning over a several day period seen in walleye pollock and Atlantic gadid species.
The reproductive behavior of saffron cod ( Eleginus gracilis ) was examined in captivity. The captive saffron cod spawned demersal and slightly adhesive eggs, which dispersed and settled on the tank bottom. Ripe males and females did not display the ventral mounting behavior, which displayed in other gadid fishes during spawning. The aggressive behavior such as pushing, prodding and dorsal mounting did not observe between males during the breeding period. The female released all of her ripe eggs in a single spawning. Spawning involved one female and one or more males in bottom of the tank. Just after release of eggs by a female, one or a few males followed the female and spread sperm on the eggs using tail beats. The eggs slowly sank to the bottom.
The spawning behavior of saffron cod was similer to that of Pacific cod, but differed from the single-pair spawning characterized by ventral mounting and multiple spawning over a several day period seen in walleye pollock and Atlantic gadid species.
A－419 Shingo ITOH，Hiroyuki ISHIZAKI，Akio MASADATE，and Kanji NAKAJIMA
Migration of artificially produced Ishikari Bay herring juvenile from the Japan Sea to the Sea of Okhotsk in Hokkaido (Short Paper)
A－420 Hidetsugu YOSHIDA, Yoshiyuki TAKAYA, and Taihei MATSUDA
Migration and recapture rate of tagged barfin flounder Verasper moseri in Funka Bay, southwestern Hokkaido. (Short Paper)
A－420Yoshiyuki TAKAYA, Hidetsugu YOSHIDA and Taihei MATSUDA
Migration and size at release of tagged barfin flounder Verasper moseri in the coastal waters of Hidaka area, southwestern Hokkaido. (Short paper)
A－422 Keiichi NAGASE, Ryouji KUDO and Masaru TORISAWA
Components of hanasaki crab (Paralithodes brevipes) caught by pots with different mesh sizes（Short Paper)
A－423 Akira MIYAZONO and Hideki KISHIMURA
Multiple analysis of lipase activity in hepatopancreas of Japanese scallop Mizuhopecten yessoensis (Short Paper)
A－424 Akira MIYAZONO, Hiroya OKUMURA, Keiichi NAGAMA and Tsunemitsu SASAKI
Possibility of change in triglyceride concentrations affected by mariculture operation stress on juveniles of Japanese scallop Mizuhopecten yessoensis (Short Paper)