atsushi hagiwara | Nagasaki University (original) (raw)

Uploads

Papers by atsushi hagiwara

Fisheries Science, Oct 16, 2023

Nippon Suisan Gakkaishi, 2005

Nippon Suisan Gakkaishi, Nov 15, 2018

Aquaculture Science (Japan), Mar 20, 2008

Journal of Experimental Marine Biology and Ecology, Sep 1, 2019

Marine harpacticoid copepod Tigriopus japonicus is commonly distributed in the tide-pools and sho... more Marine harpacticoid copepod Tigriopus japonicus is commonly distributed in the tide-pools and shows benthic behavior. To determine its phototactic behavior, the movement pattern was investigated with different light wavelengths (white, peaks at 460 and 570nm; blue at 470 nm; green at 525 nm; and red at 660 nm) and intensities (0.5, 2.0, 3.5, 5.0, 15.0 W/m 2 ) related to developmental stages i.e., nauplius and adult. The eyespot of the two developmental groups efficiently absorbed the light wavelength from 400 to 550 nm, while the level of absorbance was different. For the horizontal phototactic behavior, nauplii showed negative phototaxis with the all tested light wavelengths and intensities ranging 0.5-5.0 W/m 2 , while they lost phototactic movement at 15 W/m 2 of all conducted light wavelengths except with the red light shown negative phototaxis. The adults showed negative phototaxis at 0.5 and 3.5 W/m 2 , while positive phototaxis at 2.0 W/m 2 regardless of light wavelengths. The vertical phototactic movement was only monitored with adults. At 2.0 and 3.0 W/m 2 , more than 40 % of adults showed planktonic behavior with the blue light. The results elucidate that T. japonicus has different patterns of phototaxis related to developmental stages which can be used to manipulate its distribution for dispersal.

Journal of Environmental Biology, Sep 30, 2020

Nippon Suisan Gakkaishi, 1992

Aquaculture Science, Dec 20, 2014

Aquaculture Science, Dec 20, 2013

Suisanzoshoku (Japan), Jun 20, 2010

Reviews in Fish Biology and Fisheries, Mar 4, 2023

A common goal among fisheries science professionals, stakeholders, and rights holders is to ensur... more A common goal among fisheries science professionals, stakeholders, and rights holders is to ensure the persistence and resilience of vibrant fish populations and sustainable, equitable fisheries in diverse aquatic ecosystems, from small headwater streams to offshore pelagic waters. Achieving this goal requires a complex intersection of science and management, and a recognition of the interconnections among people, place, and fish that govern these tightly coupled socioecological and sociotechnical systems. The World Fisheries Congress (WFC) convenes every four years and provides a unique global forum to debate and discuss threats, issues, and opportunities facing fish populations and

Aquaculture Science, Sep 20, 2005

The optimum rearing conditions of two species of amphidromous atyd shrimp Caridina typos and Cari... more The optimum rearing conditions of two species of amphidromous atyd shrimp Caridina typos and Caridina leucosticta collected from Koegawa River, Nagasaki, Japan, were examined

Aquaculture Science (Japan), Sep 20, 2007

Mitochondrial DNA Part B, Jul 3, 2019

Despite of the significance of three species of amphidromous atyd shrimp, Caridina typos, C. serr... more Despite of the significance of three species of amphidromous atyd shrimp, Caridina typos, C. serratirostris, and C. leucosticta in coastal ecosystem in southwest Japan, their morphological characteristics in early life history have not been clarified. It has been known that the distribution pattern of chromatophores differs in zoeal I and II stages of the above species. However, morphological features of later zoeal stages for species identification have not been unidentified. We compared the morphological features of the above species based on the larval specific under laboratory culture. Among the characters examined, only the shape of carapace is distinct and useful for species identification, and this can be used to identify larval insters after Zoea III. The zoeal instars were easily identified by the shape of pereopod, pleopod and tail. The larval developmental patterns of C. typos and C. serratirostris were almost the same. The number of zoeal instars and duration of C. leuco...

JOURNAL OF SUSTAINABILITY SCIENCE AND MANAGEMENT, 2021

Salinity is a known factor which shapes population dynamics and community structure through direc... more Salinity is a known factor which shapes population dynamics and community structure through direct and indirect effects towards aquatic ecosystems. The responses of Moina macrocopa (Cladocera) collected from Setiu Wetland lagoon (Terengganu) were evaluated through manipulative laboratory experiments to understand the ability of M. macrocopa to tolerate under high salinity stress. Specifically, the fatty acid composition, growth, survival and reproduction of this cladocerans species were examined. Sodium chloride (NaCl) were used in the treatments water with the concentration 0, 4, 6, 8, 12, and 15psu. Fatty acid levels were determined using Gas Chromatography and Mass Spectrophotometry (GC-MS). Results clearly indicate that normal conditions give the highest content of fatty acid, especially the polyunsaturated fatty acid content like EPA (eicosapentaenoic acid), ALA (alpha-linoleic acid), ARA (arachidonic acid) and DHA (docosahexaenoic acid). Furthermore, M. macrocopa survival also...