Frigate Tuna Research Articles

Estimation of Frigate Tuna (Auxis thazard) resource potential from Sibolga Waters

Frigate Tuna (Auxis thazard) is one of commercial production of large pelagic fish fisheries in Sibolga Waters. The high demand for this fish has led to large-scale fishing practices that can disrupt the balance of fish populations in nature. Therefore, the objectives of the present study were to determine the maximum sustainable potential (Maximum Sustainable Yield), optimum effort (fopt), and to find out the level of utilization, effort and catch of Frigate Tuna allowed. The secondary data analysis was using the Fox model. The results showed that the sustainable potential (MSY) of Frigate Tuna resources from Sibolga Waters amounted to 7,664.108239 kg/year with fopt value was 2, 539.025526 trips/year. utilization rate over the past 5 years has an average value of 153.2106% and an effort rate of 123.01%. It is concluded that the utilization resource level of Frigate Tuna from Sibolga Waters has been overfishing.

SUPERIOR FISHING COMMODITIES IN SOUTHCOAST OF EAST JAVA, INDONESIA

Indonesia is the largest archipelagic country in the world and has various marine resources. Fishery development is one of the priorities of East Java Province Government and the selection of the superior fishing commodities becomes important to fishery growth. The objective of this research is to select the superior fishing commodities in south coast of East Java Province, including eight Districts: Pacitan, Trenggalek, Tulungagung, Blitar, Malang, Lumajang, Jember, and Banyuwangi. Both Location Quotient models in quantity and value are developed and the fishing data during 2013-2017 are adopted in the study. As the results, the superior fishing commodities by quantity, by value, and by both quantity and value are selected for whole south coast of East Java Province and eight districts respectively. The result show that the most fishing commodities quantities of production are Scads, Fringe scale sardinella, Short bodied mackerel, Indian oil sardinella, Skipjack tuna, Anchovies, Big eyes, Kawa kawa, Frigate tuna, and Hairtail. The biggest production is scad. The most valuable fishing commodity in south coast of East Java Province is hairtail with 154,324.8 million rupiah, while Tuna and Skipjack generate value amount 484,652.43 million Rupiah each year. Finally, policy implication and strategies are proposed for the superior fishing commodities in south coast of East Java Province.

Catch marketing analysis of Frigate tuna (Auxis thazard): caught by lift-net at Bone District, South Sulawesi Province-Indonesia

Lift-net (local term: Bagan Rambo) is one of the most productive fishing gear in the coastal community of Gulf of Bone, including those in the Bone District. This study aims to explain the characteristics of the marketing channels of frigate tuna caught by fishermen and the effectiveness and efficiency of frigate tuna market system. The study was conducted from December 2017 to February 2018 at Bone District, South Sulawesi Province-Indonesia with a purposive sampling method of 37 units of lift-net and 481 fisheries households. The results of the study show that lift-net owners and fishmongers are the main channels of catch marketing (66.7%). For Bone sub-district of Tanete Riattang Timur 50% of catches go fishing auction and fisheries companies. The effective marketing system of frigates tuna are: 1) fishermen get more profit if they sell their catch in kg instead of selling per bucket, 2) the boat owner and fishmonger get a big profit, at the sale of a minimum price. The effective marketing channel is directly selling catches to fisheries companies.

Accumulation of halogenated polycyclic aromatic hydrocarbons by different tuna species, determined by high-resolution gas chromatography Orbitrap mass spectrometry

Halogenated polycyclic aromatic hydrocarbon (HPAH) concentrations in tissues from three tuna species Thunnus albacares (yellowfin tuna), Katsuwonus pelamis (skipjack tuna), and Auxis thazard (frigate tuna) were determined by high-resolution gas chromatography Orbitrap mass spectrometry. The tuna samples were collected from the Indian Ocean. The instrument conditions gave high mass accuracy at 0.9 m/z isolation width of the mass filter and a mass error of <±1.0 ppm for many HPAHs. A total of 29 of the 30 targets chlorinated PAHs (ClPAHs) and 20 of the 21 targets brominated PAHs (BrPAHs) were detected in the tuna muscle samples. The mean total ClPAH, BrPAH and PAH concentrations for tuna were 127.2, 156.6 and 682.8 ng/g lipid weight, respectively. The mean total ClPAH and BrPAH concentrations (ng/g lipid weight) in the tuna were considerably lower than that of PAH concentrations. The mean total ClPAH, BrPAH and PAH concentrations in T. albacares respectively were 185.8, 249.2 and 784.1 ng/g lipid weight, irrespective of the body sizes. The mean total ClPAH, BrPAH and PAH concentrations in K. pelamis respectively were 45.1, 24.8 and 555.6 ng/g lipid weight. The mean total ClPAH, BrPAH and PAH concentrations in A. thazard respectively were 34.09, 4.73 and 433.24 ng/g lipid weight. The total ClPAH concentrations and body weights significantly positively correlated for T. albacares. The mean total ClPAH concentration in white muscles was significantly higher (p < 0.05) for large than for small T. albacares. This suggests ClPAHs could bioaccumulate in T. albacares, possibly because they are poorly metabolized. The chlorinated phenanthrene and pyrene concentrations indicated tuna accumulate these compounds increasingly effectively as the tuna grow. This was the first time large numbers of HPAHs were found in biological samples. HPAHs may adversely affect the health of humans consuming tuna.

Some biological aspects and molecular variations in frigate tuna, Auxis thazard of the coastal waters around Sri Lanka

Auxis thazard (frigate tuna), is a commercially important fish species in Sri Lanka. Although Sri Lanka is fortunate to have a large resource of tuna, little information is available on the biology, genetics and stock structure of A. thazard. Hence, the present study was conducted to study the biology, genetics and stock structure of A. thazard in coastal waters around Sri Lanka. The fish samples were collected from October 2015 to September 2017 from day-boats operating in the Western, North Western, Eastern and Southern Provinces of Sri Lanka. For this period, the length-weight relationship and Fulton’s condition factor (K) calculated for A. thazard using standard length measured in centimetres and weight measured in grams were shown as W = 0.1091L 3.3385 and 1.93, respectively, indicating a relatively healthy growth pattern and a comparatively unpolluted habitat. Studies on the stomach contents revealed that A. thazard are non-selective carnivors, feeding on diverse animal prey items such as small fish species, shrimps and cephalopods available in the surrounding waters. The fecundity of female A. thazard was shown to be 48,056 to 267,000 eggs. The calculated GSI values showed that the peak spawning period for male A. thazard extends from May to August and for the females from May to July. The phylogenetic analysis of the mitochondrial D-loop region sequences of 75 selected samples representing all the geographical regions studied showed that the fish of different regions are clustering together. Hence, for fisheries management strategies, A. thazard found in the coastal waters of the Western, North Western, Eastern and Southern Provinces of Sri Lanka could be considered as a single stock.

CHARACTERISTIC OF SMALL SCALE TUNA FISHERIES ASSOCIATED WITH FADs IN LABUHAN LOMBOK, WEST NUSA TENGGARA-INDONESIA

Fish aggregating devices, or FADs are used extensively in developing countries to attract and to collect pelagic fish and give positive impacts on fish production. Use of FADs has started in early 20th century with different names among the countries and regions. This study investigated the design, deployment, distribution, density and the number of FADs used by small scale tuna fisherman in Labuhan Lombok, including characteristics of fishing boat, fishing gear, catch composition, catch per unit of effort (CPUE), fish diversity and species richness. There were 65 FADs identified in this study and 47 of them were in normal distribution. Type of the FADs used was anchored FADs, spreading between 56.63 to 267.70 NM from Labuhan Lombok fishing port. The placement of FADs were arranged in such a way as to resemble a fence, in which the distance from one to another was close. It is expected to disrupt tuna movement towards the strait in the small islands around West Nusa Tenggara. The dimensional size of vessels used to catch fish was small boat (&lt; 7 GT) with handline as fishing gears. Fish catches were dominated by skipjack (40.30%) followed by yellowfin tuna (30.90%), tuna juvenile (13.44%), frigate tuna (4.19%), albacore (3.41%), bigeye tuna (2.71%) and others (5.03%). The highest nominal CPUE occurred in January and February, accounted for 278 kg and 285 kg per day at sea respectively. The average diversity of fish and species richness in FADs area were 1.07674 and 1.3573 correspondingly. Overall results inform that diversity of fish, productivity and ecosystem were at sufficient condition and mid ecological pressure but species richness was in low condition. If this continues, it is possible that tuna diversity will decrease and endanger the survival of tuna species and others species related to the tuna.

Genetic analysis reveals the presence of frigate tuna (Auxis thazard) in the bullet tuna (Auxis rochei) fishery of the Iberian Peninsula and the western-central Mediterranean Sea

One the problems with fisheries assessment and management is the presence of multiple species in a single fishery. In such cases, each species may respond differently to management measures. In this study, we report for the first time the presence of a second species, the frigate tuna, Auxis thazard (Lacepede, 1800), in the fishery for bullet tuna, Auxis rochei (Risso, 1810), off the Iberian Peninsula and the western-central Mediterranean Sea. The bullet tuna is heavily targeted by both artisanal and commercial fisheries; thus, the presence of a second species may complicate management. Seven frigate tuna individuals (1.6%; 95% CI 0.7%–3.4%) were detected after analyzing more than 400 individuals, and they were unambiguously assigned to the species bullet tuna after the analysis of two unlinked genetic loci (nuclear gene Tmo-4c4 and the mitochondrial DNA control region). The unexpected presence of a species distributed in temperate and tropical waters, such as the frigate tuna in this northern location, may be a consequence of global warming. However, continuous monitoring with a validated methodology for species identification is needed to confirm this hypothesis.

The complete mitochondrial genome of frigate tuna (Auxis thazard) from South China Sea

Auxis thazard is one of genus Auxis and widely distributed in tropical and subtropical waters. In this study, we described the complete mitochondrial genome of Auxis thazard. The genome is 16,506 bp in length, encoding the standard set of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a non-coding D-loop, with a circular organization. The overall base composition of the whole mitochondrial genome was A (27.86%), T (24.88%), G (17.16%), and C (30.10%) with an AT bias of 52.94%. The longest protein-coding genes of these species was ND5, whereas the shortest ATP8.

GENETIC STUDIES REVEAL THE PRESENCE OF UNEXPECTED SPECIES IN COMMERCIAL FISHERIES

GENETIC STUDIES REVEAL THE PRESENCE OF UNEXPECTED SPECIES IN COMMERCIAL FISHERIES

Combined impacts of oregano extract and vacuum packaging on the quality changes of frigate tuna muscles stored at 3±1°C.

Aim:The combined effects of oregano extract with vacuum packing (VP) on the quality enhancement of dark and white muscles of frigate tuna (Auxis thazard) stored as intact fillet at refrigerated (3±1°C) conditions were studied.Materials and Methods:About 35 kg of fish were filleted without skin removal and randomly divided into two groups. One group without treatment (control) and the remaining group were dipped in a sterilized oregano extract solution for 5 min. Chemical, microbiological, sensorial, and textural analyses were carried out in each of dark and white muscles of frigate tuna fillets during storage.Results:Several quality indexes were higher in dark muscle than white muscle. The sensory assessment indicated that both muscles from control had a shelf life of 12 days. Quality parameters of both muscles had the same tendency and were significantly affected by time and also by the presence of plant extract in VP. Although VP alone was sufficient to delay lipid oxidation on fish fillets, especially on dark muscle but cannot enhance the textural deterioration in both muscles.Conclusion:Consequently, the employment of such combination had a cumulative effect on preservation, resulting in prolonging the shelf life of both frigate tuna muscles.

Remarkable morphological variation in the proboscis of Neorhadinorhynchus nudus (Harada, 1938) (Acanthocephala: Echinorhynchida).

The acanthocephalans are characterized by a retractible proboscis, armed with rows of recurved hooks, which serves as the primary organ for attachment of the adult worm to the intestinal wall of the vertebrate definitive host. Whilst there is a considerable variation in the size, shape and armature of the proboscis across the phylum, intraspecific variation is generally regarded to be minimal. Consequently, subtle differences in proboscis morphology are often used to delimit congeneric species. In this study, striking variability in proboscis morphology was observed among individuals of Neorhadinorhynchus nudus (Harada, 1938) collected from the frigate tuna Auxis thazard Lacépède (Perciformes: Scombridae) in the South China Sea. Based on the length of the proboscis, and number of hooks per longitudinal row, these specimens of N. nudus were readily grouped into three distinct morphotypes, which might be considered separate taxa under the morphospecies concept. However, analysis of nuclear and mitochondrial DNA sequences revealed a level of nucleotide divergence typical of an intraspecific comparison. Moreover, the three morphotypes do not represent three separate genetic lineages. The surprising, and previously undocumented level of intraspecific variation in proboscis morphology found in the present study, underscores the need to use molecular markers for delimiting acanthocephalan species.

Hair mercury levels and dietary exposure of mercury in relation to fish consumption among coastal population in Negombo, Sri Lanka

Consumption of contaminated fish is the major source of the human exposure to total mercury (T-Hg) and methyl mercury. This study reports the fish consumption habits of three groups based on the age category and their occupation; “Children” (age 9-20 years) and two groups of “Adults” (age above 21 years) based on their occupation; “Adults-Fishermen” (fishermen) and “Adults-Other”. Hair T-Hg levels were measured from 30 individuals (age 9-48 years) from Negombo area in Sri Lanka. All individuals in this survey consumed fish at least six servings per week, which belongs to the high fish consumer category (&gt; 3 servings/week) according to World Health Organization (WHO) guidelines. The main fish groups consumed by the respondents were mainly yellow-fin tuna (YFT), skipjack tuna (SKT), kawakawa and frigate tuna and small fish such as sardines (spotted sardines, goldstripe sardine, other sardines, scads and trevallies). The majority consumed an equal amount of big fish and small fish. The average weekly fish consumption per individual varied depending on the test group (Children; 1270 g/week per person, Adults-other; 1078 g/week per person and Adults-fishermen 1852 g/week per person) which exceeded United States Food &amp; Drug Administration (USFDA) recommended level of 340 g/ week of seafood containing low concentration of Hg. The mean hair T-Hg of respondents of Negombo population was 4.89±3.23 µg/g (range 1.60-13.38 µg/g), which exceeded the United States Environmental Protection Agency (USEPA) reference dose (1 µg/g) for T-Hg level of hair. The total hair mercury in three respondent groups (Children 3.33±1.36 µg/g, Adults-other 2.89±1.26 µg/g and Adults-Fishermen 6.08±3.62 µg/g), were not significantly different (p&gt;0.05) from each other. Real exposure value of three respondent groups were not significantly different (p&gt;0.05). There was a low strength positive correlation (r=0.353, p&gt;0.05) between hair T-Hg levels with the weekly large fish consumption.

Descriptions of Neorhadinorhynchus nudum (Cavisomidae) and Heterosentis paraholospinus N. SP. (Arhythmacanthidae) (Acanthocephala) From Fish Along the Pacific Coast of Vietnam, With Notes On Biogeography.

Two species of acanthocephalans are described from fishes caught along the Pacific coast off eastern Vietnam in 2016: (1) Neorhadinorhynchus nudum ( Harada, 1938 ) Yamaguti, 1939 (Cavisomidae) from the frigate tuna Auxis thazard (Lacépède) (Scombridae) in Nha Trang, Pacific south Vietnam, and (2) Heterosentis paraholospinus n. sp. (Arhythmacanthidae) from 3 species of fish: the common ponyfish Leiognathus equulus (Forsskål) (Leiognathidae) and the torpedo scad Megalaspis cordyla (Linn.) (Carangidae) off Nha Trang and Binh Thuân, respectively, and the yellowspotted ponyfish Nuchequula flavaxilla Kimura, Kimura, and Ikejima (Leiognathidae) at Quang Ninh in Pacific waters of Vietnam. Females of N. nudum are fully described for the first time in the Pacific Ocean. Heterosentis paraholospinus n. sp. is similar to Heterosentis holospinus Amin, Heckmann, and Ha, 2011, in having an unspined anterior trunk cone, nucleated pouch at the posterior end of the receptacle, and spines covering the entire trunk, but it differs in having a long cylindrical trunk, lemnisci much longer than the receptacle, more and different-sized proboscis hooks, and subterminal female gonopore. Biogeographical notes are discussed for both genera.

Study of fresh Frigate Tuna (Auxis thazard) quality sold by mobile fish retailer in Makassar

Frigate tuna (Auxis thazard) is widely marketed and consumed in Makassar. Most of the fresh fish for household needs are purchased from traditional mobile fish retailer (Pa’gandeng) in Makassar. However, data on the quality of fresh frigate tuna reaching the consumer of household level is still lacking. This research was conducted in three areas, namely east, south, and north of Makassar City, South Sulawesi. This study was aimed to describe the quality characteristics of fresh frigate tuna retailed by Pa’gandeng. The study was conducted by randomly taking four samples of fish from Pa’gandeng at three points of sale (sale time) in each part of the city. Physical and organoleptic parameters were measured directly at the sampling locations, while the chemical and microbiological parameters were analyzed in the laboratory. Effect of time on the fish freshness parameters were tested using ANOVA with a confidential level of 95% (α = 0.05). When ANOVA indicated the presence of a significant effect, LSD (Least Significant Difference) test was applied to determine which points of observation that the corresponding parameter exhibited a significant difference. The relationship between the observed parameters was analysed using regression analysis. Results of organoleptic, microbiological, and chemical analysis showed that the fresh frigate tuna retailed by Pa’gandeng in Makassar was in good quality and, therefore, suitable for consumption. The ANOVA test indicated that the parameters that significantly different between the sale points were the temperature and organoleptic values.

Morphological and molecular study of Neorhadinorhynchus nudus (Harada, 1938) (Acanthocephala: Cavisomidae) from Auxis thazard Lacepede (Perciformes: Scombridae) in the South China Sea.

In the present study, Neorhadinorhynchus nudus (Harada, 1938) is reported from the frigate tuna Auxis thazard (Lacepéde) (Perciformes: Scombridae), in the South China Sea for the first time. The detailed morphology of N. nudus was studied using light and scanning electron microscopy based on the newly collected material. The results showed some morphometric variability between our specimens and previous studies, including the number of hooks per longitudinal row and the size of copulatory bursa and eggs. Our SEM observations also revealed all proboscis hooks emerged from elevated round rims on proboscis surface. In addition, N. nudus was firstly characterised using molecular methods by sequencing and analysing the ribosomal ITS and mitochondrial cox1 regions. There is no nucleotide divergence found in the ITS sequences, but a low level of nucleotide variability detected in the cox1 regions (the level of intraspecific nucleotide variability being 0.75% to 2.54%). The DNA sequence data obtained herein will indeed be a useful reference for rapid and accurate species identification of Neorhadinorhynchus.

Studies on Population Characteristics of Frigate tuna, Auxis thazard (Lacepede,1800) Occurring in the North West Coast of India

Studies on Population Characteristics of Frigate tuna, Auxis thazard (Lacepede,1800) Occurring in the North West Coast of India

Feeding ecology and consumption rate of broadbill swordfish (Xiphias gladius) in Ecuadorian waters

The feeding ecology and consumption rate of the broadbill swordfish (SWO, Xiphias gladius) from Ecuadorian waters were assessed by stomach content analysis of 256 individuals ranging between 91 and 291 cm in straight fork length (FL). Based on the alimentary index (%AI), the jumbo squid (Dosidicus gigas) was the most important prey species (58.93%AI), followed by bullet and frigate tunas (Auxis spp.) (17.94%AI). Permutational multivariate analysis of variance (PERMANOVA) detected one size-related shift in feeding habits to occur at FL ~ 190 cm, whereas no spatial variations in diet composition were observed. Similarity percentages (SIMPER) analysis revealed that the diet of small SWO (≤ 140 cm FL) and medium SWO (140–190 cm FL) was mainly characterized by Dosidicus gigas (contributing to 50.77 and 66.82% of the similarities, respectively) and Auxis spp. (18.14 and 17.23%, respectively); Auxis spp. and Thysanoteuthis rhombus, however, were the greatest contributors to the similarity in large SWO (≥ 190 cm FL) (47.87 and 22.06%, respectively). The daily meal was estimated to be 468.03–676.78 g day−1, which corresponded to a daily ration of 1.63–8.24% body mass (BM, in g) day−1. The results of this study indicate that the SWO is a mesopelagic predator that plays an important role in structuring the pelagic ecosystem of the Ecuadorian Pacific Ocean.

Feeding habits of juvenile yellowfin tuna (Thunnus albacares) in Ecuadorian waters assessed from stomach content and stable isotope analysis

Size-related shifts in feeding habits of juvenile yellowfin tuna (YFT), Thunnus albacares (Bonnaterre, 1788), in Ecuadorian waters were assessed using stomach content analysis (SCA) (n=339) and stable isotope analysis (n=83). In all size classes, fishes were the predominant prey group in the diet (Alimentary Index, %AI=96.86) followed by cephalopods (%AI=3.29) and crustaceans (%AI=0.03). PERMANOVA analysis revealed significant variations in diet with body size: i) Class I YFT (≤50cm in fork length, FL) fed mainly on laternfishes, family Myctophidae (%AI=37.34), and jumbo squid, Dosidicus gigas (%AI=36.06), Class II YFT (50–60cm, FL) consumed bullet and frigate tunas, Auxis spp., unidentifiable fish and jumbo squid (%AI=47.75, %AI=25.06 and%AI=21.67, respectively), and Class III YFT (≥60cm, FL) preyed almost exclusively on bullet and frigate tunas (%AI=90.85). Mean±SD muscle isotope values were 12.14±1.95‰ for δ15N and −17.42±0.27 for δ13C‰; mean (±SD) liver values were 11.30‰ for δ15N and −17.42±0.27‰ for δ13C. Overall, liver and muscle samples showed significant size-related differences in δ15N and δ13C. Stable isotope Bayesian ellipses, SEAc, did not show trophic overlap among size classes. A significant positive linear correlation was observed between δ15N and δ13C measured in liver and muscle tissues with body size, suggesting an increase of prey size as tuna grew. These results indicate that the observed size-related diet shifts are not only related to prey type, but also to prey size.

Value Chain Analysis for Frigate Tuna (Auxis thazard) in Selected Aquatic and Agricultural Systems Communities along the Sogod Bay Area, Southern Leyte, Philippines

The frigate tuna industry in the Sogod Bay area of Southern Leyte is constrained by various factors. The study aimed to look for effective pathways and linkages for upgrading the industry, transforming it to a highly competitive and profitable system for the poor and marginalized people of the Sogod Bay area. Examination of the value-creating flow of the industry from the input supply sector, production, trading until the finished goods are delivered to the end consumers was done. Participatory systems analysis was used to examine the profitability of an existing value chain, identify problems and areas for improvement for frigate tuna enterprise in Limasawa Island and selected communities in Sogod, Southern Leyte, Philippines. Value chain mapping showed fresh frigate tuna traded to local buyers, trader-assemblers and brokers in Pasil Fish Port, Cebu City. Downstream, retailers traded products directly to institutional buyers. Data revealed that at the current market situation, there is 48.83% excess demand of frigate tuna. Chain performance analysis also showed that traders in Limasawa generated higher net returns than the upstream players in Sogod, Southern Leyte. Moreover, upstream players across study sites are alarmingly facing declining catch per unit effort in their fishing activity. Logistic issues and external influences were evident in the area. The presence of large fishing vessels in a “no fishing” area aggravated the decline in the catch per unit effort of frigate tuna in the Sogod Bay area. Strategies to upgrade the chain are forwarded to bring back the frigate tuna enterprise, thus, generating more benefits and opportunities for high value adding products where the poor and marginalized sectors in the selected AAS communities can participate.

Phylogenetic and morphometric relationships between two species of genus Auxis from the South China Sea and Java Sea

This study was aimed at examining the phylogenetic and morphometric relationship of frigate tuna (Auxis thazard) and bullet tuna (Auxis rochei) using mtDNA D-loop (control) region sequences and truss measurements, respectively. Maximum-likelihood (ML) tree and median-joining network showed that haplotypes from Auxis populations grouped separately. Discriminant function analyses and non-metric multidimensional scaling of morphometric data showed that bullet and frigate tuna were differed mainly with respect to truss measurements on the anterior region, suggesting adaptation to different diets available in different environments. Historic demographic analyses of sequence data showed that both bullet and frigate tuna had not undergone a significant sudden population expansion recently. Non-significant value of Tajimas’s D and Fu’s FS were indicated an effective large and stable population size for longer period of both species in South China Sea and Java Sea species. This study gives first report on the complementary relationship between morphometric and genetic analysis in stock discrimination of genus Auxis.