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1.
The aim of the present work was to investigate the possible use of the clam Tapes philippinarum—a filter-feeding bivalve living on soft bottoms—in the monitoring of sediment pollution in the Lagoon of Venice (North-East Italy). To this end, two clam populations, exposed to different environmental conditions (a relative clean site and an industrial polluted area), have been monitored for the prevalence of the protozoan parasite Perkinsus sp. as well as for several biological parameters commonly used as determinants of contaminants exposure. First results showed a low prevalence, higher in the clean site, but a very diffuse distribution of the parasite throughout the two populations. Nevertheless, greater digestive cells height and longer lysosomal latency time were observed in clams from the clean area. As for the physiological stress-related parameters, even if clearance rates were always higher in these clams, scope for growth values indicated a more complicated biological response. 相似文献
2.
A field study was conducted to assess the potential use of metallothionein (MT) and stress proteins as biomarkers of trace metal exposure. Shore crabs (Carcinus maenas) were collected from five sites: three located in the metal-contaminated Fal estuary (Southwest England) and two control sites located on the south coast of England. Two methods for determining MT levels in crab midgut gland were compared. A direct method in which MT was quantified by spectrophotometric measurement of SH content, and an indirect method in which the metal content (Cu and Zn) of partially purified MT was measured. Stress protein levels (stress-70) were quantified in crab gills using an improved western blotting technique. Elevated Cu and Cd concentrations compared to values in control crabs were found in the midgut glands of crabs from the Fal estuary. No significant variation was seen in Zn concentrations among the five sites. The two techniques used for MT analysis yielded similar results. Metallothionein concentrations were slightly higher in crabs from Restronguet Creek (the most metal-contaminated site) than in crabs from the other four sites, however this difference was not significant (p > 0.05). Stress protein levels did not reflect the metal gradient. 相似文献
3.
Changes in the concentration of lipovitellin, a lipoprotein that is the major protein in mature oocytes of crustaceans, were determined during ovarian development in female blue crabs, Callinectes sapidus. To test the effects of reproductive toxins on vitellogenesis, crabs were fed food containing cadmium or injected with the juvenile hormone antagonist, precocene II. Monoclonal antibodies prepared against one of the lipovitellin peptides (peptide A—107 kDa) were used in an enzyme linked immunosorbent assay to determine lipovitellin concentrations. Recently molted female crabs fed food containing cadmium (0.02 mg/g) for 18 days had oocytes with the same lipovitellin concentration as controls, but after 24 days the oocytes in cadmium treated crabs had significantly lower lipoprotein contents than controls (30 ± 4 ng/oocyte—cadmium treated; 45 ± 4 ng/oocyte—control). Precocene II-treated crabs had significantiy lower lipovitellin concentrations after 18 and 24 days. Diameters of oocytes were the same in both treated and control crabs. The results suggest that some pollutants may affect reproduction by acting during secondary vitellogenesis i.e., period when there is a large increase in lipovitellin synthesis. Since lipovitellins serve many of the nutritional needs of recently emerged crab embryos, poor larval survival may occur as a result of lower lipovitellin content. 相似文献
4.
Thomas K. Sawyer Earl J. Lewis Mark E. Galasso John J. Ziskowski 《Marine environmental research》1984,14(1-4)
Rock crabs, Cancer irroratus, were examined grossly and microscopically to estimate the influence of molting activity, geographical source and seabottom sediments on gill color, carapace color and tissue pathology. Collections were made from deepwater stations (20–55 m) in the Hudson Shelf Valley near dredge- and sewage-sludge disposal sites in the New York Bight apex, and from nearshore waters near Boothbay Harbor, Maine. Extensive gill blackening was noted in up to 30 % of the crabs from the New York stations when all specimens were in the intermolt condition. Blackening was not noted in intermolt crabs collected in Maine. Carapace blackening was present in up to 79 % of the New York crabs but absent in those from Maine. Severe blackening was attributed to direct contact of Cancer irroratus with blackened, highly organic sediments in the Hudson Shelf Valley. Fouling microorganisms on gill epicuticle included bacteria, diatoms, stalked ciliates, amoebae, flagellates and copepods. Bacteria, diatoms, amoebae and flagellates were common on crab gills from both locations. Ciliates and copepods counted in histological sections were considerably fewer in crabs from the New York stations than in those from Maine. Melanized nodules (hemocyte clumps) were present in gill tissue in up to 58 % of the New York crabs and in up to 68 % of Maine crabs. Unidentified microsporidans were found in up to 55 % of the New York specimens and in less than 2 % of those from Maine. Histological data accumulated since 1975 are summarized to provide a list of endoparasites, polychaete worms and barnacles observed in Cancer irroratus from the northeastern United States. Gill blackening, but not parasitism or microbial fouling, proved to be the best indicator or monitoring the effects of ocean dumping on the health of a benthic crustacean species. 相似文献
5.
为解析拟穴青蟹(Scylla paramamosain)血卵涡鞭虫病的流行病学特征,于2012年4—11月采用跟踪监测和实地调查的方法,结合病原分离鉴定及病蟹的病理学观察,统计分析了浙江省温州地区养殖拟穴青蟹血卵涡鞭虫病的流行情况。结果表明,患病拟穴青蟹的肝胰腺、肌肉、鳃等组织病理显示有大量血卵涡鞭虫侵染,并能用PCR方法快速检出。温州地区养殖拟穴青蟹血卵涡鞭虫病在每年5—11月均有发生,7—9月为集中发病时间,死亡高峰出现于8—9月之间,年份间(2010—2012)与发病率无相关性,而不同月份对病害的发生有极显著影响(P0.01)。不同发育阶段以脱壳期的发病率相对较高,发病蟹的规格主要以50g以下的幼蟹和250g以上的成蟹为主。拟穴青蟹血卵涡鞭虫病的发生与水温(r=0.756)和盐度(r=0.631)变化关系较密切,夏、秋季节受梅雨、台风影响而引起水温和盐度的剧烈变化可能是暴发血卵涡鞭虫病的诱发因素。 相似文献
6.
7.
Collection of marine invertebrates for use as fishing bait is a substantial activity in many parts of the world, often with unknown ecological consequences. As new fisheries develop, it is critical for environmental managers to have high quality ecological information regarding the potential impacts, in order to develop sound management strategies. Crab-tiling is a largely unregulated and un-researched fishery, which operates commercially in the south-west UK. The target species is the green crab Carcinus maenas. Those crabs which are pre-ecdysis and have a carapace width greater than 40 mm are collected to be sold to recreational anglers as bait. Collection involves laying artificial structures on intertidal sandflats and mudflats in estuaries. Crabs use these structures as refugia and are collected during low tide. However, the effect that this fishery has on populations of C. maenas is not known. The impact of crab-tiling on C. maenas population structure was determined by sampling crabs from tiled estuaries and non-tiled estuaries using baited drop-nets. A spatially and temporarily replicated, balanced design was used to compare crab abundance, sizes and sex ratios between estuaries. Typically, fisheries are associated with a reduction in the abundance of the target species. Crab-tiling, however, significantly increased C. maenas abundance. This was thought to be a result of the extra habitat in tiled estuaries, which probably provides protection from natural predators, such as birds and fish. Although crabs were more abundant in tiled estuaries than non-tiled estuaries, the overall percentage of reproductively active crabs in non-tiled estuaries was greater than in tiled estuaries. As with most exploited fisheries stocks, crabs in exploited (tiled) estuaries tended to be smaller, with a modal carapace width of 20–29 mm rather than 30–39 mm in non-tiled estuaries. The sex ratio of crabs however; was not significantly different between tiled and non-tiled estuaries. These results illustrate the potential to manage fished populations using habitat provision to mitigate the effects of fishing pressure. 相似文献
8.
Sarah D. Carr Richard A. Tankersley James L. Hench Richard B. Forward Jr. Richard A. Luettich Jr. 《Estuarine, Coastal and Shelf Science》2004,60(4):567-579
Female blue crabs (Callinectes sapidus Rathbun) migrate from low salinity estuarine regions to high salinity regions near the ocean to release larvae. During this migration, ovigerous females use ebb-tide transport, a vertical migratory behavior in which they ascend into the water column during ebb tides, to move seaward to larval release areas. In order to determine the relationship of ebb-tide vertical migrations to local currents and the influence of these vertical migrations on the horizontal transport of blue crabs in the estuary, ovigerous females with mature embryos (1–3 days from hatching) were tracked near Beaufort Inlet, North Carolina (USA), in July and August 2001 and 2002. Crabs were tagged and tracked using ultrasonic telemetry, and currents near the crabs were measured simultaneously with a shipboard acoustic Doppler current profiler.During the two seasons, eight crabs were successfully tracked for periods ranging from 3.9–37.0 h and for distances ranging from 1.9–10.6 km. All crabs migrated seaward during the tracking periods. Crabs moved episodically during all tidal phases with periods of movement on the order of minutes to an hour. They moved with local currents in terms of both speed and direction during ebb tides, consistent with ebb-tide transport, and moved down-estuary (seaward) in opposition to local currents during flood tides. The percentage of time that crabs were active was higher during night ebb tides than during day ebb tides or flood tides and increased with increasing ebb-tide current speed. Mean migratory speeds were 0.11, 0.04, 0.08 and 0.02 m s−1 during night ebb, night flood, day ebb and day flood tides, respectively, and net migratory speeds were on the order of 5 km day−1. Due to the episodic nature of the crabs' movements, the total distances that crabs traveled during ebb tides ranged from 10–40% of the distances that passive particles could have traveled under the same conditions. 相似文献
9.
The purpose of these studies was to evaluate if there were relationships between lysosomal destabilization or glutathione concentrations and gamete viability of oysters, Crassostrea virginica. Oysters were collected from field sites during the peak spawning period (May–June) during 2001 and 2002. Lysosomal destabilization rates and glutathione concentrations of hepatopancreas tissues (e.g. digestive gland) were determined. Eggs and sperm from the same adults were also used to conduct embryo development assays with reference seawater collected from a clean site, site water, and also a range of Cd concentrations (the Cd exposures were used to determine if there were differences in susceptibility to pollutants). Baseline embryo development success (e.g. percent normal development when the assays were conducted with reference seawater or site water) was related to lysosomal destabilization, but not glutathione status. However, the susceptibility of embryos to metal toxicity was related to glutathione status, i.e., sensitivity to Cd exposures increased with decreasing glutathione levels. These studies support the hypotheses that there are linkages between embryo development success and susceptibility to pollutant stress and cellular biomarker responses. These kinds of effects on reproductive success could lead to subtle but significant long-term effects on recruitment and viability of oyster populations. 相似文献
10.
A. Viarengo M.N. Moore G. Mancinelli A. Mazzucotelli R.K. Pipe 《Marine environmental research》1985,17(2-4)
Metallothioneins and lysosomes are known to be involved in cellular detoxication and sequestration of certain metals1–3 and both have been identified in this role in elimination of copper from marine mussels (Mytilus edulis/galloprovincialis).3 Cadmium (Cd), however, has been shown to persist in the cells of the digestive gland for long periods with only minimal elimination. An experiment was designed to test the effects of Cd on the fragility of lysosomal membranes in the digestive cells as a measure of cellular injury,4,5 metallothionein content of the digestive gland and cadmium concentration in this organ. Phenanthrene was used also to destabilise lysosomal membranes6 in order to test if increased lysosomal fragility interfered with cadmium metabolism and detoxication. The results demonstrated that Cd induced metallothionein synthesis and that elimination of Cd was minimal after 28 days in clear seawater. Lysosomal fragility was initially increased but this effect was soon reversed, even with continued exposure to Cd. The lysosomal destabiliser, phenanthrene, did not appear to affect accumulation of Cd or levels of metallothionein. 相似文献
11.
Mangrove ecosystems are sites with high biodiversity of benthic fauna, and fiddler crabs (genus Uca) are common benthic fauna in mangroves. The North Sulawesi in Indonesia has a good condition of mangrove while the information of the fiddler crabs is still limited. Manual samplings were conducted in wet, dry and transient seasons at a mangrove in Kema, North Sulawesi to investigate the species composition, density and distribution pattern of fiddler crabs. A total of 168 individuals, subjected to eight species of genus Uca crabs were collected at the mangrove, with U. triangularis having the highest abundance and U. annulipes having the lowest abundance. The densities of fiddle crabs were 27.56 ind./m2, 32.89 ind./m2 and 14.22 ind./m2 at the seaward, middle and landward zones, respectively, and the density was higher in dry and wet seasons than in transient season. 相似文献
12.
Sara Fratini Lorenzo Zane Lapo Ragionieri Marco Vannini Stefano Cannicci 《Estuarine, Coastal and Shelf Science》2008,79(4):679-686
The “genetic erosion” hypothesis posits that heavy metal stress is related to a loss of genetic diversity at the population level. The genetic diversity of natural populations can, however, be affected by natural processes as well as by human impact. We studied the relationship between heavy metal bioaccumulation and genetic variability in the intertidal crab Pachygrapsus marmoratus. Tissue samples were collected from 40 individuals inhabiting four polluted and four unpolluted sites along the Tuscan coast (Mediterranean basin), and were examined for four heavy metals (arsenic, As, cadmium, Cd, lead, Pb, and copper, Cu). We also assessed the genetic variability of 235 crabs from the same localities using six microsatellite loci.Our results show that the bioaccumulation levels of these individuals accurately reflect the levels of pollution in their immediate environment, and that heavy metals accumulate more in the hepatopancreas than in the gills. Moreover, populations from polluted sites have significantly less genetic variability, measured as mean standardized d2, and a significantly lower percentage of unrelated individuals, than populations from unpolluted sites. This evidence supports the “genetic erosion” hypothesis for metal heavy exposure in natural environments. 相似文献
13.
中华鲎(Tachypleus tridentatus)是保障我国医疗检测安全的重要战略生物资源,国内外中华鲎行为生态学相关研究极少。在实验室内模拟砾石底(NS)、细砂(SS)、中砂(MS)、粗砂(CS)、泥(AR)、泥沙1 (AA)、泥沙2 (AB)和沙泥(SA) 8种不同比例的泥沙类型对中华鲎行为特征的影响。结果表明,稚鲎较多时间潜藏于泥沙中,较少时间裸露于泥沙表面活动(如爬行、游泳等)。稚鲎偏好在含淤泥较多的泥沙类型中潜沙,且在泥质和泥沙质类型中埋栖时间较在沙质中埋栖时间长;在裸露于泥沙表面时,稚鲎相对偏好栖息于沙质底。泥沙环境下稚鲎用于游泳的时间比例高于砾石底。在凌晨、上午、中午、下午、夜晚5个时间段中,稚鲎在夜晚和凌晨活动较活跃。通过揭示不同比例的泥沙类型底质对中华鲎稚鲎行为特征的影响,为野外增殖放流计划的设计与实施、放流适宜地点的选择以及稚鲎人工养殖环境的优化提供科学理论依据。 相似文献
14.
Following the in vivo exposure of dab (Limanda limanda L.) to cadmium chloride, kidney phagocytes were collected and their respiratory burst measured in vitro using chemiluminescence. Fish were exposed to mean measured concentrations of 1.3, 2.7 and 5.5 mg Cd litre−1 (as total cadmium ion) for a total of nine weeks, followed by a three week depuration period in clean sea water. Compared with control fish, the respiratory burst of kidney phagocytes from dab sampled after six weeks was significantly reduced in the 2.7 and 5.5 mg Cd litre−1 treatments (Steel's test, p < 0.05). Significant reductions were observed in the respiratory burst of phagocytes from all cadmium exposed fish compared with control fish after nine weeks (Steel's test, p < 0.05). After a further three week depuration period in clean sea water, the respiratory burst of phagocytes from fish previously exposed to 1.3 and 2.7 mg Cd litre−1 were still significantly less than in the control group (Steel's test, p < 0.05). Muscle tissue cadmium concentrations were also analysed, although there was no clear relationship between the muscle total cadmium levels and kidney phagocyte chemiluminescence. The results are discussed with respect to the possible mechanism(s) of cadmium immunotoxicity in dab and recommendations made for future work. 相似文献
15.
Biomarker responses in Macoma nasuta (Bivalvia) exposed to sediments from northern San Francisco Bay
Ingeborg Werner Swee J. Teh Seema Datta XiaoQiao Lu Thomas M. Young 《Marine environmental research》2004,58(2-5):299
Our study investigates biomarker responses and survival of Macoma nasuta exposed to sediments collected from six locations in northern San Francisco Bay. Biomarkers analyzed were stress proteins (hsp70) in gill, mantle and digestive gland, lysosomal membrane damage and histopathologic lesions. Sediments and clam tissues were analyzed for a comprehensive suite of heavy metals and trace organic pollutants. Sediment grain size and organic carbon content were determined. Clams accumulated metals, polyaromatic hydrocarbons (PAHs) and organochlorine pesticides (aldrin and p,p′-DDT and its metabolites p,p′-DDD and p,p′-DDE). Pearson and Spearman correlation analysis revealed that mortality, hsp70 in gill and histopathologic lesion scores in gonads, and lysosomal membrane damage were significantly correlated with tissue concentrations of DDT and/or its metabolites. Tissue concentrations of metals, in particular nickel, chromium, and copper, were associated with macrophage aggregates in digestive gland and germ cell necrosis. Cadmium was linked to mortality and lysosomal membrane damage. 相似文献
16.
The seasonal variability of leaf litter removal by crabs was observed from May 2006 to April 2007 in a Kandelia candel mangrove forest in Jiulongjiang Estuary, China. Daily average quantities of leaf fall ranged 0.85–3.86 gDW m−2 d−1, with high values in May, August, October and November. The whole-year's leaf fall was 6.48 t ha−1 yr−1 (1.81 gDW m−2 d−1). The standing stock of leaf litter on the forest floor was 7.78 gDW m−2 averaged from the whole year's data, with the lowest value in December (1.23 gDW m−2) and the highest in April (16.18 gDW m−2). Annually averaged removal (consumption on mangrove floor + burial in burrows) rate of leaf litter by crabs was 0.59 gDW m−2 d−1. High seasonal variability was observed in the removal rates of leaf litter by crabs. Removal rates in the winter months (December, January and February) were 0.07–0.09 gDW m−2 d−1, much lower than those in other months with values of 0.59–1.18 gDW m−2 d−1. Annually averaged percentage of leaf fall removed by crabs was 33%, with the highest values in September (reached 76%) and the lowest values in winter months. Of leaf litter removed by crabs, a large proportion was buried by crabs, and only 12% was consumed by crabs on the forest floor. Leaf litter removal rate, consumption rate on the forest floor, percentages of leaf fall and standing stock removed on the forest floor were significantly positively correlated with air temperature, indicating that leaf removal ability by crabs was higher in warm months than in cold months. 相似文献
17.
血卵涡鞭虫是一类主要感染海产甲壳类的致病性寄生性甲藻。近年来,该寄生性病原在我国沿海主要经济蟹类养殖区域流行性发病,给当地蟹类养殖业造成了严重经济损失。为厘清血卵涡鞭虫的生活史形态,了解宿主的病理损伤机制,本文通过血涂片法和HE染色法系统研究了感染过程中该寄生虫的形态变化和宿主的组织病理变化。结果表明,血卵涡鞭虫在感染过程中经历丝状滋养体、单核/双核/多核滋养体、团聚体、蛛网状滋养体、孢子前细胞及孢子等不同生活史阶段。感染导致三疣梭子蟹发生系统性病理变化,肝胰腺、心脏、鳃、肌肉等器官和组织在不同感染阶段均发生相应程度的组织病理变化,主要表现为体细胞破损或坏死、细胞间隙模糊、疏松结缔组织充斥大量寄生虫细胞。最终由于寄生虫在宿主主要器官组织间隙内大量增殖,导致重度感染的梭子蟹器官或组织功能破坏、丧失而死亡。 相似文献
18.
Common dab were fed a casein based diet containing copper at a concentration of 1·4 mg copper kg−1 (dry weight) or a similar diet supplemented with 200 mg copper kg−1. Fish were sampled after 10 weeks and 20 weeks and hepatic and renal copper, zinc and metallothionein concentrations were measured. All hepatic cytosolic copper in test and control fish co-eluted from Sephadex G-75 with metallothionein, as did some of the cytosolic zinc. After 20 weeks there was three times as much of this metallothionein-bound copper in the livers of the test fish compared to the control fish, although metallothionein concentration was little elevated. On the basis of these results it is proposed that cytosolic liver copper concentration or heat stable liver copper concentration can be used as an indication of excess dietary copper in the dab Limanda limanda. 相似文献
19.
血卵涡鞭虫(Hematodinium spp.)是一类严重危害海洋甲壳类动物的新型寄生性病原,可引发养殖三疣梭子蟹“牛奶病”,导致梭子蟹大量死亡,造成巨大经济损失。目前,对于血卵涡鞭虫在日照养殖梭子蟹中的流行发生情况还未见报道,2020年8月和2021年5～11月期间在日照主要梭子蟹养殖区开展流行病学调查研究,通过形态学观察、组织病理检测和分子生物学鉴定发现了血卵涡鞭虫(Hematodinium perezi)在日照地区的流行分布,并发现其流行病发生在6～9月间,高发期为7～8月,感染率高达52.5%。感染宿主的血淋巴和心脏、肝胰腺、鳃、肌肉等组织中发现了丝状滋养体、类变形虫滋养体、蛛网状滋养体、团块状聚合体、孢子前细胞和孢子等血卵涡鞭虫的多个生活史阶段。在养殖池塘环境水体中检测到血卵涡鞭虫存在,水体中血卵涡鞭虫丰度与宿主感染率存在错峰现象,间隔3～4周。流行病的发生与水体温度和盐度变化密切相关,7～8月较高的水温(26.2～28.6°C)促进了血卵涡鞭虫在宿主体内快速增殖及流行病爆发,而较低的盐度(20.7～25.3)可能抑制了环境水体中血卵涡鞭虫的存活及其传播扩散。以上研究结果初步... 相似文献
20.
Seasonal abundance, distribution and recruitment of mud crabs (Scylla spp.) in replanted mangroves 总被引：3，自引：0，他引：3
Mark E. Walton Lewis Le Vay Junemie H. Lebata Joseph Binas Jurgenne H. Primavera 《Estuarine, Coastal and Shelf Science》2006,66(3-4):493-500
The abundance and distribution of mud crabs were studied in a replanted mangrove forest in Buswang, Aklan, Philippines. Two fishing gears, lift nets and bamboo traps, were used to monitor relative abundance of Scylla spp. populations from March 2002 to December 2003 inside the mangrove forest. A third gear, a stakenet set across a creek, was used to monitor crabs migrating out of the mangroves during the ebb tide. Scylla olivacea formed 99.3% and 70.3% of the catch in the mangrove and the stakenet, respectively. The percentage of Scylla tranquebarica increased from <1% in the mangrove catches to 29% in the stakenet. Scylla serrata was present at very low levels in both catches. The lack of modal progression in the size–frequency plots and the year-round catch rate of gravid females suggested that recruitment was constant throughout the year. Even though relative abundance decreased over the study period indicating that the stock is being over-exploited, mud crab production is more than equivalent to that of most natural mangroves. 相似文献