• Fisheries and Aquatic Sciences
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• 제11권2호
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• pp.98-102
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• 2008

Relationships between total length (TL) and fecundity, body weight and fecundity, ovary length and fecundity, and ovary weight and fecundity of hilsa shad, Tenualosa ilisha Hamilton, collected from Kuakata, Patuakhali, Bangladesh, were studied. During the sampling period, the fecundity of hilsa was found to range from 169,000 (fish TL=28.0cm, weight=250g) to 1,088,000 (fish TL=40.5cm, weight=955g) with a mean of $520{\pm}53{\times}1,000$. The number of eggs per gram of ovary for samples collected from the anterior, middle, and posterior regions of the ovary were also recorded, but no significant variation was found among ovary regions at the 5% level of significance. Fecundity increased with fish TL and weight. The regression equations obtained in arithmetic forms of relationships between TL and fecundity (F), body weight (BW) and fecundity, ovary length (OL) and fecundity, and ovary weight (OW) and fecundity were $F=-887,896+40,511{\times}TL(r=0.85)$, $F=67,577+755.44{\times}BW(r=0.85)$, $F=-562,070+87,668{\times}OL(r=0.75)$ and $F=124,815+6,596.7{\times}OW (r=0.84)$, respectively. The relationships between fecundity and TL, body weight, ovary length, and ovary weight were linear, and the 'r' values were highly significant (p<0.01). These results provide valuable data for the restoration of hilsa resources, which are economically important but have shown reduced productivity in nations adjacent to the Bay of Bengal.

• International Journal of Industrial Entomology and Biomaterials
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• 제8권2호
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• pp.217-219
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• 2004

Stimulation of fecundity following female antennal amputation has been reported for the first time in silkworm. Antennal amputation caused significant increase in fecundity in two newly evolved multivoltine silkworm breeds viz., BL 67 and 96A. This study indicated better chances for increasing egg yield and the increase in fecundity may be attributed to the action of some neurohormones. Significance of antennal amputation in silkworm has been discussed.

• 한국어류학회지
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• 제22권2호
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• pp.121-125
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• 2010

진해만에 산란회유한 대구 친어의 체장에 따른 포란수를 조사하기 위하여 거제수협 외포 위판장에서 산란기인 2008년 12월부터 2009년 2월까지 채집한 45개체의 대구 전장과 포란수를 조사하였다. 산란기 동안 최대 포란수는 520만개 (TL 74.0 cm), 최소 포란수 56만개 (TL 64.0 cm), 평균 포란수 212만개였다. 어체 전장범위별 비교에서는 전장 66~70 cm에서 평균 포란수 169만개, 71~75 cm에서 평균 포란수 260만개로 증가하였다. 진해만 대구는 전장 증가에 따라 포란수도 증가하는 것으로 나타났다. 산란기간 중 전기, 중기, 후기의 평균 포란수는 262만개, 196만개, 165만개로 전기에서 후기로 갈수록 감소하는 경향을 나타냈다. 또한 상대포란수도 포란수와 유사한 경향을 나타냈다. 한편 상대포란수와 체장과의 상관관계는 적은 것으로 나타났고 같은 전장에서 상대포란수가 316~935개로 폭넓게 나타난 것으로 보아 같은 어체 크기라도 진해만으로 산란회유하는 시기에 따라 포란수가 달라질 수 있음을 시사하고 있다.

• Fisheries and Aquatic Sciences
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• 제26권5호
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• pp.318-335
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• 2023

It is important to understand the biological aspects of fish for fishing management. This study was conducted from February through October 2021. A total of 1,629 fishes were collected using different fishing gears. The length-weight relationship is a power curve for all fishes and showed a significant (r² > 0.8). All fishes revealed a negative allometric growth pattern except Labeobarbus intermedius. Oreochromis niloticus (1.714 ± 0.009) was found in better condition than other fish species (analysis of variance [ANOVA], p < 0.05). The length at maturity was 24.0 cm and 25.4 cm total length (TL), 28.9 cm and 28.2 cm fork length, and 53.2 cm and 57.5 cm TL for females and males of O. niloticus, L. intermedius and Clarias gariepinus, respectively. Fecundity was ranged between 100-947 eggs/g with absolute fecundity (AF) of 468-3,832 eggs, 200-1,000 eggs/g with AF of 2,752-136,420 eggs, and 505-900 eggs/g with AF of 2,000-6,404 eggs for O. niloticus, C. gariepinus, and L. intermedius, respectively. Their respective mean fecundity was 1,490 ± 91, 23,330 ± 5,070, and 3,096 ± 273 eggs, respectively. Mean fecundity revealed a significant variation between size classes and species (ANOVA, p < 0.05). The fecundity length and fecundity-body weight relationships except (O. niloticus) of fishes were curvilinear while the gonad weight (GW)-fecundity relationship was linear for all fish species. The fecundity was moderately associated with increasing length than body weight, and GW for all fishes (r² > 0.6). In conclusion, a tangible management setup is required to sustain the use of fish in the reservoir.

• International Journal of Industrial Entomology and Biomaterials
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• 제17권1호
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• pp.157-163
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• 2008

Infection of pathogenic microsporidia, Nosema bombycis and Nosema mylitta (Chakrabarti and Manna, 2006) decreased egg production, fecundity, hatching % and increased sterile eggs in heavily infected mulberry silkmoth, Bombyx mori L. On an average a disease free moth laid upto 442.67 eggs with high hatching % (99.53) and less sterile eggs ($0.47{\sim}2.00%$). While an infected moth laid less number of eggs ($7.00{\sim}412.00$) with low hatching % ($32.437{\sim}98.643$) and high sterile eggs ($2.143{\sim}129.571$). Fecundity of disease free laying was highest (468.714) during season-1 then gradually decreased during season- 2 (414.000) to season- 3 (404.285). But fecundity of an infected laying was highest during season-2 and hatched eggs were lowest during season-2. Higher inoculums concentration of N. mylitta infected to 5th stage larva of mulberry silkworm drastically decreased the fecundity in season - 3 and lower inoculums concentration of N. bombycis decreased the fecundity in season-1 and 3. Season-3 was most effective season to decrease the fecundity and increase sterile eggs when both temperature and humidity were fluctuated from the optimum level.

• 한국어류학회지
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• 제21권4호
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• pp.239-246
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• 2009

본 연구는 돌가자미의 인공종묘생산을 위한 기초자료를 확보하고자 2003년 10월에 충남 격렬비역도 해역에서 자연산 어미를 채집하여 실내에서 자연산란을 유도하고 산란 특성과 포란수를 조사하였다. 실험에 사용된 어미는 암컷 12마리(전장 34.5~51.0 cm, 체중 540~2,200 g), 수컷 23마리(전장 29.0~38.0 cm, 체중 310~680 g)이었다. 난소의 발달은 12월부터 꼬리쪽으로 길게 확장되어 육안적으로 쉽게 확인되었다. 돌가자미 어미는 실내에 수용하여 3개월 후부터 산란을 시작하였으며, 2004년 1월 9일부터 3월 27일까지 77일간 이루어졌다. 산란기간 중 일장은 9.8~12.1시간으로 연중 가장 짧았으며, 수온은 $8.4{\sim}12.2^{\circ}C$이었다. 총 산란량은 19,844,000개였으며, 산란중기에 15,433,000개(77.8%)로 가장 산란량이 많았다. 총 산란량중 평균부상율은 50.4%, 수정률은 58.5%, 부화율은 55.6%, 부화자어의 정상 출현율은 93.8%이었다. 전장당 절대포란수의 총 난수는 전장이 커짐에 따라 증가되는 경향을 보였으며, 상대포란수(cm 당)의 총 난수도 전장이 커짐에 따라 증가되는 경향을 보였다. 체중당 절대포란수의 총 난수는 체중이 증가됨에 따라 증가되는 경향을 보였으나 체중당 상대포란수(g 당)의 총 난수는 체중이 증가됨에 따라 증가되나, 일정 체중 이상으로 커지면, 오히려 체중 증가에 따라 감소하는 경향을 보였다.

• International Journal of Industrial Entomology and Biomaterials
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• 제14권1호
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• pp.45-50
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• 2007

Ethanol extract of 20 botanicals in 3 concentrations i.e., 2.5%, 5% and 10% were evaluated for their efficacy to improve reproductive performance of mulberry silkworm (Bombyx mod L.) through feeding botanical enriched mulberry leaves during $2^{nd}$ day of $4^{th}$ age as well as $1^{st}$ and $3^{rd}$ day of $5^{th}$ age larvae. The preliminary screening was done by ranking the botanicals based on influence in most important reproductive contributing parameters such as single cocoon weight, effective rate of rearing, pupation rate, fecundity and recovery of eggs/kg cocoon. Five botanicals viz., Asparagus recemosus, Achyranthes aspera, Tribulus terrestris, Withania somnifera, Parthenium histerophorus ranked first were further evaluated at 8% 5% and 3% concentrations to confirm their effectiveness and standardize effective concentration. Among the rearing parameters, mature larval weight, shell ratio and number of cocoons/kg were not significantly influenced by the treatments. However, reproductive parameters such as effective rate of rearing (wt), pupation rate (%), fecundity (No.) and egg recovery (g)/kg cocoon were significantly (P<0.05) influenced by the botanicals. Higher fecundity and egg recovery were obtained on treatment with Withania somnifera irrespective of concentrations. However at 5% concentration, pupation rate, fecundity as well as egg recovery were found significantly higher than that of other concentrations, confirming its effectiveness for improving reproductive efficiency.

• The Plant Pathology Journal
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• 제32권3호
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• pp.260-265
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• 2016

We observed the changes in aggressiveness and fecundity of the anthracnose pathogen Colletotrichum acutatum on hot pepper, under the ambient and the twice-ambient treatments. Artificial infection was repeated over 100 cycles for ambient ($25^{\circ}C/400ppm$ $CO_2$) and twice-ambient ($30^{\circ}C/700ppm$ $CO_2$) growth chamber conditions, over 3 years. During repeated infection cycles (ICs) on green-pepper fruits, the aggressiveness (incidence [% of diseased fruits among 20 inoculated fruits] and severity [lesion length in mm] of infection) and fecundity (the average number of spores per five lesions) of the pathogen were measured in each cycle and compared between the ambient and twice-ambient treatments, and also between the early (ICs 31-50) and late (ICs 81-100) generations. In summary, the pathogen's aggressiveness and fecundity were significantly lower in the late generation. It is likely that aggressiveness and fecundity of C. acutatum may be reduced as global $CO_2$ and temperatures increase.

• 한국수산과학회지
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• 제36권6호
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• pp.625-631
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• 2003

The aim of the present study was to investigate the ecological relationship between female body size (=shell length) and fecundity in a Korean population of protandric hermaphrodite, Crepidula onyx Sowerby, using 6 reproductive variables (the number of capsules per brood, capsule size, the number of embryos per capsule, total number of embryos per brood, egg size, and larval size). The investigation was based on 32 females, 107 egg capsules, 263 eggs, and 250 veliger larvae sampled in January 2000, from Yangpo, the southeastern coast of Korea. All foregoing reproductive variables, except larval size, were significantly correlated with the female body size (p<0.001$\~0.01$). There was a significant increase both in the number of capsules per brood and the number of embryos per capsule with female body size (p<0.001). Consequently, the fecundity of the female C. onyx increased with female body size to over 14.65 mm (the minimum size of egg brooding in the present study). This investigation, therefore, provides additional evidence that female fecundity of protandric hermaphrodites is positively correlated with female body size.

• International Journal of Industrial Entomology and Biomaterials
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• 제7권2호
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• pp.117-125
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• 2003

To know the impact of female pupal weight corresponding to the male cocoon shell weight upon fecundity, hatchability and percentage of non-viable eggs, the experimental multivoltine breeds namely BL67 and 96A were categorised into low, medium and high batches according to the weight of female pupae and male cocoon shells and moths emerged from low, medium and high female pupae were allowed to mate withmoths emerged from low, medium and high male cocoon shells. Both the experimental breeds of BL67 and 96A revealed a fairl trend in fecundity for high batch ＞ medium batch ＞ low batch. When data were statistically analysed, a significant (p ＜ 0.05) and a highly significant (p ＜ 0.01) increase in fecundity was observed in the medium and high batches of BL67 during November - December, 2002 whereas highly significant (p ＜ 0.01) increase was observed in the high batches of 96A during November - December, 2002. Data revealed a highly significant (p ＜ 0.01) increase in fecundity in medium and high batches of both the breeds during January - February, 2003. More interestingly, a significant (p ＜ 0.05) reduction was noted in percentage of non-viable eggs in high batches of 96A during January - February, 2003. But no significant variation in hatchability was noticed due to the effect of differential female pupal weight and male cocoon shell weight.