• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.267-273
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• 2014

This research has carried out to make a data base of taxonomic research. That Data base explains about spawning behavior, egg development, and morphologic development of variable sabretooth blenny. Fertilized egg was demersal egg which is white and opaque. The number of oil glouble were 10~11, and the size of egg was 0.90~1.43 mm (average rate $1.11{\pm}0.23mm$, n=10). Breeding water temperature was $25.5{\sim}28.5^{\circ}C$ (average rate $27.0^{\circ}C$), and salinity was 32.5~33.5‰ (average rate 33.0‰). After 24 hours from 2 cells, the process of egg development was reached to Blastula stage. Moreover, after 330 hours from 2 cells, nostrils and eyes were formed. Egg membrane was pierced by the head, and the hatch began. After the hatch, postlarvae had 2.59~3.02 mm (average rate $2.81{\pm}0.25mm$, n=5) of whole length, and the mouth and anus were opened. Yolk sac and oil glouble were absorbed. After three days from hatch, prelarvae were 3.02~3.07mm(average rate $3.04{\pm}0.04mm$) of whole length, and caudal fin was grown with round shape. After 13 days from hatch, prelarvae had 3.04~3.20 mm (average rate $3.12{\pm}0.11mm$) of whole length, and they could eat food with upper jaw and bottom jaw.

• Ocean Science Journal
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• v.40 no.1
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• pp.11-16
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• 2005

Correction factors based on the catch ratios of egg and larval densities in the southern waters of Korea were estimated for anchovy Engraulis japonica. This was undertaken in order to adjust ichthyoplankton data from different sampling methods, gear types and time. Samples were collected during ichthyop1ankton surveys in Korean waters from 1983 to 1994. The ratios for egg densities obtained in vertical tows with a NORPAC net (ring $\Phi$, 45 cm) compared to those obtained in oblique tows with a KOB net (ring $\Phi$, 80 cm) were 0.86 (CV = 0.65), 1.22 (CV = 0.36), and 0.93 (CV = 0.42) for early, middle, and later developmental stages, respectively. The ratios for larval densities for vertical and oblique tows varied depending on size. For yolk-sac and small larvae (< 4 mm), the ratios were 3.08 (CV = 0.45) and 1.98 (CV = 1.34), while those of 4-6 mm, 6-8 mm, and 8-10 mm larvae were 0.44 (CV = 1.31), 0.45 (CV = 1.70), and 0.56 (CV = 2.50), respectively. Ratios of day/night densities for larvae of 4-10 mm lengths were lower (0.01-0.06) in offshore catches than values obtained in coastal areas (0.440.46) and similar values (0.16-0.04) for vertical and oblique tows. Our results indicated that vertical towing is more efficient for sampling early life stages (from eggs to larvae less than 4 mm long), while oblique towing is more efficient for larvae longer than 4 mm due to depth preferences for each developmental stage (e.g., changes in egg buoyancy and vertical migration oflarvae).

• Fisheries and Aquatic Sciences
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• v.24 no.11
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• pp.375-382
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• 2021

In this study, the reproductive behavior and embryonic and larval development of the short ninespine stickleback Pungitius kaibarae was described and illustrated based on observations during spawning, hatching, and larval rearing trials. Adult P. kaibarae were collected downstream in Jinhae during the reproductive season (April-May). Males had nuptial coloration on their entire black bodies, with blue dorsal spines and yellow eyes, whereas females had a brown spotted pattern on their bodies. Males built nests on the stems of water weeds and attracted females. Fertilization occurred in the nest immediately after spawning, and males guarded the eggs until hatching. The fertilized eggs of P. kaibarae were spherical, demersal, adhesive, and transparent, and each egg measured 1.43 ± 0.07 mm in diameter. The morula, blastula, and gastrula stages, as well as hatching began at 5, 18.5, 21.5, and 96 post fertilization (HPF), respectively, at 20.0 ± 0.5℃. The newly hatched larvae had a total length (TL) of 5.67 ± 0.50 mm, with a yolk volume of 0.583 ± 0.059 mm³. Their mouths and anuses had not yet opened. At 2 days posthatching (days post hatching, DPH), the yolk was completely absorbed and the larvae began to feed exogenously. Pigmentation was observed in freshly hatched larvae 4 h after hatching, with the presence of eight areas with a dotted pattern on the dorsal surface of the larvae and dispersed spots on the head and yolk sac. At 30 DPH, the TL of the juveniles was 21.34 ± 1.70 mm. The nest area and number of eggs were 259.56 ± 101.39 mm² (75.18-506.04) and 155.33 ± 114.12 (0-437), respectively.

• Korean Journal of Poultry Science
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• v.37 no.2
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• pp.159-165
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• 2010

Field strains of Ornithobacterium rhinotracheale (OR) were tested on their virulence in specific pathogen free (SPF) embryonated chicken eggs and 3-week-old broilers. When infected with three different OR isolates (OR-161, OR-240 and OR-295) through yolk sac infection route, all strains appeared to be highly pathogenic with responsible mortality 66% and 100% within 12 days post infection (DPI). To test the virulence of OR in the commercial broilers, 3 week-old broilers were grouped depends on the inoculation route of OR isolate (OR-295) through five different infection routes; group 1 (IT: intratracheal), group 2 (IM: intramuscular), group 3 (IV: intravenous), group 4 (aerosol) and group 5 [Mixed: NDV (LaSota)+OR aerosol]. Within 5 to 7 days after inoculation, only broilers given NDV+OR were slightly depressed and coughing, and had mild facial redness. Grossly, foamy and yellow-white yogurt like exudate in the air sacs, predominantly in the abdominal air sacs was present. In histology, infiltration of the air sac epithelium and lamina propria by macrophage and polymorphonuclear granulocytes was seen with cell debris and inflammatory cells, correlated with the presence of OR antigen, as demonstrated by immunohistochemistry. Field strains of OR were able to induce high mortality in the embryonated chicken eggs, whereas broilers were less susceptible to OR infection. Interestingly, in the absence of NDV infection, the four groups of OR single infection only different route showed minimal and temporary microscopic air sac lesions. Thus, Newcastle disease virus (LaSota strain) showed triggering effects on the OR infection in chickens.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.49-54
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• 2017

We collected and reared Theragra chalcogramma walleye pollock brood-stock for use in natural spawning tests and undertook to obtain domestic pollock via fertilized egg capture, development of fertilized eggs, and absorption of yolk sac after hatching. Whole pollock were caught with trammel and set nets and immediately placed in a deep-sea water tank. Adults were the most common pollock age group (43.0%; n = 86) among the 254 pollock captured in March 2014 with 57.9% (n = 147) being captured off Southern Gosung, Korea. The main spawning period of pollock is February (spawning phase of 91% of pollock). From the deep-sea tank, we collected 1640 mL of naturally fertilized eggs (~820,000 eggs) from 12 spawning events occurring between February 4 and 22 2015. The floating/ live eggs were maintained in deep-sea water tanks at $5.5{\pm}0.2^{\circ}C$. Egg size was $1.5{\pm}0.03mm$. Six hours after fertilization the eggs were at the 2 cell stage, and the eggs hatched approximately 340 hours after collection. At hatching, larval length and yolk sac area were $5.2{\pm}0.25mm$ and $9.5{\pm}1.00mm^2$ (100%), respectively. Four days after hatching, the yolk sac area was $2.2{\pm}0.53mm^2$ ($23.1{\pm}5.55%$). This is the first report of collection of naturally fertilized eggs from pollock and their subsequent hatching while held in an indoor deep-sea water tank. The results suggest that such collection could assist in the recovery of pollock resources and the possibility of domestic rearing of cultivated larvae.

• Molecules and Cells
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• v.39 no.10
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• pp.768-775
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• 2016

The Arabidopsis female gametophyte contains seven cells with eight haploid nuclei buried within layers of sporophytic tissue. Following double fertilization, the egg and central cells of the gametophyte develop into the embryo and endosperm of the seed, respectively. The epigenetic status of the central cell has long presented an enigma due both to its inaccessibility, and the fascinating epigenome of the endosperm, thought to have been inherited from the central cell following activity of the DEMETER demethylase enzyme, prior to fertilization. Here, we present for the first time, a method to isolate pure populations of Arabidopsis central cell nuclei. Utilizing a protocol designed to isolate leaf mesophyll protoplasts, we systematically optimized each step in order to efficiently separate central cells from the female gametophyte. We use initial manual pistil dissection followed by the derivation of central cell protoplasts, during which process the central cell emerges from the micropylar pole of the embryo sac. Then, we use a modified version of the Isolation of Nuclei TAgged in specific Cell Types (INTACT) protocol to purify central cell nuclei, resulting in a purity of 75-90% and a yield sufficient to undertake downstream molecular analyses. We find that the process is highly dependent on the health of the original plant tissue used, and the efficiency of protoplasting solution infiltration into the gametophyte. By isolating pure central cell populations, we have enabled elucidation of the physiology of this rare cell type, which in the future will provide novel insights into Arabidopsis reproduction.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.6
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• pp.471-477
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• 2008

Development of egg, larvae and juveniles for the Pacific mackerel, Scomber japonicus are described following natural fertilization in the indoor tank of $25^{\circ}C$ water temperature. Following a routine hormone treatment technique for the brood stock, male and female mackerels were artificially matured by intramuscular injections of LHRHa at a dosage of $400{\mu}g/kg$ body weight (BW)+Domperidone at a dosage of $4{\mu}g/kg$ body weight (BW) to induce maturation in a separate aquarium and induced natural spawning. Fertilized eggs were ca. 1.0 mm in diameter; spherical in shape with a single oil globule; pelagic and non-adhesive. Hatching occurs 41 hours after fertilization at $23-24^{\circ}C$. The newly hatched larvae was 3.03 mm in average total length (ATL), the mouth and anus were not open, oil globule located in posterior end of yolk sac, and preanal length was 42.8% of TL. The larvae measuring 2.89 mm ATL, almost absorbed yolk sac and oil globule material in 2 days after hatching, in which the mouth and anus were open. Melanophores, branch or star in shape were observed on the top of head, peritoneal region and along the ventral contour. In 13 days after hatching, the larvae was 6.88 mm ATL, its posterior end of notochord began to flex upward, finfold of caudal fin appeared, jaw teeth were already formed. In 19 days after hatching, the larvae was 7.71 mm ATL completed only caudal fin rays (9+8), and preanal length was 49.4% of TL. In 37 days after hatching, the larvae was 27.4 mm ATL already completed all the fins, and preanal length was 59.9% of TL.

• Korean Journal of Plant Taxonomy
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• v.32 no.4
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• pp.467-480
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• 2002

The development of the female gametophyte of Corydalis albipetala, C. ambigua, C. filistipes, C. nobilis, C. solida, C. ophiocarpa have been comparatively investigated using laser scanning confocal microscope (LSCM) and light microscope. An archesporium was originated from one of the outmost parietal cells beneath the one-layered epidermis of protuberant nucellus, and acted directly as a megaspore mother cell (MMC). These species had linear tetrads after successional meiotic division during the megasprogenesis. A functional megasprore developed from one of the tetrad in the chalazal end, and the rest three being degenerated. The developmental type of the female gametophyte was monosporic in accordance with the Polygonum type. Prior to anthesis the female gametophyte was organized. So mature embryo sac was comprised a three-celled egg apparatus, three large antipodals were developed from the apex of each antipodal cell, and extended toward micropylar end to be contacted with egg apparatus. Two synergids were usually observed as degenerated condition, and in this time the apices of antipodal haustoria were connected with the degenerated synergids. The developmental characteristics of seven-nucleate female gametophytes were common in all the species investigated. But the shape of mature embryo sac was ovoidal in C. albipetala, C. filistipes, C. ophiocarpa and C. solida, reflexed in C. ambigua, and rather flattened ovoidal in C. nobilis. Also, the type of megasporangium was anatropous in all the species except C. ambigua with campylotropous ovule.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.368-374
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• 1986

Liparis ingens (Gilbert et Burke) is a demersal fish belonging to Liparidae, widely distributed in the coastal waters of the east coast of Korea. On January 16, 1986, mature adults of Liparis ingens were captured by a demersal gill net near Chongdongchin-ri, Kangwon-do, Korea. The authors stripped eggs and milt, and fertilized on the ship. The eggs were incubated and the larvae were reared in laboratory. The eggs of this species are demersal and adhesive, and are pale yellow, containing many oil globules. Egg diameters were varied from 1.55 to 1.65 mm. The hatching took place in ca. 747 hours after fertilization at the water temperature of $7.09{\sim}10.99^{\circ}C$ and salinity $30.62{\sim}33.98\%0$. The newly hatched larvae were elongate in shape and $4.40{\sim}4.85mm$ in total length with $12{\sim}13$ (abdominal)+40(caudal)=$52{\sim}53$ myomeres. Many melanophores were distributed on the lower jaw, pectoral fins, yolk sac, and ventral line of the tail part. Three days after hatching, the larvae reached 5.15 to 5.25 mm in total length, and the yolk sac was almost absorbed. Some melanophores appeared on the back of auditory vesicles. Seven days after hatching, the larvae attained $5.75{\sim}5.85mm$ in total length.

• Journal of Aquaculture
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• v.12 no.1
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• pp.15-24
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• 1999

From January 1997 to May, the red marbled rockfish, Sebastiscus tertius (Barsukov et Chen) was reared in the laboratory, and observed the morphological characteristies of egg and development of larvae and juveniles. The egg is spherical in shape colorless and transparent, measuring 0.72~0.80mm in diameter (mean 0.75mm, n=50). The naturally bearing larvae were 3.79~3.97mm in total length with 7~8＋15~16=22~24 myomeres, and mouth and anus were open. Melanophores were present on the yolk of the larva and ventral margins of the tail. The 1~2 days after bearing larvae measured 3.90~4.13mm in total length, and transformed to postlarval stage, and yolk sac were completely resorbed. On the lower jaw melanophores were present. Total length of the larvae was 4.23~4.60mm in total length (11 days after bearing), number of elongated pectoral fin rays was 9~10, and melanophores distributed on the top of head, around the intestine tube, ventral margins of the tail and on the pectoral fin. In 21 days after bearing, the larva were 5.83~7.10mm in total length, and the caudal notochord flex $45^{\circ}$. Individuals of 9.80~12.36mm in total length (33 days after bearing) are regarded to have reached to the juvenile stage with all the fins were developed.