湖南淡水水母一新记录——信阳桃花水母

在湖南临澧采得淡水水母标本，伞径５３～１２０ｍｍ，平均伞径８．８ｍｍ，触手２６８～５８６条，平均４４７条，主辐触手４条显著长于其他触手，刺丝囊疣圆锥形呈环状排列，生殖腺呈长三角扁囊状，淡绿色；平衡囊呈管状，数量在７２～１５４个，平均为１０８个；经鉴定为信阳桃花水母（Ｃｒａｓｐｅｄａｃｕｓｔａｘｉｎｙａｎｇｅｎｓｉｓ），系湖南省分布的新记录。     

白色霞水母各发育阶段的形态

对白色霞水母从受精卵到成体水母各发育期的形态进行了描述。受精卵发育成带纤毛的浮 浪幼虫，浮浪幼虫在定置前形成一种凸面的圆形浮浪幼体囊, 经脱囊狭窄柄部拉长进而变成一个细长颈瓶形状，萌发出4个触手成为早期螅状体；螅状体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；横裂为典型的单碟型横裂；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，同时对海蜇与白色霞水母的碟状幼体形态进行了比较。成体水母伞径200～300 mm，大型个体超过500 mm。外伞表面光滑,近中央的伞顶上有许多密集的刺胞丛隆起, 8个缘叶，8个感觉棍,口腕非常发达，口腕上有大量刺细胞团。可根据感觉胃囊和触手囊是否连接、缘瓣水管的排列类型、外伞顶中央是否有刺细胞丛以及个体伞径和颜色对白色霞水母、发形霞水母、棕色霞水母和紫色霞水母进行鉴别。     

中国介螅水母属二新种（丝螅水母目，介螅水母科）

记述了台湾海峡及其邻近海区介螅水母科Hydractiniidae L.Agassiz,1862介螅水母属Hydractinia van Beneden,1841二新种,即螺旋介螅水母,新种Hydractinia spiralis sp. nov.和反曲介螅水母,新种Hydractinia recurvatus sp.nov.,兹将二新种主要鉴别特征描述于下:螺旋介螅水母,新种:伞无顶突;垂管长圆柱形,约为内伞腔深度2/3;口腕简单,末端具成束刺胞;生殖腺很大,呈椭圆形,几乎覆盖整个垂管间辐位,无水母芽;缘触手6条,4条主辐位,另2条仅在相对间辐位,基球延长锥状,同样大小,无眼点,触手长,近端2/3粗壮,远端1/3变细,具螺旋状刺胞。反曲介螅水母,新种:伞无顶突;垂管短小,呈方形;胃柄显著,约为垂管长度1/2;口有4个主辐位口唇,延长成向上反曲的短口腕,末端具成丛刺胞;4个卵圆形生殖腺,附在二个反曲口腕之间的垂管间辐位,无水母芽;缘触手16条,触手基球膨大,呈锥状,同样大小,整条触手具环状刺胞,末端略膨大,呈椭圆形。     

莱州湾霞水母大规模爆发危害影响分析

霞水母是钵水母纲旗口水母目的一属，体呈扁平盘状，伞径14～20cm。内伞有8束纵辐位U字形排列的触手，并有环肌束。霞水母中胶层很薄，不宜食用，经济价值很低，不具有捕捞意义，但是对趋业的危害却十分严重。     

箱形水母

箱形水母是一种淡蓝色的透明水母，形状像个箱子，有4个明显的侧面，每个面都有20cm长。其重要特征是伞体呈立体箱形状以及有4条较粗壮的触手。它的触须可达3m长，每条触须上布满了储存毒液的刺细胞。     

南海介螅水母属二新种(刺胞动物门、花水母亚纲、介螅水母科)

在分析南海浮游生物样品时,发现了花水母亚纲(Anthomedusae Haeckel,1879)丝螅水母目(Filifera Kühn,1913)介螅水母科(Hydractiniidae L.Agassiz,1862)介螅水母属(Hydractinia van Beneden,1841)2新种:缢介螅水母(H.constrictura sp.nov.)和叶状介螅水母(H.phyllosoma sp.nov.)。缢介螅水母的主要鉴别特征为伞近球形,无顶突;垂管长,其中部有一圈凹缢,把垂管分为2个部分,上端为泡状组织,下端为胃部,上有水母芽,口有4个口腕,口腕末端为刺胞球;生殖腺位于垂管间辐位;4条短的缘触手,触手基球球状,无眼点,触手上具环状刺胞,末端具刺胞球。叶状介螅水母的主要鉴别特征为伞钟形,胶质薄,无顶突;垂管短,无胃柄,口方形,有4个叶片状口唇,口唇上长满刺细胞;生殖腺分布在垂管上,间辐位,无水母芽;4条单生触手。模式标本保存于国家海洋局第三海洋研究所。     

咖啡金黄水母全人工繁殖和选优试验

<正>咖啡金黄水母(Ghrysaora melanaste),别名咖啡海刺水母,隶属腔肠动物门、钵水母纲、旗口水母目、游水母科、金黄水母属。因为它的伞体呈现半透明的金黄色,伞体边缘触手呈咖啡色而得名。咖啡金黄水母的触手和口腕很长,在水中展开时像飞天仙女的水袖一般,飘逸洒脱,让人惊叹,因此具有极高的观赏价值。咖啡金黄水母主要生活于日本的白令海,在我国沿海尚未见分布。目前国内大部分水族馆内所有的观赏用咖啡金黄水母都是从国外引进的,因而也     

云南淡水水母一新种（淡水水母目：笠水母科、桃花水母属）

本描记采于云南省路南县黑龙潭水库的桃花水母属一新种－云南桃花水母，新种主辐触手显长于其他触手，缘膜窄，平衡囊呈“S”形管状，刺丝囊集成丛，呈不连续的环状或螺旋状，生殖腺大，三角袋状，黑色，可明显与所有已发现的种相区别。     

台湾海峡软水母亚纲二新种

本文软水母样品系“延平”II号调查船于2007年1月和4月在台湾海峡20º849’~27º056’N，114º920’~121º241’E水域采集的。根据台湾海峡模式标本，本文描述了软水母亚纲二新种：黑背多管水母，新种Aequorea atrikeelis sp. nov. 和波状触丝水母，新种Lovenella sinuosa sp. nov.。兹将二新种主要鉴别特征描述于下： 黑背多管水母，新种：伞扁平，略呈凸透镜形；胃宽约为伞径1/2；口唇23个，简单，片状，口唇数比辐管数少二倍；辐管47条；生殖腺线状，几乎延伸整条辐管；缘触手14条，触手基球宽锥状，有1个背龙骨突，覆盖着黑色素斑块；每二条触手间有3个（2～4）退化缘疣；所有触手基球和缘疣均有向轴排泄乳突；每二条辐管间有1个平衡囊。 波状触丝水母，新种：4个生殖腺线状，生殖腺中线纵向分开两侧，每侧有不规则波状皱褶，生殖腺从垂管近基部沿着辐管到接近环管；4条主辐位缘触手，基球很大，在背轴隆起突出，具黑色素斑块，每个触手基球两侧具有8～10对侧丝；每二条触手间有6～7个退化缘疣和7～8个平衡囊；缘疣无侧丝，疣顶端具黑色斑点。 关键词：软水母亚纲；分类；新种；台湾海峡 中图分类号：Q958.8; S932.8 文献标识码：A     

福州地区发现的一种桃花水母的分类鉴定

采用形态鉴定和18SrDNA基因序列分析技术对采自福州一金鱼养殖场蓄水池中的桃花水母（freshwaterj ellyfish）进行分类鉴定。结果显示：样品的平衡囊管状，主辐触手较其它触手长，刺丝囊疣为乳突状呈螺旋状或环状排列，形态鉴别特征与己知的索氏桃花水母及其亚种相同；触手密集度11．06±0．71，平衡囊密集度5．66±0．43，与索氏桃花水母也最相近；样品18SrDNA序列与GenBank中索氏桃花水母有99％的相似性。因此，经鉴定本次在福州地区发现的桃花水母为索氏桃花水母（Craspedacusta sowerbyi Lankester, 1880）。     

Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean

The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.     

Growth performance,digestive enzyme activity and immune response of Japanese sea bass,Lateolabrax japonicus fed with fructooligosaccharide

In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.     

Protein and amino acid composition from the mantle of juvenile O ctopus vulgaris exposed to prolonged starvation

Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg^?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg^?1 protein) than essential amino acids (425.82 ± 9.15 g kg^?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.     

Involvement of gonadal steroids in final oocyte maturation of white perch (Morone americana) and white bass (M. chrysops): in vivo and in vitro studies

Plasma estradiol-17 (E₂), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E₂ and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E₂ and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass.     

Cardiac,ventilatory and metabolic responses of two ecologically dissimilar species of fish to waterborne cyanide

Changes in heart rate, ventilatory activity and oxygen consumption were determined in trout (Salmo gairdneri) and brown bullhead catfish (Ictalurus nebulosus) during exposure to a steadily increasing concentration of waterborne cyanide selected to produce death in 8–9 hours for each species. The lethal cyanide concentration for the bullheads was an order of magnitude higher than for trout. Trout developed an immediate and gradually increasing bradycardia throughout the exposure period. Cyanide produced tachycardia in the bullhead followed by a gradual onset of bradycardia as the concentration of cyanide was raised. Pericardial injection of atropine (a muscarinic cholinergic antagonist) indicated that bradycardia in the trout was due initially to increased vagal tone but later due to the direct effect of cyanide on the heart. Hyperventilation in the trout persisted throughout the exposure period, although the rate and amplitude fluctuated and was variable between individual fish. During the last hour of exposure (highest cyanide concentration), ventilation was characterized by rapid, shallow breaths followed by a sudden respiratory arrest. The bullheads exhibited hyperventilation during the first 3 hours of exposure followed by a gradual, linear drop in ventilation rate and amplitude until death occurred. Cardiac and ventilatory responses in both species were attributed to stimulation of central and peripheral chemoreceptors by cyanide. Evidence is presented which suggests the initial response in the bullheads was due, at least in part, to gustatory stimulation by the cyanide. Oxygen consumption of the trout remained above pre-exposure levels for the majority of the test period. Oxygen consumption in the bullhead paralleled the changes in heart and ventilatory rates. Whole-body lactate levels of fingerlings of both species during cyanide exposure were measured to estimate the extent of anaerobiosis. Whole-body lactate levels were much greater in the bullheads than the trout, indicating a higher capacity for anaerobiosis, possibly due to a greater fuel supply. Overall, the trout responded to cyanide in a manner similar to that produced by environmental hypoxia whereas the bullheads experienced a gustatory stimulus which masked the hypoxia-like response.     

An overview of stress physiology of fish transport: changes in water quality as a function of transport duration

This study brings an integrated analysis about the relationship between water deterioration and its physiological consequences in live fish transport. The analysis was focused on the transport water and its deterioration, and physiological challenges imposed on the fish. Usual commercial handling procedures employed to mitigate fish stress during transport were discussed. Future topics of research for the establishment of safer fish transport protocols were proposed. Transport was classified into short (≤8 h) or long transport (>8 h). The main issue in short transports should be the prevention of water pH reduction, while in long transports it is the increase in ammonia. Plasma cortisol is the most employed marker for stress and is acutely elevated upon short episodes of transport, but remains elevated even in long‐transport events. Plasma glucose is perhaps a better marker for handling stress. Plasma lactate, pH, osmolality CO₂ and ions should be more often evaluated. Plasma Na⁺ and Cl^‐ are very useful markers of acidosis, due to their respective exchange for H⁺ and , for acid–base regulation. The establishment of species‐specific transport protocols should be preceded by such combined analyses of water and physiological parameters.     

Are hatchery‐reared abalone naïve of predators? Comparing the behaviours of wild and hatchery‐reared northern abalone,Haliotis kamtschatkana (Jonas, 1845)

Abalone populations have declined worldwide, generating interest in enhancement using hatchery‐reared individuals. In many cases, such restoration efforts have met with limited success due to high predator‐induced mortality rates. Furthermore, the mortality rates of outplanted hatchery abalone are often considerably higher than for wild individuals. This study uses northern abalone (Haliotis kamtschatkana) as a case study to determine whether hatchery‐reared abalone behave differently than their wild counterparts. In the field, outplanted hatchery‐reared abalone were significantly less responsive than wild abalone, in terms of number of abalone responding and intensity of response, to nearby movement and to physical contact with an inert probe. Also, when encountering a cue to which all abalone responded (a seastar predator), hatchery‐reared individuals remained subdued. Anti‐predator behavioural deficits in hatchery‐reared abalone were more pronounced in 4‐year‐old individuals than in 1‐year‐old individuals, suggesting an influence of either age or amount of time spent in the hatchery environment. These behavioural differences are expected to increase the vulnerability of hatchery‐reared abalone to predators, and are likely a major cause of their elevated predator‐induced mortality when outplanted.     

Effects of cadmium on the kinetics of calcium uptake in developing tilapia larvae, Oreochromis mossambicus

The toxic effects of Cd²⁺ on Ca²⁺ influx kinetics in developing tilapia (Oreochromis mossambicus) larvae were evaluated. Addition of 20 µg l^-1 of Cd²⁺ to the environment of 0 and 3 day-old larvae competitively inhibited the Ca²⁺ uptake within 4h resulting in a great increase in K_m values for Ca²⁺ influx (19.3 and 17.4 fold, respectively) as compared with their respective controls. Consequently, the actual Ca²⁺ influx of larvae in solutions of 0.2 mM Ca²⁺ are suppressed by 32–45%. Also, 3 day-old larvae were more sensitive to internally accumulated Cd²⁺ than 0 day-old larvae. Although the Ca²⁺ influx in 0 and 3 day-old larvae may be restored to the levels of their respective controls with 24h of being transferred to a 20 µg l^-1 Cd²⁺ solution, total body Ca²⁺ content was significantly reduced in 3 day-old larvae. Increased Ca²⁺ uptake efficiency ensures sufficient Ca²⁺ for normal growth. However, rapid increase in Ca²⁺ influx after hatching also leads to higher Cd²⁺ uptake. Exposure to Cd²⁺ will lead to a drop in body Ca²⁺ content resulting in retardation of larval growth. Therefore, we conclude that if Ca²⁺ uptake is interfered with at this critical stage of development, larvae will not be able to maintain normal levels of body Ca²⁺ and will show signs of Cd²⁺ poisoning.     

Migratory dynamics of stream-spawning longnose gar (Lepisosteus osseus)

Abstract– Literature evidence suggests that lake-dwelling longnose gar (Lepisosteus osseus) enter tributary streams to spawn, Until the present study, the dynamics of this breeding migration had never been investigated quantitatively. During the summers of 1991 and 1992, longnose gar were captured as they entered Weaubleau Creek, Missouri, a tributary of Harry S. Truman Reservoir. The in-stream spawning migration began in early April and ended in late May, and was positively correlated with stream flow and water level, and negatively correlated with water temperature. In-stream residence times ranged from 15 to 94 days, with males exhibiting longer residence times than females. Once in-stream, longnose gar travelled as far as 10 km upstream and occupied certain pools at greater relative frequencies. Although the reason for this preferential utilization is not completely understood, it may relate to pool depth and riffle proximity. Longnose gar disperse from the spawning stream great distances, with gar captured in Weaubleau Creek being recaptured up to 48 km away. This information should provide fisheries biologists the means to consider the reproductive ecology of this species in their conservation and management decisions.     

Nutritional regulation of hepatocyte fatty acid desaturation and polyunsaturated fatty acid composition in zebrafish (Danio rerio) and tilapia (Oreochromis niloticus)

The desaturation and elongation of [1-¹⁴C]18:3n-3 was investigated in hepatocytes of the tropical warm freshwater species, zebrafish (Danio rerio) and Nile tilapia (Oreochromis niloticus). The hepatocyte fatty acid desaturation/elongation pathway was assayed before and after the fish were fed two experimental diets, a control diet containing fish oil (FO) and a diet containing vegetable oil (VO; a blend of olive, linseed and high oleic acid sunflower oils) for 10 weeks. The VO diet was formulated to provide 1% each of 18:2n-6 and 18:3n-3, and so satisfy the possible EFA requirements of zebrafish and tilapia. At the end of the dietary trial, the lipid and fatty acid composition was determined in whole zebrafish, and liver, white muscle and brain of tilapia. Both zebrafish and tilapia expressed a hepatocyte fatty acid desaturation/elongation pattern consistent with them being freshwater and planktonivorous fish. The data also showed that hepatic fatty acid desaturation/elongation was nutritionally regulated with the activities being higher in fish fed the VO diet compared to fish fed the FO diet. In zebrafish, the main effect of the VO diet was increased fatty acid Δ6 desaturase activity resulting in the production of significantly more 18:4n-3 compared to fish fed the FO diet. In tilapia, all activities in the pathway were greater in fish fed the VO diet resulting in increased amounts of all fatty acids in the pathway, but primarily eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3). However, the fatty acid compositional data indicated that despite increased activity, desaturation of 18:3n-3 was insufficient to maintain tissue proportions of EPA and DHA in fish fed the VO diet at the same level as in fish fed the FO diet. Practically, these results indicate that manipulation of tilapia diets in commercial culture in response to the declining global fish oil market would have important consequences for fish fatty acid composition and the health of consumers. Scientifically, zebrafish and tilapia, both the subject of active genome mapping projects, could be useful models for studies of lipid and fatty acid metabolism at a molecular biological and genetic level. This revised version was published online in August 2006 with corrections to the Cover Date.