Florida Pompano Trachinotus Carolinus Research Articles

Surf-zone fish assemblage structure and its diel variability in an ocean beach of Espírito Santo (Central Brazilian coast)

We characterized the surf-zone fish assemblage structure of an ocean beach on the central coast of Brazil (Guriri Beach, Espírito Santo) and assessed its diel variability. Like the entire Espírito Santo coast, Guriri Beach was also affected by ore tailings from the Fundão dam, which collapsed on November 5, 2015. Monthly samplings were carried out before the dam collapse along a year cycle (May 2013-April 2014), during the day and night in the neap tide, using a beach seine. A total of 2217 specimens were caught (1017 during the day and 1200 at night), distributed in 36 fish species and 20 families. Juveniles of the kingcroaker Menticirrhus spp., great pompano Trachinotus goodei, Florida pompano Trachinotus carolinus, littlescale threadfin Polydactylus oligodon, and Atlantic sabretooth anchovy Lycengraulis grossidens dominated the fish fauna, accounting for 84% of the total capture. The fish assemblage structure changed irregularly between day and night throughout the year. P. oligodon and Menticirrhus spp. were more abundant at night, whereas T. carolinus and L. grossidens were more abundant during the day. In most cases, no significant change was detected in fish abundance and richness between the day and night; when significant differences were detected, abundance and richness were higher at night. Our findings could support a monitoring program of the local surf-zone fish fauna and serve as before-impact data, allowing more accurate quantification of the ore tailings' impacts on the local fish biodiversity.

Growth, body composition, and distal intestine histology of Florida pompano Trachinotus carolinus in response to dietary inclusion of hydrolyzed salmon meal and pH adjustment

ABSTRACT In this study, we aimed to investigate the inclusion effect of hydrolyzed salmon meal (HSM) in combination with enzyme-treated soybean meal (ESBM) with or without pH adjustment to completely replace dietary FM on the growth, body composition, and the distal intestine condition of the fish. For that purpose, four experimental diets were formulated to be iso-nitrogenous and iso-lipidic and to contain 400 g kg−1 crude protein and 80 g kg−1 lipid. A reference diet contained 150 g kg−1 FM, 450 g kg−1 soybean meal (SBM), and 39.5 g kg−1 ESBM, and the second diet was formulated replacing FM with 190.6 g kg−1 ESBM. The third diet was produced by supplementing 40 g kg−1 hydrolyzed salmon meal (4% HSM) into the diet formulation at the expense of ESBM, and the fourth diet was produced similar with the third diet, but the pH of the diet was adjusted to match the value in the reference diet (4% HSMA). All test diets were supplemented with taurine at the level of 5 g kg−1. Diets were fed to apparent satiation to triplicate groups of Florida pompano juveniles (mean weight 11.88 ± 0.18 g). After 8 weeks of growth, there were no significant differences in the final weight, percentage weight gain, thermal growth coefficient, feed intake, survival rate, and feed conversion ratio in fish offered the various diets. Nor were significant differences observed in the dry matter composition of the fish in all treatments and only minor changes in the histomorphological of distal intestine as the FM was replaced by plant ingredients. Overall, the adjustment of pH level of the diet containing 4% HSMA did not have any significant effect on the growth and physiological function of fish compared to the group of fish fed with diet without pH adjustment.

Trophic Levels Predict the Nutritional Essentiality of Polyunsaturated Fatty Acids in Fish—Introduction to a Special Section and a Brief Synthesis

AbstractDefining nutritional fatty acid essentiality in fish nutrition is complex given the wide range of taxonomic (e.g., divergence among species subjected to different selective pressures), biological (e.g., trophic levels and environmental tolerances), and external (e.g., experimental conditions and differences in feed formulation and manufacturing) factors involved, all of which can influence absolute requirements. Fishes vary in their ability to meet the physiological demand for long‐chain (LC) polyunsaturated fatty acids (PUFAs; i.e., 20:4[n‐6], 20:5[n‐3], and 22:6[n‐3]) via elongation and desaturation of C18 PUFA (i.e., 18:2[n‐6] and 18:3[n‐3]) precursors. Previous attempts to generalize dietary fatty acid requirements have been focused on thermal and salinity preferences, suggesting—in many cases inaccurately—that coldwater and/or marine fish exhibit dietary requirements for LC‐PUFAs but warmwater and/or freshwater species do not. Here, we provide a review of the current literature on the subject of dietary fatty acid essentiality in fish and introduce the experiments that form the basis of this special section. In these experiments, we tested the nutritional essentiality of C18 PUFAs versus LC‐PUFAs in feeds for five finfish relevant to intensive aquaculture: Rainbow Trout Oncorhynchus mykiss, Channel Catfish Ictalurus punctatus, Nile Tilapia Oreochromis niloticus, Florida Pompano Trachinotus carolinus, and hybrid Striped Bass (White Bass Morone chrysops × Striped Bass M. saxatilis), hypothesizing that the nutritional essentiality of C18 PUFAs versus LC‐PUFAs would be determined by trophic level. The findings collectively suggest that trophic level is the most reliable predictor of C18 PUFA versus LC‐PUFA nutritional essentiality in fish.

Assessing Polyunsaturated Fatty Acid Essentiality in Florida Pompano

AbstractWe evaluated the growth performance and fatty acid composition of juvenile Florida Pompano Trachinotus carolinus that were fed diets containing different combinations of n‐3 and n‐6 polyunsaturated fatty acids (PUFAs) to assess the relative importance of C18 PUFAs and long‐chain (LC) PUFAs in meeting the essential fatty acid requirements of this species. Juvenile fish (mean ± SD =47.4 ± 0.6 g/fish) were fed diets containing different combinations of n‐3 and n‐6 PUFAs: a positive control containing menhaden fish oil, a negative control containing hydrogenated soybean oil, and experimental diets containing hydrogenated soybean oil amended with ethyl esters of 18:3(n‐3); 18:3(n‐3) and 18:2(n‐6); 22:6(n‐3); 22:6(n‐3) and 20:4(n‐6); or 20:5(n‐3), 22:6(n‐3), and 20:4(n‐6). After 7 weeks, weight gain, feed conversion ratio, and specific growth rate were significantly greater among fish that were fed the positive control feed in comparison with those that received the negative control feed. The addition of n‐3 and/or n‐6 PUFAs to the negative control formulation did not significantly improve performance in any case, although numeric improvements observed for weight gain and feed conversion ratio appeared to suggest some advantage from providing a complement of both n‐3 and n‐6 LC‐PUFAs in the diet. Fatty acid composition varied significantly between all tissues, generally reflecting dietary fatty acid profiles. Tissue fatty acid profiles suggest that Florida Pompano have some ability to elongate and desaturate fatty acids and may be able to survive on diets containing C18 PUFAs, but they perform optimally when provided with LC‐PUFAs directly.

Partial or total replacement of fish meal in the diets of Florida pompano Trachinotus carolinus

Two trials were conducted to evaluate the efficacy of commercial enzyme-treated soy (ESBM) to replace the use of fish meal (FM) in practical diets for Florida pompano Trachinotus carolinus. The reference diet which has been run in numerous trials for Florida pompano was formulated using 150, 466 and 80 g/kg of FM, soybean meal and corn protein concentrate respectively. In trial 1, test diets were produced by replacing FM with 30.8, 61.4 and 92.1 g/kg of ESBM. In trial 2, test diets were produced by replacing FM with 28.9, 89.8, 120.1 g/kg of ESBM. Triplicate group of fish in trial 1 (mean weight = 13.05 ± 0.34 g) and trial 2 (mean weight = 18.45 ± 0.49 g) was fed these diets to apparent satiety for 8 weeks. Growth performance was affected as the dietary FM was replaced with ESBM. In trial 1, final weight (FW), percentage weight gain and thermal growth coefficient were lower in 6 g/kg of FM compared to 15 g/kg, while feed conversion ratio significantly higher in fish fed the lowest inclusion level of FM (6 g/kg). In trial 2, FW was significantly lower when FM completely replaced by ESBM and no significant differences in other growth parameters. In all trials, no significant differences were observed in terms of crude protein, moisture, fat, crude fibre, dry matter and ash content of the fish. No significant differences in serum levels of total protein, albumin, alkaline phosphatase, alanine transaminase, aspartate transaminase, glucose and bile acids were observed in either trial. However, in trial 1, serum cholesterol level was higher in fish fed 150 g/kg FM compared to other dietary treatments. The histomorphological structure of liver and distal intestine was slightly affected by lower inclusion level of FM. Overall, there was a decreasing trend in pompano growth performance as the inclusion of FM decreased. All parameters indicated that ESBM could be used to reduce the inclusion of FM from 150 to 90 g/kg.

Phylogenomic characterization of red seabream iridovirus from Florida pompano Trachinotus carolinus maricultured in the Caribbean Sea.

Between 2010 and 2016, six mortality events were observed in Florida pompano (Trachinotus carolinus) maricultured in the Dominican Republic. Histopathological examination andconventional PCR confirmed a megalocytivirus (MCV) infection in each case. Subsequently,next-generation sequencingand phylogenomic analyses confirmedthat MCV DNA was present in theinfected pompano tissue samples from 2010, 2014, and 2016, and each was determined to be red seabream iridovirus (RSIV). Annotation of the RSIV genome sequences identified 121 open reading frames, and BLASTN analysis revealed the highest nucleotide sequence identity(> 99%) to a RSIV clade 1 MCV isolated from a moribund red seabream (Pagrus major) maricultured in Japan. These cases represent the first fully sequenced RSIV genomes detected outside of Asia and are the earliest reports of MCV infections in Florida pompano. This recent geographical expansion of RSIV warrants further attention to determine its potential economic and ecological impact.

Quantitative taurine requirement for juvenile Florida pompano (Trachinotus carolinus ) fed soy-based practical diets

Florida pompano Trachinotus carolinus is an important species in which the essentiality of taurine has been demonstrated, yet a quantitative requirement has not been estimated. Two experiments were conducted where a combined twelve diets were formulated with graded levels of taurine (ranging 1.6–41.6 g/kg dry matter) and fed to juvenile pompano (initial weight 7.73 and 4.37 g in trial 1 and 2, respectively). Dose responses were observed in terms of growth, feed efficiency and whole-body taurine content, but there was no effect on survival. Several regression models were evaluated to determine the most appropriate one to draw conclusions from. A 4-parameter saturation kinetic model was selected to model feed efficiency, while a 5-parameter saturation kinetic model fitted the growth data (as thermal-unit growth coefficient, TGC). A broken-quadratic model served to estimate a breaking point in the whole-body taurine content, although it also showed that whole-body taurine kept increasing even at dietary levels in far excess of the requirement. The dietary taurine requirement was estimated at 2.5 g/kg (2.0–3.3 g/kg, 95% CI, dry matter basis) based on feed efficiency, while TGC was maximized at levels between 4.9 and 31.4 g/kg dietary taurine.

Red seabream iridovirus associated with cultured Florida pompano Trachinotus carolinus mortality in Central America.

Mariculture of Florida pompano Trachinotus carolinus in Central America has increased over the last few decades and it is now a highly valued food fish. High feed costs and infectious diseases are significant impediments to the expansion of mariculture. Members of the genus Megalocytivirus (MCV), subfamily Alphairidovirinae, within the family Iridoviridae, are emerging pathogens that negatively impact Asian mariculture. A significant mortality event in Florida pompano fingerlings cultured in Central America occurred in October 2014. Affected fish presented with abdominal distension, darkening of the skin, and periocular hemorrhages. Microscopic lesions included cytomegalic 'inclusion body-bearing cells' characterized by basophilic granular cytoplasmic inclusions in multiple organs. Transmission electron microscopy revealed arrays of hexagonal virions (155-180 nm in diameter) with electron-dense cores within the cytoplasm of cytomegalic cells. Pathological findings were suggestive of an MCV infection, and the diagnosis was later confirmed by partial PCR amplification and sequencing of the viral gene encoding the myristylated membrane protein. The viral sequence revealed that the fingerlings were infected with an MCV genotype, red seabream iridovirus (RSIV), previously reported only from epizootics in Asian mariculture. This case underscores the threat RSIV poses to global mariculture, including the production of Florida pompano in Central America.

Effects of various levels of squid hydrolysate and squid meal supplementation with enzyme-treated soy on growth performance, body composition, serum biochemistry and histology of Florida pompano Trachinotus carolinus

The purpose of this study was to evaluate the impact of plant-based diets supplemented with various levels of enzyme-treated soybean meal (ESBM) and squid products on the growth, proximate composition, serum biochemistry, and liver and intestinal histological alterations in pompano (Trachinotus carolinus). A 15% poultry by-product meal (PBM) based practical diet was used as a reference and basal diet was produced by replacing PBM with ESBM. Basal diet was then modified to contain varying levels of squid products. Squid hydrolysate (SH) and squid meal (SM) were added to basal diets, to produce diets containing 1, 2 and 4% of the squid products. A total of eight experimental diets were each fed to quadruplicate groups of 20 pompanos (mean initial wt=7.68±0.1g) in a recirculating rearing system for 56d. Results from the growth trial indicate that fish fed with basal diet exhibited significantly lower growth performance and feed utilization as compared to fish fed with PBM. The addition of 4% SH improved the response of basal diet and did not show any significant difference in terms of growth performance as compared to PBM. Whole body proximate and amino acids composition of fish were not significantly different among fish reared on any of the diets. Data on mineral composition of fish showed that the content of phosphorus and calcium were significantly higher in fish fed with basal diet compared to other treatments. Total protein and cholesterol level of fish fed PBM were significantly lower compared to basal diet. Total albumin, alanine transaminase, aspartate transaminase, and bile acids were similar among the dietary treatments. Fish fed with basal diet showed disordered vacuolization in the liver and decreased the lamina propria thickness in the intestine. The inclusion of 4% SH partly prevented the alteration of liver and distal intestine of Florida pompano and findings were similar to fish fed with PBM. Based on these results, combination of ESBM and 4% SH has the potential to serve as an alternative protein source and attractant to improve the efficacy of plant-based diet for pompano.

Development of plant-based diets and the evaluation of dietary attractants for juvenile Florida pompano, Trachinotus carolinus L.

Sustainable and profitable commercial aquaculture production of marine fish species is dependent on the development of sustainable protein sources as substitutes for expensive animal meals such as fishmeal (FM). Previous Florida pompano Trachinotus carolinus studies have indicated that poultry by-product meal (PBM) and meat and bone meal can be used to produce a FM-free diet if suitable levels of nutrients (such as taurine) are included in the diets. In this study, we attempted to develop an all-plant protein diet by removing the animal proteins in practical diets for pompano by substituting back select ingredients. A series of eight FM-free diets were formulated, four systematically replaced soybean meal (SBM) with soy protein concentrate (SPC) and four replaced PBM with SPC. Based on the results, there is no clear disadvantage to the use of SPC as a replacement for SBM. However, the complete removal of PBM resulted in reduced performance. Two additional growth trials were conducted to supplement additional amino acids including glycine, valine and histidine, a proprietary chemical attractant mix, fish protein concentrate and squid hydrolysate to improve the growth of pompano when fed all-plant protein diets. The only improvement in performance occurred with the squid hydrolysate. These results demonstrate that using soybean meal, soy protein concentrate and corn gluten meal as the primary protein sources, a plant-based feed formulation can be developed, but the removal of all animal proteins is not yet feasible.

Differential Predictors of Adult versus Juvenile Distributions of Two Coastal Pelagic, Surf Zone Fishes along the Northern Gulf of Mexico

AbstractAs coastal human populations increase and offshore fishery regulations become more stringent in the northern Gulf of Mexico, nearshore fisheries may be subjected to increased exploitation. Spanish Mackerel Scomberomorus maculatus and Florida Pompano Trachinotus carolinus are two nearshore, coastal migratory pelagic species vulnerable to undergoing changes in fishing pressure; however, information is incomplete in regards to understanding their current distributions and movement patterns, both of which are important for effective fishery management. We used a 2‐year (2011–2012) gill‐net and seine survey to assess surf zone distributions of Spanish Mackerel and Florida Pompano in the northern Gulf of Mexico (Horn Island, Mississippi, to Pensacola, Florida). Unbiased catch‐per‐unit‐effort estimates (by the delta method) were greatest in Alabama and during spring months. Lowest catches occurred during the warm summer months. Overall, subadult–adult Spanish Mackerel presence could be predicted (using a delta‐lognormal general linear model) by geographic area, beach habitat, and depth. Florida Pompano presence could be predicted by month and beach habitat. For both species, the abundance could not be predicted by any of the examined variables. Juvenile Florida Pompano presence, contrastingly, could be predicted by month and salinity, and abundance by month and water temperature. Both species had spatiotemporal variability in distribution and catch rates, but beach habitat appeared to be a better predictor for subadults and adults of both species, whereas month and salinity were better predictors for juvenile Florida Pompano catches. Greater catches generally corresponded with proposed migration patterns but also suggest that individuals, at least temporarily, leave the surf zone during the day in the warm summer months. Furthermore, although legal‐sized individuals of both species can co‐occur in the surf zone in the northern Gulf of Mexico, the increase in Spanish Mackerel presence with depth suggests that Spanish Mackerel fisheries could potentially move further offshore to avoid user conflict with Florida Pompano fisheries.Received March 16, 2016; accepted August 1, 2016 Published online October 14, 2016

Digestibility of feed ingredients in Florida pompano,Trachinotus carolinusadapted to either sea water or low salinity

Seven potential feed ingredients were evaluated for digestibility with Florida pompano Trachinotus carolinus using extruded diets. Ingredients included Special Select™ menhaden meal, fishery processing by-product (Montlake meal), NuPro® yeast extract, canola protein concentrate, corn protein concentrate, barley protein concentrate and Spirulina. Digestibility values were determined when fish were held at 3 and 28 g L−1 salinity to determine the effect of salinity on digestibility. With the exception of the canola protein concentrate, the coefficients were numerically higher in pompano held at 28 g L−1. No significant differences were detected for apparent crude protein or apparent energy digestibility between the two salinities. Amino acids were highly available from the two marine-based ingredients and the barley and canola concentrates. The availability of alanine, leucine, isoleucine and phenylalanine was significantly higher (P < 0.05) from the barley protein concentrate at 28 g L−1 than 3 g L−1 salinity. Methionine and phenylalanine were highly available from all the ingredients except the yeast protein. Conversely, glycine was not well utilised from any of the ingredients. The apparent digestibility coefficients provided here allow for more precise formulation of diets for Florida pompano reared in both seawater and low-salinity environments.

Fish oil replacement in feeds for juvenile Florida Pompano: Composition of alternative lipid influences degree of tissue fatty acid profile distortion

Replacing long-chain polyunsaturated fatty acid (LC-PUFA)-rich fish oil with alternative lipids in Florida Pompano Trachinotus carolinus feeds is likely to cause tissue LC-PUFA depletion in a manner similar to that observed in other species; however, there is little information available regarding fish oil sparing in this species. Moreover, it is unknown whether alternative lipids with different levels of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), or C18 polyunsaturated fatty acids (C18 PUFAs) are equally suitable in this context. Accordingly, we assessed the production performance and tissue composition of juvenile Florida Pompano (43.4±0.2g) fed diets containing menhaden fish oil (FISH) or 25:75 blends of fish oil and standard soybean oil (C18 PUFA SOY), MUFA-enriched soybean oil (MUFA SOY), SFA-enriched soybean oil (SFA SOY), palm oil (PALM), or poultry fat (POULTRY). After 8weeks, all diets were well accepted, and weight gain (228±20%, grand mean±SE) and specific growth rate (2.2±0.1% body weight/day) were unaffected by dietary treatment. Feed conversion ratio, feed intake, and hepatosomatic index varied among treatments; however, the ranges of values observed were relatively narrow (FCR=1.33–1.61, feed intake=3.09–3.65% body weight/day, HSI=1.1–1.5) and pairwise comparisons revealed few differences among treatments. Fatty acid profiles of the fillet, liver, and eye tissues generally mirrored dietary fatty acid composition, whereas the brain tissue was more resistant to dietary influence. Compared to those fed the FISH diet, fillets of fish fed the reduced fish oil diets had lower levels of n-3 fatty acids and LC-PUFAs, and greater levels of the fatty acids that were abundant in the alternative lipids. These trends were observed, albeit to a lesser extent in liver and eye tissues, but not in brain tissue, which was relatively resistant to diet-induced compositional change. In general, tissue fatty acid profile distortion was greatest among fish fed the MUFA SOY and C18 PUFA SOY diets, least overt among fish fed the SFA SOY diet, and intermediate among fish fed the PALM and POULTRY diets. All alternative lipids appeared effective as partial substitutes for menhaden fish oil, but fully hydrogenated, SFA-rich soybean oil may offer some strategic advantage in terms of limiting diet-induced modification of tissue fatty acid profile in Florida Pompano. Statement of relevanceAs there are few studies addressing lipid nutrition of Trachinotus spp. and there is scarce information regarding the influence of different alternative lipid source on tissue levels of LC-PUFAs in these species, this study is relevant to aquafeed manufacturers and those culturing Florida Pompano and other Trachinotus spp. The present results provide valuable information regarding alternative lipids in marine carnivorous finfish feeds and their effects on fish performance and tissue fatty acid composition. Further, these findings highlight the promising potential of fully hydrogenated, SFA-rich soybean oil in aquafeeds.

Evaluation of various cottonseed products on the growth and digestibility performance in Florida pompano Trachinotus carolinus

Two 10-week growth trials and digestibility trials were conducted to assess the efficacy of various cottonseed products in practical diets for the Florida pompano Trachinotus carolinus. In trial 1, a basal diet containing 150g/kg of fishmeal (FM150) was modified by the iso-nitrogenous replacement of fishmeal (FM) with cold pressed cottonseed flour (CSF) resulting in diets containing 100g/kg (FM100), 50g/kg (FM50) and 0g/kg (FM0) of fishmeal. To determine if lysine was limiting in the FM0 diet, two additional diets were developed using a high lysine corn protein concentrate (FM0-LCPC) or a crystalline source of lysine (FM0-CL). In trial 2, the basal diet was formulated to contain 457.0g/kg of soybean meal (SBM) and 150g/kg of poultry by-product meal (PBM), the other three diets were made by replacing SBM on an iso-nitrogenous and iso-lipidic basis with varying cottonseed flours (CSF) which included cottonseed flour (CSF), gossypol-extracted cottonseed flour (ECSF), and glandless cottonseed flour (GCSF). In trial 1, results showed that the use of up to 196g/kg of CSF with a lysine supplement does not inhibit growth performance of the fish. In trial 2, no significant differences were observed in growth performance of the fish maintained on the various diets. Although gossypol was detected in the livers of fish offered diets with gossypol, no differences were observed in the cells of the liver samples or organization of the liver cells amongst any of the treatments. After each growth trial, apparent digestibility coefficients for dry matter (ADMD), energy (AED), and protein (APD) were determined for primary ingredients. In the first digestibility trial, no significant differences were observed with regard to digestibility coefficients for FM, CSF, and corn protein concentrate (CPC). In the second digestibility trial, no significant differences were observed on ADMD and AED for the ingredients GCSF, CSF, and ECSF. However, the APD values for ECSF were found to be significantly lower than those values of GCSF and CSF. Results of this study provide support that cottonseed products are acceptable for use in practical diets for Florida pompano. Statement of relevanceIn this study, we assessed the efficacy of various cottonseed products in practical diets for the Florida pompano. These findings will be useful because the feed producers need the growth and digestibility data of the cottonseed products as an alternative ingredient to use in the diet formulation. The conclusions in this manuscript provide valuable information which researchers and feed producers need to use the cottonseed products in diets of this species.

Investigation of biomarkers of early taurine deficiency in Florida pompano Trachinotus carolinus

Despite garnering high interest in fish nutrition as an essential amino acid in a number of teleosts, the metabolic and physiological functions of taurine remain poorly described in fish. This study describes the postprandial changes of taurine in Florida pompano juveniles fed a taurine-replete diet, followed by a wide screening of metabolic and physiological markers when fed a taurine-deficient diet over 16days. The goal was to screen for markers of early taurine deficiency and identify its initial components. Postprandial taurine levels varied between 106.75 and 170.37μg/ml with a mild peak at 2–4h after feeding, and decreased to 72.1% of the baseline value at 6h. Fish fed the taurine-deficient diet did not have reduced hematocrit or increased bilirubin, suggesting an absence of hemolysis. However, linear decreases in alkaline phosphatase activity and in bile acid content were observed (R2=0.5968 and 0.5613, respectively, P<0.005). Filet composition showed an overall linear increase in moisture (R2=0.2666, P=0.0338) and a marked, linear loss in lipid over time (R2=0.4059, P=0.0059). There was also a drastic, quadratic decrease in all amino acid content of the liver (R2>0.75, P<0.0001), which had decreased by 40% by day 16. Notably, levels of taurine, hydroxylysine and hydroxyproline sharply decreased and remained low. In the filet however, levels of most amino acids were not affected, except for hydroxyproline, hydroxylysine, proline, and glycine, whose levels increased significantly by day 16 while taurine levels had decreased. Serum levels were variable, and no pattern of change could be identified. Liver histology revealed marked vacuolation of hepatocytes and significant glycogen accumulation. Finally, hepatic mitochondrial proteins quadratically decreased with time (R2=0.6218, P=0.0007), paralleled with a severe linear decrease in cytochrome c oxidase (COX) specific activity (R2=0.5940, P=0.0002). This indicates that the mitochondrial electron transport chain was greatly disrupted, and which resulted in poor hepatic metabolism and production of oxidative radicals. In summary, the present study describes the first screening for metabolic and physiological biomarkers of early taurine deficiency. Although we found no evidence of overt hepatocellular damage during the course of the experiment, we observed significant alterations of cellular metabolism, especially in hepatocytes (i.e., histology, amino acid content, COX activity). Changes in serum parameters were detected, although their suitability as biomarkers will require additional research. The absence of hematocrit decrease is noteworthy in light of published literature; longer term investigations are necessary to further our understanding of taurine functions in teleosts. Statement of relevanceThis manuscript presents results of scientific research relevant to the field of aquaculture. Taurine is a nutrient of great importance for many teleost species and for the sustainability of fish feeds; yet its metabolic functions remain unclear. This study constitutes, to the authors' knowledge, the first attempt at characterizing these functions. These results shed light on the complexities of taurine metabolism and emphasize possible hypotheses for future research. Therefore this study presents novel research results of high interest to the aquaculture and fish biology communities.

Complete mitochondrial genome of Florida pompano Trachinotus carolinus (Teleostei, Carangidae)

The complete mitochondrial genome sequence of Florida pompano Trachinotus carolinus was determined by the overlapped polymerase chain reaction. The complete mitochondrial DNA sequence is 16,544 bp in length. It consists of 13 protein-coding genes, 22 transfer RNA genes, two rRNA genes and two non-coding regions. Overall base composition of its mitochondrial genome is estimated to be 28.68% for A, 16.27% for G, 26.00% for T, 29.06% for C, respectively, with a high A+T content (54.68%). The control region contains three conserved sequence blocks, a termination-associated sequence and a TATA box. The sequence data of T. carolinus can provide useful information for the studies on population structure, molecular systematic, stock evaluation and conservation genetics. It is also helpful to develop the rational management strategies for T. carolinus resource.

Development of a semipurified test diet for determining amino acid requirements of Florida pompano Trachinotus carolinus reared under low-salinity conditions

Abstract Two trials were conducted to develop a semipurified test diet for determining indispensable amino acid (IAA) requirements for Florida pompano Trachinotus carolinus . The objective of the first trial was to evaluate casein and corn gluten meal as principal intact protein sources, and the ability of Florida pompano to utilize l -crystalline amino acids in the diet. Eight isonitrogenous (42% crude protein) and isoenergetic (22.0 kJ/kg) diets were formulated. A 2 × 4 factorial was employed to evaluate the two intact proteins, each with four amino acid profiles that mimicked the ratio of IAA in pompano whole body, pompano unfertilized eggs, menhaden fish meal, or unsupplemented negative control. Growth and efficiency were significantly better ( P The objective of the second trial was to re-evaluate the same IAA profiles in 46% crude protein and 22.0 kJ/kg casein-based diets to evaluate their performance relative to each other and to a practical type fish meal-based control diet. Growth and feed conversion were significantly better ( P P

Do surf zones in New Jersey provide “nursery” habitat for southern fishes?

The fishes of the energetic surf zone of exposed ocean beaches are poorly known, especially along the U.S. east coast. We investigated the role that surf zones in southern New Jersey have as habitat by describing the young-of-the-year fishes caught by seines within the surf zone from May through October in 1998, 1999, 2005 and 2006. In addition, we investigated the nursery role of these surf zones by examining abundance, growth, and inferred survival during the summer for the dominant locally (New Jersey) and southern (south of Cape Hatteras) spawned species. At least three southern species, i.e. bluefish Pomatomus saltatrix (Cohort I), white mullet Mugil curema, and Florida pompano Trachinotus carolinus successfully use New Jersey surf zones as nurseries during the summer. It is clear that bluefish (Cohort I) contributes to the adult population and it is likely for the other southern species. Ultimately, the nursery contribution of surf zones and other habitats at the northern limits of the range of southern species depends on whether surviving juveniles can successfully emigrate to overwinter habitats and complete their life history.

Soy Protein Concentrate as an Alternative Ingredient in Florida Pompano (Trachinotus carolinus) Diets

Current research is intended to develop cost-effective, plant-based diets for intensive production of Florida pompano (Trachinotus carolinus). Three growth trials were conducted with juvenile pompano over a 106- to 115-day period. The trials evaluated the systematic substitution on an equal protein basis of (1) menhaden fish meal, FM with soy protein concentrate (SPC), and (2) solvent extracted soybean meal (SBM) with SPC. This confirmed the reduction of FM and evaluated the possible nutrient restrictions of methionine (M) and phosphorus (P) in low FM, high SPC diets. There was no significant reduction in growth parameters when FM was reduced from 300 to 150 g/kg. There was a significant improvement in fish performance with increased SPC concentrations substituted for SBM in diets containing 150 g/kg of FM. All growth parameters indicated a favorable response for inclusion of SPC up to 240 g/kg. The addition of P and M did not significantly improve growth.

Replacement of fishmeal with poultry by-product meal in the diet of Florida pompano Trachinotus carolinus L.

The development of cost-effective and growth-promoting diets for Florida pompano (Trachinotus carolinus L.) is necessary for a feasible pompano aquaculture industry in the United States. However, research efforts to reduce the utilization of marine ingredients in aquatic feeds are needed to accomplish such a goal. Three independent growth trials were conducted to evaluate the replacement of fishmeal in the diet of Florida pompano. The basal diets were formulated to contain 40% crude protein and 10% lipid using solvent extracted soybean meal and corn gluten as the primary and fixed protein sources. In Trial I (10weeks) the basal diet containing 15% fishmeal (FM15) was modified by the isonitrogenous replacement of fishmeal with poultry by-product meal resulting in diets containing 10% (FM10), 5% (FM5) and 0% (FM0) fishmeal. In Trial II (12weeks), the FM0 diet was supplemented with methionine (M), lysine (L), and taurine (T), serving as the basal diet (MLT) for the evaluation of potential limitations in these amino acids. By deleting individual amino acids, test diets without methionine (LT), lysine (MT) or taurine (ML) supplements were formulated. In Trial III (8weeks), the FM0 diet from Trial I served as the basal diet (0% Tau) for the evaluation of potential limitations in taurine. Fish in replicate tanks (n=3) were fed one of the randomly assigned test diets two times daily. The total replacement of fishmeal in Trial I resulted in depression of fish performance while the performance of fish offered test diets with 5–15% fishmeal did not differ significantly. Reductions in weight gain (from 338.1 to 260.4%), feed efficiency (from 0.53 to 0.40), protein and energy retention (from 19.6 to 12.4% and from 20.4 to14.2%, respectively) were observed in fish fed the FM15 and FM0 diets, respectively (P<0.05). In Trial II, growth performance of pompano did not change (P>0.05) by the removal of supplemental methionine, lysine or taurine from the FM0 diet albeit, numerically the removal of taurine produced the smallest fish. In Trial III, the supplementation of taurine to the FM0 diet at 0.75g/100 (0.75% Tau) improved the weight gain (from 587.7 to 773.3%), feed efficiency (from 0.50 to 0.64), and protein retention (from 20.5 to 24.3%) of pompano (P<0.05). Based on these results, we concluded that poultry by-product meal is a good alternative ingredient for fishmeal in the diet of Florida pompano and that this species appears to have a minimum dietary requirement for taurine.