Topic
Black scraper
About: Black scraper is a research topic. Over the lifetime, 18 publications have been published within this topic receiving 139 citations.
Papers
TL;DR: In this article, the genetic diversity and relationships among four wild populations and two hatchery stocks of Korean black scraper were assessed based on 16 microsatellite (MS) markers.
Abstract: The Korean black scraper, Thamnaconus modestus, is one of the most economically important maricultural fish species in Korea. However, the annual catch of this fish has been continuously declining over the past several decades. In this study, the genetic diversity and relationships among four wild populations and two hatchery stocks of Korean black scraper were assessed based on 16 microsatellite (MS) markers. A total of 319 different alleles were detected over all loci with an average of 19.94 alleles per locus. The hatchery stocks [mean number of alleles (N
A) = 12, allelic richness (A
R) = 12, expected heterozygosity (He) = 0.834] showed a slight reduction (P > 0.05) in genetic variability in comparison with wild populations (mean N
A = 13.86, A
R = 12.35, He = 0.844), suggesting a sufficient level of genetic variation in the hatchery populations. Similarly low levels of inbreeding and significant Hardy–Weinberg equilibrium deviations were detected in both wild and hatchery populations. The genetic subdivision among all six populations was low but significant (overall F
ST = 0.008, P < 0.01). Pairwise F
ST, a phylogenetic tree, and multidimensional scaling analysis suggested the existence of three geographically structured populations based on different sea basin origins, although the isolation-by-distance model was rejected. This result was corroborated by an analysis of molecular variance. This genetic differentiation may result from the co-effects of various factors, such as historical dispersal, local environment and ocean currents. These three geographical groups can be considered as independent management units. Our results show that MS markers may be suitable not only for the genetic monitoring of hatchery stocks but also for revealing the population structure of Korean black scraper populations. These results will provide critical information for breeding programs, the management of cultured stocks and the conservation of this species.
22 citations
1 Jan 2013
TL;DR: Assessment of the genetic diversity and relationships among four wild populations and two hatchery stocks of Korean black scraper suggested the existence of three geographically structured populations based on different sea basin origins, although the isolation-by-distance model was rejected.
Abstract: The Korean black scraper, Thamnaconus modestus, is one of the most economically important maricultural fish species in Korea. However, the annual catch of this fish has been continuously declining over the past several decades. In this study, the genetic diversity and relationships among four wild populations and two hatchery stocks of Korean black scraper were assessed based on 16 microsatellite (MS) markers. A total of 319 different alleles were detected over all loci with an average of 19.94 alleles per locus. The hatchery stocks [mean number of alleles (N A) = 12, allelic richness (A R) = 12, expected heterozygosity (He) = 0.834] showed a slight reduction (P > 0.05) in genetic variability in comparison with wild populations (mean N A = 13.86, A R = 12.35, He = 0.844), suggesting a sufficient level of genetic variation in the hatchery populations. Similarly low levels of inbreeding and significant Hardy–Weinberg equilibrium deviations were detected in both wild and hatchery populations. The genetic subdivision among all six populations was low but significant (overall F ST = 0.008, P < 0.01). Pairwise F ST, a phylogenetic tree, and multidimensional scaling analysis suggested the existence of three geographically structured populations based on different sea basin origins, although the isolation-by-distance model was rejected. This result was corroborated by an analysis of molecular variance. This genetic differentiation may result from the co-effects of various factors, such as historical dispersal, local environment and ocean currents. These three geographical groups can be considered as independent management units. Our results show that MS markers may be suitable not only for the genetic monitoring of hatchery stocks but also for revealing the population structure of Korean black scraper populations. These results will provide critical information for breeding programs, the management of cultured stocks and the conservation of this species.
18 citations
TL;DR: It is suggested that the feeding pressure of filefish on jellyfish polyps may have an impact on medusa biomass.
Abstract: Although jellyfish are important predators of fish larvae, many fish species also feed on jellyfish. Therefore, the predator–prey role of jellyfish and fish may switch during the course of their life histories. Here, we investigated such interactions by examining (1) the avoidance behaviour of threadsail filefish Stephanolepis cirrhifer to moon jellyfish Aurelia sp. and (2) the feeding behaviour of filefish on moon jellyfish medusae and polyps. The efficiency of filefish as jellyfish predators was examined by comparing their behaviour with that of black scraper Thamnaconus modestus and red sea bream Pagrus major. Filefish and black scraper were able to avoid medusae and obtain tolerance against nematocysts at a smaller body size compared to red sea bream. Filefish initiated feeding on medusae when they became juveniles of 21.8 mm SL. Feeding trials of yearling filefish on polyps at different temperatures (range 10–30°C) indicated that the highest feeding rate was 3.1 individuals s−1 at 26.8°C. We suggest that the feeding pressure of filefish on jellyfish polyps may have an impact on medusa biomass.
14 citations
TL;DR: The procedure developed in the present study is applicable to the commercial-scale seed production of black scraper and demonstrated that sand is the optimum spawning substrate when compared to a hard polyvinyl chloride sheet, a piece of shading net, or artificial spawning grass.
Abstract: To develop an efficient and stable method for enhancing spawning of black scrapers in captivity, we examined the following three factors: (1) different kinds of spawning substrate, (2) the area of the spawning substrate, (3) the grain size of the spawning substrate. The results demonstrated that sand is the optimum spawning substrate when compared to a hard polyvinyl chloride sheet, a piece of shading net, or artificial spawning grass. No difference was observed in the spawning frequency between a small sand bed of area 400 cm2 and sand spread over the bottom of the tank to an area of 7085 cm2, since the egg masses were spawned on the sand in a small area approximately 15 cm in diameter. In addition to the spawned eggs, the small movable sand bed is useful for subsequent harvest. No differences were observed in either the spawning frequency or the hatching rate when using sand beds with different grain sizes. In large-scale egg collection trials, an average of 33 egg masses from which an average of 403,000 larval fish were obtained. We can therefore conclude that the procedure developed in the present study is applicable to the commercial-scale seed production of black scraper.
14 citations
TL;DR: The results indicate lower genetic variability in the hatchery population than in the wild population and minor, but significant, genetic differentiation between the two populations.
Abstract: In this study, we developed 20 polymorphic microsatellite markers for the Korean black scraper, Thamnaconus modestus (Gunther, 1877), Monacanthidae, and used them to compare allelic variation between wild and hatchery populations in Korea. All loci were readily amplified and demonstrated allelic variability, with the number of alleles ranging from 5–35 in the wild population and 5–22 in the farmed population. The average observed and expected heterozygosities were estimated, respectively, as 0.74 and 0.80 in the hatchery samples and 0.78 and 0.81 in the wild ones. These results indicate lower genetic variability in the hatchery population than in the wild population and minor, but significant, genetic differentiation between the two populations (FST = 0.005, P < 0.01). Additionally, cross-amplification was tested in another monacanthid species, Stephanolepis cirrhifer; many loci were found that yielded useful information. The high degree of polymorphism exhibited by the 20 microsatellites will be useful in future aquaculture and population genetic studies for developing conservation and management plans.
12 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2018 | 2 |
| 2017 | 1 |
| 2016 | 2 |
| 2014 | 4 |
| 2013 | 4 |
| 2012 | 1 |