The paranthurid isopod crustacean Paranthura nigropunctata (Lucas, 1846): first record from the Atlantic coast of Morocco

The littoral paranthurid isopod crustacean Paranthura nigropunctata (Lucas, 1846) is recorded for the first time from the littoral of El Jadida located on the Atlantic northwest coast of Morocco. Specimens were obtained from the invasive brown seaweed Sargassum muticum and the natives Bifurcaria bifurcata and Cystoseira tamariscifolia in January 2015. This new record further confirms a significant southward distribution of P. nigropunctata and contributes to the knowledge of the biogeography of this isopod. Heretofore, the species was only known from the western and eastern Mediterranean and some Atlantic coasts. The present finding is the first of the species from Moroccan Atlantic shores, and suggests that the species may also be present in other coastal localities from Morocco and Africa. Some data on morphology, ecology and spatial distribution of the species are provided.     

Population genetic studies of horse mackerel Trachurus trecae and Trachurus trachurus capensis off Angola

Genetic variability of the Kunene horse mackerel Trachurus trecae and the Cape horse mackerel Trachurus trachurus capensis was examined using starch gel electrophoresis of enzymatic proteins on individuals collected along the Angolan coast. Six polymorphic enzyme loci were found in both species. The idh-2* locus displayed differences between the two species, and several alleles at different loci exhibited different allele frequencies between the two species, indicating that they are genetically different. Significant differences found in the distribution of allele frequencies between Kunene horse mackerel from the Benguela region of Angola indicated that this species consist of more than one randomly mating population in Angolan waters.     

福建沿海鲸鲨时空分布初探及保护对策

搁浅、误捕和救助记录是研究野生动物分布和获取其基本生物学数据的重要来源,尤其是对那些缺少系统性野外调查的物种。本研究收集了福建沿海2006—2019年间鲸鲨（Rhincodon typus）的搁浅、误捕和救助记录,初步探讨福建沿海鲸鲨的时空分布情况,并提出相应的保护对策。共收集福建沿海鲸鲨搁浅、误捕和救助记录30例,包括搁浅10例、误捕18例和救助2例,其中福州鲸鲨记录大部分在平潭岛附近,这可能与平潭海域上升流带来的丰富生物资源有关;所有记录中有28例（93.3%）发生在6—10月,表明夏秋季可能是鲸鲨在福建沿海活动的高峰期。此外,有体长记录的22条鲸鲨中,17条（77.3%）为幼年个体,可能是因为幼年鲸鲨偏好在高生产力的近岸海域聚集以获取充足的食物,因此也更容易搁浅或被误捕。较多的误捕记录（60.0％）提示渔业活动对鲸鲨有较大威胁。因此,建议建立全省甚至全国性的鲸鲨搁浅误捕数据库,进一步严格和规范渔业管理,改进渔具以降低误捕鲸鲨的概率,加强对公众（特别是渔民）的宣传教育,以更好地保护这一濒危物种。     

Multi-annual investigation of the spatial distributions of juvenile and adult sole (Solea solea L.) in the Adriatic Sea (northern Mediterranean)

The common sole (Solea solea) is one of the most important demersal resources in the northern and central Adriatic Sea (GFCM GSA 17). Landings from this basin make up around 23% of the overall Mediterranean and Black Sea production. Despite the economic relevance of sole in the Adriatic Sea, and its inherent property of being shared among three countries (i.e. Italy, Slovenia and Croatia), studies on its spatial distribution are scarce and aged. Therefore, the aim of the present study was to assess the spatial distribution and investigate the dynamics of this species in the GSA 17. Samples of common sole were collected in the framework of yearly rapido trawl surveys (SoleMon), during late autumn, from 2005 to 2010, i.e. the spawning season of common sole in the Adriatic. Results highlighted that juveniles are mostly concentrated in shallow water (0–30 m depth) along the Italian coast and their spatial distribution persisted along the sampled years. By contrast adults were mainly distributed in the central/eastern part of the basin at depths > 30 m. As a result of the different spatial distributions, juveniles are exploited exclusively by Italian vessels, especially by beam trawlers (i.e. rapido trawl), while adults are caught by Croatian and Slovenian fishing fleets in their respective national waters and by the Italian fleet operating in international waters. These results, while shedding light on the common sole spatial ecology in the Adriatic, represent crucial information for the setting of international collaboration for a rational spatial-based management of the resource.     

中国东南沿海小头虫科(环节动物:多毛类)一新种

中蚓虫是小头虫科较为常见的属,中国海区的样品过去常被鉴定为加洲中蚓虫Mediomastus californiensis Hartman。本研究中,来自东南沿海四个不同海区的118条中蚓虫样品被鉴定为一个新的种类,在此给出具体描述。这个新种具有如下特征：（1）第1至9刚节表皮双环型,刚毛束位于体节中间位置,而后的刚节多环型,刚毛束位于体节后半部;（2）后腹区具有疣足突起;（3）前4个胸刚节仅具双羽型翅毛状刚毛,其它体节仅具巾钩刚毛;（4）胸区巾钩刚毛的柄长且直,巾长为宽的3至5倍;（5）腹区巾钩刚毛不同于胸区,较短且具收缩部;（6）甲基绿染色模式独特。这个研究表明了中国海区的中蚓虫可能被误鉴定为加洲中蚓虫,而这个新种M.chinensis sp.nov.在东南沿海广为分布。     

Phylogeographic study on the chub mackerel (Scomber japonicus) in the Northwestern Pacific indicates the late Pleistocene population isolation

In the present study, the population genetic structure and historical demography of the chub mackerel, Scomber japonicus, in the Northwestern Pacific were examined based on the full‐length sequences of the mitochondrial control region and cytochrome b gene. A total of 320 individuals was sampled from 11 localities along the coast of China and Japan from August 2011 to May 2013. Two main clades representing Chinese and Japanese populations, respectively, were detected, suggesting population isolation of S. japonicus during the late Pleistocene era. The Chinese clade was further divided into two small clades and the distribution of haplotypes were not related to sampling locality, which may be a signature of secondary contact following past division. Analyses of molecular variance and pairwise F_ST revealed significant genetic differentiation between the Chinese and Japanese populations, but a lack of genetic structure for the populations along the coast of China. Both neutrality tests and mismatch distribution analysis suggested that the populations along the coast of China experienced population expansion during the late Pleistocene. Historical events, biological characteristics and other extrinsic forces such as ocean currents may all be associated with the current phylogeographic pattern of S. japonicus in the Northwestern Pacific.     

Habitats and Characteristics of the Sea Urchins Lytechinus variegatus and Arbacia punctulata (Echinodermata) on the Florida Gulf-Coast Shelf

Abstract Lytechinus variegatus and Arbacia punctulata have been studied primarily in inshore, shallow‐water areas. However, they are abundant in deeper waters on the Florida gulf‐coast shelf and seem important components of the benthic communities there. Lytechinus variegatus occurs alone on sand bottoms and A. punctulata occurs alone on rubble bottoms in these deeper waters. The species also co‐occur there on ­heterogeneous bottoms, each in a distinct microhabitat with A. punctulata on rubble and L. variegatus on surrounding sand. Characteristics of the sea urchins in these different deeper‐water habitat types and at one nearshore site with a heterogeneous rubble‐sand bottom were compared. Over the 2‐year study, offshore individuals of both species had low gut and gonad indices and the maximum size of individuals did not change. This suggests food limitation and low production. Offshore, A. punctulata had a higher Aristotle's lantern index and lower gut and gonad indices in populations where it ­co‐occurred with L. variegatus compared to populations where it occurred alone. The ­Aristotle's lantern index of L. variegatus did not differ among the offshore sites. Neither species seemed food limited at the nearshore site. Although productivity is lower at the offshore sites, both species extend their distribution and reproduction potential by existing there.     

中国温带海域新发现较大面积(大于50ha)的海草床:Ⅰ黄河河口区罕见大面积日本鳗草海草床

日本鳗草(Zostera japonica)原是中国沿海潮间带较为常见的海草种类,近些年来随着生境的破坏其分布面积急遽下降,较大面积连续分布的海草床已经非常少见。2015年5月和8月,在山东黄河河口区发现了超过1000 ha几乎连续分布的日本鳗草海草床,与互花米草生境相邻,形成独特的生态景观。对日本鳗草生物量和种群补充等基本生物学指标也进行了调查。该发现极大丰富了中国海草数据库,并为日本鳗草的深入研究及保护提供了得天独厚的实验基地。     

Mesh selection studies on flatfish in relation to the Otago trawl fishery

Cod‐end mesh selection experiments were conducted on three species of flatfish (common or English sole Peltorhamphus novaezeelandiae, lemon sole Pelotretis flavilatus, and sand flounder Rhombosolea plebeia) trawled off the Otago coast. It is suggested that better yields would be obtained from stocks of these fish if the minimum cod‐end mesh size was increased from 10.2 cm (4 in.) to 11.4 cm (4.5 in.).     

South Africa's coastal-breeding white-breasted cormorants: population trends,breeding season and movements,and diet

White-breasted cormorants Phalacrocorax [carbo] lucidus breed around South Africa's coast and at inland localities. Along the coasts of the Northern, Western and Eastern Cape provinces, numbers breeding were similar during the periods 1977–1981 (1 116 pairs at 41 localities) and 2008–2012 (1 280 pairs at 41 localities). Along the coast of KwaZulu-Natal (not counted in 1977–1981), 197 pairs bred at nine localities in 2008–2012, when the overall number breeding around South Africa's coastline was about 1 477 pairs. Between the two study periods, numbers decreased in the Northern and Western Cape provinces following the loss of several breeding localities, but they increased in the Eastern Cape. In the Western Cape, however, numbers were stable east of Cape Agulhas and at nine well-monitored West Coast localities that were surveyed from 1978 to 2012. White-breasted cormorants breed throughout the year, with breeding at some localities more seasonal than at others and the timing of peaks in breeding varying at and between localities. In the vicinity of Saldanha Bay/Langebaan Lagoon (Western Cape), in Algoa Bay (Eastern Cape) and in northern KwaZulu-Natal, it is likely that birds moved between breeding localities in different years, although breeding often occurred at the same locality over several years. Human disturbance, presence of predators, competition for breeding space and occurrence of breeding by other waterbirds may influence movements between colonies. Securing sufficient good habitat at which white-breasted cormorants may breed will be important for conservation of the species. The species may breed at an age of 4 years, possibly younger. The bulk of their diet around South Africa's coast consists of inshore marine and estuarine fish species that are not intensively exploited by humans.     

Sexual traits plasticity of the potentially invasive limpet Bostrycapulus odites (Gastropoda: Calyptraeidae) within its natural distribution in South America

The slipper limpet Bostrycapulus odites has recently been reported as an introduced species on the Spanish Mediterranean coast. Another species in the family Calyptraeidae, Crepidula fornicata, is a problematic invasive species in the Northeast Atlantic, which makes the closely related Bostrycapulus introduction a matter of concern. Information on the biology of B. odites in its natural environment can facilitate predictions on where the species could find favourable conditions for settlement and expansion. Size and sex were recorded for individuals in four populations over 2600 km of the Southwestern Atlantic shoreline, in Argentina and Brazil, covering the whole native latitudinal range of this widely distributed species. Animals were collected by hand in the intertidal or by SCUBA in subtidal locations; specimens were examined to determine shell length, sex, and the presence and number of brooded egg capsules in females. Mean shell length for the whole population did not differ significantly among populations. However, this species experiences sequential hermaphroditism (protandrism), and the size at sexual maturity (minimum male size) increased significantly with latitude. The fecundity of females at all sites increased with size, and the number of brooded egg capsules as well as the average size of capsules was larger in bigger individual females; however, mean fecundity varied among sites independent of mean female body size. This limpet species modifies its reproductive traits with local conditions, and sexual characters develop earlier in more temperate localities.     

山东半岛近岸海域蟹类群落结构特征的研究

根据2014年8月和10月、2015年2月和5月使用单船底拖网进行的4个航次调查数据,对山东半岛近岸海区的莱州湾及渤海南部、山东半岛北部和山东半岛南部等3个海域蟹类种类组成、时空分布、优势种、群落结构稳定性等群落结构特征进行了研究。结果显示,4次调查共捕获蟹类20种,隶属于10科17属,其中日本蟳（Charybdis japonica）和三疣梭子蟹（Portunus trituberculatus）是主要经济种类,其余均为小型饵料型蟹类;海区内主要的优势种为双斑蟳（Charybdis bimaculata）、日本蟳（Charybdis japonica）和三疣梭子蟹（Portunus trituberculatus）,3个海域优势种季节更替均十分明显;莱州湾及渤海南部和山东半岛南部2个海域生物量季节变化明显,春季较低,在夏季达到峰值,夏季到冬季呈降低趋势,山东半岛北部海域生物量季节变化不明显。3个海域蟹类群落物种多样性指数（H'）、丰富度指数（D）及均匀度指数（J'）均处于较低水平,并有一定的季节变化;水深、水温和盐度是影响蟹类群落结构的重要因子,渤莱沿岸流、黄海暖流和黄海冷水团通过影响海域内水温与盐度影响蟹类群落结构。研究表明山东半岛近岸海区蟹类以小型饵料型蟹类为主,蟹类多样性水平较低,优势种更替明显,群落季节更替指数较高,季节间迁移频繁,蟹类群落不稳定。     

Distribution,behaviour and photo-identification of Atlantic humpback dolphins Sousa teuszii off Flamingos,Angola

Atlantic humpback dolphins Sousa teuszii are a priority for research due to their restricted geographic range, narrow ecological niche and the paucity of existing information. The distribution and behaviour of S. teuszii off Flamingos, southern Angola, was investigated during summer and winter 2008 using boat- and shore-based surveys. In all, 71 S. teuszii sightings were recorded, ranging from one to eight animals. Sousa teuszii inhabited shallow, nearshore waters throughout the region, with the exception of southern areas adjacent to fishing villages. Small bays, sheltered waters behind reef-breaks and areas off dry river mouths were used for foraging/feeding behaviour, whereas most travelling occurred along exposed coast. Ten individual S. teuszii were photo-identified. Multiple resightings (and absence of unmarked animals) indicate that all individuals present at the time of the surveys were photocaptured, exhibited high site fidelity and had year-round occurrence. Association indices of 0.77-1.0 indicated strong social affiliation between eight individuals, particularly in winter. Off Flamingos, S. teuszii occurs in small numbers and exhibits high site fidelity to a relatively small stretch of nearshore habitat, making the species vulnerable to local extirpation. Wider-scale surveys and development of a management plan are crucial to ensuring the long-term conservation of S. teuszii off Flamingos.     

Factors Affecting the Wintering Habitat of Major Fishery Resources in Southwestern Korean Waters

We investigated the temperature and salinity effects on the major fish species in the wintering grounds based on trawl surveys and oceanographic observations in the southwestern waters of Korea during March-early April in 2002-2003. The influence area of warm Kuroshio water was limited to the southwestern area of Korea in 2003 with a range of 7.7-16.3°C, 32.54-34.70 of salinity, wider than that of 2002. The number of fish species and density of major fish species in 2003 were higher than in 2002. Geographical estimation showed high proportions of species number and catches in the areas around Jeju Islands, southwestern waters and the southeastern coast of Korea. Five species; silver pomfret (Pampus echinogaster), hairtail (Trichiurus lepturus), anchovy (Engraulis japonicus), small yellow croaker (Larimichthys polyactis) and yellow goosefish (Lophius litulon) were most abundant, composing above 60% of the total catch in 2002 and 2003. More than 50% of catch in the major fish species were mostly distributed in the range of 9.5-11.0°C of temperature and 33.1-33.9 of salinity. Non-parametric estimation for the major species showed the 1st mode around 10°C and the 2nd mode at 8-9°C in 2002 and 11-14°C in 2003. A m o n g major fish species, hairtail was principally composed of juveniles, and larger individuals were caught in southeastern waters. These results are considered to be helpful for the areabased fishery management strategy for the wintering grounds of the Yellow Sea and coastal waters of Korea.     

Influence of environmental disturbances and reproductive strategy on genetic diversity and differentiation of Zostera marina populations on the southern coast of Korea

The genetic diversity and differentiation of four Zostera marina populations along the southern coast of Korea were estimated using random amplified polymorphic DNA (RAPD) markers to determine the effects of natural and anthropogenic stresses and reproductive strategy on within‐population genetic diversity. The mean number of alleles and gene diversities, indicating population genetic diversity, was highest in the Z. marina population that was exposed to repeated environmental disturbances, and lowest in the most undisturbed population. The higher genetic diversity in the disturbed population was associated with a higher contribution of sexual reproduction to population persistence. This suggests that both the level of disturbances and the reproductive strategy for population persistence contributed significantly to population genetic diversity at the study sites. According to the analysis of molecular variance (AMOVA), 76% genetic variation was attributable to differences among individuals within populations. The observed genetic differentiation (F_ST = 0.241) among Z. marina populations at the study sites appeared to result from reduced meadow size, increased genetic drift, and a high incidence of asexual reproduction. Increased population genetic diversity can enhance resistance and resilience to environmental disturbances; thus, this investigation of seagrass population genetics provides valuable new insights for the conservation, management, and restoration of seagrass habitats.     

The distribution of spiny lobsters in New Zealand waters (Crustacea: Decapoda: Palinuridae)

Two species of spiny lobsters (marine crayfish) inhabit New Zealand waters: Jasus edwardsii (Hutton, 1875), and J verreauxi (H. Milne Edwards, 1851). J edwardsii, the more common species, is present along most rocky coastlines in New Zealand, but is more abundant in the south‐west of the South Island and at the Chatham Islands. The species apparently reaches its northern limit of distribution at the Three Kings Islands (34°S) and its southern limit at the Auckland Islands (51°S).

J. verreauxi, the less common species, is almost solely restricted in New Zealand waters to the north‐east coast of the North Island. It is uncommon in the west and the south of the North Island, and is rare in the South Island. J. verreauxi apparently reaches its northern limit of distribution at the Kermadec Islands (31°S), and its southern limit near Bluff (47°S) in the South Island.     

中国海草资源分布现状、退化原因与保护对策

海草床是三大典型的近海海洋生态系统之一,具有极高的生态服务功能。然而,截至2015年我国近海海草资源分布现状尚不明晰,严重制约了我国海草床保护与修复工作的开展。2015～2021年,笔者通过实地调查,借助船只走航、声呐探测、遥感等技术手段,重点对我国近海海草资源的分布面积、种类及主要威胁进行了全面普查,并据此提出我国海草床管理与可持续利用对策。结果表明,我国近海海域海草床面积共为26 495.69hm²,可划分为:温带海域海草分布区和热带-亚热带海域海草分布区;我国现有海草4科9属16种。其中,温带海域海草床面积为17 095.01 hm2,主要分布在辽宁、河北、天津和山东沿海,分布有2科3属5种,以鳗草(Zosteramarina)和日本鳗草(Z.japonica)为优势种,其中唐山乐亭-曹妃甸海草床面积达9 025.56 hm2,是我国面积最大的海草床;热带-亚热带海域海草床面积为9 400.68 hm2,主要分布在福建、广东、广西和海南沿海,分布有4科8属12种,以泰来草(Thalassia hemprichii)、海菖蒲(Enhalus acoroides...     

Temporal dynamics of subtidal Zostera marina and intertidal Zostera japonica on the southern coast of Korea

The temporal dynamics of two seagrass species, Zostera marina and Z. japonica, were monitored monthly in Dadae Bay, Geoje Island, on the southern coast of Korea. Plant morphological characteristics, shoot density, biomass, leaf production, reproductive effort, and environmental characteristics were monitored from July 2001 to July 2002. Zostera japonica occurred in the intertidal zone and Z. marina occurred in the subtidal zone from 0.5 to 2.5 m below the mean low water level. Shoots and rhizomes were significantly larger in Z. marina than in Z. japonica, whereas the shoot density was greater in Z. japonica than in Z. marina. Despite differences in morphology and shoot density, biomass did not differ significantly between the species. Reproduction occurred from April to June in Z. marina and from May to July in Z. japonica. The proportion of reproductive shoots was approximately three times higher in Z. marina than in Z. japonica. Seasonal variation in the biomass of Z. japonica was caused by changes in both shoot size and density, whereas that of Z. marina was mainly caused by changes in shoot length. Leaf production in Z. marina and Z. japonica showed clear seasonal variation, and leaf production in Z. marina (2.6 ± 0.2 g DW·m⁻²·day⁻¹) was higher than that in Z. japonica (1.7 ± 0.2 g DW·m⁻²·day⁻¹). The mean plastochrone interval was not significantly different between the two species, whereas the leaf lifetime of Z. marina was longer (69 ± 7.8 days) than that of Z. japonica (59 ± 8.3 days). Our results indicated that seasonal leaf growth patterns in Z. japonica are correlated with irradiance and temperature, whereas those in Z. marina respond most to irradiance. Seasonal changes in irradiance appeared to control the temporal variation in above‐ground biomass in both species.     

Use of submerged aquatic vegetation as habitat by young-of-the-year epibenthic fishes in shallow Maine nearshore waters

Epibenthic fishes were collected with daytime beam trawl tows (n = 1713) in three shallow (<10 m) habitats of submerged aquatic vegetation (SAV), Zostera marina (eelgrass), Laminaria longicruris (kelp), Phyllophora sp. (algae), and unvegetated sandy/mud areas. We divided the Maine coast into three broad zones based upon geological features and sampled over five consecutive years; during April–November 2000 in the mid coast, in 2001 and 2002 along the south coast and in 2003 and 2004 along the eastern Maine coast. We quantified habitat use by eight economically important fish species (Gadus morhua, Microgadus tomcod, Pollachius virens, Urophycis chuss, Urophycis tenuis, Osmerus mordax, Tautogolabrus adspersus, and Pseudopleuronectes americanus) and 10 other common epibenthic species (n = 18 571). We identified the physical and biological variables most important in discriminating between habitats with and without individual fish species. Logistic regression models based on nearshore habitat characteristics were developed to predict the distribution of these species along the three zones representing broad geological regions of the Maine coast. Logistic regression models correctly classified individual fish species 58.7–97.1% of the time based on the temporal and physical habitat variables (month, temperature, salinity, and depth) and the presence–absence of submerged aquatic vegetation (Zostera, Laminaria, or Phyllophora). Overall fish presence and economically important fish presence were correctly classified 61.1–79.8% and 66.0–73.6% of the time, respectively. The Maine shallow water fish community was composed primarily of young-of-the-year and juvenile fishes with all habitats functioning as facultative nursery areas. Presence of most fish species was positively associated with Zostera, Laminaria, and to a lesser extent, Phyllophora. This study provides direct evidence of shallow waters of the Gulf of Maine as critical facultative nursery habitat for juvenile G. morhua, M. tomcod, P. virens, U. tenuis, U. chuss, T. adspersus, O. mordax and P. americanus, and many ecologically important species.