Search

Growth directly influences production rate and therefore is one of the most important and well-studied traits in animal breeding. However, understanding the genetic basis of growth has been hindered by its typically complex polygenic architecture. Here, we performed quantitative trait locus mapping and genome-wide association studies for 10 growth traits that were observed over 2 years in 1,100 F1 captive-bred trevally (Pseudocaranx georgianus). We constructed the first high-density linkage map for trevally, which included 19,861 single nucleotide polymorphism markers, and discovered 8 quantitative trait loci for height, length, and weight on linkage groups 3, 14, and 18. Using genome-wide association studies, we further identified 113 single nucleotide polymorphism-trait associations, uncovering 10 genetic hot spots involved in growth. Two of the markers found in the genome-wide association studies colocated with the quantitative trait loci previously mentioned, demonstrating that combining quantitative trait locus mapping and genome-wide association studies represents a powerful approach for the identification and validation of loci controlling complex traits. This is the first study of its kind for trevally. Our findings provide important insights into the genetic architecture of growth in this species and supply a basis for fine mapping quantitative trait loci, genomic selection, and further detailed functional analysis of the genes underlying growth in trevally.

Gorgorhynchoides pseudocarangis n. sp. (Isthmosacanthidae), is described from the intestine of the white trevally Pseudocaranx dentex (Bloch & Schneider) (Carangiformes: Carangidae) collected in Moreton Bay, Queensland, Australia. The new species has a proboscis armature of 27–28 rows of 16–17 hooks. It is most similar morphologically to Gorgorhynchoides bullocki Cable & Marafachisi, 1970 and Gorgorhynchoides gnathanodontos Smales, 2014 but differs from the former in having a longer proboscis with more rows of hooks, ventral hooks 6/7–12 with notched tips and trunk spines which do not extend onto the anterior bulbous swelling, and from the latter in having a longer proboscis, ventral hooks 6/7–12 with notched tips, more circles of trunk spines, larger eggs and a proboscis armature with all hooks lacking manubria. Previous molecular phylogenetic analyses have shown that the genus Serrasentis Van Cleave, 1923 is sister to Gorgorhynchoides Cable & Linderoth, 1963, although some have failed to resolve these two lineages in separate monophyletic clades. We performed novel single-gene and concatenated phylogenetic analyses using cox1 mtDNA, 18S and 28S rDNA gene-sequences, resolving Gorgorhynchoides and Serrasentis in monophyletic sister clades and demonstrating that Gorgorhynchoides pseudocarangis n. sp. is phylogenetically distinct from related species for which molecular sequence data are available. We view the previous amendment of the Isthmosacanthidae to include the genera Golvanorhynchus Noronha, Fabio & Pinto, 1987, Gorgorhynchoides, Isthmosacanthus Smales 2014 and Serrasentis, and the transfer of the family to the Polymorphida, as the most satisfactory classification at present, although additional molecular evidence would provide greater stability.

Antimicrobial peptides (AMPs) are biologically active molecules involved in host defense present in a variety of organisms. They are an integral component of innate immunity, forming a front line of defense against potential pathogens, including antibiotic-resistant ones. Fishes are proven to be a prospective source of AMPs as they are constantly being challenged by a variety of pathogens and the AMPs are reported to play an inevitable role in fish immunity. Among them, β-defensins form one of the most studied multifunctional peptides with early evolutionary history and recently being considered as host defense peptides. The present study highlights the first-ever report on β-defensin AMP sequences from common goby (Pomatoschistus microps) and silver trevally (Pseudocaranx georgianus). A 192 bp cDNA fragment with an open reading frame encoding 63 amino acids (aa) comprising a 20 aa signal peptide region at the N-terminal was obtained from the mRNA of gill tissue of both P. microps and P. georgianus by RT-PCR. These peptide sequences when characterized in silico at the molecular level revealed a 43 aa cationic mature peptide with the signature intra-molecular disulphide bonded cysteine residue pattern ascertaining its β-defensin identity, further confirmed by phylogenetic analysis. The data collected will pave the way for further research on varied facets of the peptide-like, tissue level expressions, antimicrobial activities on commonly encountered pathogens, and its feasibility as a therapeutant in the aquaculture scenario.

Pseudocaranx dentex (white trevally) which belongs to the Carangidae family, is an important commercial fishery and aquaculture resource in Asia. However, its evolution and population genetics have received little attention which was limited by the mitogenome information absence. Here, we sequenced and annotated the complete mitochondrial genome of P. dentex which was 16,569 bp in length, containing twenty-two tRNAs (transfer RNAs), thirteen PCGs (protein-coding genes), two rRNAs (ribosomal RNAs), and one non-coding region with conservative gene arrangement. The Ka/Ks ratio analysis among Carangidae fishes indicated the PCGs were suffering purify selection and the values were related to the taxonomic status and further influenced by their living habits. Phylogenetic analysis based on the PCGs sequences of mitogenomes among 36 species presented three major clades in Carangidae. According to the phylogenetic tree, we further analyzed the taxonomic confusion of Carangoides equula which was on the same branch with P. dentex but a different branch with Carangoides spp. We inferred Kaiwarinus equula should be the accepted name and belong to the independent Kaiwarinus genus which was the sister genus of Pseudocaranx. This work provides mitochondrial genetic information and verifies the taxonomic status of P. dentex, and further helps to recognize the phylogenetic relationship and evolutionary history of Carangidae.

Pseudocaranx dentex (Schneider, 1801) Caranx dentex: Golani & Ben-Tuvia, 1986. Pseudocaranx dentex: Golani, 1996; Golani, 1997 (Heb.); Golani, 2005; Frid, 2015 (Fish.)., Published as part of Golani, Daniel, 2021, An updated Checklist of the Mediterranean fishes of Israel, with illustrations of recently recorded species and delineation of Lessepsian migrants, pp. 1-108 in Zootaxa 4956 (1) on page 50, DOI: 10.11646/zootaxa.4956.1.1, http://zenodo.org/record/4691195, {"references":["Golani, D. & Ben-Tuvia. A. (1986) New records of fishes from the Mediterranean coast of Israel including Red Sea immigrants. Cybium, 10, 285 - 291.","Golani, D. (1997) Handbook of the Fishes of Israel. Keter Publishing House Ltd. Jrusalem. 269 pp. [in Hebrew].","Frid, O. (2015) Gear selectivity and seasonality in Israeli gill and trammel net fisheries. M. SC. thesis. University of Tel-Aviv, 58 + 2 pp."]}

Pseudocaranx dentex (Bloch & Schneider 1801) ���White trevally Taxonomy. First record from Lebanon as Caranx dentex (Schneider) by Mouneimn�� (1977: 63); subsequently recorded as Caranx dentex (Schneider 1801) by Mouneimn�� (2002: 142���143). Recent unpublished records from Beirut (9 December 2009, 5 June 2011 and 5 September 2012). Material in collection: AUBM. Distribution. Nearly circumglobal in warm temperate seas (including Mediterranean Sea), but not in eastern Pacific. Conservation. IUCN: Global (LC: 10 May 2013); Med. (NE). Capture and threats: FIT, FIB, HAB, NIS, unknown. Occurrence: Rare. Low priority for conservation action., Published as part of Bariche, Michel & Fricke, Ronald, 2020, The marine ichthyofauna of Lebanon: an annotated checklist, history, biogeography, and conservation status, pp. 1-157 in Zootaxa 4775 (1) on page 61, DOI: 10.11646/zootaxa.4775.1.1, http://zenodo.org/record/3983887, {"references":["Mouneimne, N. (1977) Liste des poissons de la cote du Liban (Mediterranee orientale). Cybium, 3 (1), 37 - 66.","Mouneimne, N. (2002) Poissons marins du Liban et de la Mediterranee orientale. INCAM-EU / CNRS Lebanon, Beyrouth, 271 pp."]}

The white trevally (Pseudocaranx dentex Bloch & Schneider, 1801) is a widely distributed carangid, commercially exploited in both the Pacific and eastern Atlantic. Most published works refer to the use of hormonal induction with gonadotropin-releasing hormone for egg supply with generally low fecundities and of poor quality. This study aimed to contribute for a better knowledge on the husbandry conditions that allow for natural spawning of white trevally in captivity. Wild white trevallies were kept in captivity for four years until natural spawning occurred. Nine breeders were kept in a 10m3 concrete tank at a density of 5 Kg/m3, under natural photoperiod and natural water temperature fluctuations. Spawning started when water temperature reached 19 °C and lasted for two months. Viability rates varied between 35 and 79% and the average number of spawned eggs per female was of 280 × 103. Egg total lipids (16%DW) and fatty acid profile (expressed as a % total detected) remained constant throughout the spawning season and were not correlated with any egg viability parameters. Neutral lipids, a major energy source in marine fish eggs and larvae, accounted for 50% of lipid classes, followed by glycolipids and phospholipids. Within lipid fractions, the neutral lipids presented high amounts of monounsaturated fatty acids followed by equally high contents of polyunsaturated fatty acids. Docohexaenoic acid (DHA) was mainly found in the phospholipids fraction, though it was present in high amounts in all lipid classes. However, no significant correlations were observed between the DHA content and the egg viability parameters. The percentage of arachidonic acid (Ara) (

The discovery and identification of species is fundamental to the documentation, conservation and management of biodiversity. The taxonomy of the antitropical Pseudocaranx dentex complex (Carangidae) is confused and inconsistently reported. Previous morphological analyses concluded that this complex consisted of three species, namely P. sp. ‘dentex’, P. georgianus and P. dinjerra, in Australian waters. This study used genetic (COI sequence) and morphological data to evaluate the validity of this conclusion. The COI data showed the presence of three discrete lineages within this complex, which appear to correspond to the above-mentioned three species. They also suggested that P. sp. ‘dentex’ is closely related to, and possibly the same species as, P. dentex from southern Africa and the Mediterranean Sea. Also, the extent of morphological and geographical overlap between P. georgianus and P. dinjerra was greater than previously documented which, uncorrected, could lead to identification errors and present challenges for monitoring and management of harvested stocks of these species. By answering important taxonomic questions, our results will facilitate the proper interpretation of the results of past studies and the design of future studies of the P. dentex complex. They have also highlighted the value of molecular data for identifying species in morphologically conservative taxa.

Knowledge of connectivity and population structure is integral to the sustainable management of fished populations, yet such information is unavailable for many species over scales relevant to their exploitation. We examined broad-scale patterns and drivers of adult movement for a putatively mobile carangid (Pseudocaranx georgianus) on Australia’s southeast coast using an angler tag-recapture dataset. More than 6300 individuals were tagged and released across 1007 km of coastline, with anglers recapturing 157 (2.48%) individuals during a 14-year period. Median distance moved was 5 km and a substantial proportion of individuals (19%) were recaptured at their release location. Recapture latitude was also strongly predicted by release latitude (r2 = 0.87). However, a broad range of movements were observed (0–508 km), with 6% of individuals moving further than 100 km. Most individuals recaptured in areas now designated as Marine Protected Areas (MPAs) were originally released in the same area (79.2%). Larger body size, longer periods at liberty, and releases during Spring all positively influenced distance moved. Results support restricted movement over an intermediate scale, punctuated by occasional large movements. Our findings suggest adult movement of P. georgianus in southeastern Australia primarily occurs over smaller distances than the current spatial scale of management.

International audience; Length–weight relationships are presented for 33 fish species from New Zealand. The parameters a and b of the equation W = aLb were estimated. Parameter b ranged from 2.51 (Pseudocaranx dentex) to 3.51 (Alepocephalus antipodianus) with a mean of 3.12 ± 0.24. Most of these estimates (90.9%) were between 2.8 and 3.4. Maximum lengths and depths of catch are updated for nine species.

Specimens of the three new fish species were recorded during 2015 and 2016 in the River Neretva Estuary. These species are: White trevally, Pseudocaranx dentex (Bloch and Schneider, 1801), Pilotfish, Naucrates ductor (Linnaeus, 1758) and White grouper, Epinephelus aeneus (Geoffroy Saint–Hilaire, 1817). The characteristics of caught specimens and their history of records in Adriatic Sea are described. Potential impact of new species invasion in the Neretva Estuary as a major Eastern Adriatic nursery habitat is discussed.

Marine fish, hoki (Macruronus novaezealandiae), kahawai (Arripis trutta) and trevally (Pseudocaranx dentex) were used to develop fermented fish models to emulate Asian examples. The formulations comprised ground fish, carbohydrate, garlic and salt, but no added culture. The carbohydrate was cooked rice or glucose. The mixtures were extruded into open-ended 50 mL plastic syringes, sealed and incubated at 30℃ for 96 h. The syringe piston was progressively advanced to yield test samples. The endogenous lactic acid bacteria were capable of fermenting glucose, but not cooked rice. After glucose fermentation, the treatments contained around 8.7 log cfu·g-1 (from 3.3) with the pH range of 4.38 to 5.08 (from around 6.3), depending on the species. Hardness, springiness and cohesiveness of treatments all increased with fermentation, except for hoki, which was subject to an endogenous proteolytic activity. Color development varied with species: light reflectance (L*) of the trevally and kahawai treatments increased, while the a* (redness) and b* (yellowness) values were static. Hoki exhibited the least color changes except for yellowness, which increased markedly. Possible reasons for this are discussed. Proteolysis was greatest for trevally. Lipid oxidation was least for hoki, notably the species with the lowest fat content. The trevally treatment generated the highest concentration of amines, but values were lower than reported for fermented fish sausage in Asia, possibly because of raw material hygiene status. The physiochemical outcomes indicated that trevally (as pieces unsuited for sale as fillets) would be best suited to this food product class. Suitable species could be identified in other fisheries.

Physoclistous fish are unable to rapidly ascend through the water column without significant risk of barotrauma via swim bladder hyperextension or rupture. Here, we report on the discovery of a highly specialised anatomical structure which permits some physoclistous fish species, the samson fish Seriola hippos and silver trevally Pseudocaranx georgianus, to vent swim bladder gas during ascent. Dissections of injected casts and X-ray imaging revealed the swim bladder ‘vent’ to consist of a membranous opening in the roof of the swim bladder which led to a flattened tube that bifurcated around the vertebral column and exited via a small, oval-shaped hole in the pharyngo-cleithral membrane underneath each operculum. Identification of these distinctive holes revealed that venting had occurred on ascent in 96 % of in S. hippos captured from depth. Decompression from simulated 30 m water depth in an experimental hyperbaric chamber revealed that venting in P. georgianus commenced when predicted swim bladder volume was approximately double that of its initial volume and ceased when the fish were again near neutrally buoyant. A homologous structure was identified in S. lalandi and S. dumerili. This structure represents an important step in the evolution of the teleost swim bladder which circumvents the normal physoclistous restriction on rapid ascents by eliminating, or minimising, barotrauma. Ecological benefits of this ability include an improved ability to capture prey, escape predators and perform ‘spawning rushes’. The increased resilience to barotrauma provided by the swim bladder ‘vent’ may also reduce the levels of post-release discard mortality for deep-water species which possess the structure.

Using an effective combination of multivariate testing and ordination analyses, this study compares the extents to which the diets of two co-occurring fish species (Pagrus auratus and Pseudocaranx georgianus) are related to body size (length class), season and region and the rank order importance of those effects. Thus, volumetric dietary compositions were determined for these species on the lower west coast of Australia, where both are abundant, and for P. auratus from the mid west coast and P. georgianus from the south coast. The diet of P. auratus on the lower west coast was strongly related to body size and slightly less to season. With increasing body size, its diet shifted from predominantly ophiuroids to larger prey, such as brachyuran crabs, teleosts, echinoids and ultimately asteroids, probably reflecting a shift from foraging over soft sediments to areas over and around reefs. Seasonal changes on the lower west coast were restricted mainly to small P. auratus, while larger fish underwent seasonal changes further north. Analyses using a common size range of medium to larger P. auratus demonstrated that dietary composition differed more between regions than seasons. The relationships between diet and length class of P. georgianus on both the lower west and south coasts were less pronounced than for P. auratus and seasonal changes were restricted to the south coast, where amphipod consumption increased markedly in summer. The diet of P. georgianus was related far more to region than length class and season, with more small teleosts, small crabs, carideans and littorinids and less amphipods, isopods and small bivalves being ingested on the lower west than south coasts. Although crabs and teleosts were important typifying prey of P. auratus and P. georgianus, when co-occurring, the former predator tended to ingest greater volumes of larger and often less mobile prey. This reflects differences in dentition, jaw morphology and feeding behaviour and reduces the potential for competition for food resources. The results imply that P. auratus and P. georgianus are opportunistic feeders and that the effects of length class, season and region on dietary composition and their rank orders can vary markedly between species and for length class and season between regions for the same species.

Many studies that test for spatial patterns in fish assemblages do not have temporal replication, and where they do, the scale of this replication is in the order of seasons or years. Rarely are patterns tested at the scale of days or time of day. As a result, any descriptions of spatial patterns are potentially confounded by within or between day variations, with differences between locations possibly due to the differences between times sampled. This study aimed to determine whether significant short-term temporal variability existed within and between days in a temperate, shallow-water reef fish assemblage in south-western Australia. Three sites were sampled at morning, midday and afternoon for five consecutive days using baited remote underwater stereo–video systems. Significant differences were detected in the fish assemblage at different times of the day with morning and midday assemblages different from afternoon assemblages. Differences were detected between days with a significant shift in the assemblage after day two. The use of bait in this study was thought to influence the behaviour of Pseudocaranx spp. which furthermore influenced sampling of the entire fish assemblage between days. This study shows that large scale monitoring and sampling programmes using baited cameras need to consider the possible influence of within and between day variability in their experimental designs and must carefully design sampling to test for spatial and temporal structures in fish assemblages.

The primary structures of myoglobin (Mb) from the following five carangid species were determined: yellowtail Seriola quinqueradiata, greater amberjack Seriola dumerili, yellowtail kingfish Seriola lalandi, Japanese horse mackerel Trachurus japonicus, and silver trevally Pseudocaranx dentex. The sequences were of varying composition both in the coding and in the noncoding regions, but all contained the open reading frame of 444 nucleotides encoding 147 amino acids. Amino acid sequence identities of carangid Mbs were in the range of 81-99%. The similarity of the heme pocket and associated heme-binding residues of carangid Mbs were evidence of the conservative nature of Mbs. Similar to the other teleost Mbs, carangid Mbs did not contain a D helix and had mostly conserved A and E helices as well as E-F and G-H inter-helical segments. Hydropathy profiles of carangid Mbs showed species-specific variations where silver trevally Mb exhibited generally higher hydrophobicity. Phylogenetic analysis based on the primary structures was in agreement with conventional morphological taxonomy, establishing close proximity of carangid Mbs with those of cichlid and scombroid, the other members of the Perciformes order.

The larvae of two carangid fishes, silver trevally ( Pseudocaranx dentex ) and yellowtail scad ( Trachurus novaezelandiae ), were compared among coastal water masses and the East Australian Current (EAC). Samples followed a north to south gradient including a southern region of upwelling, generated as the EAC separated from the coast. Mean larval carangid densities were greater in the mixed layer (10-30 m) than the surface, but there was no difference between inshore and offshore stations or along latitudinal gradients. Overall, P. dentex recent larval growth over two days pre-capture was faster than T. novaezelandiae , and faster at inshore, coastal stations than in the EAC. Integrated larval growth rate (mm d −1 ) was usually faster at inshore stations for both species. T. novaezelandiae were enriched in both nitrogen (δ 15 N) and carbon (δ 13 C) stable isotopes relative to P. dentex . Larvae of both species captured within the upwelling region were enriched in δ 15 N and depleted in δ 13 C relative to other sites. Recent larval growth had a significant positive relationship with fluorescence (as a proxy of chlorophyll a biomass), and integrated larval growth rate had a significant positive relationship with fluorescence and larval isotope (δ 15 N) composition. Recent and integrated growth of larval T. novaezelandiae and P. dentex was enhanced by EAC separation and upwelling, and also in coastal water; stimulated by food availability, and potentially through exploitation of a different trophic niche.

Summary The objective of this study was to identify larvae species composition, distribution and abundance of carangids along the Brazilian coastal shelf area in order to provide background information on the reproductive community patterns. All carangid larvae used in this study are from the larval fish collection of the Zooplankton and Ichthyoplankton Integrated Laboratory of Federal University of Rio de Janeiro – Brazil (DZUFRJ). Carangid larvae were collected in 13 surveys (nine in the dry season and four during the rainy season) between 1998 and 2008, from Bahia (12°S) to Rio de Janeiro (23°S), comprising 158 sampling stations (45 coastal; 98 oceanic; 15 over seamounts). A bongo net with 330 and 500-μm mesh size was towed at a speed of about two knots, obliquely (surface-bottom-surface) from a maximum depth of 200 m. Samples were collected both during the day and at night and combined in the analysis. A total of 1321 carangid larvae were identified representing 14 species: Decapterus punctatus (56.7%), Chloroscombrus chrysurus (16.8%), Caranx crysos (8.4%), Selar crumenophthalmus (6.3%), Trachurus lathami (6.3%), Caranx latus (2.4%), Carangoides bartholomaei (1.3%), Oligoplites spp. (0.6%), Pseudocaranx dentex (0.3%), Seriola dumerili (0.2%), Elagatis bipinnulata (0.2%), Selene setapinnis (0.2%), Trachinotus carolinus (0.2%) and Selene vomer (0.1%). There was no significant difference in carangid density (P = 0.17) or in species composition (P = 0.09) among the coastal, oceanic and seamount stations. Although there was a significant difference in larval densities between the dry and rainy periods (P = 0.000264), the community composition did not vary significantly (P = 0.47). Therefore, seasonality (rainy and dry periods) seems to be the main factor affecting carangid densities although the community composition is not influenced by sampling periods or by the gradient coast-ocean.

The Goto station of the Japan Sea-Farming Association conducted marine ranching experiments with striped jack Pseudocaranx dentex from 1988 to 1999 in the Goto Islands, Nagasaki, Japan. Marine ranching is a stocking method where released fish are fed for some period after release in order to decrease initial mortality from starvation. Ranched fish were fed for 0, 90, and 15 days after stocking in 1997, 1998, and 1999, respectively. During the experiment, herons (grey heron Ardea cinerea, black-crowned night heron Nycticorax nycticorax, and great egret Egretta alba) were often observed preying on released fish in the ranching area. The present study estimated the number of fish preyed upon by herons during observation periods in 1997, 1998, and 1999 from the number of herons that flew into the ranching area and the predation rate on ranched fish by herons. The former was counted during sightings. The latter was estimated from the sighting observations and heron regurgitations. The number of herons that flew into the ranching area increased with the feeding period. The numbers of fish lost to predation by herons in 1997, 1998, and 1999 were estimated to be 0, 5,741, and 829, respectively.

This report describes Exophiala infection in cultured striped jack, Pseudocaranx dentex, in Japan in 2005. One hundred out of 35,000 fish died per day and mortalities continued for 1 month. Diseased fish showed swelling of the abdomen and kidney distension. Numerous septate hyphae, pale brown in colour, were seen in kidney in squash preparations. Histology revealed abundant fungal hyphae and conidia in gill, heart and kidney. Fungal hyphae were accompanied by cell necrosis and influx of inflammatory, mainly mononuclear cells. The fungus isolated from the diseased fish had septate hyphae, pale brown in colour and 1.8-3.0 microm in diameter. Conidiogenous cells were conspicuous annellides, short or cylindrical or fusiform in shape. Conidia were one-celled, ellipsoidal with smooth walls, accumulated in balls at the apices of annellides that tended to slide down, 1.5-2.0 microm in width and 3.0-5.0 microm in length. The fungus was classified into the genus Exophiala based on its morphology and as Exophiala xenobiotica based on the sequences of the ITS 1-5.8S-ITS 2 regions of rDNA. This is the first record of this fungus in a marine fish.

The fisheries benefits of marine reserves are hard to achieve for highly vagile fish species. An alternative is to protect essential habitats, such as spawning grounds, especially if these are stable over time. We studied the movements and habitat use patterns of white trevally Pseudo- caranx dentex (Carangidae), a commercially important species, to assist in the design of marine reserves. Diel, seasonal and inter-annual movements of trevally were studied using active acoustic tracking, passive acoustic monitoring and standard tag-release in the Faial Channel, Azores Islands. White trevally were captured at inshore and offshore reefs. Inshore trevally moved daily alongshore, using large activity spaces, while the short-term movements of offshore trevally were restricted to the reef summits. During the summer spawning season, both groups displayed frequent migrations of up to several kilometres, but inshore fish remained inshore, whereas offshore reef fish expanded their range to include visits to inshore sites. This behaviour eventually resulted in low long-term residence within the study area, especially that of inshore fish. During the spawning season, one inshore site was visited by most of the fish. However, instead of gathering in large aggregations at a single location, it appears that the trevally adopted a multiple-site visiting behaviour, which may increase mating opportunities through mixing between inshore and offshore fish that are otherwise segre- gated for most of the year. Protection of spawning biomass and sites for this species seems potentially feasible, but this would require protecting a suite of sites per island. Furthermore, because fish would not be fully protected under this scenario, we argue that such spatial management measures need to be accompanied by conventional fishing-effort control measures applied to all local populations.

Seven species of Pseudopecoeloides including five new are described from marine fishes in the waters off the coasts of Queensland, and West and South Australia. The new species are Pseudopecoeloides hickmani n. sp. from Pseudocaranx wrighti (Carangidae), P. lesteri n. sp. from Pseudocaranx dentex and Pseudocaranx wrighti, P. arripi n. sp. from Arripis georgianus (Arripidae), P. atherinomori n. sp. from Atherinonmorus ogilbyi (Atherinidae), P, hafeezullahi n. sp. from Trachurus novaezealandiae (Carangidae). Pseudopecoeloides scomberi Hafeezullah, 1971, which was transferred to Opecoeloides (Odhner, 1928) by Madhavi (1975) is reported from Scomberoides lysan (Carangidae) and returned to Pseudopecoeloides. Pseudopecoeloides tenuis Yamaguti, 1940 is reported from a new host species, Priacanthus macracanthus (Priacanthidae).

This study compared the histopathology of young striped jack Pseudocaranx dentex experimentally infected with the dematiaceous fungus Ochroconis humicola NJM 0472 with that of spontaneously infected fish. Moribund and freshly dead fish from both groups showed similar histopathology, and appeared to have been killed due to hyphae penetrating the visceral organs. Fish that survived the infection appeared to be able to suppress the fungal growth by well-established inflammatory reaction involving mycotic granulomas and granulation tissues. The results suggested that two types of O. humicola infection occur in young striped jack: an acute type infection, which is characterized by penetrating hyphae that cause direct tissue destruction and a chronic type infection, which is characterized by severe inflammatory reaction that causes functional disorders of the affected organs.

The current study was undertaken to enumerate Gram-positive bacteria in fresh sub-tropical marine fish and determine the effect of ambient storage (25°C) on the Gram-positive bacterial count. Total and Gram-positive bacteria were enumerated in the muscles, gills and gut of fresh and stored Pseudocaranx dentex, Pagrus auratus and Mugil cephalus on tryptone soya agar (TSA) and TSA with 0.25% phenylethyl alcohol (PEA), respectively. Initial studies indicated that PEA significantly reduced total aerobic bacterial count (TABC) whereas control Gram-positive bacteria were not affected by 0.25% PEA. TABC significantly increased in all fish body parts, whereas Gram-positive aerobic bacterial count (GABC) significantly increased only in the muscles and gills during ambient storage for 15 h. The TABC of the fish species increased from 4.00, 6.13 and 4.58 log cfu g−1, respectively in the muscles, gills, and gut to 6.31, 7.31 and 7.23 log cfu g−1 by the end of storage. GABC increased from 2.00, 3.52 and 2.20 log cfu g−1 to 4.70, 5.85 and 3.36 log cfu g−1. Within each species, TABC were significantly higher in the gills compared to that of muscles and gut; however, no significant differences were found in GABC between muscles and gills. This study demonstrated the potential importance of Gram-positive bacteria in sub-tropical marine fish and their spoilage.

Silver trevally ( Pseudocaranx dentex ) are highly athletic marine teleosts inhabiting the tropical waters of the Great Barrier Reef, Australia. Burst swimming increased plasma lactate from 1.6 ± 0.4 S.D. to 21.6 ± 3.3 mM ( N = 6), among the highest values reported for functional hypoxia in fish. These data support the hypothesis that elite swimmers release lactate produced in the myotome into the circulation following anaerobic burst activity. The fish further developed a hyperglycaemic response to burst exercise with plasma glucose increasing from 6.6 ± 2.0 to 13.2 ± 2.3 mM ( N = 6). Post-exercise erythrocyte swelling also occurred, but nucleoside triphosphate levels remained unaltered and do not provide a mechanism to modulate haemoglobin function during exercise. Metabolism of the blood cells appeared to be fuelled by both lactate and glucose.

Smith-Vaniz W.F. and Jelks H.L. 2006. Australian trevallies of the genus Pseudocaranx (Teleostei: Carangidae), with description of a new species from Western Australia. Memoirs of Museum Victoria 63(1): 97–106. Pseudocaranx dinjerra sp. nov. is described from Western Australia. It differs from the Australian endemic Pseudocaranx wrighti in having the posterior margin of the upper jaw nearly vertical, lachrymal without scales, 19–21 versus 24–28 lower gill rakers and 53–66 versus 37–48 scales in the curved part of the lateral line. The new species is distinguished from Australian populations of P. georgianus and “dentex” primarily by having a different combination of meristic values including 14 versus 15 caudal vertebra, 19–21 versus 21–24 segmented anal-fi n rays and 58–75 versus 72–95 total lateral-line scales. Diagnoses are given for P. wrighti and P. georgianus, and specimens from Queensland and Lord Howe Island are discussed and provisionally identifi ed as P. dentex.

Marine ranching of striped jack Pseudocaranx dentex was undertaken at the Goto Station of the Japan Sea-Farming Association between 1988 and 1999. This stocking method aimed at protecting the released fish from predators and preventing dispersion by feeding for a certain period. The present study examined the reduction process in the number of ranched striped jack and the conditions required to keep the fish in the ranched area. We estimated the sighting rate and the dispersion coefficient from the ranched area per day from 1993 to 1999, on the assumption that natural mortality can be ignored, using the observed number of fish from the sighting observation. The number of fish that remained was represented by a decreasing exponential function of day. This decreasing process was divided into six phases at most. We found two phases when the number of fish that remained markedly decreased in 1993 and 1995. In the first phase, the dispersion was caused by lack of food due to an increased food demand caused by the growth of fish. In the second phase, the ranched fish moved out from the ranched area due to the cessation of feeding. This dispersion was also observed in other years when feeding was stopped.

In 1999, disease outbreaks in juvenile Atlantic cod Gadus morhua that showed the classic signs of viral encephalopathy and retinopathy (VER) were reported in Nova Scotia. Brain and retinal tissues from moribund cod showed diffuse degenerative vacuolative encephalopathy and degenerative histiocytic retinitis. The affected brain and retinal tissues were observed to be positive for nodaviral antigens by means of immunohistochemical techniques. We partially characterized a nodavirus-like agent from brain and eye tissues and cell culture using reverse-transcriptase polymerase chain reaction and primer sets originally designed for amplification of white trevally Caranx dentex (also known as striped jack Pseudocaranx dentex) and Atlantic halibut Hippoglossus hippoglossus nervous necrosis virus coat (capsid) proteins. Sequencing of the T2 region of the coat protein revealed high similarities (>85% nucleotide identity) to the coat protein genes of other fish nodavirus strains, especially those of Atlantic...

□ Pseudocaranx dentex (Bloch & Schneider, 1801) – White trevally; Xareu-bicudo or Xaréu ②, Encharéu ②③, Charéu ③, Published as part of Carneiro, Miguel, Martins, Rogélia, Landi, Monica & Costa, Filipe O., 2014, Updated checklist of marine fishes (Chordata: Craniata) from Portugal and the proposed extension of the Portuguese continental shelf, pp. 1-73 in European Journal of Taxonomy 73 on page 51, DOI: 10.5852/ejt.2014.73, http://zenodo.org/record/3866515

This study was conducted to investigate the effect of squid meal and astaxanthin in dry pellets on the spawning performance of striped jack. Two groups of 8-year-old fish with an average bodyweight of 3.5 ± 0.4 kg were used. The control group was fed a raw fish mix (RF) and the exper- imental group was fed steam dry pellets (as-DP) containing 10 p.p.m. astaxanthin and squid meal, the latter replacing half the fish meal. Each group was fed once a day, three times a week in float- ing net cages for a period of 5 months. Seven females and seven males were selected from each group and transferred to 65 m 3 indoor concrete tanks for spawning, where they were kept at optimum spawning conditions (22∞C) for 1 month. The average bodyweights of selected fish were 3.8 ± 0.5 kg and 3.8 ± 0.6 kg for the RF and as-DP groups, respectively. Both groups spawned a total of 18 times and the mean total egg production and egg quality, measured in terms of buoyancy, fertilization and hatching rates, showed no significant differences (P > 0.05) between groups. Total larval production was 679.9 ¥ 10 3 and 678.1 ¥ 10 3 larvae/kg-female for the RF and as-DP groups, respectively. These results show that the combination of astaxanthin and squid meal in dry pellets for striped jack brood- stock improved the overall spawning performance to a level similar to that of fish fed on RF.

SUMMARY: This study was carried out to investigate the effects of dietary squid meal or a combination of squid meal and krill meal as part of the protein source in dry pellets on the spawning of striped jack Pseudocaranx dentex. Five months prior to spawning, 7-year-old fish were divided into three groups of 10 fish each (male : female ratio, 5 : 5). The control group was fed a raw fish mix (RF) and the other two groups were fed either steam-dry pellets with squid meal replacing 50% of their fish meal (fs-DP) or steam-dry pellets containing equal proportions of fish, squid and krill meals (fsk-DP). Feeding was carried out once every other day in 5 × 5 × 5 m floating net cages and the fish were transferred to 65 m3 indoor tanks for spawning. Eggs and yolksac larvae produced were evaluated for their quality and those obtained during the first 2 weeks of spawning were sampled for chemical analysis. The fish had an average bodyweight of 3.5 ± 0.4 kg at spawning. Although egg production of the RF group was significantly higher (P < 0.05) than that of the dry pellet groups, the fs-DP group produced the best quality eggs with higher fertilization and hatching rates. The fsk-DP group had the lowest egg production and quality. Lipid classes and fatty acid compositions of eggs and yolksac larvae were dependent on the broodstock diets. These results show that the combination of fish meal and squid meal in dry pellets for striped jack improved egg quality but not production whereas the combination of fish meal, squid meal and krill meal was not effective.

SUMMARY: This experiment was conducted to investigate the effect of astaxanthin supplemented steam-dry pellets on the spawning of striped jack Pseudocaranx dentex. Five months before spawning, 7-year-old fish were divided into three groups, each consisting of five females and five males. The control group was fed a raw fish mix (RF) and the test diets consisted of steam-dry pellets (DP) and steam-dry pellets supplemented with 10 p.p.m. astaxanthin (a-DP). Feeding was carried out once per day, three times a week in floating net cages. The RF and the a-DP groups produced more than three times the amount of eggs produced by the DP group. The buoyancy, fertilization, and hatching rates were higher and similar for the RF and the DP groups. Total lipid contents of the diets, eggs, and larvae were similar among the groups. Highly unsaturated fatty acids (n-3 HUFA) and polar and non-polar lipids in eggs and larvae were also related to their dietary availability. These results indicate that astaxanthin, due to its various physiological functions, improved the condition of the broodstock and enhanced total egg production but not egg quality as striped jack do not incorporate carotenoids into their eggs. Therefore we confirm that the nutritional quality of diets given to striped jack prior to spawning plays a fundamental role in egg production, quality and egg composition.

The marine ranching of striped jack (Pseudocaranx dentex) in Japan is a new type of fishery enhancement that releases cultured juveniles and keeps them in coastal waters without cages, utilizing their behaviour of associating with floating objects. To improve the release strategies, the behaviour of released fish under different conditions was observed directly using SCUBA. We found that factors of fish size, the amount of handling stress and trained feeding behaviour had an impact on the potential loss of the juveniles from the release site. Large juveniles (115 mm) showed a greater potential for loss from the release site than smaller juveniles (59 mm) due to diving deeper immediately after release (an average of 5.4 vs. 4.1 m, respectively). Stressed fish dived deeper than fish provided with a vertical underwater structure (average of 8.5 vs. 3.8 m, respectively). Fish trained to respond to sound for feeding dived to a more shallower depth (3.3 m) and stayed near the release site. Handling stress before release may be the main cause of the loss of fish from the release site, while training showed great potential for improving fish retention at the release site.

Silver trevally (Pseudocaranx dentex), also known as striped jack or shimaaji, is farmed intensively in Japan (Watanabe et al., 1990) where it can reach 1 kg after 2 years (T. Takeuchi, pers. comm.). Growth rates in Australasian waters are unknown, although data from New Zealand fisheries suggest that juveniles are moderate to fast growing in the wild (Stewart and Grieve, 1993). This study was conducted to obtain information about the influences of temperature on feed intake and to assess growth performance in order to evaluate the aquaculture potential of silver trevally at the southern limit of their distribution in Australia. Juvenile silver trevally caught using a beach seine between April and June 1995 at Stieglitz Beach, Tasmania (142°19'E; 41°20'S) were maintained at the Taroona Marine Research Laboratories. Prior to the experiment described here the fish had been used in a feed experiment for 12 weeks. Diet did not have a significant effect on growth (Gardner, 1998) and the fish were fed commercial feed for 3 weeks before the present experiment. Ration was 2% BW/day over the 15 weeks. Seventy-four fish of mean [SE] weight (37.0 [12.3] g) were randomly allocated to each of three 4 m tanks supplied continuously with unfiltered seawater. Fish were maintained indoors at ambient temperature (16.7 °C decreasing to 12.8 °C) and salinity (31–34‰) under a L8:D16 photoperiod for 112 days (23 January to 14 May 1996). A commercial salmon feed (Gibson’s Ltd, Tasmania: 52.0 (0.01) % crude protein; 13.0 (0.12) % crude fat; 11.8 (0.07) % ash; 21.0 kJ/g GE) was fed to satiation by hand four times per day and total feed intake (g) recorded daily. Wet weight (W, g) and fork length (L, cm) were measured at the start and after 56 and 112 days. Fulton’s condition factor (K) was calculated as 100 3 (W/L). Specific growth rate was calculated for wet weight (SGRW) and fork length (SGRL) as SGR (%/day) 5 100 3 [(ln X2/ln X1)/t]

Suspension feeding is known in 16 fish families, with one instance of ram filtering recently recorded in a piscivorous naucratine carangid. I present field evidence of suspension feeding by Pseudocaranx dentex, a piscivorous and macroinvertivorous carangine jack, and note that ram filtering is already recorded for the leatherjacket Oligoplites saliens, a piscivorous and scale-eating scomberoidine carangid. Based on food habits and postulated phylogenetic relationships, I suggest that additional species of carangine jacks ram filter and that suspension feeding is a derived condition within the Carangidae.

Two new genera and four new species of monorchiid digeneans are described from the Great Barrier Reef and Moreton Bay, Queensland. Provitellus turrum n. g., n. sp. from Pseudocaranx dentex and Trachinotus coppingeri is characterised by the presence of vitelline follicles in the forebody, a single testis, a unipartite terminal organ and filamented eggs. Ovipusillus mayu n. g., n. sp. from Gnathanodon speciosus is characterised by the presence of two testes, vitelline follicles overlapping the ventral sucker and a large, complex cirrus-sac that contains a coiled eversible ejaculatory duct joined by the pars prostatica halfway along its length. Paramonorcheides pseudocaranxi n. sp. from Pseudocaranx dentex differs from other species described in this genus in the longer flatter forebody, entire ovary and the well-developed cirrus-sac. Chrisomon gaigai n. sp. from Trachinotus coppingeri and T botla is characterised by the unflattened forebody and transversely oval pharynx. Chrisomon is redefined to include species of Lasiotocus with a vitellarium composed of clusters of tubular acini, creating the following new combinations: C. albulae n. comb. for L. albulae Overstreet, 1969, C. ulua n. comb, for L. ulua Yamaguti, 1970 and C. weke n. comb, for L. weke Yamaguti, 1970. The diagnosis of Lasiotocus is amended accordingly and the new combinations, L. polynemi n. comb. and L. sunderbanensis n. comb., are created for C.polynemi Dutta, Hafeezullah & Manna, 1994 and C. sunderbanensis Dutta, Hafeezullah B Manna, 1994, respectively. Extrapolation of our collection data suggests that there may be as many as 80 species of monorchiids infecting carangid fishes in Australia and 180 species infecting carangids in all oceans of the world. The latter figure greatly exceeds the number of monorchiids described from all host families to date.

Animals in social environments can enhance their learning efficiency by observing the behaviour of others. Our previous study showed that learning efficiency of schooling fish increased through the observation of the behaviour of trained demonstrator conspecifics. The present study aimed to verify the key factor of observational learning by investigating what information is important for social transmission of feeding information. A striped jack (Pseudocaranx dentex) observer was provided with one of the five observation treatments: (a) pellets observation, where pellets were dropped near the aeration in an adjacent tank; (b) responding conspecific observation, where a trained conspecific demonstrator responded to the aeration without food in the adjacent tank; (c) foraging conspecific observation, where a conspecific demonstrator foraged near the aeration in the adjacent tank; (d) nearby pellets observation, where pellets were dropped in a transparent column near the aeration in the observer tank; and (e) foraging heterospecific observation, where a filefish (Stephanolepis cirrhifer) demonstrator foraged near the aeration in the adjacent tank. The response to the aeration in these observers was compared with that of controls who did not observe any behaviour. Only individuals who observed foraging conspecifics showed a response to the aeration after observing. These results suggest that observer fish acquire feeding information not through recognition of prey items or through imitation of the demonstrator, but through the vicarious reinforcement of a conspecific for foraging.

The development of sensory and swimming organs in striped jack Pseudocaranx dentex was morphologically and histologically analysed and compared with the development of phototaxis and rheotaxis. A major inflection of allometric growth occurred at 9 mm TL and a minor inflection occurred at 20 mm. At about 10 mm, fin ray formation was complete. Red muscle layers first appeared at 4.3 mm and increased to more than 10 layers at 12 mm. These morphological changes were considered to be essential for cruise swimming, which might help higher behaviours such as predator evasion, schooling and migration. Strong phototaxis showing a preference for a light intensity of 105 lux appeared at 3.5 mm (3 days old), corresponding with the development of pigment in the retina. The light intensity preference changed from 10 to 10 lux at 10–12 mm (23–25 days), when the rod formation was suggested. Rheotactic behaviour was apparent in 4.5 mm larvae. Canals of buccal lateral lines were formed from 8–18 mm, while those of trunk la...

Behaviors of the striped jack Pseudocaranx dentex to the shade of flotsam were observed in experimental tanks to determine whether or not the shade would act as a factor to trigger association behavior of fishes to a flotsam.During the daytime, 20 fish of 23cm TL preferred to distribute under the cover which was set on the right half side of a 90m3 outdoor tank, while there was no difference in fish distribution between the right and left sides in a control tank without cover. During the nighttime, however, there was no difference in horizontal distribution between the test and the control tanks. Fish in the test tank tended to distribute at shallower depths than those in the control tank during the daytime, while both fish distributed at the surface during almost all of the nighttime. When the light intensity was increased by more than 10, 000 lx in an outdoor 60m3 tank with a 90×180cm plywood board at the surface, 21 striped jack of 24cm TL distributed in the shade of the plywood board, while they went out of the shade and swam around the tank when the decrease in light intensity exceeded 10, 000 lx. These data suggested that the shade might attract the striped jack and trigger the association behavior. It was also suggested that in marine ranching of the striped jack in coastal waters the feeding station should provide fish with shade to enhance their association behavior and to keep fish at a fixed area in the sea.

Two sympatric morphs (type A with a vertebral number of 25 and type B with a vertebral number of 24) of striped jack Pseudocaranx dentex (Bloch & Schneider) were analysed genetically. A part of the 16S–rRNA region of mtDNA was amplified with polymerase chain reaction for 24 specimens, and a restriction enzyme fragment polymorphism showed significant differences between the two types. While all specimens sampled in Ogasawara were identified as type B, about 90% of striped jack in Oita were type A and 10% were type B. Although the spawning areas of these two types are still unknown, significant genetic differences between the two sympatric morphs show that recruitment and migration patterns might differ from each other. The current system suggests the possibility that the juveniles of type B in Oita may migrate from the Ogasawara Islands.

This study characterized anisakid nematodes in estuarine and near-shore species of fish in southern Western Australia. A total of 108 fish representing 13 species were examined for anisakid larvae. For the molecular characterization of anisakid larvae (n=218), we used PCR-coupled mutation scanning-sequencing-phylogenetic analyses of sequence variation in the internal transcribed spacers of nuclear ribosomal DNA. With the exception of Sillaginoides punctatus and Sillago schomburgkii, all the fish species examined (Aldrichetta forsteri, Arripis georgianus, Hyporhamphus regularis, Mugil cephalus, Platycephalus speculator, Pomatomus saltatrix, Pseudocaranx dentex, Pseudocaranx wrighti, Thysanophrys cirronatus, Trachurus novaezeelandiae and Upeneichthys lineatus) harboured at least one species of anisakid. Mutation scanning analysis identified 11 different genotypes of anisakid larvae. Phylogenetic analyses of the sequence data, employing reference sequence data for a wide range of anisakids (31 species) from public databases, revealed the presence of Anisakis pegreffii (n=3), Contracaecum multipapillatum (49), Contracaecum ogmorhini (1), Hysterothylacium larval type IV (82), Hysterothylacium larval type Vb (14), Hysterothylacium larval type VIII (3), Hysterothylacium larval type X (65), and Terranova type I (1) in the fish examined. The present study provides valuable information on the diversity of anisakids in southern Western Australia and also a basis for future investigations to assess the public health significance of these parasites.