동자개(Pseudobagrus fulvidraco)의 생식소 퇴화에 미치는 수온과 광주기의 영향

임상구(Sang-Gu LIM),김영수(Young-Soo KIM),한창희(Chang-Hee HAN) 한국수산해양교육학회 2012 水産海洋敎育硏究 Vol.24 No.6

To investigate the role of temperatures and photoperiods as environmental cues regulating reproductive rhythm in Pseudobagrus fulvidraco, rearing experiments were conducted using sveral rearing regimes conbined with photoperiods and water temperatures during gonadal degeneration periods. Gonadosomatic index (GSI) in control was 8.16±1.50%, while in other experiment GSI levels in female were lower than that in the control. In case of experimental precinct of 9 light (L) and 15 L, GSI levels were decreased. But GSI level with 20℃ was no diffrence after 40 and 60 days. GSI level in male of control was 0.35±0.05%. GSI under 9 L and 25℃ was similar to that in control, whereas its level in other experiments was lower than that in control. Testosterone (T) of female was 3.68±0.22 ng/mL at experimental precinct. In case of 9 L and 15 L, concentration of T were lower than experimental precinct in all of water temperature. Estradiol-17β (E₂) and 7α, 20β-dihydroxy-4-pregnen-3-one (17α20βOHP) levels of female were 0.42±0.02 and 0.83±0.01 ng/mL at experimental precinct. E₂ levels of 9 and 15 L were higher than experimental precinct and 17α20βOHP levels of 9 and 15 L were higher than experimental precinct. In case of T and 11-ketotestosterone levels were 0.69±0.11 and 0.62±0.03 ng/mL in male. During the period of gonadal degeneration, gonadal maturation did not occur in any of the experimental regimes. However, comparatively high levels of E₂ observed at low temperature regimes (20℃) regardless of photoperiods.

점농어 Lateolabrax maculatus의 성 성숙에 미치는 광주기의 영향

임상구(Sang-Gu LIM),김영수(Young-Soo KIM),백재민(Jae-Min BAEK),김종현(Jong-Hyun KIM),한형균(Hyoung-Kyun HAN),조용철(Yong-Chul CHO),강용진(Yong-Jin KANG) 한국수산해양교육학회 2014 水産海洋敎育硏究 Vol.26 No.5

To investigate effect of on sexual maturation in spotted seabass, Lateolabrax maculatus the sexual maturation, photoperiods were established to natural photoperiod, 9L:15D, 11L:13D, 13L:11D and 15L:9D. After rearing for 90 days from August 11 to November 10, gonadosomatic index (GSI) and hormones were analyzed. In the female, GSI was 1.07±0.09% in the natural photoperiod, 1.93±0.06% in 9L:15D, while the GSI of male was 0.75±0.05% in the natural photoperiod, 1.89±0.12% in 9L:15D and 0.22±0.05% in 15L:9D and the lowest in 15L:9D, respectively. The blood estradiol (E2) of female was 226.0±13.6 pg/ml in the natural photoperiod, and the highest value of 296.3±15.0 pg/ml in 9L:15D. The male 17α20βOHP was similar to the female with 196.3±17.0 pg/ml in the natural photo period and 133.0±15.5 pg/ml in 9L:15D. The testosterone (T) of male was 259.3±33.1 pg/ml in the natural photoperiod, but the hightest value of 370.5±27.5 pg/ml in 9L:15D. These results provide basic information from sexual maturation of spotted seabass.

Physiological effects of dietary vitamin E on kelp grouper, Epinephelus bruneus under low water temperature stress

Sang-Gu LIM(임상구),Tae-Ho LEE(길현우),Hyun-Woo GIL(이태호),In-Seok PARK(박인석) 한국수산해양교육학회 2017 水産海洋敎育硏究 Vol.29 No.3

The physiological response of the longtooth grouper, Epinephelus bruneus to low water temperature (LWT) stress while on three different concentrations of dietary vitamin E (1 mg/diet g, 5 mg/diet g, and 10 mg /diet g) were investigated. Plasma cortisol, glucose, and aspartate aminotransferase (AST) levels were higher in the control and sham control compared with the vitamin E supplemented groups. The most addition with vitamin E in the diet (10 mg/diet g) showed the lowest levels of cortisol, glucose, and AST. However, plasma alanine aminotransferase (ALT) showed no significant differences across all experimental conditions (P>0.05). Also the more disposing vitamin E into feeding the better resistance against stress on the LWT was shown through cortisol, glucose, ALT, and AST.

Histological Observation of the Barbel in Common Carp, Cyprinus carpio and Bagrid Catfish, Pseudobagrus fulvidraco

Sang-Gu LIM(임상구),Hyoung-Kyun HAN(한형균),Hye-Jung PARK(박혜정),In-Seok PARK(박인석) 한국수산해양교육학회 2014 水産海洋敎育硏究 Vol.26 No.2

잉어, Cyprinus carpio와 동자개, Pseudobagrus fulvidraco의 상악ㆍ하악 수염을 조직학적으로 조사하였다. 동자개의 수염은 연골성 증축(axial rod of cartilage), 신경섬유다발(bundle of nerve fiber), 표피(epidermis), 평활근 층(smooth muscle layer) 및 미뢰(taste bud)로 구성되었으며, 잉어의 수염은 표피, 신경섬유다발, 혈관(blood vessel) 및 미뢰로 구성되었다. 수염 길이에서 잉어는 상악 바깥쪽 수염(second maxillary barbel)이 상악 안쪽 수염(first maxillary barbel) 보다 길게 나타났으며, 동자개는 하악 안쪽(inner mandibular barbel), 상악 위쪽(upper maxillary barbel), 하악 바깥쪽(outer mandibular barbel), 상악 아래쪽(lower maxillary barbel) 순으로 길게 나타났다(P<0.05). 미뢰의 수를 고려하였을 때, 동자개와 잉어간의 미각에 대한 유의적 차이가 없었다(P>0.05). 아울러, 두 어종의 모든 수염에서 수염 상부의 미뢰 수가 하부의 미뢰 수 보다 높게 나타났다(P<0.05). 본 연구 결과, 동자개의 수염은 딱딱하며 굴절성인 수염(flexible and stiff type)이었으며 잉어의 수염은 연하고 유연한 수염(tender and yielding type)으로 파악되었다.

Skeleton and Scale Characteristics of Smallscale Blackfish, Girella leonina and Largescale Blackfish, Girella punctata

Sang-Gu LIM(임상구),Jin-Ah SONG(송진아),Tae-Ho LEE(이태호),Hyun-Woo GIL(길현우),In-Seok PARK(박인석) 한국수산해양교육학회 2017 水産海洋敎育硏究 Vol.29 No.4

Two Girellidae species, smallscale blackfish, Girella leonina and largescale blackfish, G. punctata were compared using meristic traits, scale characteristics, and X-ray approaches. Meristic counts revealed three significant differences out of seven meristic characteristics (P < 0.05). Girella leonina had more numbers of dorsal soft rays, caudal fin rays, and pectoral fin rays while G. punctata had more numbers of gill rakers (P < 0.05). X-ray photographs indicated that G. punctata (45.1 ± 2.34°) had 8.4% more curved vertebral column than G. leonina (38.4 ± 1.82°). However, G. leonina (24.5 ± 2.51°) had more curved caudal fin than G. punctata (18.2 ± 2.16°) in crescent shaped tail. Regarding the results of scale comparison between G. leonina and G. punctata, scales of five sites displayed different sizes. The overall scale size of G. punctata (2.5 ± 0.56 ㎠) was 1.8 times larger than G. leonina (1.4 ± 0.35 ㎠). However, samples with the same ctenoid scale of ctenii showed different number of pored lateral line scales and primary apical groove (P < 0.05). The morphological differences between G. leonina and G. punctata were primarily the caudal part of truss dimension, x-ray observations, and scales. Our results confirmed that the two species could be adequately distinguished by their external body shape. The results of our study could be used to identify them in the family of Girellidae through taxonomical parameters.

해산송사리, Oryzias dancena의 산란행동 분석

임상구 ( Sang Gu Lim ),한형균 ( Hyung Kyun Han ),김광석 ( Kwang Seog Kim ),김봉석 ( Bong Seok Kim ),백현민 ( Hyun Min Baek ),박인석 ( In Seok Park ),길현우 ( Hyun Woo Gil ) 한국어류학회 2012 韓國魚類學會誌 Vol.24 No.3

본 연구는 해산송사리, Oryzias dancena의 산란행위를 분석하여 인공산란 기술 개발에 그 목적이 있 다. 실험 사육수조에서 관찰한 결과, 실험 시작 후 모든 수컷이 각자 목표로 한 암컷을 쫓아감과 동시에, 상대적으로 큰 수컷이 작은 수컷의 생식공을 공격하여 축출하는 행동(biting, expelling)을 보였다. 이후, 수컷은 암컷과 나란히 유영하며 구애행동을 보였으며, 뒷지느러미와 등지느러미를 이용해 암컷의 어체를 감싸고 방란 및 방정 한 결과, 수정난은 암컷의 생식공 부근에 부착되어 있었다. 수컷이 covering 하는 동안 암컷이 재빨리 앞으로 유 영하는 행동을 많은 빈도로 관찰하였는바, 이는 암컷이 수컷의 구애행동을 거절하는 경우라고 사료된다. 총 빈 도 81%의 산란행동 요인 2가지를 분석한 결과(P/0.05), 요인 1 (biting, expelling)은 암컷을 차지하기 위한 수 컷의 방어 행동으로 총 빈도의 23.1%였으며(P/0.05), 요인 2 (chasing, parallel swimming, covering, reject)는 산란을 위한 행동으로 총 빈도의 59.7%를 차지하였다(P/0.05). 본 결과는 해산송사리 종 보존의 기본적 생물학 적 자료 제공과 아울러 인공산란 기법에 유용한 자료로 쓰일 것이다. The aim of this study is to observe the reproductive behavior of the marine medaka, Oryzias dancena, and determine the factors of reproductive behavior to provide useful information for improving their artificial reproduction techniques. The reproductive behavior of the marine medaka was observed in laboratory aquaria. Once the experiment began, all of the males chased the females. The males attempted to stimulate the urogenital openings of the females. While chasing a female, a large male would bite a relatively small male``s anus. Larger males expelled smaller males with biting, and the defeated males were barred from the female. After the other males were expelled, the remaining male approached and drew alongside the female. The male``s dorsal and anal fins covered the female``s body. Spawning began after complete covering took place. Spawning of males and females occurred simultaneously. The loadings for 2 factors were calculated. The calculation was restricted to 2 factors because these 2 factors explained about 81% of the total common variance (P/0.05) and the following factors possessed no practical significance. Two movements (biting, expelling) had high positive values for factor one. This factor related a male``s defensive behavior to courtship behavior and spawning, and explained 23.1% of the total common variance (P/0.05). The second factor had high positive values for chasing, rejection, covering, and parallel swimming. This factor related a male``s courtship behavior and female``s defensive behavior to spawning, and explained 59.7% of the total common variance (P/ 0.05). This research provided basic biological data for the conservation of this species and useful information for improving their artificial reproduction techniques.

Comparison of Morphological Characteristics between Smallscale Blackfish, Girella leonina and Largescale Blackfish, G. punctata

Sang-Gu LIM(임상구),Min-Hwoan JEONG(정민환),Tae-Ho LEE(이태호),Hyun-Woo GIL(길현우),In-Seok PARK(박인석) 한국수산해양교육학회 2016 水産海洋敎育硏究 Vol.28 No.6

In order to discriminate the morphologically analogous smallscale blackfish, Girella leonina and largescale blackfish, G. punctata, various methods were used by using biometric and geometric approaches. Morphometric analysis showed considerable 19 differences of total 44 morphometric dimensions: classical dimension 1 part; truss dimension 12 parts; and head part dimension 6 parts (P < 0.05). Some differences of morphological features primarily involved in caudal part of truss dimension. Our results of this study confirmed that two species adequately can distinguish with external body shape, and we hope that the results of our study could be used to identify in Girellidae family as taxonomical parameters.

동자개(Pseudobagrus fulvidraco)의 생식소 발달에 수온과 광주기가 미치는 영향에 관한 연구

임상구(Sang-Gu LIM),한창희(Chang-Hee HAN) 한국수산해양교육학회 2012 水産海洋敎育硏究 Vol.24 No.6

To investigate the role of water temperatures and photoperidos as environmental cues regulating reproductive rhythm in banded catfish Pseudobagrus fulvidraco, rearing experiments were conducted using sveral rearing regimes conbined with changes in photoperiods and water temperatures during growing and spawning periods. GSI of 23℃ was significantly higher than 18℃ in female, but 9 light of 18 and 23℃ were no difference in male. In case of estradiol, 18℃ and 15 L was higher than other experintal precinct after 20 days. But, end of the experiment, all of experimental precinct were no diffrence. Testosteron of female was no diffrence in 18℃-9 and 15 L after 20 days. Testosteron of male was no diffrence in 18℃-9 L. In case of 11-KT, control level was 0.39±0.03 ng/mL and 18℃-9 L was no significantly difference after 20 days. But, 15 L was higher than other experimental precinct.

붉은쏨뱅이 (Sebastiscus tertius) 피부계의 미세구조 및 조직화학적 특징

백재민,김철원,임상구,이제봉,이정식,Baek, Jae-Min,Kim, Chul-Won,Lim, Sang-Gu,Lee, Jae-Bong,Lee, Jung-Sick 한국현미경학회 2004 Applied microscopy Vol.34 No.2

Integumentary structures of the rockfish, Sebastiscus tertius were examined by means of the light and transmission electron microscopy. Stratified epidermal layer consists of supporting cells, unicellular glands, granular cells and mitochondria-rich cells. The epidermal layer could be classified into superficial, intermediate and basal layer by morphology and structure of the supporting cells. Mucous cells of unicellular gland were observed in the superficial and intermediate layer of the epidermis. The mucous materials were identified as acidic and carboxylated mucosubstance by histochemical methods. Club cell has well-developed central vacuole, rough endoplasmic reticula and Golgi complex in the cytoplasm. Granular cells were observed in the superficial layer and contained numerous granules of high electron density. Mitochondria-rich cells are characterized by well-developed microfilaments in cortex and numerous tubular mitochondria in medullar cytoplasm. Three types of pigment cells in the dermal layer could be distinguished with electron density of cytoplasmic inclusions. 붉은쏨뱅이의 피부 상피층은 다층상피층으로 지지세포, 선세포, 과립세포 그리고 mitochodria-rich cell들로 구성된다. 상피층은 지지세포의 형태와 구조에 따라 표면층, 중간층 및 기저층으로 구분할 수 있다. 점액세포들은 단세포선으로 상피의 표면층과 중간층에 분포하며, 산성의 비황화 뮤코다당류로 구성된 점액을 가진다. 곤봉상세포는 세포질에 잘 발달된 중심공포, 조면소포체 및 골지체를 가진다. 과립세포는 표면층에 존재하며, 전자밀도가 높은 과립을 가진다. mitochodria-rich cell의 주변부 세포질에는 미세섬유 다발이 발달되어 있으며, 수질부에는 다수의 관상 미토콘드리아를 가진다. 색소세포는 세포질에 존재하는 함유물의 전자밀도에 따라 세 종류로 구분할 수 있다.

사료 내 효소처리어분이 치어기 참다랑어 (Thunnus orientalis) 성장에 미치는 영향

지승철(Seung-Cheol JI),김봉석(Bongseok KIM),임상구(Sang-Gu LIM),김강웅(Kang-Woong KIM),신재형(Jaehyeong SHIN),이경준(Kyeong-Jun LEE) 한국수산해양교육학회 2017 水産海洋敎育硏究 Vol.29 No.5

This study was conducted to estimate dietary utilization of enzyme treated fish meal (EFM) on juvenile pacific bluefin tuna (PBT) Thunuus orientalis. In first experiment (EXP 1), the pacific bluefin tuna (initial body weight 2.36g) was randomly disposed two experimental tanks. The fish were fed EFM containing 31.9% of enzyme treated fish meal and sand lance (SL) for 15 days, respectively. Weight gain (WG) was showed lower in EFM than SL. But survival and protein efficiency ratio (PER) were higher in EFM than SL. Feed conversion ratio (FCR) of EFT lower than SL. In second experiment (EXP 2) was conducted to retest growth performance between EFM and SL. The high PER and survival were obtained in EFM than SL, and FCR of EFM was lower than that of SL. EFM are suitable dietary protein source in diet of juvenile PBT considering FCR, PER and survival in feeding trial.