Juliana Tomomi Kojima

@universidadeniltonlins.com.br

Vice-reitoria para Projetos de Pós-Graduação, Pesquisa e Inovação
Universidade Nilton Lins

Juliana Tomomi Kojima


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https://researchid.co/julianakojima

RESEARCH, TEACHING, or OTHER INTERESTS

Agricultural and Biological Sciences, Animal Science and Zoology, Aquatic Science
13

Scopus Publications

Scopus Publications

  • Influence of fasting and refeeding cycles on growth, health and feeding costs of the Amazonian fish Colossoma macropomum
    Ádria Silva GOMES, Samantha CHUNG, Renata Franco dos SANTOS, Rodrigo Yukihiro GIMBO, Juliana Tomomi KOJIMA, Lucas Pedro GONÇALVES JUNIOR
    Acta Amazonica, 2025
    Feed restriction can be used as a management strategy to increase feed efficiency through compensatory growth (a higher growth rate after a period of restricted feeding). However, there is still a lack of information on the physiological mechanisms underlying the fish responses to feed restriction. Therefore, this study aimed at investigating the cycles of fasting and refeeding on the performance, cost feeding, health and physiological mechanisms of juvenile tambaqui (Colossoma macropomum). For this purpose, feeding protocols were tested for 60 days: continuous feeding (control); two days of fasting and refeeding for two days (F2R2); two days of fasting and refeeding for three days (F2R3) and two days of fasting and refeeding for four days (F2R4), on a total of 108 two-month-old tambaqui juveniles (29.53 ± 1.31 g), distributed in 300 L boxes. Weight gain (g) was lower for the F2R2 and F2R3 treatments compared to the control. Fish subjected to the F2R4 feeding strategy showed similar growth to the group of fish continuously fed. Only the restriction protocol F2R3 resulted in a reduction in blood glucose, while cholesterol was reduced in F2R2 and F2R3. There was mobilization of hepatic glycogen in the F2R3 and F2R4 treatments, while muscle lipids were not altered. The different fasting cycles did not affect leukocyte respiratory activity, hematocrit or hemoglobin. The lowest relative feed cost values were in the F2R2 and F2R4 treatments. The F2R4 protocol reduces feed cost and maintains the ability to adjust energy metabolism without causing stress in C. macropomum.
  • Food restriction in larviculture of Colossoma macropomum (Cuvier, 1818) reared in varying salinities
    Arminda Alexandre BANGO, Lucas Pedro GONÇALVES JUNIOR, Thiago Mendes de FREITAS, Iracimar Batista do CARMO, Lorena Ianka Pontes da SILVA, Ana Carolina Nogueira MOURA, Juliana Tomomi KOJIMA
    Acta Amazonica, 2025
    Given the growing demand for tambaqui (Colossoma macropomum), economically sustainable protocols that guarantee quality in the larval stage are highly needed. Larviculture in low salinity environment can be used to reduce the daily rate of feeding, thus reducing costs. Food restriction can cause a decrease in fish growth, but it does not impair their capacity to grow if adequate feeding conditions are reestablished and if restriction is not held for too long. This study aimed at evaluating the effects of live food restriction on the growth performance and muscle morphometry of tambaqui larvae reared in different salinities. The 9,600 larvae were distributed in sixteen 60 L tanks, in a 2x2 factorial design, with two treatments, 0 and 2 g L-1 salinity (S0, S2) with food restriction of 50% (FR 50%) and without food restriction (FR 0%) of Artemia nauplii. After 15 days, no interactions were observed between the factors evaluated for production performance and muscle fibers of classes 10, 30, 40 and 50. However, the analysis of isolated factors demonstrated that the lower feeding rate reduced the performance of the larvae, while water salinity positively influenced performance and survival variables, and increased muscle fiber hyperplasia of class 20 in larvae submitted to food restriction. We conclude that live food deprivation of up to 50 % for tambaqui larvae reduces performance rates without compromising survival. To maintain growth performance and development of skeletal muscle, saline water (2g.L-1) can be applied for tambaqui larviculture in situations of live food scarcity.
  • Fish Viscera Silage: Production, Characterization, and Digestibility of Nutrients and Energy for Tambaqui Juveniles
    Thiago Macedo Santana, Francisco de Matos Dantas, Driely Kathriny Monteiro Dos Santos, Juliana Tomomi Kojima, Yugo Moraes Pastrana, Rogério Souza De Jesus, Ligia Uribe Gonçalves
    Fishes, 2023
    Fish viscera can be an important source of protein and energy for aquafeed, and its use contributes to circular aquaculture. The aim of this study was to produce acid and fermented silage from fish viscera to determine their nutritional value and the apparent digestibility coefficient of nutrients and energy for juvenile tambaqui (Colossoma macropomum). An acid silage and three fermented silages with different sources of carbohydrates (molasses, wheat bran, and cassava waste) were produced with 0.25% sorbic acid as an antifungal in the formulation. Silages presented an average of 55% dry matter, 62.9% lipids, and 12% crude protein. Leucine and lysine predominated as essential amino acids in the acid silage and fermented silages. Fish viscera silages presented EPA and DHA content from 5.4 to 17.8 and 1.7 to 8.9 mg.g−1 of lipids, respectively. The apparent digestibility coefficient (ADC) (indirect method) was above 82% for gross energy for all the formulations. The ADCs for protein were similar for the fermented silages, with a maximum 92% level for the fermented wheat bran silage. The bioconversion of fish viscera into silage makes it an energy ingredient for aquafeed that is well digested by tambaqui juveniles.
  • Pirarucu larviculture in green water provides heavier fish and modulates locomotor activity
    Francisco de Matos DANTAS, Thiago Macedo SANTANA, Juliana Tomomi KOJIMA, Flávio Augusto Leão da FONSECA, Ana Caroliny Cerdeira LOPES, Thaís Billalba CARVALHO, Ligia Uribe GONÇALVES
    Acta Amazonica, 2022
    The green water technique uses microalgae in the water of indoor larviculture, providing a darker environment to favor fish growth, welfare and health. We evaluated growth performance and locomotor activity after light exposure of pirarucu (Arapaima gigas) larvae reared in green or clear water. During one test, pirarucu larvae (3.6 ± 0.3 cm; 0.36 ± 0.1 g) were reared in 50-L circular tanks (n = 3 per treatment, 50 larvae per tank) in a static system containing green water [microalgae (w3algae; Bernaqua® 10 g m-3) added] or clear water (control). Fish weaning was achieved by co-feeding with Artemia nauplii and microdiets for seven days until full microdiet substitution. Larvae were biometrically evaluated on days 10, 17 and 24 to assess growth performance. In a second test, the locomotor activity of the larvae was analyzed before and after light exposure (1400 ± 60 lx) for 48 h according to an ethogram. After 24 days, the larvae reared in the green water were significantly heavier than those from the clear water, and displayed significantly fewer circular swimming movements. Body cortisol increased in both groups after light exposure. The microalgae provided an additional food source for larvae, with positive impact on growth until day 17 of larviculture. Green water can be a strategy to achieve better results in pirarucu larviculture, especially during and up to 10 days after the co-feeding period.
  • Farming tambaqui (Colossoma macropomum) in static clear water versus a biofloc system with or without Bacillus subtilis supplementation
    Driely Kathriny Monteiro dos Santos, Juliana Tomomi Kojima, Thiago Macedo Santana, Diogo Pereira de Castro, Paula Taquita Serra, Naiara Silva Menezes Dantas, Flávio Augusto Leão da Fonseca, Luís André Morais Mariúba, Ligia Uribe Gonçalves
    Aquaculture International, 2021
  • Stocking density for arapaima larviculture
    Thiago Macedo Santana, Amanda Halum Elias, Flávio Augusto Leão da Fonseca, Odair Rodrigues Freitas, Juliana Tomomi Kojima, Ligia Uribe Gonçalves
    Aquaculture, 2020
  • Predicted 2100 climate scenarios affects growth and skeletal development of tambaqui (Colossoma macropomum) larvae
    Ivã Guidini Lopes, Thyssia Bomfim Araújo‐Dairiki, Juliana Tomomi Kojima, Adalberto Luis Val, Maria Célia Portella
    Ecology and Evolution, 2018
    Climate changes driven by greenhouse gas emissions have been occurring in an accelerated degree, affecting environmental dynamics and living beings. Among all affected biomes, the Amazon is particularly subjected to adverse impacts, such as temperature rises and water acidification. This study aimed to evaluate the impacts of predicted climate change on initial growth and development of an important Amazonian food fish, the tambaqui. We analyzed growth performance, and monitored the initial osteogenic process and the emergence of skeletal anomalies, when larvae were exposed to three climate change scenarios: mild (B1, increase of 1.8°C, 200 ppm of CO2); moderate (A1B, 2.8°C, 400 ppm of CO2); and drastic (A2, 3.4°C, 850 ppm of CO2), in addition to a control room that simulated the current climatic conditions of a pristine tropical forest. The exposure to climate change scenarios (B1, A1B, and A2) resulted in low survival, especially for the animals exposed to A2, (24.7 ± 1.0%). Zootechnical performance under the B1 and A1B scenarios was higher when compared to current and A2, except for condition factor, which was higher in current (2.64 ± 0.09) and A1B (2.41 ± 0.14) scenarios. However, skeletal analysis revealed higher incidences of abnormalities in larvae exposed to A1B (34.82%) and A2 (39.91%) scenarios when compared to current (15.38%). Furthermore, the bone‐staining process revealed that after 16 days posthatch (7.8 ± 0.01 mm total length), skeletal structures were still cartilaginous, showing no mineralization in all scenarios. We concluded that tambaqui larvae are well‐adapted to high temperatures and may survive mild climate change. However, facing more severe climate conditions, its initial development may be compromised, resulting in high mortality rates and increased incidence of skeletal anomalies, giving evidence that global climate change will hamper tambaqui larvae growth and skeletal ontogeny.
  • Depletion of stored nutrients during fasting in Nile tilapia (Oreochromis niloticus) juveniles
    Caroline Nebo, Rodrigo Yukihiro Gimbo, Juliana Tomomi Kojima, Ken Overturf, Maeli Dal-Pai-Silva, Maria Célia Portella
    Journal of Applied Aquaculture, 2018
    We evaluated growth performance and metabolic responses in Nile tilapia (Oreochromic niloticus) juveniles (30.2 ± 0.9 g) subjected to 1 (F1), 2 (F2), or 3 weeks (F3) of fasting and then refed for 10 weeks (10WR) compared to controls (FC), which were fed for the full 13-week trial. Weight gain and specific growth rate (SGR) during fasting were lower in all treatments compared to the FC. However, during refeeding, feed intake/body mass and SGR increased in F1, F2, and F3, inducing partial compensatory growth. The hepatosomatic index (HSI), visceral fat index (VFI), liver glycogen (LG), and carcass lipid levels dropped in all fasted fish compared to FC (P < 0.05), showing a depletion of stored nutrients such as fat and LG. Along with LG, fat reserves were mobilized during fasting to maintain basal metabolism and survival, but these energy constituents returned to control levels at 10WR, at which time HSI was higher in all refed fish compared to FC. Additionally, the variables VFI, LG, and lipid in carcass increased in all refed fish, equaling those of FC at 10WR. The results showed that, in contrast with other protocols that used smaller tilapia juveniles, the feeding strategies utilized for Nile tilapia juveniles in this study (1 to 3 weeks of fasting and 10WR) were able to induce only partial compensatory growth. It can be concluded that in situations that require complete food restriction in juvenile Nile tilapia (30 g), an acceptable strategy is to limit the period of fasting to 1 week or less to minimize losses and to achieve partial compensatory growth.
  • Short periods of food restriction do not affect growth, survival or muscle development on pacu larvae
    J.T. Kojima, N.J. Leitão, O.C.C. Menossi, T.M. Freitas, M. Dal-Pai Silva, M.C. Portella
    Aquaculture, 2015
  • Larval development of indigenous South American freshwater fish species, with particular reference to pacu (Piaractus mesopotamicus): A review
    M.C. Portella, R.K. Jomori, N.J. Leitão, O.C.C. Menossi, T.M. Freitas, J.T. Kojima, T.S. Lopes, J.A. Clavijo-Ayala, D.J. Carneiro
    Aquaculture, 2014
  • Review on the ontogeny of larvae from neotropical freshwater fishes: the pacu model.
    Communications in Agricultural and Applied Biological Sciences, 2013
  • Influence of stock density in productive performance of freshwater angelfish (Pterophyllum scalare)
    Boletim do Instituto De Pesca, 2010
  • Feeding strategies with cycles of restriction and refeeding on growth performance of Nile tilapia juveniles, GIFT line
    Ciencia Rural, 2010