• Korean Journal of Ichthyology
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• v.10 no.2
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• pp.176-183
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• 1998

Spawning ecology and feeding habits of Maurolicus muelleri in the Korean waters were studied. M. muelleri spawned continuously throughout the year showing a peak in August. Major spawning ground of this species was the southeastern sea of Korea. The fecundity observed from the ovaries of M. muelleri showed a range of 5,072 to 32,117, and the average number of eggs per one spawning time was approximately 250. M. muelleri was a zooplanktivore which fed mainly on copepods. Its diets also included various crustaceans such as amphipods, euphausiids, shrimps and mysids.

• Korean Journal of Ichthyology
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• v.7 no.1
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• pp.64-70
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• 1995

Vertical distribution of eggs and larvae of Maurolicus muelleri were studied in the south-eastern waters of Korea during 1985 and 1986. Samples were collected vertically at three different layers, 0~30 m, 30~50m and 50~100m. The densities of egg and larva were high in August. Eggs and zooplankton were abundant around the thermocline in the temperature range of $10{\sim}15^{\circ}C$ at the layers of 50 m depth in 1985, and 30~100m depth in 1986. Eggs in the cleavage stage were abundant at the layer of 50~100m depth, while those of processing embryonic body formation were tended to concentrate at the layer of 30~50m depth. The vertical distribution of each developmental stage differed according to sampling time. They were distributed uniformly at water column from 30 m to 100m depth in the midnight, but concentrated at the layer from 30 m to 50 m from dawn to sunset. Before and after midnight, eggs in the cleavage stage were most abundant. It was assumed that M. muelleri spawned at the layer of 50~100m depth around the midnight, and the eggs ascended to the layer of 30~50m depth with development.

• Korean Journal of Ichthyology
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• v.11 no.1
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• pp.62-71
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• 1999

The seasonal distribution of Maurolicus muelleri eggs and larvae were determined using samples collected from the Korea Strait and the southern part of the East Sea in May and November, 1992, August, 1993, and January, 1994. The eggs were most abundant in summer and the larvae in spring, while, their abundance was low in winter. The eggs were mainly found from in all season around sea of the front area of latitude $35{\sim}36^{\circ}N$ and the West Channel of the Korea Strait found the middle or bottom water lower than $15^{\circ}C$. The seasonal distribution of the eggs in the western Korea Strait varied according to the structure of the bottom cold water of the Korea Strait. The M. muelleri larvae in different stage were most abundant in the front area of latitude $35{\sim}36^{\circ}N$. The spawning and hatching area of the M. muelleri was considered to be the front area located in the shelf break, and some eggs can be transported into the Korea Strait by westward cold bottom current in summer. The Korea Strait would be the southern margin of the distribution of Maurolicus muelleri eggs and larvae of the East Sea.

• Korean Journal of Ichthyology
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• v.3 no.1
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• pp.11-23
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• 1991

To study the distribution of inhthyoplankton in the adjacent water of Wolsong, samples were collected using Bongo net from the surface water in November of 1989, and February, May and July of 1990. Fish eggs were divided into Engrualis japonicus, Callionymidae, Maurolicus muelleri, Konosirus punctatus, and others. The dominant species of fish eggs were Maurolicus muelleri and Callionymidae accounting for 60.1% and 13.7% of the total egg abundance, respectively. Total of 21 taxa of fish larvae occurred. The predominant species was Engraulis japonicas accounting for 61.2% of the total lavae, and bollowed by Callionymidae(11.9%). Other major species were Maurolicus muelleri, Gobiidae sp., Ammodytes personatus, Sebastes inermis, S. Pachycephalus, Scartella cristata, and Sebastiscus marmoratus. These 9 taxa constituted 96.5% of the total larvae collected. In this area, where upwelling occasionally occurs the distribution of fish eggs and larvae appeared to be affected by the transport of the surface water during the upwelling period.

• Ocean and Polar Research
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• v.24 no.4
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• pp.443-448
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• 2002

A study on the ichthyoplankton assemblage was conducted around Dokdo in the East Sea in September 1999 and May 2000. Sixteen species of fish larvae including eggs were collected during the surveys. Anchovy (Engraulis japonicus) eggs and larvae were comprised of 2.0% and 94.5% of total samples in number, respectively. Muller's pearlside (Maurolicus muelleri) eggs and larvae were comprised of 95.0% and 3.2%, respectively. The other species mostly composed of warm water species were less than 2% of total samples in number. The number of species and abundance of the fish lawae and eggs were higher in September than in May. Although there were limited data on the ichthyoplankton around Dokdo in summer and winter, this study area seems to be used for the spawning or nursery ground of fishes.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.378-386
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• 2007

To study the composition of the developmental stages of Maurolicus japonicus eggs distributed in the western Korea Strait, we investigated the water temperature, salinity, eggs and larvae in December 2002. The Korea Strait Bottom Cold Water (KSBCW) lower than $10^{\circ}C$ was found in off the Ulsan and Busan where M. japonicus eggs were the most abundant. The composition of the developmental stages of M. japonicus eggs at each station were composed of 37.7~89.5% in the first stage, 8.5~37.8% in the middle stage and 0.0~24.7% in the last stage respectively. In the southern area where the KSBCW appeared, the first stage eggs occupied 73.3~89.5%. The high percentage of the first stage eggs indicated that the eggs should be transported by the cold water lower than $10^{\circ}C$ from the Ulleung Basin in the East Sea. In the northern area where the KSBCW was not found, the first, middle and last stage eggs were composed of 37.5%, 37.8% and 24.7% respectively. The ratios of middle and last stage eggs were much higher than those in the southern area with the KSBCW, which implies that the eggs are recruited into the northern area from the southern area with the KSBCW by the Tsushima Warm Current. The pre-larvae found only in the middle and northern part of the study area would be hatched during the transport of eggs from the southern area with the KSBCW by the Tsushima Warm Current.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.4
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• pp.404-409
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• 1999

The in situ target strengths of, maurolicus muelleri were measured by the split beam echo sounder system at the frequency of 38kHz.Target strengths were measured during the night time in order to obtain the pure separated echoes from the scattered individual. And also it was to establish reasonable threshold due to taking the signals like as the planktons and etc.Since Maurolicus muelleri is a typical micronektonic fish, they mainly consisted of deep scattering layers(DSLs), and had a vertical migration perrodically during daytime and at night.We found that the Maurolicus muelleri occupied about 99% of total catch. Total length ranged from 4.5 to 5.7cm with a mean of 5.2cm and a standard deviation of 0.22cm.The target strengths of Maurolicus muelleir ranged from -60.4 to - 52.7dB and -59.2 to - 52.5 dB in the water layer of 10~30m and 30~50m depth, perspectively. Mean target strength was -57.1dB/fish and -28.5dB/kg. The target strength had the relation with the total length of the fish as, TS=20logL-71.4.

• Korean Journal of Ichthyology
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• v.11 no.1
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• pp.72-85
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• 1999

A study on the larval fish assemblage around the front area was conducted in the Korea Strait in August, 1993. The front was found in the shelf break located in $35{\sim}36^{\circ}N$. A total of 125 species were found in the study area. Of these Engraulis japonicus was the most dominant species comprising 84.3% of the total fish larvae collected and followed by Maurolicus muelleri accounting for 7.7%. Gobiidae, Callionymidae and Pomacentridae showed higher frequency of occurrence. These five species can be divided into three groups. First group was comprised in the larval fish species such as E. japonicus and Callionymidae which were found in the whole study area. The second group was comprised of Gobiidae and Pomacentridae which were found in the warm area located in the southern part of the front area. The other species was M. muelleri found in the cold area located in the northern part of the front area including the front area. The assemblage, geological distribution and body length composition of the fish larvae in the Korea Strait would be mainly determined by the spawning ecology of the fishes, and the geological distribution and structure of the front which is formed in the ocean boundary between the Tsushima Current and the East Sea Cold Water.

• Korean Journal of Ichthyology
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• v.34 no.3
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• pp.186-200
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• 2022

In order to understand the species composition and distribution characteristics of larval assemblages in the East Sea, Korea, larvae were collected at 13 stations every other month from February to December 2018. Fish larvae were identified through DNA barcoding along with morphological methods, and as the result, a total of 104 taxonomic groups appeared during the survey. Among these, Engraulis japonicus, which accounted for 76.2% of the total population, was the most dominant species, followed by Maurolicus japonicus, which accounted for 15.0%. In addition, Ammodytes personatus, Champsodon snyderi, Scomber japonicus and Echelus uropterus appeared more frequently than other taxa. The above six species accounted for 93.2% of the total catch. The number of taxa and the amount of larvae collected in the survey area were higher during the high water temperature periods (June to October) than during the low water temperature periods (February, April and December). Analysis of similarity (ANOSIM) showed a statistically significant difference in monthly larval assemblages. The results of the canonical correspondence analysis (CCA) show that the distributions of larval community were mainly affected by sea surface temperature during low water temperature periods, and various environmental factors such as salinity, dry weight of zooplankton, and the concentrations of nutrients during high water temperature periods.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.332-342
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• 2007

Species composition and quantitative and body length composition of the ichthyoplankton were investigated by samples collected from the coastal waters of uljin in January, April, July and October, 2002. During the study, the collected fish eggs were identified as belonging to 7 taxa. The most of dominant species Engraulis japonicus, were accounted for 38.34% of the total fish eggs, followed by Sillago sihama (25.84%). The collected larvae and juveniles were identified into 25 taxa, 18 families, 7 orders. The domninant species Engraulis japonicus accounted for 90.46% of the total larvae and juveniles, followed by Sebastes schlegeli 2.04%. These 2 taxa constituted 92.50% of the total collected larvae and juveniles. The diversity index of species per months of the collected juveniles the coastal water of Uljin, 2002 was 0.0878~2.3855 and the evenness index was 0.0451~0.9300. in case of dominance index was 0.3000~0.9914 against the evenness index. The analyzed species diversity index by the each stations was 0.3035~0.7440 and the dominance index was 0.8919~0.9669 against the species diversity index. The similarity of community structure per season was very high because of the relative difference (0.010), which was the least in Summer and Fall. In addition, the community structure was very similar in state 1 and state 4 out of each stations because the relative difference was the least, 0.139.