Seed production of bivalves utilizing endocrine control and production management of scallop aquaculture

Representative Organization: Tohoku University

2018/04/01 - 2019/03/31

Ogatsu bay, Onagawa bay, Others(laboratory)

Field survey, Mooring system(Observation buoy), Others(laboratory)

[Advanced seed production of bivalves based on application of endocrine control system] *Manipulation of sex and maturation by cerebral hormone: We planned to evaluate the effects of two types of gonadotropin releasing hormones (pyGnRH11AA-NH2 and pyGnRH12AA-OH), which likely regulate sex differentiation and maturation, on sex ratio and sexual maturation administrating pyGnRHs in vitro and in vivo to scallops. *Artificial spawning by cerebral hormone: The release from inhibitoty function of OMAF on serotonin-induced spawning is necessary to completely induce spawning by administration of serotonin. We planned to prepare specific antibody against recombinant full sequence OMAF protein in order to block OMAF function by absorption of endogenous OMAF with antibody and amplify serotonin function to induce spawning. *Control of settlement and metamorphosis of larvae of bivalves by the central nervous system: We focus on the development of monoamine and GnRH peptide neurons during embryonic and larval development of bivalves, oyster and manila clam, in relation to settlement and metamorphosis. We planned to quantitatively analyze monoamines and GnRH mRNA using HPLC-ECD and real time PCR, respectively to specify the neurons involving in settlement and metamorphosis. [Production management of scallop aquaculture] *Productivity of scallops and food availability in Ogatsu Bay: We planned to survey food availability from monthly line observation, number of facilities, annual production and productivity of scallops in Ogatsu Bay in order to understand environmental capacity in scallop farms and guarantee a sustainable production of scallops. *Evaluation of the environmental capacity in a scallop farm by satellite remote sensing: We planned to evaluate an availability of remote sensing data (MODIS) for estimation of chlorophyll a concentration in waters of Ogatsu Bay comparing with regular line observation and stationary measurement by observation buoy.

[Advanced seed production of bivalves based on application of endocrine control system] *Manipulation of sex and maturation by cerebral hormone: It is suggested that function of pyGnRH12AA-OH may accelerate the oogenesis and sex differentiation to female. *Artificial spawning by cerebral hormone: Pretreatment with 2 types of anti-OMAF antibody on four kinds of bivalve species (scallops, oysters, manila clams and Akazara-scallops) showed an increase of mobility and number of spawning of sperms using sperm motility analysis system. *Control of settlement and metamorphosis of larvae of bivalves by the central nervous system: Epinephrine, serotonin and GnRH mRNA expression were increased toward the settlement stage in both two species, suggesting possibility that these monoamines and GnRH peptide neurons in relation to settlement of larvae in general bivalve species. [production management of scallop aquaculture] *Productivity of scallops and food availability in Ogatsu Bay: Number of facility, annual production and productivity of scallops in Ogatsu Bay were down 8% (514), 45% (908 t) and 41% (11.0kg/rope) this year comparison with the previous year. It is thought that pronounced decrement of scallop productivity to originate from another factor different from environmental capacity. *Evaluation of the environmental capacity in a scallop farm by satellite remote sensing: It is shown that increment period in the amount of Chl.a estimated by MODIS data (MODIS Chl.a) entrain it in amount of in-situ Chl.a and an annual mean of amount of MODIS Chl.a was able to appreciate affective differences of amount of Chl.a in each bays.

FY2018 Seed production of bivalves utilizing endocrine control and production management of scallop aquaculture