• 한국수산과학회지
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• 제56권3호
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• pp.324-330
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• 2023

We investigated the relative growth and squamation of larvae and juveniles of cultured Larimichthys polyactis. Analysis of the relative growth of larvae and juveniles showed that their preanal length, head length, eye diameter, body depth, and snout length increased with growth. There was no significant chage in the relative growth. The ratio of preanus length to standard length (SL) increased rapidly until SL was approximately 12 mm, and then increased gradually. Cycloid scales first appeared on the lateral line, progressed to the abdominal cavity at 15.13 mm SL, and expanded to the occipital region, base of pectoral fin, and ventral region of the eye at 17.82 mm SL. At 18.03 mm SL, scales formed on the cheek, and those at the base of pectoral fin and in the abdominal cavity were connected to each other. At 19.06 mm SL, major part of the head was covered by scales, except near the lower jaw. Cycloid scales on the lateral line changed to ctenoid scales at the range of 31.71-32.24 mm SL, and those on the nape changed at the range of 69.02-70.84 mm SL. Our results may help to establish conservation and management strategy for Larimichthys polyactis aquaculture.

• 한국수산과학회지
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• 제45권3호
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• pp.271-282
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• 2012

Early osteological development of the skull, vertebral column, and fins, and squamation in the spotted sea bass, Lateolabrax maculates, were studied under extensive larval rearing conditions. The first ossification during cephalic skeleton development began with the premaxillary, dentary, and parasphenoid at 6.4 mm Total length (Notochord length 6.1 mm) and was completed by 25.2 mm TL (Standard length 20.3 mm). Ossification of the cartilaginous caudal complex started simultaneously in the urostyle and two preural centra at 12.2 mm TL (10.4 mm) and it was completely ossified by 32.0 mm TL (26.4 mm). The principal caudal fin rays, with a count of 9/8, began to ossify at 11.6 mm TL (10.2 mm) and the procurrent caudal fin rays, with counts of 4 (upper) and 3 (lower), started to ossify by 12.6 mm TL (10.9 mm). Ossification of these parts was completed by 21.4 mm TL (17.5 mm). Ossification of the vertebral column was first observed in the first to fourth centra at 8.3 mm TL (7.5 mm) and was fully completed by 21.7-35.0 mm TL (17.8-29.3 mm). The pectoral girdle started to ossify by 5.6 mm TL (5.4 mm) and was completed by 26.8 mm TL (21.8 mm). Eight pectoral fin rays were ossified at 11.6 mm TL (10.2 mm) and 16-18 rays were fully ossified by 13.8 mm TL (12.0 mm). Also, the dorsal, anal, and pelvic fin rays started to ossify at 12.2 mm TL (10.4 mm) and were completed by 12.8 mm TL (11.2 mm), 23.8 mm TL (19.4 mm), and 13.8 mm TL (12.0 mm), respectively. Ossification of the anal and dorsal pterygiophores initially occurred by 12.6 mm TL (10.9 mm) and 14.3 mm TL (12.2 mm), and was completed by 21.4 mm TL (17.5 mm) and 19.3 mm TL (15.9 mm), respectively. Squamation started at three centers of differentiation: the middle region of the trunk, the anterior of the caudal peduncle, and on the caudal peduncle at 23.8 mm TL (19.4 mm). The body was covered with scales, except the snout, at 57.2-60.2 mm TL (SL 47.1-49.2 mm).

• 한국어류학회지
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• 제24권2호
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• pp.125-130
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• 2012

민어, Miichthys miiuy (Basilewsky)에서의 지느러미 분화, 두부 계측 및 비늘 도포 양상의 초기 형태학적 발달을 조사하였다. 부화 후 12일(전장 4.2 mm 미만)에, 어체 주위로 fin-fold의 존재가 관찰되었다. 등지느러미, 뒷지느러미 및 가슴지느러미의 기조 형성은 부화 후 12일에 거의 완전히 이루어진 반면, 지느러미 분절은 부화 후 26일과 29일 사이에 이루어졌다. 꼬리지느러미 중간 기조의 신장은 부화 후 32일에 시작되었으며 부화 후 37일에 현저하였다. 부화 후 68일에 꼬리지느러미가 뾰족해지기 시작하였다(전장 70.7 mm). 비늘의 발달은 전장이 9.1mm(부화 후 28일)일 때 미병의 측선부위로부터 시작되어 결국 아가미덮개 전체를 도포하였다(전장 22.1 mm, 부화 후 44일). 두부 계측치들은 전장이 12 mm 이상(부화 후 30일)에서 거의 안정화되었다.

• 한국동물위생학회지
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• 제32권3호
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• pp.189-200
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• 2009

The purpose of this study was to evaluate the effect of a subsequent infection of PCV2 on piglets with PEDV. In clinical signs, the signs observed in dual-infected with PEDV and PCV2 piglets and alone infected with PEDV piglets ranged from diarrhoea to vomiting and dehydration. Dual-infected piglets developed signs of anorexia, vomiting and watery diarrhoea within 12 hpi. Nevertheless alone -infected piglets caused pasty diarrhea at first. In mortality, dual infections showed 25%, but alone -infections showed 8.3%, respectively. In gross findings, piglets dual-infected with PEDV and PCV2 appeared the severe findings of congestion, distension of lumen, milder curdes of undigested milk in stomach than those of single-infected piglets. In histopathological findings, piglets of dual-infection group appeared the more severe findings of villous atrophy and fusion, congesion, exfoliation, vacuolation, squamation, loss of cilia and proliferation of crypt. Significant (P<0.05) decrease in VH:CD ratio in dually infected piglets compared to piglets from alone-PEDV infections. In immunohistochemical findings, strong hybridization signals in dual-infected piglets observed moderate to severe villous atrophy or vacuolation with positive cells arranged continuously over the villi. In the lumen, exfoliated enterocytes were strongly positive in dual-infected piglets. A number of PEDV-positive cells in dual-infected pigs were significantly higher than that in alone PEDV-infected piglets.

• 한국수의병리학회지
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• 제7권1호
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• pp.43-54
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• 2003

The purpose of this study was to investigate protective effects against transmissible gastroenteritis virus (TGEV) infection in piglets by administration of the TGEV antiserum orally at 2hrs, 24hrs and 36hrs after birth. Five piglets administered with the TGEV antiserum were experimentally challenged with TGEV at four-day-old. Control group was four piglets challenged with TGEV only. Clinical signs and gross, histopathological and immunohistochemical findings were examined. In clinical signs, piglets of the control group appeared the typical signs such as severe watery diarrhea, depression and anorexia but piglets of the TGEV antiserum adminstered group recovered progressively. In clinical signs, piglets of the control group appeared the typical signs such as severe watery diarrhea, depression and anorexia but piglets of the TGEV antiserum adminstered group recovered progressively. In mortality, control group showed 75%, but TGEV antiserum adminstered group showed 20.0 %, respectively. In gross findings, piglets of the control group appeared the typical findings of congestion, distension of lumen, contaning curdes of undigested milk in stomach. But gross findings of piglets of the TGEV antiserum adminstered group appeared milder than them of control group. In histopathological findings, piglets of the control group appeared the typical findings of villous atrophy and fusion, congesion, exfoliation, vacuolation, squamation, loss of cilia and proliferation of crypt. But histopathological findings of piglets of the TGEV antiserum adminstered group appeared milder than them of control group. In immunohistochemical findings, piglets of the TGEV antiserum adminstered group showed more intensive in reaction for IgA and IgG than them of control group. The recation for IgA was stronger than that of IgG. It was concluded that oral administration of TGEV antiserum to piglets was effective to prevent TGEV infection and reduce their mortality.

• 한국수의병리학회지
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• 제6권1호
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• pp.27-39
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• 2002

The purpose of this study was to investigate to protective effects against porcine epidemic diarrhea virus (PEDV) infection in piglets by administration of the PEDV antiserum orally at 2 hrs, 24hrs and 36hrs after birth. six piglets administered the antiserum were experimentally infected with PEDV at five-day-old. Control group were four piglets infected with PEDV only. Clinical signs and gross, histopathological lesion and immunohistochemical findings were examined. The results obtained were as follows; 1. In clinical signs, piglets of the control group appeared the typical signs of severe watery diarrhea, depression and anorexia but piglets of the PEDV antiserum treated group recovered progressively. In mortality, control group showed 75%, but PEDV antiserum treated group showed 16.7%, respectively. 2. In gross findings, piglets of the control group appeared the typical findings of congestion, distension of lumen, containing curdes of undigested milk in stomach. But piglets of the PEDV antiserum treated group appeared milder than those of control group. 3. In histopathological findings, piglets of the control group appeared the typical findings of villous atrophy and fusion, congesion, exfoliation, vacuolation, squamation, loss of cilia and proliferation of crypt. But piglets of the PEDV antiserum treated group appeared milder than those of control group. 4. In immunohistochemical findings, piglets of the PEDV antiserum treated group showed more intensive in reaction for IgG and IgG than those of control group. The recation for IgA was stronger than that of IgG. It was concluded that oral administration of PEDV antiserum to piglets was effective in preventing PEDV infection and reduced their mortality.

• 대한수의학회지
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• 제61권4호
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• pp.30.1-30.11
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• 2021

From April 2014 to September 2015, 153 piglets from 52 farms in Jeju were diagnosed with porcine epidemic diarrhea (PED). The major PED cases were focused on suckling piglets (144 piglets, 94.1%), particularly in 1-7-day-old piglets. Histopathologically, severe villous atrophy was observed in the small intestine, especially in the jejunum and ileum. The mean villous height to crypt depth ratios of the jejunum and ileum were 1.4:1 and 1.5:1, respectively. The major histopathologic findings of the small intestine were cytoplasmic vacuolation, cuboidalization, squamation, and exfoliation of the mucosal enterocytes in the villi. The cytoplasmic vacuolations in the enterocytes were the most prevalent lesions in the small intestine and were more severe in the ileum than in the jejunum. According to immunohistochemistry methods, the PED virus (PEDV) antigens were presented in the cytoplasms of the enterocytes, and were distributed more prevalently in the ileum than in the jejunum. PEDV antigens were also detected in the colon of 26 piglets (19.5%). Sequence comparison and phylogenetic analysis indicated that 12 PEDV had more than a 98.9% homology with each other. These PEDV strains were highly homologous with the genogroup 2 North American group.

• 한국어류학회지
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• 제32권3호
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• pp.166-181
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• 2020

조종천에 서식하는 한국고유종 쉬리 Coreoleuciscus splendidus (Gobioninae)의 초기생활사와 자연산란장 연구를 2020년 5월에 수행하였다. 수정란의 크기는 2.05~2.23 mm (평균, 2.13 mm)로 유구는 없었다. 수온 20±1℃에서 수정 후 약 98시간이 경과하여 부화하기 시작하였다. 부화자어의 전장은 5.03~5.68 mm (평균, 5.31 mm)로 입과 항문은 열리지 않았다. 부화 4일 후 전장은 6.95~7.89 mm (평균, 7.51 mm)로 자어의 머리와 체측면에서 막대 모양의 cupulae가 관찰되었다. 부화 후 7일의 전장은 8.39~9.29 mm (평균 8.78 mm)로 난황이 완전히 흡수되어 후기자어기로 이행하였고 cupulae는 명확하게 관찰되었다. 부화 후 29일에는 전장은 14.16~17.04 mm (평균, 14.99 mm)로 모든 지느러미의 기조수가 정수에 도달하여 치어기로 이행하였다. 부화 후 38일의 전장은 18.21~23.74 mm (평균, 19.42 mm)로 비늘은 미병부부터 발달이 시작되었다. 부화 후 73일에는 전장 26.82~33.33 mm (평균, 30.28 mm)로 외부 형태적 특징은 성어와 유사하였다. 쉬리의 자연산란장은 조약돌(64~16 mm)과 자갈(16~2 mm)이 바닥에 깔려있었으며, 수심 6~18 cm, 바닥부분의 유속은 0.43~0.73 m/sec인 지역이었다. 수정란은 난괴(egg mass) 또는 개별적으로 분리된 형태로 조약돌과 자갈 아래의 작은 간극에 위치하였다.