Prebiotic Applications in Shellfish - Aquaculture Nutrition: Gut Health, Probiotics and Prebiotics - page 409

from xylan-rich materials (Vázquez et al. 2000). There remains a paucity of research on the
use of XOS in shellfish species, with only one study on L. vannamei published (Wang et al.
2010). Wang and colleagues (2010) observed that XOS provided enhancements in feed effi-
ciency and immune parameters (increased peroxidase activity, superoxide dismutase activity,
lysozyme activity, phenoloxidase activity and serum albumin levels) when fed at 0.3 g kg -1 .
Enhanced feed conversion was also reported at varying dietary levels of 0.1-0.5 g kg -1 and
shrimp total body protein was increased with supplementation at 0.1 g kg -1 XOS.
15.2.5 Inulins
Inulins are naturally occurring fructans with a degree of polymerization of 2 to 60. Inulin is
mainly extracted from chicory roots; however it can be found in a variety of common foods
such as garlic, onion, artichoke and asparagus (Van Loo et al. 1995). As with XOS, the use of
inulin appears to be limited in shellfish. A study by Hoseinifar et al. (2010) supplied a com-
mercial source of inulin (Raftiline ST) via Artemia to Indian white shrimp ( Fenneropenaeus
indicus ) larvae and post larvae. No significant effect of inulin was recorded on shrimp growth
for either larvae or post larvae stages, nor was survival affected during larval stages. However,
significant increases in survival were observed in post larvae at 22 days post hatching.
15.2.6 Other prebiotics
The application of the commercial prebiotic GroBiotic-A ® , a mixture of partially autolysed
brewer's yeast, dairy components and fermentation products including oligosaccharides
(Gatlin et al. 2008), has been reported to have no effect on the growth or survival of Pacific
white shrimp under non-challenged conditions (Li P. et al. 2009). However, the study
also reported elevated survivability of L. vannamei fed 2% GroBiotic-A ® after a salinity
challenge.
Other established prebiotics such as galactooligosaccharides (GOS) and arabinoxyloo-
ligosaccharides (AXOS) have shown potential in teleost species ( Chapter 14 ) but no reports
of their use in crustacean species are available at present.
15.3 PREBIOTIC BENEFITS
Documented prebiotic studies in shellfish often focus on growth, survival and disease resis-
tance, though fewer studies have sought to elucidate the causative actions behind these apparent
benefits. Causative actions highlighted to date include enhanced immune status (Li etal. 2007;
Hai and Fotedar 2009; Sang et al. 2009; 2011a; 2011b; Sang and Fotedar 2010; Zhang et al.
2011), improved GI morphology (Daniels et al. 2010; Sang and Fotedar 2010), modulated GI
microecology (Li et al. 2007; Zhou et al. 2007; Daniels et al. 2010; 2013; Sang and Fotedar
2010; Zhang et al. 2011) and enhanced digestive enzyme activity within the GI tract (Wang
et al. 2010). It is evident that there is likely to be a complicated suite of interactive effects,
which work concomitantly to bring about the observed host benefits. Despite a lack of compre-
hensive studies which focus on the mechanistic actions which underpin the prebiotic success
commonly reported in shellfish, it is documented that prebiotics can improve shellfish survival,
immune status, disease resistance, growth performance and feed utilization (Table 15.1).