KERAGAAN PERTUMBUHAN DAN WARNA IKAN WILD BETTA (Betta sp.) DENGAN REKAYASA INTENSITAS CAHAYA DAN WARNA LATAR

Penelitian ini dilakukan untuk menguji pengaruh kondisi lingkungan dengan intensitas cahaya dan warna latar yang berbeda terhadap pertumbuhan dan warna ikan cupang (Betta sp.). Biota uji diberi kombinasi perlakuan perbedaan kondisi cahaya dan warna latar, yaitu: (A-1) 100 lux dan latar putih; (A-2) 100 lux dan latar hitam; (A-3) 100 lux dan latar biru; (B-1) 800 lux dan latar putih; (B-2) 800 lux dan latar hitam; (B-3) 800 lux dan latar biru; (C-1) 1.500 lux dan latar putih; (C-2) 1.500 lux dan latar hitam; dan (C-3) 1.500 Lux dan latar biru. Setiap perlakuan diulang tiga kali. Ikan diberikan pakan berupa larva Chironomus sp. secara ad libitum. Penelitian dilakukan selama 84 hari. Hasil terbaik diperoleh pada perlakuan A-1 (intensitas 100 lux dan latar putih), dengan laju pertumbuhan spesifik panjang dan bobot masing-masing sebesar 0,48 ± 0,06%/hari dan 0,75 ± 0,22%/hari; sintasan sebesar 100%, serta persentase perubahan hue (H), saturation (S), dan brightness (B) berturut-turut adalah 21 ± 18, 6 ± 10, dan 6 ± 18.This research was conducted to determine the effect of rearing environment and light intensity with different background coloration to improve the color quality and growth of wild betta fish (Betta sp.). The fishs which were placed in the small tanks and treated with different light intensities and background coloration. The treatments combinations were: (A-1) 100 lux and white background, (A-2) 100 lux and black background, (A-3) 100 lux and blue background, (B-1) 800 lux and white background, (B-2) 800 lux and black background, (B-3) 800 lux and black background, (C-1) 1,500 lux and white background, (C-2) 1,500 lux and black background, and (C-3) 1,500 lux and blue background. Each treatment was repeated three times. The fish were fed onfrozen Chironomus larvae twice a day. The research was conducted for 84 days. The result showed that the combination of 100 lux and white background resulted the best growth rate (0.48 ± 0.06 cm/day in length and 0.75 ± 0.22%/day in weight) and survival rate of 100%. The best combination had the value of hue (21 ± 18), saturation (6 ± 10), and brightness (6 ± 18).

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Effects of light intensity and temperature on Cylindrospermopsis raciborskii (Cyanobacteria) with straight and coiled trichomes: growth rate and morphology

Brazilian Journal of Biology ◽

10.1590/s1519-69842012000200016 ◽

2012 ◽

Vol 72 (2) ◽

pp. 343-351 ◽

Cited By ~ 15

Author(s):

MC. Bittencourt-Oliveira ◽

B. Buch ◽

TC. Hereman ◽

JDT. Arruda-Neto ◽

AN. Moura ◽

...

Keyword(s):

Growth Rate ◽

Light Intensity ◽

Morphological Changes ◽

Population Control ◽

Distinct Species ◽

Cylindrospermopsis Raciborskii ◽

Climatic Chamber ◽

Light Intensities ◽

Different Temperatures ◽

Lower Temperature

Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju (Ordem Nostocales) is one of the most troublesome bloom-forming species in Brazil. Understanding the population dynamics of the different morphotypes of C. raciborskii (straight and coiled) could assist in the prediction of favourable conditions for the proliferation of this potentially toxin-producing species. The aim of the present study was to assess the effects of two different light intensities and temperatures on the growth rate and morphology of the trichomes of the straight and coiled morphotypes. For such, two non-toxin producing strains of C. raciborskii were used - one with a coiled trichome (ITEP31) and another with a straight trichome (ITEP28). The strains were cultured in BG-11 medium in a climatic chamber under controlled conditions. Two light intensities (30 and 90 µmol.m-2.s-1 ) were combined at temperatures of 21 and 31 °C and the growth rate and morphological changes were analysed. The morphotypes responded differently to the different temperatures and light intensities. Both strains exhibited faster growth velocities when submitted to higher light intensity and temperature. The lower temperature and higher luminosity hampered the development of both strains. Variations in cellular morphology and an absence of akinetes in both strains were related to the lower temperature (21 °C). The coiled morphotype demonstrated considerable phenotype plasticity, changing the morphology of trichome throughout its growth curve. Although molecular analysis does not sustain the separation of the morphotypes as distinct species, their different eco-physiological responses should be considered further knowledge of extreme importance for the population control of these potentially toxic organisms.

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Evaluation of larvae production and growth of juvenile red tilapia NIFI F1 during the nursery phase

Jurnal Iktiologi Indonesia ◽

10.32491/jii.v18i3.420 ◽

2019 ◽

Vol 18 (3) ◽

pp. 251

Author(s):

Adam Robisalmi ◽

Priadi Setyawan ◽

Bambang Gunadi

Keyword(s):

Growth Rate ◽

Survival Rate ◽

Specific Growth Rate ◽

Seed Production ◽

Specific Growth ◽

Stocking Density ◽

Brood Stock ◽

Female Ratio ◽

Red Tilapia ◽

Ad Libitum

Genetic quality improvement can be done through breeding programs. The indicator of success in the selection is the improvement of the character of production. Larval production and growth of NIFI of F1generation red tilapia seeds in the selection and its control parents were evaluated in this study. The research was conducted at the Fish Breeding Research Center for four months. Spawning was carried out on freshwater ponds of cage with size of 1 x 1 m. Tilapia brood stock were stocked with male to female ratio of 1: 1. The larvae rearing were conducted in the cage with size 2x2x1 m3 and stocking density 125 m-2. Pellets with a protein content of 38-40% are given to ad libitum larvae three times a day for first month, and then feeding rate was given 15-20% daily from biomass. Seed production, growth, specific growth rate, and survival rate were observed. The results of the experiment show a difference between fish selected and control. Seed production of selection reached 540 ± 114 and controls 508 ± 142. The growth performance of selected red tilapia juvenile showed higher compared with the control. The mean length of selected population reached 6.33 ± 0.43 cm , weight gain 6.60 ± 0.52 g, specific growth rate 7.33 ± 0% g days-1 and survival rate 81.50 ± 4.46% were respectively and the control population 5.76 ± 0.52 cm ; 4,90 ± 0.58 g; 4.50 ± 0.35% g days-1; and 74.85 ± 3.26%. These values indicate that the growth of red tilapia juvenile NIFI F1 generation was increased 25.76%.AbstrakSalah satu upaya yang dapat dilakukan untuk meningkatkan kualitas genetik yaitu melalui program pemuliaan. Per-baikan karakter reproduksi dan pertumbuhan dapat digunakan sebagai indikator keberhasilan seleksi. Penelitian ini bertujuan untuk mengevaluasi produksi larva dan pertumbuhan benih ikan nila merah NIFI F1 dari induk seleksi dan kontrol. Kegiatan dilaksanakan selama empat bulan di Balai Riset Pemuliaan Ikan. Pemijahan dilakukan di kolam air tawar pada hapa 1 m x1 m. Perbandingan induk ikan nila jantan dan betina 1:1. Larva yang sudah dipanen dimasukkan pada hapa pendederan ukuran 2x2x1 m3 dengan padat tebar 125 ekor m-2 . Selama pendederan , larva diberi pakan (protein 38-42%) secara ad libitum tiga kali sehari pada bulan pertama dan selanjutnya diberi pakan dua kali sehari 15-20% dari biomassa. Pakan yang diberikan selama pendederan mempunyai protein berkisar 38-42%. Parameter yang diamati meliputi produksi larva, pertumbuhan, laju pertumbuhan spesifik, dan sintasan. Hasil penelitian menunjukkan produksi larva ikan nila merah seleksi yaitu 540±114 ekor dan kontrol 508±142 ekor. Performa pertumbuhan benih ikan nila merah seleksi menunjukkan hasil yang lebih tinggi dibanding kontrol dengan nilai pertumbuhan panjang 6,33 ±0,43cm, pertumbuhan bobot 6,60±0,52 g, laju pertumbuhan spesifik 7,33±0% g hari-1 serta sintasan 81,50±4,46%, se-dangkan populasi kontrol masing-masing 5,76±0,52 cm; 4,90±0,58 g; 4,50±0,35% g hari-1; dan 74,85±3,26%. Nilai ini menunjukkan bahwa ada peningkatan pertumbuhan sebesar 25,76% pada benih ikan nila merah NIFI F1.

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FLUORESCENT LAMP LIGHT INTENSITY ON THE EMBRYOGENESIS DEVELOPMENT AND THE SURVIVAL OF PEARL OYSTER (Pinctada maxima) LARVAE

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.29244/jitkt.v5i2.7567 ◽

2013 ◽

Vol 5 (2) ◽

Author(s):

Mat Sardi Hamzah

Keyword(s):

Survival Rate ◽

Light Intensity ◽

Pearl Oyster ◽

Larval Rearing ◽

Fluorescent Lamp ◽

Brood Stock ◽

Dark Treatment ◽

Light Intensities ◽

Significant Difference ◽

Pinctada Maxima

One of the important factors in determining the success of pearl oyster (Pinctada maxima) culture is the quality and quantity of larvae produced in brood stock spawning process in the laboratory. Problems were often found in larval rearing and larvae attachment to the substrate that were low in quality and little number of larvae. The study purposes were observe the embryogenesis development and the survival rate of pearl oyster larvae under different fluorescent lamp light intensities. The study was conducted in August 1nd – 30th, 2011 in Sambelia Bumi Gemilang Hamparan Mutiara laboratory, East Lombok. Results revealed that different in light intensities effected the survivorship of the pearl oyster larvae significantly (p<0.01). Honest Significant Difference (HSD) test indicated that the highest survival rate occurred in dark condition (dark treatment) of 38%, followed by intensity of 10 watts (34.67%), 5 watts (30.67%) and 15 watts (4.66%) resfectively Keywords: embryogenesis development, survivorship, pearl oyster (Pinctada maxima) larvae, fluorescent lamp light intensity

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Effect of light and humus on survival and height growth of ash (Fraxinus excelsior L.) seedlings

Silva Gandavensis ◽

10.21825/sg.v63i0.834 ◽

1998 ◽

Vol 63 ◽

Cited By ~ 3

Author(s):

M. Tabari ◽

M. Lust ◽

J. Neirynck

Keyword(s):

Survival Rate ◽

Light Intensity ◽

Growing Season ◽

Height Growth ◽

Fraxinus Excelsior ◽

High Survival ◽

Light Intensities ◽

Stem Quality ◽

Humus Type ◽

Closed Canopy

In 1997, 300 3-month-old ash (Fraxinus excelsior L.) seedlings were removed out of the three different humus types (100 seedlings from each humus type) in the experimental forest of Aelmoeseneie (University of Ghent) with a closed canopy, in north of Belgium. Humus types were described as active mull with pH of 5.3-6.5, acid mull with pH of 4.4-5.2 and moder mull with pH of 3.8-4.3. Seedlings were transplanted in plastic pots, filled by the original soil, and placed under five levels of light intensity (2.5, 10, 18,28 and 92%), inside and outside the forest. Only with 92% light intensity seedlings were watered as necessary to avoid any appreciable water deficit. The results after 1 growing season revealed that seedlings attained a very high survival rate (95.3%). Survival was the highest when seedlings grew under semi-closed canopy (10, 18, and 28%) and also outside the forest at the 92% light intensity, compared with those under closed canopy (2.5%). It also confirmed that ash seedlings are shade tolerant, but with little growth. Height growth indicated an increasing growth response to nutrient availability with increasing light intensity. In fact, minimum height growth was observed in lower light intensities (2.5 and 10%) and the maximum value in higher light intensities (28 and 92%). Height growth of ash seedlings increased at humus types of active and acid mull, compared with moder mull. At the end of the first growing season, lack of differences in survival rate and height growth, produced under 18, 28 and 92% light intensity, revealed that training the seedlings under semiclosed canopy (18 and 26%) has a preference to those under relatively full daylight (92%) associated with watering. Therefore, the first year observations showed that ash seedlings, either in view of stem quality and growth or with regard to the facilities of maintenance, are preferable to be trained under intermediate light intensities (preferably 28%), at the high nutritional humus (active and acid mull).

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FLUORESCENT LAMP LIGHT INTENSITY ON THE EMBRYOGENESIS DEVELOPMENT AND THE SURVIVAL OF PEARL OYSTER (Pinctada maxima) LARVAE

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.28930/jitkt.v5i2.7567 ◽

2013 ◽

Vol 5 (2) ◽

Author(s):

Mat Sardi Hamzah

Keyword(s):

Survival Rate ◽

Light Intensity ◽

Pearl Oyster ◽

Larval Rearing ◽

Fluorescent Lamp ◽

Brood Stock ◽

Dark Treatment ◽

Light Intensities ◽

Significant Difference ◽

Pinctada Maxima

One of the important factors in determining the success of pearl oyster (Pinctada maxima) culture is the quality and quantity of larvae produced in brood stock spawning process in the laboratory. Problems were often found in larval rearing and larvae attachment to the substrate that were low in quality and little number of larvae. The study purposes were observe the embryogenesis development and the survival rate of pearl oyster larvae under different fluorescent lamp light intensities. The study was conducted in August 1nd – 30th, 2011 in Sambelia Bumi Gemilang Hamparan Mutiara laboratory, East Lombok. Results revealed that different in light intensities effected the survivorship of the pearl oyster larvae significantly (p<0.01). Honest Significant Difference (HSD) test indicated that the highest survival rate occurred in dark condition (dark treatment) of 38%, followed by intensity of 10 watts (34.67%), 5 watts (30.67%) and 15 watts (4.66%) resfectively Keywords: embryogenesis development, survivorship, pearl oyster (Pinctada maxima) larvae, fluorescent lamp light intensity

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Impact of increase in temperature and light intensity on development and metamorphosis of hatchery reared silver pompano Trachinotus blochii (Lacepede, 1801) larvae

Indian Journal of Fisheries ◽

10.21077/ijf.2018.65.2.37091-18 ◽

2018 ◽

Vol 65 ◽

Author(s):

R. Jayakumar ◽

M. Sakthivel ◽

A. K. Abdul Nazar ◽

G. Tamilmani ◽

P. Rameshkumar ◽

...

Keyword(s):

Growth Rate ◽

Light Intensity ◽

Water Temperature ◽

Light Stress ◽

Growth Reduction ◽

Light Intensities ◽

Different Temperatures ◽

The Impact ◽

Trachinotus Blochii

The impact of increase in temperature and light intensity on development and metamorphosis of hatchery produced larvae of silver pompano Trachinotus blochii (Lacepede, 1801) was studied. Two sets of larviculture tanks (Set 1 and Set 2) in triplicate were exposed to two different temperatures and varying light intensities. The growth of the larvae from day one to day 25 post-hatch (dph) and metamorphosis were studied. It was found that an increase of 2°C water temperature and increased light intensity significantly reduced the growth. The percentage of growth reduction gradually decreased and got stabilised towards the end of larviculture with a mean reduction of 15%. Further, a delay of three days in metamorphosis was also observed in Set 2. The reduced growth rate coupled with change in pigmentation of larvae can be considered as the resilience response of the larvae to combat temperature and light stress without compromising survival.

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Growth, biomass, and chlorophyll-a and carotenoid content of Nannochloropsis sp. strain BJ17 under different light intensities

Jurnal Akuakultur Indonesia ◽

10.19027/jai.16.1.15-21 ◽

2017 ◽

Vol 16 (1) ◽

pp. 15

Author(s):

Muhammad Fakhri ◽

Nasrullah Bai Arifin ◽

Anik Martina Hariati ◽

Ating Yuniarti

Keyword(s):

Growth Rate ◽

Light Intensity ◽

Chlorophyll A ◽

Specific Growth ◽

Cell Concentration ◽

Carotenoid Content ◽

Biomass Growth ◽

Live Feed ◽

Light Intensities ◽

Effect Of Light

ABSTRACT Nannochloropsis sp. has been identified as sources of live feed and pigment in aquaculture. To increase the production, the optimal environmental conditions for microalgae are required. Light intensity is one of the important factors that significantly affects the biomass and pigment of microalgae. The study aimed to determine the effect of light intensity (1,500; 3,000; and 4,500 lux) on growth, biomass production, chlorophyll-a, and carotenoid content of Nannochloropsis sp. strain BJ17. The results showed that different light intensities significantly affected the growth, biomass, chlorophyll-a and carotenoid contents of Nannochloropsis sp. strain BJ17. Increasing light intensity resulted in the increase of the growth rate, biomass, chlorophyll-a, and carotenoid contents of Nannochloropsis sp. strain BJ17. The cell achieved the highest specific growth rate of 1.729 %/day and the cell concentration of 43.333×106 cell/mL at a light intensity of 4,500 lux. The highest chlorophyll-a and carotenoid concentrations of algae were obtained at 4,500 lux (8.304 μg/mL and 3.892 μg/mL, respectively). This study suggested that increasing light intensity led to the increase in the growth, biomass, chlorophyll-a, and carotenoid content of Nannochloropsis sp. strain BJ17. Keywords: carotenoid, chlorophyll, biomass, growth rate, light intensity ABSTRAK Nannochloropsis sp. diketahui sebagai sumber pakan alami dan pigmen pada budidaya perikanan. Budidaya pada kondisi lingkungan yang optimal diperlukan untuk meningkatkan produksi mikroalga. Intensitas cahaya merupakan salah satu faktor esensial yang secara signifikan mempengaruhi biomassa dan pigmen mikroalga. Tujuan penelitian ini adalah untuk menentukan pengaruh intensitas cahaya yang berbeda (1.500, 3.000, and 4.500 lux) terhadap pertumbuhan, produksi biomassa, klorofil-a, dan karotenoid Nannochloropsis sp. strain BJ17. Hasil menunjukkan bahwa intensitas cahaya yang berbeda berpengaruh secara signifikan terhadap pertumbuhan, biomassa dan klorofil-a dan karotenoid Nannochloropsis sp. strain BJ17. Semakin tinggi intensitas cahaya maka laju pertumbuhan, biomassa, kandungan klorofil-a dan total karotenoid Nannochloropsis sp. strain BJ17 semakin tinggi. Laju pertumbuhan spesifik tertinggi 1,729%/hari dan konsentrasi sel maksimum tertinggi 43,333×106 sel/mL dihasilkan pada intensitas cahaya 4.500 lux. Konsentrasi klorofil-a (8,304 μg/mL) dan karotenoid (3,892 μg/mL) tertinggi juga diperoleh pada intensitas cahaya 4.500 lux. Studi ini menunjukkan bahwa peningkatan intensitas cahaya berperan dalam meningkatkan pertumbuhan, produksi biomassa, klorofil-a, dan karotenoid Nannochloropsis sp. strain BJ17. Kata kunci: karotenoid, klorofil, biomassa, pertumbuhan, intensitas cahaya

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PENINGKATAN PERTUMBUHAN DAN SINTASAN BENIH IKAN TUNA SIRIP KUNING, Thunnus albacares DALAM PENDEDERAN SISTEM INDOOR

Jurnal Riset Akuakultur ◽

10.15578/jra.16.1.2021.9-17 ◽

2021 ◽

Vol 16 (1) ◽

pp. 9

Author(s):

Jhon Harianto Hutapea ◽

Ananto Setiadi ◽

Gunawan Gunawan

Keyword(s):

Growth Rate ◽

Survival Rate ◽

Light Intensity ◽

Sea Water ◽

Feeding Habits ◽

Yellowfin Tuna ◽

Total Length ◽

Reinforced Plastic ◽

Minced Fish ◽

Fish Tank

Sintasan larva hingga benih ikan tuna sirip kuning di hatchery sudah meningkat dari 0,05% menjadi 0,20%-0,50%. Namun mortalitas pada pemeliharaan tahap berikutnya sangat tinggi. Kematian benih karena menabrak dinding bak/jaring, berkaitan dengan kebiasaan renang dan kondisi lingkungan. Oleh karena itu, riset pendederan ini difokuskan pada pengamatan kebiasaan berenang dan pemangsaan, serta kondisi lingkungan. Wadah yang digunakan adalah enam buah bak fiberglass reinforced plastic (FRP) diameter 2,7 m; ketinggian 1,0 m; dan diisi dengan air laut 5 m3. Hewan uji berupa benih ikan tuna sirip kuning dengan panjang total 29,82 ± 2,51 mm hasil produksi dari hatchery, sebanyak 50 ekor benih per bak. Perlakuan dalam riset adalah perbedaan sistem pemeliharaan, yaitu: (A) indoor dan (B) outdoor dengan tiga ulangan dan lama penelitian 21 hari. Pakan yang digunakan adalah ikan segar berupa benih bandeng yang dimatikan dan ikan teri dengan panjang total 15-25 mm dan ikan cincang (minced fish). Frekuensi pemberian pakan adalah enam kali per hari dan diberikan secara satiasi. Parameter meliputi suhu, oksigen terlarut, dan intensitas cahaya diukur setiap hari. Hasil riset menunjukkan bahwa sintasan dalam pendederan sistem indoor sebesar 20,0 ± 4,0% lebih tinggi (P<0,05) dibanding dengan sistem outdoor (6,7 ± 5,0%). Pertumbuhan bobot spesifik 12,4% hari-1 pada sistem indoor lebih baik dibandingkan sistem outdoor yang hanya 9,8% hari-1 (P<0,05). Dari hasil penelitian ini dapat disimpulkan bahwa intensitas cahaya dan suhu yang lebih stabil pada pendederan sistem indoor memberikan sintasan dan pertumbuhan yang lebih baik dibandingkan pada sistem outdoor. Namun demikian, disarankan bahwa pendederan dalam bak FRP sebaiknya tidak lebih dari dua minggu agar diperoleh sintasan yang lebih tinggi dan selanjutnya dipindahkan ke karamba jaring apung (KJA).The survival rate of reared yellowfin tuna from larvae to juvenile stages in hatchery has been improved from 0.05% to 0.20%-0.50%. Unfortunately, the fish’s mortality rate during the nursery phase is still very high. Unpredicted swimming and feeding behaviors have resulted the reared juveniles to uncontrollably hit the tank wall and died. Therefore, this research was carried out to study the swimming and feeding habits of yellowfin tuna juveniles and its response to different rearing environments. Six fiberglass reinforced plastic (FRP) tanks with a diameter of 2.7 m, height 1.0 m, and filled with 5 m3 of filtered sea water were used in the study. Yellowfin tuna juveniles with an average total length of 29.82 ± 2.51 mm were harvested from a hatchery and placed into each tank at a density of 50 fish tank-1. The treatments applied were two nursery systems: (A) indoor and (B) outdoor system with three replicates. The rearing treatment lasted for 21 days. Raw fish was given as feed consisting of mixed of defrosted milkfish fry and small anchovy with total length ranged between 15-25 mm as well as minced fish meat. Feed was given six times per day at satiation. The observed parameters were temperature, dissolved oxygen, and light intensity measured daily. The results showed that the survival rate of juvenile in the indoor system was 20.0 ± 4.0%, which was higher (P<0.05) than that of the outdoor system (6.7 ± 5.0%). Weight specific growth rate of fish reared in the indoor system was 12.4% day-1 which was better than that of the outdoor system which was only 9.8% day-1 (P<0.05). This research concludes that a stable light intensity and water temperature in the indoor nursery system gives better survival and growth rate on yellowfin tuna juvenile. Nevertheless, this research recommends that the nursery phase of yellowfin tuna juvenile in FRP tank should be carried out not more than two weeks in order to produce a higher survival rate and then transferred to floating net cages.

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Growth, biomass and lipid productivity of a newly isolated tropical marine diatom, Skeletonema sp. UHO29, under different light intensities

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d210430 ◽

2020 ◽

Vol 21 (4) ◽

Cited By ~ 1

Author(s):

Indrayani Indrayani ◽

Haslianti Haslianti ◽

Asmariani Asmariani ◽

Wellem Muskita ◽

Abdul Muis Balubi

Keyword(s):

Growth Rate ◽

Light Intensity ◽

High Growth ◽

Biomass Productivity ◽

Dry Weight ◽

High Light Intensity ◽

High Growth Rate ◽

Lipid Productivity ◽

Marine Diatom ◽

Light Intensities

Abstract. Indrayani I, Haslianti H, Asmariani A, Muskita WH, Balubi M. 2020. Growth, biomass and lipid productivity of a newly isolated tropical marine diatom, Skeletonema sp. UHO29, under different light intensities. Biodiversitas 21: 1498-1503. Light is one of the important factors affecting growth and biochemical composition of microalgae. The aim of this study was to determine growth, biomass and lipid productivity of a newly isolated marine diatom, Skeletonema sp.UHO29 under different light intensities. The Skeletonema sp. was cultured in 300 mL conical flasks containing 150 mL of f/2 medium under three different light intensities (28, 60 and 110 μmol photons m-2 s-1 ) with three replications. The cultures were incubated under ambient room temperatures, and a cycle of 12 hours light and 12 hours dark, in batch modes for two weeks. The results showed that the highest specific growth rate (0.56 d-1) was achieved at the highest light intensity (110 μmol photons m-2 s-1) and the lowest (0.11 d-1) was obtained at the lowest light intensity (28 μmol photons m-2 s-1). The highest biomass yield (0.62 g L-1) and biomass productivity (0.34 g L-1 d-1) was achieved at the highest light intensity. However, the highest lipid yield (0.175 g L-1), lipid content (28.78% ash-free dry weight) and lipid productivity (0.067 g L-1 d-1) were achieved at medium light intensity. The alga prefers high light intensity for higher growth rate and biomass productivity but it produces more lipids at medium light intensity. This study indicated that the Skeletonema sp.UHO29 is a potential species for outdoor mass cultivation and is a promising microalgal strain for use as a biodiesel feedstock due to its high growth rate, high biomass and lipid productivity.

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The Effect of Feeding System on the Carcass Quality of Crossbred Lambs with Texel

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis ◽

10.11118/actaun202068010017 ◽

2020 ◽

Vol 68 (1) ◽

pp. 17-24

Author(s):

Angela Cividini ◽

Dušan Terčič ◽

Mojca Simčič

Keyword(s):

Growth Rate ◽

Meat Quality ◽

Carcass Quality ◽

Quality Traits ◽

Feeding System ◽

Ad Libitum ◽

Daily Gain ◽

Effect Of Feeding ◽

Carcass Cuts

The aim of this study was to estimate the effect of feeding system on the growth rate and carcass quality of crossbred Improved Jezersko-Solčava x Texel (JSRT) lambs and to evaluate the effect of sex on these traits. The trial was conducted in nature according to the traditional rearing systems. The trial included 44 crossbred lambs, which were born and reared until the slaughter in three different flocks. In the age of 10 days suckled lambs were offered with ad libitum corresponding diets according to the feeding system. All lambs were slaughtered in seven consecutive days by the same procedure. The effect of feeding system significantly affected daily gain from birth to slaughter, EUROP carcass conformation and shoulder width. Likewise, the effect of sex significantly affected daily gain from birth to slaughter and internal fatness of carcasses. According to carcass cuts the feeding system significantly affected only the proportion of neck and leg. Considering meat quality traits, feeding system had a significant effect on the pH 45 and CIE a* values. In this study, we could speculate that more than the feeding system the growth and the carcass traits as well as meat traits were affected by the amount of the supplement.

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