• Title, Summary, Keyword: egg sac

Search Result 83, Processing Time 0.04 seconds

The Survival Rate and the Rate of Attached Egg Sac for Female Tigriopus japonicus Exposure to 4-nonylphenol (4-Nonylphenol에 노출된 Tigriopus japonicus 암컷의 생존율과 포란율)

  • Kwak Inn-Sil;Park Myung Ok;Lee Wonchoel
    • Korean Journal of Environmental Biology
    • /
    • v.23 no.2
    • /
    • pp.129-134
    • /
    • 2005
  • The aim of this study was to evaluate the attach rate and survival rate for the female harpacticoid Tigriopus japonicus response to 4-nonylphenol, known endocrine disrupter. The organisms were sampled by net sweeping on the Jeju Island in April, 2004 were reared in the laboratory condition. As the concentrations increased, the mortality was slowly increased. The first day for appearing dead individuals was clearly different between control conditions and treated conditions. When the female with egg sac was moved to experimental conditions for the adaptation, the female was dropped the egg sac from the body and then reproduced the egg sac into four to five days. Usually the female in control group recovered egg sac but that in the treated group made egg sac between $89\%\;and\;95\%$ on exposed individuals. The dead individuals for control conditions were showed on ten days after treating chemicals while those for treated conditions were appeared four to six day after exposure to chemicals.

고려인삼의 자성배우형성에 관한 연구

  • 한창열
    • Journal of Plant Biology
    • /
    • v.6 no.2
    • /
    • pp.3-6
    • /
    • 1963
  • As a part of embryological studies of Panax ginseng, megasporangium and megagametophyte formations were investigated. Ovule is found to be auatropous. Small-sized nucellus is surrounded by thick layered single integument. As the embryo sac develops, the nucellus along with some parts of the inner epidermis of integument disintegrates and completely disappers at flowering stage. Embryo sac takes the type of typical Polygonum although antipodal cells disappear and polar nuclei fuse to form secondary nucleus before fertilization. Mature embryo sac consists of egg apparatus and large secondary nucleus lying adjacent to the egg. Besides the normal ovule, tiny incomplete ovule develops near the base of style. Frequently two normal ovules are formed in a single locule. Chromosome number counted is PMC is n=24.

  • PDF

Ultrastructure of Fertilized Egg Envelope in the Tomato Clown Anemonefish, Amphiprion freatus (Pomacentridae : Marine Teleostei) (해산 경골어류 자리 돔과, Tomato Clown Anemonefish (Amphiprion frenatus)의 수정란 난막 미세구조)

  • Kim, Dong-Heui;Reu, Dong-Suck;Deung, Young-Kun
    • Applied Microscopy
    • /
    • v.28 no.3
    • /
    • pp.273-282
    • /
    • 1998
  • Ultrastructure of fertilized egg envelope in the tomato clown anemonefish (Amphiprion freatus) was examined by mean of light, scanning and transmission electron microscopies. The fertilized egg of tomato clown anemonefish was of non-transparent, ellipsoidal, adhesive and non-floted type, and there were numerous oil droplets in the yolk sac and adhesive filaments in the area of the animal pole. The outer surface of egg envelope was smooth. The fertilized egg envelope consisted of two distinct layers; a non-adhesive outer electron-dense layer and an inner layer, consisting of five horizontal low electron-dense lamellae alternating with the middle electron dense interlamellae.

  • PDF

Spawning and Egg Development of Sand eel(Hypoptichus dybowskii) (양미리 (Hypoptichus dybowskii)의 산란과 발생)

  • 이정용
    • Development and Reproduction
    • /
    • v.1 no.1
    • /
    • pp.91-97
    • /
    • 1997
  • In order to study the reproductive physiology of Sand ell(Hypoptichus dybowskii) catched at kangwon-do, Wooamjin Bay, spawning and egg development were investigated in April and May, 1996. The observed spawning period was from the middle of April to the end of May with the water temperature above $8^{\circ}$C. Body size and colouration were distinguished between male and female. The type of testicular structure is lobular, and the ovary is a pair of sac-sahaped covering with a fibromuscula capsule and comprising a mature egg of average 86. The unfertilzed egg are demersal and adhesive, and their diameter were 1.65-1.95 mm. the colour of yolk is light yellow and contained a lot of tiny oil globules. The average spawned egg was 62 in sargasso weeds. Hatching was observed in 12 days after fertilization with the water temperature of 14 ${\pm}1^{\circ}$C. The average size of larva after hatching was 6.85${\pm}$0.23mm in total length, and larva were containing yolk including globule.

  • PDF

Within0tree Disribution of matsucoccus thunbergianae on Pinus thunbergiana (해송에서의 솔껍질깍지의 벌레 수상분포 양식)

  • 박승찬
    • Korean journal of applied entomology
    • /
    • v.33 no.2
    • /
    • pp.114-121
    • /
    • 1994
  • Population densities of intermediate nymphs and egg saw of Matsucoccus thunbergianae, a major insect pest of Pinus thunbergiona in southern coastal area of Korean peninsula, were est~mated. Tree samples of ca. 10cm D.B.H. were collected from old infestation area and newly invaded area. The numben of plimaly branches per tree were not significantly different by the locality, but those of secondaly and smaller branches were smaller in old infestation area The numbers of intermediate nymphs per tree in old infestation area and in newly invaded area were 10.8 and 13.1 times more than those on the trunk, respectively Approximately between 4, 200 and 208, 500 nymphs per tree were estimated. Men secondaw and smaller bmnch samples collected from the basal part of middle crown height, or from the central or the basal part of lower crown height, the number of samples required for the emr range of 20% were 21 and 11 far 10-20cm and 20-3 crn long branches, respectively. Approx~mately 63.6% of egg sacs of the whole tree were on the trunk. The node/intemode bearing the largest branch had the highest egg sac density; including that, four adjacent nodes/intemodes had ca. 37% of egg saw on the trunk.

  • PDF

Breeding Habits and Egg Development of the Goby, Micropercops swinhonis (좀구굴치 ( Micropercops swinhonis ) 의 산란습성 및 초기 난발생)

  • Kim, Ik-Soo;Byung-Jik Kim
    • The Korean Journal of Ecology
    • /
    • v.19 no.5
    • /
    • pp.477-486
    • /
    • 1996
  • The freshwater goby, Micropercops swinhonis ($G\"{u}nther$) was studied on the spawning behavior and egg develeopment at the two areas of Chollabukdo, Korea from March to May 1995. Egg mass attached to a layer under stones and the inner wall of waterplant, Cyperus. Spawning behavior was divided in to 1) premating stage: selecting spawning sites and formation of territory by male, 2) mating stage: enticement with zigzag-like dance and intermittant shaking of head by male and fertilization, 3) postmating stage: fanning, guarding and cleaning the nest by male. The eggs were transparent and spherical in shape, measuring $0.9\times1.4mm$ with yellowish yolk sac and many oil globules. Hatching began in about ten days after fertilization at water temperature $16~20^{\circ}C$. The newly hatched larvae were 3.8~4.0 mm in total length with 30 myomeres and their mouths and anuses were opened. Melanophores appeared at the air-bladder and the ventral side of caudal region.gion.

  • PDF

Congenital Malformation Caused by Bisphenol A in Developing Chick Embryo

  • Kim Su Won;Kim Jin Sik;Ryu Hye Myung;Nam Jin Sik;Cheigh Hong Sik;Min Byung Tae;Park Soo Hyun;Yoo Min
    • Biomedical Science Letters
    • /
    • v.10 no.4
    • /
    • pp.397-401
    • /
    • 2004
  • We have examined congenital malformation in developing chick embryo caused by endocrine disruptor, bisphenol A (BPA). We injected BPA into the air sac of developing egg on day 4 of incubation. BPA-treated group with a concentration of 10 ㎍/egg showed a little decrease on their body length compared to the untreated group. But the group treated with 50㎍/egg revealed severe malformation in eyeballs and bills. The group treated with 100㎍/egg could not continue their development after few days of incubation. These results indicate that BPA clearly inhibits the normal development in chick and it should be toxic to the developing fetus at early stage and in various tissues. The study should contribute to the understanding of toxic effect of BPA in developing human fetus when exposed to the BPA.

  • PDF

Developmental Characteristics of Eggs and Yolk Sac Larvae of Korean Striped Bitterling, Acheilognathus yamatsutae (Cyprinidae), Spawning in Mussels

  • Song, Ho-Bok;Son, Yeong-Mok
    • The Korean Journal of Ecology
    • /
    • v.28 no.4
    • /
    • pp.193-198
    • /
    • 2005
  • This study investigated the characteristics of the eggs and yolk sac larvae of Korean striped bitterling, Acheilognathus yamatsutae, spawned and grown In mussels. The number of eggs in the ovary was small ($358{\pm}108$ SD). The eggs were oval and large, and the formation of the perivitelline space was narrow. The eggs were hatched at only 41 hours after fertilization but the hatched larvae were underdeveloped. The development of yolk projection and minute tubercles on the skin surface was notable, along with the vividly moving tail in the hatched larvae. The yolk projection and minute tubercles were disappeared upon enhancement of the motor ability of the larvae was enhanced. The formation of eyes and body pigments of the larvae was relatively delayed in comparison with that of other cyprinid larvae. After completely consuming the yolks the larvae escaped from the mussel for free swimming and exogenous feeding.

Embryogenesis in the Octopus minor (낙지(Octopus minor)의 배 발생)

  • Kim, Dong-Soo;Kim, Jae-Man
    • Development and Reproduction
    • /
    • v.10 no.2
    • /
    • pp.135-140
    • /
    • 2006
  • The small octopus(Octopus minor), a species in the cephalopod class spawns the fewer eggs compared with its relatives such as Octopus vulgaris and Octopus ocellatus and exerts special efforts in nursing eggs hiding in the deep cave beneath the mud flat. Correspondingly, its embryogenic process had been hardly observed. In this study, we induced the small octopus to spawn its eggs in the artificial spawning tube and to nurse the developing embryos under the periodical observation. The early embryogenic change in the fertilized eggs was appearance of blastodisc on the animal pole at 4 days after spawning. A mass of rudiments of several organs developed in the middle of the yolk sac at 28-th day and it moved gradually toward the animal pole. At 38 days after spawning, two eyes appeared on the head and the trunk with heart developed on the apical part of the yolk sac. At 45-th day of embryonic development, the trunk and head occupied a half of the egg capsule and consequently the yolk sac was reduced to a half of its original size. Two eyes became prominent at the bottom of the trunk with several spots at day 60. Embryonic development was completed at about 80 days after spawning and the arms stuffed the lower half of egg capsule. The young fry squeezed out of the egg capsules with their long and slender arms first and mantles later. Soon after hatching, it swam actively and squirted ink.

  • PDF

Effect of Bacillus spp. Having Gelatin Decomposing Activity on Root-knot Nematode, Meloidogyne incognita on Pepper (젤라틴 분해력이 있는 Bacillus균의 고추 고구마뿌리혹선충에 미치는 영향)

  • Kim, Jin Han;Park, Chan Sun;Kim, Young-Ho;Kim, Yu Ri;Lee, Seung Woong;Rho, Mun Chual
    • The Korean Journal of Pesticide Science
    • /
    • v.20 no.4
    • /
    • pp.375-379
    • /
    • 2016
  • This study investigated the decomposing activities on gelatin and egg sac of root-knot nematode (Meloidogyne incognita). Ten Bacillus isolates (KRB-1~10) isolated from the soils of Mt. Naejang. Among them, KRB-5, 9, and 10 showed decomposing activities, and identified as Bacillus subtilis KRB-5, Bacillus amyloliquefaciens KRB-9, and KRB-10 by 16S rRNA sequence analysis, respectively. Under pot experiments using pepper, 100-fold diluted culture broth of three isolates reduced the number of egg sac on roots collected 60 days and 90 days and increased the growth of aerial part compared with the group only treated with Meloidogyne incognita. Especially, the group treated B. subtilis KRB-5 was superior in the growth of pepper. These results suggest that the B. subtilis KRB-5 can be used to control the root-knot nematode on pepper.