Banca de DEFESA: RAFAEL CARVALHO DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RAFAEL CARVALHO DA SILVA
DATE: 29/10/2021
TIME: 09:00
LOCAL: INSTITUTO DE ZOOTECNIA
TITLE:

Anesthetic Effect and Acute Toxicity of Citrus sinensis Essential Oil on Betta splendens.

KEY WORDS:

Orange, Ornamental fish, Transport, Welfare.

PAGES: 41
BIG AREA: Ciências Agrárias
AREA: Zootecnia
SUMMARY:

The Citrus sinensis essential oil (EOCS) has sedative and anesthetic properties, thus constituting an alternative to synthetic anesthetics commonly used in aquaculture. The beta Betta splendens fish species is known for its beauty, wide variety of body shapes and colors, and also for its pronounced aggressiveness in adult males. Thus, this work aimed to study the acute toxicity of EOCS on B. splendens, the times of induction and recovery from anesthesia, its action on the agonist behavior of adult males and its effects on the collective transport of males of this species. In the acute toxicity test for 48h exposure, the concentrations 0 + 540 μL L−1 of ethanol (control), 20, 30, 40, 50 and 60 μL L−1 of EOCS were tested, with six repetitions each. Then, an assay was performed to evaluate the times of induction and recovery from anesthesia (N=6), where the concentrations 0 + 2700 μL L−1 of ethanol (control), 25, 50, 100, 150, 200, 250 and 300 μL L−1 of the EOCS were evaluated, with six repetitions for each treatment. The evaluation of agonist behavior among males of B. splendens exposed to the EOCS was performed by exposing the animals to the EOCS during agonistic encounters, with concentrations of 0 + 270 μL L−1 of ethanol, 10, 20 and 30 μL L−1, with six repetitions for each treatment. For the 6h transport assay, the concentrations of 0.0 or 20 μL L−1 of EOCS were used, with four replicates each, and such dosages were defined based on the previous tests. In this study, the collection of gills was also performed to assess possible histological damage during exposure to the EOCS during the transport period. Regarding the EOCS acute toxicity test, the results show that the EOCS 48h LC50 was calculated at 49.17 μl L-1. In the EOCS induction experiment, fish reached different anesthetic stages, and no mortalities were observed during fish induction or recovery. OECS concentrations from 250 μL L−1 were required to induce B. splendens to anesthesia in an adequate time, about 3.3 minutes. The addition of EOCS to the transport water of male B. splendens allowed the animals to maintain their body state at the end of transport with the product, without any apparent external damage caused by agonist behavior, unlike animals transported in water only, which they were more agitated, exhibiting color changes and with damaged fins, caused by disputes between the animals. The results showed that the EOCS has the potential to act as an aggression-reducing agent in this species. No histological changes were observed in the gills of fish exposed to 20 μl L-1 of the EOCS during transport. Thus, it is concluded that the LC50 in 48h of the EOCS is 49.17 μl L-1. The EOCS proved to be an effective and safe anesthetic for B. splendens. In addition, the concentration of 20 μl L-1 of the EOCS is recommended for the collective transport of males of this species, since no alterations at the histological level were observed in fish exposed to this concentration.

BANKING MEMBERS:
Externa à Instituição - JANE MELLO LOPES - UFMA
Presidente - 2376201 - LEONARDO ROCHA VIDAL RAMOS
Interno - 3067308 - MATHEUS PEREIRA DOS SANTOS