烟台多棘海盘车种群的个体大小分布及生殖周期

为了解烟台多棘海盘车种群个体大小分布及繁殖特征,自2010年5月至12月及2015年3月到5月,在烟台近海对该种群分别进行逐月采样调查。利用性腺指数(GI)和幽门盲囊指数(PCI)以及解剖组织学方法预测其产卵周期。结果表明：在所有的采样月份中,体长大于143mm的个体与体长小于42mm的个体在种群中均同时存在;在5-8月期间,种群结构特征以体长小于55mm的个体为主。同时该海域不同站点的采样月份中均有小个体存在,说明种群的产卵周期存在延后现象或者由于食物短缺造成了海星生长缓慢。腕长可以很好的用来衡量还行身体湿重。性腺在2010年5月-9月发育相对缓慢但在十月份迅速到达峰值20.95,之后明显下降,表明其产卵期从10月份持续至11月份。2015年3月-5月也发现了同样的现象,表明该种群自3月-5月存在另一个产卵期,且通过对卵的组织学分析也进一步证实该产卵期的存在。性腺指数和幽门盲囊指数呈负相关关系。由于食物来源短缺,烟台近海海星种群的繁殖特征极有可能受到当地近海扇贝养殖的影响。     

Geographical implications of seasonal reproduction in the bat star Asterina stellifera

The reproductive cycle and environmental cues that regulate gonad production in Asterina stellifera were studied from April 2009 to April 2011 in a rocky subtidal habitat at the southernmost limit of its distribution (Mar del Plata, Argentina). The geographic variation in reproductive traits between latitudinal range limits was analyzed. The gonadal and pyloric caeca weight varied with sea star size and time in both sexes. Despite a previous study which suggested the absence of recruitment in a 4 year period, our data of the same period demonstrated that spawning happens from early spring to early summer. The gonad and pyloric caeca weight did not show an inverse relationship, this suggested that there is no dependence on energy transfer between the organs and that the bat star presented a good nutritional state. Seawater temperature appears to be the variable explaining gonad proliferation at the range limits of A. stellifera distribution. Furthermore, differences in sex ratio, oocyte production, oogenesis duration and capability of energy transformation into ova were found between range limits.     

扁玉螺的生殖腺组织学和生殖周期

采用组织切片和HE染色法,对烟台沿海扁玉螺的生殖腺发育过程进行了观察.根据性腺发育的组织学特征,将扁玉螺生殖腺发育过程分为增殖期、生长期、成熟期、排放期和休止期5个时期;扁玉螺在烟台沿海每年一个生殖周期,繁殖季节为5月上旬至8月中旬,繁殖盛期为6月上旬至7月下旬.上述研究结果探明了扁玉螺的生殖腺发育规律,丰富了扁玉螺的繁殖生物学资料,对开发利用扁玉螺有着积极的意义.     

Reproductive cycle and gonadial changes in the New Zealand rock oyster Crassostrea glomerata

The annual reproductive cycle and the cyclical changes in the gonad of the New Zealand rock oyster, Crassostrea glomerata (Gould, 1850), during the breeding period of 1970–71 and 1971–72 have been described. The gonad passes through an intermediate phase, after a post‐spawning period, when sex is indeterminate. Gametogenesis begins in July and August, but follicles ripen mostly during the spring months of October and November. Maximum development is seen in November, and nearly all oysters are in spawning condition in December and January. Major spawning takes place in January or February depending upon water temperature, and spawning continues until the end of March. Larvae may be found in the‐ plankton until late in the season, to the end of April or even May. Following spawning, gonadial regression sets in, with leucocyte infiltration and phagocytosis of residual gonial cells. A greater percentage of oysters more than 1 y old are females. The majority of oysters of age 1 y and below are males.     

Hydrographical characteristics and oxygen isotopic signatures of water in a coastal environment (Mangalore) along the southeastern Arabian Sea

Coastal marine environments are important links between the continents and the open ocean. The coast off Mangalore forms part of the upwelling zone along the southeastern Arabian Sea. The temperature, salinity, density, dissolved oxygen and stable oxygen isotope ratio (δ¹⁸O) of surface waters as well as those of bottom waters off coastal Mangalore were studied every month from October 2010 to May 2011. The coastal waters were stratified in October and November due to precipitation and runoff. The region was characterised by upwelled bottom waters in October, whereas the region exhibited a temperature inversion in November. The surface and bottom waters presented almost uniform properties from December until April. The coastal waters were observed to be most dense in January and May. Comparatively cold and poorly oxygenated bottom waters during the May sampling indicated the onset of upwelling along the region. δ¹⁸O of the coastal waters successfully documented the observed variations in the hydrographical characteristics of the Mangalore coast during the monthly sampling period. We also noted that the monthly variability in the properties of the coastal waters of Mangalore was related to the hydrographical characteristics of the adjacent open ocean inferred from satellite-derived surface winds, sea surface height anomaly data and sea surface temperatures.     

Environmental drivers of small scale spatial variation in the reproductive schedule of a commercially important bivalve mollusc

Understanding variability in reproductive schedules is essential to the management of recruitment limited fisheries such as that of Pecten maximus. Small scale (<5 km) variation in gonad condition and the onset of spawning of P. maximus were found among commercial scallop grounds in Isle of Man waters. Environmental and fishing drivers of these spatial patterns were investigated using a generalised additive model. Rate of change in temperature over the month prior to sampling was identified as the short term driver of gonad weight associated with the autumn spawning event. Long term drivers were average annual chlorophyll a concentration, scallop density, stratification index and shell size. The model explained 42.8% of deviance in gonad weight. Within site variation in gonad condition was high, indicating a “bet hedging” reproductive strategy which may decrease the chance of fertilisation especially at low densities. Therefore, areas protected from fishing, where scallop densities can increase may help buffer against reproductive failure. An increase in shell length from 100 mm to 110 mm equated to an increase of approximately 20% in gonad weight. Protecting scallops from fishing mortality until 110 mm (age four) compared to 100 mm (age three) may lead to an overall increase in lifetime reproductive output by a factor of 3.4.     

Developmental duration and morphology of the sea star asterias amurensis, in tongyeong, Korea

The process of embryogenesis and larval development of the asteroid sea star Asterias amurensis (Lütken) was observed, with special attention paid to morphological change and larval duration. In reproductive season, mature sea stars were collected under floating net cages, located in Tongyeong, southern Korea. The mature eggs are 138 μm in average diameter, semi-translucent and orange in color, sperms in good condition appear light cream to white-gray in color. Embryos develop through the holoblastic equal cleavage stage and a wrinkled blastula stage that lasts about 9 hours after fertilization. Gastrulae bearing an expanded archenteron hatch from the fertilization envelope 22 hours after fertilization. At the end of gastrulation, rudiments of the left and right coelom are formed. By day 2, larvae possess complete alimentary canal and begin to feed. At this stage, the larva is called early bipinnaria. In 6day-old larvae, the pre- and post- oral ciliated bands form complete circuits and the bipinnarial processes start to develop. By day 12, the lateral and anterior projection of the larval wall processes along the ciliated bands begins to thicken and curl, and the ciliated bands become more prominent. By day 32, early brachiolaria are presented with three pairs of brachiolar arms. Advanced brachiolaria with a well-developed brachiolar complex (three pairs of brachia and central adhesive disc) occur 6 weeks after fertilization. In the field, spawning of the sea star was observed in April to May, settlement form larvae and just settlements seem to occur from June to July, and early juveniles occur from August to September. Although we had not described the end of brachiolaria stage, it can be tentatively estimated that the duration of the pelagic stage of A. amurensis is 40 to 50 days.     

海湾扇贝南移后繁殖期的变动

本文根据海湾扇贝的肥满度、肉柱百分数、性腺指数及消化脓指数等指标的周年变化，并结合性腺的组织切片来确定其繁殖期。结果表明，海湾扇贝南移后的繁殖期是从每年的10月下旬开始的，直到翌年5月下旬，其中4月为繁殖盛期。繁殖期间，扇贝的性腺分批成熟，分批排放，并有消退与恢复的现象。同时，海湾扇贝引进中国北方海区并南移福建后，其繁殖规律与原产地（美国大西洋沿岸）的繁殖期有很大的不同。     

中国沿海真鲷种群鉴别研究

对1990-1998年期间取样于中国沿海5个不同海区的真鲷(Pagrosomus major Temminck et Schlegel)样品的23项形态性状进行测量,并应用差异系数、均数差异显著性、方差分析和判别函数分析等数理统计学方法对性状特征的差异进行比较,结合产卵场、分布洄游习性以及海洋环境条件进行综合分析,存此基础上对上述海区的真鲷种群分群问题进行了探讨。结果表明．中国沿海真鲷可分为4个不同地方种群．即黄渤海地方种群、东海地方种群、闽南-南海地方种群和北部湾地方种群。文中还讨论了真鲷种质资源保护问题。     

The timing and reproductive output of the commercial sea cucumber Holothuria scabra on the Kenyan coast

The sea cucumber Holothuria scabra is a widely distributed and economically important species that has been harvested in Kenya for decades. No previous studies have been carried out on the reproduction of this species in Kenya. Standard gonad index methods were used to analyze reproductive patterns of individuals collected monthly in 1998–1999, 2000–2001 and 2006–2007. Morphological characteristics, gonad tubule lengths and fecundity were also measured. Mean monthly gonad indices were significantly correlated between males and females indicating synchronous gonad development between the sexes. Gonad indices showed a biannual pattern that was consistent in all three years with a minor spawning event occurring between August and September and a major spawning event between November and December. The pattern of gonad growth showed significant variability between years and between months. Temporal changes in gonad growth correlated significantly with gonad tubule length and absolute fecundity. Monthly gonad indices also correlated significantly with monthly measurements of air temperature and light suggesting a possible role for both factors in timing gametogenesis and spawning. There was a shift in sex ratio from unity in the 1998–1999 and 2000–2001 samples to significantly more males in the 2006–2007 samples, as well as a significant reduction in mean sizes (body wall weight) and reproductive output (gonad index) which suggests that the reproductive success of this species is potentially negatively affected by fishing.     

Measuring reproductive condition in the Greenshell™ mussel Perna canaliculus

The annual reproductive cycle of Perna canaliculus (Gmelin) was investigated for 1 year by collecting monthly gonad samples from an intertidal population. Gonads of 50 animals were dissected and photographically recorded on video before being fixed for histological sectioning. The histological gonad sections were examined both qualitatively, using a classification and scoring system (S) and quantitatively, using image analysis technology. The quantitative measures used were the proportion of: (1) sections comprising follicles (FC); (2) sections comprising gametes (GC); and (3) the proportion of follicles comprising gametes (G/F). Significant consecutive monthly changes in the qualitative and quantitative measures indicated major spawning events. Gametogenesis occurred during winter with a spawning in August‐September. Gonad condition remained low during the spring and early summer until a development period between January and March. A second major spawning event occurred between March and April. There was a high degree of synchrony in reproductive status observed between the sexes. When comparing the four measurement methods using the f statistic as an index of power the GC measure was found to be the most reliable. A gonad visual grading system was developed for rapid assessment of gonad reproductive status and tested. Visual grades of pre‐recorded gonad samples were compared to the histological measures. Increasing visual grade correlated strongly with increases in all of the histological measurements.

The visual grading was a good predictor of the spawning activity of female P. canaliculus.     

欧氏六线鱼Hexagrammos otakii Jordan & Starks性腺发育的周年变化研究

根据对青岛附近水域欧氏六线鱼（已达性成熟年龄）性腺周年宏观和组织学观察，性腺发育可分为：①重复发育Ⅱ期；②开始成熟期；③接近成熟期；④临产期或产卵期；⑤产后期。按性腺指数变化并结合性腺组织切片确定，欧氏六线鱼性腺发育在青岛海区一年一个周期，繁殖期在１０月下旬至１２月，繁殖盛期是１１月下旬至１２月中旬。     

山东半岛东部近海海水溶解氧时空变化

山东半岛沿岸海域陆海相互作用强烈,有着复杂水动力环境的同时也是我国重要的渔业资源区和水产养殖区,针对其DO时空变化特征及影响机制的研究具有重要意义。本文基于2015—2017年期间的监测数据,研究了山东半岛东部近海海水溶解氧的时空变化特征,并结合实测的温度、盐度、pH数据探究其影响机制。结果表明：表、底层溶解氧的空间分布形态基本一致,水平上呈现出北高南低、外海高近岸低、湾内低于湾外的块状分布特点,垂向上表层高于底层。在监测期间内,溶解氧的季节变化规律为春季最高,夏季最低,具体表现为3月>5月>10月>8月,乳山湾等海湾处的季节波动较大;表底层溶解氧的年际变化略有不同,但均趋于稳定,靖海湾和五垒岛湾近海溶解氧的年际变化显著。表观耗氧量在整个研究阶段的均值为–0.33 mg/L,呈现出基本平衡状态,但乳山湾沿岸海域受到陆源输入有机物的显著影响,贫氧状况频发。监测期间,溶解氧与海水温度呈显著负相关,两者相关系数高达–0.95,其中成山头至石岛海域的溶解氧浓度高值区与当地的低温海水相对应;盐度对溶解氧的影响则相对较弱;有机污染物的聚集常造成乳山湾近岸海域的pH异常,其大量耗氧是导致当地为溶解氧浓度低值区的重要原因。     

Bioaccumulation and biomarkers in the sea star Asterias rubens (Echinodermata: Asteroidea): a North Sea field study

During two North Sea field trips in March 1995 and September 1996 sea stars, Asterias rubens, were collected at various stations along pollution gradients in order to study the relation between biochemical markers and levels of accumulated contaminants. Biomarkers measured were: cytochrome P450 level, benzo[a]pyrene hydroxylase (BPH) activity, acetylcholinesterase (AChE) activity and DNA integrity. Accumulation levels of heavy metals, polychlorinated biphenyls, organochlorine pesticides and polycyclic aromatic hydrocarbons (PAHs) in the pyloric caeca of sea stars indicate different pollution gradients, influenced by rivers in The Netherlands, UK and Germany. For some contaminants, especially PAHs, relatively high levels were found in the central part of the North Sea (Dogger Bank). On the basis of multivariate statistics, stations near the mouth of the Elbe and the Rhine/Meuse were shown to have different patterns of biomarker responses. Sea stars from stations in coastal zones showed relatively high levels of cytochrome P450 and 'P418', another haemoprotein that is present in most marine invertebrates. The station nearest to the Elbe Estuary showed the lowest BPH and AChE activity. DNA integrity was lower especially in stations near the Dutch coast and in a station near the Tees/Tyne estuaries. Using these biomarkers as early warning signals of exposure and/or adverse effects, this type of monitoring can be used also in the future to study the spatial and temporal trends in the quality of coastal waters.     

Reproductive resilience of ice‐dependent Antarctic silverfish in a rapidly changing system along the Western Antarctic Peninsula

The Western Antarctic Peninsula (wAP) is globally one of the systems most heavily impacted by climate change, notably steep declines in sea ice extent. In forage species, reproductive resilience to change is particularly important because population fluctuations are rapidly communicated through the system via trophic interactions. The reproductive traits of the ice‐dependent forage species Antarctic silverfish (Pleuragramma antarctica) from different areas along the wAP and at the tip of the Antarctic Peninsula were investigated through macroscopic and histological analyses of gonads, with the aim to assess its reproductive potential and to test for spatial differences in fecundity and spawning season. Fish samples were collected in late summer off Charcot Island, in Marguerite Bay and off Joinville Island; no fish were caught in the central wAP. Samples from Charcot Island and Marguerite Bay consisted of adults in developing gonad stage, whereas those from Joinville consisted almost exclusively of juveniles. Mean GSI was relatively low (2–3%) and similar in both sexes, as specimens were still far from being actively reproducing. Developing females exhibited two discrete, though partially overlapping modes of oocytes of different size, with vitellogenic oocytes measuring 0.5–1.0 mm. Absolute and relative fecundity ranged between 3000 and 12,000 eggs per female and between 80 and 190 eggs·g^?1, with a strong relationship between absolute fecundity and body size. These results were consistent with a single population at Charcot Island and Marguerite Bay and indicated substantial reproductive potential, which may mitigate population isolation and reductions in habitat availability but cannot ultimately offset catastrophic loss of spawning habitat linked to sea‐ice retreat.     

福建北部海域海地瓜（Acaudina molpadioides）的性腺发育研究

海地瓜（Acaudina molpadioides）是一种低值海参,本研究运用组织学和形态学方法对福建北部海域海地瓜的性腺发育特征及其周年变化进行了研究,并进一步探究了性别比、生殖周期、精卵排放类型、繁殖季节等繁殖生物学相关内容。结果表明,雌、雄海地瓜的性腺发育均可划分为休止期 (I)、发育早期 (II)、增长期 (III)、成熟期 (IV)、部分排放期 (V) 和排空期 (VI),雌、雄性腺发育程度基本同步。海地瓜性腺发育有明显的周年变化规律:大多数海地瓜在5月性成熟后开始陆续排放配子,配子排放过程中伴随着生殖管的自体破坏然后重生,即性腺开始新一轮发育,新的生殖细胞在11月开始生成并逐步发育直至翌年5月成熟。海地瓜性别比接近1∶1,生殖周期为1年,繁殖期为5?8月（夏季）,属于多次排精卵类型。     

Spatial distribution of Illex argentinus in San Matias Gulf (Northern Patagonia,Argentina) in relation to environmental variables: A contribution to the new interpretation of the population structuring

Traditionally, it was assumed that major spawning activity of Illex argentinus occurs in discrete pulses along the outer-shelf/slope off Argentina/southern Brazil during late-fall/winter and that early life stages develop near the Brazil–Malvinas Confluence (BMC). However, a novel hypothesis of the population structuring of the species was proposed that states that coastal waters may be important as spawning and feeding grounds. Here, we analyzed the spatial distribution of Illex argentinus inside San Matias Gulf based on the position of the CPUE of jiggers in order to improve the knowledge of the population structuring in coastal regions. Squids were mainly concentrated on the northern region of the gulf where favorable oceanographic conditions (e.g. water stratification, chlorophyll-a concentration peaks) to feeding and spawning are present. These results provided empirical evidences that individuals of I. argentinus use Argentinean coastal waters, particularly San Matias Gulf, as permanent feeding and spawning grounds which supports the new hypothesis.     

Changes in the population structure of Calanus sinicus during summer–autumn in the southern Yellow Sea

Calanus sinicus is a calanoid copepod widely distributed in coastal waters of China and Japan, and oversummering strategies may have major impacts on their population dynamics which in turn affect local marine food web structure. The abundance, stage composition, and sex composition of the planktonic copepod C. sinicus were studied from August to October 2002 in the southern Yellow Sea to understand how its population recovers from the over-summering state. Results showed that C. sinicus had low reproduction in August due to high temperature, except in waters near the Cheju Island with rich food and moderate bottom temperature, but the reproduction rates here decreased in September–October as food availability declined. When temperature dropped in September–October, C. sinicus actively propagated in coastal shallow waters. However, reproduction rates of C. sinicus individuals inhabiting the Yellow Sea Cold Water Mass(YSCWM) remained low during the three months of the study. The percentage of C. sinicus females was high during the reproductive period, which suggests that the sex composition of adult C. sinicus may reflect whether or not the population is in the reproductive mode.Numerous fifth copepodite stage(CV) C. sinicus aggregated in the YSCWM in a suspended developmental stage during the three months of this study, and they potentially served as the parental individuals for population development when conditions became optimal for reproduction later in the year.     

山东田横岛海域长牡蛎性腺发育及生化成分周年变化

为了阐明青岛近海长牡蛎(Crassostrea gigas)性腺发育周期及生化成分周年变化,于2019年4月—2020年3月,对青岛田横岛海区长牡蛎的性腺发育周期、生化成分(糖原、脂肪、蛋白质)的周年变化与环境因子(温度、盐度、叶绿素a)关系进行研究。研究显示,调查区长牡蛎性腺发育周期分为两个阶段:休止期(10—12月)和配子发生期(1—9月)。少部分长牡蛎配子发生于温度较低的1月(5.4℃),随着温度升高配子逐渐发育成熟,在6月温度较高(20℃)和叶绿素a浓度较大(1.67μg·L^-1)情况下,配子进入排放期。在配子发生期间,随着配子的成熟,条件指数和卵径在5月达到最大值,在配子排放后降低。生化成分含量为:在冬末春初浮游植物繁殖期间糖原含量储存在长牡蛎各组织中,随着性腺发育,各组织的糖原含量逐渐下降,为配子发育提供能量,这表明贮藏在各组织的糖原是配子发生期间的主要能源物质;性腺-内脏团的脂肪和蛋白质含量随着卵径增加呈上升趋势,产卵后其含量显著下降,表明脂肪和蛋白质与配子发育密切相关。研究结果表明,田横岛海域长牡蛎配子的发育方式为保守种模式。     

Reproductive biology of the leatherjacket,Meuschenia scaber (Monacanthidae) (Forster 1801) in the Hauraki Gulf,New Zealand

The leatherjacket Meuschenia scaber is widely distributed in Australasian waters, and is a valued bycatch of inshore bottom trawl fisheries although little is known of its life history. Here, we describe the reproductive biology of the species based on 651 leatherjackets sampled in the Hauraki Gulf, New Zealand, between July 2014 and March 2016. The maximum total length (L_T) recorded for females and males were 320 and 315?mm, respectively, with both sexes present in all size classes. Monthly analysis of gonad condition revealed a clear spawning season from late austral winter to early summer (August–December), and histological analysis of the ovaries revealed that M. scaber is an indeterminate serial spawning gonochorist. The estimated sizes at sexual maturity (L₅₀) for females (189.9?mm L_T) and males (188.4?mm L_T) did not differ significantly. Relatively small testes, sexual dimorphism and underwater observation of nesting suggest that M. scaber is a paired spawner.