Length-weight relationships and reproductive biology of commercially important fishes from Ribb Reservoir, Ethiopia

Agumassie Tesfahun Asres,Sale Alebachew,Negesse Kebtieneh The Korean Society of Fisheries and Aquatic Scienc 2023 Fisheries and Aquatic Sciences Vol.26 No.5

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.

Some aspects of the reproductive biology of Synodontis schall from a lotic freshwater in Nigeria

Ukpamufo Cyril Olowo,Nkonyeasua Kingsley Egun,Ijeoma Patience Oboh 한국수산과학회 2023 Fisheries and Aquatic Sciences Vol.26 No.4

The suitability of any fish species for successful aquaculture requires basic information on its reproduction and growth. This study investigated some facets of the reproductive biology of Synodontis shall (Mochokidae) from River Siluko in Nigeria. Fish samples were collected forth-nightly for a duration of fourteen (14) months—March 2015 to April, 2016 with the assistance of artisanal fishermen. Fishes were identified using taxonomic guides and standard techniques were used for determination of sex ratio, gonad maturation and fecundity. Linear regression method was used to define the correlation between fecundity and fish length, body weight and ovary weight. Results showed that sex ratio did not indicate a significant divergence (p > 0.05) from the 1 male to 1 female distribution ratio (1:1.41). Gonad morphology revealed paired gonads. Testes and ovaries were classified into four maturity stages: immature, resting, ripening and ripe. Gonadosomatic index ranged from 0.04 to 5.68 (males) and 0.03 to 20.19 (females). Absolute fecundity ranged from 1,014 to 4,520 eggs (mean = 2,592 eggs) and did not correlate significantly (p > 0.05) to ovary weight. This study has contributed to existing data on the biology of freshwater fish species in Nigeria and provided valuable information for fishery management tools in the conservation and utilization of this valuable freshwater fish species.

Effect of Mating Duration and Multiple Use of Male Moth on Reproductive Performance of Some Cross Breeds of Silkworm, Bombyx mori L.

( Kunal Sarkar ),( Manmatha Mandal ),( Shanmugam Manthira Moorthy ) 한국잠사학회 2009 International Journal of Industrial Entomology Vol.19 No.2

The effect of mating duration and multiple use of male on fecundity and fertility was investigated in the hybrids of Silkworm, Bombyx mori L. One hour to five hours of mating duration did not affect egg laying (fecundity) significantly, while fertilization affected significantly. Below 50% fertility was noticed when mating duration was reduced to below two hours. Similarly multiple use of male caused significant reduction in fertility but not fecundity. Till fourth mating no significant reduction in fertility was observed, thereafter fertility reduced considerably.

Effect of Mating Duration and Multiple Use of Male Moth on Reproductive Performance of Some Cross Breeds of Silkworm, Bombyx mori L.

Sarkar, Kunal,Mandal, Manmatha,Moorthy, Shanmugam Manthira Korean Society of Sericultural Science 2009 International Journal of Industrial Entomology Vol.19 No.2

The effect of mating duration and multiple use of male on fecundity and fertility was investigated in the hybrids of Silkworm, Bombyx mori L. One hour to five hours of mating duration did not affect egg laying (fecundity) significantly, while fertilization affected significantly. Below 50% fertility was noticed when mating duration was reduced to below two hours. Similarly multiple use of male caused significant reduction in fertility but not fecundity. Till fourth mating no significant reduction in fertility was observed, thereafter fertility reduced considerably.

Influence of host plants on the development, survivorship, and fecundity of the summer fruit tortrix moth, Adoxophyes orana (Lepidoptera: Tortricidae)

Li Guang‐wei,Wang Hui‐min,Yang Wen‐tao,Chen Xiu‐lin,Li Bo‐liao,Chen Yu‐xin 한국곤충학회 2021 Entomological Research Vol.51 No.10

The summer fruit tortrix moth Adoxophyes orana is a seriously damaged leaf roller pest for fruit trees. In this study, we evaluated the effect of five host plants (apple, Malus domestica B.; peach, Prunus persica var. nectarina; apricot, Armeniaca vulgaris Lam.; mulberry, Morus alba L.; and jujube, Ziziphus jujuba M.) on the development, survival, and fecundity of A. orana under laboratory conditions. Results showed that the development times of A. orana on jujube were significantly longer than those on the other four plants. The preimaginal survival rate was influenced by the host plants, which were fed during the larval stage, and with the highest on peach, followed by apple, apricot, and mulberry, and with the lowest on jujube. Adult females from larvae reared on apricot laid the greatest numbers of eggs (318.11 eggs per female), while that on apple, jujube, and mulberry was smaller, and no significant difference was observed among them. The highest intrinsic rate of increase (rm) was observed on peach and apricot; these two fruit trees were considered to be the most suitable host plant for A. orana because of the shorter developmental duration, higher survival rate, and the highest fecundity.

Fitness consequences of body melanization in Drosophila immigrans from montane habitats

Shama Singh,Seema RAMNIWAS,Ravi PARKASH 한국곤충학회 2009 Entomological Research Vol.39 No.3

We investigated eight populations of Drosophila immigrans from low to high montane localities (600–2202 m) for altitudinal variations in abdominal melanization and fitness-related traits (desiccation resistance, copulation duration, and fecundity). On the basis of common garden experiments, persistence between-population differences at 21°C suggests that observed variations in fitness-related traits have a genetic basis. Parent–offspring regression analyses showed higher heritability (h2= 0.77) for melanization patterns on all the abdominal tergites. All the traits showed significantly higher repeatability across generations. Under colder and drier environments in dispersed montane localities, abdominal melanization and desiccation resistance significantly increased (1.5–1.9 fold) along altitude. Thus, there are correlated effects of abdominal melanization on desiccation resistance. Genetic correlations, based on family means, were significantly high between abdominal melanization and other fitness traits. Furthermore, darker flies along increasing altitude resulted in a 35–40% increase in copulation duration as well as fecundity. There are significantly positive correlations of abdominal melanization with copulation duration as well as fecundity on the basis of within- as well as between-population variations. Such observations are in agreement with the thermal budget hypothesis. Present data suggest that changes in body melanization impact fitness-related traits in montane populations of Drosophila immigrans.

Assessing egg deposition behaviour of female black soldier fly (Hermetia: Illucens) in Kumasi, Ghana using MOSW as bait

Addo Priscilla,Fosu-Gyasi Samuel,Oduro-Kwarteng Sampson,Duku Godwin Armstrong,Awuah Esi 한국응용곤충학회 2024 Journal of Asia-Pacific Entomology Vol.27 No.1

The availability of the black soldier fly (BSF) at a location is of great importance if its larvae are to be used for commercial composting of municipal organic solid waste (MOSW). In this context, it is crucial to determine where the insects are readily available and how natural environmental conditions influence their oviposition. This study used MOSW as bait to determine locations where these insects are readily available and their egg cluster as an indication of their presence. Data were collected at four locations: Plantain farm, poultry farm, under a pear tree, and waste communal container site. For each site, data were collected in the morning (6:00 a. m.–12:00 p.m.), afternoon (12:00 p.m.–6:00 p.m.), and evening (after 6:00 p.m.) to determine the peak egglaying times of these insects. This was carried out for two seasons of the year – rainy season (June, July and August) and dry season (December, January, and February) to assess seasonal variability on oviposition and fecundity. Environmental conditions such as temperature, relative humidity, and light intensity were also measured under which oviposition took place. The highest average number of BSF egg clusters of 17.5 ± 13.74 was harvested at the waste communal container site and the lowest average number of 2 ± 0.81 was harvested at the poultry farm. Peak egg laying times were recorded in the afternoon between 12:00 p.m. and 6:00 p.m., where an average of 15.17 ± 4.7 clusters were harvested. Most BSF egg clusters were harvested during the rainy season, averaging 9.1 ± 12.2. The dry season recorded a higher average number of eggs per cluster at 454.18 ± 164.92. It is concluded that BSF larval composting technology can be commercialized in Kumasi, Ghana as the insects were readily available during the two main seasons in the country.

Response of Spodoptera frugiperda (Lepidoptera: Noctuidae) to salt‐stressed maize plants

Wang Zai‐Ling,Haseeb Muhammad,Zhang Run‐Zhi 한국곤충학회 2021 Entomological Research Vol.51 No.11

Salt-stressed maize is an economically important crop in many arid and semi-arid regions of the world where soil salinization is most common, and the invasive fall armyworm (FAW) Spodoptera frugiperda threatens global maize production. It thus poses a puzzle of whether FAW populations feeding on salt-stressed maize plants are becoming more or less invasive. Here, we evaluated the FAW response to salt-stressed maize plants by examining effects of salt-stressed maize plants on FAW survival, development and fecundity. We found a longer larval development time (salt-stressed, 12.9 ± 0.8 d; non-stressed, 11.3 ± 0.4 d), but unaffected survival rate and pupal mass accumulation in FAW feeding on salt-stressed maize plants. Moreover, the lifetime egg production of FAW females feeding on salt-stressed maize plants (633.5 ± 62.7 eggs) was reduced by nearly half compared with those feeding on non-stressed maize plants (1255.9 ± 70.3 eggs). Overall, FAW showed a negative response to salt-stressed maize plants. Due to limited population increase potential, FAW populations feeding on salt-stressed maize plants should pose less of a problem than ones feeding on non-stressed maize plants do. In practice, salt-stressed maize plants are quite common in arid and semi-arid regions where the relatively high-salinity groundwater is often used to irrigate maize plants, potentially limiting FAW population size. Thus, salt-stressed maize plants would contribute to practical applications of integrated pest management (IPM) strategies in controlling FAW.

Effect of Cold Storage on quality of Geocoris pallidipennis and Micromus angulatus

Meeja Seo,Jeong Hwan Kim,Bo Yoon Seo,Kwang Ho Kim,Gwan Seok Lee,Chang Woo Ji,Ji Eun Kim,Jum Rae Cho 한국응용곤충학회 2019 한국응용곤충학회 학술대회논문집 Vol.2019 No.04

It was available to store both nymphs and adults of Geocoris pallidipennis at 5℃ for 3 weeks without negative effects on their survival, fecundity, and Bamisia tabaci nymph predation. Up to 140 days, it was also possible to store Micromus angulatus adults at low temperature, showing approximately 50% cumulative survival rate, but over 2 week cold storage was not suitable for their fecundity. With the increase of cold storage duration, the aphid predation by M. angulatus decreased, but it could be possible to cold store until 5 weeks without a significant effect on their aphid predation. Thus, short term cold storage of G. pallidipennis and M. angulatus could be useful for inundative biological control.

옥녀봉의 지형경관 특성과 장소성

강송아,박철웅 한국지명학회 2014 지명학 Vol.20 No.-

The name of place does not simply mean the geographical name of a certain place, but implies the conceptual system for the meaning of place. This research aims to explain the characteristics of geomorphological landscape through the name of Okneyobong and the placeness on the geographical place's name of Okneyobong. The Okneyobong is symbolized as the meaning of place through the mixture of specific terrains and the figure of Okneyo. The geomorphological characteristics of Okneyo are linguistically systemized as the meaning of Okneyo represents 'abundance and fecundity'. However, as modern economic base, family relations and social attitude have been changed, the symbolic meaning of Okneyo weakens, following the demise of placeness. The fetishism for Okneyo regarded as hedonism and superstition. Thus this research is worthful because this provide a new way to consider the geographical name as text to understand spatial conception. 지명은 단순히 지역의 명칭을 의미하는 것이 아니라 장소의 의미에 대한 인식체계로, 지명에는 주민들의 역사와 문화가 담겨있다. 본 연구는 옥녀봉이란 지명을 통해 지형경관적 특성과 지명의 장소성을 살펴보고자 한다. 옥녀봉은 특정한 산세와 옥녀라는 인물이 융합된 것으로 자연지리적 실제를 장소적 의미로 기호화한 것이다. 옥녀봉의 지형적 특성은 마을 구성원의 환경인식과 지속적인 관계를 맺으면서 옥녀는 ‘풍요와 다산’을 의미하는 언어적 표현으로 구체화되었다. 하지만, 현대사회의 경제적 토대, 가족관계 및 사회적 가치관이 변화하면서 옥녀가 지닌 상징성은 약화되고, 결과적으로 장소성의 소멸로 이어졌다. 옥녀에 대한 숭배는 미신과 쾌락적 이미지로 격하되었다. 본 연구는 지명을 공간인식의 텍스트로서 새롭게 조명한다는 점에서 연구의 가치가 있다고 판단된다.