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Yukio Agatsuma - One of the best experts on this subject based on the ideXlab platform.
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odor active compounds from the Gonads of mesocentrotus nudus sea urchins fed saccharina japonica kelp
PLOS ONE, 2020Co-Authors: Satomi Takagi, Eri Inomata, Yoichi Sato, Atsuko Kokubun, Yukio AgatsumaAbstract:Gonad size, color, texture and taste of Mesocentrotus nudus sea urchins collected from a barren can be improved by a short-term cage culture while being fed fresh Saccharina japonica kelp during May–July. We investigated the effect of S. japonica feeding during May–July on the improvement of gonad flavor in M. nudus collected from a barren. After feeding, we analyzed the odor-active volatile organic compounds (VOCs) from the Gonads using gas chromatography-mass spectrometry and GC-sniffing analyses and compared to those from the Gonads of wild sea urchins from an Eisenia kelp bed (fishing ground) and a barren. A total of 48 VOCs were detected from the Gonads of cultured and wild sea urchins. Of them, a larger number of odor-active compounds were detected in the Gonads of cultured sea urchins (25) than in those from the Eisenia bed (14) and the barren (6). Dimethyl sulfide from the Gonads of sea urchins from the barren was described as having a strong, putrid odor. Sea urchin-like aromas were attributed to 2-butanol, 2-ethylhexanol, benzaldehyde and ethylbenzene from the Gonads of cultured sea urchin and those of the Eisenia bed. Kelp feeding decreased the putrid odor from dimethyl sulfide, and enhanced pleasant, sweet aromas.
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Sporophyll of Undaria pinnatifida: a potential feed for the production of high-quality Gonads in the sea urchin Mesocentrotus nudus (A. Agassiz, 1864)
Journal of Applied Phycology, 2020Co-Authors: Satomi Takagi, Yuko Murata, Eri Inomata, Yukio AgatsumaAbstract:Previous study has shown that feeding fresh Saccharina japonica kelp at the late sporophyte stage to Mesocentrotus nudus from a barren can improve the gonad quality of the sea urchin. In particular, the basal frond portion of S . japonica , which accumulates amino acids during maturation, greatly enhances the sweet and umami taste of the Gonads. In the kelp Undaria pinnatifida , resources are accumulated in the blade for growth, then translocated to the sporophyll for maturation at the late sporophyte stage. In this study, we demonstrate the effects of feeding U . pinnatifida sporophyll to M . nudus from a barren from May to July on gonad quality (size, color ( L*a*b* ), and taste (free amino acids)) compared with the effects of feeding the U . pinnatifida midrib (negative control) and the basal frond portion of S . japonica (positive control). Feeding M . nudus the U. pinnatifida sporophyll, which has high protein, carbohydrate, and total and free alanine contents, improved M . nudus gonad size and color and increased alanine content and decreased arginine content in the gonad, similar to the results of feeding M . nudus the basal frond portion of S . japonica . The sporophyll increased free glutamic acid and decreased bitter-tasting amino acid contents in the Gonads of sea urchins, indicating that feeding of the sporophyll improved the gonad taste more than feeding of the basal frond portion of S . japonica . This study first indicated that the sporophyll of U . pinnatifida is a high potential feed to improve gonad taste of M . nudus . The appropriate feeding period in which gonad quality can be improved must be confirmed in order to shorten the duration of M . nudus culture.
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dietary effect of kelp saccharina japonica on gonad quantity and quality in sea urchins mesocentrotus nudus collected from a barren before the fishing season
Journal of Shellfish Research, 2018Co-Authors: Satomi Takagi, Yuko Murata, Eri Inomata, Hikaru Endo, Masakazu N Aoki, Yukio AgatsumaAbstract:The sea urchin Mesocentrotus nudus is commercially harvested between June and August in northeastern Japan. A previous study showed that feeding on Saccharina japonica between April and June resulted in gonad quantity and quality improvement in this species from a barren. No information is available on the optimal culture period for harvest before the fishing season. The purpose of this study was to determine whether gonad size and quality (color, texture, and taste) can be improved before the fishing season and to verify the possibility of an early harvest. The sea urchins M. nudus were collected from a barren and placed under two types of culture conditions: suspended cages in a bay and a laboratory circulation system. They were fed S. japonica between December and May or March. Gonad indices, hardness, and color [L*, a*, and b*, and ΔEab* (a unit of acceptable commercial color difference from a fishing ground for each treatment)], and free amino acid (FAA) contents of the urchin Gonads at the start of rearing experiments and at the end of cage (C) and laboratory feeding (LF) cultures were measured. These variables were also compared between LF and laboratory-starved urchins to confirm the dietary effect of this kelp. Gonad indices in treatments C and LF were significantly higher than those at the start of the experiment and those in laboratory starvation (P < 0.01), although there was no significant difference between C and LF. Gonads in treatment C were significantly softer than that at the start of the experiment (P < 0.0001). ΔEab* of Gonads in treatment C was the lowest, indicating that the gonad color was close to the preferred color. There was no significant difference in the total FAA content between C and LF treatments, whereas, of the umami FAA, glutamic acid content was significantly higher in Gonads from C than LF. Of the bittertasting FAA, tyrosine and valine contents were significantly higher in LF Gonads than in C Gonads. These results suggested that gonad size, hardness, and color of M. nudus were improved before the fishing season by initiating culture in December with S. japonica feeding.
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improvement of gonad quality of the sea urchin mesocentrotus nudus fed the kelp saccharina japonica during offshore cage culture
Aquaculture, 2017Co-Authors: Satomi Takagi, Yuko Murata, Eri Inomata, Hikaru Endo, Masakazu N Aoki, Yukio AgatsumaAbstract:Abstract In northern Japan, Saccharina kelps are natural diets for sea urchins and are known to enhance sea urchin gonad size. However, little is known about the effects of the kelp diet on gonad quality and consistency among individuals. In the present study, Mesocentrotus nudus adults collected from a barren were cultured in a suspended cage from late February to early June 2014 in Shizugawa Bay, Miyagi Prefecture. They were fed stipes of Undaria pinnatifida for 56 d followed by fresh Saccharina japonica kelp for 42 d. At the end of the culture period, gonad indices, gonad hardness, gonad color (L* (lightness), a* (redness), b* (yellowness)), free amino acid (FAA) contents in the Gonads, and sensory qualities of the cultured sea urchins (EC) were measured and compared to those of the natural population from the barren (EB) and those from the Eisenia bicycli s kelp bed (EK) in the bay. Gonad index and L* values of EC urchins were higher than those of urchins from the barren at the start of culture (SCB). Total color (L*, a*, b*) of the Gonads of EC and EK urchins were similar. Gonad hardness of EC and EK urchins was similar and lower than that of EB urchins, and the coefficients of variation of gonad index, color, and hardness were lower than those from the barren (SCB and EB). Sweet tasting alanine contents of the Gonads of EC urchins were markedly higher than those of the Gonads from the other urchin specimens. Bitter tasting FAA contents of the EC urchin Gonads were higher than those of EK and EB urchins, although arginine and lysine contents were lower than those of EB urchins. Sensory scores of overall taste of EC urchins were higher than those of EB urchins and similar to EK urchins, possibly due to the increased alanine content. These results suggest that gonad size, color, hardness, taste, and consistency among individuals of M. nudus collected from barrens can be improved to reach levels similar to those of urchins from the E. bicycli s kelp bed by cage culture with short-term feeding of Saccharina kelps. Changes in gonad qualities seemed to be mainly due to S. japonica as the food source because hard U. pinnatifida stipes were rarely eaten and had markedly low protein content. Extension of cage culture duration with S. japonica feeding from spring to summer would increase gonad size and further improve gonad quality.
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factors causing brown colored Gonads of the sea urchin strongylocentrotus nudus in northern honshu japan
Aquaculture, 2005Co-Authors: Yukio Agatsuma, Minoru Sato, Kazuya TaniguchiAbstract:In July 2001, to clarify the factors causing brown-colored Gonads in the sea urchin Strongylocentrotus nudus, we analyzed the body size, age, gonad size, and grade of gonad color of sea urchins in three Eisenia bicyclis beds and two crustose coralline beds in Miyagi Prefecture, Japan. Brown-colored Gonads were analyzed by HPLC and the potential causative pigments described. Gonad indices (gonad wet weight/body wet weight x 100) of S. nudus in Eisenia beds were significantly higher than those in crustose coralline habitats. In Eisenia beds, brown-colored Gonads were found in sea urchins with a test diameter >7 cm, which corresponded to age >7 years, and was associated with a decrease in gonad indices. Some urchins, however, had brown-colored Gonads despite their high gonad indices and young ages ( 7 years old and in those <7 years old with low gonad indices of <5%. These findings suggest that the brown colorization is correlated to aging and/or gonad size as determined by food availability. HPLC analysis of acetone extracts showed that two peaks at a retention time of around 16 min in brown Gonads were more intense than in bright yellow ones. The main causative pigment of brown colorization is likely to be contained in water- and fat-insoluble residues.
Satomi Takagi - One of the best experts on this subject based on the ideXlab platform.
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odor active compounds from the Gonads of mesocentrotus nudus sea urchins fed saccharina japonica kelp
PLOS ONE, 2020Co-Authors: Satomi Takagi, Eri Inomata, Yoichi Sato, Atsuko Kokubun, Yukio AgatsumaAbstract:Gonad size, color, texture and taste of Mesocentrotus nudus sea urchins collected from a barren can be improved by a short-term cage culture while being fed fresh Saccharina japonica kelp during May–July. We investigated the effect of S. japonica feeding during May–July on the improvement of gonad flavor in M. nudus collected from a barren. After feeding, we analyzed the odor-active volatile organic compounds (VOCs) from the Gonads using gas chromatography-mass spectrometry and GC-sniffing analyses and compared to those from the Gonads of wild sea urchins from an Eisenia kelp bed (fishing ground) and a barren. A total of 48 VOCs were detected from the Gonads of cultured and wild sea urchins. Of them, a larger number of odor-active compounds were detected in the Gonads of cultured sea urchins (25) than in those from the Eisenia bed (14) and the barren (6). Dimethyl sulfide from the Gonads of sea urchins from the barren was described as having a strong, putrid odor. Sea urchin-like aromas were attributed to 2-butanol, 2-ethylhexanol, benzaldehyde and ethylbenzene from the Gonads of cultured sea urchin and those of the Eisenia bed. Kelp feeding decreased the putrid odor from dimethyl sulfide, and enhanced pleasant, sweet aromas.
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Sporophyll of Undaria pinnatifida: a potential feed for the production of high-quality Gonads in the sea urchin Mesocentrotus nudus (A. Agassiz, 1864)
Journal of Applied Phycology, 2020Co-Authors: Satomi Takagi, Yuko Murata, Eri Inomata, Yukio AgatsumaAbstract:Previous study has shown that feeding fresh Saccharina japonica kelp at the late sporophyte stage to Mesocentrotus nudus from a barren can improve the gonad quality of the sea urchin. In particular, the basal frond portion of S . japonica , which accumulates amino acids during maturation, greatly enhances the sweet and umami taste of the Gonads. In the kelp Undaria pinnatifida , resources are accumulated in the blade for growth, then translocated to the sporophyll for maturation at the late sporophyte stage. In this study, we demonstrate the effects of feeding U . pinnatifida sporophyll to M . nudus from a barren from May to July on gonad quality (size, color ( L*a*b* ), and taste (free amino acids)) compared with the effects of feeding the U . pinnatifida midrib (negative control) and the basal frond portion of S . japonica (positive control). Feeding M . nudus the U. pinnatifida sporophyll, which has high protein, carbohydrate, and total and free alanine contents, improved M . nudus gonad size and color and increased alanine content and decreased arginine content in the gonad, similar to the results of feeding M . nudus the basal frond portion of S . japonica . The sporophyll increased free glutamic acid and decreased bitter-tasting amino acid contents in the Gonads of sea urchins, indicating that feeding of the sporophyll improved the gonad taste more than feeding of the basal frond portion of S . japonica . This study first indicated that the sporophyll of U . pinnatifida is a high potential feed to improve gonad taste of M . nudus . The appropriate feeding period in which gonad quality can be improved must be confirmed in order to shorten the duration of M . nudus culture.
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dietary effect of kelp saccharina japonica on gonad quantity and quality in sea urchins mesocentrotus nudus collected from a barren before the fishing season
Journal of Shellfish Research, 2018Co-Authors: Satomi Takagi, Yuko Murata, Eri Inomata, Hikaru Endo, Masakazu N Aoki, Yukio AgatsumaAbstract:The sea urchin Mesocentrotus nudus is commercially harvested between June and August in northeastern Japan. A previous study showed that feeding on Saccharina japonica between April and June resulted in gonad quantity and quality improvement in this species from a barren. No information is available on the optimal culture period for harvest before the fishing season. The purpose of this study was to determine whether gonad size and quality (color, texture, and taste) can be improved before the fishing season and to verify the possibility of an early harvest. The sea urchins M. nudus were collected from a barren and placed under two types of culture conditions: suspended cages in a bay and a laboratory circulation system. They were fed S. japonica between December and May or March. Gonad indices, hardness, and color [L*, a*, and b*, and ΔEab* (a unit of acceptable commercial color difference from a fishing ground for each treatment)], and free amino acid (FAA) contents of the urchin Gonads at the start of rearing experiments and at the end of cage (C) and laboratory feeding (LF) cultures were measured. These variables were also compared between LF and laboratory-starved urchins to confirm the dietary effect of this kelp. Gonad indices in treatments C and LF were significantly higher than those at the start of the experiment and those in laboratory starvation (P < 0.01), although there was no significant difference between C and LF. Gonads in treatment C were significantly softer than that at the start of the experiment (P < 0.0001). ΔEab* of Gonads in treatment C was the lowest, indicating that the gonad color was close to the preferred color. There was no significant difference in the total FAA content between C and LF treatments, whereas, of the umami FAA, glutamic acid content was significantly higher in Gonads from C than LF. Of the bittertasting FAA, tyrosine and valine contents were significantly higher in LF Gonads than in C Gonads. These results suggested that gonad size, hardness, and color of M. nudus were improved before the fishing season by initiating culture in December with S. japonica feeding.
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improvement of gonad quality of the sea urchin mesocentrotus nudus fed the kelp saccharina japonica during offshore cage culture
Aquaculture, 2017Co-Authors: Satomi Takagi, Yuko Murata, Eri Inomata, Hikaru Endo, Masakazu N Aoki, Yukio AgatsumaAbstract:Abstract In northern Japan, Saccharina kelps are natural diets for sea urchins and are known to enhance sea urchin gonad size. However, little is known about the effects of the kelp diet on gonad quality and consistency among individuals. In the present study, Mesocentrotus nudus adults collected from a barren were cultured in a suspended cage from late February to early June 2014 in Shizugawa Bay, Miyagi Prefecture. They were fed stipes of Undaria pinnatifida for 56 d followed by fresh Saccharina japonica kelp for 42 d. At the end of the culture period, gonad indices, gonad hardness, gonad color (L* (lightness), a* (redness), b* (yellowness)), free amino acid (FAA) contents in the Gonads, and sensory qualities of the cultured sea urchins (EC) were measured and compared to those of the natural population from the barren (EB) and those from the Eisenia bicycli s kelp bed (EK) in the bay. Gonad index and L* values of EC urchins were higher than those of urchins from the barren at the start of culture (SCB). Total color (L*, a*, b*) of the Gonads of EC and EK urchins were similar. Gonad hardness of EC and EK urchins was similar and lower than that of EB urchins, and the coefficients of variation of gonad index, color, and hardness were lower than those from the barren (SCB and EB). Sweet tasting alanine contents of the Gonads of EC urchins were markedly higher than those of the Gonads from the other urchin specimens. Bitter tasting FAA contents of the EC urchin Gonads were higher than those of EK and EB urchins, although arginine and lysine contents were lower than those of EB urchins. Sensory scores of overall taste of EC urchins were higher than those of EB urchins and similar to EK urchins, possibly due to the increased alanine content. These results suggest that gonad size, color, hardness, taste, and consistency among individuals of M. nudus collected from barrens can be improved to reach levels similar to those of urchins from the E. bicycli s kelp bed by cage culture with short-term feeding of Saccharina kelps. Changes in gonad qualities seemed to be mainly due to S. japonica as the food source because hard U. pinnatifida stipes were rarely eaten and had markedly low protein content. Extension of cage culture duration with S. japonica feeding from spring to summer would increase gonad size and further improve gonad quality.
Lanche Capel - One of the best experts on this subject based on the ideXlab platform.
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balancing the bipotential gonad between alternative organ fates a new perspective on an old problem
Developmental Dynamics, 2006Co-Authors: Yuna Kim, Lanche CapelAbstract:The embryonic Gonads give rise to one of two morphologically and functionally different organs, a testis or an ovary. Sex determination is the embryonic process that determines the developmental fate of the gonad. In mammals, sex determination is regulated by a DNA binding protein encoded on the Y chromosome, Sry, and it's downstream mediator, Sox9, which trigger testis determination in the bipotential gonad. However, evidence suggests that the extracellular signals. Fgf9 and Wnt4, are also required to establish divergent organogenesis of the gonad. In this review, we discuss how these extracellular signals interface with cell-autonomous factors to determine the fate of the mammalian gonad, and we derive a model that could provide a molecular explanation for testis determination in vertebrates where Sry is absent.
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divergent vascular mechanisms downstream of sry establish the arterial system in the xy gonad
Developmental Biology, 2002Co-Authors: Jennife Enna, Jeannie Karl, Lanche CapelAbstract:Although the primitive vasculature is identical in XX and XY genital ridges until 11.5 days postcoitum (dpc), by 12.5 dpc the XY gonad develops a distinct vasculature. This male-specific vasculature, which includes the development of a large coelomic vessel, develops coincident with expression of Sry and formation of testis cords. We show that similar levels of proliferation and vasculogenesis expand the primary vasculature in XX and XY Gonads. However, soon after Sry expression begins, the XY gonad recruits a large number of endothelial cells from the adjacent mesonephros, a mechanism totally absent in XX Gonads. These migrating cells do not contribute to venous or lymphatic development. Instead, these cells contribute to the arterial system, as indicated by expression of ephrinB2 and by elements of the Notch signaling pathway. This newly formed arterial system establishes a new pattern of blood flow in the XY gonad, which we speculate may have an important role in export of testosterone to masculinize the XY embryo.
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sry induces cell proliferation in the mouse gonad
Development, 2000Co-Authors: Jennife Schmahl, Eva M Eiche, Linda L Washbu, Lanche CapelAbstract:Sry is the only gene on the Y chromosome that is required for testis formation in mammals. One of the earliest morphological changes that occurs as a result of Sry expression is a size increase of the rudimentary XY gonad relative to the XX gonad. Using 5'-bromo-2'-deoxyuridine (BrdU) incorporation to label dividing cells, we found that the size increase corresponds with a dramatic increase in somatic cell proliferation in XY Gonads, which is not detected in XX Gonads. This male-specific proliferation was observed initially in the cells of the coelomic epithelium and occurred in two distinct stages. During the first stage, proliferation in the XY gonad was observed largely in SF1-positive cells and contributed to the Sertoli cell population. During the second stage, proliferation was observed in SF1-negative cells at and below the coelomic epithelium and did not give rise to Sertoli cells. Both stages of proliferation were dependent on Sry and independent of any other genetic differences between male and female Gonads, such as X chromosome dosage or other genes on the Y chromosome. The increase in cell proliferation began less than 24 hours after the onset of Sry expression, before the establishment of male-specific gene expression patterns, and before the appearance of any other known male-specific morphological changes in the XY gonad. Therefore, an increase in cell proliferation in the male coelomic epithelium is the earliest identified effect of Sry expression.
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mesonephric cell migration induces testis cord formation and sertoli cell differentiation in the mammalian gonad
Development, 1999Co-Authors: Christophe Tilma, Lanche CapelAbstract:In mammals a single gene on the Y chromosome, Sry, controls testis formation. One of the earliest effects of Sry expression is the induction of somatic cell migration from the mesonephros into the XY gonad. Here we show that mesonephric cells are required for cord formation and male-specific gene expression in XY Gonads in a stage-specific manner. Culturing XX Gonads with an XY gonad at their surface, as a ‘sandwich’, resulted in cell migration into the XX tissue. Analysis of sandwich Gonads revealed that in the presence of migrating cells, XX Gonads organized cord structures and acquired male-specific gene expression patterns. From these results, we conclude that mesonephric cell migration plays a critical role in the formation of testis cords and the differentiation of XY versus XX cell types.
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male specific cell migration into the developing gonad
Current Biology, 1997Co-Authors: Jane Martineau, Christophe Tilma, Katarina Nordqvis, Robi Lovellbadge, Lanche CapelAbstract:Abstract Background: The gene Sry acts as a developmental switch, initiating a pathway of gene activity that leads to the differentiation of testis rather than ovary from the indifferent gonad (genital ridge) in mammalian embryos. The early events following Sry expression include rapid changes in the topographical organization of cells in the XY gonad. To investigate the contribution of mesonephric cells to this process, Gonads from wild-type mice (CD1), and mesonephroi from a transgenic strain ubiquitously expressing β -galactosidase (ROSA26), were grafted together in vitro . After culture, organs were fixed and stained for β -galactosidase activity to identify cells contributed from the mesonephros to the male or female gonad. Results: Migration of mesonephric cells occurred into XY but not XX Gonads from 11.5–16.5 days post coitum (dpc). Somatic cells contributed from the mesonephros were distinguished by their histological location and by available cell-specific markers. Some of the migrating cells were endothelial; a second population occupied positions circumscribing areas of condensing Sertoli cells; and a third population lay in close apposition to endothelial cells. Conclusions: Migration from the mesonephros to the gonad is male specific at this stage of development and depends on an active signal that requires the presence of a Y chromosome in the gonad. The signals that trigger migration operate over considerable distances and behave as chemoattractants. We suggest that migration of cells into the bipotential gonad may have a critical role in initiating the divergence of development towards the testis pathway.
L Viglino - One of the best experts on this subject based on the ideXlab platform.
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delayed gametogenesis and progesterone levels in soft shell clams mya arenaria in relation to in situ contamination to organotins and heavy metals in the st lawrence river canada
Comparative Biochemistry and Physiology C-toxicology & Pharmacology, 2003Co-Authors: Ahmed Siah, Jocelyne Pellerin, Jean-claude Amiard, Emilien Pelletier, L ViglinoAbstract:There is a growing awareness that contaminants in the aquatic environment may alter steroid hormone levels and affect the reproductive success of the invertebrates. To verify if heavy metals and organotins affect sexual maturation in Mya arenaria, individuals were collected from July to November 1998, at different sites along the South coast of the St. Lawrence maritime estuary. Near the Rimouski harbour, clams showed high levels of tributyltin (TBT), DBT in the gonad, along with a lower gonado-somatic index {GSI=gonad wet weight (g)/body wet weight without shell (g)×100}, low progesterone levels and a delay in sexual maturation when compared to the reference site. Sites that had intermediate levels of contaminants exhibited intermediate responses of hormones and sexual maturation stages. It is therefore suggested that TBT, DBT are endocrine disruptors in clams. Further studies will however be necessary to investigate in more details how contaminants as TBT can affect the steroid hormones production in the Gonads of M. arenaria.
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sex alteration in soft shell clams mya arenaria in an intertidal zone of the saint lawrence river quebec canada
Comparative Biochemistry and Physiology C-toxicology & Pharmacology, 2003Co-Authors: F Gagne, Jocelyne Pellerin, Ch Blaise, Emilien Pelletier, M Douville, S Gauthierclerc, L ViglinoAbstract:Abstract The purpose of this study was to verify whether any changes in sex ratio might occur in soft-shell clams ( Mya arenaria ) located in an intertidal harbor zone located at the mouth of the Saguenay Fjord in the Saint Lawrence estuary (Baie Sainte-Catherine (BSC), Quebec, Canada) likely to be contaminated by organotin compounds. Bivalves were harvested at the BSC harbor site and from two reference sites. Condition index (weight to length ratio), gonado-somatic index, sex ratio, vitellin-like proteins, organotin concentrations in gonad tissue, maturation stages of the Gonads, the number of estradiol-17β binding sites and the capacity of female gonad extracts to produce estradiol-17β were determined in collected animals. Results showed that sex ratio in clams was significantly skewed toward males. Moreover, the condition and gonad-somatic indices, vitellin-like proteins in female Gonads and the capacity of female Gonads to produce estradiol-17β were significantly reduced at the harbor site with respect to the reference sites. Maturation status of male Gonads was clearly delayed at the harbor site. Additionally, gonad tissue contained tributyltin (TBT) at an average level of 109±18 ngSn/g dry wt. at the harbor site while organotins were not detected from the reference sites. Finally, female Gonads had a higher number of unoccupied estradiol binding sites at the harbor site indicating low levels of this steroid in this tissue. Overall, this paper is first to report that clams collected in the vicinity of a TBT contaminated harbor are subject to masculinizing effects which seems to be consistent with biological effects that organotins are known to exert toward some other marine invertebrates.
Eri Inomata - One of the best experts on this subject based on the ideXlab platform.
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odor active compounds from the Gonads of mesocentrotus nudus sea urchins fed saccharina japonica kelp
PLOS ONE, 2020Co-Authors: Satomi Takagi, Eri Inomata, Yoichi Sato, Atsuko Kokubun, Yukio AgatsumaAbstract:Gonad size, color, texture and taste of Mesocentrotus nudus sea urchins collected from a barren can be improved by a short-term cage culture while being fed fresh Saccharina japonica kelp during May–July. We investigated the effect of S. japonica feeding during May–July on the improvement of gonad flavor in M. nudus collected from a barren. After feeding, we analyzed the odor-active volatile organic compounds (VOCs) from the Gonads using gas chromatography-mass spectrometry and GC-sniffing analyses and compared to those from the Gonads of wild sea urchins from an Eisenia kelp bed (fishing ground) and a barren. A total of 48 VOCs were detected from the Gonads of cultured and wild sea urchins. Of them, a larger number of odor-active compounds were detected in the Gonads of cultured sea urchins (25) than in those from the Eisenia bed (14) and the barren (6). Dimethyl sulfide from the Gonads of sea urchins from the barren was described as having a strong, putrid odor. Sea urchin-like aromas were attributed to 2-butanol, 2-ethylhexanol, benzaldehyde and ethylbenzene from the Gonads of cultured sea urchin and those of the Eisenia bed. Kelp feeding decreased the putrid odor from dimethyl sulfide, and enhanced pleasant, sweet aromas.
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Sporophyll of Undaria pinnatifida: a potential feed for the production of high-quality Gonads in the sea urchin Mesocentrotus nudus (A. Agassiz, 1864)
Journal of Applied Phycology, 2020Co-Authors: Satomi Takagi, Yuko Murata, Eri Inomata, Yukio AgatsumaAbstract:Previous study has shown that feeding fresh Saccharina japonica kelp at the late sporophyte stage to Mesocentrotus nudus from a barren can improve the gonad quality of the sea urchin. In particular, the basal frond portion of S . japonica , which accumulates amino acids during maturation, greatly enhances the sweet and umami taste of the Gonads. In the kelp Undaria pinnatifida , resources are accumulated in the blade for growth, then translocated to the sporophyll for maturation at the late sporophyte stage. In this study, we demonstrate the effects of feeding U . pinnatifida sporophyll to M . nudus from a barren from May to July on gonad quality (size, color ( L*a*b* ), and taste (free amino acids)) compared with the effects of feeding the U . pinnatifida midrib (negative control) and the basal frond portion of S . japonica (positive control). Feeding M . nudus the U. pinnatifida sporophyll, which has high protein, carbohydrate, and total and free alanine contents, improved M . nudus gonad size and color and increased alanine content and decreased arginine content in the gonad, similar to the results of feeding M . nudus the basal frond portion of S . japonica . The sporophyll increased free glutamic acid and decreased bitter-tasting amino acid contents in the Gonads of sea urchins, indicating that feeding of the sporophyll improved the gonad taste more than feeding of the basal frond portion of S . japonica . This study first indicated that the sporophyll of U . pinnatifida is a high potential feed to improve gonad taste of M . nudus . The appropriate feeding period in which gonad quality can be improved must be confirmed in order to shorten the duration of M . nudus culture.
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dietary effect of kelp saccharina japonica on gonad quantity and quality in sea urchins mesocentrotus nudus collected from a barren before the fishing season
Journal of Shellfish Research, 2018Co-Authors: Satomi Takagi, Yuko Murata, Eri Inomata, Hikaru Endo, Masakazu N Aoki, Yukio AgatsumaAbstract:The sea urchin Mesocentrotus nudus is commercially harvested between June and August in northeastern Japan. A previous study showed that feeding on Saccharina japonica between April and June resulted in gonad quantity and quality improvement in this species from a barren. No information is available on the optimal culture period for harvest before the fishing season. The purpose of this study was to determine whether gonad size and quality (color, texture, and taste) can be improved before the fishing season and to verify the possibility of an early harvest. The sea urchins M. nudus were collected from a barren and placed under two types of culture conditions: suspended cages in a bay and a laboratory circulation system. They were fed S. japonica between December and May or March. Gonad indices, hardness, and color [L*, a*, and b*, and ΔEab* (a unit of acceptable commercial color difference from a fishing ground for each treatment)], and free amino acid (FAA) contents of the urchin Gonads at the start of rearing experiments and at the end of cage (C) and laboratory feeding (LF) cultures were measured. These variables were also compared between LF and laboratory-starved urchins to confirm the dietary effect of this kelp. Gonad indices in treatments C and LF were significantly higher than those at the start of the experiment and those in laboratory starvation (P < 0.01), although there was no significant difference between C and LF. Gonads in treatment C were significantly softer than that at the start of the experiment (P < 0.0001). ΔEab* of Gonads in treatment C was the lowest, indicating that the gonad color was close to the preferred color. There was no significant difference in the total FAA content between C and LF treatments, whereas, of the umami FAA, glutamic acid content was significantly higher in Gonads from C than LF. Of the bittertasting FAA, tyrosine and valine contents were significantly higher in LF Gonads than in C Gonads. These results suggested that gonad size, hardness, and color of M. nudus were improved before the fishing season by initiating culture in December with S. japonica feeding.
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improvement of gonad quality of the sea urchin mesocentrotus nudus fed the kelp saccharina japonica during offshore cage culture
Aquaculture, 2017Co-Authors: Satomi Takagi, Yuko Murata, Eri Inomata, Hikaru Endo, Masakazu N Aoki, Yukio AgatsumaAbstract:Abstract In northern Japan, Saccharina kelps are natural diets for sea urchins and are known to enhance sea urchin gonad size. However, little is known about the effects of the kelp diet on gonad quality and consistency among individuals. In the present study, Mesocentrotus nudus adults collected from a barren were cultured in a suspended cage from late February to early June 2014 in Shizugawa Bay, Miyagi Prefecture. They were fed stipes of Undaria pinnatifida for 56 d followed by fresh Saccharina japonica kelp for 42 d. At the end of the culture period, gonad indices, gonad hardness, gonad color (L* (lightness), a* (redness), b* (yellowness)), free amino acid (FAA) contents in the Gonads, and sensory qualities of the cultured sea urchins (EC) were measured and compared to those of the natural population from the barren (EB) and those from the Eisenia bicycli s kelp bed (EK) in the bay. Gonad index and L* values of EC urchins were higher than those of urchins from the barren at the start of culture (SCB). Total color (L*, a*, b*) of the Gonads of EC and EK urchins were similar. Gonad hardness of EC and EK urchins was similar and lower than that of EB urchins, and the coefficients of variation of gonad index, color, and hardness were lower than those from the barren (SCB and EB). Sweet tasting alanine contents of the Gonads of EC urchins were markedly higher than those of the Gonads from the other urchin specimens. Bitter tasting FAA contents of the EC urchin Gonads were higher than those of EK and EB urchins, although arginine and lysine contents were lower than those of EB urchins. Sensory scores of overall taste of EC urchins were higher than those of EB urchins and similar to EK urchins, possibly due to the increased alanine content. These results suggest that gonad size, color, hardness, taste, and consistency among individuals of M. nudus collected from barrens can be improved to reach levels similar to those of urchins from the E. bicycli s kelp bed by cage culture with short-term feeding of Saccharina kelps. Changes in gonad qualities seemed to be mainly due to S. japonica as the food source because hard U. pinnatifida stipes were rarely eaten and had markedly low protein content. Extension of cage culture duration with S. japonica feeding from spring to summer would increase gonad size and further improve gonad quality.