Objective
The purpose of the research is to ascertain the possibility of rearing a species which has not yet been introduced into European countries. The species Paralichthys olivaceus (flounder or hirame in Japanese), of the Pleuronectiformes order, is one of the most commonly reared marine teleosteans in Japan and it has a fast growth rate. It should be pointed out that the entire productive cycle is carried out in tanks, differently from the other species. The main aim of the research is to foster the productive diversification of marine aquaculture rearing, and in particular of rearing in tanks, using species which show faster growth rate and/or higher strength in comparison with the autochthonus species which are presently being reared.
Fertilized Paralichthys olivaceus eggs were imported from Japan in compliance with quarantine rules. The transportation was carried out in polyethylene bags filled with 40% seawater and 60% oxygen. The survival rate after transportation was 93%.
Incubation of the eggs was carried out at 16 C and 34 parts per thousand (ppt) salinity. The average hatching rate was 85%. At the beginning stocking density was about 50 larvae l{1}. The rearing tanks were supplied daily with microalga Tetraselmis suecica up until 25 days after hatching (DAH). The larvae were fed rotifers up to the 34 DAH and Artemia naupli from 21 DAH to 60 DAH. Artificial food was the exclusive feed from 60 DAH. Metamorphosis started on 30 DAH and was completed by 45 DAH.
The average survival rate were 80% at 10 DAH and 45% at 85 DAH. The average total lengths were 7.9 mm at 10 DAH and 38.4 mm at 80 DAH, with an average daily increment of about 0.44 mm.
The frequency of occurrence of albinism in P olivaceus juveniles was recorded and decreased when using different larval diets. The rotifers supplied to the larvae were cultured on different species of microalgae and/or enriched by commercial product with a high ratio of docosahexaenoic (22:63) acid (DAH) and eicosapentaenoic (20:53) acid (EPA).
The phenomenon of pigmentation recovery for specimens from 60 mm to 180 mm (total length) was also observed and the majority of the pseudoalbinic specimens recovered 80% to 95% of the coloured area on the ocular side. The anomalies of skeletal apparatus involving vertebrae, fin rays, operculum and skull were investigated and classified.
The more suitable stocking densities were verified for juveniles ranging from 4 cm to 12 cm (total length).
The conversion ratio for juveniles gave 1:1.8 (1 kg of food: 1.8 kg of biomass). The fry rearing has been continued in order to develop a broodstock.
The purpose of the project is to develop and adapt the rearing techniques of this species. In several phases fertilized eggs will be imported from Japan and hatched. Larval and post-larval rearing will be carried out up to the 4th month of life. Nutritional and environmental conditions will be monitoring. The juveniles will be weaned using different diets and they will be reared up to the commercial size. Particular attention will be given in order to form a broodstock. The results obtained will be compared with Japanese experience
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
- agricultural sciencesagriculture, forestry, and fisheriesfisheries
- medical and health scienceshealth sciencesnutrition
- agricultural sciencesagricultural biotechnologybiomass
You need to log in or register to use this function
Programme(s)
Topic(s)
Data not availableCall for proposal
Data not availableFunding Scheme
Data not availableCoordinator
70042 Mola di Bari
Italy