• Journal of Applied Biological Chemistry
• /
• v.58 no.4
• /
• pp.363-368
• /
• 2015

The pharmacokinetics of florfenicol were studied in healthy and vibriosis-infected large yellow croaker (Pseudosciaena crocea) following administration of a single oral dose of $20mg{\cdot}kg^{-1}$ at $25{\pm}2^{\circ}C$. After oral administration, florfenicol levels in tissues (liver, kidney, muscle, serum, and skin) were analyzed using high-performance liquid chromatography. A two-compartment open model was used to describe the pharmacokinetics of florfenicol following oral administration. Compared to the healthy group, the absorption rate of vibriosis-infected fish significantly decreased, peak-time ($T_{max}$) delayed, maximum concentration ($C_{max}$) declined, total body clearance decreased, the elimination half-life ($T_{1/2{\beta}}$) was extended, and the area under the curve increased. These results indicate that a $20mg{\cdot}kg^{-1}$ oral dose of florfenicol administered once daily continuously for 4 or 5 days can be used for the treatment of Vibrio alginolyticus infection in large yellow croaker (Pseudosciaena crocea).

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.49 no.2
• /
• pp.224-233
• /
• 2016

The objective of this study was to develop an artificial neural network (ANN) model for the acoustic identification of commercially important fish species in Korea. A broadband echo acquisition and processing system operating over the frequency range of 85-225 kHz was used to collect and process species-specific, time-frequency feature images from six fish species: black rockfish Sebastes schlegeli, black scraper Thamnaconus modesutus [K], chub mackerel Scomber japonicus, goldeye rockfish Sebastes thompsoni, konoshiro gizzard shad Konosirus punctatus and large yellow croaker Larimichthys crocea. An ANN classifier was developed to identify fish species acoustically on the basis of only 100 dimension time-frequency features extracted by the principal components analysis (PCA). The overall mean identification rate for the six fish species was 88.5%, with individual identification rates of 76.6% for black rockfish, 82.8% for black scraper, 93.8% for chub mackerel, 90.6% for goldeye rockfish, 96.9% for konoshiro gizzard shad and 90.6% for large yellow croaker, respectively. These results demonstrate that individual live fish in well-controlled environments can be identified accurately by the proposed ANN model.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.6
• /
• pp.939-944
• /
• 1994

The change of major organic acid contents were examined in mackerel, pacific yellow croaker and brown sole on heating conditions. The organic acid contents of mackerel were the higher that the others. The content of lactic acid was the highest in all samples commonly and that of succinic acid was second level and these organic acids were over 95% of total organic acid. The content of ${\alpha}-ketoglutaric$ acid was higher acid content was greater with higher heating temperature. Decreasing of organic acid content was higher at steamed and first heating than warmed and rewarmed.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.58 no.3
• /
• pp.205-213
• /
• 2022

The experimental fish transplanted from China in 2015 was used after seedling production and cultivated. Breeding management for experiment was carried out from October 2020 to February 2021. Also, it succeeded in inducing artificial maturation three to four months earlier than wild broodstock and secured good quality fertilized eggs. The average size of fertilized eggs was 1.22 mm, at 20℃ Blastodisc (15 minutes post-fertilization), 2 cell (50 minutes), 4 cell (1 hours), 8 cell (2 hours), 16 cell (2 hours and 30 minutes), 32 cell (2 hours and 50 minutes), morula (3 hours), blastula (8 hours), gastrula (15 hours), skull formation (20 hours), organ formation (30 hours) and hatching yolk larvae stage (35 hours). The total length of the just hatched larvae were 2.50 ± 2 mm, and then gain growth of 42.5 mm by 60 days, reaching 45 ± 5 mm.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.3 no.3
• /
• pp.154-160
• /
• 1970

The present paper deals with the growth of yellow croaker by scale age reading. This study is based on material from 596 specimens caught by the Danish seine in the Yellow Sea during the period from June 1967 to April 1968. Ring marks of the scale were formed from April to July, corresponding to the spawning season of the fish reported by Bae (1960). Growth rate of each radius of the ring was approximately 0.73. The relationship between the total length and radius of scales, and the relationship between the body weight and total length are represented by the following equations respectively: L=61.350R+50.184 $$W=4.298L^{3.227}\times10^{-3}$$ Maximum total length calculated by the diagram of Walford's growth transformation, $$L_{n+1}=0.6866L_n+10.8730$$, was 346.9mm. Growth curve of the fish can be expressed by the following von Bertalanffy's equation : $$L_t=346.9(1-e^{-0.376(t+0.609)})$$

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.37 no.6
• /
• pp.478-484
• /
• 2004

On 11 June 1991, eggs from the brood stock of small yellow croaker (Larimichthys polyactis) were artificially fertilized using the standard dry method and were hatched. Each of the fertilized eggs (1.1-1.2 mm in diameter) had an oil globule and was transparent and buoyant. The fertilized eggs hatched in a range of water temperatures $(17.5-20.3^{\circ}C)$ 44 hrs after fertilization. The total lengths of the newly hatched larvae were 3.1-3.3 mm, and these hatchlings had 31 myotomes (10+21). Melanophores and yellow-brown chromatophores were concentrated on the head, at the ventral part of the yolk, and in the middle of the tail. Four days after hatching, the larvae completely absorbed the yolk and became flexions of 5.1-5.5 mm in total length. Fifteen days after hatching, one spine (the anterior tip of the maxillary) appeared in the upper jaw and three spines developed at the upper parts of the eyes and on the posterior part of the head. At this stage, the larvae were approximately 8.3 mm long. Thirty-nine days after hatching, juveniles (1.9-3.4 mm in total length) had a pointed tail fin. By 66 days after hatching, the juvenile fish (about 4.0-6.5 mm in total length) were similar to adult fish in body shape. The larvae of L. polyactis could be distinguished from those of L. croacea by two distinct characteristics: the large number of vertebrae (28-29), and a relatively small bony ridge on the occipital region of the head.

• Journal of Fisheries and Marine Sciences Education
• /
• v.26 no.1
• /
• pp.98-107
• /
• 2014

As part of a series of studies about improving yellow croaker drift gill net fishing gear and the development of a labor-saving fishing system, we installed a labor-saving-type, five-step-drum net hauler, and a triple-V-type net hauler in 108 Daeheung-ho, a fishing boat which operates drift gill nets for yellow croakers mainly in the sea near Chu-ja Island. Net damage with the labor-saving-type, five-step-drum net hauler is lower than for the triple-V-type net hauler. In addition, there was a reduction in the standard operational crew of two people. The lead time for hauling the labor-saving net was approximately 10% and 19.2% less than for hauling the triple-V-type net hauler and for hauling by hand, respectively. It was found that there were fewer slip in fishing gear and less damage to the wing of the drum as well as less damage to the fish when the labor-saving-type, five-step-drum net hauler was used than when the triple-V-type net hauler was used. In the survey, the lead time for hauling the net was approximately 21.6% and 45.2% more effective than hauling with the triple-V-type net hauler and hauling by hand, respectively. The crew was reduced by approximately 18.2% and 25% than when hauling with the triple-V-type net hauler and hauling by hand, respectively. In addition, cessation of operation and damage to the fish were reduced when compared to the triple-V-type net hauler and hauling by hand.

• Journal of Life Science
• /
• v.31 no.3
• /
• pp.314-320
• /
• 2021

In the present study, we investigated the effect of photoperiod and water temperature on the gonadosomatic index (GSI), histological stage of the testes, and plasma levels of sex steroid (testosterone, T; 11-ketotestosterone, 11-KT) hormones in cultured male small yellow croakers (Larimichthys polyactis). In a photoperiod experiment, small yellow croakers were reared under a natural photoperiod (NP, 10L:14D-11L:13D), long photoperiod (LP, 14L:10D), and short photoperiod (SP, 10L:14D) at 17℃ for 90 days. The GSI was significantly higher in the LP group than in the other groups at 30 and 60 days. The plasma 11-KT levels were significantly higher in the LP group than in the other groups at 30 days. In a water temperature experiment, small yellow croakers were reared under natural water temperature (NT, 19.1-15.0℃), or at 17℃, 21℃, or 25℃ under a LP (14L:10D) for 60 days. The GSI was significantly lower for the 25℃ group than for the other groups at 30 and 60 days. The plasma 11-KT levels were significantly lower for the 25℃ group than for the other groups at 60 days. Therefore, the sexual maturation of cultured male yellow croakers was promoted by LP and inhibited at water temperatures above 25℃. These findings suggest that the sexual maturation of cultured male small yellow croakers is controlled by both the photoperiod and the water temperature.

• Korean Journal of Food Science and Technology
• /
• v.34 no.5
• /
• pp.762-769
• /
• 2002

As a preliminary test for defining intact yellow croaker pigment, the pigment was analyzed by column chromatography and UV-vis spectrophotometry. All maximum absorbance wavelengths commonly showed three maximum absorbance ranges, similar to those of carotenoid, suggesting that the tested pigment may be carotenoid. We detected total six peak RT values in the chromatogram through PDA-HPLC under gradient mode (behavior A at 10% for initial 2 min and changed to behavior B for 60 min). Most pigments were detected at the peak with 3.27 RT value. Because seven peaks were detected under gradient mode and three under isocratic mode [methanol : methylene chloride (90 : 10, v/v)], gradient mode was determined to be more appropriate for quantitative analysis. By the comparison test of RT values among yellow pigment in croakers and reference pigments, such as zeaxanthine, ${\beta}-cryptoxanthine$, ${\beta}-carotene$, and astaxanthin, only ${\beta}-cryptoxanthine$ was detected in the white croaker, whereas such pigment of yellow croaker having RT value of 31.02 was not detected. Therefore, RT value was found to be applicable for detecting adulterated croaker.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.55 no.5
• /
• pp.645-654
• /
• 2022

This study was conducted to prepare superheated steam roasted (SSR) small yellow croaker Larimichthys polyactis sweet potato salad (SPS) and tomato mousse (TM), as senior-friendly seafoods (SFS) and to examine their quality characteristics. The hardness values of SSR, SPS and TM were 110.5×1.0³, 22.4×1.0³ and 14.5×1.0³ N/m², respectively. The nutritional properties of SSR, SPS and TM were 22.4, 6.7 and 10.2 g/100 g, respectively, for protein, 97.01, 3.40 and 17.00 ㎍/100 g, respectively, for vitamin A, 10.26, 2.79 ㎍/100 g and not detected (ND), respectively, for vitamin D, 60.68 mg/100 g, ND and 4.17 mg/100 g, respectively, for vitamin C, 0.18, 0.10 and 0.33 mg/100 g, respectively, for riboflavin 24.28, 10.91 and 13.77 mg/100 g, respectively, for niacin, 76.3, 53.0 and 48.5 mg/100 g, respectively, for calcium, 258.2, 231.3 and 145.2 mg/100 g, respectively, for potassium, and ND, 0.70 mg/100 g and ND, respectively, for dietary fiber. Escherichia coli was not detected in any of the products. These results suggested that the products should be classified as step 1 for SSR, step 2 for SPS and step 3 for TM based on the SFS standard of the Korean industrial standards. Moreover, the nutritional and physical properties of the foods were improved.