База резюме и ссылок по экологии бентоса
жүктеу/скачать 1.21 Mb.
|
- Бұл бет үшін навигация:
- Речные раки. Местообитания в водотоках.
- Речной рак: роль в экосистеме, Н.Зеландия
- Креветки: влияние на водоросли в разных масштабах.
- Креветки: влияние засухи в реке, Пуэрто-Рико
- Бокоплавы: влияние минерализации.
- Бокоплавы: биология Synurella
- Gammarus fossarum, питание
- Ракообразные: экология метаморфоза Diaptomus
- Водотоки: низшие ракообразные.
РакообразныеGammarus, ручей в Англии, дрифт. A CONTINUOUS STUDY OF THE TOTAL DRIFT OF FRESHWATER SHRIMPS, GAMMARUS PULEX, IN A SMALL STONY STREAM IN THE ENGLISH LAKE DISTRICT Авторы J.M. Elliott Журнал Freshwater Biology Год выпуска 2001 Том 46 Номер 4 Страницы 75-86 Статус 1. The objective was to determine the major factors affecting the downstream dispersal (drift) of freshwater shrimps, Gammarus pulex. Sample replication and frequency are major problems in the quantification of drift. For the first time, these problems were avoided by sampling the whole stream continuously so that all the shrimps drifting downstream at the sampling point were caught in a net emptied at dusk and dawn in 1966, and every 3 days in 1967. 2. There was no consistent seasonal pattern in drift rates, but a high proportion of annual drift was taken in only a few samples. There was a nocturnal diel pattern of drift with peaks soon after dusk and just before dawn. A power function described the significant (P < 0.001) relationship between drift and flow, and was used to neutralise the dominant effects of flow by standardising total drift over 24 h, nocturnal drift and diurnal drift (drift per 50 m3). These were all significantly (P < 0.001) related to benthos density, but not to date, temperature, or length of the night or day. 3. The relationship between drift values and the independent variables, flow and benthos density, was well described (P < 0.001) by a multiple-regression model. Adding temperature, date, and/or the length of the night or day did not improve model fit. Variations in flow and benthos density explained 94% of the variation in total drift over 24 h, 97% of the variation in nocturnal drift, but only 44% of the variation in diurnal drift. A power function described (P < 0.001) the relationship between total drift and the volume of water sampled over 3-day periods in 1967. Flow explained 95% of this drift variation; it was unnecessary to add another variable such as benthos density. 4. The significance of this study is that it avoided the problems associated with the quantification of drift samples. Therefore, the conclusions are more robust than those of many previous studies. A high proportion of the annual drift losses would have been undetected by intermittent sampling. Temperature, season, night or day length had no significant effect on drift densities, and the relationship between drift and benthos densities was proportional, not density dependent. The nocturnal increase in drift could not be interpreted as an antipredator behaviour. The dominance of flow and benthos density was apparent but the quantitative relationships posed further questions, especially those related to drift distances at different velocities. 1. Цель состояла в том, чтобы определить главные факторы, затрагивающие вниз по течению рассеивание (дрейф) пресноводных креветок, Gammarus pulex. Типовой ответ и частота - главные проблемы в определении количества дрейфа. Впервые, этих проблем избегали, пробуя целый поток непрерывно так, чтобы все креветки, дрейфующие вниз по течению в пункте осуществления выборки были пойманы в сети, освобожденной в сумраке и рассвете в 1966, и каждые 3 дня в 1967. 2. Не было никакого последовательного сезонного образца в нормах дрейфа, но высокая пропорция ежегодного дрейфа была принята только несколько образцов. Был ночной образец diel дрейфа с пиками вскоре после сумрака и как раз перед рассветом. Функция власти описала существенное (P <0.001) отношения между дрейфом и потоком, и использовалась, чтобы нейтрализовать доминирующие эффекты потока, стандартизируя полный дрейф более чем 24 h, ночной дрейф и дневной дрейф (дрейф в 50 м. 3). Они были всеми значительно (P <0.001) связанный с плотностью бентоса, но не до настоящего времени, температурой, или длиной ночи или дня. 3. Отношения между ценностями дрейфа и независимыми переменными, потоком и плотностью бентоса, были хорошо описаны (P <0.001) моделью многократного регресса. Добавляя температуру, дата, и/или длина ночи или дня не улучшали пригодную модель. Изменения в потоке и плотности бентоса объяснили 94 % изменения в полном дрейфе более чем 24 h, 97 % изменения в ночном дрейфе, но только 44 % изменения в дневном дрейфе. Описанная функция власти (P <0.001) отношения между полным дрейфом и объемом воды, выбранной за 3-дневные периоды в 1967. Поток объяснил 95 % этого изменения дрейфа; было ненужно добавить другую переменную типа плотности бентоса. Речные раки. Местообитания в водотоках.Freshwater Biology Volume 43 Issue 1 Page 75 - January 2000 Habitat use by crayfish in stream pools: influence of predators, depth and body size Goran Englund* and James J. Krupa SUMMARY 1 Crayfish in headwater streams are subjected to predation from two sources: (a) fish; and (b) terrestrial predators including wading birds and mammals. Field observations of the mortality of tethered crayfish of two size classes were used to examined how predation risks imposed by the two types of predators varied with water depth and crayfish size. We also examined the depth distribution of large and small crayfish in stream pools with and without predatory fish. 2 Predatory fish, mostly green sunfish, Lepomis cyctuellus, and creek chub, Semotilus atromaculatus, rapidly consumed tethered small crayfish (body length = 25-30 mm) in deep areas (0.4-0.7 m), but not in shallow areas (0.05- 0.15 m) of stream pools. Tethered large crayfish (body length = 50-75 mm) suffered little mortality from fish at either depth. Terrestrial predators such as racoons, Procyou lotor, and herons, Butorides and Ardea, caused little crayfish mortality in deep areas, but rapidly consumed both small and large crayfish exposed in shallow areas. 3 A comparison of habitat use by crayfish in pools with and without fish suggests that small, but not large, crayfish shift their distributions to shallow water in the presence of fish. In pools without fish, the distribution of small crayfish was independent of depth, whereas large crayfish occupied deep water.
Речные раки.Freshwater Biology Volume 46 Issue 5 Page 641-652 - May 2001 New Zealand stream crayfish: functional omnivores but trophic predators? Stephanie M. Parkyn, Kevin J. Collier & Brendan J. Hicks 1. The feeding ecology of the crayfish Paranephrops planifrons in streams draining catchments in native forest and pastoral land was investigated using analyses of both stomach contents and stable isotopes of carbon and nitrogen. We aimed to (1) identify the energy sources of crayfish, (2) determine whether these were affected by ontogeny or land use change, and (3) assess the functional and trophic roles of crayfish in New Zealand hill-country streams. 2. In native forest streams, crayfish stomach contents were dominated volumetrically by leaf detritus (>60), but in pasture streams aquatic invertebrates constituted more than 40 of stomach volumes and leaf detritus <30. Stable isotope analyses revealed that crayfish from both native forest and pasture streams incorporated energy from aquatic invertebrates into their body tissue but did not appear to utilize detritus for growth. Therefore, deforestation had little impact on crayfish energy sources. 3. In native forest streams, adult crayfish (=" border=0 src="/na102/home/ACS/journals/entities/2265.png"20mm orbit-carapace length (OCL)) consumed greater amounts of leaf detritus than juvenile crayfish, but a corresponding change in stable isotope signatures was not detected. Ontogenetic shifts in diet were not consistent between land use suggesting that change in local habitat and food resources, as a result of land use change, affect crayfish food choice more than factors related solely to age or size. 4. Crayfish appear to occupy the trophic position of a predator, but by functioning as omnivores, they have dual roles as both predators and processors of organic matter. The use of gut content analysis in conjunction with stable isotope analyses revealed that the functional and trophic roles of P. planifrons differed, with implications for the interpretation of diet studies and understanding of the role of omnivores in food webs. Речной рак: роль в экосистеме, Н.Зеландия02.01-04А2.92. Роль речного рака Paranephrops zealandicus как обкусывателя листьев в верховьях новозеландских ручьев. The significance of the crayfish Paranephrops zealandicus as shredders in a New Zealand headwater stream / Usio Nisikawa, Townsend Colin R. // J. Crustac. Biol. - 2001. - 21, № 2. - С. 354_ѕ359. - Англ. Полевое исследование 30 заводей в верховьях ручья Поудер-Крик, пров. Отаго, Н. Зеландия, показало, что речной рак P. zealandicus доминирует среди функциональной пищевой гильдии обкусывателей листьев, составляя по биомассе 99% беспозвоночных гильдии. На 2-м месте плекоптера Austroperla cyrene (0,62%). Лаб. эксперимент с плекоптерами и 2 размерными классами раков показал, что скорость переработки листьев на единицу веса тела у крупных раков ниже, чем у мелких и у плекоптер, но их влияние на разложение листьев и образование взвеси выше вследствие их большого веса и доминирования среди членов гильдии по биомассе. Речные раки в Н. Зеландии и, вероятно, повсюду в мире, могут играть ключевую роль в переработке листьев в верховьях ручьев, особенно там, где численность и биомасса насекомых невелики. Н. Зеландия, Dep. of Zoology, Univ. of Otago, POB 56, Dunedin. Ил. 2. Табл. 2. Библ. 27. Креветки: влияние на водоросли в разных масштабах.Pringle C M. Atyid shrimps (Decapoda: Atyidae) influence the spatial heterogeneity of algal communities over different scales in tropical montane streams, Puerto Rico. Freshwater Biology 35(1). 1996. 125-140. 1. Atyid (Decapoda: Atyidae) shrimps influence the distribution of algal communities over different scales in tropical montane streams of Puerto Rico. Within pools of an atyid-dominated stream, atyid shrimps enhanced patchiness in algal communities along the depth gradient. Algal bands occurred in shallow pool margins where atyids did not forage ( lt 3 cm below water surface), with significantly greater standing crop, taxon richness, and structural complexity than deeper areas. In deeper water, atyids reduced small-scale patchiness in algal community composition and maintained a low-growing understorey turf dominated by sessile diatoms (Bacillariophyta) and, sometimes, closely cropped, filamentous blue-greens (Cyanophyta). 2. Among pools of the atyid-dominated stream, atyids interacted with light to determine algal patchiness between stream margins and deeper areas. In sunny pools, algal standing crop was 140-fold greater in pool margins than in deeper areas where atyids foraged. In shaded pools, however, standing crop in pool margins was only 5-fold greater than in deeper areas. Effects of light on algal standing crop were greater outside atyid foraging areas than within, indicating that shrimp grazing overrides the positive effects of light. 3. In contrast to the atyid-dominated stream, algal communities in an atyid-poor stream were characterized by a high biomass of loosely attached epipelic diatoms and no depth zonation. Interstream rock and shrimp transplant experiments indicated that atyids significantly reduced algal standing crop and altered community composition on rocks from atyid-poor streams within 24 h. Results support the hypothesis that atyid shrimps play a major role in determining observed interstream differences in algal communities. Креветки: влияние засухи в реке, Пуэрто-Рико04.02-04А2.128. Влияние очень низких скоростей течения на пресноводных креветок в постоянной тропической реке. Effects of extreme low flow on freshwater shrimps in a perennial tropical stream / Covich A.P., Crowl T.A., Scatena F.N. // Freshwater Biol. - 2003. - 48, № 7. - С. 1199_ѕ1206. - Англ. Низкий уровень атмосферных осадков в 1994 г. в р-не Пуэрто-Рико привел почти к полному пересыханию перекатов тропической реки, изолированию отдельных плесов друг от друга, сокращению их объема и потери ряда биотопов для донных беспозвоночных. С 1992 по 1998 гг. каждые 2 мес. в 6 плесах реки на высоте 305_ѕ480 м над ур. моря на 1200-м отрезке изучали популяции креветок. После уменьшения размеров и глубины плесов в верхнем течении реки средняя плотность доминирующего вида Atya lanipes возросла с 22 до 75 экз./м{2} в засушливый 1994 г. Плотность Xiphocaris elongata увеличивалась с 5 до 14 экз./м{2}. В 1995_ѕ1998 гг. плотность обоих видов достигла прежних величин. Репродуктивная активность A. latipes также восстановилась, а X. elongata оставалась ниже, чем в период до засухи. Обсуждаются возможные последствия засухи для речных экосистем тропического дождевого леса при климатических сдвигах. США, Inst. of Ecol., Univ. of Georgia, Athens, GA 30602_ѕ2202. E-mail: alanc@uga.edu. Ил. 4. Библ. 34. Бокоплавы: влияние минерализации.Freshwater Biology Volume 39 Issue 1 Page 41 - February 1998 Ecophysiological diversity of alpine populations of Gammarus lacustris in relation to environmental calcium J. -C. Meyran 1. The contribution of environmental calcium to ecophysiological diversity among populations of Gammarus lacustris was investigated by comparing five alpine lakes in France. 2. Calcium concentrations in the water varied with substratum lithology, ranging from 6mgL1 in lakes on crystalline (igneous) rocks to 32.7mgL1 in lakes on limestone, and up to 248mgL1 in a lake with a gypsum environment. 3. The duration of the moult cycle and mortality rate were compared between populations by means of field and in situ laboratory and translocation experiments on adult males. Animals from water with low calcium concentrations showed a significantly longer moult cycle and higher mortality rate than those from water with high calcium concentrations. A significant increase in the duration of the moult cycle was observed in animals translocated to water of lower calcium concentration and viceversa. 4. These results suggest the existence of different physiological races of G.lacustris with an ecophysiological plasticity of calcium metabolism narrower than that of river-dwelling gammarids such as G.fossarum. This may be a consequence of geographic isolation among lacustrine populations together with the relatively stable environmental parameters in lakes.
Бокоплавы: КаспийDerzhavin A.N., Pjatakova G.M. 1997. A new species of the genus Stenogammarus Martynov, 1924 (Crustacea Amphipoda Gammaridae) from the Caspian Sea // Arthropoda Selecta Vol.5 (for 1996). No.3–4: 23–25 [in English]. Gammarus fossarum, питание02.06-04А2.175. Пищевая активность Gammarus fossarum (Crustacea, Amphipoda) в реке с кислой водой и низкой минерализацией воды. Feeding activity of Gammarus fossarum (Crustacea: Amphipoda) in acidic and low mineralized streams : Докл. _[27 Congress of the International Association of Theoretical and Applied Limnology, Dublin, 1998_] / Dangles Olivier J., Guerold Francois A. // Verh. / Int. Ver. theor. und angew. Limnol. - 2001. - 27, № 5. - С. 3062_ѕ3065. - Англ. Исследования проводили в трех горных реках в апреле 1998 г. Вода рек характеризуется низким рН, низкой электропроводностью, низким содержанием Cu и относительно высоким Al. Питание Gammarus fossarum изучали в лаб. Отмечено почти полное прекращение питание гаммаруса листьями, находящимися в воде кислой реки, по сравнению с контролем. Интенсивность питания листьями из очень кислой воды снизилась в 113 по сравнению с контролем. Нахождение листьев в слабой кислой воде такого резкого снижения питания не вызывало. Обсуждаются причины этого, в частности, прямое токсичное действие воды на гаммарид и косвенное, через пищу, путем влияния на микроорганизмы. Швеция, Animal Ecol. Dep. of Ecol. and Environmental Sci., Umea Univ., SE 90187 Umea. E-mail: o.dangles@wanadoo.fr. Ил. 1. Табл. 1. Библ. 26. Ракообразные: экология метаморфоза DiaptomusOikos Volume 97 Issue 2 Page 213-222 - May 2002 Fitness consequences of the timing of metamorphosis in a freshwater crustacean Saran Twombly and Nancy Tisch Metamorphosis is a common life-cycle transition in organisms as diverse as amphibians, insects, fishes and crustaceans, and the timing of this transition often affects an individual's fitness. Here, we measured age and size at metamorphosis in laboratory-reared individuals of the freshwater copepod, Diaptomus leptopus, and then followed individuals over their entire life cycle to assess the fitness consequences of variation in age and size at metamorphosis. In 3 separate experiments, individuals were raised in different food conditions: low food (0.2 g C/ml) switched to high food (0.7 g C/ml), or high food switched to low food, at several different larval and juvenile stages. Control individuals were reared on high or low food concentrations over their entire life cycles. For each individual, we measured age and size at metamorphosis and age and size at maturity; for females, we also measured total lifetime egg production, longevity, and calculated a composite fitness measure, . Statistical analyses showed no significant effects of age or size at metamorphosis on these same traits measured at maturity, or on the fitness components we estimated. The first individuals to mature had the highest total egg production and individual fitness; differences in body size at maturation explained none of the variation observed in fitness components. Our results show that metamorphosis was uncoupled from maturity and from fitness components by growth and development achieved during the juvenile phase of the life cycle, and support the conclusion that fitness consequences of metamorphosis depend fundamentally on the organization of an organism's life cycle. They also suggest that body size plays a different life-history role in these organisms than is recognized in most poikilotherms, and suggest the hypothesis, based on laboratory experiments, that selection may act primarily on juvenile developmental rates in field populations.
Volume 44 Issue 1 Page 63 - May 2000 The biology and ecology of lotic microcrustaceans M. -J. Dole-Olivier*, D. M. P. Galassi, P. Marmonier and M. Creuze Des Chatelliers* Summary 1. Copepoda, Ostracoda and Cladocera are important meiobenthic Crustacea which can be both numerically abundant and species rich in running waters. Harpacticoids and ostracods are well adapted to benthic life because they are typical crawlers, walkers, and burrowers. Many cladocerans are substratum dwellers, but most benthic species among these can also swim. Cyclopoids which are generally good swimmers are nevertheless often bottom frequenters and actively colonise sediment interstices (the hyporheic zone). 2. The subclass Copepoda includes 10 orders. With 53 families, the order Harpacticoida dominates the benthos. Only five of these families are represented in fresh waters (ca. 1 000 species and subspecies). The order Cyclopoida includes 12 families of which the Cyclopidae is well represented in freshwater habitats with 900 species and subspecies. Freshwater Ostracods belong to the order Podocopida (5 000 species) with three superfamilies occurring in running fresh waters. The group Cladocera contains four orders, 12 families, more than 80 genera, and 450-600 freshwater species. Most of the benthic species are found in the families Chydoridae (39 genera), Macrothricidae, Ilyocryptidae and Sididae. 3. For each of the three major taxa, morphological characteristics are presented, specimen collection and preparation are described and references to available taxonomical keys are provided. 4. Biological characteristics are extremely diverse among and within the three taxa, resulting in a great variety of strategies in meiobenthic crustaceans. Characteristics of reproduction, sexual dimorphism, cyclomorphosis and population parameters (i.e. clutch size, lifespan, growth, moulting) are provided for some of the most common species. 5. Important differences between the three main taxa were found at the species level. Ecological requirements such as hydraulic microhabitats and geomorphologic features of the streambed are the major determinants of species diversity and abundance for benthic microcrustacea of lotic habitats. Many studies on the ecology of these communities are limited by a lack of knowledge of the life history characterisitics of lotic (especially interstitial) crustacean populations.
жүктеу/скачать 1.21 Mb. Достарыңызбен бөлісу:
|