scholarly journals CICLO CIRCADIANO NO DESEMPENHO DE JUVENIS DE TILÁPIA-DO-NILO, SUBMENTIDOS A DIFERENTES MANEJOS ALIMENTARES

2021 ◽  
Vol 23 (1) ◽  
pp. 201-217
Author(s):  
Marcos César Nouals ◽  
Bruno Corrêa da Silva ◽  
Haluko Massago ◽  
Morgana Silva ◽  
Larissa Stockhausen ◽  
...  

Este estudo avaliou o desempenho zootécnico, retenção de nutrientes e índices corporais em tilápias-do-nilo (Oreochromis niloticus), submetidas a diferentes manejos alimentares. O experimento foi realizado no Centro de Desenvolvimento de Aquicultura e Pesca, localizado em Itajaí-SC. Foram utilizados 360 alevinos de tilápia-do-nilo, distribuídos em 18 tanques-rede com capacidade de 1,0 m³, instalados num viveiro de 300 m². O delineamento foi um bi-fatorial (2 horários vs 3 formas de ofertar) casualizados em blocos com três repetições, totalizando 6 tratamentos. Todos os tratamentos receberam a mesma quantidade diária de dieta, alterando apenas o horário e as taxas de alimentação em cada refeição. Oxigênio dissolvido e temperatura da água foram monitorados diariamente. Amônia, nitrito, pH, transparência, alcalinidade e dureza foram realizados semanalmente. Após 40 dias foram avaliados peso final, ganho de peso diário, conversão alimentar, sobrevivência, produtividade, índice gordura visceral, retenção e excreção de nitrogênio. Não houve diferença significativa entre os tratamentos para nenhum dos fatores analisados. Conclui-se que nas condições experimentais avaliadas o horário e as diferentes distribuições da quantidade de alimento por alimentação não interfere os índices produtivos, corporais, assim como a capacidade de reter nitrogênio de juvenis de tilápia submetidos aos mesmos parâmetros de qualidade de água.

Author(s):  
T. Guha ◽  
A. Q. Siddiqui ◽  
P. F. Prentis

Tilapia, Oreochromis niloticus, is an economically important fish in Saudi Arabia. Elucidation of reproductive biology of this species is necessary for successful breeding program. In this paper we describe fine structure of testicular sperm cells in O, niloticus.Testes from young adult fish were fixed in gluteraldehyde (2%) and osmium tetroxide (1%), both in cacodyl ate buffer. Specimens were processed in the conventional way for electron microscopy and thin sections of tissues (obtained by cutting the blocks with a diamond knife) were stained by ura- nyl acetate and lead citrate. These were examined in a Carl Zeiss electron microscope operated at 40 kV to 60 kV. Sperm cells were obtained from testes by squeezing them in cacodyl ate buffer. They were fixed in gluteraldehyde (2%) in the same buffer, air dried, gold coated and then examined in a Philips scanning electron microscope (SEM) operated at 25kV.The spermatozoon of O. niloticus is consisting of head, midpiece and tail (Fig. 1).


Author(s):  
T. Guha ◽  
A. Q. Siddiqui ◽  
P. F. Prentis

The Primary Spermatocytes represent a stage in spermatogenesis when the first meiotic cell division occurs. They are derived from Spermatogonium or Stem cell through mitotic division. At the zygotene phase of meiotic prophase the Synaptonemal complex appears in these cells in the space between the paired homologous chromosomes. Spermatogenesis and sperm structure in fish have been studied at the electron microscope level in a few species? However, no work has yet been reported on ultrastructure of tilapia, O. niloticus, spermatozoa and spermatogenetic process. In this short communication we are reporting the Ultrastructure of Primary Spermatocytes in tilapia, O. niloticus, and the fine structure of synaptonemal complexes seen in the spermatocyte nuclei.


2016 ◽  
Vol 2 (2) ◽  
pp. 63
Author(s):  
Rosmawati Rosmawati ◽  
Reza Samsudin

Penelitian ini bertujuan untuk mengetahui dosis asam formiat dan propionat yang tepat pada pembuatan silase darah yang dapat meningkatkan kecernaannya pada ikan nila (Oreochromis niloticus). Rancangan percobaan pada penelitian ini adalah Rancangan Acak Lengkap dengan 6 perlakuan dan 3 ulangan. Perlakuan yang diberikan adalah perlakuan kontrol (Darah tanpa disilase), silase dengan dosis asam foemiat dan propionat (3:0%; 2,25:0,75%; 1,5:1,5%; 0,75:2,25%; 0:3%). Ikan yang digunakan dalam penelitian ini adalah ikan nila dengan bobot rata-rata 7,0 gram/ekor dengan padat tebar 20 ekor/akuarium. Parameter yang diamati yaitu nilai kecernaan protein, kecernaan lemak, kecernaan energi, dan kecernaan total. Hasil penelitian ini menunjukan bahwa pemberian dosis asam yang berbeda memberikan pengaruh yang berbeda nyata (P<0,05) terhadap nilai kecernaan protein, kecernaan lemak, kecernaan energi, dan kecernaan total pada ikan nila. Perlakuan pemberian silase dengan dosis asam formiat dan propionat 1,5:1,5% dapat meningkatkan nilai kecernaannya pada ikan nila, dengan nilai kecernaan protein 94,66%, kecernaan lemak 88,71%, kecernaan energi 92,58%, dan kecernaan total 90,27%.Kata kunci : Silase darah, Asam formiat dan propionat, Kecernaan, Ikan Nila


PubVet ◽  
2018 ◽  
Vol 12 (8) ◽  
pp. 1-9
Author(s):  
Luis Arthur Rodrigues de Andrade ◽  
Tatiana Maslowa Pegado de Azevedo

Author(s):  
Arne A Ratulangi ◽  
Reiny Tumbol ◽  
Hengky Manoppo ◽  
Henneke Pangkey

This study aims to apply vaccination against bacterial disease. The purpose of vaccination is to trigger the immune respone both non-specific and specific of fish against bacteria Motile Aeromonas Septicaemia (MAS) caused by Aeromonas hydrophila. The vaccination for fish with different ages: 2-3 weeks and 5 weeks were done using immersion method. The fish were re-vaccinated (booster) after two weeks of the first vaccination. The survival rate was < 50 % for juveniles 2-3 weeks and > 50% for juveniles 5 weeks. Survival rate for juveniles 5 weeks was higher than juveniles of 2-3 weeks. This shows that organs of juveniles of 5 weeks were more complete than the 2-3 weeks juveniles. The age of fish is one of the important factors for successfully vaccination. Penelitian ini bertujuan untuk melakukan penerapan vaksinasi terhadap penyakit bakterial. Vaksinasi ditujukan untuk merangsang respon kekebalan non- spesifik dan spesifik pada tubuh ikan terhadap penyakit Motile Aeromonas Septicaemia (MAS) yang disebabkan oleh bakteri Aeromonas hydrophila. Vaksin diberikan pada benih ikan nila yang berbeda umur yaitu 2-3 minggu dan 5 minggu dengan menggunakan metode perendaman. Ikan divaksinasi ulang (booster) setelah 2 (dua) minggu dari vaksinasi yang pertama. Prosentase kelangsungan hidup < 50 % untuk benih umur 2-3 minggu dan > 50% untuk benih umur 5 minggu. Jumlah kematian benih umur 2-3 minggu lebih tinggi dari 5 minggu. Hal ini menunjukkan bahwa fungsi organ benih umur 5 minggu telah lebih lengkap dari pada benih umur 2-3 minggu. Umur ikan merupakan salah satu faktor penting penentu keberhasilan suatu kegiatan vaksinasi.


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