Cobia Research Articles

Preparation and characterisation of Punica granatum pericarp aqueous extract loaded chitosan-collagen-starch membrane: role in wound healing process.

Engineered scaffolds made from natural biomaterials are crucial elements in tissue engineering strategies. In this study, biological scaffold like chitosan-collagen-starch membrane (CCSM) loaded with the antibacterial agent, Punica granatum pericarp aqueous extract was explored for enhanced regeneration of epithelial tissue during wound healing. Collagen was extracted from Rachycentron canadum fish skin. Membranous scaffold was prepared by mixing collagen, starch and chitosan in a fixed proportion, loaded with aqueous extract of P. granatum and its anti-pseudomonal activity was studied. Morphological characterization by SEM and mechanical property like tensile strength of the membrane were studied. Excision wound of 2 cm(2) size was induced in Guinea pig and the effect of P. granatum extract loaded CCSM in wound healing was studied. The SEM image showed deep pores in the membrane and also possessed good tensile strength. Wound surface area was reduced prominently in the experimental group with P. granatum extract loaded CCSM when compared to the group with unloaded membrane and the one with no membrane. Punica granatum extract loaded CCSM has antipseudomonal property and supported enhanced epithelial cell proliferation without leaving a scar after wound healing. This has significant therapeutic application in membranous scaffold mediated skin repair and regeneration.

Structurally Complex Organization of Repetitive DNAs in the Genome of Cobia (Rachycentron canadum).

Repetitive DNAs comprise the largest fraction of the eukaryotic genome. They include microsatellites or simple sequence repeats (SSRs), which play an important role in the chromosome differentiation among fishes. Rachycentron canadum is the only representative of the family Rachycentridae. This species has been focused on several multidisciplinary studies in view of its important potential for marine fish farming. In the present study, distinct classes of repetitive DNAs, with emphasis on SSRs, were mapped in the chromosomes of this species to improve the knowledge of its genome organization. Microsatellites exhibited a diversified distribution, both dispersed in euchromatin and clustered in the heterochromatin. The multilocus location of SSRs strengthened the heterochromatin heterogeneity in this species, as suggested by some previous studies. The colocalization of SSRs with retrotransposons and transposons pointed to a close evolutionary relationship between these repetitive sequences. A number of heterochromatic regions highlighted a greater complex organization than previously supposed, harboring a diversity of repetitive elements. In this sense, there was also evidence of colocalization of active genetic regions and different classes of repetitive DNAs in a common heterochromatic region, which offers a potential opportunity for further researches regarding the interaction of these distinct fractions in fish genomes.

Factors affecting toxicity test endpoints in sensitive life stages of native Gulf of Mexico species.

Indigenous species are less commonly used in laboratory aquatic toxicity tests compared with standard test species due to (1) limited availability lack of requisite information necessary for their acclimation and maintenance under laboratory conditions and (2) lack of information on their sensitivity and the reproducibility of toxicity test results. As part of the Natural Resource Damage Assessment aquatic toxicity program in response to the Deepwater Horizon Oil incident (2010), sensitive life stages of native Gulf of Mexico species were evaluated in laboratory toxicity tests to determine the potential effects of the spill. Fish (n = 5) and invertebrates (n = 2) selected for this program include the following: the Florida pompano (Trachinotus carolinus), red drum (Sciaenops ocellatus), spotted sea trout (Cynoscion nebulosus), cobia (Rachycentron canadum), red porgy (Pagrus pagrus), blue crab (Callinectes sapidus), and the common moon jellyfish (Aurelia aurita). Initially in the program, to establish part of the background information, acute tests with reference toxicants (CdCl2, KCl, CuSO4) were performed with each species to establish data on intraspecies variability and test precision as well as identify other factors that may affect toxicity results. Median lethal concentration (LC50) values were calculated for each acute toxicity test with average LC50 values ranging from 248 to 862 mg/L for fish exposures to potassium chloride. Variability between test results was determined for each species by calculating the coefficient of variation (%CV) based on LC50 values. CVs ranged from 11.2 % for pompano (96-h LC50 value) to 74.8 % for red porgy 24-h tests. Cadmium chloride acute toxicity tests with the jellyfish A. aurita had the lowest overall CV of 3.6 %. By understanding acute toxicity to these native organisms from a compound with known toxicity ranges and the variability in test results, acute tests with nonstandard species can be better interpreted and used appropriately when determining risk.

Quality Attributes of Cobia (Rachycentron canadum) Fillets Chilled and Packaged in Modified Atmospheres

The aim of the present work was to evaluate the effects of modified atmospheres packaging (MAP) on cobia (Rachycentron canadum) fillets. The specimens used were filleted and packed in high-density ethylene-vinyl alcohol plastic bags and then submitted to 3 treatments: A (control atmosphere air condition), B (vacuum atmosphere condition) and C (100% CO2 atmosphere condition), B (vacuum) and C (100% CO2). The packaged samples were maintained under cooling temperature of 2 ± 1°C. Samples were submitted to different analysis (TVB-N, pH, TBA, texture, color and microbiology) during the storage period (zero, 1, 7, 14, 21, 30 and 45 days). Samples stored under aerobic conditions (A) showed fast increase of TVB-N and an increase of pH values. The TBA indexes remained below 3.5 mg kg-1 for all treatments and the color patterns varied slightly while the texture analyses varied from 2.05 to 6.61 N. From the results of the chemical and microbiological analyses, it can be concluded that the treatments (B) and (C) presented satisfactory results for the storage test period. MAP treatment (C), different for the other ones, presented discolored fillets with softer texture. Vacuum packing, proved as the best treatment, maintained the best stability condition for chemical, microbiological and sensory characteristics throughout the experiment, extending the shelf life of cobia fillets for 30 days.

Distribution, Abundance and Sustainable Yield of Cobia Rachycentron canadum (Linnaeus 1766) Occurring in Indian Waters

Distribution, Abundance and Sustainable Yield of Cobia Rachycentron canadum (Linnaeus 1766) Occurring in Indian Waters

Growth Performance of Hybrid Striped Bass, Rainbow Trout, and Cobia Utilizing Asian Carp Meal‐Based Aquafeeds

AbstractFish meal sparing is more difficult for nutritionally demanding carnivorous fishes, but economic considerations and the limited supply of fish meal continue to incentivize investigations of alternative protein sources for aquafeeds. A promising alternative to traditional, marine‐origin fish meal is fish meal derived from undesirable freshwater species, such as the invasive Asian carp Hypophthalmichthys spp. To assess the relative value of such ingredients, we evaluated growth performance of juvenile hybrid Striped Bass (White Bass Morone chrysops × Striped Bass M. saxatilis; initial weight, 21.9 ± 0.2 g [mean ± SE]), Rainbow Trout Oncorhynchus mykiss (15.1 ± 0.2 g), and Cobia Rachycentron canadum (57.2 ± 0.5 g) reared for 8 weeks on practical diets containing different levels of menhaden fish meal (MFM), Asian carp meal (CFM), or a 50:50 blend of these ingredients such that 0, 20, 40, or 60% of the estimated digestible protein content was derived from fish meal. Growth performance was generally consistent across taxa, and weight gain tended to increase with fish meal inclusion, regardless of its origin. However, Cobia did perform better on CFM‐based diets, suggesting that MFM or CFM can yield improved performance for some taxa or life stages, but these differences are likely to be marginal in most circumstances. We conclude CFM is a suitable and perhaps lower‐cost alternative to MFM in feeds for carnivorous fishes.

Partial toxicity tests of copper (Cu2+), zinc (Zn2+) and cyanide (CN-) for young cobia fishes (Rachycentron canadum) with 45 day-old

The partial toxicity tests of copper (Cu2+), zinc (Zn2+) and cyanide (CN-) for young cobia fishes with (Rachycentron canadum) 45 day-old were conducted in the Doson station during ten days (yr 2005). These three toxic substances affected strongly the growth of the cobia fish (size and weight), even at the lowest treated concentration. The LC50 values of copper, zinc and cyanide were 0.32 mg/l; upper 1mg/l and 0.049 mg/l, respectively. Based on the calculated results of NOEC and LOEC, we have determined the safe concentrations of these two heavy metals and cyanide for the environmental aquaculture of the cobia fish which were lower than 0.025 mg Cu/l, 0.5 mg Zn/l and 0.005 mg CN/l respectively. The results is also showed that cyanide was the most toxic to Cobia, followed by copper and zinc.

Probiotic effects on cobia Rachycentron canadum larvae reared in a recirculating aquaculture system

Cobia (Rachycentron canadum) is a marine finfish with good potential for mariculture. This study analyzes the effects of probiotic Bacillus spp. on the performance of cobia larvae reared in a recirculating aquaculture system (RAS). Larvae were stocked into two independent RAS for 26 days after hatching. One of the systems (Probiotic treatment) received the addition of a commercial probiotic consisting of B. subtilis, B. licheniformis and B. pumilus directly into the water and by live feed. Survival, final weight and water quality were not affected by probiotics. Results showed larvae of the probiotic treatment demonstrated a greater resistance to salinity stress. Immunohistochemical analysis showed a higher expression of CD4 in probiotic treatment. These results suggest that Bacillus spp. probiotics used in RAS have a potential stimulating impact on immune system differentiation and increases salinity stress resistance of cobia larvae.

Dynamic monitoring of the shelf life of Cobia (Rachycentron canadum): a study on the applicability of a smart photochromic indicator

SummaryTo ensure the marketing of fresh fish‐based products, it is necessary to develop fast methods that assess its freshness in real time. This study therefore evaluated the applicability of a photochromic time–temperature indicator (TTI) to monitor the time and temperature history during the period of validity of the whole fish of the cobia specimen stored in ice. The TTI response was both visibly interpreted as well as adaptable to measurement using suitable equipment. The results showed that the smart indicator activated during 6 s of ultraviolet light showed a similar rate of deterioration of the analysed product visual response, proving to be a dynamic shelf life indicator that can assure consumers the ultimate quality point of the entire cobia easily, cheaply and accurately.

Physical properties of cobia (Rachycentron canadum) surimi: effect of washing cycle at different salt concentrations.

This study aimed to determine the effects of 2-5 wash cycles and the addition of tetrasodium pyrophosphate (TSPP) (0%, 0.05 Surimi% and 0.1% w/w)-with or without the addition of 0.4% calcium chloride (CaCl2)-on the physical properties such as texture, colour, expressible moisture and microstructure of Cobia (Rachycentron canadum) surimi gel. The highest breaking force (484.85g) was obtained with the addition 0.1% TSPP alone on the fifth wash. However, a combination of 0.1 and 0.4% CaCl2 in surimi gels at wash cycle 5 resulted in the highest degree of whiteness (86.8%), as well as total expressible moisture (2.785%) and deformation (17.11mm). The highest surimi gel strength (6,923g.mm) was obtained after three wash cycles with the addition of 0.1% TSPP +0.4% CaCl2. The physical properties of Cobia fish surimi gels were affected by the number of wash cycles and treatments with TSPP and CaCl2.

Unusual Dispersion of Histone Repeats on the Whole Chromosomal Complement and Their Colocalization with Ribosomal Genes in Rachycentron canadum (Rachycentridae, Perciformes)

Rachycentron canadum, the only representative of the family Rachycentridae, has been the focus of biotechnological interest due to its significant potential in marine fish farming. The chromosome set of this species has been widely investigated with respect to the location of genes and multigene families. A FISH analysis was performed using 4 multigene families as probes, represented by 5S and 18S ribosomal genes and histones H2B-H2A and H3. Earlier data suggested that differential replication of heterochromatin could be partially associated with functional genes. Indeed, our results showed that the DNA contained in heterochromatic regions of R. canadum contains 5S and 18S ribosomal genes as well as the gene sequences of histones H2B-H2A and H3, which were colocalized. The distribution of H3 sequences in all heterochromatic regions, except in 13q, could indicate an important evolutionary role for this class of repetitive sequences. Besides, the presence of chromosome regions bearing multifunctional repetitive sequences formed by H2B-H2A/H3/18S rDNA and H2B-H2A/H3/5S rDNA clusters was demonstrated for the first time in fishes. The implications of differential histone gene extension and its functionality in the karyotype of R. canadum remain unknown.

Effects of dietary manganese sources and levels on growth performance, relative manganese bioavailability, antioxidant activities and tissue mineral content of juvenile cobia (Rachycentron canadumL)

This study was conducted to compare the effects of manganese sulphate (Mn-S), glycine manganese(Mn-Gly) and manganese 2-hydroxy-4-(methylthio)butyrate (Mn-HMB) on juvenile cobia, Rachycentron canadum L. Treatments consisted of 0, 2, 4, 8, 16 or 32 mg supplemental Mn kg−1 from Mn-S, Mn-Gly or Mn-MHB. Growth performance, manganese status, antioxidant activities and tissue mineral content were analysed after a 70-day feeding period. Specific growth rate (SGR) increased with feeding 6.29 to 12.65 mg Mn kg−1 diet from the Mn-S or 6.86 to 12.39 mg Mn kg−1 from the Mn-Gly or 6.50 to 8.33 mg Mn kg−1 from the Mn-HMB and then plateaued above these levels. Feed conversion ratio (FCR) show decreasing first and then increased trend. Survival rate (SR) were not affected by the dietary treatments (P > 0.05). Fish fed diets supplemented with manganese at levels of 4–32 mg Mn kg−1 had obviously higher hepatic Mn-SOD activity (P < 0.05); on the contrary, hepatic has lower malondialdehyde (MDA) content (P < 0.05) than fish fed the basal diet. The manganese concentrations of whole body and vertebrae increased with increasing dietary Mn levels from 2–32 mg Mn kg−1 (independent on manganese sources). Dietary Mn supplementation did not significantly influence the copper concentrations of whole body and vertebrae, the zinc concentrations of whole body and liver. Analysis by the broken-line regression of SGR indicated that the optimal dietary Mn requirements in juvenile cobia were 15.42, 11.22 and 10.50 mg Mn kg−1 diet from Mn-S, Mn-Gly or Mn-HMB respectively.

The effects of garlic-supplemented diets on antibacterial activities against Photobacterium damselae subsp. piscicida and Streptococcus iniae and on growth in Cobia, Rachycentron canadum

Abstract Photobacteriosis and streptococcosis are the most threatening diseases in cage-cultured cobia, Rachycentron canadum , due to high mortality of 50–80% and annual outbreaks in Taiwan. Garlic, Allium sativum , has long been known to have broad antibacterial properties. This study aimed to examine the in vitro antibacterial activities of garlic and the effects of dietary garlic on disease resistance against Photobacterium damselae subsp. piscicida and Streptococcus iniae and on growth in cobia. The results revealed the marked inhibitory effect of garlic against both P. damselae subsp. piscicida and S. iniae , and feeding garlic diet significantly conferred resistance to challenge with P. damselae subsp. piscicida or/and S. iniae . Cobia fed garlic powder at doses of 0.5 and 1.5 g/kg b.w. for 28 days produced significantly (p P. damselae subsp. piscicida and higher percent weight gain. Cobia fed garlic powder at a dose of 1.2 g/kg b.w. for 21 days and at doses of 0.4 and 1.2 g/kg b.w. for 28 days provided significant (p S. iniae infection. A diet containing garlic powder at a dose of 1.2 g/kg b.w. for 28 days provided significant (p P. damselae subsp. piscicida plus S. iniae combined infection in cobia.

Purification, characterization and molecular cloning of alpha-2-macroglobulin in cobia, Rachycentron canadum

Alpha-2-macroglobulin (α-2-M) is a broad spectrum protease inhibitor which is abundant in the plasma of vertebrates and several invertebrates. The α-2-M was purified from cobia (Rachycentron canadum) plasma by a four-step procedure: poly ethylene glycol fractionation, affinity chromatography, hydrophobic interaction chromatography and ion exchange chromatography on Fast Protein liquid chromatography system in the present study. It migrated as one protein band with a molecular mass of about 360 kDa in the native state, whereas in SDS-PAGE it was about 180 kDa under non-reducing condition. This result revealed that the native protein was a dimer. In addition, it was cleaved into two different fragments of molecular mass about 93 and 87 kDa when reduced by dithiothreitol (DTT). The anti-protease activity of the purified α-2-M was apparently decreased as temperature elevated above 50 °C. The α-2-M exhibited highest protease inhibitory activity at pH 9. The results indicate that the α-2-M is a heat-labile and alkaline protease inhibitor. The purified α-2-M exhibited more than 50％ protease inhibitory activity against extracellular products (ECP) of Vibrio alginolytius isolated from diseased cobia. It seems that the protease activities in ECP may be affected by the plasma α-2-M. The protease inhibitory activities of cobia plasma or purified α-2-M were decreased when incubated with 10 mM methylamine for 30 min.The α-2-M cDNA consisted of 4611 bp with an open reading frame of 4374 bp had been cloned from cobia liver. This sequence contained thioester domain (GCGEQ) and thirteen predicted N-linked glycosylation sites. In addition, the amino acid sequence of thioester domain and genes of adjacent regions of cobia α-2-M were further compared with sequences of known fish species in GenBank. The unweighted pair group method using arithmetic average (UPGMA) was employed to construct the phylogenetic trees of α-2-M among different fish species (freshwater fish, sea water fish and primitive fish), and all these fish species were then clustered into three groups. The cobia α-2-M was closer to that of sea water fish than that of freshwater fish compared basing on its similarity of amino acid sequence and phylogenetic analysis of the partial gene.

Thyroid gland development in Rachycentron canadum during early life stages

The aim of this study was to describe the ontogeny of thyroid follicles in cobia Rachycentron canadum. Larvae were sampled daily (n=15 - 20) from hatching until 15 dah (days after hatching). Following, larvae were sampled every two days by 28 dah; a new sample was taken at 53 dah. The samples were dehydrated, embedded in Paraplast, and sections of 3 µm were dewaxed, rehydrated and stained with HE and PAS. A single follicle was already present 1 dah and three follicles were found 8 dah. The number of follicles increased up to 19 on 53 dah. The diameter of follicles and follicular cell height were lower 1 dah (6.83 ± 1.00 and 4.6 ± 0.01 µm), but increased from 8 dah (24.03 ± 0.46 µm e 6.43 ± 0.46 µm). From 8 dah, the presence of reabsorption vesicles was observed in the colloid and from the 19 dah some follicles did not present colloid. The early thyroid follicle appearance in cobia larvae as well as the high quantity of follicles without colloid and/or with vesicles even after the metamorphosis, might be the explanation of the fast growth of the cobia.

Partial replacement of fishmeal, poultry by-product meal and soy protein concentrate with two non-genetically modified soybean cultivars in diets for juvenile cobia, Rachycentron canadum

Fishmeal (FM) replacement in diets for intensive aquaculture has become a high priority area for the global aquaculture industry. In this study, a twelve week growth trial was conducted with juvenile cobia (18 g initial weight) to examine the effects of non-genetically modified soybean meals as potential replacement protein sources. Genetically modified (GM) crops and their intended and unintended effects have become major topics of controversy worldwide, with several regions banning their use in food and feeds. Therefore, it is especially critical to develop and evaluate non-GM feedstuffs for use in aquaculture diets where GM products are prohibited as the global aquaculture industry continues its expansion to meet increasing demands. Navita Premium Feed Ingredients (NPFI's) 3010 solvent extracted meal and 3032 cold-pressed cake meal were utilized to replace 50, 60 or 70% and 40, 50, or 60% of FM protein, respectively and were compared to a FM based reference formulation. None of the experimental diets performed significantly different from the reference diet in terms of weight gain (WG) or specific growth rate (SGR). However the 3010 50% diet performed significantly better than the 3032 50 and 60% diets in regard to WG, SGR, and protein efficiency. There were no significant differences between the seven diets at the conclusion of the trial in regard to their effects on filet quality as determined by organoleptic testing. These two non-GM soybean protein sources appear to be valuable FM replacement options for juvenile cobia, with none of the typical indicators of intestinal enteritis developing as has been observed in various other teleost species when high quantities of commodity soybean meal have been utilized.

Genetic characteristics of Streptococcus dysgalactiae isolated from cage cultured cobia, Rachycentron canadum (L.).

Disease outbreaks occurred during 2007-2013 in Taiwan with 2.5-10% mortality among the cage cultured cobia, Rachycentron canadum (L.), characterized by the presence of polyserositis, pericarditis and peritonitis. The micro-organisms isolated from internal organs were Gram-positive cocci. The isolates were confirmed as Streptococcus dysgalactiae by a polymerase chain reaction assay that yielded the expected specific 259 bp amplicon. Additionally, partial sequence of the 16S-23S rDNA intergenic spacer region of the GCS strain isolates from fish was also compared and produced 100% sequence identity with S. dysgalactiae (GenBank accession number AB252398). The genetic characterization was then determined by pulsed-field gel electrophoresis (PFGE) analysis. Based on PFGE, the Apa I or Sma I digestion patterns of chromosomal DNA of these isolates were grouped into three main clusters. Taiwanese strains were divided into two clusters, and the tet(M) gene was detected in cluster 1 (pulsotypes: A1-A2 and S1-S3), but not in cluster 2 strains (pulsotypes: A3-A4 and S4-S5). Three Japanese strains from amberjack, Seriola dumerili (Risso), were grouped into cluster 3 (pulsotypes: A5-A7 and S6-S8) and displayed no mortality to cobia in the challenge experiment. Conversely, Taiwanese strains from cobia and snubnose pompano, Trachinotus blochii (L.), displayed a mortality rate of 50-87.5% in cobia.

Effects of supplemental coated or crystalline methionine in low-fishmeal diet on the growth performance and body composition of juvenile cobia Rachycentron canadum (Linnaeus)

We evaluated the effects of supplemental coated and crystalline methionine (Met) on the growth performance and feed utilization of juvenile cobia (Rachycentron canadum Linnaeus) in a 60-d feeding trial. Fish groups were fed one of six isonitrogenous and isolipidic diets: 1) fishmeal control; 2) un-supplemented experimental (low-fish-meal diet deficient in Met); or 3) one of four Met diets supplemented with crystalline L-Met, cellulose-acetate-phthalate coated L-Met, acrylic-resin coated L-Met, or tripalmitin-polyvinyl alcohol coated L-Met. The test diets were fed to triplicate groups of cobia (initial body weight 5.40±0.07 g) twice a day. The weight gain and specific growth rate of the fish fed the RES diet were highest among the Met-supplemented groups and were 23.64% and 7.99%, respectively, higher than those of the fish fed with the un-supplemented experimental diet (P<0.05). The protein efficiency ratio of the fish fed the MET diet was significantly higher than that of the fish fed the un-supplemented experimental diet and the fish in the other methionine supplementation groups (P<0.05). Our results suggest that supplementation of crystalline Met in low-fish-meal diets promotes the growth performance of juvenile cobia.

Characterization of catalytic efficiency parameters of brain cholinesterases in tropical fish.

Brain cholinesterases from four fish (Arapaima gigas, Colossoma macropomum, Rachycentron canadum and Oreochromis niloticus) were characterized using specific substrates and selective inhibitors. Parameters of catalytic efficiency such as activation energy (AE), k(cat) and k(cat)/k(m) as well as rate enhancements produced by these enzymes were estimated by a method using crude extracts described here. Despite the BChE-like activity, specific substrate kinetic analysis pointed to the existence of only acetylcholinesterase (AChE) in brain of the species studied. Selective inhibition suggests that C. macropomum brain AChE presents atypical activity regarding its behavior in the presence of selective inhibitors. AE data showed that the enzymes increased the rate of reactions up to 10(12) in relation to the uncatalyzed reactions. Zymograms showed the presence of AChE isoforms with molecular weights ranging from 202 to 299 kDa. Values of k(cat) and k(cat)/k(m) were similar to those found in the literature.

More Judicious Use of Fish Oil in Cobia Feeds: I. Assessing the Relative Merits of Alternative Lipids

AbstractLimited availability and high prices underscore the need to use fish oil more judiciously in aquafeeds. Most alternative lipids contain little to no n‐3 long‐chain (LC) polyunsaturated fatty acids (PUFAs). If alternative lipids are fed exclusively, growth performance may be impaired and tissue fatty acid composition may be altered in fish such as the Cobia Rachycentron canadum. Alternative lipids that are rich in saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) may increase the efficiency of LC‐PUFA metabolism and may limit or attenuate the tissue LC‐PUFA loss associated with fish oil sparing. Cobias (weight [mean ± SE] = 77.4 ± 0.2 g) were fed diets containing either fish oil (control) or a 50/50 blend of fish oil and standard soybean oil, partially hydrogenated soybean oil, fully hydrogenated soybean oil, pork lard, or beef tallow. After 8 weeks, the feed conversion ratio (mean ± SE = 1.56 ± 0.04), weight gain (180 ± 6%), and specific growth rate (1.83 ± 0.04% of body weight/d) were equivalent among groups. Dietary fatty acid profiles influenced tissue composition; fatty acid profiles of control fish were more similar to those of fish that received higher levels of SFAs and MUFAs than to those of fish that were fed higher levels of C18 PUFAs. The SFA‐ and MUFA‐rich lipids, such as fully hydrogenated soybean oil and beef tallow, may be useful in reducing the fish oil quantities needed in Cobia feeds while maximizing fillet LC‐PUFA content.