• Title/Summary/Keyword: larval growth

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The Larvae and Juvenile Development of Haddock, Melanogrammus aeglefinus Cultured in Atlantic Canada (Atlantic Canada 해산어 Haddock, Melanogrammus aeglefinus의 자치어 발생 단계)

  • Kim Chi-Hong;Im Jae Hyun;Johnson Stewart C;Hur Jun Wook;Park In-Seok
    • Development and Reproduction
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    • v.8 no.1
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    • pp.11-17
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    • 2004
  • The larvae and juvenile development of haddock Melanogrammus aeglefinus which is significant commercial fish living north Atlantic Ocean are described here. Larvae were reared in laboratory and sampled periodically for developmental study until 67 days after hatching. An increase in total length(TL) of fish indicated continuous growth, described by the growth expression Y=4.07 $e^{0.037}$( $R^{2}$=0.9978). The newly hatched pre-larvae was 4.9 mm in TL with ellipsoid yolk. In 16 days after hatching, larvae attained 6.8 mm in TL, and absorbed the yolk completely to become post-larval stage, but first heterotrophic food could be in 7 days after hatching already. Post-larval stage continued during 16~52 days after hatching with development of organs attachment. In 61 days after hatching with 41.3 mm in TL, the fries became a juvenile stage respectively having small teed lateral line, and a black blotch on the flank same as adults, but chin barbel was not developed yet. It was presumed that haddock changed food and ecological behavior after metamorphosis ken this time.e.

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Fecundity and egg viability of house fly exposed to insect growth regulators (성충에 처리한 IGRs계 살충제가 집파리의 산란과 불임에 미치는 영향)

  • Park, Chung-gyoo;Choe, Sang-young;Kim, Jong-shu;Kim, Doo-ho;Lee, Heung-su
    • Korean Journal of Veterinary Research
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    • v.39 no.3
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    • pp.602-608
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    • 1999
  • Two-day old house fly adults were exposed to six insect growth regulators, flufenoxuron, teflubenzuron, triflumuron, diflubenzuron, methoxyfenozide, tebufenozide, as a feed additive (milk+5% sugar+chemical) in the laboratory for 6 days. The number of eggs deposited by the exposed-adults, viability of the eggs, and $F_1$ larval development were checked. All the IGRs tested were found to have no adverse effect on the reproduction of house fly, except methoxyfenozide (210ppm). The most effective inhibitor to egg hatch was flufenoxuron, followed by teflubenzuron, triflumuron, and diflubenzuron. Exposure to flufenoxuron (over 5ppm), teflubenzuron (over 25ppm), triflumuron (over 125ppm), and diflubenzuron (over 125ppm) reduced egg hatchability to 0 to 1.3%, but lower concentrations of these IGRs were less effective (6.3 to 46.3% egg hatchability). Almost all the larvae emerged from eggs deposited by the adults exposed to diflubenzuron (62.5ppm) and teflubenzuron (12.5ppm) failed to develop into pupae, causing total mortalities of 98% and 100%, respectively. However, two IGRs, methoxyfenozide and tebufenozide, did not inhibit egg hatch and $F_1$ larval development, except methoxyfenozide (210ppm) treatment These results suggest that these 4 IGRs may be used in the development of autosterilization system for house fly control. However, further work is required to develop delivery systems capable of transferring an effective dose to the fly under field conditions.

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Otolith Microstructural Organization in the South Georgia Icefish Pseudochaenichthys georgianus (Channichthyide) and Cautious Considerations on How Otoliths Can Provide Clues on a Species' Distribution and Migration in Antarctic Waters

  • Traczyk, Ryszard;Meyer-Rochow, Victor Benno
    • Ocean and Polar Research
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    • v.44 no.1
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    • pp.39-59
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    • 2022
  • How in the Antarctic icefish, generally, and Pseudochaenichthys georgianus, in particular, otoliths increase in size and build new material as the fish ages and passes through different life phases is largely unexplored. Morphometric details of 3418 otoliths of Ps. georgianus from S. Georgia and 318 from S. Shetland, were processed and proportions of the amounts of collagen and aragonite removed by EDTA were determined for different age groups. Microstructural investigations showed that characteristics of the 3-dimensinal collagen net are the reason for the radial direction and orientation of the aragonite needles of approximately 1.0 ㎛ in length in larval and 2.3 ㎛ in length in adult specimens. Earlier generated increment layers from the primordial centre (PC) in the dorsal direction restrict those of the secondary centre (SC), causing new growth layer accretion in different directions. In the otoliths of larval Ps. georgianus, aragonite layers are 0.89 ㎛ wide while in juveniles and adults they measure 1.45-2.86 ㎛. Otoliths change from a sphere shape in the larvae to a longish object of irregular outline in the older stages. It is tentaively suggested that the observed otolith shape differences at distinct growth stages are due to physical effects related to swimming speeds at particular water depths and locations. To confirm that otoliths, apart from being useful for age analyses, could also serve to establish correlations between developmental stage and the oceanic environment the fish spend time in, further analyses using additional species and state-of-the-art methods like µCT imaging to evaluate otolith volumes and shapes are required.

Role of oyster mushroom as an alternative fermentation source in the growth of white-spotted flower chafer(Protaetia brevitarsis seulensis) (사료 발효원으로 느타리버섯 종균이 흰점박이꽃무지 생육에 미치는 영향)

  • Mi-Hye Kim;Jang-Woo Park;Mi-Jung Kim;Jung-Joon Park
    • Korean Journal of Environmental Biology
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    • v.39 no.4
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    • pp.471-478
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    • 2021
  • Effective microorganisms (EM), which are sources of fermentation byproducts in herbal medicine, were compared with oyster mushrooms(OM) to identify alternative larval feeds for white-spotted flower chafer (Protaetia brevitarsis seulensis). The nutritional composition of each fermented feed was analyzed. The content of crude protein, crude fat, and fiber was higher in the OM fermented feed, except for crude ash. No difference in nutritional content of larvae based on fermented feed was observed. A comparative weekly analysis of the live weights of larvae was based on the fermented feed used. The average weight was significantly higher in the feeds using EM and OM from third week of observation. The larval survival rate in the presence of fermented feed was 96.7% compared with 9.8% with non-fermented feed. The results suggest that fermented food source is essential for the growth of white-spotted flower chafer, and OM was a stable alternative to EM as a fermentation source for the survival of white-spotted flower chafer.

Bioconversion and growth performance of Hermetia illucens in single fruit by-products

  • Bonwoo Koo;Ji Yeong Park;Eunsun Kim;Yongsoon Kim;Kwanho Park
    • International Journal of Industrial Entomology and Biomaterials
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    • v.46 no.2
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    • pp.34-40
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    • 2023
  • As agricultural production increases due to population growth, agricultural by-products that are generated at all production stages increase commensurately. Black soldier fly (BSF) (Hermetia illucens) treatment has potential as an environmentally friendly process to combat the environmental pollution caused by agricultural by-products. This study examined the utilization of BSF larvae in the decomposition of the by-products of apples and mandarins, fruits commonly produced in South Korea. The BSF test larvae were fed apple pomace or mandarin waste, and the control larvae were fed calf feed. Larval weight and size were measured at 4-day intervals until larvae reached the pre-pupal stage. Larval development time, survival rate, and BSF fecundity rate were calculated for all three substrates. Waste reduction and bioconversion ratios were also calculated. The developmental time of larvae fed with apple pomace and mandarin waste was greater than that of the control larvae. The average weight of larvae fed with the fruit by-products was less than that of the control. There was no significant difference in the survival rate of BSF larvae or the fecundity rate of BSF between the substrates used in this study. BSF larvae decomposed 48.0% and 61.5% of apple pomace and mandarin waste, respectively. The bioconversion efficiency rates of BSF larvae fed with apple pomace and mandarin waste were 9.1% and 12.1%, respectively. These results indicated that decomposition of single fruit by-products by BSF larvae is an environmentally friendly and effective bioconversion process.

Effects of Water Temperature, Salinity, Rearing Density and Food Supply on the Growth and Survival of the Surf Clam, Tresus keenae Larvae (수온, 염분, 사육밀도 및 먹이공급이 왕우럭(Tresus keenae) 유생의 성장과 생존에 미치는 영향)

  • Kang, Han Seung;Kim, Chul Won
    • Journal of Marine Life Science
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    • v.3 no.2
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    • pp.67-73
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    • 2018
  • This study was conducted to investigate the influence of environmental factors such as water temperature, salinity, rearing density and feeding amount on the survival and development of larvae in surf clam, Tresus keenae. As a result of this study, the optimum conditions of larval rearing were as follows. The optimum range of water temperature is 20℃ to 24℃, the optimum salinity is 30 psu, the optimum rearing density is 5 ind./ml and the supply of mixed feed organism for larva rearing such as Isochrysis galbana, Chaetoceros simplex and Tetraselmis suecica is 10×104 cells/ml. The results of this study suggest that the optimum conditions of environmental factors in larval rearing of Tresus keenae contribute to productivity improvement through rapid growth and high survival.

Relative Growth of the Melanin Snail, Semisulcospira libertina libertina and Monthly Composition of Larval Stages in its Brood Pouch (다슬기 (Semisulcospira libertina libertina)의 상대성장과 보육낭 유생단계의 월별 조성)

  • CHANG Young Jin;CHANG Hae Jin;KIM Jae Jun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.2
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    • pp.131-136
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    • 2001
  • Relative growth and composition of larval development stages in brood pouch of the melania snail, Semisulcospira libertina libertina were investigated based on monthly field samples for a year. Total number of specimens examined was 1,200. Size values (mean$\pm$S. D.) of shell height (SH), shell diameter (SD), total weight (TW), meat weight (MW) and shell weight (SW) were $15.96\pm3.41\;mm$, $7.82\pm1.38\;mm$, $0.55\pm0.31\;g$, $0.24\pm0.15\;g$ and $0.39\pm0.23\;g$, respectively, Water temperature (WT) of the sampling site varied from $1.3^{\circ}C\;to\;22.5^{\circ}C$. Relative growth equations among SH, SD, TW, MW and SW of S. libertina libertina specimens pooled were as follows: SD=0,3583SH+2.1648 $(R^2=0.8391)$, $TW=0.0005SH^{2.4853}\;(R^2=0.8391)$,$MW:\;0.0005SH^{2.849}\;(R^2= 0.8391)$ and $SW=0.0004SH^{2.3798}\;(R^2=0.7057)$. Female S. libertina libertina had larvae in its brood pouch throughout the year, Average number of larvae in the brood pouch varied from $91\pm33(July)$ to $396\pm174\;(November)$, decreasing in spring and increasing in autumn. In the monthly composition of larval stage in the brood pouch, trochophore, pre-veliger, veliger and juvenile showed maximum as $66.7\%$ in May, $70.7\%$ in November, $60.9\%$ in February and $13.9\%$ in January, respectively. Percent composition of the juveniles decreased in spring and autumn. In conclusion, S. libertina libertina is likely to have two main parturition periods, March to May and September and October.

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Expression Patterns of Growth Related Genes in Juvenile Red Spotted Grouper (Epinephelus akaara) with Different Growth Performance after Size Grading

  • Mun, Seong Hee;You, Jin Ho;Oh, Hyeon Ji;Lee, Chi Hoon;Baek, Hea Ja;Lee, Young-Don;Kwon, Joon Yeong
    • Development and Reproduction
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    • v.23 no.1
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    • pp.35-42
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    • 2019
  • Fish shows great difference in growth rate between individuals during larval development and early growth. This difference seriously reduces the production efficiency in fish culture. Growth hormone (GH)/Insulin-like growth factor 1 (IGF1) system is said to play some pivotal roles in fish growth. In this study, we investigated differences of GH, IGF1 and GHR gene expressions in juvenile red spotted grouper (Epinephelus akaara) with different growth performance. Red spotted groupers were reared under the same environmental condition (water temperature $24{\pm}1^{\circ}C$, natural light) for 96 days after hatching. They were divided into 3 groups by size (fast growing, middle growing and slow growing groups: FGG, MGG, and SGG, respectively). RNA was extracted from the brain, liver and muscle tissues from each group, and target gene expression was examined by real-time PCR. In the brain with pituitary gland, expression of GH gene in FGG was significantly higher than the expression in SGG, but the expression of IGF1 and GHR genes in the muscle was highest in SGG. Difference of GHR and IGF1 mRNA in the liver between groups with different growth performance was less clear than that in other tissues, although level of IGF1 mRNA was higher in SGG than in MGG. These results suggest that hormonal governing of growth is not the same in fast growing and slow growing fish, and size grading could cause a shift of hormonal state and growth pattern in this species.

Development of Eggs, Larvae and Juvenile of the Korean Bullhead, Pseudobagrus fulvidraco (Richardson) reared in the laboratory (동자개의 형태발달과 성장특성)

  • Han, Kyung-Nam;Nam, Ki-Bong;Jeong, Choong-Hoon
    • Korean Journal of Ichthyology
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    • v.13 no.1
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    • pp.74-84
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    • 2001
  • The early developmental stages, growth and morphological changes of the Korean bullhead, Pseudobagrus fulvidraco, were studied from a series of reared specimens. Details of the early developmental stages are illustrated with special reference to morphological transformations. Egg and sperm of Korean bullhead were obtained from mature adults under hormonal treatment, fertilized artificially, and incubated in the aquarium. The incubation period of fertilized eggs was 55 to 66 hours at a temperature of 24.9${\pm}$0.34$^{\circ}$. Larvae were fed successively with Artemia salina and Daphnia magna for 2 to 15 days and artificial food after 20 days. Fertilized eggs were adhesive and spherical with a diameter of 2.04mm(n = 100). The mean total length of newly hatched larvae was about 4.92${\pm}$0.33 mm. Mouth opening occurred on one-day-old yolk-sac larvae, and initial feeding was observed on the third day after hatching. The morphological transitions from larvae to juvenile and juvenile to young stages occurred when the fish reached about 17 mm in total length (about 13days after hatching) and about 32 mm in total length (about 30 days after hatching), respectively. Many changes in proportion of body parts to total length were observed at about 7~8 mm and 30~32 mm, corresponding to the transformations from larvae to juvenile and from juvenile to young, respectively. In comparing relative growth of each body part against total length, those characteristics related to head parts showed positive growth in the pre-larval stages, while those concerning mobile abilities showed positive growth in the post-larval stage.

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DEVELOPMENT, GROWTH, AND RELATIONSHIP BETWEEN TEMPERATURE AND METAMORPHOSIS RATE OF THE EARLIER LARVAE ON MACROBRACHIUM ROSENBERGI (DE MAAN) (Macrobrachium rosenbergi (De Maan)의 초기유생의 성장 및 수온과 변태와의 관계)

  • KWON Chin Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.7 no.2
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    • pp.52-62
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    • 1974
  • The fresh water prawn, Macrobrachium rosenbergi (De Maan) is a very common species in Info-pacific region inhabiting both fresh and brackish waters in low land areas, and especially abundant in the lower reaches of most rivers which are influenced by seawater, It is one of the largest and commercial species of genus Macrobrachium. As a place of the researches to clear the possibilities of transplantation and propagation of this species in the Far East region the larval development, growth, optimum temperature and metamorphose rate up to first post larvae in aquaruim are cleared under the conditions of salinity $6.58-7.05\%_{\circ}$ Cl, pH 8.0-8.2, the rate of flow 0.3 liter per minute and illumination 3000 lux. Temperature ranged from 27.5 to $28.7^{\circ}C$ during the period of earlier larval development. For the study oil the relationship between temperature and metamorphose rate from zoea to first post larvae, the temperatures in experimental tank were $22.2^{\circ}C\pm1$, $26.1^{\circ}C\pm0.85$, $28.1^{\circ}C\pm0.34$, $30.4^{\circ}C\pm0.66$, $33.7^{\circ}C\pm0.66$, $33.7^{\circ}C\pm0.38$ and $36.8^{\circ}C\pm0.26$. During the work, food used for the larvae was Artemia salina nauplius in the filter-circulation aquariums. This species metamorphosed to the first post-larvae through eleven zoea stages, and the characters of each larval stage are described and optimum temperature for metamorphosis rate and survivals to the first post larvae is $28.1^{\circ}C\pm0.34$.

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