The genus Cremastra (Orchidaceae), a taxonomic revision

The genus Cremastra is revised. A total of 8 taxa have earlier been proposed, but in the present revision 2 species are recognized: C. appendiculata and C. unguiculata. Hyacinthorchis variabilis is here considered a variety: C. appendiculata var. variabilis comb. et stat. nov.     

Three new species of Caulokaempferia (Zingiberaceae) from Thailand with a discussion of the generic diversity

Three new species of Caulokaempferia from Thailand, C. appendiculata, C. bracteata , and C. violacea , are described and illustrated. The diversity of genus is discussed. A key to the species known from Thailand is provided.     

The dynamics of infection of Diphyllobothrium dendriticum (Nitzsch) and D. ditremum (Creplin) in the char Salvelinus alpinus (L.) in Sweden

A total of 654 char, Salvelinus alpinus (L.), from Lake Bjellojaure, Sweden, were examined for plerocercoids of Diphyllobothrium dendriticum (Nitzsch, 1824) and D. ditremum (Creplin, 1825) from September 1969 to December 1974. Plankton samples showed that the dominating copepod species in the lake were Eudiaptomus graciloides (Lilljeborg), Cyclops scutifer Sars and Heterocope appendiculata Sars. E. graciloides passed the winter as adults and C. scutifer as copepodids while H. appendiculata was restricted to a short period in the summer. Copepods occurred in the stomachs in September-October and to a certain extent in April-May, but only cyclopids and Heterocope sp. were found. C. scutifer is proposed to be the main first intermediate host of both D. dendriticum and D. ditremum . The potential final hosts were thecommon gull, Larus canus L., for D. dendriticum and the black-throated diver, Gavia arctica (L.), for D. ditremum . One common gull was experimentally successfully infected with plerocercoids of D. dendriticum . The parasites showed no seasonal cycle in incidence of infection.     

洛阳地区黄胸木蜂访花植物种类及访花行为

【目的】明确黄胸木蜂Xylocopa appendiculata的访花植物种类和访花行为, 为进一步开发和利用木蜂资源奠定基础。【方法】 2009-2011年连续3年, 在洛阳地区黄胸木蜂的活动期3-10月, 采用目测、 拍照等方法记录其访花植物及访花行为, 记录和统计访花植物的生物学特征; 测量访花植物种类被盗蜜后盗蜜口的大小。【结果】在洛阳地区黄胸木蜂访花植物种类为27科52种, 主要的访花植物有25种。采访的植物种类中, 忍冬科和豆科植物最多, 分别为9种和8种, 占采访植物种类的17.31%和15.38%; 其中黄胸木蜂盗蜜的植物有16种, 占其采访植物种类的30.77%。在采访的植物种类中, 黄胸木蜂喜欢采访中等花型、 两侧对称的紫色、 黄色和白色花。在不同植物上, 黄胸木蜂的盗蜜口大小和访花频率不同, 黄胸木蜂在臭牡丹上的盗蜜口最大, 为9.43±1.91 mm, 蝟实上的盗蜜口最小, 为3.46±0.98 mm; 在紫薇上的访花速度最快, 访花频率为25.71±2.36朵/min; 在蜀葵上的单花停留时间和访花间隔时间均最长, 单花停留时间5.89±3.34 s, 访花间隔时间为2.63±2.04 s。【结论】在洛阳地区黄胸木蜂访花植物种类多、 访花时间长。对于不同的植物种类, 黄胸木蜂的访花行为和访花频率有差异。     

Stage-dependent predation on competitors: consequences for the outcome of a mosquito invasion

1. Predator-mediated coexistence occurs when predation allows competitors to coexist, due to preferential consumption of a superior competitor relative to an inferior competitor. Differences between the native treehole mosquito ( Aedes triseriatus ) and the co-occurring Asian tiger mosquito ( Aedes albopictus ) in anti-predatory larval behaviours account, in part, for the greater vulnerability of this invasive species to native predatory midge ( Corethrella appendiculata ). We test the hypothesis that stage-dependent differences in the sizes of A. albopictus and A. triseriatus larvae, relative to the size-limited C. appendiculata , contribute to differential consumption and the likelihood of predator-mediated coexistence of these competitors.
2. In all instars, larvae of A. triseriatus were larger than A. albopictus of the same stage. Third and fourth instar C. appendiculata selectively consumed late-stage A. albopictus in preference to same-stage A. triseriatus . Small, early-stage prey larvae did not differ in vulnerability to predation, but large, late-stage larvae differed significantly in vulnerability to predation, probably owing to size-limited predation by fourth instar C. appendiculata. This effect was less pronounced for third instar C. appendiculata .
3. Prey size, in conjunction with anti-predatory behavioural responses, alters the probability of predator-mediated coexistence. A stage-structured predation model showed that equally vulnerable early stages reduce the range of environmental conditions (productivities) in which predator-mediated coexistence is possible, increasing the likelihood of both competitive exclusion of the resident species or failure of the invasive to establish. These results underscore the importance of stage-dependent interspecific differences in predator–prey interactions for determining how predators may affect community composition.     

Helminths of the horned leaf frog, Proceratophrys appendiculata, from southeastern Brazil

The helminth fauna of the horned leaf frog, Proceratophrys appendiculata (Anura: Leptodactylidae), was studied from 17 adult individuals from an island in Rio de Janeiro state, southeastern Brazil. A total of five nematode species (Aplectana delirae, Cosmocerca brasiliense, Schulzia travassosi, Rhabdias androgyna and Physaloptera sp.) and an unidentified cestode were recovered from the digestive tract, lungs and gall bladder of P. appendiculata and all the nematode species are new host records. Aplectana delirae had the highest values for the prevalence and intensity of infection and can thus be considered a core species in the helminth community of P. appendiculata. Aplectana crossodactyli Baker, 1980 is synonymized with Aplectana delirae (Fabio, 1971). The helminth fauna of P. appendiculata presents characteristics typical of those in amphibians.     

Behavioural responses of larval container mosquitoes to a size-selective predator

Abstract.  1. The hypothesis that size-selective predation and species-specific prey behaviours facilitate the coexistence between larvae of invasive Aedes albopictus (Skuse) and U.S.A.-native Ochlerotatus triseriatus (Say) was tested experimentally with the predator Corethrella appendiculata (Grabham).
2. Larval behaviours associated with a higher risk of predation were identified, and prey behavioural responses were tested in either the physical presence of predators or in water containing predation cues. Larvae that thrashed on container bottoms had a higher risk of being captured by fourth instar C. appendiculata than did larvae resting on the water surface. Ochlerotatus triseriatus , but not A. albopictus , adopted low-risk behaviours in response to water-borne cues to predation. Both prey species reduced risky behaviours in the physical presence of the predator, but O. triseriatus showed a stronger response.
3. The vulnerability of 2nd and 3rd instar prey to predation was compared, and behavioural responses were correlated with prey vulnerability. Second instars of both species were more vulnerable to predation by C. appendiculata than were 3rd instars, and the 3rd instar A. albopictus was more vulnerable than O. triseriatus of the same stage. All instars of O. triseriatus showed a similar reduction of risky behaviours in response to the presence of C. appendiculata despite 4th instar prey being relatively invulnerable to size-selective predation.
4. Weaker predator avoidance, coupled with superior competitive ability, of invasive A. albopictus is likely to contribute to its coexistence with O. triseriatus in containers of the south-eastern U.S.A., where C. appendiculata can be abundant.     

贵州兰科新资料

报道了贵州兰科2个种。贵州杜鹃兰Cremastra guizhouensis Q.H.Chen&S.C.Chen系一新种,与杜鹃兰C.appendiculata（D.Don）Makino相近,区别点在于本新种具长达10-14cm的圆筒状假鳞茎和在唇瓣中裂片上有1枚平滑的胼胝体。另一个种为线叶美冠兰Eulophia siamensis Rolfe ex Downie,首次报道也产于中国。     

Patterns of swimming of cercariae in some trematode species

Swimming activity of cercariae in the trematode species Cryptocotyle lingua, Himasthla elongata, Maritrema subdolum, and Cercaria parvicaudata (Renicola sp.) is studied using video microfilming. The larvae of C. lingua demonstrate a typical intermittent swimming with regularly alternating periods of active movement and passive floating. The duration of both periods during the first 30 min of cercaria's life retains equal, and later the passive period becomes longer. In 15 h the duration of the active period is 0.5-1 s and the passive one--20-30 s. The cercariae of H. elongata during the first 10-15 min of their free life make short stops (1-2 s) in every 10-15 s of swimming. Later these stops become rare and their duration reduces to 0.5-1 s. The cercariae of M. subdolum and C. parvicaudata are continuous swimmers, having left the molluscan host they move persistently. If stops take place they are very rare (one case in 5-15 min) and very short (0.5-1 s). The movements of cercariae body and their tail during swimming are similar in all species studied. The proximal part of the tail undulates in lateral plane, and the middle and distal parts of this organ in the top view circumscribe a figure of eight. In the side view the middle and distal parts of the tail being rotate form a figure like a screw. The cercariae move along the screw axis. The linear swimming rate in the beginning of cercariae's life is 4.8 mm/s for C. lingua, 2.4 mm/s for H. elongata, and 0.35 mm/s for M. subdolum and C. parvicaudata. By the aging the cercariae swimming rate decreases down to the full cease of swimming activity, and the larvae sediment onto the bottom. The age dynamics of swimming rate is different in cercariae of different species and is determined by the morphological functional features of the larvae.     

Effects of hemolymph of the American oyster, Crassostrea virginica, on marine cercariae

The interactions of cellular and humoral factors of hemolymph of the American oyster, Crassostrea virginica, and several species of marine cercariae were studied. Attraction of hemocytes to dead but not to living cercariae was observed. Dead cercariae were encapsulated in vitro by oyster hemocytes. The plasma of C. virginica was apparently not toxic to the species of cercariae tested.     

Sensory system of 2 species of cercariae of the genus Cryptocotyle (Trematoda, Heterophyidae)

The sensory system of two species of cercariae of the genus Cryptocotyle, C. concavum and C. lingua, is described and differences are indicated in the location of sensillae of both species which make possible the clear differentiation of both species.     

Laboratory Studies of Parasite Transmission Aspects between Hydrobia spp. (Gastropoda) and Corophium volutator (Amphipoda)

Aspects of parasite transmission between Hydrobia spp. and Corophium volutator, first and second intermediate host of digenetic trematodes, were investigated under laboratory conditions. H. ventrosa is used as an intermediate host by several trematode species. Under laboratory conditions the most frequently observed emergence from H. ventrosa was of cercariae of Maritrema subdolum. The number of cercariae shed per day varied considerably. It was observed that 30 cercariae on average and up to 450 cercariae at maximum can emerge from a single H. ventrosa per day. Cercarial production continued until the death of the snails. The life-span of cercariae of the species M. subdolum decreased as the water temperature increased. It can be concluded that under natural conditions the cercariae, after emerging, have a maximum period of 1 day in which to seek out their second intermediate host C. volutator. Almost all specimens of C. volutator exposed to cercariae of the species M. subdolum died within the test period of 6 days. High average cercarial densities caused short life-spans (<50 h), while at lower densities longer survival times were possible. For cercariae of other Trematoda species, we were unable to find any equally clear evidence of a reduction in the survival rate of C. volutator within the test period. Mortality of C volutator, and other effects of infestation, as observed in our experiment, can be assumed to be a result of the penetration process of the cercariae but they also can be attributed to the mesocercariae.     

Food and growth of age-0 smelts, Osmerus eperlanus, in a Norwegian fjord lake

Pennate diatoms, especially Aslerionella spp. and Tabellaria fenestrata , were the most important food items for smelts in Lake Mjøsa during the first month of external feeding; rotifers and early stages of copepods were eaten occasionally. Later, during summer and autumn, crustacean zooplankton (cladocerans and copepods) were the most important food items; selected species were Polyphemus pediculus, Eudiaptomus gracilis, Limnocalanus macrurus, Heterocope appendiculata. Leplodora kindti , and Bythotrephes longimanus ; some smelts larger than 7.4 cm fed on Mysis relicta . In 1979 and 1980, mean lengths of smelts in October-November were 4.7 cm and 7.2 cm, respectively. A difference in length increment between the two years may have resulted from summer water temperatures being higher in 1980 than in 1979.     

Contribution of pollinators to seed production as revealed by differential pollinator exclusion in Clerodendrum trichotomum (Lamiaceae)

A diverse assemblage of pollinators, such as bees, beetles, flies, and butterflies, will often visit a single plant species. However, evaluating the effect of several insects on fruit and seed production is difficult in plants visited by a variety of insects. Here, we analyzed the effect of three types of pollinators, Papilio spp., Macroglossum pyrrhosticta, and Xylocopa appendiculata on fruit and seed production in Clerodendrum trichotomum by using a flower visitor barrier experiment with nets of specific mesh sizes. As a result, fruit/flower and seed/ovule ratios were significantly lower under Papilio exclusion than under natural conditions. On the other hand, ratios were not significantly different between Papilio excluded and both Papilio and M. pyrrhosticta excluded treatments. Therefore, Papilio and X. appendiculata are effective pollinators, whereas M. pyrrhosticta, which was the most frequent visitor, of C. trichotomum, is not. From our observations of visiting behaviors, we believe that because M. pyrrhosticta probably promotes self- pollination, this species is a non-effective pollinator. This is the first study to separate and compare the contribution of various visitors to the reproductive success of a plant.     

Redescription of Tejidotaenia appendiculata (Baylis, 1947) (Cestoda: proteocephalidea), a parasite of Tupinambis teguixin (Sauria: teiidae) from South America

The species Tejidotaenia appendiculata (Baylis, 1947), a parasite found in teju, Tupinambis teguixin is redescribed and a new diagnosis is provided. The species is characterized by the anterior position of the ovary and the peculiar shape of suckers. It is the first record of this species in Brazil.     

Respiration and motor activity of cercariae of three trematode species from the intertidal mollusc Littorina littorea L (Gastropoda) from the White sea

The age dynamics in oxygen consumption of the cercariae Himasthla elongata, Cryptocotyle lingua and Cercaria parvicaudata (Renicola sp.) was studied using modified Winkler's method. It was detected that under stable temperature and water salinity conditions the rate of oxygen uptake depends directly on cercariae size. The highest intensity of energetic metabolism was recorded in the first few hours of cercariae life when their movement activity was maximal. The following reduction of oxygen consumption passed unequally in three cercariae species studied. Large, long-lived H. elongata cercariae after relatively short period of active swimming turn to crawling on the bottom. The rate of oxygen uptake in such cercariae was two times less than in free-swimming ones and remained approximately invariable up to the cercariae death. The smaller sized, short-lived Renicola sp. cercariae swim actively in the water and during this time the level of their energetic metabolism remains more or less stable. It decreased drastically after cercariae sinking to the bottom, after that they perished very soon. Also relatively small C. lingua cercariae alternate the active and passive phases of swimming. Thanks to that they consume the energetic resources economically and prolong their longevity. During free-swimming period the rate of oxygen uptake of C. lingua cercariae remains more or less stable. As in the case of Renicola sp. cercariae, it decreased drastically after the cercariae sinking to the bottom. Apparently such cercariae lose their ability to infect the second intermediate host (fish).     

The influence of salinity on the cercariae of three species of Schistosoma

Donnelly F. A., Appleton C. C. and Schutte C. H. J. 1984. The influence of salinity on the cercariae of three species of Schistosoma. International Journal for Parasitology14: 13–21. The effect of salinity on the longevity and infectivity of cercariae of Schistosoma mattheei, Schistosoma haematobium and Schistosoma mansoni was determined. No significant differences in cercarial longevity occurred (p > 0.05) in low salinities (0–5.25%), whereas further increases in salinity resulted in progressive decreases in survival. In salinities ? 17.5%, cercariae were incapable of surviving for longer than 11 min. A maximum life-span of up to 122 h was recorded for some S. mattheei cercariae. Cercarial infectivity, as indicated by worm returns, was reduced progressively with increasing salinity up to a lethal limit of 10.5%. Differences in the salinity tolerance of the cercariae of the three species were discussed.     

The morphology, ontogeny, and small subunit rRNA gene sequence analysis of Diophrys parappendiculata n. sp. (Protozoa, Ciliophora, Euplotida), a new marine ciliate from coastal waters of southern China

The morphology, morphogenesis, and phylogeny of Diophrys parappendiculata n. sp., a large marine ciliate isolated from the coastal waters of Daya Bay, southern China, were investigated. This new species is characterized by a combination of its large size, appendiculata-pattern of ciliature, and bipartite adoral zone of membranelles. The main stages of morphogenesis during binary fission were also recorded and described. Comparisons of morphological characteristics with similar congeners support the validity of the new species. The small subunit rRNA gene sequence of D. parappendiculata is 96.3-99.94% similar to those of four other congeners; it differs in four nucleotides from that of Diophrys appendiculata (i.e. structural similarity was 99.94%). Phylogenetic analysis indicates that D. parappendiculata n. sp. falls into the Diophrys clade and is most closely related to the well-known D. appendiculata.     

Phenotypic plasticity of six unusual cercariae in nassariid gastropods and their relationships to the Acanthocolpidae and Brachycladiidae (Digenea)

Species-level relationships of a complex of six putative acanthocolpid cercariae with ventral keels from nassariid gastropods from Capricornia, Queensland (Cercaria capricornia I–VI) were explored using mitochondrial and nuclear DNA sequence data. Analysis of the large subunit of nuclear ribosomal DNA (rDNA), the internal transcribed spacer 2 rDNA and subunit 3 of the nicotinamide-adenine-dinucleotide dehydrogenase mitochondrial gene indicates that the six distinct morphotypes previously identified relate to only three discrete genotypes. Consequently, the six cercarial morphotypes that were inferred to represent six species and distinguished previously based on morphology and behaviour, are considered here to be comprised of three species (i.e. Cercaria capricornia I and II are considered the same species, C. capricornia types III to V are considered to belong to a second species and C. capricornia VI is considered to comprise the third species in this complex). This recognition of reduced diversity following molecular analysis runs contrary to the more frequently reported uncovering of cryptic diversity, especially when larval trematodes are examined. Phylogenetic analysis of these morphologically unusual cercariae supports their inclusion in the Acanthocolpidae. Bayesian inference analysis identifies three distinct clades: (a) Stephanostomum + Monostephanostomum; (b) the Brachycladiidae and Pleorchis; and (c) Tormopsolus and the present cercariae. Genus-level identification of these cercariae remains uncertain given the current lack of available comparative genetic data on nucleic acid databases.