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Simple Summary: Differing light color environments can have inhibitory and promotional effects on the growth of aquatic life. We aimed to determine the optimal light color composition that promotes the growth and development of Tripneustes gratilla and provide valuable basic insights for the large-scale cultivation of sea urchins in China. The sea urchins exhibited improved growth and feeding performance under blue and green light conditions, and the sea urchin organisms were in better physiological condition under blue light. In contrast, red light had a significant inhibitory effect on the feeding and growth rates of the sea urchins. These differences may differentially affect the development and reproduction of sea urchins, with sea urchins being more suited to growth and development under blue light, followed by white and green light, and not suited to development and reproduction under red light. Studying the impact of light color on the digestive and antioxidant processes of sea urchins is essential to decrease physiological stress and enhance the well-being of farmed sea urchins. To study the effects of light color on sea urchin (Tripneustes gratilla), blue light (B, λ450nm), yellow light (Y, λ585–590nm), red light (R, λ640nm), green light (G, λ510nm), white light (W, λ400–780nm), and darkness (H) groups were established in a recirculating seawater aquaculture system. Six different LED light color treatment groups with a photoperiod of 12 L:12 D were tested for 30 days to investigate the effects of different light colors on the feeding, growth, and enzyme activities of T. gratilla (142.45 ± 4.36 g). We found that using different LED light colors caused significantly different impacts on the feeding, growth, and enzyme activity of T. gratilla. Notably, the sea urchins in group B exhibited better growth, with a weight gain rate of 39.26%, while those in group R demonstrated poorer growth, with a weight gain rate of only 26%. The feeding status differed significantly (p < 0.05) between groups B and R, with group B consuming the highest daily intake (6.03 ± 1.69 g) and group R consuming the lowest (4.54 ± 1.26 g). Throughout the three phases, there was no significant change in the viability of the α-amylase (p > 0.05). Conversely, the pepsin viability significantly increased (p < 0.05) in group B. The lipase viability consistently remained at the lowest level, with no notable differences between group W and group B. In group R, both the α-amylase and pepsin viabilities remained lower, whereas the lipase viability was noticeably greater in each phase than in group B (p < 0.05). Among the antioxidant enzymes, group R exhibited a trend of initial increase followed by decreases in catalase, superoxide dismutase, and glutathione peroxidase activities, particularly during the third stage (15–30 days), during which a significant decrease in antioxidant enzyme activity was observed (p < 0.05). Taken together, these findings suggest that blue light positively affects the growth, feeding, digestion, and antioxidant capacity of T. gratilla in comparison with those in other light environments, whereas red light had an inhibitory effect. Furthermore, T. gratilla is a benthic organism that lives on shallow sandy sea beds. Thus, as short wavelengths of blue and green light are more widely distributed on the seafloor, and long wavelengths of red light are more severely attenuated on the seafloor, shorter wavelengths of light promote the growth of bait organisms of sea urchins, which provide better habitats for T. gratilla. [ABSTRACT FROM AUTHOR]

One new flavonoid derivative flavoside A (1), one new 5-hydroxyanthranilic acid derivative crassilin (2), along with the known angucyclinone PD116740 (3) and oxachelin (4), was isolated from the EtOAc extract of the fermentation broth of the sea urchin (Anthocidaris crassispina)-derived actinobacterium, Streptomyces sp. HD01. The structures of these compounds were established on the basis of their HR-ESI-MS and NMR spectroscopic data. All of these compounds were assessed for their antibacterial activity. [ABSTRACT FROM AUTHOR]

Reliable methods of tracing the geographical origin of sea urchin are urgently needed for food safety and consumer health. To the best of our knowledge, the present study was the first attempt to trace the geographic origins of sea urchin by using stable isotope techniques. The δ 13C, δ 15N and δ 18O values from the gonad and spine of sea urchins collected from five locations were analyzed. From the gonad samples, the δ 13C values ranged from −22.07‰ to −18.37‰, the δ 15N values ranged from 6.59‰ to 9.99‰, and the δ 18O values ranged from 17.64‰ to 27.19‰. From the spine samples, the δ 13C values ranged from −5.43‰ to −3.57‰, the δ 15N values ranged from 7.95‰ to 13.66‰, and the δ 1 8O values ranged from 33.99‰ to 40.15‰. The δ 13C and δ 15N values from the gonads differed significantly among samples from different geographic origins, but the δ 1 8O values did not differ. The δ 15N and δ 18O values from the spines differed significantly among samples from different geographic origins, but the δ 13C values did not differ. Both quadratic discriminant analysis (QDA) and the k-nearest neighbor (KNN) methods yielded low recognition of the δ 13C, δ 15N, and δ 18O values from the gonad samples. However, higher accuracy was obtained using the stable isotope values from the spine samples combined with QDA or KNN methods. Moreover, the KNN methods gave more satisfactory accuracy, the initial, cross-validated, and predictive classification rates were 97.1%, 97.1%, and 93.3%, respectively. The C, N, and O stable isotope analysis of spine samples may be used to verify the geographic origin of sea urchins. • The δ13C, δ15N, and δ18O values in the gonad and spine of sea urchin were analyzed. • The δ13C and δ15N values in gonads were different among geographic origins. • The δ15N and δ18O values in spines were different among geographic origins. • Stable isotopes in gonads gave low recognition in the discrimination models. • Stable isotopes in spines gave satisfactory results in the discrimination models. [ABSTRACT FROM AUTHOR]

Abstract: Fouling organisms on scallop cultivation nets and shells are costly to remove and can reduce scallop growth. In the present study, we investigated the biological control efficiency of using the sea urchin Hemicentrotus pulcherrimus as a means of preventing fouling in suspended scallop cultivation of Chlamys farreri and Patinopecten yessoensis in Sanggou Bay, Northern China. Tests were carried out from June to September 2009, during the period of the heaviest fouling. The scallops were co-cultured in scallop lantern nets for 3months. At the end of the experiment, all sea urchins were alive and the survival rates of scallops were very high. Scallop shell length and soft tissue growth were not significantly affected by sea urchins, but a greater growth in scallop soft tissue was associated with the presence of the sea urchin. Sea urchin had a minimal effect on the shell fouling of C. farreri, but noticeably reduced the weight of fouling on scallop nets and efficiently reduced fouling on the shell of P. yessoensis. Results suggest that the sea urchin was an effective biological control organism, especially for the shell fouling of P. yessoensis. This experiment indicated that biological control, using sea urchin, of fouling in suspended scallop cultivation has the potential to become an efficient and environmentally-sound method for addressing the problem of fouling in scallop cultivation. [Copyright &y& Elsevier]

Sea urchin, Strongylocentrotus intermedius, transplanted from Japan in 1989, has been widely cultured along the coasts of Liaoning and Shandong Provinces and has become the dominant and most economically important maricultured species in North China. However, a lesion syndrome symptom of S. intermedius broke out frequently these years, showing lethargy in activities, blackish peristomial membrane and body well lesions, and brought about high mortality eventually. Six representative prominent bacterial strains were isolated from diseased sea urchin from September 2009 to January 2010. By means of API 20 NE and 16S rRNA gene sequences analysis, isolates were identified as Shewanella aquimarina, Pseudoalteromonas tetraodonis, Vibrio shilonii, V. harveyi, V. fortis and V. splendidus. Bacterial challenge tests showed that their representative isolates were virulent to S. intermedius with LD50 values ranging from 9.2 × 104 to 3.4 × 106 CFU/g body weight, among which S. aquimarina , V. fortis and P. tetraodonis were highly virulent, and the other three isolates showed moderate virulence. The results indicated that a variety of bacteria including Shewanella, Pseudoalteromonas and Vibrio were involved in the mortality of S. intermedius, and the six isolates were opportunistic pathogens of sea urchins. All isolates reported herein were sensitive to ampicillin, enrofloxacin, ofloxacin, doxycycline and florfenicol. [ABSTRACT FROM AUTHOR]

Abstract: Assessment of the effectiveness of protected areas requires information on population characteristics of the target species. This study used a mark-and-recapture approach to examine the population structure, individual growth, and mortality of the commercially harvested short-spined sea urchin Anthocidaris crassispina in a small (18ha) no-take marine reserve and two nearby non-protected sites. Sea urchins were tagged with fluorochrome and recaptured 1 year later. The size-at-age relationship was modelled using the Tanaka function, and mortality estimated using an exponential decay function coupled with the Tanaka growth parameters. The urchin population in the reserve consisted of a higher proportion of older individuals than populations in the two non-protected areas, however, large sea urchins (>50mm) were absent in the reserve. Sea urchins occurring at high densities (>15ind.m−2) in the reserve grew much slower than those outside the reserve, suggesting a density-dependant effect on growth. Growth ring analysis from the rotulae supported the mark-and-recapture results with the maximum number of rings being higher in the reserve than in non-protected sites. Urchins with the same number of growth rings inside the reserve were smaller than those outside the reserve. Within the reserve, urchins with the same number of growth rings were smaller at locations with higher urchin density. Annual mortality rate was lower in the reserve population than in the non-protected populations. These results illustrate the effectiveness of this small reserve in protecting A. crassispina from fishing. However, further study is required to examine whether a high density of small/old individuals is better than a medium density of large individuals in order to maximize the potential spillover of larvae by such small urchin refugia to the surrounding overfished areas. [Copyright &y& Elsevier]

Abstract: In this study, sea urchins Anthocidaris crassispina, Diadema setosum and Salmacis sphaeroides inhabiting the coastal area of Hong Kong were collected and their gonadal biochemical compositions determined and compared for the first time. The proximate nutritional composition of all species exhibited an order of lipid>protein>carbohydrate. Neutral lipid was the major lipid constituent, accounting for over 80% of the total lipid. The major fatty acids in neutral lipid fraction of the three urchins were C14:0, C16:0, C16:1 (n-7), C18:1 (n-7) and C20:5 (n-3), whereas those in the polar lipid fraction were C16:0, C16:4 (n-4), C20:4 (n-6) and C20:5 (n-3). The dominant carotenoid was echinenone, which accounted for 81.7%, 56.7% and 68.5% of the total carotenoids in A. crassispina, D. setosum and S. sphaeroides, respectively. [Copyright &y& Elsevier]

Sea urchins serve as an essential niche for benthic ecosystems and are valuable seafood for humans. However, little is known about the microplastics (MPs) accumulation in sea urchins. Here, we investigated the abundances and characteristics of MPs in specific tissues of wild sea urchins for 12 sites across 2, 900 km of coastlines in northern China. Sea urchins from all sites were detected to have MPs, with a total detection rate of 89.52%. The MPs abundance in sea urchins from all sites ranged from 2.20 ± 1.50 to 10.04 ± 8.46 items/individual or 0.16 ± 0.09 to 2.25 ± 1.68 items/g wet weight. The samples from Dalian were found to have the highest value by individual, and samples from Lianyungang had the highest value by gram. Furthermore, MPs were found in different tissues of sea urchins, i.e., gut, coelomic fluid and gonads. The highest abundance of MPs was found in the gut of sea urchins, followed by coelomic fluid and gonads. The size of MPs ranged from 27 to 4742 μm, and the mean size found in gut was bigger than coelomic fluid and gonads. More interestingly, the MPs abundance increased with the decrease of anus size, shell diameter and gonad index (the wet weight ratio of gonad to total soft tissues). The MPs were dominated by fiber in shape, blue-green in colour and cellophane in composition. The high MPs abundance in sea urchins indicates the potential risks to human as they are consumed in many parts of the world, particularly in Asia and Europe., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)