Distribution of Karlodinium veneficum in the coastal region of Xiangshan Bay in the East China Sea,as detected by a real-time quantitative PCR assay of ribosomal ITS sequence

Athecate dinoflagellate Karlodinium veneficum is a universal toxic species possessing karlotoxins recognized especially as ichthyotoxic as well as cytotoxic and hemolytic. Blooms of K. veneficum, both single-species or accompanied with other species, occurred more frequently worldwide in recent years, including the coastal region of China. Normally, K. veneficum present in relatively low abundance in phytoplankton communities in estuary regions. Being small and difficult to identify with light microscopy, it has been ignored for a long time till its blooming and toxins being confirmed. How it presents in background level and what is its relationship with critical geological and hydrological environment factors are basically not clear. In this study, the paper reports the application of a real-time quantitative PCR (qPCR) method to investigate the abundance and distribution of K. veneficum in the coastal waters of Xiangshan Bay in the East China Sea (ECS), a typical bay area of harmful algae blooms and heavily affected by anthropogenic activities. The real-time qPCR assay came out being an efficient method at detecting even low cell densities of K. veneficum of different genotypes. A total of 38 field samples of surface (0.5 m) and bottom water (9–100 m in depth) were analyzed and 12 samples were found positive for K. veneficum. At least 3 genotypes of K. veneficum present in this region. Temperatures in sites of K. veneficum positive ranged from 21.7 to 23.4 °C, and salinity levels were between 21.1 and 26.3. The K. veneficum distributed quite extensively in the waters of Xiangshan Bay, cell abundance varied from a low of 4 cells/L to a maximum of 170 cells/L. Most of the samples containing K. veneficum were collected from bottom water in different sites. At three of the 19 sampling sites, K. veneficum was detected in both surface and bottom water samples. Especially at sampling site near Beilun port, where the water is typically muddy with low transparency, relative high cell numbers of K. veneficum were found in both surface and bottom waters. Mixotrophy and vertical migration of K. veneficum could be important eco-physiological factors to consider in terms of understanding these distribution characteristics. The ideal conditions for K. veneficum growth and aggregation in this area still needs further study.     

Humpback whale singing activity off the Goan coast in the Eastern Arabian Sea

For over two decades, passive acoustic monitoring (PAM) methods have been successfully employed around the world for studying aquatic megafauna. PAM-driven studies in Indian waters have so far been relatively very scarce. Furthermore, cetacean populations inhabiting the north western Indian Ocean are far less studied than those in many other regions around the world. This work likely constitutes the first systematic study of the vocal repertoire of humpback whales (Megaptera novaeangliae) at a near-shore site along the western coast of India. Analysis of the observed vocalizations provides an insight into the behaviour of the species. This is significant as it assists in developing a better understanding of the habitat use of the non-migratory Arabian Sea humpback whale population. In contrast, other breeding populations such as those around the North Atlantic, South Pacific and Australia have been relatively well studied. Underwater passive acoustic data were collected during March 2017 using an autonomous logger at a shallow-water site off the eastern edge of Grande Island off the coast of Goa. Humpback whale vocalizations were found to occur over multiple days in the recordings. Time–frequency contours of individual units of vocalization were extracted with the aid of an automatic detection technique and the characteristics of the units were measured. Further, successive units were analysed for formation of phrases and themes. Reconstruction of putative songs from the identified units and themes was not possible due to the limitations imposed by the nature of data collection. Detailed analyses of units, phrases and themes are presented.     

International Courts and State Compliance: An Investigation of the Law of the Sea Cases

This article investigates the effect of dispute settlement decisions under the 1982 United Nations Convention on the Law of the Sea (UNCLOS) and whether and how states, particularly great powers, comply with these decisions. State practice suggests that an overwhelming majority of the decisions by UNCLOS dispute settlement bodies have been implemented. Significantly, not only small states but also the permanent members of the United Nations Security Council have complied with UNCLOS dispute settlement decisions even when they “lost” in the proceedings that were unilaterally initiated against them.     

Length–weight relationships of six elasmobranch species captured at the artisanal fishery of Margarita Island,Venezuela

This study reports the length – weight relationship (LWR) for five batoid and one shark species, all frequently captured by the artisanal commercial fishery on Margarita Island (10º44’ – 11º10’N and 63º46’ – 64º13’W), Venezuela. In 2013, elasmobranchs captured by the artisanal fleet (using bottom gillnets 200–400 m in length with 5–8 inch mesh size) were identified, sized, weighed and sexed. The value of a ranged from 0.0006 to 0.0351, meanwhile the b value ranged from 2.84 (for pooled Myliobatis freminvillei) to 3.39 (male Mustelus higmani), with r² ranging from 0.920 to 0.991. Differences in LWR due to sex were observed for three elasmobranch species. This study offers LWRs separate for males and females, also for species for which LWRs already exist and thus new knowledge is gained through the estimate presented here.     

Outmigration pathways of stocked juvenile European sturgeon (Acipenser sturio L., 1758) in the Lower Rhine River,as revealed by telemetry

Working towards a future Rhine Sturgeon Action Plan the outmigration pathways of stocked juvenile European sturgeon (Acipenser sturio L., 1758) were studied in the River Rhine in 2012 and 2015 using the NEDAP Trail system. A total of 87 sturgeon of 3 to 5 years old (n = 43 in 2012, n = 44 in 2015) were implanted with transponders and released in May and June in the river Rhine at the Dutch‐German border, approximately 160 km from the sea. In total three sturgeons (3%) were found dead on river banks within seven days after the release. Based upon their wounds these sturgeons were likely hit by ship‐propellers. Tracking results were obtained from 57 (66%) of the sturgeons, of which 39 (45%) indicated movement into the Port of Rotterdam. Here the sturgeons remained for an average of two weeks, which suggests they spent time to acclimatize to higher salinities before entering the North Sea. Of the 45 (52%) sturgeons that were confirmed to have entered the North Sea, ten (22%) were recaptured (mainly by shrimpers and gill‐nets) close to the Dutch coastline; nine were alive and were released. From the results we obtained the preferred outmigration pathways, movement speeds and an indication of impacting factors (i.e. ship propellers and bycatch). Bycatches provided also localisations information in the coastal area. A next step to complete this work would be to assess habitat selection in freshwater and downstream migration of young of the year (YOY sturgeons) in the Lower Rhine.     

渤海湾两株H2亚型禽流感病毒的 遗传进化分析

野鸟是禽流感病毒的自然储存库,病毒可以随着宿主的迁徙传播给其他野鸟与家禽。渤海湾是鸟类南北迁徙的重要停歇地,也是东亚-澳大利西亚鸟类迁徙通道的重要组成部分,每年有大量水鸟在渤海湾停歇,促进了禽流感病毒的传播。为了解渤海湾地区禽流感病毒的传播及进化与水鸟迁徙的相关性,2018年春季鸟类迁徙期间的4和5月份,在渤海湾采集鸻鹬类粪便样品2 120份,对样品进行检测,分离出2株H2亚型禽流感病毒。对这2株H2亚型禽流感病毒进行了分子特征及遗传进化分析,并结合渤海湾水鸟的环志回收数据,对H2亚型病毒的重组及遗传进化与水鸟迁徙的联系进行了分析。结果表明,2株分离株的HA蛋白裂解位点符合低致病性禽流感病毒的分子特征,它们的8个基因片段同源性均不高,其中879-H2N7的8个基因片段分别与我国福建和澳大利亚的毒株同源性最高,遗传关系最近;854-H2N8的8个基因片段分别与我国湖南以及日本、韩国、孟加拉国和越南的毒株同源性最高,遗传关系最近。渤海湾水鸟的环志回收数据分析表明,879-H2N7随着野鸟的迁徙在渤海湾、福建沿海和澳大利亚之间进行传播与扩散;854-H2N8可能跨越东亚-澳大利西亚和中亚-印度两条通道之间进行基因重组和进化,并会随着鸟类迁徙进行传播和扩散。     

Oxynoemacheilus cemali,a new species of stone loach (Teleostei: Nemacheilidae) from the Çoruh River drainage,Turkey

Oxynoemacheilus cemali sp. nov. is described from the Çoruh River drainage in the eastern Black Sea basin. One molecular marker (coI), 25 morphometric and four meristic characters were analysed. Oxynoemacheilus cemali is distinguished from O. kosswigi, O. banarescui, O. samanticus and O. angorae in the Black Sea basin by having a suborbital groove in males, an axillary lobe at the pelvic-fin base, no dorsal adipose crest on the caudal peduncle, a slightly-forked caudal fin and 7–15 dark grey dorsal saddles. Morever, Oxynoemacheilus cemali is distinguished by commonly having 9–15 irregularly-shaped dark-grey bars on the flank posterior to the dorsal-fin origin or, rarely having a mottled pattern or 4–6 irregularly shaped dark-grey bars on the flank posterior to the dorsal-fin origin. Oxynoemacheilus cemali is also distinguished from the closely related species O. araxensis and O. cyri, distributed outside the Black Sea basin, by having 15 and 31 diagnostic nucleotide substitutions in the coI barcode region, respectively.     

Laciniporus arabicus gen. et sp. nov. (Dinophyceae,Peridiniales), a new thecate,marine, sand‐dwelling dinoflagellate from the northern Indian Ocean (Arabian Sea)1

A new thecate, photosynthetic, sand‐dwelling marine dinoflagellate, Laciniporus arabicus gen. et sp. nov., is described from the subtidal sediments of the Omani coast in the Arabian Sea, northern Indian Ocean, based on detailed morphological and molecular data. Cells of L. arabicus are small (16.2–30.1 μm long and 13.1–23.2 μm wide), dorsoventrally compressed, with a small apical flap‐shaped projection pointing to the left. The thecal plate pattern is distinguished by minute first precingular plate and sulcus, which extends into the epitheca, with large anterior and right sulcal plates. The Kofoidian thecal tabulation is Po, X, 4′, 2a, 7′′, 6c, 6s, 5′′′, 2′′′′. Morphologically, the revealed plate pattern has an affinity to the Peridiniales, and LSU rDNA based phylogenetic analyses placed L. arabicus within the Thoracosphaeraceae, close to calcareous‐cyst producing scrippsielloids, predatory pfiesteriaceans, and photosynthetic freshwater peridinioids Chimonodinium lomnickii and Apocalathium spp. However, the thecal plate arrangement of L. arabicus differs noticeably from any currently described dinoflagellates, and the species stands out from closely related taxa by extensive differences in physiology and ecology.     

Consumption rates and prey preference of the invasive gastropod Rapana venosa in the Northern Adriatic Sea

The alien Asian gastropod Rapana venosa (Valenciennes 1846) was first recorded in 1973 along the Italian coast of the Northern Adriatic Sea. Recently, this predator of bivalves has been spreading all around the world oceans, probably helped by ship traffic and aquaculture trade. A caging experiment in natural environment was performed during the summer of 2002 in Cesenatico (Emilia-Romagna, Italy) in order to estimate consumption rates and prey preference of R. venosa. The prey items chosen were the Mediterranean mussel Mytilus galloprovincialis (Lamarck 1819), the introduced carpet clam Tapes philippinarum (Adams and Reeve 1850), both supporting the local fisheries, and the Indo-Pacific invasive clam Anadara (Scapharca) inaequivalvis (Bruguière 1789). Results showed an average consumption of about 1 bivalve prey per day (or 1.2 g wet weight per day). Predation was species and size selective towards small specimens of A. inaequivalvis; consumption of the two commercial species was lower. These results might reduce the concern about the economical impact on the local bivalve fishery due to the presence of the predatory gastropod. On the other hand, selective predation might probably alter local community structure, influencing competition amongst filter feeder/suspension feeder bivalve species and causing long-term ecological impact. The large availability of food resource and the habitat characteristics of the Emilia-Romagna littoral makes this area an important breeding ground for R. venosa in the Mediterranean Sea, thus worthy of consideration in order to understand the bioinvasion ecology of this species and to control its likely further dispersal.