Energy budgets for juvenile Pacific whiteleg shrimp Litopenaeus vannamei fed different diets

Daniel Lemos,Fanny Ayumi Yasumaru,Rafael Tsuyoshi Inoe Coelho,Maria José Arruda Campos Rocha Passos,Vicente Gomes

doi:10.1590/s1679-87592019024306701

Abstract

Abstract Energy budgets for juvenile Pacific whiteleg shrimp, Litopenaeus vannamei (1.7-4.0 g ) fed with different diets were assessed. The energy partitioning between growth, respiration, ammonia excretion, feces and exuvia was calculated to estimate for total food energy intake. Shrimp oxygen consumption and ammonia excretion were quantified in sealed chambers (25°C, 34 ppt). Energy allocated for growth and feces were obtained from the wet combustion of whole body and feces samples, exuvia was estimated as 10% growth energy. Three diets were tested: 100% chopped fish (Fish), 100% commercial feed (Feed), and 50-50% chopped fish and commercial feed (Mix). Most of the energy from the diets was channeled into respiration (49.7-70.5%). Shrimp fed the Feed diet used more energy in growth (24.4%) than those fed Mix (13.4%) or Fish diets (13.2%), either in absolute (joule) or relative (% of ingested energy) terms. Conversely, energy loss as ammonia excretion was lower in shrimp fed Feed (1.0%) compared to shrimp fed Mix (4.2%) or Fish diets (7.8%). Less energy was lost in feces by shrimp fed Fish diet (7.3%) compared to Mix (20.2%) and Feed diets (22.2%). The calculated energy intake by shrimp fed Fish, Mix and Feed were 0.995, 1.100, and 1.255 kJ ind-1day-1, respectively. According to the O:N atomic ratios (oxygen consumed to nitrogen excreted), protein tented to be the predominant substrate catabolized by shrimp fed Fish (O:N=16±5.2), and Mix (O:N=25±11.6), with increasing use of carbohydrates and/or lipids in the Feed (O:N=74±37.3). Results suggest diet composition may affect energy budget and partitioning differently between metabolism and growth either in absolute or relative terms, as shrimp fed Fish and Mix diets used protein as main substrate for metabolism, whereas shrimp fed Feed diet channeled protein for growth, and lipids and carbohydrates for other metabolic functions.

Highlights

The efficient use of ingested food energy between metabolism and growth may be a requisite for the successful existence of any species
Mean specific total ammonia nitrogen (TAN) excretion was reduced in shrimp fed the Feed diet and are significantly lower (p
Energy content was higher in shrimp fed Mix and Feed diets (11.67±0.71 and 12.30±0.79 J mg-1 dry matter (DM), respectively) than in Fish diet (8.37±1.13 J mg-1 DM)

Summary

Introduction

The efficient use of ingested food energy between metabolism and growth may be a requisite for the successful existence of any species. The energy acquired via food intake is channeled between the vital process of activities of growth, metabolism, ammonia excretion, feces, and, in the case of shrimp, molting (Jobling, 1993; Lemos and Phan, 2001; Petrusewicz and Macfadyen, 1970). The partitioning of the ingested energy between these processes may depend on variables such as shrimp life stage (Lemos and Phan, 2001; Maldonado et al, 2009), dietary composition (Gauquelin et al, 2007; JiménezYan et al, 2006; Suárez et al, 2009; Wang et al, 2006), and environmental factors (Rosas et al, 2001; Su et al, 2010; Wang et al, 2006; Yan et al, 2007; Ye et al, 2009). The ratio of energy partitioned between growth and other metabolic processes may represent the efficiency of energy utilization (Duncan and Klekowski, 1975)

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