The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform

Miles D Lamare - One of the best experts on this subject based on the ideXlab platform.

  • Carotenoid composition of a New Zealand (Evechinus chloroticus) and an Australian (Heliocidaris erythrogramma) sea urchin in relation to gonad colour
    Aquaculture Research, 2018
    Co-Authors: Jodi L. Brewster, Miles D Lamare, Daniel J. Garama, Alan Carne
    Abstract:

    Sea urchins are commercially harvested for their edible gonads, also known as roe or uni. Most species, particularly those from the Northern hemisphere are reported to exhibit limited variation in gonad colour, which is proposed to be due to carotenoid pigments. The commercially harvested species from New Zealand, Evechinus chloroticus, and from Australia, Heliocidaris erythrogramma, however, exhibit considerable gonad colour variation, ranging from a culinary desirable light yellow/orange to an undesirable brown. Gonads from E. chloroticus and H. erythrogramma were characterized spectrophotometrically and the carotenoid content extracted and analysed by reversed‐phase high‐performance liquid chromatography. The main carotenoid found in the gonads of both species was 9′‐cis‐echinenone, with lower levels of all‐trans‐echinenone, lutein and isozeaxanthin. Carotenoid composition contributed to the yellow/orange colour components of the gonads, but was not correlated with the darker roe coloration observed in some E. chloroticus individuals. Our results highlight important considerations relating sea urchin gonad coloration to carotenoid content and as such will provide useful information for the future aquaculture and processing of these two species.

  • Maternal antioxidant provisioning mitigates pollutant-induced oxidative damage in embryos of the temperate sea urchin Evechinus chloroticus
    Scientific reports, 2017
    Co-Authors: Kathryn N. Lister, Miles D Lamare, David J. Burritt
    Abstract:

    One mechanism of pollution resistance in marine populations is through transgenerational plasticity, whereby offspring capacity to resist pollution reflects parental exposure history. Our study aimed to establish correlations between oxidative stress biomarkers and key reproductive fitness parameters in the temperate sea urchin Evechinus chloroticus following exposure to dietary polycyclic aromatic hydrocarbons (PAHs). PAH-exposed adults exhibited total gonad tissue concentrations of PAHs in excess of 4 and 5 times baseline levels, for females and males respectively. Antioxidant enzymes were upregulated and oxidative lipid and protein damage to gonad tissues occurred. In addition, early stage offspring reflected maternal antioxidant status, with progeny derived from exposed females demonstrating significantly higher baselines than those derived from control females. Maternal exposure history enhanced the capacity of embryos to minimise oxidative damage to lipids and proteins following exposure to additional PAHs, but provided less of an advantage in protection against oxidative DNA damage. Abnormal embryonic development was largely independent of oxidative damage, remaining high in all embryo populations regardless of parental PAH-history. Overall, results document evidence for maternal transfer of antioxidant potential in E. chloroticus, but imply that a short-term inherited resilience against oxidative stress may not necessarily translate to a fitness or survival gain.

  • Dietary pollutants induce oxidative stress, altering maternal antioxidant provisioning and reproductive output in the temperate sea urchin Evechinus chloroticus
    Aquatic toxicology (Amsterdam Netherlands), 2016
    Co-Authors: Kathryn N. Lister, Miles D Lamare, David J. Burritt
    Abstract:

    Evidence is growing to suggest that the capacity to withstand oxidative stress may play an important role in shaping life-history trade-offs, although little is known on the relationship in broadcast spawning marine invertebrates. In this group, variation in gamete quantity and quality are important drivers of offspring survival and successful recruitment. Therefore the provisioning of eggs with antioxidants may be an important driver of life history strategies because they play a critical role in preventing damage from reactive oxygen species to macromolecules. In this study, a suite of oxidative stress biomarkers was measured in the gonads and eggs of the sea urchin Evechinus chloroticus exposed to polycyclic aromatic hydrocarbons (PAHs). Links between oxidative stress markers and core components of fitness including fecundity, gamete quality and maternal transfer of antioxidants were assessed. Experimental induction of oxidative stress was achieved via exposure to a mix of four PAHs over a 21-day period. In PAH exposed individuals, we observed a significant upregulation of the antioxidant defence and detoxification enzymes SOD, CAT, GR, GPx and GST, as well as a greater pool of the non-enzymatic antioxidant glutathione in gonad tissue and eggs. In contrast, glutathione redox status was not affected by PAH exposure, with the percentage of reduced glutathione remaining at approximately 80% in both gonad tissue and released eggs. PAH-exposed adults experienced greater than three- and five-fold increases in oxidative protein and lipid damage, respectively, in gonad tissue. In contrast, eggs maintained low levels of damage, not differing from baseline levels found in eggs released from PAH-naive mothers. PAH exposure also resulted in a 2-fold reduction in fecundity of reproductively mature females but no significant alteration to egg diameter. Although PAH-exposed females released fewer eggs, successful fertilisation of those eggs was slightly enhanced with average rates ranging from 90-99% in comparison to 76-90% in control eggs. Early-stage offspring reflected maternal antioxidant status with populations derived from PAH-exposed mothers demonstrating significantly higher antioxidant levels than those derived from PAH-naive mothers. This maternally inherited protection enhanced the capacity of embryos to minimise oxidative damage to lipids and proteins during early development but, despite this, did not reduce the proportion of morphological abnormalities in the population. Overall, these findings indicate that when faced with short-term contaminant stress E. chloroticus has the capacity to trade high reproductive output during a spawning event for a greater antioxidant investment in eggs. However, this production of potentially more resilient offspring did not translate to a fitness gain, at least for the early larval stages in the present experimental conditions.

  • Variation in sunscreen compounds (mycosporine‐like amino acids) for marine species along a gradient of ultraviolet radiation transmission within doubtful sound, New Zealand
    New Zealand Journal of Marine and Freshwater Research, 2004
    Co-Authors: Miles D Lamare, Mike F. Barker, Michael P. Lesser, Thomas M. Barry, Kate B. Schimanski
    Abstract:

    Abstract We examined the response of four species of New Zealand marine algae (Ecklonia radiata, Apophlaea lyallii, Rhodymenia spp., Ulva lactuca) and a sea urchin (Evechinus chloroticus) to spatial variation in ultraviolet radiation (UV‐R) by examining the concentration of UV‐R absorbing compounds known as mycosporine‐like amino acids (MAAs). The purpose was to understand how, and the degree to which, local marine species could potentially respond to any future increases in incident UV‐R in the New Zealand marine environment. The research was undertaken in Doubtful Sound, where we observed a gradient of water column UV‐R transmission along the 40 km length of the fiord. We examined spatial differences in MAAs along the UV‐B gradient in the macrophytes and temporal changes in MAAs in sea urchin gonads. Among the algae, thallus MAA concentrations (nmol mg–1 protein) ranged from 12.5 to 87.8 in E. radiata, from 433.1 to 1446.4 in A. lyallii, 12.7 to 103.4 in Rhodymenia spp., but were not detected in U. lact...

  • Reproductive sources and sinks within a sea urchin, Evechinus chloroticus, population of a New Zealand fjord
    Marine Ecology Progress Series, 2003
    Co-Authors: Stephen R. Wing, Mark T. Gibbs, Miles D Lamare
    Abstract:

    We examined population structure of New Zealand sea urchins Evechinus chloroticus across the Doubtful-Thompson Sound complex, a fjord with a large influx of freshwater, a low salin- ity surface layer and a mean estuarine circulation. Measurements of abundance, growth, gonad development and larval settlement were collected at 9 sites. We observed large differences in each of these vital population parameters among sites. The highest growth rates and gamete production occurred at the entrances of the fjord. We used 3 alternative growth models to test whether the spa- tial pattern in growth rates was robust. Variability in growth among sites likely reflected differences in nutritional history, as indicated by the Aristotle's lantern index. Size distributions taken 2 yr apart at each of the 9 sites showed that the adult mode was relatively stable in time. As a consequence much of the variance in mean size among sites could be explained by differences in growth rather than in mortality or recruitment. The highest abundance and aggregation of sea urchins occurred at mid-fjord and entrance sites, which coincided with the highest rates of larval settlement and sug- gested limited larval supply elsewhere. The observed spatial patterns in vital rates were used to eval- uate the likely influences of spatial heterogeneity in larval production on larval dispersal patterns within the fjord, based on particle movements within a validated hydrodynamic model. We then tested the sensitivity of these model results to magnitude of wind and rainfall events and duration of larval development. Results from our field observations and modeling studies suggest that the sea urchin population in Doubtful-Thompson Sound is likely composed of distinct areas of reproductive source and sink.

Mary A. Sewell - One of the best experts on this subject based on the ideXlab platform.

  • Effect of acclimation on thermal limits and hsp70 gene expression of the New Zealand sea urchin Evechinus chloroticus
    Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 2020
    Co-Authors: Natalí J. Delorme, Emily J. Frost, Mary A. Sewell
    Abstract:

    Abstract Seawater temperature is projected to increase globally due to climate change, affecting physiological responses, fitness and survival of marine organisms. Thermal tolerance studies are critical to determine the ability of animals to adapt to future environmental conditions. In this study, we aimed to determine if the thermal limits of the New Zealand Evechinus chloroticus would shift with animal's thermal history. We tested the effect of six thermal regimes on the righting ability, temperature of loss of righting (TLOR), median lethal temperature (LT50), lethal temperature (LT) and the gene expression of the heat shock protein 70 (hsp70) of the New Zealand sea urchin E. chloroticus when exposed to a thermal shock of 1 °C day−1 (duration of 7–16 days depending on the treatment). Treatments consisted of laboratory acclimation for one and four weeks to 18 °C and 24 °C (mean winter (15 °C) and summer temperature (21 °C) + 3 °C of warming, respectively), compared to non-acclimated sea urchins collected during winter (14.6 °C) and summer seasons (20.4 °C). Thermal history did not have a significant effect on the righting ability of E. chloroticus (TLOR ranged between 28 and 29 °C for all treatments) and LT50 (ranged between 29 and 30 °C for all treatments). However, LT of E. chloroticus collected during winter season was significantly lower than animals acclimated for one week at 18 °C. Maximum expression of hsp70 mRNA (Tmax) was observed at around 27–28 °C regardless of treatment; however, relative hsp70 mRNA levels were significantly higher in animals acclimated for four weeks at 24 °C. Despite proving to be a thermotolerant species with LTs around 30 °C, E. chloroticus was unable to increase thermal tolerance and Tmax when acclimated to high temperatures, suggesting that E. chloroticus may have a limited adaptive capacity to modify its phenotype; however, evolutionary adaptations may allow E. chloroticus to adapt to future ocean temperatures.

  • Genotype-by-environment interactions during early development of the sea urchin Evechinus chloroticus
    Marine Biology, 2016
    Co-Authors: Natalí J. Delorme, Mary A. Sewell
    Abstract:

    The increase in seawater temperature due to anthropogenic climate change is likely to affect population persistence and changes in distributional ranges of marine species. Adaptation to warmer environmental conditions will be determined by the presence of tolerant genotypes within a population. The present study determined the genotype-by-environment (G × E) interactions during early development of the New Zealand sea urchin Evechinus chloroticus cultured at 18 °C (mean annual temperature), 21 °C (ambient summer temperature) and 24 °C (+3 °C above ambient summer temperature). The experiment was performed in 3 experimental blocks using gametes from 3 males and 3 females crossed in all combinations (North Carolina II cross-breeding design), resulting in 9 families per experimental block (i.e., total of 27 families). Differences between female and male identities were quantified during cleavage and gastrulation: Reaction norms (i.e., interaction plots) showed a clear G × E interaction, with some genotypes performing better than others at high temperatures. Heritability during gastrulation was 0.51, indicating that 51 % of the variability corresponds to genetic variation. Overall, the present study shows that seawater temperature has a negative effect on early development of E. chloroticus; however, there are resilient genotypes in the studied population that could provide the genetic potential to adapt to future ocean conditions.

  • Effects of warm acclimation on physiology and gonad development in the sea urchin Evechinus chloroticus.
    Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 2016
    Co-Authors: Natalí J. Delorme, Mary A. Sewell
    Abstract:

    The physiology of the New Zealand sea urchin Evechinus chloroticus was evaluated through feeding, respiration, growth and gonad growth in adult animals acclimated for 90days at 18°C (annual mean temperature) and 24°C (ambient summer temperature (21°C) +3°C). Measured parameters with representative rates of assimilation efficiency were used to calculate scope for growth (SfG) for each treatment. All physiological parameters were negatively affected at 24°C, showing a decrease in feeding rate which coincided with negative growth and gonad development at the end of the acclimation period, and a decrease in respiration rate suggesting metabolic depression. Histology of gonad samples after the acclimation period also showed no gametic material in animals acclimated at 24°C. All animals acclimated at 24°C had negative growth, differing from the calculated SfG which indicated that the animals had sufficient energy for production. The results suggest that calculated SfG in echinoderms should be used together with actual measurements of growth in individuals as, by itself, SfG may underestimate the actual effect of ocean warming when animals are exposed to stressful conditions. Overall, considering the total loss of reproductive output observed in E. chloroticus at higher temperatures, an increase in seawater temperature could dramatically influence the persistence of northern populations of this species, leading to flow-on effects in the subtidal ecosystem.

  • Comparative ultrastructure of spermatozoa from two regular and two irregular New Zealand echinoids
    Invertebrate Biology, 2015
    Co-Authors: Michael E. Hudson, Adrian P Turner, Mary A. Sewell
    Abstract:

    Spermatozoa from four species of echinoids found in New Zealand had morphological characteristics typical of other echinoids, including a conical sperm head with an acrosome-capped nucleus, a midpiece, and a single long flagellum. The spermatozoa of Fellaster zelandiae, Echinocardium cordatum, Evechinus chloroticus, and Centrostephanus rodgersii also showed statistically significant differences in species-specific morphological characteristics. Evechinus chloroticus showed the most variable sperm morphology. The irregular urchins (F. zelandiae and E. cordatum) had short, wide sperm heads (head length:width ratios 2.93:1 & 2.97:1, respectively) with a long acrosome complex, while the regular urchins (E. chloroticus and C. rodgersii) had longer, narrower heads with a short acrosome complex (ratios 5.29:1 & 3.37:1). Spermatozoa of E. cordatum from the New Zealand population shared more characteristics with those of conspecifics from the Sea of Japan than those of conspecifics from the Baltic, reflecting the membership of the former two populations in a distinct Pacific clade. Volumetric calculations showed no evidence of phylogenetic grouping. Mitochondria of E. chloroticus spermatozoa were less than half the volume of those of C. rodgersii and E. cordatum, and those of F. zelandiae were intermediate in volume. These volume measurements will be useful in physiological studies of sperm performance and quality.

  • Differences in population connectivity of a benthic marine invertebrate Evechinus chloroticus (Echinodermata: Echinoidea) across large and small spatial scales
    Conservation Genetics, 2015
    Co-Authors: Meredith M. Nagel, Mary A. Sewell, Shane D. Lavery
    Abstract:

    Marine organisms with a planktonic larval stage have the potential to be transported substantial distances, with the distance travelled depending on factors such as pelagic larval duration (PLD) and physical factors such as ocean currents and geographical barriers. The endemic New Zealand sea urchin, Evechinus chloroticus, is found throughout the North and South Islands, and with a PLD of approximately 30 days, is expected to show strong connectivity among all populations. Population connectivity and genetic differentiation were examined over both a geographically broad scale, throughout New Zealand, and on a fine scale (within the Hauraki Gulf on the North Island). Significant genetic differentiation was revealed through analysis of mitochondrial COI sequences (FST = 0.096 p 

Adnan A. Bekhit - One of the best experts on this subject based on the ideXlab platform.

  • PHNQ from Evechinus chloroticus Sea Urchin Supplemented with Calcium Promotes Mineralization in Saos-2 Human Bone Cell Line.
    Marine drugs, 2020
    Co-Authors: Yakun Hou, Alan Carne, Michelle Mcconnell, Sonya Mros, Elena A. Vasileva, Natalia P. Mishchenko, Keegan Burrow, Ke Wang, Adnan A. Bekhit
    Abstract:

    Polyhydroxylated naphthoquinones (PHNQs), known as spinochromes that can be extracted from sea urchins, are bioactive compounds reported to have medicinal properties and antioxidant activity. The MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cell viability assay showed that pure echinochrome A exhibited a cytotoxic effect on Saos-2 cells in a dose-dependent manner within the test concentration range (15.625–65.5 µg/mL). The PHNQ extract from New Zealand sea urchin Evechinus chloroticus did not induce any cytotoxicity within the same concentration range after 21 days of incubation. Adding calcium chloride (CaCl2) with echinochrome A increased the number of viable cells, but when CaCl2 was added with the PHNQs, cell viability decreased. The effect of PHNQs extracted on mineralized nodule formation in Saos-2 cells was investigated using xylenol orange and von Kossa staining methods. Echinochrome A decreased the mineralized nodule formation significantly (p < 0.05), while nodule formation was not affected in the PHNQ treatment group. A significant (p < 0.05) increase in mineralization was observed in the presence of PHNQs (62.5 µg/mL) supplemented with 1.5 mM CaCl2. In conclusion, the results indicate that PHNQs have the potential to improve the formation of bone mineral phase in vitro, and future research in an animal model is warranted.

  • In vitro antioxidant and antimicrobial activities, and in vivo anti-inflammatory activity of crude and fractionated PHNQs from sea urchin (Evechinus chloroticus).
    Food chemistry, 2020
    Co-Authors: Yakun Hou, Alan Carne, Michelle Mcconnell, Sonya Mros, Adnan A. Bekhit, Kikuko Amagase
    Abstract:

    Abstract This study investigated the bioactivities of polyhydroxyl-1,4-naphthoquinone (PHNQ) extracts from Evechinus chloroticus shell waste. PHNQs were extracted from E. chloroticus shells and spines using different solvents and the crude extracts were fractionated by HPLC. The antioxidant activity of the PHNQ extracts were evaluated by the DPPH, ABTS, ORAC and FRAP assays. Ethyl acetate was the best extraction solvent and spine extracts showed better antioxidant activity than shell extracts (p

  • Macroporous resin extraction of PHNQs from Evechinus chloroticus sea urchin and their in vitro antioxidant, anti-bacterial and in silico anti-inflammatory activities
    LWT, 2020
    Co-Authors: Yakun Hou, Alan Carne, Michelle Mcconnell, Sonya Mros, Adnan A. Bekhit
    Abstract:

    Abstract This study investigated the polyhydroxyl-1,4-naphthoquinone (PHNQ) composition and bioactivities of Evechinus chloroticus sea urchin shell and spine waste extracted using the macroporous resins NKA-9, D4020, D4006, and D101. The mineral and protein contents in the shell and spine were found to be 85.21% and 84.14%, 3.85% and 8.96%, respectively. Spine PHNQs extracted using the D4006 resin had the highest total phenolic content (TPC) while the D101 and D4020 resin extracts had a lower TPC (p

  • Extraction, structural characterization and stability of polyhydroxylated naphthoquinones from shell and spine of New Zealand sea urchin (Evechinus chloroticus).
    Food chemistry, 2018
    Co-Authors: Yakun Hou, Alan Carne, Michelle Mcconnell, Elena A. Vasileva, Natalia P. Mishchenko, Adnan A. Bekhit
    Abstract:

    Abstract The extraction of polyhydroxylated naphthoquinone (PHNQ) pigments from the shell and spines of the New Zealand sea urchin Evechinus chloroticus was evaluated using six different macroporous resins as an alternative to using organic solvent extraction alone. Four of the resins evaluated in this study (D4006, D4020, D101 and NKA-9) provided the best extraction of PHNQ pigments in terms of the overall adsorption and desorption of E. chloroticus PHNQ pigments from the resins. Organic solvents alone had a higher yield of PHNQs than the resins. The PHNQ composition was characterised by high-performance liquid chromatography (HPLC) with diode‐array detection and mass spectrometry. Five PHNQ compounds (spinochromes E, B, C, A and echinochrome A), and three aminated PHNQ compounds (spinamine E, echinamines A and B) were identified. The pigments were found to be prone to degradation on exposure to light, with the aminated PHNQ pigments being the least stable.

  • Synthesis of macro and micro porous hydroxyapatite (HA) structure from waste kina (Evechinus chloroticus) shells
    Journal of the Taiwan Institute of Chemical Engineers, 2016
    Co-Authors: Amin Shavandi, Victoria Wilton, Adnan A. Bekhit
    Abstract:

    Abstract The aim of this study was to investigate the conversion of waste kina shells ( Evechinus chloroticus ) into hydroxyapatite (HA, Ca 10 (PO 4 ) 6 (OH) 2 ), while preserving its porous and interconnected structure. The shells were subjected to a pyrolysis process followed by a chemical synthesis step at ambient pressure and at a low temperature of 100 °C under alkaline condition. The obtained HA had a porous structure with large pores ranged 300–500 µm and small pores of 10–20 µm, which is considered beneficial for bone repair materials to ensure blood and nutrient circulation required for bone regeneration. The samples also had high concentrations of magnesium (3.44%) which is an important component of HA used in bone grafting. X-Ray Diffractometer results indicated that a HA layer was formed on the surface of the calcium carbonate structure of the shells. The synthesized HA had no toxicity to the osteoblast cells and the porous and interconnected microstructure of the shells was preserved during an incubation period of 3 days. The obtained HA may have potential applications in bone tissue enegineering.

Phil Bremer - One of the best experts on this subject based on the ideXlab platform.

  • Extraction and analysis of carotenoids from the New Zealand sea urchin Evechinus chloroticus gonads.
    Acta biochimica Polonica, 2012
    Co-Authors: Daniel Garama, Phil Bremer, Alan Carne
    Abstract:

    Sea urchin gonad (roe) is a highly valued food in Japan and North America. Gonad price is strongly influenced by quality, with appearance, especially colour being a major determinant. Previous attempts to extract a carotenoid profile from the New Zealand sea urchin species Evechinus chloroticus have been challenging due to the large amount of lipid present in the gonad. A carotenoid extraction and high performance liquid chromatography (HPLC) analysis method was developed to reduce lipid contamination by incorporating a saponification and lipid cold precipitation in the extraction procedure. This method enabled greater carotenoid purity and enhanced analysis by HPLC. Echinenone was found to be the main carotenoid present in all E. chloroticus gonads. Dark coloured gonads contained higher levels of fucoxanthin/fucoxanthinol, β-carotene and xanthophylls such as astaxanthin and canthaxanthin. This information on the modification and deposition of carotenoids will help in the development of diets to enhance gonad colour.

  • Seasonal changes in the biochemical composition of Evechinus chloroticus gonads (Echinodermata: Echinoidea)
    New Zealand Journal of Marine and Freshwater Research, 2012
    Co-Authors: Wasseela Verachia, Brian E Niven, Mary A. Sewell, Mike F. Barker, Michelle Leus, Phil Bremer
    Abstract:

    Abstract The influence of season, gender and sexual maturity on the biochemical composition (moisture, protein, total lipids, triglycerides, cholesterol, phospholipids, free amino acids, glucose and glycogen) of gonads from the endemic New Zealand sea urchin Evechinus chloroticus was investigated. Gonads were obtained from urchins during the austral autumn, winter, summer and spring, over a 23-month period. Biochemical differences between genders were less pronounced in autumn (March to May) and winter (June to August) when more nutritive cells were present in the gonads, and more distinct over spring (September to November) and summer (December to February) months as the gametogenic cells matured, thus highlighting the importance of assessing testes and ovaries separately during biochemical analysis. Differences in the biochemical composition of testes and ovaries were the least pronounced during autumn, which suggests this will be the best season to harvest E. chloroticus in order to enhance taste and f...

  • Effect of manufactured diets on the yield, biochemical composition and sensory quality of Evechinus chloroticus sea urchin gonads.
    Aquaculture, 2010
    Co-Authors: K Phillips, Mary A. Sewell, Mike F. Barker, Nazimah Hamid, Patrick Silcock, Conor M. Delahunty, A Weaver, S. Then, Phil Bremer
    Abstract:

    Abstract Sea urchins ( Evechinus chloroticus ) were held in sea cages and fed either one of two manufactured diets, or seaweed. Physical (gonad index, maturity index and colour L * a * b *), biochemical (lipids, glycogen, soluble protein, moisture and free amino acids) and sensory characteristics of the gonads from caged and wild sea urchins were measured at the end of a 13- week trial. The gonad index of sea urchins fed the manufactured diet which was highest in protein, was approximately double that of wild sea urchins, and significantly ( p  ≤ 0.05) higher than sea urchins fed seaweed. Gonads from sea urchins fed the manufactured diet highest in protein had significantly ( p  ≤ 0.05) higher glycogen and total free amino acid concentration, and a lower triglyceride concentration than gonads from sea urchins fed seaweed or collected from the wild. Ovaries had a significantly ( p p  ≤ 0.05) differences in the concentration of individual free amino acids between genders and diet. Descriptive analysis carried out using a trained sensory panel reported differences in gonad sensory quality. Ovaries from wild sea urchins were significantly higher for sweet and umami taste, than ovaries from sea urchins fed the manufactured diets, which had a higher rating for bitter taste. Testes from wild sea urchins had a significantly harder texture than testes from sea urchins fed manufactured diets or seaweed. Sweet taste was significantly ( p  ≤ 0.05) positively correlated to glycine concentration in testes but not ovaries, while bitter taste was positively correlated to valine, leucine, and isoleucine concentration in both testes and ovaries. This study demonstrated that diet had a significant influence on the physical, biochemical and sensory characteristics of E. chloroticus gonads, and highlighted the importance of analysing E. chloroticus testes and ovaries separately.

  • Effect of Season on the Sensory Quality of Sea Urchin (Evechinus chloroticus) Roe
    Journal of food science, 2010
    Co-Authors: Kylie Phillips, Mike F. Barker, Nazimah Hamid, Patrick Silcock, Conor M. Delahunty, Phil Bremer
    Abstract:

    :  The influence of season, gender, and reproductive maturity on the sensory properties (appearance, odor, taste, flavor, texture/mouthfeel, and aftertaste) of roe from sea urchins (Evechinus chloroticus) was investigated. A trained sensory panel applied descriptive analysis, with a comprehensive sensory vocabulary of 35 descriptors to analyze sea urchin roe obtained from samples collected during the austral autumn, winter, summer, and spring, over a 2-y period. Sensory differences between genders were less pronounced in autumn (March to May) and winter (June to August) when more nutritive cells were present in the roe, and more pronounced over spring (September to November) and summer (December to February) months as the gametogenic cells matured. Roe from female sea urchins were commonly associated with sulfur odor, bitter taste, and metallic flavor, while roe from the male sea urchins were associated with sweet taste. During autumn, female roe were closest in sensory quality to male roe (least bitter and most sweet compared to other seasons), while there were little differences in sweetness and bitterness of male roe over the 4 seasons. Despite the relative size of the roe being lowest in autumn, it appeared to be the optimum season to harvest E. chloroticus sea urchins to obtain high-quality roe.

  • Characterisation of odour active volatile compounds of New Zealand sea urchin (Evechinus chloroticus) roe using gas chromatography–olfactometry–finger span cross modality (GC–O–FSCM) method
    Food Chemistry, 2010
    Co-Authors: Jun Niimi, Michelle Leus, Nazimah Hamid, Patrick Silcock, Phil Bremer
    Abstract:

    Abstract Sea urchin roe is a high value product; however, previous attempts to market the roe from the New Zealand sea urchin (Evechinus chloroticus) have been unsuccessful due to its inconsistent sensory quality. The current study investigated the odour active volatile profiles of roe from male and female sea urchins, harvested from two locations in New Zealand, using solvent assisted flavour evaporation (SAFE) extracts and a gas chromatography–olfactometry–finger span cross modality (GC–O–FSCM) method. Panellists detected 81 odour active compounds, 18 of which were identified using GC–mass spectrometry (MS). Generalised procrustes analysis (GPA) of the data revealed that there were differences in the volatile profile that were location and gender specific. These differences may have contributed to the inconsistent sensory properties of sea urchin roe. The differences in volatile profiles between sea urchin populations and genders must be appreciated before developing effective strategies to produce consistent sea urchin roe quality.

Stephen R. Wing - One of the best experts on this subject based on the ideXlab platform.

  • Overthrowing a regime shift: displacement of sea urchins by abalone in a kelp forest ecosystem
    Ecosphere, 2015
    Co-Authors: Stephen R. Wing, Lucy Jack, Yuki Fujita
    Abstract:

    Interactions among sea urchin and abalone populations provide an important mechanism for maintaining segregation of habitat use at small spatial scales within kelp forest ecosystems. Here we provide evidence from a long-term study of the sea urchin, Evechinus chloroticus, and the abalone, Haliotis iris, populations in a pristine rocky harbor of Stewart Island, in southern New Zealand. Between 1998 and 2014 we observe declines in density of abalone within fished regions of the Inlet and a coincident increase in density of sea urchins. In these regions, sea urchins progressively invaded the shallow (0–3 m) depth stratum formally occupied by abalone and dense, multi-layered stands of macroalgae. Formation of the Ulva Island Marine Reserve in 2004 released abalone populations from fishing mortality, resulting in population increases within the shallow water depth stratum. Here we observed declines in sea urchin density as the growing abalone population displaced sea urchins from the shallow water habitats. Th...

  • Decadal-scale dynamics of sea urchin population networks in Fiordland, New Zealand are driven by juxtaposition of larval transport against benthic productivity gradients
    Marine Ecology Progress Series, 2009
    Co-Authors: Stephen R. Wing
    Abstract:

    Size structure among 3 genetically distinct populations of the sea urchin Evechinus chloroticus was investigated between 1998 and 2007 at 22 study sites distributed in the Fiordland region in southwestern New Zealand. Data on morphology and abundance of the common kelp Ecklonia radiata was used as an indicator of the availability of high-quality food among sites. Habi- tats close to the fjord entrances with relatively high density of E. radiata (0.5 ± 0.1 (SE) to 1.2 ± 0.2 m -2 ) supported E. chloroticus subpopulations with large average test diameters among years (94 ± 9.3 to 120 ± 2.8 mm) and stable adult modes across the 10 yr period. In contrast those subpopulations in inner fjord habitats with lower E. radiata abundance (0 to 0.4 ± 0.1 m -2 ) were characterised by smaller average test diameters (64.3 ± 6.5 to 103.4 ± 1.7 mm) and frequent large pulses of newly emergent juveniles (

  • Reproductive sources and sinks within a sea urchin, Evechinus chloroticus, population of a New Zealand fjord
    Marine Ecology Progress Series, 2003
    Co-Authors: Stephen R. Wing, Mark T. Gibbs, Miles D Lamare
    Abstract:

    We examined population structure of New Zealand sea urchins Evechinus chloroticus across the Doubtful-Thompson Sound complex, a fjord with a large influx of freshwater, a low salin- ity surface layer and a mean estuarine circulation. Measurements of abundance, growth, gonad development and larval settlement were collected at 9 sites. We observed large differences in each of these vital population parameters among sites. The highest growth rates and gamete production occurred at the entrances of the fjord. We used 3 alternative growth models to test whether the spa- tial pattern in growth rates was robust. Variability in growth among sites likely reflected differences in nutritional history, as indicated by the Aristotle's lantern index. Size distributions taken 2 yr apart at each of the 9 sites showed that the adult mode was relatively stable in time. As a consequence much of the variance in mean size among sites could be explained by differences in growth rather than in mortality or recruitment. The highest abundance and aggregation of sea urchins occurred at mid-fjord and entrance sites, which coincided with the highest rates of larval settlement and sug- gested limited larval supply elsewhere. The observed spatial patterns in vital rates were used to eval- uate the likely influences of spatial heterogeneity in larval production on larval dispersal patterns within the fjord, based on particle movements within a validated hydrodynamic model. We then tested the sensitivity of these model results to magnitude of wind and rainfall events and duration of larval development. Results from our field observations and modeling studies suggest that the sea urchin population in Doubtful-Thompson Sound is likely composed of distinct areas of reproductive source and sink.

  • Reproduction of the sea urchin Evechinus chloroticus (Echinodermata: Echinoidea) in a New Zealand fiord
    New Zealand Journal of Marine and Freshwater Research, 2002
    Co-Authors: Miles D Lamare, Mike F. Barker, Paul E. Brewin, Stephen R. Wing
    Abstract:

    Abstract The reproductive cycle of Evechinus chloroticus (Val.) was examined at three (outer, mid, and inner) sites in Doubtful Sound, Fiordland over a 3‐year period. We found that sea urchins from all three populations had an annual gametogenic cycle, the timing of which was temporally and spatially consistent. Inter‐individual variation in the gametogenic cycle was noted within each population, however, initiation of gametogenesis was generally synchronous among males and females and among sites, occurring in May/June. Strong asynchrony in gamete maturation was observed in Deep Cove, occurring in males 4–5 months earlier than females. Spawning occurred in December at the inner and mid fiord sites, while occurring in January at the outer fiord site. Reproductive potential (maximum gonad index) and output (weight of gametes released/g of animal/year) varied spatially and temporally, where there was a consistent decreasing trend in reproductive potential and output with increasing distance away from the fi...