Sharpsnout Seabream Research Articles

Host–parasite relationship of Ceratomyxa puntazzi n. sp. (Myxozoa: Myxosporea) and sharpsnout seabream Diplodus puntazzo (Walbaum, 1792) from the Mediterranean with first data on ceratomyxid host specificity in sparids

Sparidae are economically important fishes to both, fisheries and aquaculture in the Mediterranean. Species diversification is an important strategy for the development of Mediterranean aquaculture. One of the species recently introduced is the sharpsnout seabream Diplodus puntazzo (Walbaum, 1792). During a parasitological study of fish from the Gulf of Valencia and the Mar Menor (Spain), myxozoan spores belonging to the genus Ceratomyxa were found in the gall bladder of D. puntazzo. A morphological description of the spores, which includes histology and transmission electron microscopy (TEM) as well as molecular (SSU ribosomal DNA) data resulted in the erection of a new species, Ceratomyxa puntazzi n. sp. A histopathological study of C. puntazzi n. sp. infection in D. puntazzo showed that the parasite causes necrosis and loss of epithelial cells in the gall bladder, and provokes a pericholangitis in the liver tissue surrounding the bile ducts. Furthermore, molecular data obtained from C. puntazzi n. sp. and three other ceratomyxids from the closely related fish species Diplodus annularis L. and Sparus aurata L. which share the same habitat suggest that the genus Ceratomyxa is host-specific in sparids, which agrees with data previously obtained from Serranidae, Labridae and Pomacentridae, and that ceratomyxid species from sparids in the Mediterranean originated from a common ancestor.

Chronic ulcerative dermatopathy in cultured marine fishes. Comparative study in sharpsnout sea bream, Diplodus puntazzo (Walbaum)

Chronic ulcerative dermatopathy (CUD) also known as chronic erosive dermatopathy, hole-in-the-head, head and lateral line erosion syndrome (HLLE) and lateral line depigmentation (LLD) is a chronic disease of unknown aetiology that affects the lateral line canals of the head and the trunk of various fish species. It has been described only in freshwater species although there are reports that it also affects marine fish. Here, we describe the disease in cultured sharpsnout sea bream using histology and scanning electron microscopy and identify several marine species as CUD sensitive. The results of this study correlate the development of the disease with the use of borehole water, indicating that the aetiology is probably associated with water quality rather than nutritional imbalance or infectious agents.

Effect of masking organoleptic properties of fat on diet self-selection by the sparid Diplodus puntazzo

Fish are able to select a balanced diet according to their nutritional needs by choosing among incomplete feeds or even pure macronutrients. However, the relevance of both the organoleptic properties of diet and the postingestive signals that they produce remains unclear. Thus, sharpsnout seabream were allowed to select between diets containing different edible oils with their organoleptic properties masked by using gelatine capsules. Fish were fed capsules of two different colours so that they could associate the capsule colour with its corresponding postingestive effect. The longitudinal experiment included a first phase during which the fish were adapted to consuming the gelatine capsules. In a second phase, the fish were challenged with two different encapsulated diets: one comprising a complete diet containing fish oil and the other a fat-free diet. Sharpsnout seabream showed a preference for the fish oil capsules (3.8 ± 1.1 g kg−1 body weight (BW), 66.8% of total intake) over the fat-free capsules, showing that they were able to associate the colour of the capsule with their nutritional content through postingestive signals. After that, the fish were challenged to select between the capsules containing the fish oil diet and capsules containing a vegetable oil (linseed or soybean), in which case they showed no preference between diets (2.4 ± 0.3: 2.1 ± 0.5 g kg−1 BW of fish oil versus linseed oil capsules and 2.2 ± 0.2: 1.8 ± 0.6 g kg−1 BW of fish oil versus soybean oil capsules), indicating that the fatty acid composition of the different oils was not sufficient to affect dietary selection through postingestive signals. So, in conclusion, when orosensorial information from food is absent, the fish are able to select between diets at a macronutrient level by using postingestive information. However, this information is not sufficient for distinguishing between diets that differ in the type of oil used.

Comparative Ontogeny of the Digestive Tract in Sharpsnout Sea Bream Diplodus puntazzo Cetti and Common Pandora Pagellus erythrinus L

The ontogeny of the alimentary tract and its associated structures (liver, pancreas, gall bladder) was compared between sharpsnout sea bream Diplodus puntazzo and Pagellus erythrinus and some differences were highlighted. The first goblet cells appeared earlier in sharpsnout seabream (5-7 DAH) and later in common pandora (9-11 DAH), as well as taste buds which appeared at 11 DAH in sharpsnout seabream and at 17 DAH in common pandora. On the contrary, stomach segmentation in a cardiac, fundic and pyloric portions was more precocious in common pandora than in sharpsnout seabream, although gastric glands were formed almost simultaneously. Early caecal development was much more precocious in sharpsnout seabream (10 DAH) than in common pandora (22 DAH). At 3 DAH in sharpsnout seabream and later (10 DAH) in common pandora, primordial mucosal folding of intestine began, which appeared well developed in the anterior portion, by 22 DAH in common pandora and by 28 DAH in sharpsnout seabream. The functional meanings of these aspects were discussed comparatively.

Digestive Enzymes in Larvae and Juveniles of Farmed Sharpsnout Seabream (Diplodus puntazzo) (Cetti, 1777)

The ontogenetic development and pattern of main digestive enzyme activities (proteases, carbohydrases and lipases) were investigated in farmed sharpsnout seabream Diplodus puntazzo larvae and juveniles, during the passage from the larval stage to adult (from 21 to 277 days after hatching - DAH). Larvae showed exponential growth, thus confirming that Rotifers and Artemia nauplii are suitable preys for early feeding of D. puntazzo larvae. Pepsin activity was low in the larvae, but it increased afterwards in relation with stomach development. In juveniles, levels of specific activity of trypsin, chymotrypsin and elastase were lower compared to that recorded in larvae. A decrease in the activity of the alkaline proteases could be related to an increase in the functionality of stomach. Qualitative and quantitative assay of glycosidases (� -amylase, cellulase and maltase) showed high glycosidase activity, indicating that D. puntazzo is capable of digesting carbohydrates in its diet. Levels of lipase activity in juveniles were higher than those found in larvae. Our results didn't show an inductive character of lipases, since in juveniles the activity levels were almost constant even if the fat content of compound diet varied (from 7.0 % to 20 %). The rapid changes in the digestive activities of D. puntazzo larvae supported the existence of well established induction and regulation digestive mechanisms. Present results also confirm that D. puntazzo larvae have complete digestive enzymatic equipment that increased during larval ontogeny and enable larvae to digest and absorb nutrients contained in live preys once exogenous feeding occurred. The enzymatic pattern is correlated with omnivorous feeding habits of the species. Moreover, the patterns of activity of the main digestive enzymes of D. puntazzo larvae and juveniles indicated the early functional development of their digestive system and suggested this species as a good candidate for Mediterranean aquaculture using the compound diet.

Growth performance, histological alterations and fatty acid profile in muscle and liver of sharp snout sea bream (Diplodus puntazzo) with partial replacement of fish oil by pork fat

Four isonitrogenous (42% crude protein) and isolipidic (20%) diets were formulated using four different percentages of pork fat to substitute fish oil at 0, 25, 50 and 75% to evaluate the performance, body composition, fatty acids and liver histology of sharpsnout sea bream juveniles. One hundred and twenty fish (average weight 33.4 ± 2.9 g) were randomly distributed into pens (90 l capacity). Triplicate groups were fed each test diet twice a day to apparent satiation for 84 days. No difference was observed for feeding and growth performance. The only significant difference with respect to carcass was in moisture content (P < 0.05). With respect to liver fatty acids, there were significant differences in EPA and DHA, being fish fed 75% of pork fat that obtained the lowest value. With respect to muscle fatty acids, there were significant differences in saturated fatty acids and fish fed 0% of pork fat obtained the lowest value, but in poly unsaturated fatty acids the 75% of pork fat reported the lowest value. Although in both fish muscle and liver fatty acids, fish fed 75% pork fat diet presented significant difference in n-3 highly unsaturated fatty acids and n3/n6, but in LA fish fed the 0% of pork fat diet presented the lowest value in liver and in fish muscle not only the 0% but also the 25% of pork fat diet obtained the lowest value.

Effects of the partial substitution of fish meal by soy bean meal with or without mannanoligosaccharide and fructooligosaccharide on the growth and feed utilization of sharpsnout seabream, Diplodus puntazzo (Cetti, 1777): preliminary results

The present study was carried out in order to investigate the effects of the mannanoligosaccharide (MOS) and fructooligosaccharide (FOS) on sharpsnout seabream, Diplodus puntazzo in the context of partial fish meal substitution by soybean meal. One-hundred-forty-four sharpsnout seabream of about 100 g initial body weight were randomly divided in 12 experimental tanks (180 litre each). Testing conditions included 12 fish per tank, with triplicate tanks for treatment. The experimental period lasted 114 days. Average water temperature was 21.9±1.6°C, salinity was 30.0%0 and pH ranged from 7 to 8. Four isonitrogenousisolipidic diets were tested: a control diet (FM) with fish meal as the sole protein source; a second diet (SBM) with approximately 40% of the protein supplied by soybean meal. The remaining two diets were formulated adding 8g of MOS and FOS per kg of the SBM diet respectively. Average final weight, specific growth rate, feed conversion ratio and protein efficiency ratio remained unaffected by partial fish meal substitution and by MOS or FOS supplementation. Also apparent digestibility coefficients values for organic matter, protein, lipid and energy were not significantly affected by dietary treatment.

A study of partial replacement of fish meal with sunflower meal on growth, amino acid retention, and body composition of sharpsnout seabream, &lt;I&gt;Diplodus puntazzo&lt;/I&gt; (Actinopterygii: Perciformes: Sparidae)

Background. Our previous study demonstrated that sharpsnout seabream, Diplodus puntazzo (Walbaum, 1792),can be fed with up to 34.8% sunflower meal (SFM), with excellent results in growth parameters and feed efficiency.&nbsp; The aim of the current study was to test the replacement of fish meal with SFM in the diet formulation for sharpsnout seabreamand to evaluate growth, nutritive parameters, amino acid retention, and body composition of the fish during the fattening period. Materials and methods. Sixteen baskets (300 L capacity), each with thirteen fish, were distributed in a recirculated saltwater system to allow four experimental diets containing 40% crude protein (CP) and 20% crude lipid (CL) with 0%, 11.7%, 23.5%, and 34.8% SFM partially replacing fish meal to be used in quadruplicate for this experiment.&nbsp; The fish were fed these diets ad libitum during the experiment, which lasted for 162 days.&nbsp; Growth, nutrition efficiency, biometrics, carcass composition, amino acid composition, and amino acid retention of the experimental fish were evaluated. Results. There were no statistical differences in the growth parameters among the treatments.&nbsp; However, fish fed a diet containing 34.8% SFM had the lowest feed intake (FI), lowest feed conversion ratio (FCR), and the highest protein efficiency ratio (PER).&nbsp; There were also no statistical differences in the biometric parameters although fish fed the diet containing 10% SFM had the lowest CP levels.&nbsp; Leucine was the only difference in the essential amino acid (EEA) profile with fish fed a diet containing 11.7% SFM having the lowest levels of leucine.&nbsp; Although there were fluctuations among the amino acid retentions, they were not statistically significant. Conclusion. SFM (up to 34.8%) can be included in the diets of sharpsnout seabream, thereby, replacing 27% of the fish meal without altering the fish growth.&nbsp

Spermatozoa of Sharpsnout sea bream ( Diplodus puntazzo) and European sea bass ( Dicentrarchus labrax) express opioid receptors

Endogenous opioid peptides (EOP) are molecules affecting many biological functions influencing productive and reproductive performance. They increase in stress conditions and interact with specific opioidergic receptors (OR): delta, kappa and mu. Several studies in other animal species suggest that they can also affect sperm cell motility. In fish the ionic external environment modulates the increase of intracellular calcium ion that is required to activate sperm motility after spawning. In mammals OR are functionally associated to calcium channels and in fishes calcium is highly required for fish sperm activation. In this study the presence of OR on spermatozoa of two Perciform fish, the sharpsnout seabream ( Diplodus puntazzo, family Sparidae) and the European sea bass ( Dicentrarchus labrax, family Moronidae) was investigated; the two species were chosen for their importance in Mediterranean aquaculture. The analysis by indirect immunofluorescence evidenced the presence of OR on sperm cells of these fishes. Delta, kappa and mu opioid receptors appeared differently localized on the surface of the sperm cells of sharpsnout seabream and European sea bass. Opioidergic receptors on fish spermatozoa could be a new target for reducing stress associated to captivity reproduction in fish farms by EOP antagonists.

Ontogeny and distribution of cholecystokinin-immuno reactive cells in the digestive tract of sharpsnout sea bream, Diplodus puntazzo (Cetti, 1777), during larval development

The appearance and regional distribution of cholecystokinin-immuno reactive cells (CCK-IR) in the developing gut of larval Diplodus puntazzo were studied by means of immunohistochemistry, with the aim of understanding the role of this peptide hormone in the acquisition of digestive capacity. Immunohistochemical reaction showed CCK-IR cells from 10 days after hatching (DAH), near the pyloric sphincter and past the first bend in the midgut, as well as in the hindgut. At 25 DAH CCK-IR cells were scattered throughout the midgut, as well as in the hindgut. Since gastric glands appeared at 30 DAH, CCK-IR cells were most abundant in the anterior midgut, near and including the pyloric caeca, and just afore the ileo-rectal sphincter in the posterior midgut, as well as in the hindgut. In older larvae (39 DAH), CCK-IR cells were mainly distributed in the anterior midgut, including the pyloric caeca, as well as in the hindgut. No CCK-IR cells were detected in the foregut at any stage. The distribution pattern of CCK-IR cells differed from other species which also possess a rotated gut as D. puntazzo. In fact, although cells were abundant in regions where the ingested food is retained, so that they can be stimulated to modulating the release of digestive enzymes, a large number of cells occurred also in the hindgut.

Effect of the interaction between body weight and temperature on growth and maximum daily food intake in sharpsnout sea bream (Diplodus puntazzo)

In experimental culture conditions in tanks, the effect of weight (W: 11–452 g) and temperature (T: 14–29°C) on the growth rate (SGR, % bw day−1) and maximum daily food intake (SFR, % bw day−1) in sharpsnout sea bream (Diplodus puntazzo) was studied. The possible combined effect of both independent variables (W and T) was also analyzed by multiple regression analysis, fitting the data to the equation Ln Y = Ln a + b Ln W + cT + dT2 + eT Ln W. Both SGR and SFR, and therefore feed efficiency (FE = SGR/SFR), were significantly influenced by the interaction between temperature and weight and may be expressed by means of the following equations: Ln SGR = −6.1705 + 0.5809T − 0.0087T2 − 0.0249T Ln W (\( R_{\text{adj}}^{2} \) = 0.949; ANOVA P < 0.0001); Ln SFR = −4.8257 + 0.4425T − 0.0063T2 − 0.0163T Ln W (\( R_{\text{adj}}^{2} \) = 0.964; ANOVA P < 0.0001).The results suggest that the optimum temperature for SGR and FE (TSGRopt and TFEopt), and the temperature at which the maximum SFR (TSFRmax) is reached, decreases with body weight, in accordance with the equations: TSGRopt = 33.297 − 1.435 Ln W; TFEopt = 29.332 − 1.890 Ln W; and TSFRmax = 34.941 − 1.304 Ln W, respectively. In this way, TSGRopt is 28.4, 26.7, and 24.7°C; TSFRmax is 30.5, 28.9, and 27.1°C and TFEopt is 22.9, 20.6, and 18°C for 30, 100 and 400 g body weight, respectively.

Erratum to: Econometric model of viability/profitability of ongrowing sharp snout sea bream (Diplodus puntazzo) in sea cages

Erratum to: Econometric model of viability/profitability of ongrowing sharp snout sea bream (Diplodus puntazzo) in sea cages

Organogenesis of exocrine pancreas in sharpsnout sea bream (Diplodus puntazzo) larvae: characterization of trypsin expression

The ontogeny and differentiation stages of digestive systems related with trypsin expression in larvae of sharpsnout sea bream, Diplodus puntazzo, were investigated from hatching to 40 DAH (days after hatching), and total lengths and weights of larvae were determined. Histologic and enzymatic techniques were used to explain the functional development of the pancreas including trypsin activity. The pancreas was identified as a compact structure located in the region slightly posterior to the liver. At 3 DAH, first anus and then mouth opened. Incipient pancreas secretion polyhedral cells could be first observed as zymogen granules. During larval metamorphosis, the pancreas became diffuse, spreading throughout the mesentery in proximity to the stomach, the anterior intestine and the pyloric caeca. The specific activity of trypsin (42.54±6.8 mU/mg protein(-1)) was found as early as after hatching at larvae size of 2.87±0.34 mm at 0 DAH. Activity further increased until 10 DAH, especially after exogenous feeding. The highest trypsin activity was detected at 25 DAH as 119.26±11.6 mU/mg protein(-1). It is concluded that exocrine pancreas organogenesis is the main critical step in the development of digestive system that results in zymogen granules accumulation and increased trypsin activity.

Econometric model of viability/profitability of ongrowing sharp snout sea bream (Diplodus puntazzo) in sea cages

We have designed and evaluated an ongrowing plant in sea cages as representative of Spanish Mediterranean exploitations with an annual production of 1,000 tonnes, based on the technology already in use for Sparus aurata ongrowing but taking into consideration the zootechnical variables for this species. We used the cost analysis and once defined the accounting structure, and we have used mathematical modelling or econometric to establish indicators of viability/profitability (NPV/IRR) based on the variables chosen for their economic importance in the sensitivity analysis. The highest costs and therefore of greatest economic importance are feed (43.85%) and juveniles (25.04%). The costs analysis points to a profitable business activity, but with a relatively low profitability (benefit/total cost = 7.26%) although benefit/investment is slightly better (15.29%). The break even point suggests that the business will only be viable above a selling price of € 3.69/kg and a production minimum of 709,363 kg/year. The feeding price threshold indicates that the activity is viable up to a cost of € 1.85/kg, which is within the range of sensitivity, while the cost of juvenile threshold (€ 1.17/kg) is much above this range. This underlines the great sensitivity of the activity to feeding costs, although the cost of the juveniles is not so important in this respect. When significant production levels have been reached, it is feasible that the cost of feeding will decrease since the species uses protein of vegetal origin efficiently, especially soy flour. If the minimum selling price is fixed at € 4.21/kg, the cost of feed is 11% lower and the IRR will reach 13.12%, which is an attractive alternative for investors. The econometric model is therefore a very useful tool for evaluating the viability or profitability of new species.

Comparison of proximate and fatty acid composition of the flesh of wild and cultured fish species

The proximate and fatty acid compositions of the flesh of cultured and wild common dentex (Dentex dentex), brown meagre (Sciaena umbra) and sharp-snout sea bream (Diplodus puntazzo) were evaluated. In all batches, cultured fish had higher values of fat contents. The lipids of cultured sharp-snout sea bream contained significantly (p<0.05) higher proportions of 18:1n-9cis, 20:1 n-9, 22:1 n-9, 18:2n-6cis and 22:2cis than the wild form. In addition, cultured common dentex contained significantly (p<0.05) higher proportions of 14:0, 20:1n-9, 18:2n-6cis, 20:5n-3cis and 22:6n-3. For these two species, the total polyenoic fatty acids content and the n-3/n-6 ratio were higher in the cultured than in the wild forms. Cultured brown meagre contained significantly (p<0.05) higher proportions of 14:0, 20:0, 16:1, 18:1n-9cis, 20:1n-9, 22:1 n-9, 24:1 n-9, 18:2n-6cis, 20:5n-3cis and 22:6n-3 than wild brown meagre. The total monoenoic and polyenoic fatty acid contents were higher in the cultured brown meagre, whereas the corresponding total saturated fatty acid content and the n-3/n-6 ratio were lower.

Sunflower meal as a partial substitute in juvenile sharpsnout sea bream ( Diplodus puntazzo) diets: Amino acid retention, gut and liver histology

The suitability of sunflower meal (SFM) as a substitute for fish meal was evaluated in sharpsnout sea bream fingerlings (14 g) by feeding diets in which 0, 10, 20 or 30% of crude protein provided by fish meal was substituted with SFM. The experiment lasted 125 days and survival at the end of the experiment was 95%. The effect of SFM level on growth parameters were not significant ( P < 0.05). Fish were hand-fed to apparent satiation and feed intake ratio was not affected by SFM inclusion in the diet. Final live weight was 100 g for all fish fed all diets. Nutritional and biometric parameters were not affected by SFM substitution, but in body composition fish fed the diet with 20% of crude protein replaced by SFM substitution showed the lowest crude lipid level and the highest moisture content. Crude protein efficiency, gross energy efficiency and amino acid composition and retention of fish fed the various diets did not reach statistical differences. No histological alteration were found in liver, but an increment in goblet cells was observed in mucosa folds, perhaps as a consequence of SFM substitution or due to the high content of arginine and aspartate, known to be responsible for some immune responses. The results of this experiment demonstrated that SFM can supply up to 30% of crude protein in diets for feeding sharpsnout sea bream juveniles without any adverse effect on fish growth, liver and gut histology and amino acid composition and retention.

Ultrastructural aspects of previtellogenic oocyte growth in hermaphrodite sharpsnout seabream,Diplodus puntazzo(Teleostei, Sparidae)

This paper describes various aspects of previtellogenic oocyte growth in sharpsnout seabream, Diplodus puntazzo , is an important marine culture fish species in the Mediterranean. The ultrastructural characteristics of nuclear morphology, nuclear-cytoplasmic ratio and the starting of the follicle envelope formation were described in detail. These cells do not significantly differ from those of the other teleost species. The ultrastructural aspects provide new information on the reproductive biology of Sparidae.

The Effect of Seasonality on the Health and Growth of a Newly Recorded Myxobolus Species Infecting Cultured Sharp Snout Seabream (Diplodus puntazzo C.)

The prevalence, intensity, and pathology of a Myxobolus sp. affecting the kidneys of cultured Diplodus puntazzo C. during the period 2003-2005 are described. The study included data collected from the largest farm in southern Greece where a high rate of mortality due to myxosporean infection occurred. Sharp snout seabream reared in sea cages in southern Greece underwent microbiological, parasitological, and histological examinations, while measurement and identification of parasites was performed immediately after sampling. Samplings were made daily from winter 2003 to autumn 2005. Prevalence was estimated for each season (autumn, winter, spring, and summer) each year (2003, 2004, and 2005). The Myxobolus sp. was detected in high numbers and with a high prevalence of infection in the renal interstitial tissue, especially during the summer months. The growth rate of infected D. puntazzo was very slow during the study period in comparison to cultured Sparus aurata L. and uninfected D. puntazzo.

Severe mortality in mesocosm-reared sharpsnout sea bream Diplodus puntazzo larvae due to epitheliocystis infection

This paper describes severe mortalities recorded in sharpsnout sea bream Diplodus puntazzo larvae reared in mesocosms. The mortalities were attributed to epitheliocystis infection. The pathology associated with the disease is described using histological techniques. Microscopical examination showed a massive infection of the skin, fins, and oral cavity, with impaired feeding, respiration, and osmoregulation being the most likely cause of death. This is the first report of epitheliocystis disease in sharpsnout sea bream and in fish at such an early developmental stage.

Ontogeny of the digestive tract in sharpsnout sea bream Diplodus puntazzo (Cetti, 1777).

The ontogeny of the digestive tract was studied histologically and histochemically in sharpsnout sea bream Diplodus puntazzo from hatching (0 DAH, Days After Hatching) until day 57 (57 DAH). At hatching, the digestive tract appeared as a histologically undifferentiated straight tube lying dorsally to the yolk sac. When the mouth opened at 3 DAH, the digestive tract was differentiated into buccopharynx, oesophagus, incipient stomach and intestine. The pancreas, liver and gall bladder were also differentiated at this stage and both the bile and pancreatic duct had opened into the anterior intestine. Active feeding began in 50% of larvae at 4 DAH, although permanence of yolk reserves until 7 DAH suggests a period of both endogenous and exogenous feeding. Nutrient absorption was first visible from 5 DAH, as colourless supra- and infranuclear vacuoles in the anterior intestinal mucosa, suggesting a lipid content, as well as supranuclear, eosinophilic vacuoles, containing protein, in the posterior intestinal mucosa. Early caecal development could be detected from 10 DAH, whereas gastric glands appeared at 30 DAH, indicating the transition from larval to juvenile stage and the acquisition of an adult mode of digestion. Goblet cells appeared in the digestive tract of sharpsnout sea bream larvae shortly after first feeding. The mucus content of goblet cells varied with the digestive region and, in the buccal cavity and oesophagus, also with the developmental phase. This study provides knowledge for better husbandry practices in the aquaculture industry, as well as for the implementation of future nutritional studies.