Physiological responses of pirarucu (Arapaima gigas) to acute handling stress

Abstract

Pirarucu (Arapaima gigas) is an obligatory air-breathing fish from the Amazon basin. Previous study showed that pirarucu juveniles present a latency period in their response to moderate stress (transportation). Therefore the objective of this study was to verify the effects of a prolonged air exposure stress in lactate, glucose, cortisol, haematocrit, haemoglobin, and liver glycogen in pirarucu. Thirty-six fish were handled by netting and subjected to air exposure for 75-min. Six fish were sampled before handling and at 0, 6, 24, 48, and 96h after handling. Fish cortisol, lactate and haematocrit rose after handling, returning to previous unstressed values on the following sampling (6h after handling). Glucose increased significantly after handling and that was maintained for 24 h. There were no changes in haemoglobin and liver glycogen as a consequence of handling. The results demonstrate a quick response when exposed to an acute stressor and a fast recovery, suggesting that pirarucu does not use their glycogen reserves during an acute stress. The results suggest that pirarucu exhibit physiological stress responses to handling similar in magnitude to those previously documented for many teleostean fishes, including salmonids.KEYWORDS: Pirarucu, Stress, Air exposure, Glycogen, Cortisol, Glucose, Lactate, Haematocrit. Resposta fisiológica de estresse em pirarucu (Arapaima gigas) submetido ao manuseio RESUMOO pirarucu (Arapaima gigas) é um peixe de respiração aérea obrigatória da bacia Amazônica. Estudo prévio demonstrou que juvenis de pirarucu apresentam um período de latência em sua resposta de estresse a um estresse moderado (transporte). Desta forma, o objetivo deste estudo foi verificar os efeitos de uma exposição aérea prolongada no lactato, glicose, cortisol, hematócrito, hemoglobina e glicogênio do fígado em pirarucu. Trinta e seis peixes foram manuseados com um puçá e expostos ao ar por 75-min. Seis peixes foram amostrados antes do manuseio e 0, 6, 24, 48, e 96h após o manuseio. O cortisol, lactato e hematócrito aumentaram após o manuseio, retornando para valores semelhantes ao de antes do manuseio na amostragem seguinte (6 h após o manuseio). A glicose aumentou significativamente após o manuseio e o aumento se manteve até a amostragem de 24h. Não houve mudança significativa na hemoglobina e no glicogênio como conseqüência do manuseio. Os resultados demonstram que o pirarucu apresenta uma rápida resposta e uma rápida recuperação quando exposto a um estressor agudo e sugerem que o pirarucu não usa suas reservas de glicogênio nesta situação. Os resultados indicam que o pirarucu apresenta uma resposta fisiológica de estresse similar em magnitude com muitos outros teleósteos, incluindo os salmonídeos.

Menthol as anaesthetic for lambari Astyanax altiparanae (Garutti & Britski 2000): attenuation of stress responses

“…; Acerete et al . ; Costas, Conceição, Aragão, Martos, Ruiz‐Jarabo, Mancera & Afonso ) and therefore a procedure widely used to assess the effects of acute stress in fish research (Sloman, Taylor, Metcalf & Gilmour ; Morales, Cardenete, Abellán & García‐Rejón ; Gomes ; Ramsay, Watral, Schreck & Kent ).…”

Effect of density on survival, physiological parameters and water quality during pirarucu transportation in open system

“…For C. gariepinus capture with nets for sampling after transportation may not have been as stressful as the initial handling, the main responsible for elevation in cortisol levels. Handling is inevitable for transportation and may cause mechanical abrasion, induce stress, exhaustion (Ross, & Ross, ), and increased cortisol levels (Barcellos, Volpato, Barreto, Coldebella, & Ferreira, ; Gomes, ).…”

Low Genetic Diversity and Structuring of the Arapaima (Osteoglossiformes, Arapaimidae) Population of the Araguaia-Tocantins Basin

“…As the arapaima prefers the lentic environments, such as flooded forests, rivers and lakes, of the Amazon, Araguaia-Tocantins and Essequibo basins ( Castello and Stewart, 2010 ; Castello et al, 2013 ), its populations become increasingly concentrated during the dry season, and the high densities of fish that accumulate during this period greatly increase their vulnerability to capture. Given this vulnerability of the species to fishing and the reduction of its stocks in recent years, researchers have focused increasingly on its genetic diversity and population structure ( Farias et al, 2003 ; Hrbek et al, 2005 , 2007 ; Hrbek and Farias, 2008 ; Hamoy et al, 2008 ; Araripe et al, 2013 ; Vitorino et al, 2015 ), chromosomal evolution ( Marques et al, 2006 ), and other aspects of its biology ( Gomes, 2007 ; Castello, 2008a , b ; Arantes et al, 2010 ; Fernandes et al, 2012 ; Farias et al, 2015 ).…”