Identification and Expression Profile of a Neuropeptide LFRFamide-Like Gene During Different Stages of Gonadal Development in the Cephalopod Sepia pharaonis

Neuropeptides are widely distributed in vertebrates and invertebrates,regulating a variety of physiological activities in the organisms,such as metabolism,feeding and reproduction.In this study,to explore the function of neuropeptide LFRFamide in Sepia pharaonis,the full-length cDNA of LFRFamide-like gene(named SpLFRFL,MG869822.1)was identified with rapid amplification of cDNA ends(RACE)method.The sequence of SpLFRFL was 860 bp in length and encoded 188 amino acids containing 4 different mature peptides:1 copy of PHTPFRFamide,NSLFRFamide,TIFRFamide,and 3 copies of GNLFRFamide.Multiple alignment and phylogenetic analysis results showed that SpLFRFL shared high identity with LFRFamides of Sepia officinalis and Sepiella japonica and had the closest relationship with them.Through quantitative Real-time PCR(qRT-PCR),it was found that the SpLFRFL gene was highly expressed in the optic lobe and brain at three different stages during gonad development in both genders.Moreover,the four mature peptides at a concentration of 0.01μmol L^(−1) could inhibit the protein synthesis in the Chinese hamster ovary cell strain-K1(CHOK1)induced by SpGnRH.These data suggest that SpLFRFL might be involved in the development and reproduction of S.pharaonis.The results can contribute to future studies on neuropeptide evolution and function and benefit the cuttlefish farming.

Cephalopods Classification Using Fine Tuned Lightweight Transfer Learning Models

Cephalopods identification is a formidable task that involves hand inspection and close observation by a malacologist.Manual observation and iden-tification take time and are always contingent on the involvement of experts.A system is proposed to alleviate this challenge that uses transfer learning techni-ques to classify the cephalopods automatically.In the proposed method,only the Lightweight pre-trained networks are chosen to enable IoT in the task of cephalopod recognition.First,the efficiency of the chosen models is determined by evaluating their performance and comparing thefindings.Second,the models arefine-tuned by adding dense layers and tweaking hyperparameters to improve the classification of accuracy.The models also employ a well-tuned Rectified Adam optimizer to increase the accuracy rates.Third,Adam with Gradient Cen-tralisation(RAdamGC)is proposed and used infine-tuned models to reduce the training time.The framework enables an Internet of Things(IoT)or embedded device to perform the classification tasks by embedding a suitable lightweight pre-trained network.Thefine-tuned models,MobileNetV2,InceptionV3,and NASNet Mobile have achieved a classification accuracy of 89.74%,87.12%,and 89.74%,respectively.Thefindings have indicated that thefine-tuned models can classify different kinds of cephalopods.The results have also demonstrated that there is a significant reduction in the training time with RAdamGC.

Ordovician Cephalopod Biofacies of South China and Its Provincialization

The research on biofacies and its provincialization is of important significance not only for the increasing of precision of stratigraphic subdivision and correlation in South China, the reconstruction of ancient environment and paleogeography and even the guiding of oil and gas exploration, but also for the study of paleobiogeogrphy and sea level changes of southern China in Ordovician. On the basis of the studies of the ecological characteristics of Ordovician cephalopods from South China, eighteen cephalopod biofacies are recognized and described ： （1） Open platform Proterocameroceras biofacies ; （2） Restricted platform Pseudoectenolites-Xiadongoceras biofacies; （ 3 ） Open platform Retroclitendoceras- Pararetroclitendoceras biofacies; （4） Open platform Pronajaceras-Mamagouceras biofacies ; （5） Shelf slope-basin Cyclostomiceras biofacies; （6） Open platform Cameroceras-Cyrtovaginoceras biofacies; （7） Open platform Coreanoceras-Manchuroceras biofacies; （8） Shelf slope-basin Kaipingoceras- Kyminoceras biofacies; （9） Inner shelf Bathmoceras-Protocycloceras biofacies; （10） Middle shelf Dideroceras-Ancistroceras biofacies; （11） Deep-water shelf Lituites-Cyclolituites biofacies ; （12） Stag- nant basin Lituites-Trilacinoceras biofacies; （13） Deep-water basin Paraendoceras-Sactorthoceras biofacies; （14） Deep-water shelf Sinoceras-Michelinoceras-Disoceras biofacies; （15） Deep-water shelf Beloitoceros-Jiangshanoceras biofacies; （16） Deep-water shelf-basin Eurasiaticoceras biofacies; （ 17 ） Shelf-slope Jiangxiceras-Yushanoceras biofacies; （18） Deep-water basin Michelinoceras biofacies. The cephalopods of these biofacies, their ecological characteristics, and living conditions are elucidated in this article. The association law of cephalopod biofacies in time and space shows that there were three cephalopod biofacies provinces in South China during the Ordovician, i.e. , Yangtze biofacies province, East Guizhou （贵州）-West Hunan （湖南） biofacies province （mixed-type biofacies province）, and Central Hunan-West Zhejiang （浙江） biofacies province. It is suggested that differentiation of cephalopod biofacies was mainly controlled by sea level changes and tectonic evolution. The differentiation is obvious during lower sea level and not developed during high sea level.

舟山渔场及邻近海域头足类(Cephalopod)种类组成和数量分布

根据2006年8月、2007年1月、5月和11月4个季节在舟山渔场及邻近海域(29°30′N—32°00′N,127°00′E以西)开展海洋生态系统综合调查所获得的头足类资料,用渔获率作为头足类分布的数量指标,分析了该海域的头足类种类组成、数量分布以及季节变化趋势。结果表明,该海域共鉴定头足类25种,隶属于3目8科9属。以浅海种类为主,渔获量以长蛸、短蛸较高,分别占头足类总渔获量的34.93%、30.06%,另外,神户枪乌贼、双喙耳乌贼等也占有一定比例。渔获量高峰期主要出现在夏季,以长江口渔场和舟山渔场为较高,春季以长江口渔场和江外渔场相对较高,秋季头足类在舟山渔场的出现率高于长江口渔场,但是平均渔获率以长江口渔场为最高。冬季调查海域的头足类数量不多,分布较分散,仅在长江口渔场的个别站位有出现。与以往的调查结果比较,该海域头足类群落结构发生了很大的变化,以往的优势种类——日本无针乌贼已严重衰退,从优势种类更替为浅海小型种类。

Phylogeny of the cuttlefishes (Mollusca: Cephalopoda) based on mitochondrial COI and 16S rRNA gene sequence data

To clarify cuttlefish phylogeny, mitochondrial cytochrome c oxidase subunit I (COI) gene and partial 16S rRNA geneare sequenced for 13 cephalopod species. Phylogenetic trees are constructed, with the neighbor-joining method.Coleoids are divided into two main lineages, Decabrachia and Octobrachia. The monophyly of the order Sepioidea,which includes the families Sepiidae, Sepiolidae and Idiosepiidae , is not supported. From the two families ofSepioidea examined, the Sepiolidae are polyphyletic and are excluded from the order. On the basis of 16S rRNA andamino acid of COI gene sequences data, the two genera (Sepiella and Sepia) from the Sepiidae can be distinguished, butdo not have a visible boundary using COI gene sequences. The reason is explained. This suggests that the 16S rDNAof cephalopods is a precious tool to analyze taxonomic relationships at the genus level, and COI gene is fitter at ahigher taxonomic level (i.e., family).

Replacements of Major Cephalopod Faunas in Late Cambrian and Ordovician in South China

1 Introduction As one of the major groups in the Great Ordovician Biodiversification Event(GOBE),cephalopods may have played a critical role in the marine ecosystem in late Cambrian and Ordovician.Among the few predators in the Ordovician,cephalopods are typified by their big sizes and the development of swimming ability.

Morphologies of Eumelanins from the Ink of Six Cephalopods Species Measured by Atomic Force Microscopy

The morphologies of eumelanin, isolated from the six cephalopods species Sepia esculenta, Sepia lycidas, Sepia pharaonis, Sepiella japonica, Euprymna berryi, and Uroteuthis(Photololigo) edulis, were investigated using atomic force microscopy(AFM). The results showed that the hierarchical aggregate structures of irregular spherical particles with different diameters are the common characteristics of these eumelanins. Furthermore, the diameters of these spherical particles present an uneven distribution in a wide range and mainly concentrate in the range of about 20-150 nm. In addition, the eumelanin from different cephalopods species show obvious differences in the morphologies, which is illustrated by different assembly forms of diverse aggregate units and the quantitative features of eumelanin particles derived from the images.

Comparative Taxonomical Studies on the Egyptian Red Sea Cephalopods (Cephalopoda: Mollusca)

Cephalopods are known to be commercially important around the world. Worth mentioning it constitutes a major part of the Egyptian fishing industry. Samples of cephalopods were collected from fishing boats in the Suez Gulf and Egyptian Red Sea. Cuttlefishes, squids, and octopuses had their club of the tentacle, arm IV hectocotylus, sucker of the club of the tentacle, sucker ring of the club of the tentacle, arm sucker, arm sucker ring, radula, gill, and shell. Various organs were photographed using a Canon G7X digital Camera. Eleven Egyptian Red Sea cephalopod species were encountered;three of them are cuttlefish species namely: Sepia dollfusi, Sepia pharaonis, and Sepia elongata. Three squid species namely: Loligo forbesii, Uroteuthis Photololigo duvaucelii, and Sepioteuthis lessoniana were also encountered. Five octopus species were also recorded namely: Octopus vulgaris, Callistoctopus macropus, Macrotritopus defilippi, Amphyoctopus aegina, and Amphyoctopus membranaceus. Aims of the current work are to differentiate between some Cephalopod species living in the Red Sea of Egypt and evaluate the status to achieve a reliable differentiation between these species.

阿根廷滑柔鱼能量积累的食物组成及其生态角色的研究进展

阿根廷滑柔鱼(Illex argentinus)是生长速度快、终生一次繁殖产卵、生命周期短的大洋浅海性头足类,也是世界上重要的经济物种。在西南大西洋生态系统中,阿根廷滑柔鱼发挥着重要的“生物泵”作用。在短暂的生命周期里,阿根廷滑柔鱼具有索饵–生殖洄游的生活史特征,并采取收入–资本混合型的生殖投入策略,即以现场摄食饵料吸收转化的能量投入为主、肌肉存储能量投入为辅。在不同的栖息海域与生长发育阶段,阿根廷滑柔鱼具有不同的食物组成。本文扼要概述阿根廷滑柔鱼的组织能量积累特点、能量积累过程的食物组成变化以及在西南大西洋生态系统中作为能量传输者的生态角色。同时,探讨了阿根廷滑柔鱼能量积累需求与洄游、摄食策略的关系,并对阿根廷滑柔鱼作为海洋食物网能量传输者的生态角色在气候变化、渔业活动背景下的变化做了展望分析,可为持续开发该种类资源提供资料参考。

气候变化事件对头足类繁殖、年龄生长与早期生活史影响的研究进展

头足类是重要的渔业资源之一,其渔业生物学特性极易受到海洋环境变化的影响。气候系统中的能量主要储存载体是海洋。近年来频发的气候变化事件引发海洋环境因子变动,直接或间接地改变了头足类的渔业生物学特性,对头足类的渔业生产造成影响。为此,本文归纳和总结了气候变化对头足类繁殖、年龄生长与早期生活史等3个方面的影响,并提出了展望。结果表明,气候变化事件的发生极易影响头足类动物的渔业生物学特性,海洋环境因子中的温度和初级生产力变动为主要影响因素。目前,相关研究对象多为柔鱼科和枪乌贼科等经济种类,选用的海洋环境因子也多为海洋环境温度,今后应结合其他海洋环境数据研究气候变化事件对其他种类的影响。本文旨为研究气候变化事件对头足类渔业生物学特性的影响提供理论依据,为近年来气候变化事件频发下头足类渔业的可持续发展提供科学指导。

基于增强回归树的西非北部沿海底拖网主要商业头足类CPUE与主要环境因子的关系

【目的】研究西非北部沿海不同环境因子对章鱼、墨鱼和鱿鱼等主要商业头足类单位捕捞努力量(CPUE)影响的规律,为合理规划商业性捕捞生产和科学渔业管理等提供参考。【方法】基于2019-2021年西非北部沿海底拖网渔业数据,使用增强回归树模型(BRT)分析主要商业头足类对于海表面温度(SST)、叶绿素质量浓度、海表面盐度、海表面高度异常,溶解氧浓度、降水量、经度、纬度、海底深度、离岸距离和时间等环境因子的响应规律。【结果与结论】BRT模型在渔业研究中尤其在数据处理方面较传统模型优势明显。本研究以相对重要性值划分11个环境因子对于商业头足类(章鱼、墨鱼和鱿鱼)CPUE影响的强弱:强重要性(10%以上)、一般重要性(5%~10%)和弱重要性(5%以下)。BRT拟合结果表明,SST、纬度、降水量和离岸距离对章鱼CPUE影响有强重要性,纬度、SST、叶绿素质量浓度对墨鱼CPUE影响有强重要性,而降水量、溶解氧浓度、SST对于鱿鱼CPUE影响有强重要性。纬度对章鱼和墨鱼的CPUE影响有强重要性,较高的CPUE分别出现在24°N以南(章鱼)和23°N―27°N之间(墨鱼);离岸距离对章鱼和鱿鱼CPUE影响均在一般重要性以上,离岸30~70 km范围内CPUE较高;3种头足类中,鱿鱼CPUE受时间影响最大,较高CPUE出现在1月和7月。环境因子中,SST对3种头足类影响均有强重要性,相对重要性均在20%以上,其中对于章鱼和墨鱼影响效应相反,章鱼趋暖而墨鱼趋寒;溶解氧浓度与鱿鱼CPUE呈正相关;叶绿素质量浓度对墨鱼CPUE影响有强重要性,叶绿素质量浓度较低时CPUE较平稳,但当质量浓度超过4 mg·m^(-3)时CPUE却逐渐下降。降水量对于3种头足类CPUE影响均在一般重要性以上,随降水量增加,鱿鱼CPUE有所上升,而章鱼和墨鱼CPUE先升高后降低。

Hearing characteristics of cephalopods: Modeling and environmental impact study

Cephalopods(octopus,squid and cuttlefish)are some of the most intriguing molluscs,and they represent economically important commercial marine species for fisheries.Previous studies have shown that cephalopods are sensitive to underwater particle motion,especially at low frequencies in the order of 10 Hz.The present paper deals with quantitative modeling of the statocyst system in three cephalopod species:Octopus vulgaris,Sepia officinalis and Loligo vulgaris.The octopus’s macula/statolith organ was modeled as a 2nd-order dynamic oscillator using parameter values estimated from scanning electron micrograph images.The modeling results agree reasonably well with experimental data(acceleration threshold)in the three cephalopod species.Insights made from quantitative modeling and simulating the particle motion sensing mechanism of cephalopods elucidated their underwater particle motion detection capabilities.Sensitivity to emerging environmental issues,such as low frequency noise caused by near-shore wind farms and increasing levels of carbon dioxide in the ocean,and sensitivity to sounds produced by impending landslides were investigated in octopus using the model.

中国海域头足类物种多样性

本文回顾了中国头足类物种多样性研究历史,分析了头足类的种类组成、分布特点,结果显示中国海域头足类记录的有效现存种达154种,隶属于34科79属:鹦鹉螺目1科1属1种,乌贼目3科12属37种,闭眼鱿目1科4属13种,开眼鱿目17科38属47种,八腕目8科20属51种,幽灵蛸目1科1属1种,未定目3科3属4种。渤海、黄海、东海和南海的头足类种类组成存在显著差异性,呈自北(渤海)向南(南海)逐渐增多的趋势:渤海9种,黄海15种,东海91种,南海140种。结合上述研究结果和国内外研究现状、发展趋势,对深入开展头足类多样性研究提出了建议。

阿根廷滑柔鱼(Illex argentinus)雌性成熟个体的有效繁殖力及有效生殖投入

为掌握阿根廷滑柔鱼繁殖特性,根据2021年在西南大西洋公海采集到的阿根廷滑柔鱼样本进行计数和分析雌性成熟个体有效繁殖力,并利用能量密度测定技术测定分析其有效生殖投入。结果显示,阿根廷滑柔鱼雌性成熟个体的平均胴长为(244.90±16.36)mm,平均体质量为(295.16±64.85)g。雌性成熟个体的有效繁殖力为24363~102633粒卵母细胞,平均有效繁殖力为(63158.49±16782.00)粒卵母细胞;卵子能量密度值为25.01~26.09kJ/g,平均值为(25.71±0.25)k J/g;有效生殖投入为219.80~817.06 kJ,平均有效生殖投入为(465.02±158.71)kJ。在功能性成熟期,雌性个体的有效繁殖力和有效生殖投入均达到最大值。然而,自成熟度Ⅳ期至Ⅵ期,卵子能量密度值、体质量相对有效繁殖力、体质量相对有效生殖投入均没有显著差异。同时,混合模型结果显示,雌性成熟个体的有效繁殖力和有效生殖投入均随着体质量增加显著增大,但与个体体征没有显著相关性。结果表明,阿根廷滑柔鱼雌性成熟个体的有效繁殖力和有效生殖投入均与成熟体型大小密切相关,然而不同发育时期的个体具有稳定的单位质量有效繁殖力和单位质量有效生殖投入。

黔北上奥陶统宝塔组头足类的聚爆深度分析及其地质学意义

上奥陶统宝塔组是扬子板块分布广泛的标志性地层单元,因富含类型多样的头足类化石及发育特殊的网纹状构造而闻名。目前,有关宝塔组沉积时期水体深度的分析都是基于沉积学和古生物学特征的定性推测,而且争议较大。笔者等在黔北尧龙山地区宝塔组采集到大量原域埋藏的头足类化石,根据它们的隔壁强度系数(Septal Strength Index,SSI)与聚爆深度的耦合关系,首次对这些头足类生活时的古海水深度进行定量化分析。通过选取符合SSI分析条件的16块Sinoceras和12块Michelinoceras标本,系统分析了SSI分别与外部特征和内部构造的相关性。结果显示,SSI随壳体长度及隔壁间距的增大而增加,随顶角角度的增加而减小,但与内部构造单一参数的相关性不大,可能受到多个内部构造参数的共同制约。定量化分析结果显示,尧龙山地区宝塔组中共埋出现的Sinoceras和Michelinoceras的SSI分别为5.564~10.829和11.432~19.532,对应的生态深度大约分别为128~169 m和228~280 m,表明两属头足动物生活时可能已经出现明显的生态分层现象,古生物地理区系也出现一定的差异。不过,两个属内部不同种的生态深度没有明显差别。头足类的生态深度分析结果表明,研究区宝塔组沉积时期的水体深度可能大于280 m,远比前人分析的结果深得多。

头足类角质颚研究进展Ⅰ——形态、结构与生长

头足类通常为一年生种类,是典型的短周期生命物种。鉴于其特殊的生活史特点,及其在海洋生态系统中占据的重要地位,各国学者越来越关注头足类的基础生物学。角质颚作为重要的硬组织之一,具有形态相对稳定且不易腐蚀等特点,近些年来对其内部结构组成和微结构的研究越来越多,其几丁质结构和黑色素沉着的变化也得到很大的关注。本文基于前人对角质颚在形态、生化结构和年龄生长方面的研究进行回顾,并对近几十年来的研究方向展开分析。结果认为,角质颚的研究方向应该从定性到定量分析开始转变,并且要更加关注角质颚形状变化与其生化结构和生长等规律性变化之间的关系。

利用耳石鉴定头足类年龄与生长研究进展

年龄和生长是头足类生物学研究的重点内容,利用耳石轮纹鉴定其年龄、分析其生长特性是一种可靠而有效的方法。耳石经提取、研磨、抛光后制备成切片,对切片观察面轮纹进行计数可得到日龄。研磨平面的选择是头足类耳石制片的最关键步骤,通常选择纵截面研磨。轮纹计数时,一般选择轮纹相对比较清晰的背区计数。适合头足类的生长模型有线性、指数、幂函数、逻辑斯谛、Gompertz和Von Bertalanffy等多种。分析认为,同一种头足类在不同生长阶段以及不同种群间,其年龄组成、生长率以及适合的生长模型往往不同,因此,建议应先对研究对象进行不同产卵季节或地理种群的划分,然后根据不同种群分别研究其生长并建立生长模型。

东海区头足类群聚空间分布特征的初步研究

根据2000年东海区（27°00’～34°00’N、127°00’E以西海域）150m等深线以浅4个季节的底拖网监测调查资料，运用聚类分析和非度量多维标度（NMDS）的方法分析东海区头足类群聚的空间分布特征，并且探讨各个群聚类型的指示种类以及头足类群聚分布与环境的关系。头足类主要种类为剑尖枪乌贼（Loligo edulis）、太平洋褶柔鱼（Todarodes pacificus）、金乌贼（Sepia esculenta）等。多元分析结果显示，各季节头足类群聚类型不同。根据各群聚类型分布的海域大致可以将其划分为黄海南部-东海外海-东海中南部群聚、长江口外海域群聚和东海北部海域群聚3种群聚类型。它们的空间分布区域随着季节的不同而发生变化，群聚类型的分布区域也会相互交错。各季节不同群聚类型的种类组成不同，多数种类一般同时出现于不同的类群中，有的种类在所有群聚类型中都有分布。它们的空间分布也是交错的，只是相对集中的区域有所不同，在不同群聚类型中的渔获率和出现频率不同。头足类各群聚类型种类组成的季节差异较明显，各群聚类型中相对稳定的主要特征种类较少。调查海域中影响头足类种类空间分布特征的主要环境因子为水温，而水深等环境因素的影响并不明显。

东海南部海域头足类群落结构特征及其与环境关系

根据2008年春(5月)、夏(8月)、秋(11月)、冬(2009年2月)四季东海区桁杆拖虾网调查期间所采集的头足类资料,分析了东海南部海域头足类种类组成及优势种,采用生态多样性指数分析了群落物种多样性,并运用典范对应分析法研究了头足类群落变化与主要环境因子的关系。结果表明:东海南部海域共捕获头足类22种,隶属于3目6科8属,优势种主要有神户乌贼(Sepia kobiensis)、双喙耳乌贼(Sepiola birostrata)、短蛸(Octopus ocellutus)和杜氏枪乌贼(Loligo duvaucelii)等;种类丰富度指数D变化范围为0—1.30,多样性指数H′变化范围为0—1.69,均匀度指数J变化范围为0.02—1.00,t检验表明,各群落多样性指数四季之间的差异均不显著(P>0.05);根据典范对应分析认为,底层水温为影响调查海域头足类种类组成的主要环境因子。

东海区头足类资源现状与合理利用的探讨

根据有关调查、生产和文献资料，较系统地阐明：东海区头足类的种类组成共有７８种，隶属４目，２０科，３８属；产量变动呈上升趋势；其中剑尖枪乌贼的主要渔场为东海南部、中部外海和五岛对马海区渔场，渔期为５～１０月；该种的生物学特征及其与环境的关系等。文中还分析了头足类资源前景，提出了合理利用意见。