• 한국전자현미경학회:학술대회논문집
• /
• 한국현미경학회 2001년도 제32차 추계학술대회
• /
• pp.46-48
• /
• 2001

• 한국패류학회지
• /
• 제18권1호
• /
• pp.9-14
• /
• 2002

In order to estimate the genetic variability and differentiation in common squid, eleven isozymic loci, coded for nine enzymes detected by starch gel electrophoresis, were scored from nine spawning cohorts in four localities. The expected average heterozygosity ranged from 0.00019 (between II-S$_2$ and Na-W) to 0.00814 (Between Bu-S and Na-W) in nine different spawning cohorts in four localities. A dendrogram, based on genetic distance mentioned, illustrated that nine different spawning cohorts were divided into three groups, similar to the result estimated by their ecological characterizations. From these results, we estimate that the common squid distributed throughout Korean waters will maintain this gene exchange. It is postulated that either the summer or the autumn spawning cohort has developed a local population that is isolated by hydrographic factors.

• Fisheries and Aquatic Sciences
• /
• 제10권4호
• /
• pp.179-185
• /
• 2007

Understanding dietary habits is one of the most important factors in studying food webs and other ecological processes. Here we designed universal primers to amplify portions of the 18S and 28S rDNA sequences to examine gut contents using PCR techniques. The gut contents of sailfin sandfish (Arctoscopus japonicus) and pacific squid (Todarodes pacificus) were examined. In total, 11 families of prey were identified with 18S and 28S rDNA using the universal primers. The DNA sequence data indicated that the primer sets successfully amplified a wide spectrum of species and represented gut contents in a relatively convenient way. We found that information in the NCBI database was not yet sufficient to discriminate the species we isolated. In addition, technology for the separation of heterogeneous PCR products and better resolution and quantification protocols would help increase data accuracy.

• 한국수산과학회지
• /
• 제31권1호
• /
• pp.26-30
• /
• 1998

본 연구는 1991년 2월부터 1992년 7월까지 한국 해역에 분포하는 오징어의 위내용물을 분석한 것이다. 위내용물의 종류를 살펴보면, 해조류, 갑각류, 두족류, 어류 외 동정 불가능한 것도 나타났다. 먹이생물중 어류를 가장 많이 먹었으며, 그 다음으로 두족류, 갑각류, 해조류 순으로 섭이하는 것으로 나타났다. 위의 만복도 조성에서 공위가 $58.00\%$이었고, 만복된 위는 $6.37\%$이었다. 여름과 가을 계군은 어류를 가장 많이 섭이한 반면, 겨울계군은 두족류를 매우 우점적으로 섭이하였다. 해조류와 갑각류는 세 계군 모두 매우 적은 양이 섭이되었다. 오징어의 주요 먹이생물은 어류이었고, 계군에 따른 위내용물의 차이는 없었다.

• 한국어업기술학회:학술대회논문집
• /
• 한국어업기술학회 2002년도 춘계 수산관련학회 공둥학술발표회
• /
• pp.617-617
• /
• 2002

• 한국전자현미경학회:학술대회논문집
• /
• 한국현미경학회 2001년도 제32차 춘계학술대회
• /
• pp.33-36
• /
• 2001

• 한국수산과학회지
• /
• 제44권3호
• /
• pp.267-275
• /
• 2011

The common squid Todarodes pacificus is an ecologically and commercially important species in Korea and Japan. However, the distribution pattern of its eggs and larvae in Korean waters has not yet been clarified. To determine the horizontal and temporal distribution of common squid larvae in the northern East China Sea, samples collected using paired, 60 cm diameter Bongo nets from the three surveys conducted in August 2003, May 2004 and November 2005 were examined. In addition, the vertical distribution was examined from the samples collected using a $1\;m^2$ MOCNESS in April 1999 (20 m interval down to 100 m). A total of 218 larvae ranging in mantle length (ML) from 1.2 to 17.0 mm were counted at 27 stations. Larval abundance was highest in May 2004. The larvae mainly occurred in the southeastern area of Jeju Island, where the water temperature and salinity at 50 m deep ranged from $15-23^{\circ}C$ and 34-34.6 psu, respectively. Most larvae were collected in the frontal zone, where the Tsushima Warm Current and inshore waters meet. The results from the MOCNESS samples showed that the larvae occurred mostly in 20-80 m depth ranges (about 90%), although collections were only conducted above 100 m. No significant differences in larval mantle lengths (ANOVA, P>0.05) were found among each depth interval. Given the occurrence sites of the larvae <2.0 mm ML, the spawning ground of this species appears to be within the northern East China Sea, mainly to the southeast and northeast of Jeju Island, in early spring.

• 한국수산과학회지
• /
• 제51권6호
• /
• pp.656-666
• /
• 2018

To evaluate the optimal time for extracting lipids from the viscera of the common squid Todarodes pacificus the proximate and fatty acid compositions of the liver and gonads of commercial squid were analyzed according to sex for 6 months (Jul. to Sept. and Nov. to Jan.). The body and liver weights of the squid were larger in females than in males, and were larger from Nov. to Jan. than from Jul. to Sept. in both sexes. The average lipid contents in the livers of female and male squid were also higher from Nov. to Jan (22.9% and 24.9%, respectively) than from Jul. to Sept. (11.7% and 17.5%, respectively). The average lipid contents of the ovaries and testes were 5.16% and 1.76%, respectively, and changed little over the 6 months. The percentage of n-3 polyunsaturated fatty acids (eicosapentaenoic acid + docosahexaenoic acid) was higher in the gonads (44.8-49.1%) than in the liver (36.3-37.6%). These results suggest that Nov. to Jan. is the best time to extract lipids from the liver, whereas there was no difference in the efficacy of lipid extraction from the gonads between the two seasons.

• 한국수산과학회지
• /
• 제54권5호
• /
• pp.724-732
• /
• 2021

This study used response surface methodology to investigate the optimal conditions to reduce the bitterness of alcalase-treated anchovy hydrolysate (AAH) by the aminopeptidase active fraction (AAF) derived from the common squid Todarodes pacificus hepatopancreas. The central composite design selected AAF/AAH ratio (X₁, %) and hydrolysis time (X₂, h) as independent variables, and the degree of hydrolysis (Y₁) and bitterness (Y₂) as dependent variables. The uncoded values of the multiple response optimization for independent variables were 3.4% for the AAF/AAH ratio and 9.2 h for the hydrolysis time. The predicted values of the yield and bitterness score of alcalase-AAF continuously treated anchovy hydrolysate (AAAH) under the optimized conditions were 68.9% and 4.6 points, respectively. Their measured values of 69.5% for yield and 4.6±0.5 points for bitterness were similar to the predicted values. The food components of AAAH were 91.4% (moisture), 7.5% (protein), 0.1% (lipid) and 0.6% (ash). The findings indicate the potential value for use as an anchovy seasoning base. The results also confirm that the bitterness of AAH was remarkably improved by AAF and implicates AAF derived from squid hepatopancreas as a good enzyme to catalyze reduced bitterness.

• 한국수산과학회지
• /
• 제55권2호
• /
• pp.183-188
• /
• 2022

It is a difficult task to estimate parameters in even a simple stock assessment model such as a surplus production model, using only data about temporal catch-per-unit-effort (CPUE) (or survey index) and fishery yields. Such difficulty is exacerbated when time-varying parameters are treated as random effects (aka state variables). To overcome the difficulty, previous studies incorporated somewhat subjective assumptions (e.g., B₁=K) or informative priors of parameters. A key is how to build an objective joint prior of parameters, reducing subjectivity. Given the limited data on temporal CPUEs and fishery yields from 1999-2020 for common squid Todarodes pacificus, we built a joint prior of only two parameters, intrinsic growth rate (r) and carrying capacity (K), based on the resilience level of the population (Froese et al., 2017), and used a Bayesian state-space production assessment model. We used template model builder (TMB), a R package for implementing the assessment model, and estimating all parameters in the model. The predicted annual biomass was in the range of 0.76×10⁶ to 4.06×10⁶ MT, the estimated MSY was 0.13×10⁶ MT, the estimated r was 0.24, and the estimated K was 2.10×10⁶ MT.