• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.628-634
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• 2016

We investigated the characteristics and rate of development of allotriploid embryos derived from a cross between female olive flounder Paralichthys olivaceus and male starry flounder Platichthys stellatus. The allotriploidy was induced by cold shocking fertilized eggs three minutes post-fertilization at 3°C for 45 minutes. The average cellular DNA content of the allotriploid embryos was 2.06±0.03 pg/cell, which is equal to the sum of the cellular DNA content of a diploid olive flounder (1.42 pg/cell) and a haploid starry flounder (0.66 pg/haploid cell). The first cleavage, midblastula, gastrula and Kupffer's vesicle appearance stages of the allotriploid eggs began at 1.5, 8, 13 and 26 hours after cold shocking at 18°C, respectively. The developmental rate of allotriploid eggs was equivalent to that of diploid and triploid olive flounder eggs at 10, 14 and 18°C. However, the hatching times of allotriploid eggs, 7 h at 10°C, 5 h at 14°C and 4 h at 18°C, were earlier than those of diploid and triploid olive flounder.

• Journal of fish pathology
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• v.22 no.3
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• pp.211-218
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• 2009

In this study, we have compared the genome of marine birnavirus (MABV) detected from starry flounder Platichthys stellatus and olive flounder Paralichthys olivaceus. A molecular analysis based on the nucleotide sequence (433 bases) of VP2-NS-VP3 region revealed that MABV (08-KU) from starry flounder showed 98% similarity with MABV Y6 isolated from Yellowtail Seriola quinqueradita in Japan (Accession no: AY283781) and with other aquabirnaviruses identify more than 76%. Comparison with MABV strains (06-KP, 08-KC) from olive flounder and MABV Y6 strain showed 97-98% sequence identities. Phylogenetic analysis was performed in order to examine the relationship among previously determined aquatic birnaviruses isolates showed that MABV and IPNV strains were classified into seven clusters. Three isolates from starry flounder and olive flounder in this study, belong to the genogroup VII including MABV Y6 strain and other aquabirnaviruses isolated from marine fish and molluscan shellfish in Japan. This report is the first description of a MABV from starry flounder in Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.6
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• pp.679-685
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• 2012

A study was carried out to observe the effects of feed types on the growth, feed preference, and enteric feed transition rate of juvenile starry flounder, Platichthys stellatus for 45 days. Fifty fish (avg. 135 g) were stocked each in replication, and fed a commercial extruded pellet diet (EP, 45% protein) and a moist pellet diet (MP, 65% raw mackerel+35% feed powder in wet basis), respectively. The MP presented the higher performance than that of the EP on the feed efficiency ($68.3{\pm}0.9%$ for EP and $92.3{\pm}4.3%$ for MP) and the specific growth rate ($1.07{\pm}0.07$ for the EP and $1.20{\pm}0.05%$ for the MP). In contrast, the EP showed the higher feed preference in terms of the daily feed intake ($1.57{\pm}0.08%$ for the EP and $1.30{\pm}0.01$ for the MP) and the ad libitum feeding rate after a fast of 72 hours (1.73% for the EP and 1.35% for the MP). The feed transition rate through intestinal canals decreased exponentially in both the EP and the MP, showing the faster transition rate with the EP. In the result, starry flounder appeared to have the better feed preference to the EP, but have the higher feed efficiency and growth performance to the MP.

• Fisheries and Aquatic Sciences
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• v.22 no.1
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• pp.3.1-3.8
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• 2019

The purpose of this study is to investigate the changes in growth, hematological parameters, and plasma components of juvenile starry flounder, Platichthys stellatus, following exposure to varying arsenic concentrations present at different water temperatures. P. stellatus (total length, $15.9{\pm}0.4cm$; body weight, $62.2{\pm}4.2g$) were exposed for 4 weeks to waterborne arsenic (sodium arsenite, As) at 0, 150, 300, and $600{\mu}g/L$ at temperatures of $12^{\circ}C$ and $18^{\circ}C$. Toxic effects of As exposure on P. stellatus were higher at the higher temperature and the growth and hematological parameters measured decreased with increasing arsenic concentration, while the concentration of plasma components measured increased. This indicates that waterborne As exposure and water temperature can cause toxic effects on growth, hematological parameters, and plasma components in Platichthys stellatus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.2
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• pp.113-118
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• 2008

Diel rhythm of oxygen consumption (OC) of the starry flounder Platichthys stellatus was measured at different water temperatures in a closed recirculating seawater system with a respiratory chamber. The fish consumed 70.5, 79.7, and 90.6 mg $O_2/kg/hr$ at 15, 20, and $25^{\circ}C$, respectively, showing a linear increase in OC with water temperature. The OC of fish showed a clear diel rhythm, with lower values during the day and higher values at night, in accordance with the light (09:00-21:00) and dark (21:00-09:00) phases of the diel cycle (12L:12D) in water at 15 and $20^{\circ}C$. However, the OC of the fish showed an unclear diel rhythm with the light and dark phases of the diel cycle at $25^{\circ}C$. The respective OC at 15, 20 and $25^{\circ}C$ was 63.8, 72.4, and 88.4 mg $O_2/kg/hr$ during the light phases and 77.2, 87.1, and 92.8 mg $O_2/kg/hr$ during the dark phase. The starry flounder is thought to be a nocturnal fish with a higher OC at night, while it rests during the day. Its OC was the most stable in the light, when it did not feed. Consequently, the night-time OC is the active OC and the day-time OC is the resting OC in the starry flounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.793-800
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• 2013

This study was conducted to determine the physiological and histological characteristics of starry flounder Platichthys stellatus juveniles to undergo a short/long starvation period and subsequent re-feeding with 2 weeks interval for 65 days. All findings from this study indicate the possibility of a very rapid recovery possibility of starry flounder after short starvation period for 2 or 4 weeks. The mean body weight after 2 and 4 weeks starvation were not significantly different after 65 days. However, the body weight of 6 and 8 weeks starved fishes showed significantly low value than 2 weeks starved fishes. All biomarkers, liver somatic index, RNA/DNA ratio and blood chemistry, in this study showed fast recovery possibility after re-feeding of starry flounder. During the starvation and recovery process, they showed distinct increasing and decreasing tendency. From 21-28 days after re-feeding, most biomarkers reached to their maximum value and thereafter decreased again in 2, 4 and 6 weeks starvation and re-feeding groups. It could be interpreted as a compensatory growth and strategical action against starvation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.431-434
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• 2014

Cytogenetic analysis was conducted to obtain basic information for chromosome manipulation of starry flounder Platichthys stellatus. Nuclear surface area and volume of erythrocyte were $7.60{\pm}0.93{\mu}m^2$ and $12.80{\pm}1.75{\mu}m^3$, respectively. The haploid DNA content of the species was 0.66 pg/haploid cell which correspond to 93% of olive flounder Paralichthys olivaceus. A karyotype analysis was also carried out with the species using conventional staining and Ag-NOR banding techniques. It was consisted of 48 acrocentric chromosomes and inter-sex or intra-individual polymorphism was not detected in all specimens analyzed. The NOR regions, appearing a terminal position of the short arm of the smallest acrocentric pairs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.4
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• pp.373-379
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• 2023

The dietary inclusion of black soldier fly larvae meal Hermetia illucens (BSL) for starry flounder Platichthys stellatus was examined in a four-month trial at a Pohang fish farm. Two diets were prepared: a fish meal-based commercial diet (CD) and an experimental diet containing 7% BSL in the CD (BCD). Fish (average weight, 125.2 g) were reared in a square concrete tank (7×7 m) in triplicates. Feed efficiency was significantly higher in fish fed BCD compared to that of the fish fed CD. The DHA/EPA ratio in dorsal muscle was not significantly affected by the fatty acid composition of the experimental diets. Based on the growth performance, the feed cost for producing 1 kg of starry flounder was 1,797 won for CD and 1,814 won for BCD. With government subsidies the feed cost for producing 1 kg of starry flounder was 1,481 won for CD and 1,309 won for BCD. The results indicate that BSL can be included at 7% without adverse effects on growth performance, fillet composition, or feed cost. However, further research is needed to determine the optimum percentage of BSL as a replacement of FM in starry flounder diets.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.4
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• pp.1098-1106
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• 2016

To study the influence of light intensity on blind-side hypermelanosis of starry flounder, Platichthys stellatus, we compared growth, glucose, cortisol, ratio of malpigmented blind-side area, ambicolored fish ratio and expression of mch mRNA for 60 days in 0 lux(darkness) and 20 lux(low light density). The test was done in duplicate at 50 fish/tank with the selected ordinary juvenile flounder. The rearing was performed in FRP aquarium tanks ($H100cm{\times}L100cm{\times}W100cm$). Growth was higher in the 0 lux. The ratio of malpigmented blind-side area and ambicolored fish ratio were significantly higher at the 0 lux than at the 20 lux. The result suggests that 20 lux could inhibit the hypermelanosis. The expression level of MCH 1, 2 mRNA was significantly lower in 0 lux, indicating that MCH 1, 2 and light intensity are related to blind-side hypermelanosis of starry flounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.1
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• pp.87-91
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• 2019

Effects of feeding frequency on the growth performance of juvenile starry flounder Platichthys stellatus were investigated. One thousand fifty fishes were distributed into 15 of 500-L flow-through tanks. Triplicate groups of were fed experimental diet with five feeding frequency (one meal every two days, one meal a day, two meals a day, three meals a day and four meals a day) for 9 weeks. Weight gain and specific growth rate (SGR) of fish fed two meals a day were higher than those of fish fed one meal 2 days and one meal a day, but not different from those of fish fed three meals a day and four meals a day. Feed consumption of fish fed two meals a day was not different from that of fish fed three meals a day and four meals a day. Feed efficiency (FE) and protein efficiency ratio (PER) of fish fed two meals a day were higher than those of fish fed all other diets, except for three meals a day. These results suggest that the optimal feeding frequency is two meals a day for the optimum growth performance of juvenile starry flounder under the experimental conditions.