Development of a low-cost technology for mass production of the free-living nematode Panagrellus redivivus as an alternative live food for first feeding fish larvae

Abstract

The free-living nematode Panagrellus redivivus is a suitable food source for first feeding fish. In the present report, a new method for the mass production of P. redivivus is presented. The technique involves multiplication of the nematode in monoxenic (single microorganism: Saccharomyces cerevisiae) solid culture (fluid media supported by 1- to 4-cm(3) sponge cubes) in autoclavable plastic bags (size range: 50 x 30 cm to 75 x 67 cm). Two growing media were tested: oat-meal medium (OM), which is an oat-based medium (16.7% oat-meal flour in 0.8% saline solution), and purified ingredient medium (PIM), a semi-synthetic medium (1.64% meat peptone, 0.94% yeast extract, 12.6% corn starch, 0.24% glucose, 1.48% sunflower oil, in 0.8% saline solution). The bags were inoculated with 350 nematodes/g medium. After an average period of 12 days (11-13 days) at 25 degrees C, the average yield (number of nematodes/g medium) was 241 x 10(3) for OM and 333 x 10(3) for PIM in 12-l bags (50 x 30 cm). The production scale has currently reached a bag volume of 50 l (75 x 67 cm); using PIM and the conditions described above, it was possible to harvest more than 1.3 x 10(9) nematodes/bag (291 x 10(3) nematodes/g medium). In PIM, when sun flower oil was replaced with the same amount of fish oil or cod liver oil, yields of 259 x 10(3) and 290 x 10(3) nematodes/g medium, respectively, were attained. The technology for mass production and formulation of P. redivivus should enable fish-hatchery operators to rely on a cheap, standardised, and permanently available live food product for first feeding fish larvae.

Effect of different lipid extraction methods on δ13C of lipid and lipid-free fractions of fish and different fish feeds

“…The marine diatom Ditylum brightwellii was produced in 10 litre flasks on f=2 medium with silicate according to Guillard and Ryther [10]. The free-living nematode Panagrellus redivivus was mass produced with a technology described by Ricci et al [11]. Frozen material of mixed freshwater zooplankton was obtained from Fischzucht Riegger, Ettenheim, Germany.…”

Mass produced nematodes Panagrellus redivivus as live food for rearing carp larvae: preliminary results

“…Recently, large‐scale production processes have been developed for entomopathogenic nematodes. Combining the expertise in the fields of entomopathogenic nematode production and fish nutrition, a new method for the mass production of P. redivivus has been developed, which involves the multiplication of nematodes in aerated plastic bags in monoxenic solid culture (Ricci, Fifi, Ragni, Schlechtriem & Focken 2003). A sterile medium is inoculated with P. redivivus and yeast.…”

Consumption and prey size selection of the nematode Caenorhabditis elegans by different juvenile stages of freshwater fish

“…In aquaculture, the larvae of some fish species are fed routinely with meiobenthic organisms (rotifers or Artemia eggs) until they are able to accept fish pellets. In the last few years, efforts have been made to use nematodes as a food source for fish larvae (Ricci et al, 2003;Schlechtriem et al, 2004Schlechtriem et al, , 2005Honnens & Ehlers, 2013).…”