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Three sardine species of Harengula and one of Opisthonema (Clupeiformes, Clupeidae) are known in the Western Atlantic, where the Amazon-Orinoco plume has been recognized as a major biogeographic barrier, albeit permeable to larger and generalist species. Here we used mitochondrial cox1 gene DNA sequences to check the lineage delimitation of both genera, testing the influence of the Amazon-Orinoco barrier (AOB) and marine provinces on their phylogeographic structure. Results indicate that the two genera are differently affected by the AOB, including cryptic speciation in Harengula and population structure in Opisthonema. Harengula show a broad distribution in the Brazilian Province (BRA) distinct from H. clupeola and H. jaguana from the Greater Caribbean Region (GCR). Divergence time between Harengula from the GCR vs. BRA was estimated as about 2.4 Mya, which coincides with the period of increasing sediment and freshwater discharge of the Amazon River in the Atlantic. Results also indicate the existence of a single species of Opisthonema, albeit with population structuring related to the marine provinces. Since species of both genera are relevant to artisanal fisheries and the maintenance of oceanic ecosystems, these results may help in fisheries management of these important marine resources. [ABSTRACT FROM AUTHOR]

The present paper is a review of the available literature on the significance of forage fish, the plethora of services they provide, and the threats faced by them. Forage fish are pelagic planktivorous species that operate as conduits of energy between the lower trophic level (plankton) and the upper trophic level (predators). A variety of ecosystem services are provided by them, from serving as prey for higher trophic levels to producing fish meal and oil. Forage fish have a consumption value for humans and cultural importance to many societies. Forage fish have faced constant natural and anthropogenic threats in the past, resulting in numerous fish collapses which subsequently impacted their predators. The economic benefit provided by forage fish has been estimated to be approximately $ 18.7 billion per annum. An introspection of the data on ecosystem services revealed lack of data on regulating and cultural services, eventually leading to a monetary underestimation and their commercial prioritization over the wider benefits they provide. [ABSTRACT FROM AUTHOR]

Understanding environmental features that impact population structure in marine systems is fundamental for sustainable fisheries management. In sardines and herrings, temperature is usually indicated as an important attribute in recruitment. Here, we investigate the hypothesis of additional structuring along the Brazilian coast in the scaled sardine Harengula sp. and possibility of using the highly variable mitochondrial control region as a molecular marker along continuous studies. We sequenced the mitochondrial control region of 152 individuals of Harengula sp. from 10 locations along the Brazilian coast and the archipelagoes of Fernando de Noronha (FNO, oceanic) and Abrolhos (ABR, continental) in the western South Atlantic. Analyses of molecular variance and haplotype network indicate that Harengula sp. is structured in three populations: one in FNO, isolated from the mainland by depth; and two in the Brazilian coast, mainly separated by temperature. Considering that FNO is a marine protected area and that sardines from this archipelago form a stock separated from the coast, their fisheries should be managed separately by participative cooperation among environmental agencies and local community. Additionally, it indicates that the mtDNA control region can be used in a long-term phylogeographic study of Harengula sp. as samples from other localities are obtained. [ABSTRACT FROM AUTHOR]

Tenualosa ilisha is a popular anadromous and significant trans-boundary fish. For sustainable management and conservation of this fish, drawing an appropriate picture reflecting population status of this species is very essential based on their all-strategic habitats in Bangladesh. In this study, 139 samples from 18 sites were collected and cross-species gene enrichment method was applied. Like most of the Clupeiforms, nucleotide diversity of this shad was very low (0.001245–0.006612). Population differences between most of the locations were low and not significant (P > 0.05). However, P values of a few locations were significant (P < 0.05) but their pairwise FST values were very poor (0.0042–0.0993), which is inadequate to recognize any local populations. Our study revealed that the presence of a single population in the Bangladesh waters with some admixtured individuals, which may contain partial genes from other populations. Most of the individuals were admixed without showing any precise grouping in the ML IQtree and Network, which might due to their highly migratory nature. Fishes from haors and small coastal rivers were not unique and no genetic differences between migratory cohorts. The hilsa shad fishery should be managed considering it as a single panmictic population in Bangladesh with low genetic diversity. [ABSTRACT FROM AUTHOR]

The anchoveta (Engraulis ringens) and sardine (Strangomera bentincki) are coastal pelagic species with important spawning areas off the coast of Chile. The discharge of secondary-treated effluents from a kraft pulp plant near one of these spawning areas has raised environmental concerns. Therefore, effluent effects on the development of anchoveta and sardine eggs were assessed by in vitro exposure. Eggs were sampled between 2007 and 2010 off Talcahuano, Chile. Subsequent toxicity tests (96 h duration, 12 °C) were performed using increasing effluent concentrations, a filtered seawater control, and two potassium dichromate concentrations (to verify consistent embryonic sensitivity). Egg mortality and hatching success were evaluated. For anchoveta, mortality (9.9 ± 7.1%) did not significantly differ among groups in five toxicity tests except the final toxicity test that showed significant differences in mortality (5.6% control vs 27.8% in 100% effluent). For sardines, no differences in mortality existed between the effluent dilutions (2.6 ± 3.6%) and control (6.3 ± 3.9%). Notably, anchoveta egg survival and hatching success rates were inconsistent, i.e., the highest rates of hatching failure occurred on the same sampling date with the highest rates of survival for the 100% effluent group (72%). In conclusion, the obtained results indicate that (i) anchoveta egg mortality and hatching failure increase only under 100% effluent exposure, coinciding with decreased egg quality near the end of spawning season and (ii) high effluent dilutions not significantly increase sardine and anchoveta egg mortalities. Nevertheless, the recorded adverse effects to the hatching process should be studied in greater detail, particularly considering interspecific variability and the complexity of reproductive processes, especially during early development. [ABSTRACT FROM AUTHOR]

Stolephorus continentalis sp. nov. is described from 36 specimens from Hong Kong and northern Vietnam. The new species is closely related to the endemic Chinese anchovy S. chinensis (Günther 1880), which is redescribed with a lectotype designated, with both species having a long upper jaw with the posterior tip just reaching to the posterior border of the preopercle; no predorsal scute; the posterior preopercular border rounded, convex; the posterior tip of the depressed pelvic fin not reaching to vertical through dorsal-fin origin; a pair of dark patches behind the occiput without a following pair of dark lines; and no black spots below the eye and lower-jaw tip. However, the new species is distinguished from S. chinensis in having higher total gill-raker counts on the first, second, third, and fourth gill arches (43-48, 33-40, 23-26, and 18-21, respectively vs. 35-41, 29-34, 19-24, and 16-19), and longer pectoral (16.5-19.2 % SL vs. 15.8-16.4 %) and pelvic fins (9.1-11.6 % SL vs. 8.2-8.3 %). Examination of the specimens previously considered as S. chinensis from Southeast Asia revealed that they differed from true S. chinensis and S. continentalis in having eight transverse scales (vs. 10 in the latter two species). The applicable scientific name for the Southeast Asian species is suggested here as Stolephorus oceanicus Hardenberg 1933. [ABSTRACT FROM AUTHOR]

The river plate sprat Platanichthys platana (Regan, 1917) is a small clupeid fish of South American fresh and brackish waters which was introduced outside of its native range, becoming widespread in the Billings Complex, a highly eutrophic urban reservoir located in the metropolitan area of São Paulo city, Upper Tietê River Basin (São Paulo State, Brazil). To better understand some aspects related to the invasion of this species in the reservoir, we assessed its diet through the analysis of stomach contents, niche breadth and feeding selectivity. Simultaneously to fish catches, zooplankton samples were collected at three reservoir arms with different anthropic influences during the dry and rainy seasons of 2014. Zooplankton diversity and dominance varied between sites, while composition at the genus level was similar. Sprat fed predominantly on zooplankton (68.3%), consuming a broad diversity of prey ( Bosmina, Lecane , Chydoridae, Cyclopoida and Harpacticoida copepods), which were selectively predated. Consumed species varied according to site, season and fish size, with Cladocera being dominant at the most eutrophic site (Bororé). Considering spatial differences in the consumed zooplankton, the analysis of percentage similarity (SIMPER) indicated the highest dissimilarity (95.3%) between the Bororé (hypereutrophic) and Grande River Reservoir (supereutrophic) sites, while trophic niche width increased from the most impacted (Bororé) to the most preserved site (Capivari). The high captures of the sprat in the Billings Complex reported by local fishermen, indicated the adaptability of this invasive fish to the new habitat, suggesting that it may possess a central role as the dominant zooplankton predator in the system. [ABSTRACT FROM AUTHOR]

Examination of the holotypes of two nominal species, Encrasicholina heteroloba (Rüppell 1837) and E. devisi (Whitley 1940), both previously recognized as valid species, was revealed to represent a single species. Accordingly, E. heteroloba is regarded as a senior synonym of E. devisi. Encrasicholina pseudoheteroloba (Hardenberg 1933), previously regarded as a junior synonym of E. heteroloba, is in fact a valid species in its own right and is therefore elevated accordingly. Encrasicholina heteroloba is distinguished from its congeners by a long upper jaw (posterior tip extending beyond the posterior margin of the preopercle), three unbranched rays in the dorsal and anal fins, and a shorter relative head length (24.9-28.9 % of standard length). Encrasicholina pseudoheteroloba differs from its congeners in having a long upper jaw (posterior tip extending beyond the posterior margin of the preopercle) and two unbranched rays in the dorsal and anal fins. A neotype is designated for E. pseudoheteroloba. [ABSTRACT FROM AUTHOR]

A new species of the clupeid genus Scombroclupea is described from the Upper Cretaceous (Cenomanian) Plattenkalk locality 'Loma la Mula' in Coahuila, northeastern Mexico. The material provides new osteological data for the genus, which clarify its systematic position. The Mexican Scombroclupea points to an occurrence of the genus in the western Tethys and indicates a vicariant event between S. macrophthalma from Lebanon and Croatia and the new species described herein. The analysis of the functional morphology of Scombroclupea supports the reconstruction of an oscillatory locomotion mode in this genus. [ABSTRACT FROM AUTHOR]

In this study, twelve polymorphic microsatellite markers were developed for Coilia ectenes (synonym C. nasus). In a sample of 30 C. ectenes individuals in a Wuhan population from Yangtze River, a total of 78 alleles were detected, and the number of alleles per locus ranged from 3 to 12. The observed and expected heterozygosities ranged from 0.100 to 1.000 and from 0.098 to 0.899, respectively. Six loci significantly deviated from the Hardy-Weinberg equilibrium after Bonferroni correction ( P < 0.004), and no significant linkage disequilibrium between pairs of loci was found. The applicability of these markers in a closely related species, C. mystus, was evaluated by cross-species amplification. These microsatellite markers will be useful in studies on population genetics, conservation genetics, and fishery management and in the construction of genetic linkage maps of C. ectenes and C. mystus. [ABSTRACT FROM AUTHOR]

This study recognized a W-shaped occipital articulation associated with the first vertebra in pristigasterids, chirocentrids, and clupeids as a unique character among teleosts, based on an evaluation of 43 species within 40 genera of these three families of the Clupeoidei. This occipital articulation is accompanied by an anterior extension of the neural arch bases, which are autogenous with the first vertebral centrum. In chirocentrids and many of the clupeid species examined, the anterior extension occurs on the second vertebra, and similar occipital articulation is found between the first and second vertebrae. The W-shaped occipital articulation is not found in any other teleosts, including Denticeps (suborder Denticipitoidei), which is thought to be a sister group to the suborder Clupeoidei. The W-shaped occipital articulation is absent in the other family of the Clupeoidei, Engraulidae, based on an evaluation of 11 species in 10 genera. Instead, the convex anterior surface of the first vertebral centrum forms a condyle that articulates with the basioccipital, and the neural arches fuse with the centrum behind this condyle. Therefore, it is unclear whether the anterior extension of the first vertebral neural arch bases, which causes the W-shaped occipital articulation, occurs in engraulids. Based on an evaluation of the osteological development of Konosirus punctatus and Engraulis japonicus, the cartilaginous neural arch bases of the first and second vertebrae extend anteriorly at an early developmental stage in the former, whereas no anterior extension of the first vertebral neural arch bases occurs at any developmental stage in the latter. Therefore, the anterior extension of the neural arch bases, which causes the W-shaped occipital articulation, seems to be a unique character of pristigasterids, chirocentrids, and clupeids among teleosts. Within the recent phylogenetic context, this character may be a synapomorphy of these three families. [ABSTRACT FROM AUTHOR]

Abstract  Molecular characters may offer a useful alternative to confidently estimate the phylogenetic position of paedomorphic taxa otherwise difficult to place based on morphology because of the reduction or absence of characters in their larvae-like adult stage. Here, we sequenced the complete mitogenome of a remarkable undescribed marine paedomorphic clupeiform fish to gain insight into its phylogenetic position. Of a length of 17,507 bp, this mitogenome exhibits a unique gene order within the Teleostei because of the inversion of the contiguous tRNAGln and tRNAIle within the IQM region and the presence of a putative second control region inserted between these tRNAs. Mitogenomic data from 27 clupeiform species and 22 non-clupeiform species were subjected to partitioned maximum likelihood and Bayesian analyses. All resultant phylogenetic trees strongly supported the placement of this undescribed taxon within the order Clupeiformes, suborder Clupeoidei, and the family Clupeidae, as the sister group of the tribe Spratelloidini (Jenkinsia + Spratelloides) of the subfamily Dussumieriinae. Together, they form a monophyletic group with Chirocentrus and, possibly, Etrumeus. Despite its overall resemblance to Sundasalanx, this undescribed taxa (Clupeidae gen. et sp. indet.) is not closely related to that genus and represents an independent paedomorphic lineage within the Clupeoidei. [ABSTRACT FROM AUTHOR]

We used sequences of mitochondrial cytb and 16SrRNA gene segments in order to clarify the genetic diversity and population structure in three Chinese estuary populations of Coilia mystus: 21 individuals from ChangJiang River (Yangtze River) estuary, 22 from MinJiang River estuary, and 22 from ZhuJiang River (Pearl River) estuary (65 individuals total). We obtained 607 base pairs of consensus cytb sequence. Thirty four distinct haplotypes were detected among the 65 cytb sequences. The indexes of nucleotide diversity ( π) in these three populations were ChangJiang 0.533%, MinJiang 1.135%, and ZhuJiang 0.268%. MinJiang is the largest of the three populations. Genetic distances within the populations were between 0.3 and 1.2%, and 0.8 to 10.8% among populations. The largest genetic distance was 10.8% between the ChangJiang and ZhuJiang populations, and the smallest was 0.8% between MinJiang and ZhuJiang populations. Analysis of molecular variance (AMOVA) analysis revealed that variation among populations accounts for 90.25% of total variation, suggesting that this is the main source of total variance. We obtained 470 base pairs of consensus sequence of 16SrRNA. We detected 19 distinct haplotypes among the 65 sequences. The indexes of nucleotide diversity ( π) in these three populations were ChangJiang 0.108%, MinJiang 0.843%, and ZhuJiang 0.097%. MinJiang is also the largest among these three populations. Genetic distances were between 0.1 and 0.9% within populations and 0.5 to 1.9% between populations. The largest genetic distance was the 1.9% between the ChangJiang and MinJiang populations, and the smallest was 0.5% between the MinJiang and the ZhuJiang populations. AMOVA analysis disclosed that variation among populations accounts for 74.61% of total variation, suggesting that this is the main source of total variation. The results of this study suggest that the three Coilia mystus populations, especially the most isolated Changjiang population, have developed significant genetic structure. [ABSTRACT FROM AUTHOR]

Bay anchovy,Anchoa mitchilli, is an ecologically important species in coastal systems, acting as predators on zooplankton while serving as prey for many birds and economically important finfish species. Despite the importance of bay anchovy, limited information exists concerning reproductive biology and egg mortality from the northern parts of its range. Spawner demographics suggested Hudson River fish were older and larger than reported elsewhere. Egg mortality rates were higher in the Hudson River than reported in more southerly systems. Differences in the reproductive biology of bay anchovy suggest either anthropogenic factors or latitudinal differences between populations exist and therefore should warrant further investigations on this species in the northern portions of its range [ABSTRACT FROM AUTHOR]

Sequence variation of a fragment of the mitochondrial cytochromeb(cytb) and cytochromecoxidase subunit I (COI) gene was examined using polymerase chain reaction and direct sequencing among three populations of Japanese anchovyEngraulis japonicusfrom the Yellow Sea and East China Sea. A total of 24 and 47 nucleotide sites were detected variable defining 29 and 32 haplotypes in cytband COI data, respectively. All variable sites except one in COI were silent in the two sets of sequences. The Ewens–Watterson test indicated that the observed allelic configurations in both data sets were in full agreement with neutral expectations. The variation level was high, withh = 0.957 ± 0.018,π = 0.644 ± 0.387 (%) in cytbdata set andh = 0.958 ± 0.021,π = 0.640 ± 0.386 (%) in COI data set, respectively. However, at the population level,Fstvalues between pairs of populations were not significantly different from zero (P > 0.05) in both data sets. The analysis of haplotype frequency distribution showed no significant differences among populations. Similarly, the analysis of the partitioning of molecular variance indicated that all or almost all of the genetic variation was distributed within populations. Based on the data from this study, the existence of separate genetic stocks in this area were not detected. Mixing of stocks to some extent in migration cycle and dispersal capacity of anchovy's planktonic larvae could be the reasons for genetic homogeneity in this species in the Yellow Sea and East China Sea. [ABSTRACT FROM AUTHOR]

An increasing demand for stocking of hatchery-reared ayu,Plecoglossus altivelis, has aroused concerns about their genetic status which has an effect on their post-stocking performance and the conservation of native biodiversity. Instead of costly analysis, fluctuating asymmetry (FA) was examined to test its suitability as an indirect measure of genetic diversity. Two bilateral traits, pectoral and pelvic fin rays, were targeted, and two wild and four hatchery populations of ayu were sampled for comparison. Frequency of FA in soft-rays was not similar between specimens in both pelvic and pectoral fins. The wild populations did not show FA incidences lower than the hatchery populations, suggesting a considerable degree of environmental stress operating in the wild populations. Comparison between the hatchery populations showed overall increasing FA incidence with the decrease in genetic diversity, although the correlation was not complete in detail. In conclusion, FA can be used as a convenient tool to compare genetic status, but quantified evaluation is rather limited to monitoring changes in the genetic variation within a hatchery population. [ABSTRACT FROM AUTHOR]

A newly designed frame trawl with a 5 m2 mouth area was constructed for quantitative sampling of larval and juvenile pelagic fishes and its performance was tested in the ocean. Towing depth of the trawl was easily controlled by adjusting the warp length, and the stability at depth increased with decreasing weight of the net in water. Larval and juvenile fishes were sampled using the trawl at stations in the Kuroshio–Oyashio transition region from 29 May to 24 June 1998. A total of 44 oblique tows were conducted and towing depths of the frame trawl had a high degree of stability despite the various sea conditions and the fluctuations in the ship speed. Larvae and juveniles of Japanese anchovy Engraulis japonicus and Myctophidae made up the majority of the specimens. It was concluded that the newly constructed trawl was appropriate for the quantitative sampling of pelagic fish larvae and juveniles. [ABSTRACT FROM AUTHOR]

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to investigate the distribution of manganese (Mn) in Atlantic herring (Clupea harengus L.) otoliths. An unusual pattern of Mn concentration, which has not previously been reported in fish otoliths, was observed. Time-resolved plots (time roughly equivalent to ablation depth) of the Mn signal recorded in the ICP-MS detector during ablation of otoliths contained a distinct peak, suggesting that elevated Mn concentrations were specific to certain regions. Ablation inside and outside of the otolith core revealed that the region of high Mn concentration coincided with the ablation of the core. It was initially suggested that Mn from the gravel substrate on which herring eggs are incubated is incorporated into the otolith core, producing elevated Mn concentrations in this region. It was hypothesised that otoliths from fish whose eggs are not incubated in gravel will not contain high Mn concentrations at the core. To test this, otoliths of sprat (Sprattus sprattus), which have a pelagic embryological stage, and from reared herring, which were incubated on glass plates, were analysed using LA-ICP-MS. Peaks in the Mn signal were observed during the ablation of cores from some sprat and reared herring otoliths, indicating that incubation on a gravel substrate is not necessary for the accumulation of Mn at the otolith core and that otoliths from both pelagic and demersally spawning fish species can contain elevated Mn concentrations. The results suggest that Mn concentrations at the otolith core do not reflect the external environment of the developing embryo. Two other hypotheses are considered. A dramatic increase in Mn concentrations in the egg, associated with embryological development, may produce elevated Mn levels at the otolith core. Alternatively, the high levels of Mn observed at the otolith core may reflect spatial variation in the crystal structure of the calcium carbonate portion of the otolith. The possible influence of physiological or structural factors on the chemical composition of the otolith core may confound the environmental signal in this region of the otolith. This has important implications for the interpretation of otolith chemistry data. [ABSTRACT FROM AUTHOR]

This article describes the life-history strategy of the blue sprat Spratelloides robustus in South Australia and compares the demographic traits observed with those of other clupeoids. Validation studies that involved marking the sagittae of captive fish with oxy-tetracycline suggested that growth increments are deposited daily. The oldest fish examined was 82 mm caudal fork length and 241 days old, which suggests S. robustus may live for less than 1 year. Growth rates were high during larval stages (0.34 mm day-1) and remained high throughout juvenile (0.33 mm day-1) and adult stages (0.19 mm day-1). S. robustus reached 50% maturity at approximately 60 mm caudal fork length after approximately 135 days. Spawning occurred from October to February (spring to late summer) and larvae were found mainly in Spencer Gulf, Gulf St Vincent, and Investigator Strait. Females spawned multiple batches of demersal eggs every 1–2 days. Batch fecundities were low (mean=756, SD=341) and increased linearly with length and weight. The life history of S. robustus is dissimilar to other small to medium-sized temperate clupeoids, but similar to those of many small sub-tropical and tropical clupeoids, including other Spratelloides species. Gulf St Vincent and Spencer Gulf may be considered to be "seasonally subtropical systems" in an otherwise temperate region that support a suite of species, including S. robustus, that have life-history strategies similar to those of sub-topical and tropical taxa. [ABSTRACT FROM AUTHOR]

The haemoglobin systems of the order Clupeiformes have been studied by several researchers in 41 species belonging to three out of its five families. Most of them were investigated in the native form using electrophoretic methods, and a few were also examined from the functional point of view. Both approaches corroborate the widespread view that acidic and basic haemoglobin components, which are structurally and functionally distinct, may be present in teleost fish. However, the former are always present, whereas the latter are often lacking, depending on the taxonomic group. Both kinds of components are found in families Clupeidae and Pristigasteridae, but only acidic ones in Engraulidae. Most electrophoretic patterns show high multiplicity, and chiefly concern the acidic components. Ontogenetic variation was described in three species. Individual variants were also observed in other species, although some of these might be due to ontogenetic variations rather than genetic polymorphism. [ABSTRACT FROM AUTHOR]

Estimates the advective flux of anchovy eggs from offshore spawning sites into coastal Enshu-nada Sea and its effect on the shirasu catch. Examination of data on oceanographic conditions and number of anchovy eggs; Finding that the period of low anchovy stock size, anchovy shirasu catch in the central Pacific Coast of Japan was dependent on anchovy egg abundance; Observation that more eggs were spawned in the coastal region in 1995 and 1998.

The article presents information on a study related to clupeidae which is known as the threatened fish of the world. The study shows that clupeidae is an anadromous fish and spends most of its life at sea. The study determines that clupeidae only enters the freshwater river in which it was born to spawn. The study findings suggest that during the first year of their lives, clupeidae live in river mouths and from the starting of the second year of their lives, clupeidae begin to swim into sea for growth.