文昌鱼鳃骨条的透射电镜观察

应用透射电子显微镜观察了文昌鱼（Branchiostoma belcheri tsingtauense Tchang et Koo)鳃骨条的结构。发现其鳃条骨条横切面的外部，有时可见两个相连的细胞密集区，细胞排列紧密，核质比大。除此之外的基质区，由平均直径28．3nm的粗纤维构成。在该区域的外围，粗纤维与边缘平行排列成薄层。在内部，粗纤维交错排列。而鳃条骨条横切面内部及整个舌条骨条则是由平均直径分别为13．8nm和13．9nm的细纤维构成的。细纤维排列规则，与鳃骨条的长轴平行。且彼此间由横向的细丝状交联连接成为直角的方格结构。两种纤维在形态上与胶原纤维不同。显示文昌鱼的鳃骨条是一种特殊的、非胶原为基质的支持组织。这使得继无颌类七鳃鳗和盲鳗中已发现的至少4种非胶原为基质的软骨家族又增添了新的成员，且文昌鱼鳃骨条与七鳃鳗和盲鳗的非胶原为基质的软骨结构都不相同，提示文昌鱼与无颌类可能有着长期独立的进化历史。     

中国蛤蜊鳃的光镜与扫描电镜观察

用光镜和扫描电镜观察了中国蛤蜊鳃的组织学和表面结构。所有鳃丝的组织结构均相同。鳃丝上皮按结构与功能可区分为4个区带：前纤毛柱状细胞区、侧纤毛柱状细胞区、粘液细胞区和扁平细胞区。前纤毛和侧纤毛分别与食物的运送和呼吸水流的产生有关。扁平细胞为呼吸上皮，其结构有助于气体交换。相邻鳃丝通过成排的、含有血管的丝间连接连系。     

Characterization of Ca-ATPase activity in gill microsomes of freshwater mussel, Lamellidens marginalis (Lamarck) and heavy metal modulations

Freshwater mussel Lamellidens marginalis showed a Ca²⁺-stimulated ATPase activity in the microsomal fraction of gill. Mg²⁺ was also found to be an activating cation for this ATPase enzyme. Ca²⁺ ATPase showed maximal activity at 40 °C and between pH 7.5–8.0. Substrate specificity of Ca²⁺ ATPase was highest with ATP, followed by GTP and other trinucleotides such as UTP, CTP and ADP also showed some amount of hydrolysis. Ca²⁺ ATPase showed slight inhibition with ruthenium red and sodium vanadate and is insensitive to sodium azide, ouabain, oligomycin B and phenylalanine. Heavy metals like Hg²⁺, Cu²⁺ and Zn²⁺ showed 50% inhibition of Ca²⁺ ATPase activity at concentrations of 0.25 mM, 0.5 mM and 1 mM, respectively whereas Cd²⁺ and Ni²⁺ showed 39% and 28% inhibition of enzyme activity at 1 mM concentrations.     

溶解氧对团头鲂耐低氧新品系F5代的鳃组织形态及各组织酶活性的影响

为研究不同浓度溶解氧(DO)对团头鲂(Megalobrama amblycephala)耐低氧新品系F5代鳃组织形态以及各组织酶活性的影响,本研究将团头鲂在低氧[DO为(1.7±0.2) mg/L]和高氧[DO为(19.3± 0.5) mg/L]条件下分别处理0、4和7 d,恢复常氧[DO为(7.8±0.3) mg/L] 7 d后,通过石蜡切片观察鳃组织的形态,并测定了鳃、肝胰腺、肠道、肌肉中过氧化氢酶(CAT)、琥珀酸脱氢酶(SDH)及乳酸脱氢酶(LDH)活性和丙二醛(MDA)含量。石蜡切片结果显示,随着低氧处理时间的延长,团头鲂新品系鳃丝的层间细胞团体积减小,鳃小片表面积增加,恢复常氧7 d后又有所恢复。高氧条件下,层间细胞团体积增大,鳃小片表面积减小,恢复常氧7 d后也会恢复。酶活性检测结果显示,在低氧和高氧2种条件下,随着处理时间的延长,CAT活性和MDA含量在各组织中的变化无明显规律,但均有显著差异(P<0.05)。低氧条件下,LDH活性显著增高,SDH活性显著降低(P<0.05)。高氧条件下,LDH活性显著降低,SDH活性显著增高(P<0.05)。本研究可为溶解氧对团头鲂的鳃组织以及各组织酶活性的影响提供基础资料,并为团头鲂新品系的养殖与选育奠定基础。     

两种(鱼叚)虎鱼染色体核型的比较研究

本文采用脾脏细胞空气干燥法制片,Giemsa染色,对两种生活于近海沿岸的(鱼叚)虎鱼染色体核型进行分析研究。其中,纹缟(鱼叚)虎鱼(Tridentiger trigonoce phalus)2n=44,NF=76,有10对中部着丝点染色体,6对亚中部着丝点染色体和6对端部着丝点染色体;竿(鱼叚)虎鱼(Luciogobius guttatusGill)2n=44,NF=72,有7对中部着丝点染色体,7对亚中部着丝点染色体和8对端部着丝点染色体。未发现有异形染色体。     

草鱼细菌性烂鳃病病原的研究

从患细菌性烂鳃病的草鱼病灶分离得滑动细菌M_(165),经多次水中感染(及反复分离、再感染),能使草鱼及多种池塘鱼类显症、死亡。M_(165)的生物学特性与鱼害粘球菌相似,但不能用Dworkin法快速诱生小孢子。该菌DNA碱基比为35.3％,与粘球菌有明显差异,采用柱状屈桡杆菌学名Fiexibacter columnaris (Davis)Leadbetter。     

Histopathology of respiratory organs of certain air-breathing fishes of India

Air-breathing fishes have evolved bimodal respiratory mechanisms for exploitation of water (through gills and highly vascularized skin) as well as atmospheric air (through aerial respiratory organs, ABO). Mucous cells in these respiratory organs of variously stressed fishes exhibit periodic fluctuations in their density and staining properties. The main types of damage in the gills include congestion of blood capillaries (BLCs), periodic lifting and sloughing of respiratory epithelia of the secondary lamellae causing haemorrhage, extensive fusion of secondary lamellae and hyperplasia of the respiratory epithelia due to uncontrolled regeneration leading to asphyxiation, altered excretion, and death of the fish. Haemolysis has also been observed following lead exposure. The damage in the ABO of Heteropneustes fossilis includes sloughing of the epithelial cells, leading to haemorrhage causing decreased red blood corpuscles density and degeneration of the secondary gill lamellae with reduced respiratory area. Subsequent hyperplasia of the respiratory epithelia and fusion of gill lamellae increase the respiratory barrier distance. The BLCs often bulge out and protrude into the lumen, bringing blood nearer to air. The ladder-like pillar cell (PLC)-BLC components of the gill lamellae frequently collapse. Damage to the ABO of Channa striata is less severe. Often haemorrhaging due to bursting of extensively stretched BLCs causes aerial respiratory failure. Chloride cells of the ABOs also show hyperplasia. While the highly mucogenic epidermis of C. striata shows less damage, the epidermis of Clarias batrachus and H. fossilis shows severe wear and tear, sloughing, and haemorrhage. Side-by-side regeneration continues, causing altered histomorphology of the epidermis. The different gland cells also show periodic fluctuations in their density and staining. The dermis also shows severe damage with loosening of their connective tissue fibres. These fibres give stronger reactions for sulfated mucin that not only retain additional water molecules for continuance of skin breathing, but also bind the toxic ambient pollutants.     

酸碱胁迫对奥尼罗非鱼幼鱼鳃组织结构及Na~+-K~+-ATP酶活力的影响

[目的]探讨酸碱胁迫对奥尼罗非鱼幼鱼鳃组织结构及Na~+-K~+-ATP酶活力的影响。[方法]将初始体质量(6.81±0.85)g奥尼罗非鱼(Oreochromis aureus×Oreochromis niloticus)幼鱼暴露于不同酸碱度(p H分别为4.5、6.0、7.5、9.0、10.5,依次设为试验Ⅰ、Ⅱ组、对照组及试验Ⅲ、Ⅳ组)的水体中,每组3个重复,每个重复30尾鱼。胁迫后0、12、24、48、72 h采集鱼鳃样本,采用HE染色石蜡组织切片及分光光度法比较酸碱胁迫对鱼鳃组织结构及其中Na~+-K~+-ATP酶活力的影响。[结果]对照组鱼鳃的组织结构未发现有明显病变的症状,且鳃中的Na~+-K~+-ATP酶活力维持在一定水平;各胁迫组鱼鳃组织结构均不同程度发生病变,出现鳃丝融合,动脉血管破损,鳃小片肿胀弯曲,顶端与末端粘充血和肿胀,黏液细胞增多,上皮细胞增生、脱落,泌氯细胞肿胀,细胞质空泡化等一系列病态症状,且其症状会随着酸碱程度的加深、暴露时间的延长而加重;酸碱胁迫后各胁迫组鱼鳃中Na~+-K~+-ATP酶活力均出现先升高后降低的变化,其中酸胁迫的峰值出现在48 h,而碱胁迫出现在12 h。[结论]该研究结果可为奥尼罗非鱼的养殖生产提供理论依据。     

Groundwater water treatment for iron and manganese reduction and fish rearing studies applied to the design of the Ruth Burnett Sport Fish Hatchery, Fairbanks, Alaska

Studies at the Fairbanks Experimental Fish Hatchery (FEFH) were conducted to investigate the operational characteristics of media filtration groundwater treatment for iron and manganese reduction, water reuse and recirculation technologies for fish rearing, and conditions of fish gill tissue during rearing. Results were used to aid in the design and planned operation of the Ruth Burnett Sport Fish Hatchery (RBSFH), currently under construction in Fairbanks, Alaska. Under a two-stage filtration scenario, with hydraulic loading rates of 0.39 and 0.43 cm/s for Stages 1 and 2, respectively, manganese dioxide media filtration typically removed dissolved iron from 5 to 6.5 mg/L down to 0.1 mg/L or less, and allowed for suitable fish rearing and health (based on gill condition) in treated groundwater. Poor water quality from filter equipment malfunction or improper operation typically manifested tissue damage (epithelial lifting, hypertrophy, degeneration, and in some cases iron adhesion) observed in fish gills. Design refinements from initial use, including changes in hydraulic loading rates and transition from single-stage to two-stage filtration, were required for long-term use of media filtration and were included in the design of the future hatchery. Dissolved manganese removal from groundwater (from 0.7 to <0.05 mg/L) was also implemented by continuous low-level potassium permanganate addition. Small-scale flow-through, fully recirculating, and partial reuse rearing systems were used to mimic planned future fish production, and resulted in 97% or greater survival and adequate growth (average specific growth rate between 1 and 2%) and health of rainbow trout during most rearing trials.