Live Feeds: Microbial Assemblages, Probiotics and Prebiotics - Aquaculture Nutrition: Gut Health, Probiotics and Prebiotics - page 419

16 Live Feeds: Microbial Assemblages,

Probiotics and Prebiotics

José Pintado 1 , Miquel Planas 1 and Pavlos Makridis 2
1 Instituto de Investigacións Mariñas (IIM-CSIC), Vigo, Galicia, Spain
2 Biology Department, University of Patras, Rio, Greece

ABSTRACT

Rearing of most species of marine fish larvae relies on the use of live feeds. Bacteria in and
associated with live feeds have a major influence on the microbiota of larvae. Live feed can
be a vector of entry of specific pathogens or non-specific opportunistic bacteria to the larvae.
Basic knowledge on bacterial communities associated with live feeds and the development of
methods to control bacterial microbiota in live feed production are crucial to enhance larval
survival. Environmental and health concerns have resulted in a progressive reduction of the
use of chemotherapeutics and in a search for alternatives, based on considerations of bacteria
as an active part of rearing ecosystems. The present chapter discusses bacterial aspects of live
feed, reviews the use of probiotics and prebiotics as a strategy to improve live feed cultures,
and also considers the use of live feed as a vector to supply prebiotics and probiotics to fish
larvae cultures.

16.1 INTRODUCTION

Live feeds are necessary in the rearing of most species of marine fish larvae as the digestive
system is not yet fully developed during the early developmental stages and the larvae are
unable to capture and ingest artificial diets (Conceiçao et al. 2010). Initially, larvae are fed
on rotifers and Artemia . Due to their small size and slow swimming velocity, rotifers, such as
Brachionus plicatilis , are a suitable and widely used prey in first feeding of fish larvae (Dhert
et al. 2001). Artemia are able to form cysts, which facilitates storage and culture, and different
life stages of Artemia (nauplii, metanauplii and adults), with sizes adapted to the different steps
of developing fish larvae, can be offered to fish larvae (Dhont and Lavens 1996). Copepods are
the natural prey in most fish species in nature, being considered more adequate than rotifers
and Artemia because of their high nutritional value, with higher contents in unsaturated fatty