Stefano Peruzzi

Verified

Stefano verified their affiliation via an institutional email.

Learn more

Verified

Stefano verified their affiliation via an institutional email.

Learn more

• BSc (Biology), PhD (Aquaculture & Fish genetics)
• Professor at UiT The Arctic University of Norway

Triploid Atlantic salmon (Salmo salar L.) is seen as one of the best solutions to solve key issues in the salmon farming industry, such as the impact of escapees on wild stocks and pre-harvest sexual maturation. However, the effects of triploidy on salmon smoltification are poorly understood at the molecular level, even though smoltification is a v...

Simple Summary Activation of immune cells is bioenergetically expensive, requiring precise control of cellular metabolism. This applies also to innate immune cells. The current study shows that the immunostimulants, Astragalus, Hyaluronic acid, Imiquimod, and Poly I:C can modulate the expression of genes involved in the innate antiviral immune, as...

Triploidy is induced in Atlantic salmon (Salmo salar) to produce sterile fish for genetic containment and to hinder early sexual maturation in farmed fish, but it can have unwanted negative effects on growth, health, and welfare. However, the growth and welfare of triploid fish may be improved by adjusting the rearing environment, feeding condition...

The genome size of organisms impacts their evolution and biology and is often assumed to be characteristic of a species. Here we present the first published estimates of genome size of the ecologically and economically important ectoparasite, Lepeophtheirus salmonis (Copepoda, Caligidae). Four independent L. salmonis genome assemblies of the North...

The use of recirculating aquaculture systems (RAS) for Atlantic salmon (Salmo salar) production has become increasingly common. RAS water disinfection plays a crucial role on its biosecurity. Peracetic acid (PAA) is a promising disinfectant due to its powerful oxidative properties, broad antimicrobial spectrum, and rapid degradation into no harmful...

The genome size of organisms impacts their evolution and biology and is often assumed to be characteristic of a species. Here we present the first published estimates of genome size of the ecologically and economically important ectoparasite, Lepeophtheirus salmonis (Copepoda, Caligidae). Four independent L. salmonis genome assemblies of the North...

Triploid, sterile Atlantic salmon (Salmo salar) could make a contribution to the development of the farming industry, but uncertainties about the performance and welfare of triploids have limited their adoption by farmers. In this study, we compared the ontogeny of digestive tract morphology and enzyme activities (pepsin, trypsin, chymotrypsin, alk...

In this study, we compared the liver transcriptome of diploid and triploid salmon fed a standard fishmeal commercial diet from fry stage to the completion of parr-smolt transformation.

Mean lengths of newly hatched cod larvae from egg incubation at 4 °C (Low-L) and 9.5 °C (High-H) were similar, and only minor differences were observed in larval histomorphology. However, growth performance of larvae reared at 4 °C (T1-LL) and 9.5 °C (T2-LH) from the 4 °C egg incubation and 4 °C (T3-HL) and 9.5 °C (T4-HH) from the 9.5 °C incubation...

Diploid and triploid Atlantic salmon, Salmo salar were fed high-protein, phosphorus-rich diets (56–60% protein; ca 18g phosphorus kg⁻¹ diet) whilst being reared at low temperature from start-feeding until parr-smolt transformation. Performances of salmon fed diets based on fish meal (STD) or a mix of fishmeal and hydrolysed fish proteins (HFM) as t...

Fish growth. Body weight, length and condition factor (K factor) of diploid (2n) and triploid (3n) Atlantic salmon, Salmo salar, fed a fish meal (STD) diet and a diet containing high proportions of hydrolyzed fish protein (HFM) at ten sampling points in the period 95–2745 degree-days post start-feeding (ddPSF). Different superscript letters denote...

Fish deformities. Vertebral numbers, skeletal deformities and abnormalities of diploid (2n) and triploid (3n) Atlantic salmon, Salmo salar, fed a fish meal (STD) diet and a diet containing high proportions of hydrolyzed fish protein (HFM) at parr (1390 ddPSF) and smolt (2745 ddPSF) stage. Different superscript letters denote significant differences...

Background Fully isogenic lines in fish can be developed using “mitotic” gynogenesis (suppression of first zygotic mitosis following inactivation of the sperm genome). However, genome-wide verification of the steps in this process has seldom been applied. We used ddRADseq to generate SNP markers in a meiotic gynogenetic family of European seabass (...

This study has investigated the muscle growth of diploid and triploid Atlantic cod (Gadus morhua) juveniles raised in replicate tanks over a period of 29 weeks and analysed at three sampling points (February, June and September). Data for weight, length, condition factor (K), muscle fibre growth and myogenic progenitor cells (MPCs) number were coll...

Triploid fish may differ from diploids in a number of morphological and physiological characteristics. The present study was undertaken to examine the effects of ploidy on the gut morphology of Atlantic salmon post-smolts (Salmo salar L.). For this purpose, we compared the intestinal length (relative gut length, RGL), pyloric caeca number and mass...

The aim of this study was to compare somatic growth and muscle fibre development in diploid and triploid siblings of Atlantic cod (Gadus morhua Linnaeus, 1758) during the larval stage. Newly hatched larvae were transferred into 200-L tanks, three tanks per ploidy group (70 larvae L−1, continuous light, gradually increasing seawater temperature 7–11...

Androgenesis is a form of uniparental reproduction leading to progenies inheriting only the paternal set of chromosomes. It has been achieved with variable success in a number of freshwater species and can be attained by artificial fertilization of genetically inactivated eggs following exposure to gamma (γ), X-ray or UV irradiation (haploid androg...

Fish egg and larval development, growth and mortality are generally highly influenced by temperature as well as feed quality. The national cod-developmental project CODE (RCN-199482) was established in order to explain the mechanisms behind early life history success or failure. The present investigation aims at identifying possible developmental d...

The objective of this paper was to compare the growth and gut morphology of juvenile diploid and triploid Atlantic cod (Gadus morhua) reared under similar conditions. Individually tagged 36-week-old diploid (mean weight 49.3 ± 13.8 g) and triploid (mean weight 43.6 ± 11.2) juvenile cod were measured at intervals during a 29-week growth trial. Data...

Using sterile triploids can reduce environmental impacts of aquaculture, but the physiology of triploids and diploids differ and may therefore affect triploid performance. In this study, we investigated the recovery from exhaustive, anaerobic exercise in diploid and triploid Atlantic cod (Gadus morhua). Cod swam to exhaustion in a large swim tunn...

In Norway, during the establishment phase of the Atlantic cod (G. morhua) farming industry (2000-2008), several biological as well as financial bottlenecks affected its development, profitability and sustainability. The major pitfalls were Fish juveniles’ quality, strengthening of wild cod population with increased landings and resulting price fall...

Replicated adaptive radiation events, typified by phenotypic divergence across resource axes, provide important insight into the eco-evolutionary dynamics that lead to the formation of new species. Here we show that in trimorphic adaptive radiations of European whitefish (Coregonus lavaretus) divergence of the physiological oxygen transport system...

Understanding how a monophyletic lineage of a species diverges into several adaptive forms has received increased attention in recent years, but the underlying mechanisms in this process are still under debate. Postglacial fishes are excellent model organisms for exploring this process, especially the initial stages of ecological speciation, as pos...

Little is known about the functional consequences of triploidy in Atlantic cod. In this work, we compared the gut morphology of diploid and triploid offspring of wild and selected broodstock. Three-year-old triploid offspring of wild cod (mean weight 1695±346g) had approximately 18% fewer pyloric caeca (125±9 vs.172±14, P<0.001) and a 23% shorter i...

Androgenesis has been achieved with variable success in a number of fish species including Nile tilapia (Oreochromis niloticus), zebrafish (Danio rerio), common carp (Cyprinus carpio), and rainbow trout (Oncorhynchus mykiss) as reviewed by Komen and Thorgaard (2007). Androgenesis is a form of uniparental reproduction leading to progenies inheriting...

We carried out an experiment to determine how rapidly the early incubation temperature of Atlantic cod eggs can be increased without affecting normal embryonic development and hatching. Atlantic cod eggs were incubated at a constant low temperature (4.5 ± 0.5°C; T5 – control) and four temperature increment treatments where the temperatures were inc...

The aim of this study was to compare somatic growth and muscle fibre development in diploid and triploid siblings of Atlantic cod (Gadus morhua Linnaeus, 1758) during the larval stage. Newly hatched larvae were transferred into 200 L tanks, three tanks per ploidy group (70 larvae L-1 , continuous light, gradually increasing seawater temperature 7-1...

In North America, populations of lake whitefish (Coregonus clupeaformis) have evolved sympatric 'dwarf' and 'normal' ecotypes that are associated with distinct trophic niches within lakes. Trophic specialization should place diverging physiological demands on individuals, and thus, genes and phenotypes associated with energy production represent id...

The production of sterile triploid fish may be a viable option to tackle the problems of precocious sexual maturation and the genetic impact of farmed fish escapees in cod farming. This could meet both industrial and environmental criteria. In this work, the effects of triploidy on growth, body traits, muscle fibre distribution, and fillet quality...

Gynogenesis is one of several chromosome-manipulating techniques used in fish. In gynogenesis the male does not contribute to the genetic material of the offspring, and the sperm cells act only as stimulators in order for the egg to start development. This technique has several applications, both in aquaculture and in biological research: gynogenet...

Abstract The aim of this study was to investigate the effect of natural zooplankton versus rotifers and the effect of prey size on the growth and survival of cod larvae. At 20 days post hatch (DPH) myotome height, standard length and dry mass were significantly higher in larvae fed zooplankton compared to those fed rotifers. The dry mass at age 25...

The growth potential of cod larvae is not fully achieved when rotifers (Brachionus spp.) are used as live feed. In this experiment, we studied the effect of natural zooplankton (mainly copepods) on the growth of cod (Gadus morhua L.) larvae reared in intensive systems. Using a growth model developed for cod larvae, the growth rates observed could b...

A method of geometric morphometrics was used to characterize body shape variation in meiotic gynogenetic and triploid sea bass in comparison with diploid controls. A total of 13 coordinate landmark data were recorded on the profile of 34-month-old control (n = 81), gynogenetic (n = 117) and triploid (n = 131) siblings generated from two females (A...

A method of geometric morphometrics was used to characterize body shape variation in meiotic gynogenetic and triploid sea bass in comparison with diploid controls. A total of 13 coordinate landmark data were recorded on the profile of 34-month-old control (n = 81), gynogenetic (n = 117) and triploid (n = 131) siblings generated from two females (A...

This book contains 27 chapters on finfish aquaculture. The chapters were designated into four main topics: I. Aquaculture diversification an introduction (contains the first seven chapters namely: fish culture: achievements and challenges, fish culture: the rearing environment, fish culture: feeds and feeding, farmed species and their characteristi...

This book contains 27 chapters on finfish aquaculture. The chapters were designated into four main topics: I. Aquaculture diversification an introduction (contains the first seven chapters namely: fish culture: achievements and challenges, fish culture: the rearing environment, fish culture: feeds and feeding, farmed species and their characteristi...

The work compares the characteristics of milt produced by diploid and triploid Atlantic cod in terms of sperm motility, density, DNA content, seminal-fluid composition and the ability of sperm to fertilize the eggs. The mean track velocity (VCL) was higher in the sperm of diploid than in the triploid males at 20 s post-activation (p.a.; 124.04 ± 6....

Atlantic cod (Gadus morhua L.) is a new species in aquaculture and its responsiveness to aquaculture conditions is under investigation. High responsiveness to stress may be disadvantageous for traits of economic importance, such as growth, disease resistance and reproductive performance. The objectives of this study were a) to investigate the varia...

The effects of thermal treatments on induction of triploidy in Atlantic cod have been investigated. Cold shock [−1.7±0.1°C at 20 min post fertilization (PF) for 2 h] was based on a previously developed protocol, and heat shocks, below the lethal threshold of 24°C, were at 16, 18 or 20°C applied 20, 30 or 40 min PF for 20 min. Cold shock did not aff...

Although the actiology of swimbladder inflation anomalies in important aquaculture species such as European sea bass D. labrax is not fully determined, culture conditions are commonly suggested as main contributory factors. Little information is available on whether swimbladder inflation has a genetic basis for its expression too. In this work, 24...

Fertilization of tilapia (Oreochromis niloticus) eggs with heterologous sperm from carp (Cyprinus carpio), and from some other eyprinids resulted in higher levels of haploid gynogenetic development than in unfertilized eggs. Normal and irradiated carp sperm achieved similar rates of activation of tilapia eggs, but lower rates than those achieved by...

The purpose of this study was to determine whether diploid and triploid sea bass differed in terms of main haematological and physiological characteristics. Diploid and triploid fish were produced by sub-optimal pressure treatments and held in communal environments under standard rearing conditions. Total red blood cell count (RBCC), haemoglobin co...

The objective of this study was to develop a rapid and effective method of sexing juvenile sea bass with minimum labour and material. For this aim, the gonad squash mount technique was applied along with macroscopic techniques for sexing a large number of experimental fish at the age of 215-275 days post fertilisation (p.f.). At this age, 90% of th...

The nuclear DNA content in Dicentrarchus labrax, Sparus aurata, Liza ramada, and Anguilla anguilla, was measured by flow cytometric analysis. Male human leukocytes were used as internal reference cells. Nucleated fish erythrocytes were stained simultaneously to human leukocytes with a staining buffer containing propidium iodide (PI). Nuclear DNA co...

Meiotic gynogenetic and triploid sea bass were produced by pressure shocks according to a previously published protocol. Pressure-treated groups did not survive as well as controls during early development and larval rearing. Performances, sexual maturation and carcass quality were examined over a period of 34–45 months. At the age of 34 months, gr...

A preliminary study on tetraploid gynogenetic induction in the European sea bass was performed by pressure-blocking the second polar body release and the first cleavage in eggs fertilized with ultraviolet-irradiated sperm. Fertilization of eggs with genetically inactivated sperm produced only haploid development that terminated around hatching. Pre...

Tetraploidy, which is useful for the production of all-triploids, can be induced in marine bivalves by manipulating meiosis. In this study, we tested the effects of temperature on cytochalasin B (CB)-induced meiosis inhibition in a model bivalve, the dwarf surfclam, Mulinia lateralis Say. Newly fertilized eggs of the dwarf surfclam were treated wit...

The papers presented in this volume represent only a small part of the results obtained within the scope of the first integrated programme concerning the Mediterranean Sea. The latter is considered as a downscaled model of the ocean system, and a regional sea for the targeted projects supported by the European Commission.Whatever the domain is, the...

Tetraploidy, which is useful for the production of all-triploids, can be induced in marine bivalves by manipulating meiosis. In this study, we tested effects of temperature on cytochalasin B (CB)-induced meiosis inhibition in a model bivalve, the dwarf surf-clam, Mulinia lateralis (Say). Newly fertilized eggs of the dwarf surf-clam were treated wit...

The optimal conditions for the retention of the second polar body in sea bass eggs were investigated by altering the timing, intensity and duration of application of pressure and cold shocks. Treatment optima for cold shocks were 0–1°C for 15–20 min at 5 min after fertilisation (a.f.) and 8500 psi for 2 min at 6 min a.f. for pressure shocks. Meioge...

An investigation was undertaken to study the effect of the synthetic androgen 17α-methyldehydrotestosterone on the sex reversal and gonadal development of the European sea bass Dicentrarchus labrax L. A combination of three different hormonal doses (0.5, 3, 5 mg/kg food) and three treatment durations (30, 60, 90 days) was tested starting at 84 days...

Metaphase figures suitable for karyological investigations in fish were produced by the use of non-invasive and non-destructive methodologies. Large numbers of dividing scale epithelial cells were obtained by two methods: first, scale epithelia of Oreochromis niloticus were cultured for 22 hours at 28°C, and second, scale epithelia of Cyprinus carp...