江苏骆马湖湿地鸟类资源及其保护

新沂骆马湖湿地有鸟类246种,其中44.7%为雀形目鸟类,52.8%为旅鸟。就骆马湖鸟类资源的保护提出四点建议。     

滨湖地区旅游发展与规划策略研究—以宿迁环骆马湖地区为例

分析滨湖地区旅游规划的相关理论和国内外研究开发实践,以宿迁环骆马湖地区为实证研究,探索滨湖地区休闲度假旅游的规划途径与策略。首先分析环骆马湖片区发展旅游的优势与劣势,有针对性地提出规划策略：即以水资源保护为前提,充分依托现有资源条件和市场需求,提出该地区旅游发展定位并塑造品牌旅游产品;合理进行空间布局,因地制宜梳理城湖空间关系,完善“外联、内环、慢体验”的交通方式,以保障宿迁环骆马湖地区的旅游发展。     

丹江口水库鱼类群落特征及其历史变化

为了解丹江口水库鱼类群落现状及历史变化, 作者于2018-2019年采用多网目复合刺网采样和渔民渔获物调查的方式对丹江口水库进行了鱼类群落调查。本次调查共采集鱼类33种, 隶属5目11科29属, 以鲤科鱼类为主, 占总数的63.6%。基于多网目复合刺网采样的鱼类群落多样性指数和单位努力捕捞量(catch per unit effort, CPUE, g·day ^-1·m ^-2)在各采样点间具有一定的差异。目前丹江口水库以定居性、喜静缓流、杂食性和肉食性鱼类为主。与20世纪50年代和80年代的历史资料相比, 丹江口水库鱼类物种丰富度先升高后下降; 而生态类型则呈现杂食性鱼类、喜流水性鱼类和洄游性鱼类比例持续下降的趋势。2018-2019年丹江口水库鱼类组成与20世纪80年代的相似性指数为0.35 (中等不相似), 与20世纪50年代的相似性指数为0.29 (中等不相似)。调查结果表明半个世纪以来丹江口水库鱼类群落结构发生了较大变化, 目前趋于小型化和简单化。这些变化可能是由大坝建设、渔业放养、不合理捕捞、外来鱼类引入等人类活动所致。     

永兴岛附近海域珊瑚礁鱼类群落结构特征

为更好地保护和管理西沙永兴岛附近海域珊瑚礁鱼类,于2020—2021年对永兴岛上岸渔获物进行了调查研究,分析了鱼类群落结构组成及其变化和演替特征。结果表明:调查共发现永兴岛附近海域珊瑚礁鱼类101种,隶属于5目21科,以鲈形目鱼类最多,占总种类的84.16%,生物量超总渔获物的90%;科级水平鹦嘴鱼科鱼类最多,达21种,生物量超总渔获物的45%。28种珊瑚礁鱼类是永兴岛附近海域主要捕捞对象,占总渔获物的80%以上。永兴岛附近海域珊瑚礁鱼类呈现过度捕捞,一是主要渔获物中的中大型鱼类均重偏小;二是本海域个体体型最大的鱼类出现较多消亡;三是肉食性鱼类大量消亡;四是植食性鱼类生物量占比超过了肉食性鱼类。永兴岛附近海域珊瑚礁鱼类已经演替到以植食性鱼类为主导的生态系统;大量海胆的出现,表明了这一珊瑚礁生态系统在进一步衰退,向以海胆为主导的生态系统演变。保护西沙永兴岛附近海域珊瑚礁鱼类已经刻不容缓,需要严格地控制本海域的捕捞强度。     

江苏典型水域湖鲚食性对比分析

利用多目刺网于2017年9—11月在江苏典型水域长江南京段、高邮湖、洪泽湖、骆马湖及淮河江苏段采集湖鲚样品。通过胃含物鉴定以及测定摄食率、平均饱满指数、食物选择指数等指标,对比分析不同水域湖鲚的食性差异。结果表明:不同水域湖鲚皆为浮游动物食性,以枝角类和桡足类为主,偶尔出现轮虫和小型鱼虾;在摄食强度、食物选择性不同水域湖鲚并无显著性差异,但在食物组成上差异明显;洪泽湖湖鲚食物种类最多,高邮湖次之,长江最少;长江、洪泽湖、骆马湖水域湖鲚食物中,桡足类占优势,高邮湖中枝角类占优势;桡足类中,长江、高邮湖、洪泽湖水域湖鲚食物中以剑水蚤为主要优势种(数量百分比为29.2%～70.1%),骆马湖则以刺剑水蚤为主要优势种(数量百分比45.4%),淮河以剑水蚤、温剑水蚤为优势种(数量百分比18.6～18.9%);枝角类中高邮湖、洪泽湖、骆马湖、淮河水域湖鲚食物中象鼻溞为主要优势种,数量百分比76.9%～100.0%,长江水域湖鲚则以溞为主(数量百分比81.5%)。聚类分析表明,根据食性差异,5个不同水域湖鲚可以归为长江种群、高邮湖洪泽湖种群以及骆马湖淮河种群3个种群。     

金鱼的变色培育技术

金鱼是世界闻名的观赏鱼类,不仅供观赏,而且又是从事研究生物遗传进化,鱼类毒理学等方面理想的材料鱼。金鱼与其它鱼类一样,刚孵出的鱼苗并不具备鲜艳的色彩,需经过人工的培育,金鱼约需80天始变色。刚出膜的鱼苗呈银灰色,一个月左右体色才渐变深,再经一段时间的培育,体色渐呈鲜艳色彩,从金鱼的苗种直至成鱼饲养阶     

嗜水气单胞菌疫苗

嗜水气单胞菌Aeromonas hydrophila是引发其爆发性败血症的主要细菌性病原之一,自20世纪80年代末在我国南方出现并引起了许多种淡水养殖鱼类爆发性死亡以来,一直频繁地在许多养殖鱼类中发生。目前对嗜水气单胞菌病的治疗药物主要为抗生素,大量长期使用易产生耐药株。所     

兴凯湖大银鱼食物组成与食性转化

该文于2010年6月—2011年1月逐月分析中俄界湖兴凯湖外来种大银鱼食性,结果发现,大银鱼主要摄食枝角类、桡足类、虾类和鱼类。6月份大银鱼体长<60 mm,以枝角类和桡足类为食,7月份体长>60 mm群组、8月份体长>80 mm群组、9月份体长>100 mm群组与10月及之后体长>120 mm群组等的食谱中均出现鱼类,且优势种类为大银鱼和属鱼类。该摄食鱼类的大银鱼最小体长随季节而增加的现象,与饵料鱼类生长导致的食物资源可得性变动密切相关。     

长江上游中华沙鳅食性特征的C、N同位素分析

应用C、N稳定同位素技术并结合肠含物分析对我国长江上游特有鱼类中华沙鳅（Sinibotia superciliaris）不同发育阶段食性进行了探究。结果显示:中华沙鳅13C、15N平均值分别为（22.480.85）、（10.090.69）;不同体长段13C（P0.05,F=2.44）、15N（P0.01,F=6.06）值差异显著,暗示了中华沙鳅在生长发育过程中存在食性转变现象;体长80 mm的个体主要摄食水生昆虫和藻类,属杂食偏肉食性鱼类;体长80 mm的个体,其食物以虾类、淡水壳菜和水生昆虫为主,属肉食性鱼类。中华沙鳅营养级位于2.02-2.47,与长江上游多种底栖型鱼类生态位相似;食物竞争可能是导致其摄食强度弱和资源量下降的原因之一。研究结果可为长江上游中华沙鳅野生资源保护提供理论参考。     

柳江鱼类群落结构及多样性研究

为了解柳江鱼类群落结构、多样性及其与环境因子的关系, 2018年7月和12月在柳江9个江段(榕江、从江、融安、柳城、象州、永福、鹿寨、河池和宜州)开展鱼类和环境调查。共采集鱼类36474尾, 隶属于5目20科80属115种; 其中, 鲤科鱼类最多(68种), 占59.13%。Shannon-Wiener多样性指数、Simpson指数、Pielou均匀度指数和Margalef丰富度指数的变化范围分别为2.13—3.12、0.81—0.93、0.58—0.80和4.65—7.18。鱼类优势种以银Squalidus argentatus、大眼华鳊Sinibrama macrops、胡Microphysogobio chenhsienensis、银鲴Xenocypris macrolepis和南方拟?Pseudohemiculter dispar等小型鱼类为主。丰度/生物量比较曲线表明, 宜州、榕江、鹿寨、柳城、象州和融安江段鱼类群落受到中度或严重干扰, 河池、从江和永福鱼类群落结构相对稳定。采用非度量多维标度排序(NMDS)方法对鱼类群落的时空分布特征进行分析, 将鱼类划分为3个类群: 柳江上游的从江-榕江类群, 洛清江支流的永福-鹿寨类群, 柳江中下游及龙江支流的融安-柳城-象州-河池-宜州类群。采用典范对应分析(CCA)分析鱼类群落与环境因子的关系, 发现河宽、海拔和pH是柳江鱼类群落结构差异的主要影响因子。与历史资料相比, 柳江鱼类群落结构发生显著变化, 经济鱼类占比减少, 鱼类个体呈现小型化和低龄化。建议从以下几个方面加强柳江鱼类多样性保护: 加强执法力度, 严厉打击偷捕、电捕等非法行为; 对主要经济鱼类开展增殖放流; 恢复河流的连通性; 对流域珍稀特有鱼类进行监测、救护和繁育。     

Effect of dietary ascorbic acid on growth and non-specific immune responses of tiger puffer, Takifugu rubripes

We report nutritional physiology and non-specific immune responses of ascorbic acid (AA) in puffer fish for the first time. This study aimed to examine the essentiality and requirements of AA in diets for the tiger puffer, Takifugu rubripes based on growth performance, liver AA and bone collagen concentration, and non-specific immune responses. Five casein-gelatin based semi-purified diets were formulated to contain five graded levels of l-ascorbyl-2-monophosphate at 0, 40, 80, 160 and 700mg/kg (designated as AMP0, AMP40, AMP80, AMP160 and AMP700, respectively) and fed to triplicate groups of fish. After 10weeks of feeding trial, growth performances of fish (initial body weight, 35g) fed the AMP0 were significantly lower compared to that of fish fed diets supplemented with AMP. The fish fed the AMP0 diet also exhibited significantly lower hematocrit, condition factor and hepatosomatic index compared to the fish fed diets supplemented with AMP. Phagocytic activity (NBT assay) was significantly lower in fish fed the AMP0 diet than in fish fed the AMP containing diets. Plasma lysozyme activity of fish fed the AMP80 and AMP160 was significantly higher than that of fish fed the AMP0. Dietary supplementation of AMP significantly increased the liver superoxide dismutase in the fish. Myeloperoxidase activity of fish fed the AMP0 was significantly lower compared to that of fish fed the AMP containing diets. Bone collagen level tended to increase numerically and total AA concentration in liver of fish was significantly increased in a dose dependent manner by the supplementation of AMP. Therefore, tiger puffer requires exogenous ascorbic acid and the optimum dietary level could be 29mg AA/kg diet for normal growth and physiology. Dietary AA concentration over 82mg/kg could be required to enhance non-specific immune responses of the fish. However, it does not seem that the fish needs an overdose of dietary AA (>160mg/kg) for better non-specific immune responses.     

Effects of vegetable feed ingredients on bone health in Atlantic salmon

The aim of the present study was to examine if dietary inclusion of vegetable lipids (VL) and proteins (VP) influenced markers of bone health in Atlantic salmon. Triplicate groups were fed one of four different diets; 100% fish protein (FP) and fish lipids (FL) (FPFL), 80% VP and 35% VL (80VP35VL), 40% VP and 70% VL (40VP70VL), or 80% VP and 70% VL (80VP70VL) for 12 months on‐growth in sea water. Fish were analyzed for vertebral bone mineralization (mineral content, as % of bone dry weight), vertebral deformities (radiology), vertebral bone mRNA expression of factors involved in mineralization (bone gla protein, bgp) and growth regulation (igf‐I and growth hormone receptor), as well as plasma vitamin D metabolites. The fish grew from 0.35 to 4 kg during the experimental period. At the end of the experiment, significantly lower prevalence of fish with one or more deformed vertebrae was observed in the 80VP70VL group (11%) compared to the other groups (33–43%). There was a significant higher relative expression of igf‐I mRNA in vertebral bone of fish fed the 80VP70VL diet compared to control fish (FPFL), while the other genes studied were unaffected. Elevated plasma 25‐hydroxyvitamin D₃ recorded in the marine feed group is discussed as a predictor for later development of bone deformities. In conclusion, the present study shows that high inclusion levels of vegetable lipids and proteins may have a positive effect on bone health in Atlantic salmon postsmolts.     

Nutritional value and mercury content of fish silage for growing pigs

The dry matter content of 18 samples of fish silage prepared from fish species or prawn offal varied from 190 to 274 g/kg (mean 239). Chemical composition (mean and range, g/kg dry matter) was: crude protein 686 (487–882); ether extract 100 (53–211); ash 163 (105–319); and total mercury 1.05 mg/kg (0.24–4.05 mg/kg).The nutritional value of fish silage, prepared from Ocean perch and Nannygai, was investigated for grower pigs. Wheat-based diets were formulated in which fish silage partially or completely replaced soya been meal as the protein supplement. The diets were evaluated over the 20 to 45 kg growth phase. Half the pigs were slaughtered at 45 kg live weight; the remainder were fed on the wheat and soya bean meal diet to 80 kg live weight in order to observe the effect of withdrawal of fish silage at 45 kg on subsequent growth performance and mercury content in the lean tissue.The addition of fish silage improved growth rate (P < 0.05) and food conversion ratio (P < 0.01) during the 20 to 45 kg growth phase. No adverse effects on carcass quality were observed. During the 45 to 80 kg growth phase, when all pigs were fed on the wheat and soya bean meal diet, all produced similar performance. Over the 20 to 80 kg growth phase, the beneficial effects of fish silage on growth rate and feed conversion were maintained.Methyl mercury content in the semi-membraneous muscle of pigs fed on fish silage and slaughtered at 45 kg live weight was 0.085 mg/kg on a wet weight basis. This decreased to 0.018 mg/kg in pigs that had the fish silage withdrawn from the diet during the 45 to 80 kg growth phase.     

Anesthesia of fish with benzocaine does not interfere with comet assay results

Fish blood erythrocytes are frequently used as sentinels in biomonitoring studies. Usually, fish blood is collected by painful cardiac or caudal vein punctures. Previous anesthesia could decrease animal suffering but it is not known at present whether anesthesia can cause confounding effects. Therefore, using the alkaline single cell gel (SCG)/comet assay with blood erythrocytes of the cichlid fish Nile tilapia, we tested for a possible modulation of induced DNA damage (methyl methanesulfonate; MMS) by the anesthetic benzocaine administered by bath exposure (80mg/l for approximately 10min). Furthermore, benzocaine (80-600mg/l) was tested for its genotoxic potential on fish erythrocytes in vitro and for potential interactions with two known genotoxins (MMS and hydrogen peroxide). Our results did neither indicate a significant increase in the amount of DNA damage (even after a 48h follow-up), nor indicated interactions with MMS-induced DNA damage when fish were exposed to benzocaine in vivo. There was also no increase in DNA damage after in vitro exposure of fish erythrocytes to benzocaine. Clear concentration-related effects were observed for the two genotoxins in vitro, which were not significantly altered by the presence of benzocaine. These results suggest that anesthesia of fish does not confound comet assay results and the use of blood samples from anesthetized fish can be recommended with regard to animal welfare.     

Toxicity of Karlodinium micrum (Dinophyceae) associated with a fish kill in a South Carolina brackish retention pond

A dinoflagellate bloom was found associated with a fish kill event in a South Carolina brackish water retention pond. A multi-analytical approach was used to confirm the identity of the bloom dinoflagellate and evaluate its potential toxicity. Karlodinium micrum was confirmed through light microscopy, pigment profile comparisons, species-specific PCR, and gene sequence data. Necropsy findings on several fish were suggestive of an acute kill event. Toxicity of filtrate from bloom samples was tested by a hemolytic assay using rainbow trout (Oncorhynchus mykis) erythrocytes and an ichthyotoxicity assay using larval zebrafish (Danio rerio). Hemolytic activity was measurably high (>80% hemolysis) in both whole filtrate and fractionated filtrate (from the 80% MeOH C₁₈ column elution). This fraction also demonstrated high ichthyotoxic activity as exposed fish experienced rapid death. These results implicate toxic K. micrum as a causative factor in fish death in a non-aquaculture brackish pond associated with a housing development, and extend recent findings linking this species to fish kills in aquaculture ponds.     

Erythrocyte supply from the spleen of exercised carp

• 1.1. Weight and hemoglobin content of the spleen of 3-year-old carp under the resting condition showed seasonal change, and those in male fish were larger than those in females at any season.
• 2.2. Weight of the spleen of 3-year-old fish of both sexes (examined in August and October) and immature fish (examined in September) showed a decrease of more than 50% during severe exercise for 60 min. Hemoglobin content per unit body weight of the same fish showed a decrease of more than 80% with the same exercise.
• 3.3. Hematocrit value and hemoglobin concentration of the blood elevated 41 and 25%, respectively, in the 3-year-old male fish, and 20 and 11%, respectively, in the 3-year-old females during the exercise for 60 min.
• 4.4. Fifty percent and 30% of the hematocrit elevations are considered to have been caused by erythrocyte supply from the spleen in the male and female fish, respectively, and 80% of the elevations in the fish of both sexes can be explained by erythrocyte supply, erythrocyte swelling and water shift out of the blood vessel.

     

Ontogeny of haemoglobin polymorphism in cod

Haemoglobins of 0-group cod from 30 to 150 mm length were analysed by agar gel electrophoresis and isoelectric focusing to identify the lower size limit for determination of the haemoglobin polymorphisms in cod; both the main system which has been known for more than 30 years and the recently described subgroups. The juvenile fish studied had higher concentration of the HbII-component (split into three bands at these fish sizes) compared to older fish. The main haemoglobin types could be distinguished clearly and reliably at a fish size of about 35 mm and above. The subgroups of the HbI-components, however, could not be identified reliably until the cod were about 80 mm.     

Swimming performance of juvenile white sturgeon (Acipenser transmontanus): training and the probability of entrainment due to dredging

White sturgeon, Acipenser transmontanus (Richardson), are at risk of entrainment from dredging, with young-of-the-year fish at greatest risk. To evaluate this entrainment risk, swimming performance trials were conducted in a laboratory swim tunnel with hatchery-reared juvenile white sturgeon with varying experience levels including: naïve (only tested once), tested (re-tested after being kept in no flow) and trained (re-tested after kept in flow for nearly three weeks). Individuals of various sizes (80–100 mm TL) and all experience levels were strongly rheotactic (> 80%), but endurance was highly variable among fish. Small juveniles [< 82 mm total length (TL)] had lower escape speeds (< 40 cm s⁻¹) than medium (82–92 mm TL) and large (> 93 mm TL) naïve fish (42–45 cm s⁻¹), all of which had lower escape speeds than trained fish (72 cm s⁻¹). Behavior was also highly variable among fish. Overall, benthic station-holding behaviors were least frequent in small fish, intermediate in medium and large fish, and most frequent in trained large fish. Probability of entrainment of juvenile white sturgeon can be reduced by maintaining dredge head flow fields at less than 45 cm s⁻¹ for wild-spawned fish or by rearing hatchery fish to > 93 mm TL and exposing the fish to moderate flow velocities (10–12 cm s⁻¹) prior to their release.     

The importance of sculpin (Myoxocephalus scorpius) as intermediate host and transmitter of the sealworm Pseudoterranova decipiens.

A total of 186 sculpins (Myoxocephalus scorpius) were caught at Vega, Nordland, Norway, and examined for sealworm larvae (Pseudoterranova decipiens). Over 80% of the fish were infected. Very high infections were found with a maximum of nearly 300 larvae in one sculpin. Infections of this magnitude have so far not been reported from sculpins or any other fish species of this size. The importance of the sculpin in the life cycle and in the transmission of P. decipiens to seals or other fish species is briefly discussed.     

几种鱼类线粒体ATP酶活性的比较研究

本文比较了草鱼(Ctenopharyngodon idellus)瓦氏雅罗鱼(Leucisous waleckii)和鲮鱼(Cirrhinus molitorella)在常、低温驯养时,肝细胞线粒体ATP酶活性;并采用吐温80处理线粒体,观察其对线粒体ATP酶活化能Arrhenius图折点温度的影响,讨论了线粒体ATP酶活性与鱼类低温适应能力的相关性。认为鱼类线粒体ATP酶活化能折点温度在常、低温驯养时的差异程度和鱼的抗寒性能有关;低温驯养时,线粒体ATP酶活化能折点温度的高低和鱼的低温耐受能力有关。