Salinity Tolerance in Some Selected Aquatic Oligochaetes

Salt tolerance of the freshwater tubificid Limnodrilus hoffmeisteri varied from an LD 50 of 10 ppt to 10.5 ppt for mature and immature worms without sediment, 9.4 to 10.5 in sand, and 14.3 for immatures acclimated to 5 ppt. Ilyodrilus templetoni was similarly intolerant to higher salinities. The estuarine Tubificoides gabriellae tolerated salt water, but was susceptible to freshwater, with LD 50's of 2 and 3.5 when acclimated to 5 and 10 ppt sea water. It survived immersion in freshwater for 3 hours. The estuarine naidids Paranais litoralis and frici experienced mortalities at both high and low salinities but showed a wide tolerance range. The coastal tubificid Monopylephorus irroratus showed almost complete tolerance to the salinity range employed. The findings reflected field distributions especially when interstitial salinities were measured, but worms did not occupy the full range of habitats possible in terms of salinity alone.     

Ontogenetic Changes of Photosynthetic and Dark Respiration Rates in Relation to Nitrogen Content in Individual Leaves of Field Crops

Ontogenetic changes of rates of photon-saturated photosynthesis (P _sat) and dark respiration (R _D) of individual leaves were examined in relation to nitrogen content (Nc) in rice, winter wheat, maize, soybean, field bean, tomato, potato, and beet. P _sat was positively correlated with Nc as follows: P _sat = CfNc + P _sat0, where Cf and P _sat0 are coefficients. The value of Cf was high in maize, medium in rice and soybean, and low in field bean, potato, tomato, and beet, of which difference was not explained by ribulose-1,5-bisphoshate carboxylase/oxygenase (RuBPCO) content. R _D was explained by P _sat and/or Nc, however, two models must be applied according to plant species. R _D related linearly with P _sat and Nc in maize, field bean, and potato as follows: R _D = a P _sat + b, or R _D = aNc + b, where a, a, b and b are coefficients. In other species, the R _D/P _sat ratio increased exponentially with the decrease of Nc as follows: R _D/P _sat = a exp(b Nc), where a and b are coefficients. Therefore, R _D in these crops was expressed as follows: In(R _D) = ln(a P _sat) + b Nc, indicating that R _D in these crops was regulated by both P _sat and Nc.     

Oligochaete respiration as a measure of sediment toxicity in Puget Sound,Washington

Respiration rate measurements were conducted with the marine oligochaete Monopylephorus cuticulatus Baker and Brinkhurst to determine the sublethal toxicity of sediments collected from Puget Sound, Washington. Worms were exposed to elutriates prepared from centrifuged sediment slurries. Standard respiration rates were measured at high dissolved oxygen levels for each sample tested and were compared with control and other test results. A total of 97 sediment samples were tested; 40 samples demonstrated significant respiration effects (elevation or depression). Comparison with results of other tests conducted at the same stations or geographic locations (genotoxicity to fish cells, lethality to sensitive species, reproductive impairment tests) indicated very good agreement on broad scale toxicity patterns at different geographical areas, and that respiration measurements effectively determined sublethal toxicity of sediments. This study represents the first application of respiration measurements as a sublethal toxicity test for field-collected sediments.     

Properties of Gracilaria agars

Data are presented concerning an investigation into the diversity, abundance, production and respiration of the oligochaete fauna in the eutrophic, polymictic Lake Zbechy and in a melioration canal in the Wielkopolska Region, an area of intensive agriculture. It was found that in the canal the average biomass of oligochaetes was about four times higher than in the lake. Oligochaetes expend 1.1–4 times more energy in respiration than in tissue production. Species diversity and species number are positively correlated, while the correlation between diversity and abundance is negative.     

Comparative Physiology of Respiration in Aquatic Fungi

A comparative study of terminal respiration was undertaken in five genera of aquatic fungi in the Leptomitales. The cytochrome system in this group of fungi contained cytochrome a-a₃ (605 nm), cytochrome c (551 nm), cytochrome b (557 nm), and cytochomo b (564 nm). A representative of each of three aerobic genera, Leptomitus, Apodachlya, and Sapromyces, had a total cytochrome content of about 2×10^?10 mol/mg dry weight. An endogenous respiration rate of 21 μl O₂ uptake/ (h × mg dry weight) at 21.7°C was found in Leptomitus and Apodmhlya and 14 in Sapromyces. The strain belonging to the fermenlative genus Mindeniella had approximately one-third of the total cytochrome content and one-third of the endogenous respiration rate observed in Leptomitus and Apodachlya. Mindeniella and Sapromyces contained less total cytochrome when grown under reduced oxygen tension than when grown in air. Only about one-half of the b-type cytochrome was redueible by endogenous substrates. Both cytochrome a₃ and an unidentified pigment bound CO. The endogenous respiration of Leptomitus, Apodachlyo, and Sapromyces was strongly Inhibited by sodium cyanide, sodium azide, antimycin A, and sodium fluoroacetate.     

Cyanide-Resistant Respiration in Relation to Fruit Respiratory Climacteric

Changes in respiratory rate and the effects of respiratory inhibitorson respiration were determined in apple (Malus sylvestris cv. Delicious) and red pepper (Capsicum fructescens) fruits dusting different stages of development and ripening.The results showed that there was an abrupt rise in respiration daring ripening inapple fruit, but the respiration of the red pepper declined continuously throughout theripening period. Thus the apple is climacteric and the red pepper is non-climacteric fruit. The respiration of apple fruit was sensitive to KCN (1 mM) during the period ofdevelopment but changed to CLAM-sensitive and CN-resistant during preclimactericand climacteric phases, indicating that a diversion of respiratory pathways from the cy-tochrome path to the alternative path has occurred. The respiration of the red pepperfruit was CN-sensitive thoughout the whole period of fruit ripening, suggesting thatthe operation of the CN-resistant path was insignificant. Slices from climacteric apple fruits developed induced .respiration after aging, bothKCN and CLAM (1 mM) inhibited the induced respiratic considerably. However, slices from red pepper fruits showed no evidence of induced respiration after aging. Slices from climacteric apple fruits infiltrated with 3 mM CLAM before aging, reducedthe peak of the induced respiration by about 30%, indicating that the development ofinduced respiration was suppressed by the presence of CLAM. The above results indicated that the: climacteric fruits were characterized by diversion of traffic from the cytochrome path to the alternative path during ripening andby the development of induced respiration after slicing and aging. While in nonclimacteric fruits no .diversion of electron transport path was observed during ripening andno induced respiration occurred after aging. Although both the eytochrome and alternative pathways were present in the tissue of red pepper fruits, the alternative pathwas not operating except when the cytochrome path was blocked or was saturated by electron flow.     

A Microflow Respirometer for Measuring the Oxygen Consumption of Small Aquatic Organisms

A microrespiration device is decribed which uses a Clark electrode to measure the oxygen consumption or production of small and microscopic aquatic organisms in an open flow system. The construction and working principles of the device, which can measure oxygen consumptions as low as 0.5 nl · h⁻¹, are described. The design of the apparatus permits parallel measurements under identical conditions with a single electrode. The device can be matched to various sizes of animal and oxygen consumption rates by means of specimen chambers of different volumes (6 μl, 35 μl, 140 μl) and a variable water flow rate. The microflow respiration device has been used successfully to measure the respiration of zooplankton and meiobenthos organisms as well as protozoans and has also been used successfully on board a research vessel.     

山东水生药用植物调查研究

本调查共采集山东省水生植物标本800余份,经鉴定,其中水生药用植物共有65科82属128种,按功效将其分为12类。文中评析了山东省水生药用植物资源特点,并提出相应的开发策略。     

Some ecological aspects of aquatic oligochaetes in the Lower Pearl River (People's Republic of China)

Densities of the 8 most important species or genera of the 15 taxa found at a series of stations along the Guangzhou Reach of the Pearl River are given. Shannon-Weaver diversity index values were low throughout the area studied. No clear correlations were found between oligochaetes and NH₃-N or a combination of 6 chemical factors (COD, NH₃-N, NO₃-N, Cr, Pb, Hg). However, when the main groups of the benthos, including the oligochaetes, were taken together, and a BPI (Biological Pollution Index) approach used, a correlation between the macroinvertebrate community and the combined chemical factors was noted.     

Respiration of turions and winter apices in aquatic carnivorous plants

Basic respiration characteristics were measured in turions of six aquatic plant species differing greatly in their ecological and overwintering characteristics both before and after overwintering, i.e., in dormant and non-dormant state: non-carnivorous Hydrocharis morsus-ranae and Caldesia parnassifolia and carnivorous Aldrovanda vesiculosa, Utricularia australis, U. ochroleuca, and U. bremii, and in non-dormant winter apices of three Australian (sub)tropical populations of Aldrovanda and of two temperate North American Utricularia species, U. purpurea and U. radiata. Respiration rate of autumnal (dormant) turions at 20°C ranged from 0.36 to 1.3 μmol O₂ kg⁻¹ (FM) s⁻¹ and, except for U. bremii, increased by 11–114% after overwintering. However, this increase was statistically significant only in two species. Respiration Q₁₀ in dormant turions ranged within 1.8–2.6 and within 2.3–3.4 in spring (non-dormant) turions. Turions of aquatic plants behave as typical storage, overwintering organs with low respiration rates. No relationship was found between respiration rate of turions and overwintering strategy. In spite of their low respiration rates, turions can usually survive only from one season to another, due to their limited reserves of respiratory substrates for long periods. Contrary to true turions, respiration rates in non-dormant winter apices both in Australian Aldrovanda populations and temperate U. radiata and U. purpurea, in sprouting turions, and growing shoot apices of Aldrovanda were high and ranged from 2.1 to 3.1 μmol kg⁻¹ (FM) s⁻¹, which is comparable to that in aquatic plant leaves or shoots.     

部分水产养殖动物性别控制基因的研究进展

动物的性别是受遗传或环境等因素控制的。自从在哺乳动物中发现了性别决定基因SRY后,还发现了许多其他与性别控制和性腺发育相关的基因。由于海水养殖动物的性别控制技术在遗传育种和生产中十分重要,因此利用现代分子生物技术研究性别控制的基因成为热点。本文综述了鱼类、锯缘青蟹、海龟和海胆等水产养殖动物性别控制基因的研究进展。     

Oligochaetes in the southern basin of the Venetian Lagoon: community composition, species abundance and biomass

The oligochaete community of the Chioggia Lagoon (southern basin of the Venetian Lagoon) has been studied from May 1992 to May 1994, at ten fixed sampling stations, distributed across the lagoon. Numerous data regarding composition, abundance, biomass and the breeding periods of the species in the community have been obtained. Nine tubificid species, recently reported for the Mediterranean and Ponto-Caspian areas have been collected. Among them only three were abundant everywhere, except in the innermost part of the lagoon, and throughout the year: Tubificoides vestibulatus, T. swirencowi and Limnodriloides maslinicensis. Only one enchytraeid genus, Grania, has been found restricted to an area near the connection with the sea. The values for the Shannon Diversity Index for the community never exceeded 0.8 and were mainly between 0.4 and 0.7. The most interesting result was the decrease of abundance and biomass, proceeding from the sea mouth (about 6000 ind m^–2) towards the innermost part of the lagoon (less than 100 ind. m^–2). Correlations are suggested with the different grain size of the sediment.     

渗透胁迫对小麦幼苗根系呼吸的影响

用PEG—6000调节培养液的渗透势,研究了渗透胁迫对小麦幼苗根系呼吸作用的影响。在-0.5 MPa的溶液中根总呼吸强度显著降低,不同苗龄根的反应差异明显;随胁迫加强呼吸强度随之降低;根系ATP含量减少。在胁迫初期呼吸废物对呼吸强度的降低无补偿作用,而在后期(72 h后)则可提高呼吸强度。 中度水分胁迫下,HMP支路活性上升,EMP-TCAO途径活性降低;抗氰呼吸活性增大,而对氰敏感的系统活性减低;细胞色素氧化酶活性显著低于对照。     

Sublethal responses of the German cockroach to vapors of commercial pesticide formulations

The effects of vapors of four commercial propoxur formulations and their solvent systems (blanks) on dispersal of German cockroaches, Blattella germanica (L.), of a laboratory susceptible and two propoxur-resistant field strains were studied. Little or no dispersal occurred in experiments with water-based formulations (emulsifiable concentrate and wettable powder). Rapid dispersal occurred in experiments with aerosol and propoxur-in-oil formulations and their blanks. The order from most rapid to slowest dispersal was as follows: propoxur-in-oil, aerosol, aerosol blank and oil blank. Each strain differed from the others in response to at least one of the test materials.

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Résumé L'étude a porté sur les effets des vapeurs de quatre formules commerciales de propoxure et de leurs solvants sur la dispersion d'une souche sensible de laboratoire et de deux souches résistantes de la nature de B. germanica L.. Avec des solutions aqueuses, concentré émulsifiable ou poudre mouillable, la dispersion est faible ou nulle. Une dispersion rapide est obtenue avec des aérosols ou des formules de propoxure en solution dans l'huile ou avec ces solvants seuls. Le classement, du dispersant le plus rapide au plus lent, est le suivant: Propoxure dans l'huile, aérosol, solvant d'aérosol, solvant de solution huileuse. Chaque souche diffère des autres pour au moins une réaction à l'une des substances testées.

     

Aquatic Oligochaeta in Italy, with special reference to Naididae

We present a list of Italian freshwater and marine Oligochaeta in the families Lumbriculidae, Haplotaxidae, Tubificidae, Naididae, Propappidae, Criodrilidae, and Lumbricidae, representing 57 genera and 130 species. Published data reflect the incomplete knowledge of the Italian oligochaete fauna, restricted to certain geographical areas. Subterranean aquatic and marine fauna are of particular interest as these have been studied the least. We provide a comprehensive review of the Naididae including, for the first time, southern Italy and the islands of Sicily and Sardinia. The distribution of species is discussed and taxonomic problems arising from the morphological variability of Italian material are examined.     

The position of the Haplotaxidae in the evolution of oligochaete annelids

The Haplotaxidae have all the characteristics to support the hypothesis that they are the living descendents of the stem forms from which all of the Oligochaeta Clitellata (Orders Lumbriculida, Haplotaxida, Lumbricida, Tubificida) can be derived. The Aphanoneura are distinct from the Clitellata and are raised to a separate Class. There is no evidence to support the view that the elaborate setae of many Tubificida are derived from a polychaete ancestry; both are held to be independent modifications to aquatic life derived from a simple burrowing protoannelid with lumbricine setae.     

Diversity and zoogeography of marine Tubificidae (Annelida,Oligochaeta) with notes on variation in widespread species

The specific and generic diversities of the marine Tubificidae (Annelida, Oligochaeta) of the NE Pacific are compared to those of the NE and NW Atlantic as well as to those of Heron Island, Australia. Diversity in the NE Pacific is relatively high when compared to that of the NE Atlantic. The Tubificidae of the NW Atlantic (limited to the eastern coast of the USA) show two distinct zoogeographic regions: Florida to Cape Hatteras; Cape Hatteras to Massachusetts. Diversity, both in terms of the number of species and number of genera, is approximately the same in these two regions, and is similar to that of both the NE Pacific and Heron Island. Evidence suggests that the widespread marine species, in particular Tubificoides pseudogaster, have a range of morphotypes across their distributions. The apparent wide distributions of these species may be due to a taxonomy unable to resolve the differences between the morphotypes. The tubificid oligochaete fauna of the NE Atlantic appears impoverished compared to the other regions examined. The NE Pacific, NW Atlantic, and Heron Island regions are not dominated by one group of species while the NE Atlantic fauna is dominated by Tubificoides benedeni and Clitellio arenarius.     

A comparison of phenetic and phylogenetic methods applied to the systematics of Oligochaeta

A comparative study of naidid subfamilies shows that a combination of ordination, Jaccard/Average Linkage cluster analysis and Wagner parsimony provides a useful basis for a rational phylogeny but that this does not differ markedly from the original proposed by Sperber nearly four decades ago. Hennig rules, modified by Wiley, permit a preliminary phylogeny and classification of the Annelida to be made by hand. An error in earlier versions suggested that the Dorydrilidae lacked prostate glands, and this is corrected.     

Lethal and sublethal tolerances of aquatic oligochaetes with reference to their use as a biotic index of pollution

A series of recent studies have been completed by the authors involving: 1) determining the lethal tolerances of 12 oligochaete species classified (from ecological studies) as tolerant, moderately tolerant and intolerant to selected chemical toxicants and environmental factors under defined bioassay conditions with and without sediment; 2) determining lethal tolerances of candidate species to toxicants in combination with a range of abiotic factors; 3) measuring respiratory stress imposed by exposure to individual and combined sublethal concentrations of toxicants and environmental factors; and, 4) determining differences in lethal tolerance and respiratory stress between individual and mixed species. Surprisingly few previous studies have been done in this area considering the importance of oligochaetes as field pollution indicators. The results of the above major studies coupled with histopathological work are reviewed. Data from these studies substantiate the present use of oligochaete species assemblages as indicators of organic pollution and suggest their use in the laboratory for toxicant screening tests. The range of responses of different oligochaete species to individual and combined stress is complex, particularly in mixed species, which provides useful indications of specific stress factors. The application of these experimental laboratory studies to field situations is described.     

A taxonomic and faunistic survey of the marine Tubificidae and Enchytraeidae (Oligochaeta) of Italy. Introduction and preliminary results

On the basis of material collected along the Ligurian, Tyrrhenian, Ionic and Adriatic coasts of Italy, a tentative list of 26 species (18 tubificids, 8 enchytraeids) of marine Oligochaeta is presented. Most of the species are new to science, and it can therefore be concluded that there is a very high diversity of oligochaetes in the Mediterranean Sea.