乌江下游干流鱼类物种多样性及其资源保护

为摸清乌江下游干流现有的鱼类种类组成和物种多样性状况, 探索水电开发对鱼类群落多样性的影响, 本研究于银盘电站蓄水前的2006-2008年和蓄水后的2011-2013年, 采用渔获物调查方法对乌江下游沿河至白马干流江段鱼类进行了调查。两次调查共采集鱼类105种, 其中2006-2008年采集到100种, 2011-2013年采集到62种; 两次调查相比, 广适性鱼类减少10.38%, 湖沼定居型鱼类减少0.98%, 喜流水性鱼类减少9.62%。两个时期的鱼类群落多样性分析显示: 各个调查江段Margalef丰富度指数(R)和Shannon-Wiener多样性指数(H)在2011-2013年均低于2006-2008年。渔获物分析结果表明: 大鳍鳠(Mystus macropterus)、中华倒刺鲃(Spinibarbus sinensis)、瓣结鱼(Tor (Folifer) brevifilis)等鱼类在渔获物中的重量比例从2006-2008年间的大于5%, 下降到2011-2013年间的不足2%, 而(Hemiculter leucisculus)、草鱼(Ctenopharyngodon idellus)、黄颡鱼(Pelteobagrus fulvidraco)等在2011-2013年渔获物中的重量比例有所上升, 成为调查区域的主要渔获对象。丰度生物量比较表明: 2006-2008年鱼类群落结构受到中等程度的干扰, 而2011-2013年受到严重程度的干扰。为保护乌江下游的鱼类生物多样性, 需采取现有栖息地修复、控制过度捕捞等多种资源保护方式。     

Changes in aquatic vegetation and fish communities following 5 years of sustained low water levels in coastal marshes of eastern Georgian Bay,Lake Huron

Aquatic vegetation in the relatively pristine coastal wetlands of eastern Georgian Bay provides critical habitat for a diverse fish community. Declining water levels in Lake Huron over the past decade, however, have altered the wetland plant assemblages in favour of terrestrial (emergent and meadow) taxa and have thus reduced or eliminated this important ecosystem service. In this study, we compared IKONOS satellite images for two regions of eastern Georgian Bay (acquired in 2002 and 2008) to determine significant changes in cover of four distinct wetland vegetation groups [meadow (M), emergent (E), high‐density floating (HD) and low‐density floating (LD)] over the 6 years. While LD decreased significantly (mean ?2995.4 m²), M and HD increased significantly (mean +2020.9 m² and +2312.6 m², respectively) between 2002 and 2008. Small patches of LD had been replaced by larger patches of HD. These results show that sustained low water levels have led to an increasingly homogeneous habitat and an overall net loss of fish habitat. A comparison of the fish communities sampled between 2003 and 2005 with those sampled in 2009 revealed that there was a significant decline in species richness. The remaining fish communities were also more homogeneous. We suggest that the observed changes in the wetland plant community due to prolonged low water levels may have resulted in significant changes in the fish communities of coastal wetlands in eastern Georgian Bay.     

Geographical patterns of parasite infracommunities in the rough scad, Trachurus lathami Nichols, in the Southwestern Atlantic ocean

We assessed temporal variability in parasite infections of rough scad (Trachurus lathami) in 3 samples from Miramar (MI) in 2008, separated by periods of 1 mo, and 2 samples from Villa Gesell (VG), 1 each in 2008 and 2009 (Buenos Aires Province, Argentina), respectively. A sample was also obtained from Cabo Frio (CF) (Brazil) in 2009 to compare differences in parasite communities between fish from this locality and each Argentinean locality. All rough scad were parasitized by at least 1 of 27 parasite species. Similarity-based multivariate analysis revealed significant differences between localities, but temporal homogeneity in each Argentinean locality. Overall, prevalence and abundance of parasite species were most similar between samples from MI and VG, while the greatest differences occurred between samples from MI and CF. A canonical analysis of principal coordinates showed significant differences among samples. Grillotia carvajalregorum was the most important species in determining the position of Argentinean samples, especially those from MI, while Ectenurus virgulus , Raphidascaris sp., and Hysterothylacium sp. were the most important species related to fish from CF. The parasite assemblage of T. lathami showed a notable temporal persistence within the same locality and a high variability at the spatial scale, suggesting the existence of 3 independent stocks of T. lathami in South Atlantic waters.     

Effects of phenanthrene on growth and basic physiological functions of the olive flounder, Paralichthys olivaceus

Flounder were exposed to waterborne phenanthrene (0.5, 1 and 2 μM) for 4 weeks to test effects of waterborne phenanthrene on growth and hematological properties of the olive flounder (Paralichthys olivaceus). The average weight gain (WG) of flounder was significantly decreased in fish exposed to phenanthrene at 2.0 μM for 2 weeks, whereas WGs of fish treated by 1.0 and 2.0 μM phenanthrene for 4 weeks were significantly decreased. However, hepatosomatic index (HSI) and condition factor (CF) of flounder were not significantly affected by phenanthrene exposure. Red blood cell (RBC) count, hemoglobin (Hb) concentration, hematocrit (Ht), the mean corpuscular hemoglobin (MCH) and the mean corpuscular hemoglobin concentration (MCHC) mean levels were decreased with an increase in exposure time of phenanthrene to the fish, but the level of the mean corpuscular volume (MCV) was increased. Plasma bilirubin concentrations were significantly increased following exposure to waterborne phenanthrene (2.0 μM) for 2 and 4 weeks; however, there were no significant changes in plasma total cholesterol in fish of all treated groups compared to control. The phenanthrene-exposed groups (≥1.0 μM) showed significantly higher mean plasma lysozyme activity. Kidney lysozyme activity of fish exposed to phenanthrene (≥1.0 μM) was also significantly higher than that of control fish. The central finding from these data is that olive flounder exposed to waterborne phenanthrene at more than 1.0 μM are likely to experience negative impacts on fish health and basic physiological functions.     

Detection of strobilurin-resistant isolates of Mycosphaerella graminicola in Morocco

Septoria tritici blotch caused by Mycosphaerella graminicola (anamorph: Septoria tritici) is nowadays one of the most frequently occurring diseases on both bread and durum wheat crops. Two hundred and thirty isolates of the fungus were sampled from six distinct wheat-producing regions of Morocco in order to investigate the resistance of M. graminicola to strobilurins in this country, where this fungicide class is increasingly used in wheat-pest management. A subset of 134 isolates was first collected in 2008 from Meknes-Tafilalet, Tadla-Azilal, Gharb and Chaouia. Furthermore, 96 additional isolates were sampled in 2010 from the fourth regions investigated in 2008 plus Fes-Boulmane and Doukkala-Abda. Sensitivity or resistance within the isolates were determined by screening the G143A cytochrome b substitution conferring resistance. We used a mismatch amplification mutation assay allowing the amplification of either G143 (sensitive) or A143 (resistant) allele. All the 2008 isolates were found to be sensitive since they carry the wild-type allele G143. However, 9 (9%) out of the 2010 isolates were found to contain the resistant allele A143 and therefore to be resistant. Four of them were from Gharb and five from Fes-Boulmane. This study highlighted for the first time the occurrence of strobilurin-resistant isolates of M. graminicola in Morocco. Further genetic investigations should determine if the resistant isolates emerged independently in Morocco or traveled by wind-migration from Europe.     

Reactivation of the chloroplast CF1-ATPase beta subunit by trace amounts of the CF1 alpha subunit suggests a chaperonin-like activity for CF1 alpha.

Incubation of tobacco and lettuce thylakoids with 2 M LiCl in the presence of MgATP removes the beta subunit from their CF1-ATPase (CF1 beta) together with varying amounts of the CF1 alpha subunit (CF1 alpha). These 2 M LiCl extracts, as with the one obtained from spinach thylakoids (Avital, S., and Gromet-Elhanan, Z. (1991) J. Biol. Chem. 266, 7067-7072), could form active hybrid ATPases when reconstituted into inactive beta-less Rhodospirillum rubrum chromatophores. Pure CF1 beta fractions that have been isolated from these extracts could not form such active hybrids by themselves, but could do so when supplemented with trace amounts (less than 5%) of CF1 alpha. A mitochondrial F1-ATPase alpha subunit was recently reported to be a heat-shock protein, having two amino acid sequences that show a highly conserved identity with sequences found in molecular chaperones (Luis, A. M., Alconada, A., and Cuezva, J. M. (1990) J. Biol. Chem. 265, 7713-7716). These sequences are also conserved in CF1 alpha isolated from various plants, but not in F1 beta subunits. The above described reactivation of CF1 beta by trace amounts of CF1 alpha could thus be due to a chaperonin-like function of CF1 alpha, which involves the correct, active folding of isolated pure CF1 beta.     

Morphological development of larval cobia Rachycentron canadum and the influence of dietary taurine supplementation

The morphological development of larval cobia Rachycentron canadum from 3 days post hatch (dph) until weaning (27 dph) was examined using S.E.M. Two groups of fish were studied: a control group (CF), reared under standard feeding protocol, and a group in which prey items were enriched with supplemental taurine (4 g l(-1) day(-1) ; TF). TF fish grew faster (P < 0·001), attained greater size (mean ±s.e. 55·1 ± 1·5 v. 33·9 ± 1·0 mm total length) and had better survival (mean ±s.e. 29·3 ± 0·4 v. 7·1 ± 1·2 %) than CF fish. Canonical variance analysis confirmed findings with respect to differences in growth between the treatment groups with separation being explained by two cranial measurements. S.E.M. revealed that 3 dph larvae of R. canadum (in both groups) possess preopercular spines, superficial neuromasts on the head and body, taste buds in the mouth, an olfactory epithelium which takes the form of simple concave depressions, and primordial gill arches. Gill filaments start to form as early as 6 dph and lamellae buds are visible at 8 dph in both groups. In CF fish, the cephalic lateral line system continues its development at 12-14 dph with invagination of both supra- and infraorbital canals. At the same time, a thorn-like or acanthoid crest forms above the eye. At 14 dph, invaginations of the mandibular and preopercular canals are visible and around 22 dph enclosure of all cranial canals nears completion. In CF larvae, however, completely enclosed cranial canals were not observed within the course of the trial, i.e. 27 dph. In TF larvae, grooves of the cephalic lateral line system form 4 days earlier than observed in CF larvae of R. canadum (i.e. at 8 dph), with enclosure commencing at 16 dph, and completed by 27 dph. Along the flanks of 6 dph larvae of either treatment, four to five equally spaced neuromasts delineate the future position of the trunk lateral line. As myomeres are added to the growing larvae, new neuromasts appear such that at 16 dph a neuromast is associated with each myomere. By 27 dph, the trunk lateral line starts to invaginate in CF larvae, while it initiates closure in TF larvae. These findings elucidate important features of the larval development of R. canadum and show that dietary taurine supplementation benefits larval development, growth and survival in this species. Moreover, they suggest a conditional requirement for taurine in larval R. canadum.     

Characterization of Cholesterol-Free Insect Cells Infectible by Baculoviruses: Effects of Cholesterol on VSV Fusion and Infectivity and on Cytotoxicity Induced by Influenza M2 Protein

The patented cell line from the cabbage looperTrichoplusia ni(High Five from Invitrogen) was found to grow readily under cholesterol-free (CF) culture conditions. Cellular cholesterol became undetectable by CF passage 4, while growth rate and overall cell morphology remained unaffected for at least 59 CF passages. The Golgi apparatus in CF cells was significantly smaller than in control cells, and the CF cells also concentrated a ceramide-based fluorescent Golgi marker to a greater extent, but endoplasmic reticulum morphology appeared unaffected. Two proteins were expressed in High Five cells from recombinant baculoviruses under CF and control conditions: the vesicular stomatitis virus (VSV) fusion glycoprotein G and the influenza virus ion channel M2. Both proteins were expressed in comparable amounts in CF and control cells. Both were properly assembled and transported to the plasma membrane in CF cells, indicating the presence of functional Golgi. Wild-type G protein expression resulted in extensive syncytia formation in both CF and control cells, showing that cholesterol is not required for VSV fusion. However, a mutant G protein lacking six transmembrane domain residues was inactive in both CF and control cells. Influenza M2 protein was functional in control cells, as indicated by its amantadine-inhibitable cytotoxicity, but cytotoxicity was absent in CF cells expressing this protein, indicating a cholesterol-dependence for the cytotoxic action of this protein. CF and control cells were both infectible with VSV. However, infected cell centers were modestly decreased (ca. 3.5-fold) in CF cells. CF cells offer a convenient and novel approach to the study of specific cholesterol functions.     

Observational evidence of the sensitivity of some fish species to environmental stressors in Mediterranean rivers

We describe a tolerance classification based on the physicochemical parameters of water and habitat quality indices for native and introduced fish species in northeastern Spain. Although fish are widely used as biological indicators, the tolerance categories currently available for Spanish Mediterranean fish species are uncertain or subjective. We sampled 430 sites covering a wide range of river conditions, allowing us to develop tolerance scores based on a quantitative assessment. We used indirect ordination methods to establish stress gradients between the environmental variables compiled during the monitoring surveys carried out from 2002 to 2008. We then drew up a tolerance classification for the most common species in our dataset using weighted average inference models based on the following gradients: water quality and the state of physical habitat. The results were corroborated by multivariate gradient analysis. The fish scores obtained were applied to an independent dataset and a positive correlation was found between assessment protocols. Our results corroborate the use of fish, including exotic fish species, as biological indicators. Our findings may be used in a regional Index of Biotic Integrity and for the use of fish in bioassessment studies based on scores.     

Effects of stocking density on growth and skin color of juvenile darkbarbel catfish Pelteobagrus vachelli (Richardson)

A 3‐month experiment was conducted to investigate the effects of stocking density on growth performance and skin color of juvenile darkbarbel catfish. Experimental fish (5.0 ± 0.6 g; n = 160) were stocked in triplicate in 2 m² concrete tanks in a greenhouse at the initial density of 50, 150, 400 and 650 fish m^?2, respectively (0.42, 1.25, 3.33 and 5.42 kg m^?3). At the end of the experiment, 60 fish from each tank were sampled to record body weight and total length, and six fish from each tank were sampled to measure skin color by instrumental color analysis. Results showed that stocking density affected growth performance significantly (P < 0.05). Final mean weight (W), final mean total length (L) and specific growth rate (SGR) were significantly higher at 150 fish m^?2 treatment and lower in both the highest and lowest (650 and 50 fish m^?2) density treatments (P < 0.05). The condition factor (CF) was higher in 150 and 50 fish m^?2 and lowest at 650 fish m^?2 treatment; the coefficient of variation of weight (CV) tended to increase with the increase in stocking density, which was lowest in 50 fish m^?2 and highest in 650 fish m^?2. Stocking density also affected the skin color parameters, L* (lightness), a* (redness), b* (yellowness) and h* (hue), significantly (P < 0.05). The values of these parameters tended to decline with the increase in stocking density. Results of the present study suggest that growth performance and skin color responses to stock density exhibit different patterns for darkbarbel catfish juveniles: highest and lowest densities impaired growth rate, and higher density had a darkening effect on skin color.     

Fishing near sea-cage farms along the coast of the Turkish Aegean Sea

This study reports on the yield of commercially important species captured intentionally around and under fish-cage farms using specific types of gear from both sea-cage farmers and artisanal fishermen, and to identify the species composition of these catches. The 2004–2008 research was carried out in 21 fish farms, randomly chosen along the coast of Izmir Province on the Aegean Sea. A total of 91 persons were interviewed, including directors, fishers from the fish farms and artisanal fishermen. The technical characteristics of a special trap used by some fish farmers were diagramed. Total wild fish catch quantities as well the species raised in the sea-cages were recorded. A total of 34 finfish and four invertebrate species were identified from the sea-cage farm fishery. Eight fish species according to the descending quantities raised were bogue ( Boops boops ), grey mullet ( Mugil spp.), blackspot seabream ( Pagellus bogaraveo ), salema ( Sarpa salpa ), common two-banded seabream ( Diplodus vulgaris ), annular seabream ( Diplodus annularis ), striped seabream ( Lithognathus mormyrus ) and gilthead seabream ( Sparus aurata ). Mean quantities of wild fish caught from 2004 to 2008 in a sampled farm were 13 998 ± 210, 34 434 ± 482, 30 116 ± 529, 27 893 ± 429, and 32 366 ± 808 kg, respectively. There were significant differences between fish amounts and years (P   < 0.05).     

Eating catch of the day: the diet of porbeagle shark Lamna nasus (Bonnaterre 1788) based on stomach content analysis,and the interaction with trawl fisheries in the south-western Atlantic (52° S–56° S)

This work examined the diet of the porbeagle shark Lamna nasus in the south-west Atlantic Ocean (SWAO, Argentina, 52° S–56° S) by analysing the stomach content information obtained by scientific observers who sampled specimens captured as by-catch on-board commercial fishing vessels from 2010 to 2020. A total of 148 fishing sites were analysed, in which the estimated catch was composed mainly of hoki Macruronus magellanicus (56.00%) and southern blue whiting Micromesistius australis (33.13%). From 413 porbeagle sharks sampled (292 females and 121 males) ranging from 71 to 241 cm total length (L_T) (mean: 179.76 ± 26.74 cm), 310 (75.06%) contained food in the stomachs. The forage fish were mainly hoki M. magellanicus (23.53%) and southern blue whiting M. australis (19.05%), followed by the Patagonian sprat Sprattus fuegensis (4.48%) and nototheniids (1.4%). Cephalopods and crustaceans accounted for 10% of the diet. The estimated trophic level was 4.35. Generalized linear models revealed that the consumption of hoki M. magellanicus and southern blue whiting M. australis increased with the L_T of the porbeagle shark. Moreover, smaller porbeagle sharks preyed upon both small and large teleost fish, whereas larger porbeagle sharks predated exclusively upon large fish. The diet of porbeagle shark involved interactions with fisheries as it fed upon the fish species that constituted the main catch in the analysed fishing sites, as well as the main catches of the austral trawl fisheries. The ecological role of porbeagle shark observed in the SWAO exposed implications for fisheries management from a multispecies perspective.     

Parasite diversity as an indicator of environmental change? An example from tropical grouper (Epinephelus fuscoguttatus) mariculture in Indonesia

Fish parasites are used to monitor long-term change in finfish grouper mariculture in Indonesia. A total of 210 Epinephelus fuscoguttatus were sampled in six consecutive years between 2003/04 and 2008/09 and examined for parasites. The fish were obtained from floating net cages of a commercially run mariculture facility that opened in 2001. The fauna was species rich, consisting of ten ecto- and 18 endoparasite species. The ectoparasite diversity and composition was relatively stable, with the monogeneans Pseudorhabdosynochus spp. (83-100% prevalence, Berger-Parker Index of 0·82-0·97) being the predominant taxon. Tetraphyllidean larvae Scolex pleuronectis and the nematodes Terranova sp. and Raphidascaris sp. 1 were highly abundant in 2003/04-2005/06 (max. prevalence S. pleuronectis 40%, Terranova sp. 57%, Raphidascaris sp. 1 100%), and drastically reduced until 2008/09. These parasites together with the prevalence of Trichodina spp., ecto-/endoparasite ratio and endoparasite diversity illustrate a significant change in holding conditions over the years. This can be either referred to a definite change in management methods such as feed use and fish treatment, or a possible transition of a relatively undisturbed marine environment into a more affected habitat. By visualizing all parameters within a single diagram, we demonstrate that fish parasites are useful bioindicators to monitor long-term change in Indonesian grouper mariculture. This also indicates that groupers can be used to monitor environmental change in the wild. Further taxonomic and systematic efforts in less sampled regions significantly contributes to this new application, supporting fish culture and environmental impact monitoring also in other tropical marine habitats.     

Anemia, iron deficiency, and stress fractures in female combatants during 16 months

Yanovich, R, Merkel, D, Israeli, E, Evans, RK, Erlich, T, and Moran, DS. Anemia, iron deficiency, and stress fractures in female combatants during 16 months. J Strength Cond Res 25(12): 3412-3421, 2011-The purpose of this study is to evaluate the hematological profile of military recruits in different settings and training programs and to investigate the link between anemia and iron deficiency with stress fracture (SF) occurrence. We surveyed 3 groups of recruits for 16 months: 221 women (F) and 78 men (M) from 3 different platoons of a gender-integrated combat battalion and a control group (CF) of 121 female soldiers from a noncombat unit. Data were fully collected upon induction and at 4 and 16 months from 48F, 21M, and 31CF. Blood tests, anthropometry, physical aerobic fitness, and SF occurrence were evaluated. On induction day, 18.0 and 19.0% of F and CF were found to be anemic, and 61.4 and 50.9%, respectively, were found to have iron deficiency, whereas 7.7% of M were found to be anemic and 10.2% iron deficient. During the 4 months of army basic training (ABT), anemia and iron deficiency prevalence did not change significantly in any group. After 16-months, anemia prevalence decreased by 8% among F and CF and abated in M. Iron deficiency was prevalent in 50.0, 59.4, and 18.8% of F, CF, and M, respectively. Stress fractures were diagnosed in 14 F during ABT, and they had a significantly higher prevalence (p < 0.05) of anemia and iron deficiency anemia compared to F without SFs. The observed link between anemia and iron deficiency on recruitment day and SFs suggests the importance of screening female combat recruits for these deficiencies. To minimize the health impact of army service on female soldiers, preventative measures related to anemia and iron deficiency should be administered. Further research is needed for evaluating the influence of low iron in kosher meat as a possible explanation for the high prevalence of iron deficiency among young Israeli recruits.     

Induced resistance activated by a culture filtrate derived from an avirulent pathogen as a mechanism of biological control of anthracnose in strawberry

In a previous report, it was described that strawberry plants pre-treated with an avirulent isolate of Colletotrichum fragariae (M23) acquired resistance to a virulent isolate of Colletotrichum acutatum (M11) causing anthracnose. In this report we present evidence that the eliciting activity can be found not only in conidial extracts but in culture supernatants of the avirulent pathogen as well. Plants of the cv. Pájaro treated with the culture filtrate (CF) derived from M23, 3 days prior to the inoculation with M11 showed significantly reduced disease severity as compared to control plants and the disease was completely suppressed when plants were pre-treated 7 days before the challenge inoculation with M11. The same effect was achieved when a single leaf was sprayed with CF, suggesting that the resistance acquired is systemic. Control treatments showed that none of the active extracts inhibited the growth of the virulent pathogen, indicating that the protection effect was due to the induction of a defense response. The latter was confirmed by the accumulation of reactive oxygen species (e.g. hydrogen peroxide, superoxide anion) and the deposition of lignin and callose, usually associated to plant defense, after the CF treatment. Experiments carried out with other strawberry cultivars treated with CF showed that also protected them against different virulent isolates, suggesting that the response observed is cultivar-nonspecific. These outcomes indicate that the protection against anthracnose in strawberry involves a phenomenon of induced resistance (IR) by action of defense-eliciting molecules produced by M23.     

Infection dynamics of Cichlidogyrus tilapiae and C. sclerosus (Monogenea, Ancyrocephalinae) in Nile tilapia (Oreochromis niloticus L.) from Uganda

The infection dynamics of the gill monogeneans Cichlidogyrus tilapiae and C. sclerosus on Oreochromis niloticus with respect to habitat type (reservoir, stream, ponds and cages), host sex, size and seasons was determined between January and November 2008. During the study period, 45.2% of the 650 fish examined were infected with Cichlidogyrus spp. The infected hosts harboured an average of 8.6 ± 3.4 parasites/fish. Across habitat types, the proportion of infected fish was not statistically different. In contrast, the number of parasites recorded on infected fish from different habitat types differed significantly. The highest parasite number was recorded in reservoir-dwelling fish and lowest in stream-dwelling hosts. Concerning sex, more female O. niloticus were infected and harboured a high number of parasites than male and sexually undifferentiated fish. A weak negative relationship was found between rainfall and monthly parasite infections. However, a higher number of parasites and proportion of infected hosts were found during dry than in wet seasons, except in ponds. Results of this study show that differential exposure due to changes in fish behaviour associated with habitat modification and sex may account for the infection difference across the sampled sites. Meanwhile, rainfall and the associated hydrological events are important factors regulating monogenean infections in tropical aquatic environments. The continuous presence of Cichlidogyrus spp. in fish provides evidence of possible parasite outbreaks, indicating the application of biosecurity measures as crucial for the success of intensive fish farming.     

The effect of largemouth bass Micropterus salmoides on aquatic macro-invertebrate communities in the Wit River,Eastern Cape,South Africa

Fish predation is one of the driving forces of freshwater invertebrate community structures, with alien predators having a pronounced effect. A quantitative assessment of aquatic invertebrates in the Wit River, Sundays River catchment, Eastern Cape, South Africa, was undertaken to assess the impact of the alien fish Micropterus salmoides on their relative abundance and community structure. Communities in the stones-in-current and marginal vegetation biotopes were sampled in the presence and absence of M. salmoides in late summer (February–April) 2008. Results suggest that the presence of M. salmoides does have an impact on indigenous macroinvertebrate fauna and communities. Community structure in the stones-in-current biotopes did not differ significantly between sections of the river with or without fish. However, there was a significant difference in community structure in marginal vegetation between sections of river. In sections with M. salmoides several large or conspicuous taxa (Odonata, Hemiptera and Coleoptera) were significantly reduced (p < 0.05) or even absent, while cryptic/inconspicuous taxa (Trichoptera, Leptoceridae and Mollusca, Physidae) were significantly more abundant (p < 0.05).     

Coral-reef sounds enable nocturnal navigation by some reef-fish larvae in some places and at some times

At Lizard Island, Great Barrier Reef, catches of fish larvae by light traps that broadcast nocturnal reef sounds (noisy traps) were compared with catches by quiet traps over two 2·5 week new-moon periods in November (XI) 2000 and January (I) 2001. Three areas were sampled: near-reef (NR, 500 m from the shore) in I, middle (M, 650 m) in I and XI and offshore (O, >1000 m) in XI. The most abundant taxa captured were Apogonidae, Blenniidae, Chaetodontidae, Lethrinidae, Mullidae and Pomacentridae. Significant differences in catch were found between areas, and a position effect was found at the O and M areas. At the NR and M areas, no taxa had significantly greater catches in quiet traps, but larvae of five taxa had significantly greater catches in noisy traps. These were (areas and times of greater catches): Apogonidae (NR; M XI), Mullidae (M I & XI), Pomacentridae (NR; M I & XI), Serranidae (M I) and Sphyraenidae (NR). At the offshore area, five taxa (Apogonidae, Blenniidae, Chaetodontidae, Mullidae and Pomacentridae) had significantly greater catches in quiet traps and only Lethrinidae had significantly greater catches in noisy traps. Thus some taxa (particularly apogonids and pomacentrids which had catches up to 155% greater in noisy traps, but also lethrinids and mullids, and perhaps others), were attracted to reef sounds at night, but this apparently varied with location and time. The sound-enhanced catches imply a radius of attraction of the sound 1·02–1·6 times that of the light. More than 65 m from the speaker,the broadcast sound levels at frequencies typical of fish hearing were equivalent to background levels, providing a maximum radius of sound attraction in this experiment.     

Modulation of the antioxidant activity of HO* scavengers by albumin binding: a 19F-NMR study

The interaction between different HO(z.rad;) radical scavengers in a three-component antioxidant system has been investigated by means of 19F-NMR spectroscopy. This system is composed of bovine serum albumin (BSA), trolox, and N-(4-hydroxyphenyl)-trifluoroacetamide (CF(3)PAF). The antioxidant capacity of BSA and trolox has been assessed by measuring the amount of trifluoroacetamide (TFAM) arising from the radical mediated decomposition of CF(3)PAF. When assayed separately, both trolox and BSA behaved as antioxidants, as they were effective to protect CF(3)PAF from HO* radical-mediated decomposition. By contrast, trolox enhanced the production of TFAM in the presence of BSA, thus behaving as a pro-oxidant. Urate, carnosine, glucose, and propylgallate showed antioxidant properties both with or without BSA. CF(3)PAF and trolox were found to bind to BSA with association constants in the order of 5 x 10(3)M(-1) and to compete for the same binding sites. These results have been discussed in terms of BSA-catalysed cross-reactions between trolox-derived secondary radicals and CF(3)PAF.     

Cross-reactive antibodies to mycoplasmas found in human sera by the enzyme-linked immunosorbent assay (ELISA)

Antibodies against Mycoplasma pneumoniae in patients' sera with M. pneumoniae infection were measured by the complement fixation (CF) test and enzyme-linked immunosorbent assay (ELISA). Many patients' sera cross-reacted with heterologous mycoplasmal ELISA antigens such as M. hominis, M. hyorhinis, M. orale, M. pulmonis and M. salivarium. The sera with high CF (CF greater than or equal to 40) titers gave significantly higher ELISA values to M. hyorhinis (P less than 0.001) and M. pulmonis (P less than 0.001), which are not parasitic for humans, than those with low CF (CF less than 20) titer. Human normal immunoglobulin G (human normal IgG) containing 98% or more IgG, prepared from pooled plasma of at least 500 normal human donors, showed ELISA reactions with all mycoplasmal strains used. The nonspecific adsorption of human normal IgG on the surface of plate wells and on medium components which might contaminate mycoplasmal ELISA antigens could be disregarded. These results suggest that cross-reactive antibodies to mycoplasmas exist in human sera, and they affect the results of ELISA for serodiagnosis of M. pneumoniae infection.