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Two specimens of the Lessepsian migrant, the Mangrove red snapper Lutjanus argentimaculatus are reported from the Mediterranean coast of Israel. L. argentimaculatus was first recorded in the Mediterranean in 1979 by a single specimen. Over three decades later and only in the last two years four specimens, including the two reported herein, were recorded. This pattern strongly suggests that L. argentimaculatus has established a sustainable population in the Mediterranean. [ABSTRACT FROM AUTHOR]

Documenting bacteria present in healthy individuals forms the first step in understanding the effects of microbial manipulation in aquaculture systems. Among the commensal microflora, gut microbiota has attracted extensive attention owing to their role in host metabolism and health maintenance. Basic knowledge on normal gut microbes within a particular host species is thus essential to determine how successfully these microbes can be manipulated and engineered for sustainable aquaculture systems. In spite of the good aquaculture potential of Mangrove red snapper, Lutjanus argentimaculatus, the information on microbial communities associated with the gut of this fish, and their contribution towards digestive efficiency and disease resistance is scarce. Therefore, an attempt was made to elucidate the abundance and diversity of cultivable gut microbes of wild caught L. argentimaculatus along with their digestive exoenzyme profiles and prohibitory effect against fish pathogens. Results on abundance showed similar gut bacterial loads as that of other marine fish imposing the less contribution of microflora to the volume of gut materials in fish. Eleven distinct bacterial species including two proposed novel vibrios were identified. An incidental observation of Morganella morganii throughout samples is an alarming signal, emphasizing the need for immediate de-gutting to avoid histamine intoxication. Abundance of digestive enzyme producers and excellent enzymatic potential of some isolates suggested the contribution of digestive enzymes may supplement to the symbiosis between gut flora and host and the information is of interest to aquaculture nutritionists/commercial industries. Interestingly, some isolates demonstrated estimable co-aggregation with aquatic pathogens, indicating their involvement in disease resistance and the results correlated well with gut microbial diversity. These findings highlight the significant role of gut microbes towards nutritional physiology and disease resistance of this aquaculture candidate in natural ecosystem. The culturable microbiota profiles of wild fish generated in the study can be applied for measuring the quality of husbandry routines in aquaculture facility of this marine fish. Overall, the present study fetches insights on the gut microbiome of healthy L. argentimaculatus which forms a platform for follow-up studies. The study may also help in the development of “functional” fish feeds for L. argentimaculatus . The investigation also demonstrated some potential digestive enzyme-producing isolates having probiotic applications in commercial aquaculture. [ABSTRACT FROM AUTHOR]

Mangrove Red Snapper (Lutjanus argentimaculatus) is a large, palatable fish that has become increasingly valuable for aquaculture in South East Asia. Unfortunately, the bulk of current mariculture of L. argentimaculatus depends almost entirely on fingerlings collected from the wild, since hatchery-raised fry are regarded as inferior by fishermen. Wild Mangrove Red Snapper spawn on offshore reefs, but their larvae occupy coastal lagoons and estuaries. In this study, we examine some of the factors (habitat structure and salinity) associated with the natural recruitment habitat of L. argentimaculatus to determine whether they might play a role in the perceived superiority of wild-caught fry. We found statistically significant relationships between survival and salinity, and between somatic growth and habitat structure, but no interaction between the factors. Juvenile L. argentimaculatus survive best at moderate (17ppt) salinities, with fresher water (10ppt) providing better outcomes than more saline (25ppt) conditions. We found also that juveniles grew best when provided with hard, complex structures (rock piles and mangrove roots), rather than in tanks without such structures. Here, we have demonstrated two simple environmental factors that improve survival and growth of juvenile L. argentimaculatus and may provide a substantial boost to the performance of hatcheryreared fish. [ABSTRACT FROM AUTHOR]

A feeding trial was undertaken to develop a low fishmeal practical diet for mangrove red snapper (Lutjanus argentimaculatus) by replacing 60% fishmeal (FM) protein with either soybean meal (SM) or peanut meal (PM), and 10% fish soluble (FS) or krill meal (KM) supplementation. Seven isonitrogenous (crude protein: 40% dry matter) and isolipidic (crude lipid: 9% dry matter) diets were prepared (FM100, FM40+SM, FM40+SM+FS, FM40+SM+KM, FM40+PM, FM40+PM+FS, FM40+PM+ KM. Triplicate groups of fish (initial body weight: 1.46±0.02 g, mean ± S.E.M) were stocked in 150L circular fiberglass tanks at a density of 18 fish per tank. Results showed no significant (p>0.05) differences in final body weight (FBW) values or weight gain (WG) between fish fed the FM100 diet, and those fed FM40+SM, FM40+SM+FS and FM40+SM+KM diets. For fish fed the FM40+PM diet, WG was significantly lower when compared with fish fed the other experiment diets. Supplementation of 10% FS or KM improved growth parameters of fish fed diets containing PM. Feed efficiency (FE), protein efficiency ratio (PER) and protein productive value (PPV) showed similar tendencies to the growth indices. No significant differences in feed intake (FI) were observed among all the different dietary treatments. Significant lower whole-body protein and lipid content were recorded in fish fed FM40+PM diet. The present study indicates that 60% of fishmeal protein can be replaced by soybean meal or by a mixture of peanut meal and 10% FS or KM without affecting growth performance of Lutjanus argentimaculatus. [ABSTRACT FROM AUTHOR]

The effects of climate change are difficult to predict for many marine species because little is known of their response to climate variations in the past. However, long-term chronologies of growth, a variable that integrates multiple physical and biological factors, are now available for several marine taxa. These allow us to search for climate-driven synchrony in growth across multiple taxa and ecosystems, identifying the key processes driving biological responses at very large spatial scales. We hypothesized that in northwest (NW) Australia, a region that is predicted to be strongly influenced by climate change, the El Ni~no Southern Oscillation (ENSO) phenomenon would be an important factor influencing the growth patterns of organisms in both marine and terrestrial environments. To test this idea, we analyzed existing growth chronologies of the marine fish Lutjanus argentimaculatus, the coral Porites spp. and the tree Callitris columellaris and developed a new chronology for another marine fish, Lethrinus nebulosus. Principal components analysis and linear model selection showed evidence of ENSO-driven synchrony in growth among all four taxa at interannual time scales, the first such result for the Southern Hemisphere. Rainfall, sea surface temperatures, and sea surface salinities, which are linked to the ENSO system, influenced the annual growth of fishes, trees, and corals. All four taxa had negative relationships with the Ni~no-4 index (a measure of ENSO status), with positive growth patterns occurring during strong La Ni~na years. This finding implies that future changes in the strength and frequency of ENSO events are likely to have major consequences for both marine and terrestrial taxa. Strong similarities in the growth patterns of fish and trees offer the possibility of using tree-ring chronologies, which span longer time periods than those of fish, to aid understanding of both historical and future responses of fish populations to climate variation. [ABSTRACT FROM AUTHOR]

This study provides the first assessment of fish associations with oil and gas structures located in deep water (85-175 m) on Australia's north-west continental shelf, using rare oil industry video footage obtained from remotely operated vehicles. A diverse range of taxa were observed associating with the structures, including reef-dependent species and transient pelagic species. Ten commercially fished species were observed, the most abundant of which was Lutjanus argentimaculatus, with an estimated biomass for the two deepest structures (Goodwyn and Echo) of 109 kg. [ABSTRACT FROM AUTHOR]

The effects of several dietary protein levels on the growth, feed conversion, body composition and diet digestibility of juvenile Lutjanus argentimaculatus (body weight 12.3 g) were examined. Seven isolipidic (7.4%) diets were formulated to contain graded levels of protein (28-58%) with dietary energy ranging from 19.7 to 21.5 kJ g−1. Diets were distributed to triplicate groups of fish thrice a day at ration of 2% body weight for 90 days. Growth, feed conversion, protein utilization and digestibility of nutrients increased with increasing dietary protein level up to 43%, after which no significant improvement was observed. Digestibility of dry matter and energy showed a concomitant increase with the reduction in dietary wheat meal, attaining maximal values with high protein diets. No significant differences were detected in moisture, protein, lipid and ash content of whole fish or body organs as dietary protein increased. The mesenteric fat, hepato- and viscerosomatic indices decreased with increasing protein level. The cholesterol, triglycerides and haematocrit values were similar among treatments, except that high levels of plasma lipids were recorded above 43% protein diet. The use of a practical diet containing 43% protein is appropriate for the growth of L. argentimaculatus juveniles under the experimental conditions of the present study. [ABSTRACT FROM AUTHOR]

Migrational patterns of mangrove jack Lutjanus argentimaculatus were studied in a mangrove estuary in Trang province, Thailand, using ultrasonic telemetry. Ultrasonic coded transmitters were surgically implanted in 18 fish and 16 of them were subsequently monitored by nine fixed receivers installed along Sikao Creek estuary in June and November 2006. Due to technical limitations all of the individuals were released in the middle of the creek. Their movements were monitored for a period of up to 1 month, the data being used to describe short term migration of juvenile Lutjanus argentimaculatus in the creek and to find possible environmental cues for the observed movements. All of the individuals showed a tide related movement pattern, suggesting foraging in the small mangrove channels and/or mangrove forest during high tides. 50% of the fish left the study area for the open coast area within a short time following release, indicating that a part of juvenile L. argentimaculatus may move in between estuarine habitats instead of being site attached. As the fish were reared in fish cages for a certain period of time before the study this behavior could partly be explained by the time spent in captivity. It was found that L. argentimaculatus showed higher movement activity during night high tides possibly explained by an increased availability of the sough after food items. [ABSTRACT FROM AUTHOR]

Abstract: The study describes the pathological manifestations of the acanthocephalan, Tenuiproboscis sp. in the mangrove red snapper, Lutjanus argentimaculatus, a highly valued food fish along the southwest coast of India. The fish collected from Calicut, Cochin and Kannur harboured the acanthocephalan parasite, Tenuiproboscis sp. with up to 100% prevalence. Heavy infections with the parasites were observed in the posterior region of the intestine, almost blocking the lumen. At the site of parasite attachment, the surface of the intestine appeared thickened and the mucosal epithelium showed compression and abrasion. Intestinal folds were eroded along with thickening of lamina propria. The presoma of the parasites pierced the mucosal epithelium, lamina propria, muscle layers and serosa, reaching the peritoneal cavity, surrounded by a tunnel with collagenous fibers and granulocytes. Inflammation, granular tissue formation, connective tissue proliferation and associated host immune reactions were evident. Though the worms substantially damaged the architecture of the intestinal tissues, no apparent ill effects on the general health/condition of the fish were observed. The parasite was also recovered from Epinephelus malabaricus and Lates calcarifer. This is the first report of Tenuiproboscis sp. from L. argentimaculatus, E. malabaricus and L. calcarifer. [Copyright &y& Elsevier]

Abstract: Sperm cryopreservation of red snapper (Lutjanus argentimaculatus) is essentially unexplored, although many species of the Lutjanidae family are considered to be high-value commercial species. The objective of this study was to develop a species-specific cryopreservation protocol for red snapper (L. argentimaculatus) sperm by optimizing cryoprotectants and cooling rates in the cryopreservation procedure. Ten cryoprotectants at four concentrations and two freezing protocols were examined in two separate experiments. In the first experiment, toxicity studies of dimethyl sulfoxide (DMSO), glycerol, propylene glycol (PG), ethylene glycol (EG), formamide, methanol, ethanol, sucrose, trehalose, and dimethylacetamide (DMA) on sperm motility were performed. Semen diluted 1:1 in Ringer solution were exposed to cryoprotectants at four final concentrations of 5%, 10%, 15%, or 20% for periods of 10, 20, 30, 40, 50, 60, 90, and 120min at room temperature (25°C). The cryoprotectants and concentrations that showed the least toxic effect on sperm motility were selected for cryopreservation trials. In the second experiment, selected cryoprotectants were then assessed for freezing capacity of sperm as follows: DMSO 5% and 10%, PG 5% and 10%, EG 5% and 10%, ethanol 5%, and methanol 5%. Semen was diluted 1:1 in Ringer solution and equilibrated with selected cryoprotectants for 10min at room temperature. Sperm were frozen in a controlled-rate programmable freezer at four cooling rates of 3, 5, 10, and 12°C/min from an initial temperature of 25°C to final temperatures of −40 or −80°C before plunging into liquid nitrogen. Sperm equilibrated in 10% DMSO and cooled at a rate of 10°C/min to a final temperature of −80°C had the highest motility (91.1±2.2%) and viability (92.7±2.3%) after thawing. The fertilization rate of frozen-thawed sperm (72.4±2.4%) was not different (P>0.05) from that of fresh sperm (75.5±2.4%). This study apparently represents the first reported attempt for cryopreservation of L. argentimaculatus sperm. [Copyright &y& Elsevier]

The effects of several feeding levels (1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4% and 4.5% of body weight per day, BW day−1) on the growth, feed efficiency and body composition of juvenile Lutjanus argentimaculatus (body weight 27.1 g) were examined. Fish were fed a test diet (40% protein, 18.4% lipid and 13.4 kJ g−1) for 75 days in three equal meals. Weight gain and specific growth rate increased with increasing feeding level up to 2.5% BW day−1, after which no significant improvement in growth was observed. The feed efficiency, protein efficiency ratio, retention of protein and digestibility of nutrients did not differ for fish fed 1–2.5% BW day−1, but decreased significantly when feeding levels were increased above 3% BW day−1. The chemical compositions of whole fish or body organs were significantly affected by the feeding level. The condition factor, mesenteric fat, hepato- and viscerosomatic indices were higher in fish fed 2.5–4.5% BW day−1. The cholesterol, triglycerides and haematocrit values were similar among treatments, except that high levels of plasma lipids were recorded in fish fed at 2.5% BW day−1. Taking into consideration the growth, feed efficiency and body composition data attained in this study, a feeding level of 2.5% BW day−1 is recommended for juvenile L. argentimaculatus weighing between 27 and 140 g. [ABSTRACT FROM AUTHOR]

A feeding trial was conducted for 75 d to evaluate the nutritive value of a mixture of animal by-products (MAB) as a possible protein source in diets for juvenile mangrove red snapper, Lutjanus argentimaculatus (mean initial body weight, 30 g). Fish were fed one of five isonitrogenous diets (40% crude protein) replacing 0, 25% (MAB25), 50% (MAB50), 75% (MAB75) and 100% (MAB100) of fish meal protein with similar percentages of MAB. The MAB consisted of 25% cow liver meal, 20% leather meal, 20% meat and bone meal, 15% blood meal, 10% APC (poultry feather meal), 8% poultry manure dried, 1.5% choline and 0.5% chromic oxide. After 75 d of feeding, fish fed with diets MAB50, MAB75 and MAB100 exhibited significantly lower growth performance than that of fish fed with control and MAB25 diets. The optimum level of MAB was estimated to be 23%. Replacement of fish meal by MAB23% showed the following performance: maximum weight gain, 510%; SGR, 2.39% and FCE, 2.83%. The MAB substitution up to 75% of fish meal protein in diets did not show differences in apparent protein digestibility (83.6% for MAB25, 79.2% for MAB50, 78.7% for MAB75) compared with control (83.4%), whereas in MAB100 group digestibility (65.3%) was significantly lower than in other groups. The apparent phosphorus absorption of test diet groups was significantly higher (37.1% for MAB25, 28.5% for MAB50, 55.6% for MAB75 and 54.5% for MAB100) than that of control (11.2%). The levels of protein and ash in the whole body, carcass and viscera increased as MAB substitution in diets increased, whereas lipids and moisture remained consistent among all treatment groups. These results showed that approximately 23% of fish meal protein could be replaced by a mixture of animal by-products for juvenile snapper growing from 30 g to 167 g in 75 d without compromising growth performance and feed efficiency. [ABSTRACT FROM AUTHOR]

A feeding trial was conducted in a recirculating water system to investigate the effects of dietary protein levels on growth, feed utilization, hepatosomatic index and liver lipid deposition of juvenile red snapper, Lutjanus argentimaculatus (average initial wet weight 8.0 ± 0.39 g and total length 3.14 ± 0.3 cm). In the experiment, six fishmeal-based diets were formulated to contain various protein levels (20% to 45% in 5% increments), with dietary energy ranging from 2210.7kJ lOOg to 2250.2kJlOOg dry matter. The protein to energy ratios of diets ranged from 8.58 mg protein kJ−1 to 20.03 mg protein kJ−1. Diets were fed for 90d to triplicate groups of fish stocked in 0.128m3 seawater tanks, 25 individuals each. The daily ration of 2% wet body weight was offered to the fish thrice a day. The fish at the end of the study had more than ten-fold (77.0g) increase in weight compared to the initial (8.0g). Fish fed diets of 40% and 45% protein produced significantly ( P<0.05) higher weight gain of 77.2g and 76.5g, and specific growth rate (SGR) of 2.65% and 2.62% than those of 67.0 g and 68.3g, and 2.49% and 2.51% of the other diets. The broken-line regression of SGR against dietary protein level yielded an optimum dietary protein requirement of 42.6% ( Y=−1.6295 + 0.1114 X 2, P<0.05). Survival remained 100% among groups. Feed conversion ratio decreased from 0.45 for fish fed 20% dietary protein to 0.35 for fish fed 45% dietary protein. Nitrogen intake increased with an increase in dietary protein, which in turn resulted in an increase in nitrogen gain of fish whole body. Fish fed 40% and 45% protein diets showed higher ( P<0.05) nitrogen gain (0.27g and 0.26g) than those (0.23g and 025g) fed all other diets. Gross energy intake (GEI) in fish fed 45% protein was lower (600.67kJ) than that (607.97 kJ) of 40% protein diet, though the differences were not statistically significant ( P>0.05); GEI ranging from 677.31 kJ to 663.20 kJ at remaining four diets (20% to 35% protein) did not appear to differ significantly ( P>0.05). The highest energy gain of 518.33 kJ was obtained with fish fed 40% protein, resulting in the highest energy retention efficiency of 85.26%. The hepatosomatic index of fish fed diets of 20%, 25%, 30% and 35% protein were significantly ( P<0.05) higher (2.09% to 2.57%) than those (1.44% and 1.41%) of fish fed diets containing 40% and 45% protein. Liver lipid contents decreased from 8.72% to 7.0% in fish fed dietary protein of 20% to 45% in 5% increments. Results suggest that the diet containing 40% to 42.6% protein with a P/E ratio of 17.6 mg protein kJ−1 is required for good growth of L. argentimaculatus weighing between 8.0 g and 85.2 g under the culture conditions of the present study. [ABSTRACT FROM AUTHOR]

Outbreaks of heavy infestation by the parasitic dinoflagellate Amyloodinium ocellatum in hatchery-reared milkfish (Chanos chanos) and mangrove red snapper (Lutjanus argentimaculatus) caused 100% mortality events in hatcheries in the Philippines. Parasites were recorded on the body surface in 14-day-old milkfish fry and on both skin and gills in 2-month-old snapper. Trophonts of A. ocellatum caused local erosions of fish skin and degeneration of epithelial cells at the sites of the parasite''s attachment to the body surface. Separation and hyperplasia of gill epithelium and fusion of secondary lamellae at the distal parts of the gill filaments were common. High pathogenicity of A. ocellatum to fish may be attributed to the severe alterations of the fish gills, the disruption of the host''s skin, and feeding of trophonts on hosts'' epithelial cells. In-vivo treatments of A. ocellatum-infested snapper with a 1 h freshwater bath and 200 ppm H2O2 showed promising results. This is the first report of A. ocellatum infestation in milkfish and mangrove red snapper in the Philippines. [Copyright &y& Elsevier]

A practical broodstock diet (39% protein, 8.6% lipid) was formulated for the mangrove red snapper as part of a project to ensure consistent production of good quality eggs and larvae through broodstock nutrition. Reproductive performance of mangrove red snapper broodstock fed practical diet (n=14 females) was enhanced in comparison to those fed raw fish (n=12 females). Broodstock fed practical diet had total egg production of 82.34 million from 68 spawns for two spawning seasons while broodstock fed raw fish produced 77.64 million eggs from 66 spawns. Mean percent of egg viability, hatching rates and percent of normal larvae did not vary between the two groups. However, broodstock fed the practical diet had higher mean cumulative survival rate of eggs to normal larvae (40.4%) than that of broodstock fed raw fish (35.2%). Also, survival activity index (4.08) of broodstock fed practical diet was higher than that of broodstock fed raw fish (2.97). The results clearly indicate the improvement of reproductive performance of mangrove red snapper fed practical diet. Further studies should focus on the specific nutrients that can ensure consistent production of high quality eggs and larvae of the mangrove red snapper to support its aquaculture. [Copyright &y& Elsevier]

Di-n-butyl phthalate, one of the most easily detected pollutants of phthalate esters in the environment, has been added to the priority list of hazardous substances by many countries. As one of low molecular weight phthalates, Di-n-butyl phthalate may have a great adverse potency on various aquatic organisms. In this study, the juvenile red snapper, Lutjanus argentimaculatus , was exposed to the concentrations of Di-n-butyl phthalate (20 μg L−1, 100 μg L−1 and 500 μg L−1) for 15 days. EROD activities and CYP1A levels were measured in liver and gill tissues. In gills, the similar effect has been found to inhibit or induce EROD activities and CYP1A levels, and there existed a good correlation between them. Whereas in the case of the liver, a moderate correlation was observed between EROD activities and CYP1A levels, which was mainly due to the inhibited EROD activities and the CYP1A levels with no significant difference by day 15. In conclusion, this study revealed the similar and different effects of cytochrome P450 enzymes on fish in the time-, concentration-, and tissue-dependent Di-n-butyl phthalate exposure. Furthermore, as the adverse effects indicated between CYP1A levels and EROD activities, metabolic mechanisms of phthalates in different tissues should be highly emphasized in future studies. Di-n-butyl Phthalate Produces Tissue-specific Toxic Effects of Cytochrome P450 and Xenobiotic Metabolism in juvenile red snapper. Unlabelled Image • CYP1A-induced toxicity effect of DBP on Lutjanus argentimaculatus was studied. • Effect of EROD activities and CYP1A levels showed obvious tissue-specificity. • Tissue-specificity indicated the different xenobiotic metabolism between gill and liver. • Valuable biomarkers should not only focus on the target organ, but also the main metabolic organ in future studies. [ABSTRACT FROM AUTHOR]