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Kutaraja Ocean Fishery Port is the oldest port in Banda Aceh City, Lampulo. Fishery resources are a new potential in the regional economic development of Aceh province. Fish resources that have great potential are from the large pelagic fish groups, including Tuna, Small Tuna and Skipjack (TTS) . Fishery characteristics are used to carry out sustainable fishing. This research was conducted at PPS Kuta Raja, Aceh for one year. Data collection was carried out directly through site surveys and interviews with related fisheries actors. Biological data and capturing aspects were carried out using a stratifield random sampling system by placing enumerators. The results showed that the production of TCT at PPS Kutaraja was dominated by 2 fishing gears, purse seine and hand lines. Based on the results of enumeration in 2020, the estimated total production of tuna skipjack and small tuna at PPS Kuta Raja reaches 11,520 tons. The highest total estimated fish catch is skipjack tuna (Katsuwonus pelamis) (SKJ) 5,802 tons, Bullet tuna (Auxis rochei)(BLT) 2814 tons, Yellow fin (Thunnus albacares) (YFT) 2,452 tons, Krai Tongkol (Auxis thazard) (FRI) 448 tons, and Eastern little tuna (Euthynnus affinis) (KAW) 1,745 tonnes. All of the fish caught were dominated by immature fish. So it is very necessary to evaluate the use of fishing gear or the licensing of FADs. The monthly CPUE distribution pattern is the same, where in August it reaches the highest CPUE and in October it reaches the lowest CPUE value.

Nusa Penida adalah kawasan konservasi perairan (KKp) yang memiliki keragaman jenis ikan yang tinggi. Penangkapan ikan target oleh nelayan perlu diatur dan dikelola dengan baik untuk menghindari tangkap lebih. Tujuan penelitian adalah menilai pengelolaan perikanan ikan tongkol lisong (Auxis rochei) yang sudah diterapkan di Nusa Penida menggunakan indikator Ecosystem Approach for Fisheries Management (EAFM). Penelitian dilakukan di perairan Nusa Penida, Provinsi Bali, pada Juli-Desember 2018. Pengumpulan data meliputi data ekologi (panjang dan bobot ikan, serta kualitas air) melalui survei terhadap hasil tangkapan dan perairan; data sosial-kelembagaan melalui kuesioner kepada 54 responden nelayan (jaring hanyut, jaring insang, pancing) dan wawancara dengan para pemangku kepentingan. Analisis data dilakukan secara deskriptif sesuai dengan domain dan indikator pada EAFM. Hasil penelitian menunjukkan bahwa ikan tongkol lisong mempunyai panjang rata-rata 24,59 cm dengan kisaran panjang (21-34) cm, lebih kecil daripada yang tercatat pada FishBase yaitu 35-50 cm. Nilai spawning potential ratio adalah 23% yang mengindikasikan overfished. Kualitas air sesuai dengan baku mutu perairan untuk biota laut. Penerapan kearifan tradisional yaitu Nyepi Segara ditaati oleh masyarakat lokal sebagai upaya untuk menjaga kelestarian sumber daya ikan (SDI). Penilaian pengelolaan perikanan tongkol lisong menggunakan indikator EAFM menyimpulkan bahwa pada domain SDI terjadi indikasi overfished. Domain habitat (kualitas air dan tutupan karang) dalam kondisi baik. Domain sosial dan ekonomi dalam kondisi baik, kecuali pendapatan responden (54%) kurang dari Rp1.500.000,00.

Target strength (TS) is one of the main parameters for determining fish density, abundance and biomass in acoustic technique. Therefore, it is of utmost importance to obtain an accurate TS estimate and to minimize bias from its measurement. Various factors contribute to bias in acoustic TS, namely the high diversity of species, body shape, size and also frequencies used. In this paper we compare and examine the acoustic narrowband (NB) and wideband (WB) approaches to better understand the TS response to various frequencies. The use of acoustic wideband approach, is expected to perform better and be less-biased than the narrowband, which is still widely used. The measurement of bullet tuna (Auxis rochei) and bonito (Euthynnus affinis) for the same fork length (FL) size showed the power of four frequency dependent (f^4). Furthermore, a comparison between NB frequency of 200 kHz versus WB at the nearby frequencies of 190-200 kHz and 200-210 kHz showed a significant Pearson correlation value for bonito fish size range from 17-26.6 cm, whereas in the case of bullet tuna, fish had no significant correlation at alpha=0.05 for fish size range from 16.4-26 cm.

Larvae of Auxis rochei and Auxis thazard are commonly found in tropical to temperate waters around the world; however, their identification is difficult due to their similar morphological characteristics. In order to determine the morphological differences between larvae of these two species, we identified larvae of 192 A. rochei and 119 A. thazard using species-specific genetic markers and compared their melanophore patterns at each growth stage. The larvae of both species ranged from 3.5 to 6.9 mm in length and were identified with high accuracy based on the patterns of melanophore distribution at the snout tip and on the caudal peduncle. Using these morphological characteristics, we developed an identification key for the larvae of these two Auxis species based on their growth stage.

The objectives of the present study were to determine the size distribution, growth pattern, feeding habit and stomach fullness index of bullet tuna Auxis rochei in the Makassar Strait, West Sulawesi. The research was conducted for six months between March and August 2017. Sampling collection was carried out using the handline technique. A total of 2160 fish were caught. Their total length ranged from 15.8 to 28.5 cm and weight ranged from 52.3 to 366.5 g. The total length of male fish ranged from 18.5 to 28.5 cm and weight ranged from 77.5 to 366.5 g. The total length of female fish ranged from 15.8 to 27.5 cm and weight ranged from 52.3 to 328.8 g. The growth pattern of bullet tuna for both male and female fish was classified into a positive allometry (b>3); the type of food found in the fish gut consisted of crustacean (12.50% to 25.64%), chepalopods (7.32 to 34.80%) and unidentified (47.69 to 64.51%), respectively. Nonetheless, the predominant food condition was not identified and in the gut there was generally no food present. The stomach fullness index ranged from 1.13% to 7.18%, ¾ (12.11 to 15.74%), ½ (12.27 to 23.14%) and empty (59.26 to 65.74%). The length size distribution of male bullet tuna was larger than the female with a positive allometric growth pattern. However, the growth pattern of male and female bullet tuna statistically showed no difference.

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.

Thunnus thynnus (Atlantic bluefin tuna, ABT) and other tuna species reproduce in the Mediterranean Sea during the summer period. Despite the Central Mediterranean Sea, the Strait of Sicily in particular, being a key spawning site for many tuna species, little is known on the effects of oceanographic variability on their larval distribution in this area. The abundance and presence-absence of larval specimens for three tuna species (ABT, bullet tuna and albacore) were modeled in order to examine their relationships with environmental factors, by analysing historical in situ information collected during seven annual surveys (2010–2016). The results revealed that most tuna larvae for the three species were found in the easternmost part of the study area, south of Capo Passero. This area is characterized by a stable saline front and warmer nutrient-poor water, and it has different environmental conditions, compared with the surrounding areas. The models used to investigate the presence-absence and abundance of the three species showed that ABT was the most abundant, followed by bullet tuna and albacore. The presence and abundance data collected are comparable with those of other spawning areas in the Mediterranean. Regarding biological and physical parameters, the results suggest that temperature, salinity, and day of the year are the key factors for understanding the ecological mechanisms and geographical distribution of these species in this area. Temperature affects the presence of ABT larvae and salinity, which, with a physical barrier effect, is a key factor for the presence-absence of bullet and albacore and for albacore abundance.

Highlight Bullet tuna ( Auxis rochei Risso 1810) has been identified (measured, weighed) and analyzed. The resource status of bullet tuna has been estimated based on body shape and age group. LWR curve is implemented to describe and express the age group of bullet tuna (immature, adult/mature, old) This study has resulted the composition and ratio of bullet tuna that is suitable to be caught, fit for consumption and worthy of maturation Abstract Bullet tuna ( Auxis rochei Risso 1810) or tongkol lisong (Indonesian) is important for human consumption and health as well as an income source for fishers and coastal communities. Its utilization problems are over exploitation, catch domination by immature groups, and the threatened stock security of the bullet tuna (BLT). This research aimed to determine the status of the prospective parent of bullet tuna caught in the Lesser Sunda region, particularly from the Alas Strait to the Indian Ocean, West Nusa Tenggara (WNT). Meanwhile, the data were collected from July to September 2020 (2 nd transitional season) at the Tanjung Luar Fishing Port, East Lombok and a dependent survey method was adopted with sampling, interview, observation, and documentation techniques. Fork length and body weight data were used to estimate the length and weight relationship, growth pattern, condition factor, fish age group, and catch worth. The primary and secondary data were processed quantitatively using several equations. The growth pattern of bullet tuna was minor allometric ( b = 2.875), worth selling ( K > 1.00), and the majority was adult fish or mature group. The LWR model is . This condition indicates the bullet tuna is worth catching and worth spawning, so that it is eligible to be a potential broodstock candidate to support a sustainable management of BLT fisheries. Furthermore, fishers have applied the code of conduct for responsible fisheries (CCRF) in supporting the sustainable development goals.

Tunas species are considered high migrating species (HMS). In the Mediterranean Sea, there are important areas for the spawning of many of these HMS. The Alboran Sea is an important hotspot for tuna species. Moreover, the Alboran Sea shows important productive areas where the tuna species are concentrated, and, for this reason, the Alboran Sea has been an important fishing area for tuna species since ancient times, which is evidenced by complementary pottery and salting industries’ archaeological findings. Currently, the mainly target tuna species in the Alboran Sea region are bluefin tuna (Thunnus thynnus), little tunny (Euthynnus alletteratus), Atlantic bonito (Sarda sarda), and bullet tuna (Auxis rochei). On the other hand, the North Atlantic Oscillation (NAO) is the most important source of variability, associated with many meteorological variations in the North Atlantic region, affecting wind speed and direction and differences in temperature and rainfall, particularly in winter in the Alboran Sea area. This paper reviews the previous studies about the effects of the NAO on migrating tuna in the Alboran Sea region.

This study was conducted to develop systems for the identification of four tuna species (skipjack tuna Katsuwonus pelamis, yellowfin tuna Thunnus albacares, bullet tuna Auxis sp. and Atlantic bonito Sarda sp). At first, raw samples of these species and a mix intended as internal control were prepared for the authentication of fish muscle tissue of the genus Thunnus sp., Auxis sp. and Sarda sp. DNA from raw muscle tissue, the mix and samples was extracted with the DNeasy mericon Food Kit (Qiagen GmbH, Hilden, Germany). The concentration and purity of DNA in raw samples were evaluated using a spectrophotometer. Primers and probe sequences were specifically designed to identify the selected species. In addition, primers and a probe for the endogenous 12S rRNA gene were designed to determine the presence of amplifiable fish (especially tuna) DNA in samples. Furthermore, the species specificity of the designed primers and probes was verified in DNA samples of various tuna and bonito species. Limit of detection for the selected species was calculated as well as the coefficient of determination R2 and efficiency of real-time PCR testing was determined. To evaluate the developed real-time PCR methods, 70 commercial tuna products were analysed. The results show that mislabelling of fish products can still be encountered and, moreover, the presence of an additional species can be identified.

Highlight Utilization, Growth, and Population of Bullet Tuna (Auxis rochei Risso 1810) in Indian Ocean Southern Sumbawa (2020) Eligibility Status Kawakawa (Euthynnus affinis Cantor, 1849) from Lombok Strait and Indian Ocean Southern Sumbawa (2020) Biological Aspect of Parent Candidate of White-spotted Rabbitfish (Siganus canaliculatus) from Serewe Bay, Lombok Timur District (2020) Study of Sustainability in Management of Malabar Blood Snapper Fisheries in the Indian Ocean Coastal Waters, Sumbawa Regency (2020) Growth Rate and Survivorship of Acropora sp. Fragments that Transplanted on the Artificial Substrate Made from Fly Ash and Bottom Ash (2020) Reproductive Biological Aspect of Panulirus penicillatus in Sumbawa Island Waters, Indonesia (2019) Fisheries Resource Status of Spiny Lobster Panulirus penicillatus in Labangka Waters, South Sumbawa, Indonesia (2019) Growth Rate of Acropora formosa Coral Fragments Transplanted on Different Composition of Faba Kerbstone Artificial Reef (2019) Agribusiness of Edible Jellyfish Crambione mastigophora in Saleh Bay, NTB: Implementation of Sustainable Fisheries (2019) Abstract The Labangka tidal waters, located south of Sumbawa Regency are the habitat and potential fishing ground for lobsters. The dominant species caught by the Labangka fishermen are the Panulirus penicillatus and P. homarus . Fishing pressure is one of the greatest factor influencing the biological and stock condition of lobsters in Labangka. The aim of this study is to determine the key attributes in growth and population parameters. Some attributes whose values are relatively stable compared to that of 2015, consist of conditional factors such as (old age), growth pattern (hypoallometric), growth coefficient (slow growth), exploitation rate (overexploited), and fishing rate (excessive fishing). While, attributes that have improved are carapace length at first capture (CLc) longer than 50% carapace length of infinity (0.5CL∞) and CL rate (CLc/0.5CL∞) reaching more than 1.00 (CLR > 1.00). In implementing sustainable management of spiny lobster for fishery resources, improvisation is needed in place of catching technologies. One of the recommendation is to add more fishing vessel (Lboat > 17.0 m) equipped with engines that are able to reach potential fishing ground in the west waters of Cemplung beach, Labangka.

Fish processing industry generates a considerable amount of by‐products which represent an environmental problem. Only a small portion of these residues is used for the production of low marketable products. Therefore, industrially scalable processes yielding value‐added products would be highly desirable. Different to others studies, this work deals with potential valorisation of bullet tuna (Auxis rochei) viscera using its endogenous enzymes without previous separation stage for the production of bioactive hydrolysates. Functional and bioactive properties of hydrolysates produced at different degree of hydrolysis (DH 3%, 6% and 9%) were evaluated. The endogenous enzyme hydrolysates (EH) obtained by the proposed low cost treatment were compared with hydrolysates produced with a well‐known commercial enzyme: subtilisin. Regarding functional properties, EH presented similar or even better solubility, emulsifying and oil binding capacities than subtilisin hydrolysate (SH). EH also showed very interesting antioxidative properties, particularly metal reducing and radical scavenging activity. Additionally, the ACE inhibitory activity of EH at low degree of hydrolysis was comparable to SH. According to these results, bullet tuna viscera protein can be value‐added by endogenous enzyme hydrolysis.

The present study deals with the isolation of sulfated polysaccharides (Ps) from the Bullet tuna by-products (head, skin and bones). Results of chemical characterization revealed that Ps-bones showed the highest total sugar, uronic acid and sulfate group contents. Tuna extracted-Ps contained a mixture of neutral sugars, with high amounts of glucuronic and galacturonic acids and presented different molecular weights. The presence of sulfate groups in different Ps was confirmed by FTIR analysis. Interestingly, Ps-bones showed the highest antioxidant activity among all the extracted Ps. Moreover, results revealed that all polysaccharides displayed varying degrees of antibacterial activity. Ps-bones exhibited high and wide spectrum of activities, inhibiting the growth of all bacteria tested. Ps-bones incorporated during fillet cooking offered an excellent protection of fish fillet by avoiding pH change, color loss, lipid oxidation and spoilage. Overall, the results demonstrated that Ps could be potentially used as natural antioxidant and antibacterial agents.

Hook and line fishing has been used for the last two decades along the Vizhinjam Coast targeting mainly tunas especially bullet tuna. The fishing methodology is in use for more than several decades, but systematic study in relation to the modifications in fishing practice and its impact on the improvement in catch and income generation of fishermen has not yet been done. This paper aims to bring out the modifications in the gear/ craft and area of operation of line fishery and its impact on the income generation of fishers in the Vizhinjam Coast.

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.

Several studies have confirmed that the North Atlantic Oscillation (NAO) has a direct effect on tuna across a range of biological aspects, such as abundance, catchability, recruitment, and physical condition (LC), especially during winter season (NAOw). However, its effect on reproductive biology has been barely investigated. Thus, the main aim of this study was to investigate the effect of the NAO on the physical condition index and gonadosomatic index (GSI) of the three most commercially exploited small species of migrating tuna (i.e. little tunny, bullet tuna, and Atlantic bonito) in the Mediterranean Sea. A positive direct correlation was found between little tunny and Atlantic bonito and the gonadosomatic and the physical condition indexes. In addition, a strong correlation was found between the NAOw and the gonadosomatic and LC indexes, which could lead to higher reproductive investment in gonad growth before the spawning season. In contrast, bullet tuna had a low LC index during peak gonad growth and were less affected by NAOw oscillations. In the case of bullet tuna, these results could be explained by a longer reproductive period that would lead to faster fat consumption before the reproductive period than in the other species considered and greater dependence on the surrounding environmental conditions for reproductive success., Sí

An oceanographic survey was carried out during the summer of 2009, from June 25 to July 3 in the Gulf of Gabes. The study area is characterized by a wide continental shelf. A plankton sampling scheme was carried out to study the structure of the larval fish assemblages that characterizes the surface mixed layer, and to assess the influence of the environmental parameters on their spatial distribution. A total of 36 taxa were identified, 3 classified to the level of genus, 5 to family and 28 to species. The majority of identified fish larvae belonged to demersal species, mainly picarel Spicara smaris (23.76% of the total larval fish abundance), followed by red mullet Mullus barbatus (14.92%) and several species of the Sparidae family (9.15%). Small pelagic species as Sardinella Sardinella aurita and European anchovy Engraulis encrasicolus were also abundant (27.75 %) and dominated the fish larvae community in offshore stations. Five large pelagic species were found among the larvae, including bullet tuna Auxis rochei, Atlantic black skipjack Euthynnus alletteratus, albacore Thunnus alalunga, swordfish Xiphias gladius and the highly migratory Atlantic bluefin tuna Thunnus thynnus. All these apex predator species appear in 38.5% of the sampling stations and contribute about 7.9% of the total larval catches. The larval fish assemblage of the Gulf of Gabes is predominantly composed of neritic species in correspondence with the shallow depths of the study area. Canonical Correspondence Analysis (CCA) showed that larval distributions were mainly conditioned by depth. However, other factors, like hydrographic processes, play also a very important role in shaping the spatial pattern of larval fish distribution, SI

The bullet tuna Auxis rochei, the little tunny Euthynnus alletteratus, and the Atlantic Chub mackerel Scomber colias are three small Scombridae with similar life-history traits such as overlapping epipelagic distribution and a shared spawning area in Tunisian waters. In this study, we compared the phylogeography and demographic histories of these species by analyzing the sequence variability of the mitochondrial DNA control region. None of the species showed genetic differentiation in their Tunisian distribution; however, we inferred three completely different population histories. E. alletteratus showed a demographic history of a very recent bottleneck followed by sudden population expansion probably consequence of a population decline in the Last Glacial Maximum. S. colias also presented a population expansion after collapse but in this case about ten-fold older than that observed in E. alletteratus. Finally, A. rochei presented a history of demographic stability. These contrasting population histories were discussed based on their possible differences in life-history traits, but the hypothesis of stochastic factors affecting the demography of these species was also invoked.

BACKGROUND In spite of the many studies performed over the years, there are still problems in the authentication of closely related tuna species, not only for canned fish but also for raw products. With the aim of providing screening methods to identify different tuna species and related scombrids, segments of mitochondrial cytochrome b (cyt b) and nuclear parvalbumin genes were amplified and sequenced or subjected to single-strand conformation polymorphism (SSCP) and restriction fragment length polymorphism (RFLP) analyses. RESULTS The nucleotide diagnostic sites in the cyt b gene of five tuna species from Indonesia were determined in this study and used to construct a phylogenetic tree. In addition, the suitability of the nuclear gene that encodes parvalbumin for the differentiation of tuna species was determined by SSCP and RFLP analyses of an intron segment. RFLP differentiated Thunnus albacares and from T. obesus, and fish species in the Thunnus genus could be distinguished from bullet tuna (Auxis rochei) by SSCP. CONCLUSIONS Parvalbumin-based polymerase chain reaction systems could serve as an additional tool in the detection and identification of tuna and other Scombridae fish species for routine seafood control. This reaction can be performed in addition to the cyt b analysis as previously described. © 2015 Society of Chemical Industry

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Auxis rochei is one of genus Auxis and widely distributed in tropical and subtropical waters. In this study, we described the complete mitochondrial genome of A. rochei. The genome is 16505 bp in l...

Bullet tuna is considered as one of the important species for tuna purse seine fisheries in Indonesia, especially in archipelagic waters. However, little is known about its biological characteristics which proven to be pivotal in stock assessment. The purpose of this research was to determine some of the biological stock indicators for bullet tuna (Auxis rochei) from Banda Sea and its adjacent waters. The study was conducted from February to November 2016. The length of the bullet tuna caught were in between 18.5-32.7 cmFL (mode=24 cmFL). Growth pattern was isometric with b=3.01 and R2=0.84 Sex ratio was balanced between male and female (1:1). The spawning season allegedly from June to November. The length at 50% mature (L50) was 23.6 cmFL. A good indicator for the fisheries, where at least 75% of the mature fish caught were already spawned. The asymptotic length (L) was 33.63 cmFL, with coefficient of growth (K) around 0.73/year. Natural mortality (M) estimated at 1.87/year, fishing mortality (F) estimated at 2.20/year and total mortality (Z) was 4.07/year. The exploitation level (E) was estimated to be at maximum level (E=0.54/year), for precautionary purpose, the number of efforts should be reduced down to 8% from current effort.

Pelagic fishes such as bullet and frigate tuna in the Indian Ocean were caught in Indian Ocean of Indonesian jurisdiction using various fishing gears including, drifting gillnet and landed in various fishing port in along coastal of west Sumatera (Banda Aceh, Pariaman, Bungus/Padang and Painan) as well as south Java, Bali and Nusatenggara (Muarabaru/Jakarta, Pelabuhanratu, Cilacap, Kedonganan, Benoa). In Cilacap, tuna drifting gillnet fishery is fishing bullet and frigate tuna as by product. The current work describes the catch and size distribution of bullet tuna (Auxis rochei Risso, 1810) and frigate tuna (Auxis thazard Lacepède, 1800) caught by drifting gillnet based at Cilacap Fishing Port. Data and information obtained through catch monitoring, port sampling and landing report of Cilacap Fishing Port 2011 as well as from Capture Fisheries Statistics of Indonesia 2010. The catch estimation of bullet and frigate tuna on drifting gillnet fishery is about 3.220 and 47.346 tons respectively. The catch rate of drifting gillnets on the frigate tuna was 0.364 mt/trip in 2006 decreased to 0.054 mt/trip in 2011 (decreased average 17% per year). The catchrate of drifting gillnets on the bullet tuna was also decreased from 0.178 mt/trip in 2006 to 0.013 mt/ trip in 2011. The FL of bullet and frigate tuna ranged respectively between 16-39cm and 25-46cm. Both species were mostly caught by drifting gillnet in adult size condition.

An indirect enzyme-linked immunosorbent assay (ELISA) has been developed for the identification of albacore (Thunnus alalunga) and its differentiation from other less-valued scombrid species such as yellowfin tuna (Thunnus albacares), bullet tuna (Auxis rochei), atlantic bonito (Sarda sarda), bigeye tuna (Thunnus obesus), little tunny (Euthynnus alleteratus) and skipjack tuna (Katsuwonus pelamis). The assay uses polyclonal antibodies raised in rabbits against soluble muscle protein extract from fresh albacore. These polyclonal antibodies were rendered species-specific by blocking them with the heterologous soluble muscle proteins, allowing discrimination between fresh albacore and the rest of the scombrid species, except for yellowfin tuna. A total of 40 commercial albacore fresh and frozen fillets were analysed, revealing an incorrect labelling in 32.5% of the albacore samples. However, positive samples (67.5%) could be albacore or yellowfin tuna and should require a DNA assay as discriminatory technique.

Knowledge of population structure of species is needed to establish appropriate management regulations. Of particular concern are those commercial species; these exploited fish populations can undergo loss of genetic variability that ultimately may lead the loss of regional small populations. This situation could occur in the small tuna species, which in some cases are heavily targeted by artisanal fisheries. Here, we focused on the Bullet tuna (Auxis rochei) with an extensive sampling (n = 431) along the north and south coast of the west Mediterranean and one location on the east Atlantic. The analysis of the mtDNA control region revealed that seven (about 1.6%) individuals were not identified as Bullet tuna suggesting a species misidentification with possible implications in stock assessment. Population genetics results showed clear genetic differentiation between the Iberian Peninsula and North African locations. These results have a clear impact on the conservation and management strategies, and if it is confirmed in other small pelagic species, the pattern of population structure in the Mediterranean is more complex than initially expected.

The trophic ecology of bluefin tuna larvae (Thunnus thynnus) from the Balearic Sea, together with its co-existing tuna species such as albacore (T. alalunga), bullet (Auxis rochei) and little tunny (Euthynnus alletteratus) were examined by nitrogen and carbon stable isotope analyses. A total of 286 larvae were analyzed for this study, of which 72 larvae corresponded to bluefin, 57 to albacore, 81 to bullet tuna and 76 to little tunny. Tuna larvae were separated into the pre-flexion and post-flexion developmental stages. Within the size 3–9 mm standard length (SL), the stable isotope of nitrogen (δ15N) showed significant differences between species where bluefin tuna larvae ranked highest. Pre-flexion bluefin tuna and little tunny larvae showed significantly higher δ15N signatures than the post-flexion larvae. This effect is attributed to a biochemical trace of maternal δ15N signatures. However, neither albacore nor bullet tuna larvae showed this pattern in δ15N signatures, possibly owing to a compensation effect between lower maternal δ15N values transmitted to pre-flexion larvae and the early increase of δ15N values in post-flexion stages. One way ANOVA showed significant differences between species in the stable isotope ratio of carbon (δ13C) values, which suggests specific differences of carbon sources. Furthermore, a similar significant ontogenic effect between δ13C signatures of pre-flexion and post-flexion larvae is also evidenced in all four species. At pre-flexion stages, all species except bullet tuna larvae showed significant negative relationships between δ15N and larval standard length. At post-flexion stages, a significant linear relationship with larval size was only observed in albacore and bullet tuna larvae indicating a possible trophic shift towards early piscivory. With respect to δ13C values with larval size, all four species showed significant linear decreases. It may be explained by the metabolism of growth of somatic mass subject to modification of the relative carbon isotopic sources. In conclusion, the species' signatures of δ15N and δ13C indicate differentiated early life trophic niches. In addition, it is worth remarking the potential use of transgenerational isotopic transmission in future research applications, SI

Climate oscillations exert direct control over the environment in which they occur and may influence the physical condition of migratory marine species, such as tuna, as reported by several authors. The main aim of thisstudywastoexploretheassociationbetweenthepotentialeffectsoftheNorthAtlanticOscillation(NAO)on thefitness condition of bullet tuna (Auxis rochei) migrating to the Spanish Mediterranean Sea. A total of 2357 length-weight pairs of data obtained from individuals collected on the Spanish Mediterranean coast were analysed. A non-parametric Spearman test was used to investigate correlations between the atmospheric oscillation indexes and two physical condition indexes. The results suggest that, in general, positive phases of the NAO index improve the physical condition offish migrating to spawning grounds in the Mediterranean Sea. These results could be explained by changes in the dominant winds, which could favour pre-spawning migration, and by nutrients availability, which guarantees their recovery after the spawning period., SI

International audience; During routine monitoring of commercial purse seine catches in 2011, 87 fingerling specimens of scombrids were collected in the southern Adriatic Sea. Sequencing of the mitochondrial DNA control region locus inferred that specimens belonged to the Atlantic bluefin tuna, Thunnus thynnus (Linnaeus, 1758) (N = 29), bullet tuna, Auxis rochei (Risso, 1810) (N = 30) and little tunny, Euthynnus alletteratus, Rafinesque, 1810 (N = 28). According to previously published growth parameters, the age of the collected specimens was estimated at approximately 30–40 days, suggesting they might have been spawned in the Adriatic Sea, contrary to the current knowledge. A coupled modelling system with hydrodynamic (ROMS) and individual based model (IBM—Ichthyop) was set up to determine the location of the spawning event. Numerical simulations with the IBM model, both backward and forward in time, indicate commercial tuna cages in the middle Adriatic coastal area as possible spawning location. The two other non-commercial species likely opportunistically use the positive environmental (abiotic and biotic) conditions to spawn in the same area.

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Early life stages of tuna species were investigated along the northern coasts of Tunisia in the summer of 2010, from 7 to 14 July. A total of 74 stations, distributed on a regular grid, were sampled. Larvae of five tuna species were identified: the Atlantic bluefin tuna, the bullet tuna, the Atlantic black skipjack, the Atlantic bonito and the albacore tuna. Larval distribution patterns show that Atlantic bluefin tuna and albacore tuna usually spawn in offshore oligotrophic waters and Atlantic black skipjack larvae on the continental shelf. The widespread distribution of bullet tuna larvae, suggests that it spawns on the entire continental shelf and over the shelf break. The results from the quotient analysis carried out to characterize the spawning habitat of each species, show that the input of recent surface Atlantic water (AW) masses play a key role in the spawning strategy of tuna species, particularly in the case of the Atlantic bluefin tuna, whose larvae were mainly caught in the mixed waters resulting from the interaction between recent AW and resident AW, as demonstrated by their preference for salinity values between 36.9 and 37.4., Se investigaron las fases larvarias tempranas de especies de túnidos a lo largo de las costas del norte de Túnez, durante el verano de 2010, del 7 al 14 de julio. Se muestrearon un total de 74 estaciones, distribuidas en una malla regular. Se identificaron larvas de cinco especies: el atún rojo, la melva, la bacoreta, el bonito y el atún blanco. Los patrones de distri-bución de larvas muestran que el atún rojo y el atún blanco desovan generalmente en aguas oligotróficas alejadas de la costa. Por contra, la localización relativamente más costera de las larvas de bacoreta indica que esta especie se reproduce sobre la plataforma continental, mientras que la amplia distribución de las larvas de melva sugiere que esta especie desova a lo largo de toda la plataforma y el margen continental. Los resultados del análisis de proporcionalidad, llevado a cabo para caracteri-zar el hábitat de puesta de cada especie, muestran que la entrada de masas de agua superficial atlántica (AW) reciente juegan un papel clave en la estrategia de desove de las especies de túnidos, sobre todo en el caso del atún rojo, cuyas larvas fueron capturadas principalmente en las aguas de mezcla, resultantes de la interacción entre el AW reciente y la residente, como lo demuestra su preferencia por los valores de salinidad entre 36.9 y 37.4., SI

1. This study examines changes in frigate tuna populations in southern Sri Lanka, based on reports from fishers in three age classes. Significantly higher values for best day's catch and largest specimen ever caught were obtained by older fishers than younger ones. Values were also significantly higher during early years, providing clear evidence of a decrease in the resource over time (1951-2007). 2. Older fishers reported best catches further inshore and in shallower waters which, on becoming depleted, forced younger generations to fish in less exploited areas further offshore. Heavy harvesting is also evident from the significantly greater number of sites reported by older fishers as being depleted, compared with observations of younger fishers. 3. These findings contrast markedly with catch and catch per effort patterns from statistics for frigate tuna and bullet tuna (combined) in southern Sri Lanka (1994-2004). No stock decline is evident, and at least one report in the early 1990s advocated increasing exploitation rates by 40% to maximize yields. 4. Although not a primary research objective, fisher observations on frigate tuna populations were also analysed to help evaluate possible effects of the 2004 tsunami. Most fishers reported post-tsunami decline, but mainly from a larger new generation of fishers, rather than extra boats provided by aid money or (direct or indirect) biophysical impacts from the tsunami. 5. Reliance on fishery statistics, especially for mixed species and over a limited period, can be risky and easily mask true stock status. Evidence of harvesting effects on frigate tuna in southern Sri Lanka is evident using questionnaire data over a longer time scale. 6. This study provides another compelling case of the 'shifting baseline syndrome', whereby. shers of different ages have altered perceptions/experiences of their environment. This may be its first reported occurrence in Sri Lanka. Traditional knowledge from this and similar surveys may provide national fishery management with valuable insights and help improve conservation prospects for frigate tuna and other marine resources. Copyright (C) 2009 John Wiley & Sons, Ltd.

大部分が廃棄されているマルソウダ煮熟水の有効利用として，飼料へのマルソウダ煮熟水添加がブリ幼魚の成長へ与える影響を評価した。試験飼料として魚粉を主タンパク質源とした FM 飼料と FM 飼料中の魚粉の 30% を大豆油粕（SBM）で代替した SBM 飼料，それらにマルソウダ煮熟水（Broth）を加えた飼料を調整して 6 週間給与した。試験終了時の成長成績は，FM+Broth 区>FM 区>SBM+Broth 区>SBM 区の順であった。以上のことから，飼料へのマルソウダ煮熟水の添加は，ブリ幼魚において成長を改善すると考えられた。

The complete mitochondrial DNA sequence of the frigate tuna Auxis thazard and two divergent mitotypes (Mitotype I and Mitotype II) of the bullet tuna Auxis rochei have been determined. The total length of the mitogenomes was 16,506, 16,501 and 16,503 bp, respectively. All mitogenomes had a gene content (13 protein-coding, 2 rRNAs and 22 tRNAs) and organization similar to those observed in most other vertebrates. The major non-coding region (control region) ranged between 843 and 847 bp in length, and showed the typical conserved blocks. Phylogenetic analyses revealed a monophyletic origin of Auxis with respect to other tuna fish. Molecular data here presented provide a useful tool for evolutionary as well as population genetic studies.

The identification and mitigation of adverse effects of the bycatch of tuna longline fishery have been mainly developed and implemented for seabirds, sharks and turtles and, the knowledge on teleost bycatch for this fishery, remains very poor. This paper contributes to a comprehensive assessment of life history traits and fishery attributes of target and bycatch species caught by the tuna longline fishery in the South Atlantic and Indian Oceans. Data was compiled on seven life history traits and three fishery attributes for 33 and 27 teleost stocks caught by longliners in South Atlantic and Indian Oceans, respectively. In addition, each species was assigned into four categories describing the fate of the catch: target species for commercial use, bycatch species kept for consumption, bycatch species kept for commercial use and discarded bycatch. Life history traits and fishery attributes did not differ between oceans. However, non-target but commercialized species were smaller in the Atlantic Ocean. Teleosts caught by the tuna longline fishery was segregated into three main groups: (1) the fast growing species represented mainly by dolphinfishes (Coryphaena hippurus and C. equisellis), skipjack tuna (Katsuwonus pelamis), kawakawa (Euthynnus affinis), bullet tuna (Auxis rochei), snoek (Thyrsites atun) and blackfin tuna (Thunnus atlanticus); (2) target tunas and most other bycatch species which were part of an intermediate group and (3) billfishes including swordfish representing the large and slow growing species with moderate to high market values and unknown or highly uncertain stock status. Investment in some key life history traits (such as growth coefficient) and the development of quantitative or semi-quantitative approaches (stock assessment and Ecological Risk Assessment) should be priorized as precautionary management measures for these species.

The marine environment of the Santa Marta region (Colombian Caribbean) is unique in many ways. The coexistence there of both species of Auxis is herewith reported and discussed. Auxis thazard, the frigate tuna or frigate mackerel, has been reported several times from Santa Marta; however, the occurrence of A. rochei, the bullet tuna or bullet mackerel, is reported for the first time. Some inter and intraspecific differences are discussed; fishery aspects are commented as well.

Small juveniles of the nine species of scombrids in Australian waters are morphologically similar to one another and, consequently, difficult to identify to species level. We show that the sequence of the mitochondrial DNA cytochrome b gene region is a powerful tool for identification of these young fish. Using this method, we identified 50 juvenile scombrids collected from Exmouth Bay, Western Australia. Six species of scombrids were apparent in this sample of fish: narrow-barred Spanish mackerel (Scomberomorus commerson), Indian mackerel (Rastrelliger kanagurta), frigate tuna (Auxis thazard), bullet tuna (Auxis rochei), leaping bonito (Cybiosarda elegans), and kawakawa (Euthynnus affinis). The presence of Indian mackerel, frigate tuna, leaping bonito, and kawakawa is the first indication that coastal waters may be an important spawning habitat for these species, although offshore spawning may also occur. The occurrence of small juvenile S. commerson was predicted from the known spawning patterns of that species, but other mackerel species (Scomberomorus munroi, Scomberomorus queenslandicus, Scomberomorus semifasiciatus) likely to be spawning during the sampling period were not detected among the 50 small juveniles analyzed here.

A total of 235 bullet tunas (Auxis rochei) was caught off the north-eastern coast of Sicily between March 2003 and March 2004 for the purpose of studying their feeding habits. The fish were caught by means of an experimental surface gill-net during fishing surveys carried out on a monthly basis. The stomach contents were analysed and the prey identified, counted and weighed. The importance of the different prey types was assessed utilizing several feeding indices while possible size-related changes of the diet composition were highlighted by means of hierarchical cluster analysis, nMDS and SIMPER analysis. The results of this study showed that the bullet tuna is an epipelagic off-shore predator feeding on whatever abundant resource is available in the environment with a preference for planktonic crustaceans, small cephalopods and fish larvae. Among crustaceans, hyperiidean amphipods were the most important prey, with Anchylomera blossevillei as the dominant species, followed by the euphausiacean Stylocheiron maximum. Among cephalopods, Heteroteuthis dispar was recorded frequently while fish larvae showed high values of all indices. All prey were pelagic organisms. A size-related change in the diet composition was observed, even if it seemed related to the temporal fluctuations of the zooplanktonic assemblage in the environment. The average prey weight per stomach increased significantly in the larger predators which mostly fed on fish larvae belonging to several commercially important demersal and pelagic species.