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Sten I. Siikavuopio - One of the best experts on this subject based on the ideXlab platform.
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the effects of tank system water velocity and water movement on survival somatic and gonad growth of juvenile and adult green sea urchin Strongylocentrotus Droebachiensis
Aquaculture Research, 2015Co-Authors: Philip James, Sten I. SiikavuopioAbstract:AbstractThe effects of water velocity and tipping frequency(water movement) on survival, somatic and gonadgrowth of juvenile and adult green sea urchin,Strongylocentrotus Droebachiensis were investigated.Juvenile and adult urchins were held in ‘laminar’or ‘tipper’ tanks. Both were supplied with threeinlet water flows (1.5, 3.0 and 7.5 L min 1 )which converted to water velocities of 0.28, 0.57and 1.43 cm s 1 in the ‘laminar’ tanks and tip-ping frequencies of 30, 10 and 5 s in the ‘tipper’tanks. Juvenile sea urchins had significantly lowermortality and greater somatic growth when heldin ‘laminar’ flow tanks compared with ‘tipper’tanks. The varying water velocities tested in the‘laminar’ flow treatment had no effect on thegrowth of juvenile sea urchins. The juvenile seaurchins in the ‘tipping’ treatment held at high tip-ping frequency had significantly slower growththan those in the medium and low tippingfrequency treatments. There were no differences inmortality or gonad growth in the adult seaurchins regardless of treatment. The ‘laminar’ flowtanks retained significantly more organic materialcompared with the ‘tipper’ tanks. The authors dis-cuss the effects of water velocity and tipping fre-quencies in system design for aquaculture of seaurchins.Keywords: Strongylocentrotus Droebachiensis,‘laminar’ and ‘tipper’ systems, water velocity, tip-ping frequency, somatic and gonad growthIntroductionThe aquaculture of sea urchins can be dividedinto two forms. The first is gonad enhancement ofwild-caught adults fed prepared diets in captivityfor a short period of time (Lawrence, Olave,Otaiza, Lawrence & Bustos 1997; Kelly, Brodie M Siikavuopio, Christiansen & Dale2006; James 2007). The second is closed cycleculture which involves spawning of adult broodstock then rearing larvae and juveniles through tomarket size (Grosjean, Spirlet, Gosselin, Va€italin-gon & Jangoux 1998; Lawrence 2007; Siikavuo-pio & James 2011). Both forms require suitableholding systems (Lesser & Walker 1998) and yetthere is a paucity of research regarding systemdesigns and the key factors that should be consid-ered in such systems, particularly for growingjuvenile urchins (Pearce, Williams, Yuan, Castell& Robinson 2005; Daggett, Pearce & Robinson2006; James 2007).The few studies that have investigated sea urchinholding systems have found little differences ingonad characteristics between holding types, butsignificant differences in tank cleaning times andurchin survival (Motnikar, Marson & Tetreault1998; Daggett et al. 2006). Daggett, et al. (2006)suggested that ‘the actual movement of water ortank volume replacement time was the most impor-tant factor in urchin mortality’ in their study. Theanatomy of sea urchins makes them particularlysusceptible to the effects of water movement due tothe rudimentary nature of their circulatory and
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effects of size and temperature on growth and feed conversion of juvenile green sea urchin Strongylocentrotus Droebachiensis
Aquaculture, 2012Co-Authors: Sten I. Siikavuopio, Philip James, Bjornsteinar Saether, Hege Lysne, Tor Andreas Samuelsen, Atle MortensenAbstract:Abstract Juvenile green sea urchins, Strongylocentrotus Droebachiensis ranging in size from 0.1 to 30 g were held in individual compartments at four constant temperatures (6, 10, 12 and 14 °C) ( n = 54 per temperature treatment) for a period of 100 days. Growth, survival, feed intake and feed conversion ratio (FCR) of the urchins were monitored during this period. There was no mortality throughout the experimental period. The growth of the urchins was significantly affected by seawater temperature with the group held at 6 °C having a significantly lower specific growth rate (SGR) (% body growth per day) than the urchins held in any other temperature treatment. There were no significant differences in specific growth rate (SGR) between the urchins held in the other three temperature groups (10, 12 and 14 °C). Feed conversion ratio (FCR) (grams of feed used to increase the body wet weight by one gram) was also significantly affected by temperature with urchins held at 10 °C having significantly lower FCR values (2.2 ± 0.7) than those held in the 6 °C temperature group (3.39 ± 1.6). These in turn were significantly lower than those in the 12 °C temperature groups (7.02 ± 1.5) and these were significantly lower than those in the 14 °C temperature group (8.8 ± 2.2). Within the temperature groups, FCR was size dependent and decreased with increasing urchin size. In conclusion, the present study shows that a rearing temperature of 10 °C appears to be optimal for juvenile green sea urchins in the size range of 0.1 to 30 g when both feed conversion and growth rate are taken into account.
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long term effects of stocking density on somatic growth gonad index and survival of the juvenile sea urchin Strongylocentrotus Droebachiensis
Aquaculture International, 2011Co-Authors: Sten I. Siikavuopio, Philip JamesAbstract:Juvenile Strongylocentrotus Droebachiensis (average wet weight = 4.0 g) were held at three initial stocking densities (15, 30 and 60 animals per tray, which equates to 0.25, 0.5 and 1 kg sea urchins/m2 surface area, respectively) under constant light and temperature conditions (LD 24:0 and 8.8°C) for 380 days. The somatic growth and survival of the urchins were monitored during this period, and the gonad index (GI) was measured at the conclusion of the experiment. The sea urchins in the two lowest stocking density groups had 100% survival after 380 days in contrast to the highest stocking density group, which only had 67% survival at the conclusion of the experiment. Somatic growth was significantly higher in the lowest density group than in the medium density group, and this in turn was significantly higher than in the high-density group. The injury occurrence was highest in the high-density group (20%), lower in the medium group (7%), and there were no injuries observed (0%) in the low density groups. There were no significant differences in GI between the groups at the end of the experiment. In conclusion, the present study showed that stocking density has significant effects on somatic growth and survival of juvenile green sea urchin, S. Droebachiensis and should be taken into consideration when designing sea urchin holding systems.
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Effects of body weight and temperature on feed intake, gonad growth and oxygen consumption in green sea urchin, Strongylocentrotus Droebachiensis
Aquaculture, 2008Co-Authors: Sten I. Siikavuopio, Atle Mortensen, Jørgen S. ChristiansenAbstract:Abstract The current study describes the metabolic performance of adult green sea urchin Strongylocentrotus Droebachiensis in terms of oxygen consumption, feed intake and gonad growth in relation to body weight and temperature. The experiments were conducted at six constant temperatures (4, 6, 8, 10, 12 and 14 °C), and with three body size groups, i.e. small (S, 40 g), medium (M, 65 g), and large (L, 100 g). Results show that 10–12 °C is the optimum temperature for gonad growth for 40–100-g green sea urchin during summer/autumn, and that there is an inverse relationship between optimum temperature and size. Contrary to gonad growth, both feed intake and oxygen consumption continued to increase throughout the entire temperature range (4–14 °C). The Q10 values for oxygen consumption of fed animals were in the normal range (1.72–3.01), while the corresponding values for starved animals were low (1.17–1.36), indicating negligible effects of temperature on aerobic metabolism during starvation. The energetic analyses indicate a poorly developed regulation of energy intake in relation to energy expenditure. The oxygen consumption data from this study can, together with a still missing description of the relationship between oxygen saturation and somatic and gonad growth, be used to evaluate the water requirement of green sea urchin in aquaculture.
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seasonal variation in feed intake under constant temperature and natural photoperiod in the green sea urchin Strongylocentrotus Droebachiensis
Aquaculture, 2007Co-Authors: Sten I. Siikavuopio, Jørgen S. Christiansen, Bjornsteinar Saether, Trine DaleAbstract:Abstract Feed intake, body growth, and gonad growth of adult green sea urchin Strongylocentrotus Droebachiensis were investigated at a constant temperature (10 °C) and a simulated natural photoperiod (70 °N) for 848 days. Three size groups of sea urchins with an initial test diameter of 30–40 mm (small, S, N = 32), 40–50 mm (medium, M, N = 36), and 50–60 mm (large, L, N = 32) were cultured individually and fed a formulated moist feed in excess. During the first period of the trial, the test diameter (days 0–560), the feed conversion ratio (days 0–560), and the gonad index (GI, days 0 and 560) were recorded. The feed intake (FI) was registered during the entire period (848 days) and varied strongly with season for all size groups. Hence, the FI was significantly higher in summer (0.5–0.6 g per animal per day) than in winter (0.2–0.3 g per animal per day). The test diameter, on the other hand, increased in a linear manner with no apparent seasonality. The S group displayed the fastest increase in test diameter and the highest ingestion rare followed by size groups M and L. By day 560, the GI had reached 33–35% irrespective of size group, which is the highest GI-value reported for this species. Overall, our findings demonstrate that the feed intake of the adult green sea urchins is strongly linked to season at a constant temperature, and that the seasonality in feed intake is maintained for years in captivity.
Robert Eric Scheibling - One of the best experts on this subject based on the ideXlab platform.
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chapter 26 Strongylocentrotus Droebachiensis
Developments in Aquaculture and Fisheries Science, 2013Co-Authors: Robert Eric Scheibling, Bruce G. HatcherAbstract:Strongylocentrotus Droebachiensis, the green sea urchin, has a broad Arctic-boreal distribution and is commonly associated with laminarian kelp. As an omnivorous grazer, its feeding capabilities and preferences have profound effects on the structure and dynamics of benthic communities. It exhibits an annual reproductive cycle and has planktrophic larval development. Growth and reproductive rates are largely dependent on the quantity and quality of available food. Larval behavior can influence patterns of dispersal in the plankton and settlement on the seabed, but the importance of predation or other agents of mortality at early life history stages is poorly understood. Fish and decapod crustaceans are major predators of larger juveniles and adults and may play an important role in population regulation. Strongylocentrotus Droebachiensis is susceptible to acute and chronic infections by microbial pathogens and parasitic nematodes. In the northwest Atlantic, mass mortality during outbreaks of an amoebic disease can have profound impacts on sea urchin populations and ecosystem state. Green sea urchins have been extensively fished or cultured for roe since the late 1980s. Aquaculture research is contributing new knowledge of the nutritional and reproductive physiology of the species.
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Fatty acid profiles in the gonads of the sea urchin Strongylocentrotus Droebachiensis on natural algal diets
Marine Ecology Progress Series, 2008Co-Authors: Jennifer R. Kelly, Robert Eric Scheibling, Sara J. Iverson, Patrick GagnonAbstract:We examined fatty acid (FA) compositions of gonads of the green sea urchin Strongylocentrotus Droebachiensis collected from a grazing aggregation (front) at the edge of a kelp bed and from barrens dominated by coralline algae, and those of urchins fed single algal diets in the laboratory. We compared these gonad FAs with those of the algal diets, which represented known urchin food sources in rocky subtidal habitats. Gonads of urchins collected from both wild habitats, and of urchins fed kelp Saccharina longicruris in the laboratory, contained more lipid than did urchins fed single diets of barrens macroalgae (Agarum clathratum, coralline red algae or Desmarestia viridis). Substantial biosynthesis of non-methylene interrupted dienes and other FAs by urchins markedly affected their overall FA signatures. Although the FA compositions of gonads of laboratory-fed urchins did not clearly correspond with those of their diets, 3 clusters of urchins were distinguished in multivariate space using multidimensional scaling (MDS): (1) urchins fed single diets of barrens macroalgae in the laboratory; (2) urchins fed S. longicruris in the laboratory or collected from the grazing front; and (3) urchins from the barrens. Characteristics of FA signatures found in urchins from the barrens suggested the occurrence of benthic diatoms in their diet. Our results indicate that, while the FA signatures of urchin gonads are affected by diet and can be used to differentiate feeding groups of urchins in the laboratory and field, significant de novo biosynthesis and/or modification of FAs precludes correspondence of urchin FAs to those of their algal diets.
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settlement behaviour and early post settlement predation of the sea urchin Strongylocentrotus Droebachiensis
Journal of Experimental Marine Biology and Ecology, 2008Co-Authors: Robert Eric Scheibling, Mark C RobinsonAbstract:Abstract We examined behaviour of competent larvae of the green sea urchin Strongylocentrotus Droebachiensis provided with pebbles encrusted with coralline red algae, a strong settlement inducer, in laboratory experiments. Larvae settled at greater frequencies on upward-facing coralline surfaces and in small gaps between coralline and glass surfaces than expected by a random distribution of settlement. These patterns may be explained by encounter rate with inductive cues. There was no change in settler distributions within ~ 1 week of settlement, indicating no net movement between adjacent microhabitats. In flow, live and recently killed larvae settled or were passively entrapped at greater frequencies on high- than low-rugosity coralline crusts. Recent settlers (0.5-1 mm test diameter) were consumed by small decapod crustaceans and bulldozed by periwinkles. Juveniles became less vulnerable to predation by hermit crabs with increasing size, and reached a growth refuge at ~ 10 mm test diameter. Our laboratory findings suggest that the cryptic distribution of recent settlers is probably not due to microhabitat selection by settling larvae or early post-settlement migration, at least not in response to physical cues such as light or surface texture. Differential rates predation of young juveniles between exposed and cryptic habitats cannot be ruled out as an important determinant of this pattern.
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invertebrate fauna associated with kelp enhances reproductive output of the green sea urchin Strongylocentrotus Droebachiensis
Journal of Experimental Marine Biology and Ecology, 2007Co-Authors: Danielle M Knip, Robert Eric ScheiblingAbstract:Abstract Kelp beds are species rich communities providing food and shelter for a wide range of invertebrate and fish species. As the dominant subtidal grazer in the northwest Atlantic, the green sea urchin Strongylocentrotus Droebachiensis can severely limit the distribution and abundance of kelps and influence the structure of the rocky subtidal community. Urchins form large mobile feeding aggregations (termed fronts) along the margins of kelp beds that destructively graze kelps and, incidentally, the associated invertebrate fauna. Urchins along the leading edge of fronts climb upon and consume kelp fronds and trailing urchins graze the remaining stipes and holdfasts. The fronds are often encrusted with an epiphytic bryozoan Membranipora membranacea , while the holdfasts harbour many sessile and cryptic invertebrates, such as mussels and brittle stars. The effects on urchin growth (as test diameter and body weight) and reproduction (as gonad index) of feeding on kelp fronds or holdfasts, both with or without the natural associated fauna, were examined in a 95-day experiment in the laboratory. Female urchins had a greater gonad index than males in all diet treatments at the end of the experiment. Females fed holdfasts with associated fauna had a greater gonad index that those fed cleaned holdfasts, but there was no difference between these treatments for males. For urchins fed fronds, there was no significant difference in gonad index of either sex between treatments with and without M. membranacea , although urchins fed at a lower rate on bryozoan-encrusted fronds. Test diameter increased by 1–7 mm (based on tank means) during the experiment, but there was no effect of diet or sex on growth rate. The finding that a diet of kelp with naturally associated fauna can significantly enhance gonad production in S. Droebachiensis has important implications for the development of optimal aquaculture and harvesting practices.
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effect of dietary history and algal traits on feeding rate and food preference in the green sea urchin Strongylocentrotus Droebachiensis
Journal of Experimental Marine Biology and Ecology, 2007Co-Authors: Devin A Lyons, Robert Eric ScheiblingAbstract:Abstract Feeding behaviour is influenced by a variety of factors, including nutritional requirements, the quality of available foods, and environmental conditions. We examined the effect of two factors, food morphology and dietary history, on the feeding rate and preference of the sea urchin Strongylocentrotus Droebachiensis. Standardizing food shape and structure did not alter urchins' expected preference for the native kelp Laminaria longicruris over the invasive alga Codium fragile ssp. tomentosoides. However, when foods containing L. longicuris were shaped to mimic the algae, the C. fragile mimic was consumed more rapidly than the kelp mimic. Dietary history had no effect on single diet feeding rate. Urchins feeding on C. fragile consistently consumed twice as much (by mass) as those fed kelp, regardless of their previous diet. Despite higher feeding rates on C. fragile, urchins feeding on this alga were unable to compensate for its low energetic content and ingested less energy. Dietary history had a short-term effect on food preference, with urchins tending to prefer less familiar foods. Our findings suggest that urchins feed on C. fragile at a high rate, due to ease of handling and/or compensatory feeding, and that they do not a have strict preference hierarchy. Rather, food choice appears to reflect active maintenance of a mixed diet.
Atle Mortensen - One of the best experts on this subject based on the ideXlab platform.
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effects of size and temperature on growth and feed conversion of juvenile green sea urchin Strongylocentrotus Droebachiensis
Aquaculture, 2012Co-Authors: Sten I. Siikavuopio, Philip James, Bjornsteinar Saether, Hege Lysne, Tor Andreas Samuelsen, Atle MortensenAbstract:Abstract Juvenile green sea urchins, Strongylocentrotus Droebachiensis ranging in size from 0.1 to 30 g were held in individual compartments at four constant temperatures (6, 10, 12 and 14 °C) ( n = 54 per temperature treatment) for a period of 100 days. Growth, survival, feed intake and feed conversion ratio (FCR) of the urchins were monitored during this period. There was no mortality throughout the experimental period. The growth of the urchins was significantly affected by seawater temperature with the group held at 6 °C having a significantly lower specific growth rate (SGR) (% body growth per day) than the urchins held in any other temperature treatment. There were no significant differences in specific growth rate (SGR) between the urchins held in the other three temperature groups (10, 12 and 14 °C). Feed conversion ratio (FCR) (grams of feed used to increase the body wet weight by one gram) was also significantly affected by temperature with urchins held at 10 °C having significantly lower FCR values (2.2 ± 0.7) than those held in the 6 °C temperature group (3.39 ± 1.6). These in turn were significantly lower than those in the 12 °C temperature groups (7.02 ± 1.5) and these were significantly lower than those in the 14 °C temperature group (8.8 ± 2.2). Within the temperature groups, FCR was size dependent and decreased with increasing urchin size. In conclusion, the present study shows that a rearing temperature of 10 °C appears to be optimal for juvenile green sea urchins in the size range of 0.1 to 30 g when both feed conversion and growth rate are taken into account.
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Effects of body weight and temperature on feed intake, gonad growth and oxygen consumption in green sea urchin, Strongylocentrotus Droebachiensis
Aquaculture, 2008Co-Authors: Sten I. Siikavuopio, Atle Mortensen, Jørgen S. ChristiansenAbstract:Abstract The current study describes the metabolic performance of adult green sea urchin Strongylocentrotus Droebachiensis in terms of oxygen consumption, feed intake and gonad growth in relation to body weight and temperature. The experiments were conducted at six constant temperatures (4, 6, 8, 10, 12 and 14 °C), and with three body size groups, i.e. small (S, 40 g), medium (M, 65 g), and large (L, 100 g). Results show that 10–12 °C is the optimum temperature for gonad growth for 40–100-g green sea urchin during summer/autumn, and that there is an inverse relationship between optimum temperature and size. Contrary to gonad growth, both feed intake and oxygen consumption continued to increase throughout the entire temperature range (4–14 °C). The Q10 values for oxygen consumption of fed animals were in the normal range (1.72–3.01), while the corresponding values for starved animals were low (1.17–1.36), indicating negligible effects of temperature on aerobic metabolism during starvation. The energetic analyses indicate a poorly developed regulation of energy intake in relation to energy expenditure. The oxygen consumption data from this study can, together with a still missing description of the relationship between oxygen saturation and somatic and gonad growth, be used to evaluate the water requirement of green sea urchin in aquaculture.
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Effects of carbon dioxide exposure on feed intake and gonad growth in green sea urchin, Strongylocentrotus Droebachiensis
Aquaculture, 2007Co-Authors: Sten I. Siikavuopio, Trine Dale, Atle Mortensen, Atle FossAbstract:Abstract The effects of carbon dioxide (CO 2(aq) ) on gonad growth and feed intake in green sea urchin, Strongylocentrotus Droebachiensis , were examined. Adult sea urchins with a mean (S.D.) live weight of 50.0 (11.2) g were exposed to two levels of carbon dioxide (CO 2(aq) ), (1.1 (control) and 18.1 mg l − 1 ), for 56 days at 6.0 °C and 33‰. Gonad growth was significantly reduced in the high CO 2 concentration group compared to the control group. In the high carbon dioxide treatment, gonad growth was 67% less than the control treatment. Weekly feed intake and total feed consumption were significantly reduced in the high concentration group. The reduction in gonad growth was attributed to a decrease in feed intake and impaired feed conversion efficiency. The present study demonstrates that adult green sea urchins show low tolerance to increased carbon dioxide levels, and are unable to maintain high gonad growth facing such conditions.
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Effects of hypoxia on feed intake and gonad growth in the green sea urchin, Strongylocentrotus Droebachiensis
Aquaculture, 2007Co-Authors: Sten I. Siikavuopio, Trine Dale, Atle Mortensen, Atle FossAbstract:Abstract The effects of oxygen content on gonad growth and feed intake in “green sea urchin”, Strongylocentrotus Droebachiensis, were examined. Adult sea urchins with a mean (S.D.) live weight of 51.0 (12.2) g were reared at oxygen levels of 4.0, 6.0 (hypoxia) and 9.5 mg l− 1 (normoxia), for 54 days at 8.0 °C and 33‰. Gonad growth and total food consumption were significantly higher in the control group (normoxia) compared with the hypoxic groups at the end of the experiment. Weekly feed intake and total feed consumption were significantly reduced in the two hypoxic groups. The reduction in gonad growth was attributed to a decrease in feed intake and impaired food conversion efficiency. Overall, our findings suggest that adult green sea urchins show low tolerance to hypoxia, and are unable to maintain high gonad growth facing such conditions.
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the effects of stocking density on gonad growth survival and feed intake of adult green sea urchin Strongylocentrotus Droebachiensis
Aquaculture, 2007Co-Authors: Sten I. Siikavuopio, Trine Dale, Atle MortensenAbstract:Abstract In this study the effects of different stocking densities on survival, gonad growth and feed intake in adult green sea urchin ( Strongylocentrotus Droebachiensis ) were examined. Two size groups of sea urchins with respective initial mean weight of 45 g (S) and 70 g (L) were used. The experiments were carried out in 755 l plastic tanks divided into chambers by vertical fibreglass lamellae. In the two experiments stocking densities of 6, 12, 14 and 16 kg m − 2 (Exp I) and 3, 6 and 8 kg m − 2 (Exp II) were used. Sea urchins reared individually in compartmentalised raceways were used as controls in both experiments. All groups were fed a formulated moist feed ad libitum for 60 days at 8 °C (± 0.5). Mortality was observed in all groups, except for the control group and the lowest density group of large sea urchins (3 kg m − 2 , L). Both mortality and occurrence of injuries increased significantly with increasing stocking density in both experiments and for both size groups. In the highest density groups mortality was 60% (L) and 80% (S). There was a significant increase in gonad index during the experimental period in both experiments. Increased stocking density had a significantly negative effect on gonad growth in both size groups while feed intake was unaffected. The results show that adult S. Droebachiensis can maintain high survival rate and high gonad growth at stocking densities up 6 kg m − 2 in holding facilities of the design used in the present study.
Trine Dale - One of the best experts on this subject based on the ideXlab platform.
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seasonal variation in feed intake under constant temperature and natural photoperiod in the green sea urchin Strongylocentrotus Droebachiensis
Aquaculture, 2007Co-Authors: Sten I. Siikavuopio, Jørgen S. Christiansen, Bjornsteinar Saether, Trine DaleAbstract:Abstract Feed intake, body growth, and gonad growth of adult green sea urchin Strongylocentrotus Droebachiensis were investigated at a constant temperature (10 °C) and a simulated natural photoperiod (70 °N) for 848 days. Three size groups of sea urchins with an initial test diameter of 30–40 mm (small, S, N = 32), 40–50 mm (medium, M, N = 36), and 50–60 mm (large, L, N = 32) were cultured individually and fed a formulated moist feed in excess. During the first period of the trial, the test diameter (days 0–560), the feed conversion ratio (days 0–560), and the gonad index (GI, days 0 and 560) were recorded. The feed intake (FI) was registered during the entire period (848 days) and varied strongly with season for all size groups. Hence, the FI was significantly higher in summer (0.5–0.6 g per animal per day) than in winter (0.2–0.3 g per animal per day). The test diameter, on the other hand, increased in a linear manner with no apparent seasonality. The S group displayed the fastest increase in test diameter and the highest ingestion rare followed by size groups M and L. By day 560, the GI had reached 33–35% irrespective of size group, which is the highest GI-value reported for this species. Overall, our findings demonstrate that the feed intake of the adult green sea urchins is strongly linked to season at a constant temperature, and that the seasonality in feed intake is maintained for years in captivity.
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sensory quality of gonads from the green sea urchin Strongylocentrotus Droebachiensis fed different diets
Journal of Shellfish Research, 2007Co-Authors: I Siikavuopio, Trine DaleAbstract:Dietary protein ( 25%) influences on the sensory characteristics of green sea urchin (Strongylocentrotus Droebachiensis) gonads were examined in two feeding experiments, both lasting for 60 days. Gonad indices and sensory quality were evaluated, and were compared with those of gonads from wild sea urchins. Gonad growth was not significantly affected by dietary protein:carbohydrate ratio. Bitter taste was significantly affected by diet in both experiments, sweet taste was significantly affected by diet in only one experiment, whereas the taste attributes old/stale, metal/sour and aftertaste were not significantly affected by diet in either experiment. There was increased intensity of bitter taste with increased dietary protein, and the diet with the lowest protein concentration produced gonads not significantly different in taste from those of wild sea urchins. All sensory attributes related to texture (granularity, firmness, and melting) were affected by diet. Gonads from urchins given the diet with the lowest protein content did not differ significantly from those of wild sea urchins, but there was no consistent relationship between dietary protein and texture attributes.
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Effects of carbon dioxide exposure on feed intake and gonad growth in green sea urchin, Strongylocentrotus Droebachiensis
Aquaculture, 2007Co-Authors: Sten I. Siikavuopio, Trine Dale, Atle Mortensen, Atle FossAbstract:Abstract The effects of carbon dioxide (CO 2(aq) ) on gonad growth and feed intake in green sea urchin, Strongylocentrotus Droebachiensis , were examined. Adult sea urchins with a mean (S.D.) live weight of 50.0 (11.2) g were exposed to two levels of carbon dioxide (CO 2(aq) ), (1.1 (control) and 18.1 mg l − 1 ), for 56 days at 6.0 °C and 33‰. Gonad growth was significantly reduced in the high CO 2 concentration group compared to the control group. In the high carbon dioxide treatment, gonad growth was 67% less than the control treatment. Weekly feed intake and total feed consumption were significantly reduced in the high concentration group. The reduction in gonad growth was attributed to a decrease in feed intake and impaired feed conversion efficiency. The present study demonstrates that adult green sea urchins show low tolerance to increased carbon dioxide levels, and are unable to maintain high gonad growth facing such conditions.
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Effects of hypoxia on feed intake and gonad growth in the green sea urchin, Strongylocentrotus Droebachiensis
Aquaculture, 2007Co-Authors: Sten I. Siikavuopio, Trine Dale, Atle Mortensen, Atle FossAbstract:Abstract The effects of oxygen content on gonad growth and feed intake in “green sea urchin”, Strongylocentrotus Droebachiensis, were examined. Adult sea urchins with a mean (S.D.) live weight of 51.0 (12.2) g were reared at oxygen levels of 4.0, 6.0 (hypoxia) and 9.5 mg l− 1 (normoxia), for 54 days at 8.0 °C and 33‰. Gonad growth and total food consumption were significantly higher in the control group (normoxia) compared with the hypoxic groups at the end of the experiment. Weekly feed intake and total feed consumption were significantly reduced in the two hypoxic groups. The reduction in gonad growth was attributed to a decrease in feed intake and impaired food conversion efficiency. Overall, our findings suggest that adult green sea urchins show low tolerance to hypoxia, and are unable to maintain high gonad growth facing such conditions.
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the effects of stocking density on gonad growth survival and feed intake of adult green sea urchin Strongylocentrotus Droebachiensis
Aquaculture, 2007Co-Authors: Sten I. Siikavuopio, Trine Dale, Atle MortensenAbstract:Abstract In this study the effects of different stocking densities on survival, gonad growth and feed intake in adult green sea urchin ( Strongylocentrotus Droebachiensis ) were examined. Two size groups of sea urchins with respective initial mean weight of 45 g (S) and 70 g (L) were used. The experiments were carried out in 755 l plastic tanks divided into chambers by vertical fibreglass lamellae. In the two experiments stocking densities of 6, 12, 14 and 16 kg m − 2 (Exp I) and 3, 6 and 8 kg m − 2 (Exp II) were used. Sea urchins reared individually in compartmentalised raceways were used as controls in both experiments. All groups were fed a formulated moist feed ad libitum for 60 days at 8 °C (± 0.5). Mortality was observed in all groups, except for the control group and the lowest density group of large sea urchins (3 kg m − 2 , L). Both mortality and occurrence of injuries increased significantly with increasing stocking density in both experiments and for both size groups. In the highest density groups mortality was 60% (L) and 80% (S). There was a significant increase in gonad index during the experimental period in both experiments. Increased stocking density had a significantly negative effect on gonad growth in both size groups while feed intake was unaffected. The results show that adult S. Droebachiensis can maintain high survival rate and high gonad growth at stocking densities up 6 kg m − 2 in holding facilities of the design used in the present study.
Christopher M Pearce - One of the best experts on this subject based on the ideXlab platform.
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co culturing green sea urchins Strongylocentrotus Droebachiensis with mussels mytilus spp to control biofouling at an integrated multi trophic aquaculture site
Aquaculture, 2016Co-Authors: Andrea M Sterling, Stephen F Cross, Christopher M PearceAbstract:Abstract In a field study, five different stocking densities ( i . e . 0, 30, 60, 90, 120 ind. net − 1 or 0, 2.46, 4.91, 7.37, 9.82 ind. m − 2 ) of adult green sea urchins ( Strongylocentrotus Droebachiensis ) were randomly assigned to 30 predator-exclusion nets ( i . e . n = 6) around cultured mussels ( Mytilus spp.) to test the effect of urchin density on biofouling intensity (percent net occlusion) and urchin/mussel growth. After 174 days of culture, nets in all treatments containing sea urchins were significantly less fouled than those in the control treatment without urchins. Fouling intensities on nets with the two highest stocking densities of urchins (90 and 120 ind. net − 1 ) were approximately 40% less than that on nets with urchins held at the lowest stocking density (30 ind. net − 1 ) and 45% less than that on nets without urchins. The differences in fouling intensity among nets with 60, 90, and 120 ind. net − 1 were not statistically significant. While fouling was significantly reduced in the presence of urchins compared to the control treatment with no urchins, it was not completely eliminated since they were only able to access the inside surface of the nets. Sea urchin somatic and gonad growth declined with increasing stocking density, but there was no significant difference in mussel growth at the different urchin stocking densities. Mussels and sea urchins can be successfully co-cultured with no food input, but there may be a trade-off between the effectiveness of biofouling control and sea urchin growth. Statement of relevance This paper examined the use of sea urchins ( Strongylocentrotus Droebachiensis ) to mitigate biofouling in mussel ( Mytilus spp.) aquaculture and the effect of sea urchin density on biofouling coverage and mussel growth. Treatments containing sea urchins showed significantly less fouling than a control treatment without urchins. Urchin density had no significant effect on mussel growth.
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ingestion rate absorption efficiency oxygen consumption and fecal production in green sea urchins Strongylocentrotus Droebachiensis fed waste from sablefish anoplopoma fimbria culture
Aquaculture, 2014Co-Authors: Lindsay C Orr, Daniel L Curtis, Stephen F Cross, Helen Gurneysmith, Alynn Shanks, Christopher M PearceAbstract:Abstract The ability of the green sea urchin (Strongylocentrotus Droebachiensis) to consume and subsequently reduce the organic content of sablefish (Anoplopoma fimbria) culture waste was assessed and properties influencing the dispersal of fecal pellets egested by the sea urchins were quantified in laboratory trials. Ingestion rate, absorption efficiency, and oxygen uptake in sea urchins and the shape, size, and settling velocity of fecal pellets were determined for individuals fed sablefish waste or a natural control diet (giant kelp, Macrocystis pyrifera). Results showed that S. Droebachiensis consumes sablefish waste at a dry weight ingestion rate of 0.43 ± 0.039 g individual− 1 d− 1 and absorbs 40 ± 4.84% (mean ± SE) of the organic material ingested, with no significant (P
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a comparison of three land based containment systems for use in culturing green sea urchins Strongylocentrotus Droebachiensis muller echinodermata echinoidea
Aquaculture Research, 2006Co-Authors: Tara L Daggett, Christopher M Pearce, Shawn M C RobinsonAbstract:Worldwide, most sea-urchin populations are in decline. Future market demands will likely be met through aquaculture, which may consist of gonad enhancement of wild-caught sea urchins. In this context, we examined three land-based containment systems for suitability in maintaining commercial-size green sea urchins (Strongylocentrotus Droebachiensis). Mortality rate, gonad quantity, gonad quality (colour, brightness, firmness, texture) and cleaning efficiency associated with each containment system were the criteria for comparing the effectiveness of the systems (large raceways, small raceways and washtub tanks). After 6 weeks, urchins maintained in large raceways displayed significantly higher mortality rates than urchins maintained in either the small raceways or washtub tanks (mean±SD: 24.3±10.4%, 8.0±3.5% and 4.3±1.5% respectively). Significant differences in cleaning time were detected among the three systems with washtub tanks requiring significantly more cleaning time (0.11±0.02 min urchin[superscript [-]1]) than the other two systems and large raceways requiring significantly less cleaning time (0.06±0.02 min urchin[superscript [-]1]) than the other two systems. No significant differences in gonad characteristics were detected among the three containment systems. Because of the higher mortality rate in the large raceways and the increased cleaning time required for the washtub tanks, the small raceways were considered to be the best of the three systems tested.
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optimizing prepared feed ration for gonad production of the green sea urchin Strongylocentrotus Droebachiensis
Journal of The World Aquaculture Society, 2002Co-Authors: Christopher M Pearce, Tara L Daggett, Shawn M C RobinsonAbstract:Adult green sea urchins Strongylocentrotus Droebachiensis were fed three different quantities (0.25, 0.50, 1.00% body weight/d) of a prepared feed during a 12-wk experiment to determine the effect of food ration on gonad quantity and quality. A diet of kelp, Laminaria longicruris and/or L. digitata, fed at satiation (3% body weight/d) and urchins taken from the wild at the beginning and end of the experiment served as controls. Urchins fed prepared feed or kelp increased their percent gonad yield significantly over the experimental period. Affer 12 wk, individuals fed the prepared diet at 0.50 or 1.00% body weighffd had significantly higher percent gonad yields (mean ± SEM: 23.5 ± 0.6% and 23.4 ± 0.7%, respectively) than urchins fed at 0.25% body weight/d (18.0 ± 1.0%) or control animals given kelp (18.3 ± 0.8%). There was no significant difference in gonad yield between the 0.50 and 1.00% feeding levels. All feeding treatments had significantly higher percent gonad yields than urchins sampled from the wild at the end of the experiment that had recently spawned (2.8 ± 0.5%). There was no significant difference in gonad taste among urchins fed the prepared diet at 0.25% body weight/d, those given kelp, or those collected from the wild at the end of the experiment (good to very good ratings), but all of these treatments had significantly better tasting gonads than urchins given the prepared feed at 0.50 or 1.00% body weight/d (satisfactory ratings). Gonad taste rating of urchins fed a prepared diet was dependent on ration with greater feed amounts leading to worse tasting gonads (linear regression: r2= 0.68, P < 0.01). Gonad color, texture, and firmness did not differ significantly among any of the feed ration treatments or kelp control. Results suggest that the best ration for prepared feed would be 0.50% body weightld since this would optimize gonad yield while minimizing feed costs. Further research on prepared feeds is required to optimize both gonad color and taste.
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effect of macroalgae microbial films and conspecifics on the induction of metamorphosis of the green sea urchin Strongylocentrotus Droebachiensis mu ller
Journal of Experimental Marine Biology and Ecology, 1991Co-Authors: Christopher M Pearce, Robert Eric ScheiblingAbstract:Abstract Various macroalgae, microbial films, and conspecifics were tested for their potential to induce metamorphosis of larvae of the green sea urchin Strongylocentrotus Droebachiensis (Mu¨ller) in the laboratory. The percentage of larvae that metamorphosed varied with macroalgal species: coralline and noncoralline red algae induced the greatest percent metamorphosis, fucoid and laminarian algae the lowest. Percent metamorphosis in response to acrylic plastic plates with marine microbial films was higher when films were developed in light than in dark and increased with the age of the film. Filmed substrata taken from the intertidal zone of a rocky shore induced a high percentage of larvae to metamorphose, sand collected subtidally did not. Adult urchins, adult-conditioned seawater, adult faecal matter, and recently settled juveniles did not induce metamophosis of larvae, suggesting that a conspecific cue was not involved. These laboratory findings suggest that settlement of S. Droebachiensis in the field may not be very selective, although other factors influencing larval supply and transport in the water column and along the boundary layer may result in differential settlement among different micro- and macrohabitats.
