Nikos Vlahos

• PhD
• Technological Educational Institute of Messolonghi

The use of Mediterranean euryhaline fish and halophytes in aquaponics presents a sustainable and alternative approach to food production. The present study investigates the effect of compensatory growth on sea bass (Dicentrarchus labrax) and Baltic prawn (Palaemon adspersus) co-cultivated with the halophytic glasswort (Salicornia europaea). Three a...

The aim of this study was to evaluate the effect of starvation and refeeding on the growth and food intake of gilthead seabream ( Sparus aurata ) and seabass ( Dicentrarchus labrax ) and on the growth and nitrogen uptake of glasswort ( Salicornia europaea ) in a polyculture aquaponic system under 12 ppt salinity for 75 days. Nine small-scale autono...

The possibility of simultaneous production of halophyte and euryhaline fish creates huge interest in both commercial aquaponics systems and in research. The aim of the present study was to investigate the effect of three different salinities (8, 14, and 20 ppt) on the growth performance and survival rate of sea bream (Sparus aurata) and rock samphi...

Aquaponics is a promising cultivation technique for combined production of crops and fish, on the condition of tackling certain nutrients deficiencies. The aim of the present study was to examine the limitations imposed by the system on spinach (Spinacia oleracea) growth and functional performance and to identify the minimum nutrient supplementatio...

The aim of this study is to investigate the effect of 10 and 20% replacement of fishmeal (FM dietary group) with the superworm Zophobas morio larvae meal (ZM10 and ZM20 dietary groups) on the growth performance of sea bass (Dicentrarchus labrax) and lettuce plants (Lactuca sativa) reared in aquaponics. Ninety juvenile sea bass with an average body...

In aquaponics, a closed-loop system which combines fish and crop production, essential nutrients for plant growth are often at sub-optimal concentrations. The aim of the present study was to identify system limitations and thoroughly examine the integrated response of its components to minimal external inputs, notably crop’s functional parameters,...

This study evaluated the effects of different dietary protein levels on growth performance and nutrient utilization of snarpsnout sea bream (Diplodus puntazzo) juveniles. Five isoenergetic diets were formulated to contain a dietary protein level at 30% (P30), 35% (P35), 40% (P40), 45% (P45) and 50% (P50). Each diet was randomly assigned to triplica...

The sea bass is one of the most important species of the Mediterranean, and especially of Greece. Individuals with different number of vertebrae have been reported. This number ranges from 24, 25 to 26 vertebrae. In this study a sample of 73 individual of sea bass were collected from fish farms and divided into three age groups. The first group...

Following a meal, a series of physiological changes occurs in fish as they digest, absorb and assimilate ingested nutrients. This study aims to assess post-prandial free amino acid (FAA) activity in gilthead sea bream consuming a partial marine protein (fishmeal) replacement. Sea bream were fed diets where 16 and 27% of the fishmeal protein was rep...

The aim of this study is to investigate the effect of three daily fish feeding frequencies, two, four and eight times per day (FF2, FF4, and FF8, respectively) on growth performance of sea bass ( Dicentrarchus labrax )and lettuce plants ( Lactuca sativa ) reared in aquaponics. 171 juvenile sea bass with an average body weight of 6.80 ± 0.095 g were...

The European seabass is one of the most important species of the Mediterranean, specifically Greece. Individuals with different numbers of vertebrae have been reported. This number ranges from 24 to 26 vertebrae. In this study a sample of 73 individual seabass were collected from fish farms and divided into three age groups. The first group include...

For successful prawn aquaculture, feeds should be based on readily consumed ingredients that promote survival and optimal growth performance. This pilot study investigates the rearing of juvenile Baltic prawn Palaemon adspersus . Two feeding trials were carried out for 60 days; both incorporated insect meals, the first one in fishmeal‐based diets,...

Brackish aquaponics using Mediterranean fish and plants provides an alternative opportunity for a combined production of high-quality food products with high commercial and nutritional value. This is the first study that investigates the effect of two different salinities (8 and 20 ppt) on growth and survival of Sparus aurata and Crithmum maritimum...

This study aims to describe changes in the activity of digestive enzymes of the zebra cichlid, Archocentrus nigrofasciatus, from hatching until 30 d after hatch (d.a.h.), and to evaluate the effects of feeding diets with different levels of fishmeal (FM) substitution with alternative nonanimal protein sources from 30 d.a.h. up to the age of 60 d.a....

In order to conserve and culture the cichlid fish Archocentrus nigrofasciatus, more information about its reproductive biology and its larval behaviour and morphogenesis is necessary. Currently, temperatures ranging from 21°C to 27°C are used in ornamental aquaculture hatcheries. Lower temperatures are preferred in order to reduce the costs for wat...

We analysed the 16S rRNA gene diversity within the bacterioplankton community in the water column of the ornamental fish Pterophyllum scalare and Archocentrus nigrofasciatus aquaria during a 60-day growth experiment in order to detect any dominant bacterial species and their possible association with the rearing organisms. The basic physical and ch...

We analysed the 16S rRNA gene diversity within the bacterioplankton community in the water column of the ornamental fish Pterophyllum scalare and Archocentrus nigrofasciatus aquaria during a 60-day growth experiment in order to detect any dominant bacterial species and their possible association with the rearing organisms. The basic physical and ch...

Figure S1. Rarefaction curves of the wild (W), organically- (O), and conventionally (C) reared Sparus aurata (Sa) gut bacterial communities. OTUs: operational taxonomic units. Figure S2. Number of shared operational taxonomic units among the triplicate samples of the wild (W), organically- (O), and conventionally (C) reared Sparus aurata (Sa) gut b...

Changes in the relative abundance of the water column common phylotypes, at 0, 30 and 60 days, between samplings in the Archocentrus nigrofasciatus and Pterophyllum scalare rearing tanks. Figure S1. Bacteria clone library coverage based on Good’s C estimator from the water of Archocentrus nigrofasciatus and Pterophyllum scalare rearing tanks at the...

The present study examines the morphometric characters and the main morphological features of the cichlid fish Archocentrus nigrofasciatus during its yolk-sac larval development under two different temperature conditions 27 οC and 23 οC. Every 4 hours during 100 hours (4 days) after hatching, 60 specimens (30 specimens from each tank) were sampled...

In this study water bacterial diversity and abundance was compared between aquaria of ornamental fish (Archocentrus nigrofasciatus, tap water, T=20νC) and Norway lobsters (Nephrops norvegicus, seawater, T=12νC). Water from the aquaria was sampled at the beginning, the middle (30 days) and the end (60 days) of ornamental fish rearing and at the begi...

Several biogeochemical processes which are crucial for the reared organisms are mediated by prokaryotic organisms in aquaria (e.g. nitrification). However, some of these microorganisms are pathogenic or toxic. In this work, the community shift of Bacteria in experimental aquaria (40 L) of the ornamental fish Archocentrus nigrofasciatus (zebra cichl...

Heavy metals concentration in sediments of Messolonghi Lagoon (W. Greece) Total heavy metal concentrations (Zn, Cu, Ni, Co, Mn and Fe) in the surface and subsurface sediments of Messolonghi lagoon were measured. The degree of contamination of the sediments was evaluated through geo-accumulation index (Igeo) and pollution load index (PLI). ΕΙΣΑΓΩΓΗ:...

Through a gradual salinity increase, the fry (~2-3cm) of all the 5 species of Mugilidae (Mugil cephalus, Liza ramada, L. aurata, L. saliens and Chelon labrosus) can be acclimated to salinities well over 100ppt in about a month. Contrary to this, abrupt salinity changes (35-80ppt) bring about mortalities with LC50 (24-h) around 50ppt. In both proced...

The fry of Mugil cephalus, Liza aurata, L. ramada and Chelon labrosus were raised in recirculation system conditions from the size of about 3,0cm, using brackish (5-15ppt) or sea water (35ppt), and different foods (live or artificial). It was found that for a period of 77-83 days, growth performance was high at 22-23,8oC, reaching values for weight...

In experiments using a respirometer and a small recirculating system, the oxygen consumption and oxygen concentration were monitored for the fry of Liza ramada and Mugil cephalus. It was found that consumption and fish size were inversely related and this relation intensifies as temperature increases. Additionally the consumption is increasing as t...

Αναλύεται η διαδικασία με την οποία προκαλούμε ωοτοκία, γονιμοποίηση και κατόπιν αρχική θρέψη των λαρβών σε ενυδρεία των ειδών Carassius auratus (χρυσόψαρο), Pterophyllum scalare (αγγελόψαρο), Oreochromis aureus (τιλάπια) στις εγκαταστάσεις του τμήματος Ιχθυοκομίας-Αλιείας του Τ.Ε.Ι. Μεσολογγίου.

Εξηγείται συνοπτικώς το πως προκαλείται η απελευθέρωση των αυγών στο χρυσόψαρο Carassius auratus σε ενυδρεία μέσω της απότομης ανύψωσης της θερμοκρασίας.