Northern Waters Research Articles

New records of two southern fishes found in northern waters of the Iberian Peninsula

New records of two southern fishes found in northern waters of the Iberian Peninsula

Nations put science before fishing in the Arctic.

Historic fishing ban gives scientists time to probe ecology as northern waters warm.

Spatial variation of stable isotopic composition in surface waters of the Huai River basin, China and the regional hydrological implication

AbstractOxygen (δ18O) and hydrogen (δD) stable isotopes in the surface waters of the Huai River basin were analyzed in this study. Results indicated the northern waters had higher δ18O and δD than the southern waters, the water δ18O and δD increased along the water flow directions. These variations mostly resulted from the spatial differences of precipitation and evaporation. Comparing with published different continents' river water δ18O data, this study suggests that evaporation effect is a more plausible interpretation than altitude effect as the cause of δ18O increasing from upriver to downriver waters. This region's local surface water line (LSWL, δD = 5.36δ18O − 18.39; r2 = 0.84) represents one of the first presented LSWLs in eastern China. The correlation between d-excess and δ18O demonstrates this region is dominated by the Pacific oceanic moisture masses in summer. Comparing the various LSWLs from eastern China and eastern United States river waters, this study proposes a hypothesis that the water LSWLs slopes of lower latitude regions may be less than those of higher latitude regions within similar topographic areas. This hypothesis may be tested in other geographically comparable coupled areas in the world if corresponding large-scale data can be found.

Primnoidae (Cnidaria: Octocorallia) of the SW Indian Ocean: new species, genus revisions and systematics

The Indian Ocean is one of the least-studied areas of the world’s largest biome, the deep sea. On an expedition to five seamounts along the SW Indian Ocean Ridge in 2011, thousands of specimens from deep-sea habitats were procured. We propose five new species of Primnoidae, a predominantly deep-sea octocoral family. The new species include three from the genus Narella, and one new species each from Primnoa and Primnoeides; the latter genus is revised and we propose Digitogorgia as its junior synonym. We support the new species placement within Primnoidae through taxonomic descriptions and the most comprehensive molecular phylogenetic analysis of any deep-sea coral family (81 species across 29 genera). We also present a rare example of polar submergence (from the Antarctic shelf into deeper more Northern waters).

CATCH RATE FLUCTUATIONS OF SKIPJACK AND OTHER TUNA RESOURCES IN THE NORTHERN WATERS OF ACEH

The most dominant species of the ''large pelagic group" landed in Lampulo, Aceh,were skipjack, yellowfin tuna and small tuna. Thcse fish were caught by mini purse seine through fishing activities carried out on a dailv basis.

ISOTOPIC TEMPERATURES FROM THE EARLY AND MID-PLIOCENE OF THE US MIDDLE ATLANTIC COASTAL PLAIN, AND THEIR IMPLICATIONS FOR THE CAUSE OF REGIONAL MARINE CLIMATE CHANGE

Mean seasonal extreme temperatures on the seafloor calculated from the shell δ18O of the scallop Placopecten clintonius from the basal part of the early Pliocene Sunken Meadow Member (Yorktown Formation) in Virginia are very similar to those from the same horizon at the latitude of Cape Hatteras in North Carolina (∼ 210 km to the south). The lowest and highest temperatures calculated from each shell (using δ18Oseawater = 0.7‰) give mean values for winter and summer of 8.4 ± 1.1 °C (± 1σ) and 18.2 ± 0.6 °C in Virginia, and 8.6 ± 0.4 °C and 16.5 ± 1.1 °C in North Carolina (respective median temperatures: 13.3 °C and 12.6 °C). Patterns of ontogenetic variation in δ18O, δ13C and microgrowth increment size indicate summer water-column stratification in both areas, with summer surface temperatures perhaps 6 °C higher than on the seafloor. The low winter paleotemperatures in both areas are most simply explained by the greater southward penetration of cool northern waters in the absence of a feature equivalent to Cape Hatteras. The same current configuration but a warmer general climate can account for the high benthic seasonal range (over 15.0 °C in some cases) but warmer median temperatures (15.7–21.3 °C) derived from existing δ18O data from scallops of the higher Yorktown Formation (using δ18Oseawater = 0.7‰ for the upper Sunken Meadow Member and δ18Oseawater = 1.1‰ for the mid-Pliocene Rushmere, Morgarts Beach, and Moore House members). Existing δ18O data from the infaunal bivalve Mercenaria of the Rushmere Member yields a similarly high median temperature (21.6 °C) but a low seasonal range (9.2 °C), pointing to the periodic influence of warm currents, possibly at times when the Gulf Stream was exceptionally vigorous.

Constraints on Canadian Arctic maritime connections

Sea-ice retreat suggests the possibility of future safe and efficient Arctic marine transportation. The paper first demonstrates that maritime passages in the Canadian Arctic archipelago are complex and include several routeways. This is followed by an analysis of the vessel types and ownership structure of ships sailing in Canada’s northern waters as well as the cargo types and their tonnages. This leads into a detailed examination of shipping route patterns and their changes over the past decade. The network structure of different commodity groups provides evidence of diversity in the patterns of trade in Arctic waters between Canadian and foreign fleets. In assessing future trends, the paper identifies key challenges in terms of market changes, regulatory regimes and risk.

豪北部地域における「脅威」と境界管理

豪北部地域における「脅威」と境界管理

Morphological identification and DNA barcoding used for diet analysis of gilthead seabream (Sparus aurata) in its expanding northerly range

The gilthead seabream, Sparus aurata, is common in the Mediterranean Sea and along the Atlantic coasts of Portugal, Spain and France. Abundance of S. aurata has recently increased along the Brittany coast, showing good adaptation and acclimatisation to northern waters away from its original distribution range. The physiological adaptations (diet, reproduction, growth) of this fish to colder water could even lead to its colonisation of the English Channel. The ability to eat and digest hard prey makes this fish an important consumer of bivalves. The aim of this study was to make a preliminary evaluation of the diet of the gilthead seabream in its northern range of distribution. Prey items from stomach contents of wild adults from various sites along the East Atlantic coast of France to the English Channel were identified morphologically when it was possible, e.g. in presence of decapod appendices, shells of bivalves, or using DNA barcoding. Diet composition was analysed against sites, fish length and month of sampling using the frequency of occurrence (%F) and weight relative proportion (%W). Results showed that the diet of S. aurata was mainly composed of bivalves, malacostracans and gastropods with a huge dominance of Mytilus sp. (%F = 51.5 and %W = 40.2). This first diet analysis of individuals from the northern range of the species distribution showed its ability, as an opportunistic feeder, to find prey in newly colonised ecosystems and its preference for some organisms, especially mussels.

Trends in derelict fishing nets and fishing activity in northern Australia: Implications for trans-boundary fisheries management in the shared Arafura and Timor Seas

Fishing is the major human activity within the ‘semi-enclosed’ Arafura and Timor Seas (ATS). Since the early 2000’s, Australia’s sparsely populated, remote northern shores have reported very high levels of foreign, fishing-related marine debris. Limited information is available about the temporal and spatial variation of this fishing debris or its origin. We examine trends in derelict fishing nets (and marine debris) at multiple sites in the Northern Territory and Gulf of Carpentaria and, explore its potential origin and relationship with fishing activity in the region. Further, we investigate temporal trends in domestic and foreign fishing activity (legal and illegal) in the ATS and also foreign fishing vessel sightings in the northern waters of the Australian Exclusive Economic Zone (AEEZ). Our results confirm that foreign fishing debris (nets, rope and gear) is the major source of marine debris (63%) on Australia’s northern shores. Over the period 2003–2008, a total of 2305 derelict fishing nets were washed ashore; of these, 89% were identified of foreign origin (i.e. manufacture), compared to 11% attributed to Australian fishing vessels or fisheries. Industrial foreign and Indonesian-flagged fisheries – particularly, illegal, unreported and unregulated (IUU) trawling activity – and small-scale Indonesian IUU fisheries (primarily targeting shark) in the Arafura Sea are likely the major sources of these nets. Derelict nets comprised mostly trawl nets (71%) and gillnets/drift nets (12%); with 95% of all identified net sourced from the nations of Taiwan, Indonesia, Thailand and Korea. Our data also supports consistent under-reporting by these foreign trawl operators in the Indonesian Exclusive Economic Zone (IEEZ) of the ATS.The arrival and increase in derelict nets in northern Australia post-2000 coincided with sharp increases in both industrial foreign fishing (illegal, legal) and Indonesian small-scale fisheries within the IEEZ waters of the ATS. Including, over the period 2000–2007, a 2-fold increase in ‘non-motorised’ vessels, and a 5-fold increase in the number of motorised vessels, particularly in vessels less than 5GT. Further, this major increase in fishing activity in the IEEZ corresponded to a 3-fold increase in foreign fishing vessels (FFVs) (legal, illegal) sightings in northern Australian waters. Within the AEEZ, derelict net loads and sightings of illegal FFVs, both peaked and reached a maximum in 2005 (188kgkm−1yr; 6956 vessels) and then sharply reduced (>80%) following major border control, surveillance and security operations in the northern Australia in 2005–2006. However, post-2007, illegal FFV sightings inside the AEEZ have increased again. Significantly, derelict nets and small-scale IUU fishing activity in the AEEZ is linked to a broader pattern of poverty, overfishing and displacement of small scale fishers in coastal fisheries in the Arafura Sea (and South East Asia), due primarily to the expansion of industrial (illegal, legal) trawl fisheries. Strengthening of regional fisheries management (particularly under the RPOA-IUU) is urgently required to tackle IUU fishing, the key source of fishing debris in the ATS. While fisheries capacity reduction is a critical priority, it needs to be supported by a regional multi-sectoral response framed within the context of food security and rural economic development.

Spatial Distribution and Habitat Use Patterns of Humpback Whales in Okinawa, Japan

Abstract. Detailed knowledge of the population of humpback whales (Megaptera novaeangliae) in Okinawa is important for conservation management in this area; however, information on the spatial distribution of this population is limited. In this study, we investigated the distribution of whales using data on the sighting locations, water depth, and reproductive status of whales collected over 21 years in the area of Kerama and Ie Islands, Okinawa, Japan, one of the breeding grounds in the Western North Pacific. Of 1,402 whales that were photo-identified (856 males, 100 singers, 150 females, and 296 females with a calf), males, females, and singers were mainly distributed in deep offshore waters, while females with a calf were distributed in shallow interisland waters. The results suggest that certain reproductive activities, such as mating behavior or competition among males over females to mate, might occur in the offshore northern waters of Kerama Islands and western waters of Ie Island, while nurturing ...

The Aucellina biostratigraphy of the Upper Albian (Early Cretaceous) of the Kirchrode I cored borehole, Hannover-Kirchrode, northern Germany

Abstract The Aucellina biostratigraphy of the Upper Albian Kirchrode Marls Member succession in the Kirchrode I (1/91) cored borehole is described and the fauna illustrated. The borehole commenced at an unknown depth below the Early Cenomanian marls of the Bemerode Member, but higher beds of the Kirchrode Marls and the basal beds of the Bemerode Member were exposed in the Mittellandkanal and its Stichkanal extension at Misburg. The borehole and surface exposures permit a virtually complete Late Albian succession of Aucellina species to be observed. Published Aucellina range data from the borehole are reassessed and it is suggested that the lower part of the recorded range is based partly on misidentifications of fragments of thin-shelled bivalves such as Syncyclonema and Amussium. Aucellina appears in the borehole succession within the upper part of the Callihoplites auritus ammonite Subzone (Mortoniceras inflatum Zone) and continues to the top of the borehole succession within the Preaeschloenbachia briacensis ammonite Subzone (Stoliczkaia spp. Zone). Aucellina from higher in the briacensis Subzone collected from the Misburg Mittellandkanal section are also discussed and illustrated. There is some evidence that Aucellina occurs typically at levels in the borehole containing predominantly Boreal European Province ammonites, supporting the general inference that Aucellina lived in cooler northern waters. In contrast, Aucellina is poorly represented in intervals with Tethyan ammonites and thin-shelled inoceramids (e.g. the Mortoniceras (Durnovarites) perinflatum Subzone, Stoliczkaia spp. Zone). The briacensis Subzone, with an admixture of Tethyan (Stoliczkaia) and Boreal ammonites contains a distinctive, taxonomically highly diverse Aucellina assemblage. Relevant taxonomic research on European Late Albian and Early Cenomanian Aucellina faunas is reviewed. The Late Albian Aucellina succession in the borehole differs from that established from partially correlative successions in England.

Halosaur fishes (Notacanthiformes: Halosauridae) from Atlantic Spanish waters according to integrative taxonomy.

From 2009 to 2011 thirty-five specimens belonging to six halosaurid species of the family Halosauridae were captured in two different locations in the northern waters of Spain. The specimens were identified as belonging to the genera Halosauropsis Collett, 1896, Halosaurus Johnson, 1864 and Aldrovandia Goode & Bean, 1896, including the following species: Halosauropsis macrochir (Günther, 1878), Halosaurus ovenii Johnson, 1864, Halosaurus johnsonianus Vaillant, 1888, Aldrovandia affinis (Günther, 1877), Aldrovandia phalacra (Vaillant, 1888) and Aldrovandia oleosa Sulak, 1977. The morphometric measurements and meristic characters of these specimens are given. As a result, a new northern limit of distribution of A. oleosa from the northeastern Atlantic is reported. Using a taxonomical integrative approach, the mitochondrial DNA COI gene sequences from all individuals where determined and their comparison with morphological characters showed no incongruities. Among these specimens, the highest genetic distance within species was 0.8% while the lowest value between species was 3.3%. This ample barcoding gap has allowed the delimitation and assignment of all species reported in a way that matches the traditional taxonomical methods previously employed.

Preliminary study of the sea surface temperature (SST) at fishing ground locations based on the net deployment of traditional purse-seine boats in the northern waters of Aceh — A community-based data collection approach

Reconstruction projects after the Indian Ocean Tsunami of December 26, 2004 were typically contracted out to implementing partners or government agencies. One of the few projects directly implemented by the Body of Rehabilitation and Reconstruction (BRR) was funded by the Asian Development Bank (ADB) to help reestablish fisheries. During the course of the project, 151 GPS-enabled depth sounders with data-logging devices were installed on various types of artisanal fishing boats engaged in the different types of fishing strategies in Aceh such as purse-seine, drop-line, long-line, and gill net fishing. These devices were configured to automatically record time, position, speed, water depth, and sea surface temperature (SST) every time the boat moved 30 m. This study examines the relationship between the sea surface temperature (SST) and the net deployment (ND) of traditional purse seine fishers. The data consists of 922 data sets (6,170,648 data points) collected from 45 purse seine boats between June 2007 and May 2009. Among the data, 1,619 data points indicated the total number of ND; the nets were deployed only when schools of fish were actually sighted. The results indicate that the most frequent SST for ND is 28–28.5°C±0.1365°C with a mean standard error of 0.0117% in a 95% confidence interval. This study has demonstrated that the data gathered from the fishermen (community-based approach) has near-real-time character and, consequently, is an important source for the monitoring and managing of the local fish stocks.

Long range airgun inter-pulse noise field in offshore northern Australian waters

Elevated ambient noise levels have been shown to affect marine fauna communication. The effects due to increased noise levels from the multipath propagation and reverberation of airgun pulses over large distances is a relatively new area of interest. This research examines a distant seismic survey opportunistically recorded at two locations during a long-term monitoring program in the Timor Sea, Australia. During the analyzed period, the survey was between 168 and 235 km from the Autonomous Multichannel Acoustic Recorders (AMAR). The noise levels between airgun pulses were examined using an incremental computation method based on calculating the root-mean-square sound pressure level in 125 ms sub-intervals. These were compared to ambient noise levels from the month prior to commencement of the seismic survey and during line turns. The received pulse levels and length differences, and therefore inter-pulse noise field, between the recorders were greater than expected given the proportional distance to sour...

The spatio-temporal distribution and population structure of green turtles (Chelonia mydas) in New Zealand

ABSTRACTDespite being endangered internationally and protected nationally, little consideration has been given to the occurrence of green turtles (Chelonia mydas) in New Zealand. New Zealand lies on the southern boundary of the distributional range of green turtles in the southwestern Pacific, with individuals found within these waters historically considered to be occasional visitors or stragglers incidentally carried by ocean currents. However, the present work shows that green turtles are present year round in New Zealand’s northern waters (c. 34°–38° S). A review of sighting, stranding and incidental capture data collected between 1895 and 2013 illustrate New Zealand’s green turtle population comprises post-pelagic immature juveniles to large subadults. The female:male sex ratio of 1.7:1 is similar to those reported from warm temperate foraging grounds in eastern Australia. A subsample of new recruits indicates green turtles recruit to neritic habitats at approximately 40.8 cm curved carapace length. This study suggests that New Zealand’s neritic habitats constitute a transitional developmental ground for post-pelagic immature green turtles. We observed an exponential increase in the number of documented records over time, though whether this is due to increased numbers of turtles or increased reporting rates, or both, is unclear and warrants further investigation. More broadly, this work provides a baseline understanding of the ecology of green turtles at the edge of their range, providing opportunities to investigate regional niche modelling and connectivity of this highly mobile species, while also monitoring broad-scale effects of climate-induced environmental change.

Temporal and spatial patterns of reproductive indices of European hake (Merluccius merluccius) in the northern North Sea and Norwegian coastal areas

Spatial and temporal patterns of reproductive maturity were examined for European hake (Merluccius merluccius) in the northern North Sea, the Skagerrak and the Norwegian mid-west coast. Maturity stages based on macroscopic examination of gonads and Gonadosomatic Index data were collected from annual scientific surveys conducted in winter, summer, and autumn 2011–2015. Our observations show that spawning activity is highest in July in the central and northern North Sea. Very few hake in spawning condition were found in January and February in the northern North Sea and Skagerrak. Macroscopic staging showed high numbers of post-spawning hake in October/November along the Norwegian west coast north of 62°N, suggesting that main spawning occurs in this area in August/September. Fish in spawning condition occurred mainly in depths from 80–120m at stations with sea surface temperatures between 12 and 15°C and bottom temperatures of 6.5–8.5°C. Our results confirm that European hake has an extended spawning season with a peak later in the year in more northern waters. Occurrence of spawning north of 62°N along the Norwegian coast and an intra-annual variation of length frequency distributions indicate migrations and more complex population dynamics of hake in its northern range than previously assumed.

Myndighetsutøver, ressursforvalter og livredder – den russiske kystvakten i støpeskjeen

The Russian Coast Guard, or Beregovaya okhrana, was formally established in 2007 and plays a crucial role in the management of natural resources located in the vast maritime areas under Russian jurisdiction. The purpose of this article is to shed light on the Coast Guard’s organisation, capabilities and operations in the maritime areas that surround the Russian Federation, and to discuss the service’s ability to effectively perform its missions, now and in the period up to 2020. Special emphasis is placed on the situation in the northern waters. In the Barents Sea, the Russian Coast Guard cooperates closely with its Norwegian counterpart. This cooperation has existed for a long time, and it has not been adversely affected by the general deterioration of Russian–Western relations after Russia’s 2014 intervention in Ukraine and the subsequent freeze in military-to-military cooperation. The article argues that Norway and Russia have a common interest in continuing the cooperation on non-military issues such as maritime search and rescue, fisheries management and law enforcement at sea. (Published: April 2016) Citation: Kristian Åtland (2016) «Myndighetsutøver, ressursforvalter og livredder – den russiske kystvakten i støpeskjeen». Nordisk Østforum 30 [1] 38–54. http://dx.doi.org/10.17585/nof.v30.390

黄海中部近岸春夏季鱼卵、仔稚鱼群落结构特征

PDF HTML阅读 XML下载 导出引用 引用提醒 黄海中部近岸春夏季鱼卵、仔稚鱼群落结构特征 DOI: 10.5846/stxb201410091983 作者: 作者单位: 中国海洋大学水产学院,中国海洋大学水产学院,中国海洋大学水产学院,中国海洋大学水产学院,中国海洋大学水产学院,中国科学院海洋研究所海洋生态与环境科学重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 高等学校博士学科点专项科研基金项目(20120132130001);中央高校基本科研业务费专项资金项目(201262004);国家自然科学基金委-山东省联合基金项目(U1406403);海洋公益性行业科研专项经费项目(201305030) The community structure of ichthyoplankton in the central Yellow Sea in spring and summer Author: Affiliation: College of Fisheries,Ocean University of China,Qingdao-,College of Fisheries,Ocean University of China,Qingdao-,College of Fisheries,Ocean University of China,Qingdao-,College of Fisheries,Ocean University of China,Qingdao-,College of Fisheries,Ocean University of China,Qingdao-,Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences. Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:2013年4月下旬至7月上旬,采用浅水I型网垂直拖网的调查方式对黄海中部20m以浅海域(34°30'-35°30'N,119°20'-120°20'E)的鱼卵、仔稚鱼种类组成与数量分布进行了6个航次的综合调查。春夏季共采集鱼卵21种(未定种3种),共计2247粒,隶属于9科15属。仔稚鱼22种(未定种1种),共计286尾,隶属于13科17属。鱼卵优势种为日本鳀Engraulis japonicus、赤鼻棱鳀Thryssa kammalensis、江口小公鱼Stolephorus commersonnii、皮氏叫姑鱼Johnius belengerii和属Callionymus spp.。仔稚鱼优势种为大银鱼Protosalanx chinensis、白姑鱼Argyrosomus argentatus、日本鳀、赤鼻棱鳀和皮氏叫姑鱼。鱼卵丰度和分布与经度呈负相关、与SST呈正相关,但与其他环境因子如纬度、表层盐度(SSS)和水深等无显著相关性。仔稚鱼丰度和分布与上述环境因子均未表现出显著相关性。基于Bray-Curtis指数的聚类分析表明,鱼卵优势种包括集中分布于研究水域34°48'N以南海域(江口小公鱼、皮氏叫姑鱼和青鳞小沙丁Sardinella zunasi)、10m等深线以内(赤鼻棱鳀),以及北部水域(日本鳀和属)3种主要聚集类型;仔稚鱼优势种包括集中分布于34°48'N-35°12'N海域(赤鼻棱鳀和日本鳀)、连云港外海浅水区(白姑鱼、皮氏叫姑鱼和梭鱼Liza haematocheilus,以及南部水域(褐菖鲉Sebastiscus marmoratus和鲬Platycephalus indicus)3种主要聚集类型。研究结果揭示了黄海中部近岸海域鱼卵、仔稚鱼群落的时空分布格局动态,为科学认识环境变动下该海区渔业种群数量动态和资源变化提供了科学依据。 Abstract:Knowledge of the ecology of ichthyoplankton (eggs, larvae, and fry) is important for understanding the spawning ecology and the population dynamics of fishery species. In this study, a total of six fishery research cruises were conducted to investigate the community structure and ecology of ichthyoplankton in the central Yellow Sea (34°30'-35°30' N, 119°20'-120°20' E), one of the most concentrated spawning areas for fishery species in Chinese coastal waters, from late April to early July 2013. To collect ichthyoplankton, zooplankton nets (mouth diameter=50 cm, length=145 cm, and mesh size=0.505 mm) were vertically trawled in waters below the 20 m isobath line. The species composition, abundance, and distribution of the ichthyoplankton, and their relationships with environmental factors, were studied. A total of 2247 eggs and 286 larvae were collected during the research cruises. The eggs were identified as belonging to 18 species in 15 genera in 9 families; 3 species could not be identified. The eggs were dominated by Engraulis japonicus, Thryssa kammalensis, Stolephorus commersonii, Johnius belengerii, and Callionymus spp. The larvae were identified as belonging to 21 species in 17 genera in 13 families; only one species could not be identified. The dominant larval species included Protosalanx hyalocranius, Argyrosomus argentatus, E. japonicus, T. kammalensis, and J. belengerii. The abundance of the eggs was positively correlated with the sea surface temperature (SST) but was negatively correlated with the longitude (P < 0.05). In contrast, the abundance of the larvae did not show a significant correlation with any of the investigated environmental factors, such as longitude, latitude, SST, sea surface salinity (SSS), or water depth. Cluster analysis based on the Bray-Curtis similarity index identified three assemblages of eggs and larvae at the 35% and 12% similarity levels, respectively. The eggs were grouped into assemblages dominating the southern waters from 34°48'N (S. commersonii, J. belengerii, and Sardinella zunasi), the < 10 m isobath waters (T. kammalensis), and the northern waters (E. japonicas and Callionymus spp.). The larvae were grouped into assemblages that were mainly distributed in the 34°48'N-35°12'N waters (T. kammalensis and E. japonicus), the shallow waters off Lianyungang (A. argentatus, J. belengerii, and Liza haematocheilus), and the southern part of the study area (Sebastiscus marmoratus and Platycephalus indicus). The findings of this study clarified the spatial and temporal distribution patterns as well as the structure of the ichthyoplankton community in the central Yellow Sea, which may help to improve our understanding of the population dynamics of fishery species in these waters. 参考文献 相似文献 引证文献

Did the Indo-Pacific leptomedusa Lovenella assimilis (Browne, 1905) or Eucheilota menoni Kramp, 1959 invade northern European marine waters? Morphological and genetic approaches

Hydromedusae, morphologically resembling the Indo-Pacific leptomedusa Lovenella assimilis (Browne, 1905) (Cnidaria: Hydrozoa: Lovenellidae), are reported for the first time in both the eastern English Channel and the southern bight of the North Sea. Analyses of past zooplankton samples from a long-term monitoring program suggest that this non-indigenous species has been present in the eastern English Channel at least since 2007. Genetic analyses identified specimens as Eucheilota menoni based on nearly identical 18S ribosomal RNA gene, mitochondrial cytochrome oxydase subunit gene I (COI) sequences, and 16S Ribosomal RNA gene. Consequently, published morphological descriptions of L. assimilis and E. menoni were compared, and their species status is discussed with regard to morphological and genetic evidence. In conclusion we suggest synonymizing these 2 indistinguishable species.