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The northern edge of Georges Bank is an important seasonal foraging habitat for swordfish (Xiphias gladius) in the North Atlantic, where aggregations support commercial pelagic longline and harpoon fisheries. Following a period of overfishing during the 1990s, the North Atlantic X. gladius stock underwent a period of recovery during the early 2000s and was considered rebuilt in 2009. We analysed stomach contents from X. gladius (n = 39) harvested by the Canadian harpoon fishery on Georges Bank in 2007 to characterize diet in this important foraging habitat. We used electronic tagging data from X. gladius (n = 6) on Georges Bank in 2005–2007 to assess vertical habitat preferences and associated prey composition within those zones. We also used stable isotope analysis (δ13C and δ15N) of X. gladius liver (n = 2) and common prey types (Paralepididae, Myctophidae, Merluccidae, Ommastrephidae) as a longer‐term record of feeding. Stomach contents were co‐dominated by Paralepididae [31.9% weight (W)] and Ommastrephidae (36.8%W) with secondary contributions from hake (Merluccidae, 6.5%W), Myctophidae (2.9%W) and Sebastidae (2.1%W). X. gladius displayed diel vertical migrations, descending to depths of 300–400 m during daytime followed by residence in surface waters at night. X. gladius liver δ15N values were similar to or lower than values of primary stomach contents, likely due to bias of diet consumed in southerly waters with lower nitrogen isotope baselines prior to arrival on Georges Bank. Diet data are similar to results from historical studies from the late 1950s to the early 1980s. This apparent temporal stability to the underlying food web in this region may explain the high X. gladius site fidelity observed in electronic tagging studies and the consistent aggregation of these fish to this region. [ABSTRACT FROM AUTHOR]

Two unusual adult specimens of the barracudina Arctozenus risso were caught in midwater trawls off the Flemish Cap in April 2016. These specimens displayed atypical traits including lack of teeth and gill rakers and fragile jaw bones; a combination of morphological examination and mtDNA sequencing confirmed species identification. Both specimens exhibited ripening ovaries and testes, confirming simultaneous hermaphroditism. These fish represent the first records of late‐stage loss of features in the genus Arctozenus and may indicate a relationship to spawning in larger specimens. [ABSTRACT FROM AUTHOR]

The goal of this research was to evaluate the optimal geometry of a pressurized paralepipedic fuel tank with the finite element analysis (FEA). Geometrical modeling was done in the AutoCAD Autodesk 2017 software and its stress-strain state calculation was done using the SolidWorks 2017 software for both thermal and mechanical events. In numerical analysis, polynomial interpolation was applied to determine variation laws of the von Mises stress and linear deformation distribution. The relationship between properties and loading conditions can be utilized to optimize the fabrication process to obtain high quality products. The computational analysis results revealed that the pressurized paralepipedic fuel tank satisfies the design regulations and can be applicable for use in automotive industry. [ABSTRACT FROM AUTHOR]

The shallow water barracudina †Holosteus esocinus Agassiz, 1835, from the Eocene of Monte Bolca, Italy, is redescribed in detail. This paralepidid taxon exhibits a unique combination of features, including the following: articular–quadrate joint located below the posterior margin of the orbit; eight branchiostegal rays; small recurved teeth on premaxilla; large, thin and pointed teeth on palate and lower jaw without corrugate pattern or serrate margin; about 19-22 anal–fin rays; about 10-12 pelvic–fin rays; five or six autogenous hypurals; proximal ends of the epaxial caudal–fin rays that extensively overlap the associated hypurals; bony fulcral scales just in front of the dorsal and ventral caudal–fin lobes; and body completely naked, with a broad, uniform, mid-dorsal brown-pigmented band along the back. †Holosteus esocinus shares a number of features with the Oligocene †Pavlovichthys mariae, and together they constitute the extinct subfamily †Holosteinae, which is redefined herein. A phylogenetic analysis of aulopiform genera using 140 morphological traits supports the monophyletic status of the holosteines as crown group Paralepididae. The peculiar morphology of holosteines resembles in many aspects the body plan of certain modern and extinct ambush predators, suggesting that the morphological adaptations of these Palaeogene fishes can be related, at least in part, to a predatory strategy experimented with by paralepidid fishes uniquely in the context of the massive adaptive radiation of teleost fishes in the aftermath of the end-Cretaceous extinction. [ABSTRACT FROM AUTHOR]

Records of 9 barracudinas Sudis hyalina Rafinesque, 1810 off the Syrian coast are reported in this note, constituting the first records in the area and confirming the eastern extension range of the species in the Mediterranean. The occurrence of the species is commented and discussed, in the region where a sustainable population is probably established. [ABSTRACT FROM AUTHOR]

In order to assess feeding habits and trophic level of this species, we analysed the stomach content of 189 specimens collected monthly in the southern Tyrrhenian Sea (central Mediterranean Sea). The results showed that this species is a pelagic predator focusing on paralepidid fish and, more in detail, on two species such as Paralepis speciosa and Paralepis coregonoides. Among cephalopods, Heteroteuthis dispar was the most abundant prey item in the stomach contents, whereas among crustaceans the hyperidean amphipods Phrosina semilunata and Brachyscelus crusculum were the most representative species. In the present study, the diet of the albacore did not vary significantly throughout the period of study focusing, in the different season of catch, on the same prey species. Not even a size-related diet shift was observed, with a partitioning of the albacore sample into five size groups. Levin’s standardized index showed a low value indicating a limited trophic niche width, with a diet dominated by a limited number of taxa and then a specialist behaviour for this predator. The estimated TROPH value for T. alalunga resulted very similar to that calculated in Mediterranean Sea for other species as well as Xiphias gladius, Thunnus thynnus, Euthynnus alletteratus and Sarda sarda. Then, the albacore tuna can be considered as a top carnivore. [ABSTRACT FROM AUTHOR]

Three barracudina fishes (Paralepididae) were newly recorded from the southern sea of Korea. Lestidium prolixum is characterized by a single band of luminous ducts on the midventral line and absence of a papilla anterior to the eye. Lestrolepis intermedia and L. japonica are similar in having a black papilla immediately in front of the eye and two bands of luminous ducts on the midventral line. However, the dorsal fin of L. intermedia is located more posterior along the body than that of L. japonica, and L. intermedia have larger number of anal fin rays 42 (vs. 36–40) and vertebrae 95 (vs. 86–87) than L. japonica. [ABSTRACT FROM AUTHOR]

Abstract??The early life stages ofLestidiops sphyraenopsis(Paralepididae) are described on the basis of 14 specimens [7.8?mm in notochord length (NL)?88.6?mm in standard length (SL)] collected from the western North Pacific, and the holotype ofStemonosudis molestais reexamined. LarvalL. sphyraenopsisoccurred in the Kuroshio waters, and juveniles were taken in the Kuroshio?Oyashio transition waters. Diagnostic characters of larval and juvenileL. sphyraenopsisare 96?101 myomeres; 27?31 anal fin rays; 4?9 peritoneal pigment sections in larvae (7.8?mm?NL?27.3?mm?SL); dorsal and anal pigment patches present; and anus located anterior to a vertical through dorsal fin origin.Stemonosudis molesta, known only from the holotype from the South Pacific, is similar to immature specimens ofL. sphyraenopsis, but can be clearly distinguished from the latter by having higher vertebral counts (105 vs. 96?101) and by morphometric and pigment differences. Consequently,S. molestais a valid species, and the distribution ofL. sphyraenopsisis restricted to the North Pacific. [ABSTRACT FROM AUTHOR]

Six specimens (2 flexion larvae: 9.5–10.4?mm in notochord length; 4 postflexion larvae: 12.3–18.2?mm in standard length) collected from the western North Pacific are tentatively ascribed to the genus Uncisudis of the tribe Lestidiini of the subfamily Paralepidinae (Paralepididae) in sharing remarkably elongate and filamentous pelvic fin rays, their tips reaching the origin of the anal fin. They are described as Uncisudis posteropelvis sp. nov. in uniquely having the insertion of pelvic fins closer to the origin of anal fin than to the posterior end of dorsal fin base among lestidiine species. Addition to this character, the new species has remarkably elongate and filamentous dorsal fin rays, the short distance between anus and origin of anal fin (4.2–6.1% of standard length, SL), the posteriorly located pelvic fins (prepelvic length 69.4–71.5% SL), dorsal fin rays 10, anal fin rays 28–29, myomeres 41–42?+?38–40?=?80–81 (vertebrae 38?+?41?=?79), and peritoneal pigment spots 11–12. The occurrence of larvae differing in pigment pattern from the present new species suggests another undescribed species of Uncisudis in the western South Pacific. [ABSTRACT FROM AUTHOR]

abstract age and growth of a paralepidid, lestrolepis japonica, were determined from sagittal otoliths of specimens collected from april 2001 to february 2002 in kagoshima bay, southern japan. marginal growth increments indicated that the annulus was formed once a year, in august and september. four groups were recognized, having none, one, two, or three annuli, respectively. age in months was assigned to each individual on the basis of august as the birth month. the maximum recorded age was 48 months. growth was expressed by von bertalanffy's equation, lt = 171.91{1 - exp[-0.148(t + 0.403)]}, t being the age in months and lt the standard length (mm) at age t. [ABSTRACT FROM AUTHOR]

During Italian expeditions, ichthyoplankton was collected in the Ross Sea and Terra Nova Bay, by BIONESS and Hamburg Plankton Net (250-µm and 500-µm mesh, respectively). A total of 394,453 fish larvae representing 46 species, 27 genera and 9 families were collected. Pleuragramma antarcticum dominated during three of the four cruises, whilst in 1994/1995 Trematomus lepidorhinus was also abundant. The most abundant icefish was Chionodraco myersi, which co-occurred with P. antarcticum. Macrouridae, Myctophidae and Bathylagidae were oceanic. Paralepididae occurred in all areas. Notothenioids, nearly 100% of the catch, occurred close to the coast and dominated the shelf ichthyoplankton community. [ABSTRACT FROM AUTHOR]