两个新的桃花水母形态度量学参数的建立及其在种类区分上的应用

桃花水母属一些种类命名的有效性仍存在争议,本文建立了两个新的形态度量学参数,即触手密集度和平衡囊密集度,采用形态度量学方法对在我国采集到的索氏桃花水母、嘉定桃花水母、中华桃花水母和短手桃花水母进行了比较研究,并讨论这两个参数在种类区分上的应用。此外,利用Spearman秩相关系数检验桃花水母各形态学参数之间的相关性。结果表明,短手桃花水母和中华桃花水母在形态上没有明显的差异,可能与中华桃花水母为同一物种。嘉定桃花水母与中华桃花水母和索氏桃花水母在形态上均存在显著的差异,应该是一个有效种。桃花水母的触手数和平衡囊数均与伞径显著正相关,除嘉定桃花水母外,其他三种桃花水母的平衡囊密集度都与触手密集度显著正相关。     

贵州福泉的索氏桃花水母生长及 精巢发育初步研究

2017年10月中旬,在贵州省福泉县一个池塘中发现了桃花水母,经分子鉴定确认为索氏桃花水母（Craspedacusta sowerbyi）。研究了其生长发育的情况,建立了拟合优度线性相关函数,并观察了雄性索氏桃花水母精巢外形发育过程。结果表明,福泉的索氏桃花水母雌雄异体,雌性触手细长,伸向上方;雄性触手短粗,垂向下方。缘膜宽度、口径宽度、触手数量与伞径相关函数的相关系数r均大于0.75,说明3个指标与伞径之间均存在极强正相关关系。福泉的索氏桃花水母雄性个体性腺4个,淡绿色,成熟雄性个体精巢呈囊状、三角囊状、长三角囊状,4个精巢的发育不同步。研究表明,当伞径小于12 mm时,福泉的索氏桃花水母处于生长发育期,缘膜、口径宽度、触手数量、雄性精巢4个性状随之增长而变化,当伞径大于等于12 mm时,个体处于成熟期,上述4个性状相对稳定,变化不大。本文对于性腺作为桃花水母分类指标的有效性做了探讨。     

厦门和平水母属一新种(刺胞水母门,软水母亚纲,和平水母科)

记述了采自厦门海域和平水母属Eirene Eschscholtz,1829 1新种,厦门和平水母,新种Eirene xiamenensis sp.nov.,其鉴别特征如下:伞半球形,胶质厚;胃柄基部宽,胃柄长为伞径1/4;垂管短,口有4个长于垂管的皱褶口唇;生殖腺长椭圆形,位于辐管中部和胃柄基部之间;缘触手24～41条,触手基部具有排泄乳突;每2条触手间有1～3个平衡囊,多数为2个.     

安徽省桃花水母的初步研究

桃花水母属Craspedacusta隶属于刺胞动物门Cnidaria水螅纲Hydrozoa淡水水母目Limnomedusae笠水母科Olindiidae。我国的桃花水母种类丰富,分布广泛,近年来多地有新种和分布新纪录的报道。安徽曾发现桃花水母,但均未进行详细描述和研究。本文对采自安徽省金寨县梅河河谷水潭内的桃花水母进行了初步研究,依据其伞形、缘膜宽度、触手及平衡囊数目、刺丝囊疣形状和排列方式、生殖腺形状和颜色等形态特征对其进行初步的分类鉴定。结果表明,此次在金寨县发现的桃花水母更接近于宜昌桃花水母Craspedacusta kawaii Oka,1907。这是对安徽省发现的桃花水母首次进行较为明确的分类鉴定和初步的形态学研究。     

中国南海北部北部湾水母类调查及三新种记述(刺胞动物门)(英文)

材料系于2007年(1,4,7,10月)、2008年(1,7月)和2009年(1月)在北部湾水域采集的,调查海区共设52站,共采集364份样品。经分析鉴定出67种水母,其中有3新种和中国2新纪录,主辐特古水母Tregouboiva perradialis Xu,Huang et Du,sp. nov.,泡真囊水母Euphysora vacuola Xu,Huang et Guo,sp. nov.,波腺侧丝水母Helgicirrha sinuatus Xu,Huang et Du,sp. nov.,艾格帝纹水母Timoides agassizi Bigelow,1904和大腺美螅水母Clytia macrogonia Bouillon,1984。此外,还报道了20种水母为北部湾新纪录。模式标本保存在中国水产科学研究院南海水产研究所。主辐特古水母,新种Tregoubovia perradialis Xu,Huang et Du,sp. nov.鉴别特征伞近钟形,外伞有16条双层向心肋; 垂管很大,近方形,约为内伞腔深度4/5;口有4个延长成触手状的口唇,具环状刺胞,无末端刺胞球;隔膜短;4个大的椭圆形生殖腺,几乎覆盖整个垂管主辐位;伞缘无缘触手或缘基球;无眼点。正模(BG 001),北部湾S30站(17°30’N,107°30’E;水深70m),2008-07-06,梁新采(南海水产研究所)。词源:新种种名源自拉丁词perradialis,意为生殖腺位于垂管主辐位。泡真囊水母,新种Euphysora vacuola Xu,Huang et Guo,sp. nov.鉴别特征伞有钝圆形顶突;垂管长椭圆形,约有1/2长度超出缘膜口外,垂管基部很宽,覆盖着浓密泡状细胞组织;4条辐管上部与扩大的垂管基部连接;生殖腺围绕着垂管壁;主触手很长,触手基球很大,呈卵圆形至球形,触手上具30～40个成排的背轴刺胞球,无末端膨大刺胞球,另3个触手基球退化,很小,同样大小,无丝状触手,每个基球具外胚层背距。正模(BG 006),北部湾C15站(20°N,109°E;水深44m),2007-07-25,梁新采(南海水产研究所)。副模(TB001),台湾海峡102站(23°40’N,118°44’E;水深54m),1988-06-29,黄加祺采(厦门大学海洋学系)。词源:新种种名源自拉丁词vacuola,意为该种在垂管基部覆盖浓密泡状细胞组织。波腺侧丝水母,新种 Helgicirrha sinuatus Xu,Huang et Du,sp.nov.鉴别特征伞略扁于半球形;胃柄长,约有1/2超出缘膜口外,垂管短小,口有4个短的略为向上弯曲折叠的口唇;生殖腺深波形,位于辐管远端1/3处; 16 ～ 24 条缘触手,每条触手具2对侧丝,每2条触手间有3～5个缘疣,具1对侧丝和3～4个平衡囊,每个平衡囊有2～4个平衡石;所有触手和缘疣基部均有向轴排泄乳突。正模(BG 007),副模(BG 008-009),北部湾S18站( 18°45’N,106°45’E;水深53m),2007-04-15,梁新采(南海水产研究所)。词源:新种种名源自拉丁词sinuatus,意为该种生殖腺深波状。     

闽南-粤东近海上升流区花水母亚纲一新属二新种记述(丝螅水母目,原帽水母科;头螅水母目,棒状水母科)

记述了闽南-粤东近海上升流区花水母亚纲原帽水母科Protiaridae Haeckel,1879裸球拟海帽水母1新种Halitiarella nudibulbus Xu,Huang et Guo,sp.nov.与棒状水母科Corymorphidae Allman,1872张氏八辐端粗水母1新属1新种Octovannuccia zhangjinbiaoi Xu,Huang et Lin,gen.nov.,sp.nov.。模式标本保存在国家海洋局第三海洋研究所。裸球拟海帽水母,新种Halitiarella nudibulbus Xu,Huang et Guo,sp.nov.(图1～2)鉴别特征水母伞无顶突,外伞有分散刺胞;伞缘有4条主辐位触手和4个间辐位缘基球,所有触手和缘基球有背轴眼点;主辐位触手与间辐位缘基球间具2～3条短的实心缘丝。正模(TS045)和副模(TS046-049),闽南-粤东上升流区A25站(22.8°N,118.1°E),水深32m,2009-06-11,项鹏采(第三海洋研究所)。词源:新种以拉丁词nudibulbus为种名,意为裸球,指该种间辐位缘基球无触手。八辐端粗水母,新属Octova...     

白色霞水母生活史的实验室观察

本文首次描述了白色霞水母从受精卵至碟状体的生活史。(1)包括受精卵、卵裂、囊胚以及浮浪幼虫等在内的胚胎发育各期均在开放的水体中,在20·8 -21·4℃浮浪幼虫于受精后14 h出现; (2)浮浪幼虫在定置前形成一种凸面的圆形浮浪幼体囊,除了浮浪体囊外,螅状体还可产生足囊和通过产生匍匐茎形成囊胞进而发育成新的螅状体; (3)尽管偶而产生2个碟状体但仍为典型的单碟型横裂; (4)新释放的碟状幼体绝大多数为8个缘叶, 8个感觉棍和8对钝圆的缘瓣,但畸形个体最多12个,最少6个缘叶; (5)雌雄个体间的交互作用对产卵和受精是非常重要的因子[动物学报52 (2) : 389 -395 , 2006]。     

温度、投饵频次对白色霞水母无性繁殖与螅状体生长的影响

白色霞水母是我国近海主要大型灾害水母种类之一,其暴发性增殖严重破坏了海洋生态系统平衡.在室内控制条件下,研究了温度(7.5、11、14.5、18、21.5和25℃)和投饵频次(1次/2d、1次/8d和1次/16d)对白色霞水母无性繁殖与螅状体生长的影响.结果显示,白色霞水母足囊繁殖的适宜温度为18-25℃,足囊繁殖随温度和投饵频次的增加而增加.温度对白色霞水母横裂率和横裂次数的影响显著,温度越高,白色霞水母发生横裂生殖的时间越早,横裂生殖速度越快,重复横裂次数越多,释放的碟状体数量也越多.横裂率和横裂次数随投饵频次的增加而递增.白色霞水母螅状体在7.5-25℃范围的成活率均为100％,其生长速度随温度和投饵频次的增加而增加.温度和投饵频次对白色霞水母螅状体足囊繁殖、横裂率和螅状体生长具有明显的交互效应.螅状体的横裂次数和初生碟状幼体伞径随螅状体柄径增大而递增,呈线性相关.研究表明,温度、投饵频次即营养条件显著影响着白色霞水母的种群数量,说明海水水温上升、富营养化或渔业资源锐减导致的浮游动物量增加均可能诱发白色霞水母暴发性增殖.结论为进一步探索大型水母暴发的生态环境机理提供重要科学依据.     

莱州湾水母种类多样性及群集结构的季节变化

基于2011年5月至2012年4月(除冰期12月和翌年1—2月外)在渤海莱州湾逐月采集的数据资料,系统地开展水母种类组成、数量分布的周年季节变动,弥补自20世纪90年代以来该区域相关资料的不足,有利于掌握该水域水母(主要是小型水母)主要种类数量时空分布特点,促进莱州湾生物类群对生境改变响应的相关研究。结果显示:所有调查中,共出现水母30种,无全年出现的种类。各月中,莱州湾水母以8月种数最多,5月数量居多。各月水母总数量的80%多由1—2种优势种贡献所致;水母优势种类组成季节更替明显。3—5月优势种为八斑唇腕水母;6月为嵊山秀氏水母和贝氏真囊水母;7月为贝氏真囊水母、9月有细颈和平水母;10月为细颈和平水母和大西洋五角水母,8月和11月无明显的优势种,但8月细颈和平水母和曲膝薮枝螅水母数量较多。莱州湾小型水母聚集结构主要呈现季节性时间格局上的变动。春季有八斑唇腕水母为代表、在湾内分布的聚集组;夏季有以嵊山秀氏水母和贝氏真囊水母为代表、在湾口西侧和湾中部分布的聚集组,以及细颈和平水母为代表、在湾中底部分布的聚集组;秋季有四枝管水母和大西洋五角水母为代表、在湾口和中部分布的聚集组。水温对小型水母聚集结构分布具有较为重要的影响作用。大型水母在本调查出现较少。海蜇和沙海蜇出现于6—8月个别站位;海月水母7—10月均有出现,但高密集区出现在10月紧邻莱州湾的湾底水域。     

长江口及临近海域夏季水母类分布特征

采用1998年8月,1999年8月长江口及其临近海域（121°15′E-122°41′E,30°00′N-31°30′N）的调查资料,对采集到的水母样品进行分析,探讨水母的分布特征以及影响因素。结果表明：调查海域共出现水母21种,其中水螅水母15种,管水母4种,栉水母2种;可分为近岸低盐性、低盐河口性和大洋暖水性3个生态类群,其中近岸低盐物种达60％以上,分布范围广,低盐河口类群仅出现于受长江冲淡水影响明显的低盐水域,而大洋暖水类群分布于受外海水影响较大、盐度较高、离岸较远的区域;优势种为贝氏拟线水母、球型侧腕水母、单囊美螅水母、五角水母、拟细浅室水母和双生水母。总体分布特征为：从长江口向外伴随着盐度的逐渐增大．丰度逐渐升高,在长江）中淡水与外海水交汇的舟山渔场西部水域,丰度最大;水母的出现种类、丰度均与东海外海水、长江冲淡水2大水系的配置有关：外海水越强,整个区域平均盐度较高,出现的水母种类、丰度均高;反之,长江冲淡水势力控制范围大,平均盐度明显降低,物种少且丰度低。     

Statocysts of hydromedusae

The statocysts of Leptomedusae are formed as a depression in the velum. They are lined on the inside towards the distal part of the velum by thin epithelium and towards the proximal part by ciliated sensory cells. Lithocytes are present in the centre. The concretion contains calcium sulphate and in some cases, calcium phosphate is also present in addition to some membranous material. The statocysts of Narcomedusae arise from the exumbrellar nerve ring as free sensory clubs. They have a proximal basal cushion of sensory cells from the centre of which arises a sensory club (Aegina) or a sensory papilla carrying a sensory club (Solmissus). The sensory club has an axial strand of endodermal cells covered by ciliated sensory cells. Some of the endodermal cells have a concretion. While the statocysts of Leptomedusae are totally ectodermal, those of Narcomedusae are ecto-endodermal in origin. The sensory cilia of Leptomedusae, especially those present on the sensory cells adjacent to the lithocyte, run close and parallel to the lithocyte membrane. In Narcomedusae the sensory cilia of the basal cusion and sensory papilla are tall and strong. Ciliary rootlets are missing in the sensory cilia of Leptomedusae and in the sensory club of Narcomedusae but they are strongly developed in the cilia of basal cusion and sensory papilla. The cilia have 9+2 filament content. A ring of stereocilia surrounds the kinocilium of the sensory club cells. Mechanism of statocyst function is discussed.     

Locomotion and neuromuscular system of Aglantha digitale

Aglantha digitale swims in two ways: a slow rhythmical swim typical of hydromedusae in general and a sudden rapid movement that appears to be an escape response. The swimming musculature is an extremely well developed striated circular muscle layer that possesses a sarcoplasmic reticulum. The nervous system of this species can be divided into three units: an inner nerve ring and an outer nerve ring, which are joined by unusually large transmesogleal pathways, a group of giant axons that extends over the surface of the swimming muscle, and the radial canal. Well developed ciliated sensory cells are located on the exumbrellar surface of the margin. Consideration of these properties of the organisation of this species suggests that normal slow swimming is controlled by a mechanism similar to that found in other medusae, while the escape response is the result of the action of the giant axons.     

Ultrastructure of the Statocysts in the Apodous Sea Cucumber Leptosynapta inhaerens (Holothuroidea, Echinodermata)

The burrowing sea cucumber Leptosynapta inhaerens possesses five pairs of statocysts, one pair on either side of each radial nerve cord where it arises from the circumoral nerve ring. The nerve cords exhibit only ectoneural components at the level of the statocysts. A sinus-like epineural canal lies superjacent to each cord. This canal is lined by a robust monociliated neuroepithelium which lacks any special support cells. Beneath the neuroepithelium, the somata of the ectoneural neurons form a perikaryal layer whereas the axons are located within the proximal parts of the cords. Glial cells have not been found. Each statocyst is a hollow sense organ. Its central cavity is lined by a monolayer of monociliated parietal cells. Axons of these parietal cells extend towards the statocyst nerve which connects each statocyst with the ectoneural pathways of the cord. A single lithocyte floats within each central statocyst cavity. This unciliated cell contains a voluminous vacuole with the statolith and several smaller vacuoles. It is concluded that statocysts do not belong to the basic organization of the Holothuroidea but have been evolved within this group. The statement, that the statocysts of apodous sea cucumbers and that of the enigmatic Xenoturbella bocki are homologous organs, is rejected.     

Ultrastructure of Nuchal Organs in Polychaetes (Annelida) — New Results and Review

Nuchal organs are epidermal sensory structures present in most polychaetes. They are situated at the posterior edge of the prostomium and may extend posteriorly onto the peristomium. Although there is considerable external variation, they all consist of ciliated supporting cells, bipolar primary sensory cells and retractor muscles. They are innervated directly from the brain by paired nerves. The sensory cells are usually monociliated; their sensory processes lie in subcuticular spaces, the olfactory chambers. Structural variability is to be observed in the location of the sensory cells, the course of the nuchal nerve, position of nuchal ganglia as well as in cytological features of sensory and supporting cells. These differences provide useful characters for phylogenetic considerations to establish supraspecific taxa within the phylogenetic system of the Annelida. Special emphasis is laid on the problem of whether the nuchal organs represent an autapomorphy of the Polychaeta or the Annelida and thus whether the lack of nuchal organs in Clitellata is primary or secondary. As is discussed, the probability of a loss of the nuchal organs in Clitellata is higher, which favours the second hypothesis: that nuchal organs are part of the ground pattern of the Annelida and very likely are an autapomorphy of this group.     

Sense organs in polychaetes (Annelida)

Polychaetes possess a wide range of sensory structures. These form sense organs of several kinds, including the appendages of the head region (palps, antennae, tentacular cirri), the appendages of the trunk region and pygidium (parapodial and pygidial cirri), the nuchal organs, the dorsal organs, the lateral organs, the eyes, the photoreceptor-like sense organs, the statocysts, various kinds of pharyngeal papillae as well as structurally peculiar sensory organs of still unknown function and the apical organs of trochophore larvae. Moreover, isolated or clustered sensory cells not obviously associated with other cell types are distributed all over the body. Whereas nuchal organs are typical for polychaetes and are lacking only in a few species, all other kinds of sensory organs are restricted to certain groups of taxa or species. Some have only been described in single species till now. Sensory cells are generally bipolar sensory cells and their cell bodies are either located peripherally within the epidermis or within the central nervous system. These sensory cells are usually ciliated and different types can be disinguished. Structure, function and phylogenetic importance of the sensory structures observed in polychaetes so far are reviewed. For evaluation of the relationships of the higher taxa in Annelida palps, nuchal organs and pigmented ocelli appear to be of special importance.     

Ultrastructure of epidermal sensory receptors in Amphibolurus barbatus (Lacertilis: Agamidae)

Summary The histological and ultrastructural organisation of the epidermal sensory organs in Amphibolurus barbatus has been described with respect to their position and possible functions. The sensory organs, located at the scale's edge, are most numerous in scales of the dorsal surface of the head. Most other scales of the body surface have two receptors located laterally to the spine or keel of the scale. In the imbricate scales of the ventral body region, the receptors lie just beneath the reinforced scale lip. Scanning electron microscopy has revealed the surface of the organ to be a crater lacking any surface projections. These sensory organs have a dermal papilla consisting of a nerve plexus and loose connective tissue. The nerve fibres arising from the plexus, pass to the epidermal columnar cells, where some form nerve terminals at the base of the cells, while others pass between them to form nerve terminals embedded in a superficial layer of cuboidal cells. The superficial terminals are held against the overlying keratin by masses of tonofilaments. The keratin is thickened to form a collar around the periphery of the organ but is only about 0.5 m thick immediately above it. Mechanical deformation of the scale's spine or reinforced scale lip may initiate stimulation of the nerve terminals described.     

The sphaeridia of sea urchins: ultrastructure and supposed function (Echinodermata,Echinoida)

Summary Sphaeridia are minute skeletal appendages of the echinoid test which are considered to be sense organs, organs of equilibrium, according to their shape. The sphaeridium forms a functional unit with the tubercle to which it adheres. The tubercle is encircled by a basiepithelial nerve ring of the epidermis. A circle of regularly arranged myocytes stretches from the tubercle to the sphaeridium. The muscles are distant from each other. The myofibrillar processes enter the pore space of the sphaeridial skeleton to which they are anchored by tendons; tendons are absent in the tubercle region. The cell bodies of the myocytes lie opposite to the nerve ring outside the skeleton. In this region the muscle cells and the nerve ring are in contact with each other, their basal laminae fuse. Tensions of the various myocytes are dependent on the position of the top-heavy sphaeridium. The nerve ring contains neurones which are provided with a cilium which lies close to the contact region with the myocytes. This arrangement leads to the assumption that the nerve cells in question have a proprioceptor function. Unique filter cells are present in the pore spaces of the sphaeridium and the tubercle. They possibly detoxicate the extracellular fluid that surrounds the myocytes. Phagocytes loaded with spacious phagosomes are crowded in the adjacent pore spaces. They are possibly extruded via the epidermis. Filter cells and phagocytes have obviously to do with the metabolism within the sphaeridium-tubercle-system.     

Structure and function of the Nautilus statocyst.

The two equilibrium receptor organs (statocysts) of Nautilus are avoid sacks, half-filled with numerous small, free-moving statoconia and half with endolymph. The inner surface of each statocyst is lined with 130,000-150,000 primary sensory hair cells. The hair cells are of two morphological types. Type A hair cells carry 10-15 kinocilia arranged in a single ciliary row; they are present in the ventral half of the statocyst. Type B hair cells carry 8-10 irregularly arranged kinocilia; they are present in the dorsal half of the statocyst. Both type of hair cells are morphologically polarized. To test whether these features allow the Nautilus statocyst to sense angular accelerations, behavioural experiments were performed to measure statocyst-dependent funnel movements during sinusoidal oscillations of restrained Nautilus around a vertical body axis. Such dynamic rotatory stimulation caused horizontal phase-locked movements of the funnel. The funnel movements were either in the same direction (compensatory funnel response), or in the opposite direction (funnel follow response) to that of the applied rotation. Compensatory funnel movements were also seen during optokinetic stimulation (with a black and white stripe pattern) and during stimulations in which optokinetic and statocyst stimulations were combined. These morphological and behavioural findings show that the statocysts of Nautilus, in addition to their function as gravity receptor organs, are able to detect rotatory movements (angular accelerations) without the specialized receptor systems (crista/cupula systems) that are found in the statocysts of coleoid cephalopods. The findings further indicate that both statocyst and visual inputs control compensatory funnel movements.