• Applied Microscopy
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• 제50권
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• pp.13.1-13.7
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• 2020

We examined the morphology of fertilized egg and ultrastructures of fertilized egg envelopes of Ancistrus cirrhosus belong to Loricariidae using light and electron microscopes. The fertilized eggs formed a mass on the spawning place and were yellowish, spherical, non-transparent, demersal, adhesive, and a narrow perivitelline space. But, the adhesiveness of fertilized eggs was disappeared after spawning excluding contact parts. The micropyle with funnel shape was surrounded by 15-19 furrow lines of egg envelope in a spoke-like pattern. The outer surface of egg envelope has smooth side and inner surface of egg envelope was rough with grooves. Also, the total thickness of the fertilized egg envelope was about 32.58 ± 0.85 ㎛ (n = 20), and the fertilized egg envelope consisted of three layers, an outer adhesive electron-dense layer, a middle layer with low electron density and an inner electron-dense layer with grooves in counter structure from other most teleost. Collectively, these morphological characteristics and adhesive property of fertilized egg, and ultrastructures of micropyle, outer surface, and section of fertilized egg envelope are showed species specificity.

• Applied Microscopy
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• 제52권
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• pp.6.1-6.5
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• 2022

We examined the morphology of the fertilized egg and the fine structure of fertilized egg envelopes of Poropanchax normani belonging to the family Poeciliidae, also known as Norman's lampeye using light and electron microscopes. The fertilized eggs with narrow perivitelline space were found to be spherical and demersal, additionally containing small oil droplets in the vitelline membrane. Further, a bundle of adhesive filaments was observed to be present on one side of the fertilized egg. These filaments possessed remarkably high elasticity and were approximately 1-3mm in length. The size of the fertilized egg was determined to be about 1.49 ± 0.07mm (n=30). The outer surface appeared smooth, and adhesive filaments originating at different location of the surface of the envelope were found to be distributed around the egg envelope and were joined together to form a single long bundle in scanning electron microscopic observation. A peak-like structure formed of several straight wrinkles was observed around the micropyle. However, the complete structure of the micropyle could not be studied due to the depth at which it was located. Additionally, the total thickness of the egg envelope was ascertained to be approximately12.5-14.5㎛. The egg envelope consisted of two distinct layers, an outer electron dense layer and an inner lamellar layer, further consisting of 10 sublayers of varying thicknesses. Collectively, it was observed that the morphological characteristics of the fertilized egg, fine structures surrounding the micropyle, outer surface, adhesive structure consisting adhesive filaments, and sections of fertilized egg envelope displayed species specificity.

• Journal of Biosystems Engineering
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• 제20권4호
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• pp.368-375
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• 1995

A computer vision system was built to generate images of a stationary egg. This system includes a. CCD camera, a frame grabber, and an incandescent back lighting system An image processing algorithm was developed to accurately detect surface holes and surface cracks on eggs. With 20W of incandescent back light, the detection rate was shown to be the highest. The Sobel operator was found to be the best among various enhancing filters examined. The threshold value to distinguish between the crack and the translucent spots was found to be linear with the average gray level of a whole egg image. Those values of both gray level and area were used as criteria to detect holes in egg and those values of both area and roundness were used to detect cracks in egg. For a sample of 300 eggs, this system was able to correctly analyze an egg for the presence of a defect 97.5% of the time. On the average, it took 59.5 seconds to analyze an egg image and determine whether or not it was defected.

• Applied Microscopy
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• 제45권3호
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• pp.144-149
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• 2015

Nothobranchius guentheri and Nothobranchius patrizii have special life cycle to sustain the dry season. So, we investigated the fertilized eggs morphology, and compared ultrastructures of surface structures and the cross section of fertilized egg envelopes using light and electron microscopes to determine whether these fertilized eggs and egg envelopes show the species specificity or have special structure to sustain the dry season. These fertilized eggs were spherical, yellowish, demersal and adhesive, and had a one-sided large oil droplet. The whip-like structures, adhesive filament were distributed throughout egg envelope in both species. But, that of N. guentheri was covered with fibrous structures, and that of N. patrizii was smooth. The egg envelope consisted of two distinct layers: an outer, electron-dense layer containing adhesive filaments and an inner layer of 16 to 17 horizontal electron-dense lamellae alternating with 15 to 16 interlamellae of lower electron density in both species. The external shapes of fertilized egg and section of fertilized egg envelope were same, but ultrastructure of adhesive filaments on the outer surface was concluded to show species specificity. Our data indicate that the ultrastructural differences of adhesive filament and outer surface of fertilized egg envelope show species specificity although these species belong to same genus.

• Applied Microscopy
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• 제41권1호
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• pp.13-20
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• 2011

바다빙어목(Osmeriformes), 바다빙어과(Osmeridae)에 속하는 빙어(Hypomesus nipponensis)의 성숙란 난막구조를 광학현미경과 전자현미경을 이용하여 관찰하였다. 빙어의 성숙란은 두 개의 난막으로 둘러싸여 있었으며 바깥쪽 난막의 외층은 한 층의 여포세포가 분포하고 있었고 안쪽의 난막 바깥쪽은 호염기성을 나타내는 구조물들이 배열하고 있었다. 난막의 단면을 투과전자현미경으로 관찰한 결과 두 개의 난막 중 바깥쪽 막은 전자밀도가 균일한 한 층으로 되어 있었고 안쪽막은 전자밀도가 높은 6층이 전자밀도가 낮은 5층에 의해서 분리되어 층상구조를 하고 있었다. 주사전자현미경으로 관찰한 결과 바깥쪽 막은 홈들이 관찰되었고 안쪽막 표면은 무정형의 구조물들이 산재하고 있었다. 또한 동물극 쪽에 한 개의 난문이 관찰되었다. 이상과 같이 빙어의 성숙란은 지금까지 보고된 경골어류의 경우 한 개의 난막으로 둘러싸여 있는데 비해서 두 개의 난막으로 둘러싸여 있다는 것은 매우 중요한 빙어의 종특이성을 나타내며 난막의 미세구조적 특징들은 종을 분류하는 데 이용될 수 있다.

• Applied Microscopy
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• 제51권
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• pp.3.1-3.6
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• 2021

We examined the morphology of fertilized egg and ultrastructures of fertilized egg envelopes of dwarf rainbowfish (Melanotaenia praecox) belong to Melanotaeniidae using light and electron microscopes. The fertilized eggs were spherical with adhesive filament, transparent, demersal, and had a narrow perivitelline space and small oil droplets. The size of fertilized egg was 1.02 ± 0.18 mm (n = 30), and there were two kinds of adhesive filament on the fertilized eggs. The long and thick (diameter 12.22 ± 0.52 ㎛, n = 20) adhesive filaments were only at the area of animal pole, and short and thin (diameter 1.99 ± 0.23 ㎛, n = 20) adhesive filaments were around the long filaments. A micropyle was conical shaped with adhesive filament and located near the animal pole of egg. The outer surface of fertilized egg was rough side. Also, the total thickness of the fertilized egg envelope was about 7.46 ± 0.41 ㎛ (n = 20), the fertilized egg envelope consisted of two layers, an inner lamellae layer and an outer layer with high electron-density. And the inner layer was 8 layers. Collectively, these morphological characteristics and adhesive property of fertilized egg with adhesive filaments, and ultrastructures of micropyle, outer surface, and section of fertilized egg envelope are showed species specificity.

• Applied Microscopy
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• 제47권2호
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• pp.70-74
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• 2017

In the case of genus Nothobranchius, Nothobranchiidae, the morphology of fertilized eggs and ultrastructures of fertilized egg envelopes have been reported in only two fishes. Therefore it is hard for sure to these morphological characteristics show genus specificity because of lower research samples. So, we studied the morphology of fertilized egg, and compared the ultrastructures of outer surface, micropyle, and section of fertilized egg envelopes under the light and electron microscopes from the other two species, Nothobranchius foerschi and Nothobranchius rachovii, Nothobranchiidae to find out whether these structures have the species specificity or not. Both fertilized eggs were spherical, demersal and adhesive, and have a large oil droplet. The adhesive whip-like structures were distributed on the outer surface of egg envelope, and a micropyle located on the animal pole. The fertilized egg envelope consisted of two distinct layers: an outer electron-dense layer with adhesive structures and an inner lamellae layer in both species. The external shapes of fertilized egg and ultrastuctures of outer surface, micropyle, and section of fertilized egg envelope have same structure including results before. Our data indicate that these morphological characteristics of fertilized egg and fertilized egg envelope show genus Nothobranchius specificity.

• Applied Microscopy
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• 제43권1호
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• pp.14-20
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• 2013

The leopard danio, Danio rerio var. frankei is a spotted color morph of the zebrafish, Danio rerio caused by a pigment mutation. The structural differences of fertilized egg and egg envelope are poorly documented. To clarify this, we compared the fertilized egg morphology and ultrastructures of surface structures, the micropyle and the cross section of fertilized egg envelopes of zebrafish and leopard danio, variation species of zebrafish using a light and electron microscopes. Although the fertilized egg sizes were different, the external shapes of the fertilized eggs of two species couldn't be differentiated under the light microscope. The characteristics of fertilized eggs, such as a spherical shape, a non-adhesive quality and a large perivitelline space, were shown to be related to spawning habit. In ultrastructure of fertilized egg envelope, there is no morphological difference of micropyle between two species. By contrast, the ultrastructure and the numbers of knob-like structures and semihemisphere-like structures per unit area on the outer surface, and the number of lamellae of inner layer on the fertilized egg envelope section displayed definite species specificity. Collectively, our data indicate that the ultrastructure of fertilized egg envelope in the zebrafish could be differentiated by species variation.

• 한국수산과학회지
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• 제46권6호
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• pp.957-965
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• 2013

This study simulated the egg vertical distribution of mackerel Scomber japonicus in Korean waters using general numerical models. All eggs were spawned naturally by raising broodfishes (May-June 2013), and the egg specific gravity was measured by a density-gradient column. CTD surveys provided environmental data (e.g., temperature and salinity) in May near Jeju Island, Korea. The egg specific gravity during the early stages ranged from 1.0203-1.0211. In general, the fertilized eggs showed a gradual decline in egg specific gravity until full development of the main organs, with a sudden increase just before hatching. Modeled egg vertical distributions were influenced more by wind speed than by egg buoyancy and vertical structure of the sea water. During calm and normal wind speeds, the eggs were distributed from the surface to 25-m depths. Under strong wind conditions (three times higher than the normal speed), the egg concentration on the surface decreased, and the egg distributional depth was deeper (~50 m).

• 한국가금학회지
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• 제21권1호
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• pp.1-19
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• 1994

난좌(卵座)의 구면(球面)과 난각(卵殼)의 구면(球面)이 계란(鷄卵)의 파각도(破殼度)에 미치는 영향(影響)을 구명(究明)코져 실험(實驗)을 실시(實施)하였던바 다음과 같은 결과(結果)를 얻었기에 보고(報告)하는 바이다. 1. 9개 국가(國家)(미국, 프랑스, 이태리, 태국, 일본, 네델란드, 러시아, 한국, 스위스)에서 수집(蒐集)한 22종의 난좌형태(卵座形態)를 조사(調査)한 결과(結果), 우리 나라의 난좌(卵座)를 제외(除外)한 8개 국가(國家)의 난좌(卵座)는 그 세부(細部) 형태(形態)가 모두 상이(相異)하였다. 2. 4개의 모형난좌(模型卵座)에서 파각도(破殼度)를 측정(測定)한 결과(結果) B형, D형이 가장 파격도(破格度)가 높은 결과(結果)였다. 앞으로 난좌(卵座)를 제조(製造)할시 계란(鷄卵)의 구면(球面)과 난좌(卵座)의 구면(球面)이 서로 알맞아 파각도(破殼度)를 높일 수 있는 본(本) 시험(試驗)의 B형과 D형으로 제조(製造)하는 것이 가장 바람직할 것으로 사료되었다. 난좌가 견고하다고 해서 파각도가 높아지는 것은 아니었다. 본(本) 실험(實驗)에 공시(供試)한 전체(全體) 계란(鷄卵)의 난각(卵殼) 두께 성적의 통계 처리 결과 유의성이 없었다(P>0.05). 3. 난좌(卵座)에 포장(包裝)되어 계란(鷄卵)이 수송(輸送)될 때, 그 계란(鷄卵)의 구면(球面)에 따라 난좌(卵座)의 형(型)이 얼마나 넓은 면적(面積)으로 감쌀 수 있느냐가 파각도(破殼度)를 좌우(左右)하는 중요(重要)한 관건(關鍵)임을 알 수 있었다. 따라서 난좌(卵座) 제조시(製造時) 상단부(上段部) 난중(卵重)이 하단부(下段部) 난좌(卵座) 내부(內部)의 계란(鷄卵)에 미치는 하중(荷重)을 고려해서 난좌(卵座)의 내부구면(內部球面)과 계란(鷄卵)의 외내부구면(外內部球面)이 알맞을 수 있도록 만들어야 할 것으로 사료(思料)되었다. 4. 현재(現在) 우리나라에서 실시(實施)하고 있는 것처럼 1개의 난좌형(卵座型)으로 대란(大卵), 중란(中卵) 및 소란(小卵)을 공통(共通)으로 사용(使用)하는 것보다는 난중(卵重)에 따른 적정(適正) 난좌(卵座)가 개발(開發)되어 사용(使用) 될 수 있는 방안(方案)도 강구(講究)되어야 할 것으로 사료(思料)되었다.