Feeding frequency on Lophiosilurus alexandri: performance, hematology, and daily rhythms

ABSTRACT

The aim of the present study was to evaluate the different feeding frequencies on the performance, hematology profile, daily rhythms of glucose and activities digestive enzymes for juvenile Lophiosilurus alexandri. Feeding frequency did not affect survival, final weight, daily weight gain (P > .05). Glucose showed a daily rhythmic variation, with the acrophase in the group F2 located at Zeitgeber Time (ZT) 12.51 h and at ZT 13.33 h in the group F5. The daily rhythms in digestive enzymes were also affected, especially chymotrypsin, whose activity was twofold higher in F5 than F2. Food ratio divided into a higher frequency along the day induces an increase in acid protease and chymotrypsin activities. Different feeding frequencies can influence hematology profile, daily rhythms of glucose and activities digestive enzymes. The production of juvenile L. alexandri can be successfully carried out adopting a feeding frequency of twice a day.

KEYWORDS:

• Biological rhythms
• digestive enzyme
• feeding time
• glucose
• pacamã

Availability of data and material

The data that support the findings of this study are available from the first author, Lucas Pedro Gonçalves Junior upon reasonable request.

Code availability

Not applicable

Consent to participle

All names in the author list have been involved in various stages of experimentation or writing.

Disclosure statement

No potential conflict of interest was reported by the authors.

Ethics approval

Two experiments were carried out at the Laboratório de Aquacultura (Laqua) of the Escola de Veterinária, Universidade Federal de Minas Gerais (UFMG), according to the methodology approved by Ethical Commission on Animal Use – CEUA (protocols 31/2011 and 230/2016).

Additional information

Funding

The present research was funded by Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPq-Brazil, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES-Brazil, and Fundação de Amparo a Pesquisa de Minas Gerais-FAPEMIG-Brazil, including Ronald K. Luz (CNPq-Proc. 308547/2018-7). José F. López-Olmeda was also funded by a “Ramón y Cajal” research fellowship granted by the Spanish Ministry of Science (RYC-2016-20959).