NIPPON SUISAN GAKKAISHI
Online ISSN : 1349-998X
Print ISSN : 0021-5392
ISSN-L : 0021-5392
Search
Advanced search
OR
Browse
Search
Volume 81, Issue 6
Displaying 1-28 of 28 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Foreword
Originals
  • Development of a system for counting populations and measuring the size of giant jellyfish using a towed upward-looking camera
    NAOTO HONDA
    2015 Volume 81 Issue 6 Pages 946-957
    Published: 2015
    Released on J-STAGE: December 03, 2015
    DOIhttps://doi.org/10.2331/suisan.81.946
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      A towed upward-looking underwater video camera system (TULCam) was developed for quantitative surveys to investigate the distribution of giant jellyfish. TULCam enables continuous, real-time observation of jellyfish with a video monitor on a boat connected through an optical fiber cable. Sea trials for observing giant jellyfish by TULCam were carried out in the Tsushima Strait in the Sea of Japan. The area density of Nemopilema nomurai, which were observed by TULCam towed at a speed of 7 knots at a depth of 20 m, was approximately 15 times that obtained by visual counting from on board. The depth and body size of the jellyfish were estimated on the basis of the towing speed and time taken for the jellyfish image to pass through the video monitor frame. The average bell size of jellyfish estimated by TULCam was almost the same as that of jellyfish caught by midwater trawl that was towed in the same area.
    View full abstract
    Download PDF (2564K)
  • Population structure of alfonsin Beryx splendens inferred from nucleotide sequences of the mitochondrial control region
    TAKASHI YANAGIMOTO, TAKESHI SAKAI, YOUSUKE OCHI, YOSHITOMI EBINA, TADA ...
    2015 Volume 81 Issue 6 Pages 958-963
    Published: 2015
    Released on J-STAGE: December 03, 2015
    DOIhttps://doi.org/10.2331/suisan.81.958
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      Alfonsin Beryx splendens is one of the most important commercial species for bottom fisheries in the world. For effective stock management, the genetic population structure was examined using nucleotide sequence variation of the mitochondrial control region. Samples were collected from four sites in the North Pacific Ocean, three sites in the South Indian Ocean, and one site in the North Atlantic Ocean. Significant differences among samples from the oceans were observed, but no clear genetic differences were observed among the sampling sites in each ocean. These results suggest that a single genetic stock is formed in each ocean.
    View full abstract
    Download PDF (745K)
  • Seasonal changes in the structure of a reed stand fish assemblage in Lake Kitaura, Ibaraki Prefecture, Japan
    SEIJI USUI, KOUKI KANOU, KAZUNORI ARAYAMA, MITSUHIKO SANO
    2015 Volume 81 Issue 6 Pages 964-972
    Published: 2015
    Released on J-STAGE: December 03, 2015
    DOIhttps://doi.org/10.2331/suisan.81.964
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      Seasonal patterns of fish assemblage structures in a reed stand area were examined in Lake Kitaura, central Japan, from April 2009 to March 2011. A total of 13,892 individuals (mainly larvae and juveniles) representing 9 families and 22 species were collected monthly by small seine net (mesh size 1 mm) throughout the study period. The numbers of fish species and individuals increased from spring to early summer in each year, with the highest species and individual numbers in June. The most abundant species were the gobiid Rhinogobius sp. (47.1% of the total number of individuals collected during the study period), the centrarchid Lepomis macrochirus macrochirus (19.8%), the gobiid Tridentiger brevispinis (12.5%), the salangid Salangichthys microdon (8.4%), the gobiid Gymnogobius urotaenia (3.6%), the cyprinid Pseudorasbora parva (2.9%), the osmerid Hypomesus nipponensis (2.0%) and the hemiramphid Hyporhamphus intermedius (1.4%). Based on the occurrence patterns and developmental stages of fishes sampled, it is suggested that the reed stand was used as a place of temporary growth and residence by a variety of fishes.
    View full abstract
    Download PDF (1509K)
  • Dietary value of microalga Rhodomonas sp. as a live food for sea cucumber Apostichopus japonicus larvae
    SATOSHI YAMAMOTO, MASANORI OKAUCHI, TAKAO YOSHIMATSU
    2015 Volume 81 Issue 6 Pages 973-978
    Published: 2015
    Released on J-STAGE: December 03, 2015
    DOIhttps://doi.org/10.2331/suisan.81.973
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      In order to examine the dietary value of a microalga Rhodomonas sp. as a live food for marine animals in aquaculture, small-scale rearing experiments of sea cucumber Apostichopus japonicus larvae were conducted in a laboratory. The survival rate of larvae fed Rhodomonas sp. was 89.3% on the 13th day of the experiments. Both the growth and metamorphosis to Doliolaria larval stage were more steady than those fed conventional live food. Proximate and fatty acid compositions of Rhodomonas sp. showed that it was rich in EPA, DHA and ARA, which are essential for the survival and healthy growth of marine animals. These factors might have positively affected the survival rate and growth rate of sea cucumber larvae fed Rhodomonas sp. According to the results obtained in the experiments, Rhodomonas sp. could be used as a novel live food for marine animals in aquaculture.
    View full abstract
    Download PDF (612K)
  • A study of the Coscinodiscus wailesii bloom of 2013 at Harima-Nada and Bisan-Strait, the Seto Inland Sea, Japan
    KUNINAO TADA, KENICHI OYAMA, KOICHI SHIRATSUCHI, TOSHIMITSU MASUI, TSU ...
    2015 Volume 81 Issue 6 Pages 979-986
    Published: 2015
    Released on J-STAGE: December 03, 2015
    DOIhttps://doi.org/10.2331/suisan.81.979
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      The cause of a significant Coscinodiscus wailesii bloom that occurred in October 2013 at the eastern part of the Seto Inland Sea was investigated. C. wailesii is a harmful species that causes serious damage to Nori (Pyropia) culture. This bloom had seldom been observed since 1990, which was thought to be the result of the gradual decrease in nutrient concentrations in this area after 1970 and in particular, a decrease in dissolved inorganic nitrogen concentration after 1990. However, a large C. wailesii bloom occurred in October 2013, just after vertical mixing of the water column. At that time, nutrient concentrations of bottom water suddenly decreased, but those of surface water did not increase. This was probably due to the consumption of nutrients by the C. wailesii bloom. In September 2013, one month prior to its bloom, both rainfall and solar irradiance were particularly high. Moreover, the euphotic zone depth was notably deeper. It was thought that the large C. wailesii bloom was due to the combination of sufficient nutrient supply, sufficient light irradiation and deeper euphotic zone in the vertical mixing period. Our results suggested that the recurrence of these factors could cause C. wailesii bloom to occur again even under a low nutrient situation.
    View full abstract
    Download PDF (1387K)
  • Effects of egg white on the thermal gel-forming ability of pink shrimp Pandalus eous meat
    KIGEN TAKAHASHI, MONE ITAKURA, HIROKAZU AMEMIYA, EMIKO OKAZAKI, HA THI ...
    2015 Volume 81 Issue 6 Pages 987-994
    Published: 2015
    Released on J-STAGE: December 03, 2015
    DOIhttps://doi.org/10.2331/suisan.81.987
    JOURNAL FREE ACCESS
    Show abstractHide abstract
      For effective utilization of irregular-sized and low-value pink shrimp Pandalus eous as a raw material of gel products, the thermal gel-forming ability of pink shrimp meat was improved by using egg white. The shrimp meat formed thermal gels in the presence of 5% egg white when heated at 50-90℃, whereas suwari gel was not obtained when heated at 30 or 40℃. SDS-PAGE patterns of the thermal gels showed that proteolysis such as myosin heavy chain degradation in the shrimp meat was well suppressed by the addition of egg white when heated at 60℃; however, egg white had weak inhibitory effects on the proteolysis at 40℃. These results indicated that the thermal gel-forming ability of pink shrimp meat was improved as a result of suppressing the proteolysis by the addition of egg white when heated at 50-90℃. Therefore, it was concluded that direct heating is suitable for producing thermal gel products from pink shrimp meat with egg white.
    View full abstract
    Download PDF (1206K)
Short Papers
Mini-Symposium
Examining the March 2014 judgement of International Court of Justice on “Whaling in the Antarctic”
I.
II.
Regional News
Highlights in Fisheries Science Research
Topics
Dynamic Women@Fisheries Science 33
Abstracts of Original Papers
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top