Lutjanus Argentimaculatus Research Articles

Macro‐ and microscopic morphology of the flank scales of families Lutjanidae and Serranidae from the Persian Gulf Coral Reefs (Teleosts: Perciformes)

AbstractMacro‐ and microscopic characteristics of flank scales for 12 species were investigated from the Persian Gulf Coral Reefs. In Lutjanus argentimaculatus and L. russellii (family Lutjanidae), the scales of different flank regions were not different, while four characters showed variation in the scale of L. lutjanus i.e., scale shape (pentagonal, hexagonal and square), anterior margin (waved, scalloped and smooth), focus shape (circular and oblong) and focus position (postero‐central and central), displayed variation. Scale type (ctenoid) and posterior margin (transforming ctenii) did not show variation and could be considered to be specific in this family. In Epinephelus chlorostigma (family Serranidae), the scales of flank regions did not display variation, while in E. areolatus, E. diacanthus and E. radiates, the scales showed considerable variation. The most variable characters were scale shape, posterior margin and focus shape. Therefore, in fish systematics studies on the base of scale, it is particularly important to compare scales from the same flank regions. Also, some criteria such as size‐dependent alternation, ontogenetic changes and variation between flank regions, should be considered. This study supports the potential of scale morphology to help for the understanding of fish diversity in the coral reef ecosystem.

Growth Performance of the Mangrove Red Snapper (Lutjanus argentimaculatus) in Freshwater Pond Comparing Two Stocking Densities and Three Feed Types

The mangrove red snapper Lutjanus argentimaculatus (Forsskål 1775) is a high value, euryhaline marine fish with potential as a species for freshwater aquaculture. This study evaluated the growth and cost efficiency of the species in a freshwater pond in two experiments with three replications: (a) comparing stocking densities: (1) 0.5; (2) 1; and (3) 3 fish fish•m-2 reared for six months fed three times a day with trash fish to apparent satiation; and (b) comparing feed types: (1) trash fish; (2) moist diet; and (3) formulated dry pellet at a stocking density of 1 fish•m-2 fed to apparent satiation three times a day for seven months. The stocking density (SD) experiment showed significantly higher weight gain, absolute growth and specific growth rate (P<0.05) in 0.5 fish•m-2 SD (184.9 g; 1.04 g•day-1; 2.50%/day) than 3 fish•m-2 SD (172.7 g; 0.96 g•day-1; 2.38 %•day-1). No significant difference was detected between 0.5 fish•m-2 SD and 1 fish•m-2 nor between 1 fish•m-2 and 3 fish•m-2 (P>0.05). Survival rate (SR) and feed conversion ratio (FCR) were not statistically different between treatments (P>0.05), which ranged from 78% to 92% and 5.0 to 5.9, respectively. Cost analysis showed high net returns for 1 and 3 fish•m-2 SD but low in 0.5 fish•m-2 SD. The feeding experiment study showed that feed types significantly affected weight gain, SGR, and SR (P<0.05). Snappers fed with trash fish attained significantly higher mean absolute growth (298.2 g) and SGR (1.81%/day) than those fed moist feeds (232.8 g and 1.61%/day, respectively) and formulated feeds (236.1 g and 1.51%/day, respectively). The survival rate was significantly higher in snappers fed trash fish (93.33%) and dry pellets (94.00%) than fed moist feeds (81.34%). FCR in trash fish, moist and dry pellet treatment was 6.4, 6.3, and 2.7, respectively. Cost analysis showed high net returns for trash fish and formulated pellet fed snappers but low in moist diet feed treatment. Cost-benefit analysis showed the feasibility of mangrove red snapper for freshwater aquaculture at a recommended stocking density of 1 to 3 fish•m-2 using trash fish, moist diet, or formulated dry pellet.

Metabarcoding of Fish Larvae in the Merbok River Reveals Species Diversity and Distribution Along its Mangrove Environment.

The Merbok River (north-west of Peninsular Malaysia) is a mangrove estuary that provides habitat for over 100 species of fish, which are economically and ecologically important. Threats such as habitat loss and overfishing are becoming a great concern for fisheries conservation and management. The identification of larval fish in this estuarine system is important to complement information on the adults. This is because the data could inform the spawning behaviour, reproductive biology, selection of nursery grounds and migration route of fish. Such information is invaluable for fisheries and aquatic environmental monitoring, and thus for their conservation and management. However, identifying fish larvae is a challenging task based only on morphology and even traditional DNA barcoding. To address this, DNA metabarcoding was utilised to detect the diversity of fish in the Merbok River. To complete the study, the fish larvae were collected at six sampling sites of the river. The extracted larval DNA was amplified for the Cytochrome Oxidase subunit 1 (COI) and 12S ribosomal RNA (12S rRNA) genes based on the metabarcoding approach using shotgun sequencing on the next-generation sequencing (NGS) Illumina MiSeq platform. Eighty-nine species from 65 genera and 41 families were detected, with Oryzias javanicus, Oryzias dancena, Lutjanus argentimaculatus and Lutjanus malabaricus among the most common species. The lower diversity observed from previous morphological studies is suggested to be mainly due to seasonal variation over the sampling period between the two methods and limited 12S rRNA sequences in current databases. The metabarcode data and a validation Sanger sequencing step using 15 species-specific primer pairs detected three species in common: Oryzias javanicus, Decapterus maruadsi and Pennahia macrocephalus. Several discrepancies observed between the two molecular approaches could be attributed to contaminants during sampling and DNA extraction, which could mask the presence of target species, especially when DNA from the contaminants is more abundant than the target organisms. In conclusion, this rapid and cost-effective identification method using DNA metabarcoding allowed the detection of numerous fish species from bulk larval samples in the Merbok River. This method can be applied to other sites and other organisms of interest.

Crabs assimilating cellulose materials drive the detritus food chain in a mangrove estuary

The low digestibility of cellulose-rich detritus in primary consumers has been considered to limit its incorporation by higher level consumers. A recent study revealed, however, that the sesarmid crab Parasesarma bidens, which is a dominant benthic consumer in East Asian mangrove forests, possesses high cellulase enzyme activity enabling the species to efficiently digest and assimilate refractory detritus. To elucidate whether P. bidens acts as a trophic intermediate facilitating the incorporation of mangrove detritus into the food chain, the food habits of benthivorous fishes within a subtropical mangrove estuary were investigated. Stomach content analyses indicated that crabs, especially P. bidens, made a large contribution to the diets of the fishes examined, including the snapper Lutjanus argentimaculatus and the seabream Acanthopagrus sivicolus, which were both common at the study site. Furthermore, carbon and nitrogen stable isotope analyses revealed that mangrove detritus contributed significantly to all fish species examined, due to their consumption of P. bidens. These findings suggested that the detrital trophic pathway, via crabs with greater ability to digest/assimilate cellulose materials, plays an integral part in maintaining food chain structures in mangrove ecosystems.

Ecopath modelling approach for the impact assessment of a small-scale coastal aquaculture system in Goa, India

In this study, the ecological impacts of introduction of cage aquaculture employing small cages integrating shellfish and finfish in coastal water bodies of Goa, situated in the west coast of India were analysed using Ecopath with Ecosim model. A multispecies cage aquaculture system incorporating Lutjanus argentimaculatus, Etroplus suratensis and Perna viridis was established in an estuarine ecosystem. The Ecopath model identified 12 functional groups starting from detritus (trophic level=1) to large benthic carnivores (trophic level=3.72). The ecosystem statistics such as total system throughput (8672 g m-2 year-1), gross efficiency (0.001), primary production/respiration (1.4), net system production (1028.2 g m-2 year-1) and system omnivory index (0.26) indicated that the ecosystem was highly productive and in a developing stage. With a medium rate of recycling (Finn’s Cycling Index=11.7%), high system throughput, high system overhead (79%) and moderate omnivory index (0.26), the food web was found to be immature having an organized trophic network with high production. Simulations of the various expanding scenarios for the cage culture within the ecosystem were explored using Ecosim. A scenario in which two cages each for pearlspot and red snapper and 20 mussel ropes was identified as a sustainable solution without sacrificing the threshold biomass for the functional groups of fish species [WU1] . The study provided useful insights and methodology towards assessing aquaculture in coastal ecosystems in terms of ecosystem structure and function.

Retroporomonorchis pansho n. g., n. sp., an unusual monorchiid trematode exploiting an atypical host.

The Monorchiidae Odhner, 1911 are well represented in tropical and subtropical marine fishes worldwide but rarely reported from the Lutjanidae, an important family of tropical fishes that prey mainly on demersal fishes, decapods and cephalopods. Here, we report the first monorchiid from a lutjanid in Australian waters, Retroporomonorchis pansho n. g., n. sp. in Lutjanus fulvus (Forster), off Lizard Island on the northern Great Barrier Reef. It is morphologically and phylogenetically distinct among known monorchiids, resolves within the Monorchiinae Odhner, 1911, and is characterised by a relatively large ventral sucker, a sinistral genital pore immediately posterior to the ventral sucker, unfilamented eggs, a single testis, and vitelline follicles restricted to the level of the gonads. We assessed all previous records of monorchiids from lutjanid fishes and found only one to be convincing, that of Infundiburictus overstreeti (Gupta & Gupta, 1990) Wee, Cutmore, Pérez-del-Olmo & Cribb, 2020 from Lutjanus monostigma (Cuvier) in the Bay of Bengal. Another, Monorcheides xishaensis Shen, 1985, from Lutjanus argentimaculatus (Forsskål) in the Paracel Islands, South China Sea, is here recognised as a cryptogonimid, and is synonymised with Siphoderina asiatica Gu & Shen, 1979. In the remaining reports, the identity of the host is either ambiguous or doubtful, or the identity of the worm is not supported with sufficient evidence.

Dietary intake of polycyclic aromatic hydrocarbons (PAHs) from coral reef fish in the Persian Gulf — Human health risk assessment

The present study investigated accumulation of petrogenic polycyclic aromatic hydrocarbons (∑39PAHs) in the livers and muscles of three coral-reef fish (50 specimens) from the Persian Gulf, Kharg Island (Iran), specifically Lethrinus microdon (n = 18), Lutjanus argentimaculatus (n = 17), and Scomberomorus guttatus (n = 15). For all fish, PAHs originated mostly from petroleum and combustion sources. Concentrations of ∑39PAHs were 1004 ngg−1 freeze-dried weight (fdw) and 1390 ngg−1 fdw for liver and muscle, respectively. The biota-sediment accumulation factor of 20,181 and equivalent concentrations of ∑PAHs (liver) were highest for L. argentimaculatus. Most of the abundant PAHs identified were low molecular weight (LMW-PAH) (liver > muscle) with 2–3 aromatic ring. Results for the human health risk assessment concluded the probability of PAHs intake via fish consumption was considerable in this area (lifetime cancer risk (ILCR) > 1 × 10−5; hazard quotients (HQs) > 1; hazard index (HI) ≈6; the excess cancer risk (ECR) > 1 × 10−6) and, therefore, comprehensive management and long-term monitoring is needed.

Training fish for restocking: refuge and predator training in the hatchery has limited benefits for a marine fish.

Large numbers of hatchery-reared fish are released in stocking programmes; however, success is limited by high mortality. Predation is seen as the main cause of deaths but might be reduced by training fish before release to avoid predators and/or use refuge. In this study on a potential restocking species, yellowfin bream Acanthopagrus australis, the effects of predator training and refuge on the behaviour of fish in the hatchery were tested. In the first experiment, juvenile bream were exposed to predatory mangrove jack (Lutjanus argentimaculatus) fed exclusively on bream flesh while housed in tanks with and without refuge. Predator training altered fish behaviour when fish were re-exposed to predators, but the effects were subtle and varied between groups of fish. In contrast, refuge created strong and consistent changes in behaviour, significantly slowing down the amount of time that fish took to consume food. A second experiment focused on the effects of refuge. Bream were trained to use artificial seagrass or house bricks as refuge and then exposed to mangrove jacks in a laboratory predation experiment. When refuge was available, fish significantly slowed down their feeding rate. There was a small, transient increase in survival for fish given seagrass refuges, but this was irrespective of whether the bream were trained to use refuge. The results of this study indicate that the use of refuge may be innate and the benefits of refuge may be available to naive hatchery-reared fish or fish trained to use refuge shortly before release. This suggests that there is potential to improve post-release survival of fingerlings without time-consuming and expensive hatchery training.

Tracing the origin of fish without hatchery information: genetic management of stock enhancement for mangrove red snapper (Lutjanus argentimaculatus) in Taiwan

Stock enhancement is considered to be a valuable approach for restoring fishery resources. Because no specific official institution in Taiwan is responsible for the production of fry, the released fry are purchased directly from the private sector. However, fishermen from the private industry have not established a genetic background, so the genetic composition for each batch of released fry is unclear. Mangrove red snapper (Lutjanus argentimaculatus), a prominent species released in Taiwan, was collected after its official release. One hundred and two field samples were compared with four batches of hatchery fry (n = 685) by using a microsatellite-based multiplex PCR assay. Four of the field samples (3.9%; 4/102) were revealed to be from a fish farm and most likely from a single batch. This study revealed that wild mangrove red snappers are genetically different from those originating from farms, and their origins can be traced through molecular markers, even without information on breeding stocks.

Spatial and Seasonal Distribution of Recruitment and Population Connectivity of Lutjanus argentimaculatus among Marine Habitats in the World Biosphere Reserve of Cu Lao Cham-Hoi An

Results of our study show that juveniles of the mangrove red snapper are found all year round from the Cua Dai river mouth to Cam Kim upstream of the Thu Bon estuary, with no clear patterns of distribution between months. Variability in recruitment of juvenile fish of ≤50 mm TL was observed from June until February, and the youngest fish (≥18 mm TL) were found in mid-June. Adult mangrove red snapper TL ≥400 mm were only recorded from coral reef offshore islands. There is likely a connection between both fish habitats separated by a distance of approximately 18 km. The results of red snapper DNA analysis show homogeneity of juveniles and adult the population structures.

Indexing serum biochemical attributes of Lutjanus argentimaculatus (Forsskal, 1775) to instrument in health assessment

The present study was aimed to establish reference data for nine serum biochemical attributes (glucose, protein, albumin, globulin, albumin/globulin ratio, cholesterol, triglycerides, serum glutamate oxaloacetate transaminase [SGOT] and serum glutamate pyruvate transaminase [SGPT]) of a supreme aquaculture candidate, namely Lutjanus argentimaculatus. Further, the influence of ecotype (cage–wild), condition index and gender on biochemical attributes was evaluated. The results have shown that gender and condition index had no significant effect in the studied age group, whereas ecotype had a significant role, except on serum glucose levels, suggesting the prime importance of estimating ecotype-specific reference intervals for interpreting fish health. Intra-ecotype variability of serum biochemical attributes, namely serum protein, globulin, cholesterol and triglycerides, was less, suggesting the possibility of using these parameters as health indices within a specific ecotype. Consistency in terms of the least intra-ecotype variability coupled with PCA results points serum protein as the best ecotype-specific health index among the different parameters studied. Altogether, the results of the present study provide thought-provoking insights on serum biochemistry of L. argentimaculatus as a platform for the health management of this supreme aquaculture candidate.

Effects of di-n-butyl phthalate on gills- and liver-specific EROD activities and CYP1A levels in juvenile red snapper (Lutjanus argentimaculatus)

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.

First record of an anchor worm Lernaea cyprinacea on a tropical abortively migrating fish, Lutjanus argentimaculatus, in eastern Japan

First record of an anchor worm Lernaea cyprinacea on a tropical abortively migrating fish, Lutjanus argentimaculatus, in eastern Japan

Population structure undetectable using genetic markers in Mangrove Jack Lutjanus argentimaculatus from its cool-water range limit in eastern Australia

Failure to consider genetic structure in fish populations when collecting aquaculture broodstock can negatively affect fitness, and hence conservation and management goals. Here we used mitochondrial DNA from the 5’ end of the control region (D-loop) and four microsatellite markers to evaluate population genetic structure in the Mangrove Jack Lutjanus argentimaculatus with a view to guiding broodstock collection at the southern extremity of its east Australian range. There was no evidence of genetic structure within the entire tropical, subtropical and temperate east Australian distribution of L. argentimaculatus. Although this species may exhibit clinal morphological and life-history variation at its southern range limit, we did not detect wide- or fine-scale spatial genetic structure to indicate the presence of non-random evolutionary processes. Broodstock collection of L. argentimaculatus need not be geographically restricted in eastern Australia, but fisheries management should consider variation in life history and recruitment success at the species’ edge.

Distribution of Mangrove Red Snapper Lutjanus argentimaculatus in response to hydrodynamic condition at the reef patches of Lankayan, Sugud Islands Marine Conservation Area, Sabah, Malaysia

The species Lutjanus argentimaculatus is a prized food-fish in the tropical and subtropical fisheries, as well as the aquaculture industry. This study investigated the distribution of L. argentimaculatus at three patch reefs of Lankayan Island, within the Sugud Islands Marine Conservation Area. Fish surveys of this species were conducted 12 times at each of the selected patch reefs, from August 2016 until March 2017. In addition to taking underwater video footages, hydrodynamic parameters, i.e. water current direction and current speed were recorded during each survey. The distribution patterns of the fish were then plotted against these parameters to determine any correlation, in response to these parameters. As a result, we found a significant relationship between the current direction and the position of L. argentimaculatus at the reef where the schoolings were found to occur. We found that regardless of the current speed, the schools of L. argentimaculatus were always present at the reef slope facing the incoming current. This finding is important for the management and conservation of this species, which is a targeted species in the Live Reef Fish Food Trade (LRFFT), and is useful for the manager of a Marine Protected Area (MPA) in general. This finding is also important as it provides useful insights into the ecology of Lutjanus spp.

The occurrence of the Lessepsian migrant Lutjanus argentimaculatus in the Mediterranean, (Actinopterygii: Perciformes: Lutjanidae) first record from the coast of Israel

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.

The first record of a mangrove red snapper, Lutjanus argentimaculatus (Actinopterygii: Perciformes: Lutjanidae) from the Aegean Sea (Gulf of Izmir, Turkey)

A specimen of Lutjanus argentimaculatus (Forsskål, 1775) was caught on 4 October 2018 by a commercial gillnet fishery from shallow waters of the Gulf of Izmir, northern Aegean Sea, at a depth of 8 m. The presently reported study constitutes the first record of the mangrove red snapper for the Aegean Sea but also the third record for the Mediterranean Sea.

Growth Pattern The Second Generation of Marine Fish Larvae Mangrove Red Snapper Lutjanus argentimaculatus (Forsskål, 1775)

Mangrove red snapper Lutjanus argentimaculatus is a high economically value of snapper. Growth is important biological parameters during larvae stage. The growth of the second generation (F-2) of cultivated L. argentimaculatus is important to be evaluated as part of cultivation success. This study was conducted to determine the growth pattern of L. argentimaculatus F-2 during larval to juveniles stage. Larval rearing was done in hatchery. Larvae were fed zooplankton rotifers Brachionus rotundiformis and Artemia, also micro pelet as the artificial feed. Microscopic measurement on larval samples were performed periodically every 5 days from 5 to 40 days old larvae, by using 10 larval samples each time. The biological parameters of larvae were total length, standard length, dorsal spine length, ventral spine length, anal spine length and body weight. The results of this study indicated that the growth of mangrove red snapper larvae took place for 35-40 days to metamorphosis become juveniles. The growth pattern on all parameters was exponential. The larval total length has a positive correlation to its body weight with correlation value of 0.99. Larvae had certain characteric growth during metamorphosis stage. Mangrove red snapper L. argentimaculatus F-2 had a similar growth pattern with those of larvae F-1.

Effect of Pectin on the Characteristics of Edible Film from Skin Gelatin of Red Snapper (Lutjanus argentimaculatus)

The aim of this research was to determine the effect of addition of pectin on characteristics of edible film from gelatin of red snapper (Lutjanus argentimacalatus) skin. Concentration of pectin used were 0%, 0.2%, 0.4%, 0.6%, 0.8% and 1%. Water content, thickness, tensile strength, elongation, and the transmition rate of the water vapor of edible film were analysed. Results from analysis of variance showed that different concentration of pectin significantly affected (P<0.05) on the water content, thickness, tensile strength, elongation, and transmition rate of water vapor of edible film. Therefore, it was suggested that addition of 0.6% of pectin showed a good quality of edible film and in accordance with the Japan International Standard (JIS).

An assessment of fish and marine growth associated with an oil and gas platform jacket using an augmented remotely operated vehicle

Scientists, industry and regulators are seeking to understand the influence of oil and gas infrastructure in our oceans to mitigate its impacts and maximise environmental benefits. This project equipped a standard work-class ROV with a light-weight stereo-video camera system to collect high definition imagery of fish and habitats formed by marine growth associated with Woodside Energy's Goodwyn Alpha Platform jacket (GWA) 138 km offshore of Dampier, north-west Australia. ROV video surveys were rapidly performed by industry on four faces of the GWA jacket, from the surface to the seabed at 130 m, yielding 1 h and 14 min of imagery. The stereo-video cameras continued to film during standard ROV operations collecting a further 150 h of HD imagery, used to build a comprehensive fish species list. A total of 8676 individual fish from at least 57 species and 20 families, with an estimated combined mass of 8719 kg, were recorded from the vertical transects of four faces of the jacket. An additional 43 fish species from 21 families were recorded via rapid assessment of a subset of the additional, standard ROV operations imagery. The jacket was characterised by abundant Caranx sexfasciatus (bigeye trevally), Pseudanthias spp. (basslets), Heniochus diphreutes (schooling bannerfish), Labridae sp. (wrasse) and Acanthurus spp. (surgeonfish). Several fish important to the demersal scalefish fishery in the region were observed, including: Lutjanus argentimaculatus (mangrove jack), Lutjanus erythropterus (crimson snapper), Lutjanus malabaricus (saddletail snapper), Lutjanus russellii (Moses' snapper). Eleven broad marine growth types were observed with encrusting/enveloping species (brown algae, filamentous mat, coralline algae, calcite) and hard corals (Tubastrea sp.) present in the greatest coverage. Both marine growth and fish assemblages changed markedly with depth. The addition of a lightweight stereo-video system to an industrial ROV and the allocation of short amounts of time for rapid vertical surveys provided important information on the ecology of an oil and gas platform jacket. Future industrial ROV campaigns should consider utilising this approach to gather scientific information that may have value in the context of decommissioning comparative assessments and, more generally, improves our understanding of the impact of oil and gas infrastructure in our oceans.