Muscle activity as a key indicator of welfare in farmed European sea bass (Dicentrarchus labrax L. 1758)

Groups of adult sea bass were reared at either low (10 kg m−3) or high (50 kg m−3) stocking densities respectively for 84 and 116 days. To monitor the red muscle activity, about 20 fish from both densities were surgically implanted with EMG (Electromyograms) radio transmitters, after EMG calibration during exhaustive swimming exercise (Ucrit test). Blood samples and morphometric measurements were also taken. EMG showed that the muscle activity of fish reared at 50 kg m−3 was on average twofold higher than fish kept at lower density. Cortisol was significantly more elevated at higher density and haemoglobin, haematocrit and RBCC (red blood cells count) showed the same trend, while lysozyme decreased. Patterns for glucose and lactate were less clear. The results showed that the contemporary use of functional (EMG) and physiological (haematological and biochemical) profiles could give a more comprehensive view of the fish status validating the diagnosis of fish stress induced by culture practices

Calibrating accelerometer data, as a promising tool for health and welfare monitoring in aquaculture: Case study in European sea bass (Dicentrarchus labrax) in conventional or organic aquaculture

Both the conventional and organic aquaculture sectors have grown rapidly over the past few years. Moreover, welfare has attracted increased attention on the part of both consumers and governments. However, fish welfare assessment is complex and thus needs to adapt measurements that are easily applicable to aquaculture conditions. In this study, in addition to classical welfare indicator measurements (physiological stress indicators and growth performance), we recorded the swimming activity data using acoustic transmitters to evaluate the welfare of European sea bass (Dicentrarchus labrax) fed a conventional vs. an organic diet. Prior feeding trial, the swimming activity recorded by tag has been calibrated with water speed during critical swimming speed (Ucrit) tests. This calibration allowed us to increase the power of the recorded data, providing information on swimming activity with respect to the Ucrit value and on the metabolic cost of swimming. After a four-month experimental period, physiological stress indicators and growth performance did not differ significantly between the two diet groups. However, we observed a subtle difference in swimming activity: the fish in the organic diet group were more active during the feeding period in the morning. All indicators considered, our results suggest that an organic diet does not incur higher metabolic costs and does not affect the welfare of the European sea bass. Moreover, this study shows that the use of acoustic transmitters previously calibrated with physiological indicators, such as Ucrit, is a promising tool for welfare monitoring in aquaculture conditions

Nazočnost vrsta iz porodice četverozupki (Tetraodontidae) u središnjem Sredozemlju: novi podaci iz južnog Jadrana

This paper presents the first record of the Lessepsian migrant fish Lagocephalus sceleratus (silver-cheeked toadfish) on the Italian side of the south Adriatic Sea. In addition, four specimens of Sphoeroides pachygaster (blunthead puffer) were analysed. Meristic and morphometric data of the silver-cheeked toadfish and blunthead puffer are in accordance with data from the Mediterranean. The specimen of silver-cheeked toadfish was a female with gonad in resting stage and the specimens of blunthead puffer were adults (male and female) with gonads in maturing, mature/spawner and post-spawning stage. The stomach contents of the specimen of silver-cheeked toadfish were composed by Mollusca Opistobranchia and Crustacea Brachyura. Stomach contents analysis of S. pachygaster confirmed that Mollusca are the preferred prey for this species. However, the presence of Crustacea (shrimps, crabs) and fish in the stomachs indicates that the blunthead puffer has a broad and variable diet in the south Adriatic Sea. The present study suggests the presence of an established population of blunthead puffer on the continental shelf of the southeast Adriatic Sea.U radu je predstavljen prvi nalaz lesepsijske migratorne vrste Lagocephalus sceleratus (srebrenopruga napuhača) na talijanskoj strani južnog Jadrana. Uz to, analizirana su i četiri primjerka vrste Sphoeroides pachygaster (napuhača). Meristički i morfometrijski podaci dobiveni analizom primjeraka ovih dviju vrsta su u suglasnosti sa postojećim podacima iz Sredozemlja. Analizirana jedinka srebrenopruge napuhače bila je ženka, s gonadama u stadiju mirovanja, dok su jedinke napuhače bile u stadiju sazrijevanja, zrelom stadiju i izmrještenom stadiju. Sadržaj želudaca srebrenopruge napuhače sastojao se od ostataka skupina Mollusca, Ophistobranchia i Crustacea Brachyura. Sadržaj želudaca jedinki vrste Sphoeroides pachygaster potvrdio je da ova vrsta u prehrani preferira mekušce (Mollusca) kao plijen. Ipak, nazočnost ostataka rakova i kozica (Crustacea) u njihovim želucima ukazuje na raznoliku prehranu ove vrste u južnom Jadranu. Ovo istraživanje ukazuje na postojanje formirane populacije vrste Sphoeroides pachygaster na kontinentalnom šelfu jugoistočne obale Jadranskog mora

Bio-Ecological Features Update on Eleven Rare Cartilaginous Fish in the Central-Western Mediterranean Sea as a Contribution for Their Conservation

Cartilaginous fish are commonly recognized as key species in marine ecosystems for their fundamental ecological role as top predators. Nevertheless, effective management plans for cartilagi- nous fish are still missing, due to the lack of knowledge on their abundance, distribution or even life-history. In this regard, this paper aims at providing new information on the life-history traits, such as age, maturity, reproductive period, in addition to diet characteristics of eleven rare cartilagi- nous fish inhabiting the Central-Western Mediterranean Sea belonging to the orders Chimaeriformes (Chimaera monstrosa), Hexanchiformes (Heptranchias perlo and Hexanchus griseus), Myliobatiformes (Aetomylaeus bovinus and Myliobatis aquila), Rajiformes (Dipturus nidarosiensis and Leucoraja circu- laris), Squaliformes (Centrophorus uyato, Dalatias licha and Oxynotus centrina) and Torpediniformes (Tetronarce nobiliana), useful for their assessment and for future management actions. Particularly, the present paper provides for the first time the age estimation of D. nidarosienis and L. circularis which were both found capable of becoming older than ten years. In addition, the present study updates the sizes of first maturity of C. uyato and D. licha, which appeared to be capable of reproducing earlier than what was previously hypothesized, representing very valuable information for a better understanding of these rare species populations status and, eventually, their conservation. On the basis of the stomach content analysis, it was possible to identify five different predator groups

Surgical implantation of electronic tags does not induce medium-term effect: insights from growth and stress physiological profile in two marine fish species

Abstract Background Telemetry applied to aquatic organisms has recently developed greatly. Physiological sensors have been increasingly used as tools for fish welfare monitoring. However, for the technology to be used as a reliable welfare indicator, it is important that the tagging procedure does not disrupt fish physiology, behaviour and performance. In this communication, we share our medium-term data on stress physiological profile and growth performance after surgical tag implantation in two important marine fish species for European aquaculture, the sea bream (Sparus aurata) and the European sea bass (Dicentrarchus labrax). Results Blood samples after surgical tag implantation (46 days for the sea bream and 95 days for the sea bass) revealed no differences between tagged and untagged fish in cortisol, glucose and lactate levels, suggesting that the tag implantation does not induce prolonged stress in these species. Moreover, the specific growth rates were similar in the tagged and untagged fish of both species. Conclusion Surgical tag implantation does not have medium-term consequences for the stress physiology and growth performance of these two marine fish species in a controlled environment. These observations support the use of accelerometer tags as valuable tools for welfare monitoring in aquaculture conditions. This study also shows that tagged fish can be sampled during experiments and considered a representative portion of the population, as they display growth and physiological parameters comparable to those of untagged fish

Molecular determinants for the activating/blocking actions of the 2H-1,4-benzoxazine derivatives, a class of potassium channel modulators targeting the skeletal muscle KATP channels

The 2H-1,4-benzoxazine derivatives are modulators of the skeletal muscle ATP-sensitive-K+ channels (KATP), activating it in the presence of ATP but inhibiting it in the absence of nucleotide. To investigate the molecular determinants for the activating/blocking actions of these compounds, novel molecules with different alkyl or aryl-alkyl substitutes at position 2 of the 1,4-benzoxazine ring were prepared. The effects of the lengthening of the alkyl chain and of branched substitutes, as well as of the introduction of aliphatic/aromatic rings on the activity of the molecules, were investigated on the skeletal muscle KATP channels of the rat, in excised-patch experiments, in the presence or absence of internal ATP (10 -4 M). In the presence of ATP, the 2-n-hexyl analog was the most potent activator (DE50 = 1.08 × 10-10 M), whereas the 2-phenylethyl was not effective. The rank order of efficacy of the openers was 2-n-hexyl ≥2-cyclohexylmethyl >2-isopropyl = 2-n-butyl = 2-phenyl ≥ 2-benzyl = 2-isobutyl analogs. In the absence of ATP, the 2-phenyl analog was the most potent inhibitor (IC50 = 2.5 × 10-11 M); the rank order of efficacy of the blockers was 2-phenyl ≥ 2-n-hexyl > 2-n-butyl > 2-cyclohexylmethyl, whereas the 2-phenylethyl, 2-benzyl, and 2-isobutyl 1,4-benzoxazine analogs were not effective; the 2-isopropyl analog activated the KATP channel even in the absence of nucleotide. Therefore, distinct molecular determinants for the activating or blocking actions for these compounds can be found. For example, the replacement of the linear with the branched alkyl substitutes at the position 2 of the 1,4-benzoxazine nucleus determines the molecular switch from blockers to openers. These compounds were 100-fold more potent and effective as openers than other KCO against the muscle KATP channels. Copyright © 2008 The American Society for Pharmacology and Experimental Therapeutics

Determinants of Noninvasive Ventilation Outcomes during an Episode of Acute Hypercapnic Respiratory Failure in Chronic Obstructive Pulmonary Disease: The Effects of Comorbidities and Causes of Respiratory Failure

Objectives. To investigate the effect of the cause of acute respiratory failure and the role of comorbidities both acute and chronic on the outcome of COPD patients admitted to Respiratory Intensive Care Unit (RICU) with acute respiratory failure and treated with NIV. Design. Observational prospective study. Patients and Methods. 176 COPD patients consecutively admitted to our RICU over a period of 3 years and treated with NIV were evaluated. In all patients demographic, clinical, and functional parameters were recorded including the cause of acute respiratory failure, SAPS II score, Charlson comorbidity index, and further comorbidities not listed in the Charlson index. NIV success was defined as clinical improvement leading to discharge to regular ward, while exitus or need for endotracheal intubation was considered failure. Results. NIV outcome was successful in 134 patients while 42 underwent failure. Univariate analysis showed significantly higher SAP II score, Charlson index, prevalence of pneumonia, and lower serum albumin level in the failure group. Multivariate analysis confirmed a significant predictive value for pneumonia and albumin. Conclusions. The most important determinants of NIV outcome in COPD patients are the presence of pneumonia and the level of serum albumin as an indicator of the patient nutritional status

Molecular Insights into the Local Anesthetic Receptor within Voltage-Gated Sodium Channels Using Hydroxylated Analogs of Mexiletine

We previously showed that the β-adrenoceptor modulators, clenbuterol and propranolol, directly blocked voltage-gated sodium channels, whereas salbutamol and nadolol did not (Desaphy et al., 2003), suggesting the presence of two hydroxyl groups on the aromatic moiety of the drugs as a molecular requisite for impeding sodium channel block. To verify such an hypothesis, we synthesized five new mexiletine analogs by adding one or two hydroxyl groups to the aryloxy moiety of the sodium channel blocker and tested these compounds on hNav1.4 channels expressed in HEK293 cells. Concentration–response relationships were constructed using 25-ms-long depolarizing pulses at −30 mV applied from an holding potential of −120 mV at 0.1 Hz (tonic block) and 10 Hz (use-dependent block) stimulation frequencies. The half-maximum inhibitory concentrations (IC50) were linearly correlated to drug lipophilicity: the less lipophilic the drug, minor was the block. The same compounds were also tested on F1586C and Y1593C hNav1.4 channel mutants, to gain further information on the molecular interactions of mexiletine with its receptor within the sodium channel pore. In particular, replacement of Phe1586 and Tyr1593 by non-aromatic cysteine residues may help in the understanding of the role of π–π or π–cation interactions in mexiletine binding. Alteration of tonic block suggests that the aryloxy moiety of mexiletine may interact either directly or indirectly with Phe1586 in the closed sodium channel to produce low-affinity binding block, and that this interaction depends on the electrostatic potential of the drug aromatic tail. Alteration of use-dependent block suggests that addition of hydroxyl groups to the aryloxy moiety may modify high-affinity binding of the drug amine terminal to Phe1586 through cooperativity between the two pharmacophores, this effect being mainly related to drug lipophilicity. Mutation of Tyr1593 further impaired such cooperativity. In conclusion, these results confirm our former hypothesis by showing that the presence of hydroxyl groups to the aryloxy moiety of mexiletine greatly reduced sodium channel block, and provide molecular insights into the intimate interaction of local anesthetics with their receptor