George N Hotos

George N Hotos
University of Patras | UP · Animal Production Fisheries and Aquaculture

M Sc, Ph D

About

98
Publications
20,200
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462
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March 1986 - August 2020
University of Patras Greece
Position
  • Professor
Description
  • Teaching, researching in the plankton culture lab, lecturing in public meetings on aquaculture, plankton research, conservation of lagoonal life.

Publications

Publications (98)
Article
Full-text available
On the quest of discovering novel local strains of microalgal species that can be effectively cultured with industrial perspectives, two cyanobacterial strains Anabaena sp. and Cyanothece sp. were isolated from the lagoonal and saltworks waters of the Messolonghi lagoon (W. Greece). They were batch cultured at 20–21.5 °C in six combinations of thre...
Article
Full-text available
In the quest of finding local strains of marine ciliates that can be easily cultured under a broad range of salinity and fed with microalgae, Fabrea salina Henneguy, 1890 and Condylostoma sp. Bo-ry de St. Vincent, 1826 were cultured for 22 days in small volumes at a temperature of 16–18 °C and fed with flagellated microalgae. F. salina presented a...
Article
Full-text available
Two local marine cyanobacteria, Phormidium sp. and Cyanothece sp., were batch-cultured under 18–19.5 °C, at 40 ppt salinity, using white LED light of low (40 μmol photons/m2/s) and high (160 μmol/m2/s) intensity and, additionally, blue, green and red LED light. Yield was highest in high white light in both species (2.15 g dw/L in Phormidium, 1.47 g...
Technical Report
Full-text available
A detailed analytical procedure is described here for the measurement of phycobiliprotein cell content in cyanobacterial cultures. The core of the procedure is the extraction of the phycocyanin, allophycocyanin and phycoerythrin from the algal mass by means of freezing and thawing which proved very effective. Afterwards all biliproteins were measur...
Preprint
Cyanobacteria are extensively studied and cultured because they can produce many value-added substances among which are pigments, mainly the phycobiliproteins phycocyanin (PC), phycoerythrin (PE), allophycocyanin (APC) and chlorophyll-a and carotenoids as well. As numerous cyanobacterial species await optimization for maximizing pigment production,...
Article
Full-text available
After a 1.5-year screening survey in the lagoons of Western Greece in order to isolate and culture sturdy species of microalgae for aquaculture or other value-added uses, as dictated primarily by satisfactory potential for their mass culture, five species emerged, and their growth was monitored in laboratory conditions. Amphidinium carterae, Nephro...
Preprint
After a 1.5 year screening survey in the lagoons of Western Greece in order to isolate and culture sturdy species of microalgae for aquaculture or other value added uses, as dictated primarily by a satisfactory potential for their mass-culture, five species emerged and their growth was monitored in laboratory conditions. Amphidinium carterae, Nephr...
Article
Full-text available
A strain of the filamentous non N-fixing cyanobacterium Phormidium sp. isolated from the Messolonghi (W. Greece) saltworks, was cultured in the laboratory at six different combinations of salinity (20-40-60 ppt) and illumination (low-2000 lux and high-8000 lux). At salinities of 60 and 40 ppt and in high illumination (XL-8000 lux), the growth rate...
Technical Report
Full-text available
Περιγράφονται (μαζί με αντιπροσωπευτικές φωτογραφίες) τα είδη των μικροφυκών που απομονώθηκαν από το 2019 και εντεύθεν από τα αλμυρά νερά των λιμνοθαλασσών της Δ. Ελλάδας στο πλαίσιο του ερευνητικού προγράμματος ALGAVISION. Τα είδη αυτά ήδη καλλιεργούνται στο εργαστήριο καλλιέργειας πλαγκτού στο Μεσολόγγι. Εξετάζονται οι συνθήκες για την καλύτερη α...
Preprint
A strain of the filamentous non N-fixing cyanobacterium Phormidium sp. isolated from the Messolonghi (W. Greece) saltworks, was cultured in the laboratory at 6 different combinations of salinity (20-40-60 ppt) and illumination (low-2000 lux and high-8000 lux). At salinities of 60 and 40 ppt and in high illumination (XL-8000 lux) the growth rate (μm...
Article
Full-text available
During a survey in 2015, an impressive assemblage of organisms was found in a hypersaline pond of the Messolonghi saltworks. The salinity ranged between 50 and 180 ppt, and the organisms that were found fell into the categories of Cyanobacteria (17 species), Chlorophytes (4 species),Diatoms (23 species), Dinoflagellates (1 species), Protozoa (40 sp...
Preprint
During a survey in 2015 an impressive assemblage of organisms were found in a hypersaline pond of the Messolonghi saltworks. The salinity ranged between 50 and 180 ppt and the organisms recorded fell in the categories of Cyanobacteria (17 species), Chlorophytes (4 species), Diatoms (23 species), Dinoflagellates (1 species), Protozoa (40 species), R...
Article
Full-text available
This study concerns the finding of an effective operational equation relating the measured absorbance (or O.D. - optical density) in a spectrophotometer of the suspended cells of microalgae to their cell density (c.d.) in culture in order to construct calibration curves for use in culture operations. The microalgae examined were the chlorophyte Nep...
Article
Full-text available
The collected in nature fry of Mugil cephalus, Liza aurata, L. ramada and Chelon labrosus that arrive in massive schools at the coastline of Greece were reared in small aquaria (50 L) of a recirculation system from the size of about 3.0 cm TL (50 fish per aquarium), using brackish (15 ppt) water and artificial high protein food. It was found that f...
Technical Report
Full-text available
Οι λευκοί λοφίσκοι με το σωρευμένο αλάτι στο δρόμο από το Μεσολόγγι για το Αιτωλικό παγιδεύουν το βλέμμα των ταξιδιωτών και του δηλώνουν ότι εκεί η φύση κάτι ιδιαίτερο πλάθει και προσφέρει. Πράγματι, οι αλυκές Μεσολογγίου από τις οποίες προέρχεται το αλάτι, για τον φυσιολάτρη που θα ψάξει τα ενδότερα αποτελούν με το σύμπλεγμα των λιμνών τους (έστω...
Technical Report
Full-text available
Για να γίνει η φωτοσύνθεση στα φυτά, τα φύκη, τα κυανοβακτήρια και σε ορισμένα φωτοσυνθετικά βακτηρίδια πρέπει να δεσμευτεί η ενέργεια του φωτός. Αυτό επιτυγχάνεται με τις φωτοσυνθετικές χρωστικές που είναι ειδικά μεγάλα μόρια που βρίσκονται είτε στις εσωτερικές μεμβράνες (θυλακοειδή) των χλωροπλαστών που διαθέτουν στα κύτταρά τους τα φυτά και τα ε...
Technical Report
Full-text available
Οι ζεόλιθοι, ηφαιστειογενή κρυσταλλικής δομής ορυκτά, λόγω των ειδικών προσροφητικών τους ιδιοτήτων και της συνυφασμένης με αυτές ικανότητάς των για ιοντοανταλλαγή, μπορούν να απαλλάσσουν το νερό από την τοξική αμμωνία η οποία αποτελεί τον σπουδαιότερο ρύπο και κίνδυνο για τα εκτρεφόμενα ψάρια. Σήμερα η χρήση των ζεολίθων έχει επεκταθεί και σε άλλε...
Technical Report
Full-text available
Τα κωπήποδα (copepods) των οποίων η ονομασία σημαίνει με "πόδια σαν κουπιά" είναι ένα άθροισμα μικρού μεγέθους καρκινοειδών υδρόβιων ζώων που ανευρίσκονται σε κάθε τύπο νερού, από θαλασσινό (κυρίως) έως γλυκό. Από τα 13.000 περίπου καταγεγραμμένα είδη τα 2800 ζουν στο γλυκό νερό. Τα 6500 είδη περίπου από το σύνολο των ειδών είναι παρασιτικά (σε άλλ...
Article
Full-text available
The halotolerant green single-celled Asteromonas gracilis isolated from the hypersaline saltern ponds of Messolonghi, Greece, was kept in laboratory cultures, grown effectively at various salinities and used for feeding rotifers, protozoa, copepods and Artemia sp. In all feeding trials all filter feeders accepted A. gracilis and grew. Additionally,...
Article
Full-text available
Growth and mortality of L. aurata (Risso,1810) were estimated in the lagoon of Klisova-Messolonghi (W. Greece), based on age estimation from scale readings of a total of 1048 individuals, ranging between 10 and 59 cm in total length (TL). Age determination revealed nine age classes (0+ to 8+). Maximum age was found to be 8 years for females and 6 y...
Preprint
The collected in nature fry of Mugil cephalus, Liza aurata, L. ramada and Chelon labrosus were reared in small aquaria (50 L) of a recirculation system from the size of about 3.0 cm TL (50 fish per aquarium), using brackish (15 ppt) water and artificial high protein food. It was found that for a period of 80 days, growth performance was high at 23...
Presentation
Full-text available
Σε αυτή την παρουσίαση προσπάθησα να συμπεριλάβω όλους τους τρόπους αναπαραγωγής των φυκών (μονοκύτταρων, πολυκύτταρων, αποικιακών) διότι έλειπε ένα παρόμοιο βοήθημα για τους φοιτητές στο πεδίο αυτό.
Technical Report
Full-text available
The Messolonghi salterns were for me a natural laboratory or to put it another way, an exhibition of hidden microscopic life. Life in its extreme is not met only at the hot springs or at the glaciers zone but also in the waters of far more easier accessible places like the hypersaline waters of the salterns. It is well known, although not proven in...
Article
Full-text available
In a laboratory study 6 microalgae species were tested as food for the extremely halotolerant ciliate Fabrea salina in salinity of 35 ppt. Rhodomonas salina was found to be the best food in terms of specific growth rate and generation time followed by Dunaliella salina and Asteromonas gracilis. Isochrysis galbana, Chlorella sp and Tetraselmis sp we...
Technical Report
Full-text available
It was some years before when I was for the first time fascinated by the most prominent ciliate protozoan swarming the extremely saline waters sampled from the Messolonghi evaporation ponds of the local salt-works. This prominent ciliate is Fabrea salina and since then I kept it constantly in my laboratory exposing it to various experimental trials...
Technical Report
Full-text available
Οταν χρησιμοποιείται ο όρος φύκη το μυαλό μας πηγαίνει ασυναίσθητα σε νοητική σύλληψη μιας εικόνας των φυκιών που συναντάμε στη θάλασσα, δηλαδή μακροφυκών εύκολα διακρινόμενων μακροσκοπικώς. Ομως τόσο στη θάλασσα όσο και στις λίμνες η συντριπτική πλειονότητα των υπαρχόντων φυκών αποτελείται από μικροφύκη ή αλλιώς φυτοπλαγκτόν. Τα μικροφύκη πάλι για...
Technical Report
Full-text available
Dunaliella, το θαυμαστό φύκος των αλυκών Γεώργιος Ν. Χώτος, καθηγητής Εργαστήριο καλλιέργειας πλαγκτού, Τμ. Ζωϊκής παραγωγής, Αλιείας & Υδατοκαλλιεργειών, Πανεπιστήμιο Πατρών ghotos@teimes.gr Μετά από αρκετά χρόνια ενασχόλησης με το φυτοπλαγκτονικό "είδος" Dunaliella (μεταξύ άλλων) που διατηρώ και καλλιεργώ στο εργαστήριο καλλιέργειας πλαγκτού, κυ...
Technical Report
Full-text available
Κάθε οργανισμός για να διατηρηθεί χρειάζεται ενέργεια. Πρέπει να αποκτά ενέργεια συνεχώς για να μπορεί να επιτελεί κάθε φυσιολογική του δραστηριότητα. Εκτός από την ενέργεια χρειάζεται και περιοδικώς τροφοδοσία με χημικά μόρια τα οποία ως δομικά υλικά χρησιμοποιούνται για την αντικατάσταση των φθαρμένων μερών του, για τη δημιουργία καινούργιων (αύξ...
Technical Report
Full-text available
Σε κάθε απόπειρα να αναφερθούμε στα έμβια όντα, σε οποιοδήποτε τομέα των βιολογικών επιστημών και αν εντρυφήσουμε, πάντοτε θα περιφερόμαστε «γύρω», και θα οδηγούμαστε «προς», τον κεντρικό πυρήνα της ζωής, τι υπήρχε πριν, πως εξελίχθηκε και τι συμβαίνει τώρα. Κάθε τι που εξετάζουμε και είναι ζωντανό απαιτεί νοητική σύλληψη του τι σημαίνει ζωή και πο...
Conference Paper
In order to test its ability to be cultured in normal seawater , the extremely halotolerant ciliate Fabrea salina was fed with the microalgae Dunaliella salina, Asteromonas gracilis, Rhodomonas salina, Tetraselmis sp., Isochrysis galbana and Nannochloropsis sp. The best results in terms of growth rate and generation time were found for Fabrea fed R...
Technical Report
Full-text available
26.000 είδη φυκών περί τα 350 παράγουν τοξίνες. Τα μικροφύκη αυτά ανήκουν και στο προκαρυωτικό υπερβασίλειο (κυανοβακτήρια) και στο ευκαρυωτικό (η πλειονότητα των μικροφυκών). Η δράση των τοξινών που παράγονται από τα τοξικά μικροφύκη απασχολεί ολοένα και περισσότερο τους επιστήμονες και τους οργανισμούς προστασίας της υγείας των πολιτών επειδή η δ...
Conference Paper
During a survey in 2015 an impressive assemblage of organisms were found in the hypersaline ponds of the Messolonghi saltworks. The salinity ranged between 50 and 210 ppt and the organisms recorded fell in the categories of Cyanobacteria (22 species), Chlorophytes (5 species), Dinoflagellates (1 species), Protozoa (51 species), Diatoms (27 species)...
Conference Paper
Full-text available
Production of salt from seawater involves the selective recovery of pure NaCl, free of other soluble or non-soluble salts and other substances. To this end, condensation of seawater through solar evaporation results in the fractional crystallization of all contained salts; a process based on their varying solubility in seawater. Current, industrial...
Presentation
Full-text available
This is my presentation in the 10th World Salt Symposium at Park city Utah USA 19-21 June 2018, concerning the biota in the hypersaline ponds of Messolonghi saltworks (Greece).
Presentation
Full-text available
Η απόκτηση ανόργανου άνθρακα από τα φύκη δεν είναι μια απλή διαδικασία. Σε αυτή την παρουσίαση προσπάθησα να καλύψω συνοπτικώς μεν αλλά χωρίς εκπτώσεις παράλειψης των ουσιαστικών μηχανισμών την όλη διαδικασία.
Conference Paper
Full-text available
The halotolerant green alga Asteromonas gracilis isolated from the hypersaline saltern ponds of Messolonghi, Greece, was kept in indoor cultures and used for feeding rotifers, protozoa, copepods and Artemia sp. In all feeding trials all filter feeders accepted A. gracilis and grew. Additionally as of its morphology, movement and culture reliability...
Conference Paper
Full-text available
The effect of three different temperatures on the survival rate and growth of the Palaemonid juvenile prawn Palaemon adspersus in captivity was investigated. Three experimental temperatures were selected in order to investigate which is the best temperature for the future farming of the species. The prawns were collected from their natural habitat...
Technical Report
Full-text available
Στο πόνημα αυτό αναλύεται η παραγωγή ζωντανής τροφής (live food) όπως γίνεται στους ιχθυογεννητικούς σταθμούς των θαλασσινών ψαριών. Φυσικά πρόκειται για καλλιέργεια πλαγκτονικών οργανισμών (φυτοπλαγκτού και ζωοπλαγκτού). Αναλύονται βιολογικά και τεχνικά στοιχεία χαρακτηριστικών ειδών φυτοπλαγκτού, του τροχόζωου Brachionus plicatilis και της αλμυρο...
Working Paper
Full-text available
Σε αυτή την έκδοση του Φορέα Διαχείρισης Λιμνοθάλασσας Μεσολογγίου-Αιτωλικού παρουσιάζω με εκλαϊκευμένο αλλά και χωρίς επιστημονική έκπτωση ένα συνοπτικό πανόραμα από τη μικροσκοπική υδρόβια ζωή στις λεκάνες των αλυκών Μεσολογγίου.
Technical Report
Full-text available
Ως καλλιέργεια πλαγκτού νοείται η διαδικασία εκείνη η οποία με κατάλληλες ενέργειες του ανθρώπου και χρησιμοποιώντας ποικίλης φύσεως μέσα καταλήγει στην παραγωγή μεγάλης και διαχειρίσιμης μάζας φυτοπλαγκτονικών ή ζωοπλαγκτονικών οργανισμών. Σε σχέση με την ιχθυοκαλλιέργεια, η πλαγκτονική καλλιέργεια αποτελεί τον πρώτο κρίκο μιας επίπονης διαδικασία...
Technical Report
Full-text available
Σε αυτό το πόνημα αναλύονται και εξηγούνται όλες οι θεμελιώδεις αρχές της εντατικής ιχθυοκαλλιέργειας με ανακυκλούμενο νερό (κλειστά συστήματα). Καλύπτει ένα κενό στη βιβλιογραφία και επιχείρησα με κατανοητό τρόπο να εξηγήσω βιολογικές και μηχανικές διεργασίες που εμπλέκονται σε ένα τέτοιο εγχείρημα.
Article
Full-text available
Marine biofouling is a natural phenomenon representing one of the greatest problems in marine technology (navigation, aquaculture nets, etc). To circumvent these problems, antifouling paints or coatings, i.e. matrices containing biocidal species, are used to protect the submerged surfaces and objects. Polymers containing quaternary phosphonium or q...
Article
Full-text available
Hydrogels are three-dimensional, hydrophilic, polymeric networks composed of homopolymers or copolymers and are insoluble in water due to the presence of chemical or physical cross-links. When hydrogels come in contact with aqueous solutions, they can effectively sorb and retain the dissolved substances, depending on the nature of the monomeric uni...
Conference Paper
Full-text available
The deposition of microorganisms occurs continuously and dynamically to all surfaces submerged in seawater. This phenomenon is called bioaccumulation (biofouling). Marine biofouling represents one of the greatest problems in marine technology. To circumvent this problem, antifouling paints or coatings, i.e. matrices containing biocidal species, are...
Article
Full-text available
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...
Article
Full-text available
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...
Data
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...
Article
Full-text available
The development of Argyrosomus regius early development stages (embryonic, yolk sac and newly larval) was studied, with emphasis on yolk and lipid absorption. The effect of a progressively delayed initial feeding on the feeding ability and survival of this species was also examined. The number of days from hatching after which the feeding rate drop...
Data
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...
Data
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...
Conference Paper
Full-text available
The present work studies the morphometric characteristics of three freshwater fishes (Cyprinus caprio, Rutilus panosi, Scardinius acarnanicus) and the euryhaline fish Liza ramada caught in Messolonghi lagoon. The majority of the body parts of C. caprio and R. panosi presented an isometry with the total length. In contrast to this, almost all the ch...
Conference Paper
Full-text available
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...
Conference Paper
Full-text available
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...
Article
Full-text available
Background. The fisheries of the Greek lagoons is based on the seasonal fish migration from coastal areas to the lagoon and the summer-to-winter offshore fish migration. The knowledge of the age and growth of the species in the two connected regions is essential for the proper management of the resources. The aim of this study was to estimate the a...
Conference Paper
Full-text available
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...
Conference Paper
Full-text available
Study of the fish fauna living in canals which are discharging into the Mesolonghi lagoon The present work studies the structure, the seasonal distribution, some biological elements (age, growth, reproduction) of the fish population of two drainage canals which discharge into the Mesolonghi lagoon. In addition to this, the ecological relationships...
Technical Report
Full-text available
Το παρόν κείμενο αφορά στην ΤΕΛΙΚΗ έκθεση του έργου: «Μελέτη υφισταμένης κατάστασης ιχθυοπανίδας του συγκροτήματος των φραγμαλιμνών του κάτω ρου του ποταμού Αχελώου και κατάντη αυτού» το οποίο χρηματοδοτείται από την ΔΕΗ Α.Ε., ΔΕΥ/Συγκρότημα Αχελώου και υλοποιείται από το τμήμα Υδατοκαλλιεργειών και Αλιευτικής Διαχείρισης του Τ.Ε.Ι. Μεσολογγίου δια...
Conference Paper
Full-text available
One of the most popular tropical fish kept in the aquariums is the Angelfish. Angelfish belongs to the Cichlidae family and especially the species Pterophyllum scalare were found in the Amazone river and in the coastal rivers of Guinea. It distinguishes itself from other tropical species by its breeding behavior which involves competition for terri...
Conference Paper
Full-text available
Farming ornamental fish in aquariums and especially the tropical egg-layer with parental care is now an establish industry in several countries including Europe. The success of farming ornamental fish depends on their fish nutrition and the composition and type of the fish diets. This paper examines the growth rate and survival rate of cichlid Arch...
Conference Paper
Full-text available
Breeding ornamental tropical fishes is a unique experience that in majority abuts in the problems of feeding. Aquarist often overlooks the importance of feeding of a balanced diet for fish health and maintenance of water quality in the aquarium. Most hobbyists apply techniques which based on their experience or in the on-package feeding guide, with...
Technical Report
Full-text available
Η παρούσα προμελέτη σκοπεύει να αναλύσει το θέμα της δημιουργίας δημόσιου ενυδρείου στο Δήμο Μενιδίου Αιτωλοακαρνανίας. Ο Δήμος Μενιδίου είναι παράλιος στο Ανατολικό μέρος του Αμβρακικού κόλπου και χαρακτηρίζεται από φυσικό ανάγλυφο με όμορφη ακτογραμμή. Είναι δήμος διαμέσου του οποίου και κατά το μεγαλύτερο μήκος του, διασχίζεται από την εθνική οδ...
Article
Full-text available
Skinned, vacuum-packed, postrigor gilthead sea bream fillets were frozen individually with characteristic freezing times of 2, 18, 74 and 640 min (times to cool the thermal center of the fillets from -1 to -7C). Immediately after freezing, the fillets were thawed, and their quality was evaluated with tests related to muscle integrity, myofibrillar...
Conference Paper
Full-text available
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:...
Article
Full-text available
Variation in eight morphometric characteristics of the fry of four grey mullets species (Liza aurata, Liza saliens, Chelon labrosus and Mugil cephalus, Pisces: Mugilidae), all within the total length class of 20-35 mm (the grey mullets fry in this class size are the target of aquaculturists for stocking), in western Greece, was examined by using mu...
Conference Paper
Full-text available
A study was made on the nitrification process (conditioning) of filter bed in aquaria at temperatures of 5, 20, 25 and 30 o C. The filter media consisted of porous grains (lava) of 0,65-0,87 mm mean diameter. NH 4 Cl was used as the nitrogen source. The conditioning of the filter bed, was accomplished after 79, 47, 40 and 31 days, for the temperatu...
Conference Paper
Full-text available
A study was made on the nitrification process (conditioning) of filter bed in aquaria at temperatures of 5, 20, 25 and 30 o C. The filter media consisted of porous grains (lava) of 0,65-0,87 mm mean diameter. NH 4 Cl was used as the nitrogen source. The conditioning of the filter bed, was accomplished after 79, 47, 40 and 31 days, for the temperatu...
Article
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The rotifer Brachionus plicatilis was fed in experimental conditions with a small celled (2–5 μm) Chlorella sp. and a large celled (16–22 μm) Asteromonas gracilis algae. The specific growth rate (SGR) of rotifers fed Asteromonas (maximum 0.79) was statistically higher than that for rotifers fed Chlorella (maximium 0.61). The filtration and ingestio...
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SummaryA detailed study was made of the scales on the golden grey mullet Liza aurata in the lagoon of Messolonghi (W. Greece), in order to examine the suitability of scales for ageing. From a total of 1048 specimens of 9–59 cm total length (TL), the estimated ages ranged from 0+ to 8+ years, with only females at ages 7+ and 8+. The scale reading wa...
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This study examines the impact of environmental lighting and microalgae centrifugation on the nutrition of the rotifer B. plicatilis. Relatively high reproductive rates were found in the dark (compared to the light), when they were fed with centrifuged cells (compared to cells in levitation) of Dunaliella sp.(compared to Asteromonas gracilis and Te...
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The experimental studies on the impact of temperature on the growth rate of the big (18-25 μm), wall-less, halotolerant microalga Asteromonas gracilis, revealed that the optimum temperature for the mass culture of Asteromonas gracilis is 20 oC. Above 25 oC the culture deteriorates. The same was found for Tetraselmis sp.
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All five species of the Mugilidae fry (Mugil cephalus, Chelon labrosus, Liza aurata, Liza ramada, Liza saliens) were surveyed and caught by beach seine in the broader area of the Messolonghi-Etoliko lagoonal complex. Each species had its own peak of arrival in the coast. Conclusions can be drawn from this study about the best season for collection...
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Klisova is a typical shallow lagoon of Eastern Mediterranean, which is subjected to many human activities such as a city's refuse dump and the discharge of sewage treatment plant. In this work we present data on total and 75% HCl-extractable metal concentrations in order to detect the interrelations of the metals in a lagoon environment and to iden...
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The ability for food selectivity of rotifer Brachionus plicatiliswas studied in the laboratory by feeding mixtures of microalgae with various cell volumes. Chlorella sp. (≈22 µm3) was the reference algal species, and Asteromonas gracilis, (Chlorophyta) (≈2150 µm3), Tetraselmis suesica (≈268 µm3), Dunaliella salina (≈52 µm3) and Chaetoceros sp. (≈15...
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A study was made of the reproductive biology of Liza aurata (Pisces Mugilidae) from a local population in the lagoon of Klisova (Messolonghi, W. Greece), which revealed fundamental information about reproduction dynamics of this species. Gonadosomatic Index (GSI%) values were highest in September for both sexes and maintained this level from August...
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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...
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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...
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In a local population of Liza aurata in the lagoon of klisova (Messolonghi, W. Greece) the Gonadosomatic Index (GSI%) exhibited greatest values in September and kept high from August till November. Thus, spawning period extends through these months in the sea as all riping fish leave the lagoon in a seaward migration. First maturation occurred at a...
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Experimental studies on the effect of the use of the big (18-25μ) wall-less halotolerant microalgae Asteromonas gracilis as food for the rotifer Brachionus plicatilis compared with the one of Chlorella sp. on the specific growth rate, filrtration and injestion rate, revealed a much higher level of all these rates in favour of Asteromonas. The resul...
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Heavy metal concentrations (Fe, Al, Mn, Ni, Co, Cr, Cu, Zn) have been determined on 20 surficial and subsurficial sediments from the Klisova lagoon (Messolonghi, W. Greece). Metal concentrations generally were enriched, except for Fe, in the surficial sediments. Elemental concentrations and Igeo-values, for Ni, Co, Mn and Cr, were slightly higher i...
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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...