云南省丽江苔藓中缓步动物(异缓步纲:棘节目:棘影熊虫科;真缓步纲:近爪目:大生熊虫科,高生熊虫科)

记述了采自云南省丽江县的缓步动物13种,包括：安哥拉棘影熊虫Echiniscus angolensis da Cunha etal,凹口棘影熊虫Echiniscus cavagnaroi Schuster,米吉棘影熊虫Echiniscus migiurtynus Franceschi,华美假棘影熊虫Pseudechiniscus facettalis Petersen,丽江苔小猪熊虫Bryodelphax lijian-gensis sp.nov,隐匿大生熊虫Macrobiotus adelges Dastych,云杉大生熊虫Macrobiotus yunshanensis sp.nov,华丽大生熊虫Macrobiotus richtersiJ.Murr,双甲高生熊虫Hypsibius biscuitiformis Bartos,锐齿高生熊虫Hypsibius runae Bartos。棒形双相熊虫Diphascon clavatum(Bartos)。云南等高熊虫Isohypsibius yunnanensis spnov,隆肿等高熊虫Isohypsibius tuberculatus(Plate)。本文所用标本均保存在中国科学院水生生物研究所。     

Predicting and testing functional responses: An example from a tardigrade–nematode system

Numerous studies have empirically measured consumer functional responses or theoretically developed response models, but whether these models can quantitatively predict observed data has hardly been tested. We perform such a test for the terrestrial predator–prey system Macrobiotus richtersi (Tardigrada)–Acrobeloides nanus (Nematoda). For two different size classes of A. nanus, we report a functional response as measured in the laboratory and quantitatively compare it to predictions of three models with different degrees of complexity: (1) the disc equation which does not include satiation effects; (2) the steady-state satiation (SSS) equation which assumes a constant level of predator satiation; and (3) the satiation model which accounts for prey depletion and increasing predator satiation over the course of the experiments. We parameterized these models with data that were measured independently of the functional response experiments. In both prey-size classes, the predictions of the satiation model matched the observations best, and the match came close to that of logistic regressions fitted to the observations. Thus, the parameterized satiation model seems to include the most important determinants of the functional response in our focal system. For understanding functional responses, we need more studies that compare data to independently derived model predictions.     

DNA barcoding in Tardigrada: the first case study on Macrobiotus macrocalix Bertolani & Rebecchi 1993 (Eutardigrada, Macrobiotidae)

Morphological and molecular studies on a tardigrade species have been carried out to verify the possibility of using a DNA barcoding approach for species identification in this phylum. Macrobiotus macrocalix Bertolani & Rebecchi, 1993 was chosen as the test species since it belongs to a group of species in which the taxonomy is quite problematic. Animals and eggs belonging to three Italian and one Swedish populations have been investigated. Both morphological and molecular analyses show that all the populations belong to the same species. The low genetic distances recorded among the studied populations (0.3-1.0%) and the high genetic distance (15.9-16.3%) between these populations and a closely related species confirm the possibility of identifying a specimen of this species by its cytochrome oxidase subunit I sequence. Data from other authors support our results indicating that DNA barcoding can be applied to tardigrades. With our protocols, we have obtained voucher specimens that enable us to show a correspondence between morphology and molecular data.     

Comparative studies on storage cells in tardigrades during starvation and anhydrobiosis

The impact of starvation and anhydrobiosis on the number and size of the storage cells in the tardigrade species Milnesium tardigradum, Paramacrobiotus tonollii and Macrobiotus sapiens was investigated to gain more insight on the energetic side of anhydrobiosis. Storage cells are free floating cells within the body cavity of tardigrades and are presumed to store and release energy in form of glycogen, protein and fat to maintain a constant nutrient regime for the other tissues. The body size of the animals was not correlated with the size of the storage cells, however, M. tardigradum the largest species analysed also had the largest storage cells. A reduction in the size of the storage cells is apparent in all three species after seven days of starvation. A seven-day period of anhydrobiosis leads to a decrease in cell size in M. tardigradum but not in P. tonollii and M. sapiens. Although M. sapiens was raised on green algae, and M. tardigradum and P. tonollii were fed with rotifers and nematodes this difference in nourishment was not reflected in the response of the storage cells to anhydrobiosis.     

温度和热驯化对胡氏大生熊虫运动行为的影响

对外温脊椎动物体温和运动能力关系的研究表明,外温动物的运动行为对身体温度的变化高度敏感(Bennett,1990)。在许多动物种类中,体温的升高或降低显著影响动物的运动能力(Huey,1982;Miller,1982;Watkins,2000),而运动能力的下降则影响外温动物逃避捕食者(Christian andTracy,19     

Phenotypic Variations in the Life History of Two Clones of Macrobiotus richtersi (Eutardigrada, Macrobiotidae)

A comparative study of life history traits of two clones (CDMr01 and CDMr02) of a triploid thelytokous apomictic population of the eutardigrade Macrobiotus richtersi has been carried out. Both clones were reared under the same lab conditions: temperature of 14 °C, photoperiod of 12 h/12 h (L/D), and nematodes ad libitum as food. Statistical analysis of the life history traits considered has indicated interclonal variability. The two clones were significantly different in the number of eggs per clutch (fertility), number of eggs laid per female per life span (fecundity), hatching percentage of eggs and hatching time. Similarities between clones have been observed with regard to life span, total number of ovipositions per life span, and age at first oviposition. In addition, significant differences in hatching time, with eggs hatched over a long period, were found within each clone. Interclonal variability in life history traits indicated the effects of genetic factors, whereas intraclonal variability reflected the effects of environmental factors. The evolutionary and adaptive significance of the life history phenotypic variations is discussed.     

Effect of temperature and thermal acclimation on locomotor performance of Macrobiotus harmsworthi Murray (Tardigrada, Macrobiotidae)

We investigated the effects of acute and acclimation temperature on the locomotor performance and behavior of the tardigrade Macrobiotus harmsworthi collected from Qinling Mountains in central China. Tardigrades were acclimated to either 10 or 25 °C for 2 weeks. Then we recorded their walking speed, percentage of time moving, and the maximum distance covered by continuous locomotion at either 10 or 25 °C as the rate parameters of locomotor performance. The walking speeds of M. harmsworthi varied from 1.98 to 4.8 mm min^–1. The locomotor performance rates were significantly influenced by both acclimation temperature and performance temperature and by the interaction of the performance temperature and acclimation temperature. The data from our studies support the Beneficial Acclimation Hypothesis (BAH) which predicts that animals acclimated to a particular temperature have enhanced performance or fitness at that temperature in comparison with animals acclimated to other temperatures. The data, at least potentially, also support the Warmer is Better Hypothesis which predicts that organisms raised at high temperatures have higher relative fitness across all temperatures than do those raised at intermediate or cool temperatures. Some of the results from our studies testify the inference from the BAH that performance temperature that deviates from the acclimation temperature could cause the reduction of the locomotor performance rate.     

中国缓步动物门二新种及三新纪录种和亚种(异缓步纲,棘影熊虫科;真缓步纲,小斑熊虫科,大生熊虫科,高生熊虫科)

记述采自河南省洛阳市、湖北省京山县和四川省都江堰市的缓步动物门2新种及3新纪录种和亚种：异缓步纲棘影熊虫科的四棘棘影熊虫,新纪录Echiniscus quadrispinosus Richters,1902;真缓步纲小斑熊虫科的都江小斑熊虫,新种Milnesium dujiangensis sp.nov,大生熊虫科的节值大生熊虫戴冠亚种,新纪录Macrobiotus harmsworthi coronatus Barros,1942;高生熊虫科的大指等高熊虫,新纪录Isohypsibius macrodactylus(Maucci,1978)和京山等高熊虫,新种Isohysibius jingshanessis sp.nov.     

A new species of the genus Macrobiotus(Tardigrada:Macrobiotidae) from Southeastern China

A new species Macrobiotus wuyishanensis sp.nov.(Tardigrada:Macrobiotidae) is described from Mt.Wuyi,Southeastern China.It is most similar to Macmbiotus spectabilis Thulin,1928,but differs by lacking fine punctuation on the distal half of the projections on the egg,a ring of polygons that circle the base of each projection,and punctation between the projections on the egg shell.It is also similar to M.grandis Richters,1911,but differs by smaller body size,lacking polygons and punctations between the projections on egg shell.