Molecular Phylogeography of Oncomelania Lindoensis (Gastropoda: Pomatiopsidae), the Intermediate Host of Schistosoma Japonicum in Sulawesi

Oncomelania lindoensis from Lake Lindu, Sulawesi, was characterizedfor genetic variation at 21 allozyme loci and compared withO. hupensis (China) and O. quadrasi (Philippines). Geneticdistances and interpopulation patterns of allele-sharing pointto a closer relationship between Sulawesi and the Philippines(Nei's unbiased genetic distances (D) averaged 0.50) than betweenSulawesi and China (D= 0.79). These data, coupled with a considerationof the geographic distribution of the genus, support the hypothesisthat the Sulawesi Oncomelaniaoriginated by avian-facilitated colonizationfrom the Philippines about two million years ago. Oncomelania from Sulawesi were originally described as subspecificallydistinct: Oncomelania hupensis lindoensis. However, the allopatricdistribution, unique alleles at five loci, and significant geneticdistances from congeners in Mindanao and elsewhere in the Philippinessuggest that this taxon should be distinguished as a full specieswithin the Oncomelania hupensis species group, namely: O. lindoensisDavis & Carney 1973. Comparison with published data on variationwithin quadrasi and in three Chinese subspecies of hupensisshowed that D values increase with taxonomic level in this speciesgroup. D averaged 0.15 (0–0.26) within Chinese subspeciesand 0.04 (0–0.13) within the Philippines, but was 0.30(0.20–0.45) between Chinese subspecies, and 0.48–0.80between the three species (hupensis, quadrasi and lindoensis).The genotypic cluster species concept and these multilocus geneticdistances can be used to help define species and subspeciesin these medically important snails. (Received 14 May 1997; accepted 20 April 1998)     

On the genetic diversity in the mitochondrial 12S rRNA gene of Platymantis frogs from Western New Guinea (Anura: Ceratobatrachidae)

Platymantis is a group of neobatrachian frogs that occurs from the Philippines to New Guinea – an area situated at the interface between the Australian and Asian biogeographical region that is highly fragmented by stretches of open sea. Partial sequences of the mitochondrial 12S rRNA gene are herein used to infer the relationships of species from the Indonesian part of New Guinea (Papua and West Papua Province). The phylogenetic trees reveal a deep bifurcation between the Asian and Western New Guinean clades being consistent with phylogeographic patterns observed in various other faunal groups. While most species are well differentiated in the examined locus, low interspecific genetic distances between one and three percent were observed in the New Guinean species Platymantis papuensis and P. cryptotis as well as P. pelewensis from Palau. Platymantis papuensis and P. pelewensis are geographically separated from each other by a 1100 km stretch of open sea. The minor degree of genetic differentiation between both species points to a recent event of transmarine dispersal as causation for the occurrence of P. pelewensis on Palau. The low genetic differentiation between P. cryptotis and the sympatric P. papuensis, two species that are bioacoustically and morphologically distinct, may indicate its possibly recent evolutionary origin or, alternatively, yet undetected hybridization between the two species. The same may also hold true for frogs from Yapen that exhibit calls different from the sympatric P. papuensis. Tentatively referred to as Platymantis spec., these frogs are also genetically not well differentiated. It is furthermore concluded that the partly low genetic differentiation of the New Guinean Platymantis species render this group one of the cases in which DNA barcoding would likely fail to produce reliable results.     

Microfungi on the Pandanaceae:Polytretophora macrospora sp. nov.

Polytretophora macrospora is introduced based on specimens from two species ofPandanus in Seychelles. The new species is compared with currently accepted species. A key and a comparative synopsis toPolytetophora species are provided. Numerous specimens ofP. calcarata, collected on members of the Pandanaceae from Australia, Fiji, Hong Kong, Malaysia, New Caledonia, Palau, Philippines, Seychelles and Solomon Islands are also reported, along withP. dendroidea onPandanus sp. from Malaysia.     

Life cycle strategies and seasonal variations in distribution and population structure of four dominant calanoid copepod species in the eastern Weddell Sea, Antarctica

The dominant Antarctic copepod species Calanoides acutus, Calanuspropinquus, Rhincalanus gigas and Metridia gerlachei were investigatedwith respect to their abundance, vertical distribution, developmentalstage composition, dry weight and lipid content. The specimenswere sampled during three expeditions to the eastern WeddellSea in summer (January/February 1985), late winter/early spring(October/November 1986) and autumn (April/May 1992) between0 and 1000 m depth to follow the seasonal development of thepopulations. Three species were most abundant in April, onlyC.propinquus reached highest concentrations in February. A seasonalmigration pattern was evident in all four species, but was mostpronounced in C.acutus. In October/November, they inhabiteddeeper water layers, their ascent started by mid-November andin mid-February the species concentrated in the upper 50 m,except for M.gerlachei (50–100 m). Their descent was observedin April/May. The stage composition changed dramatically withseason, the older developmental stages (CIII–CVI) dominatedthe populations in late winter/early spring, whereas youngerstages (CI and CII) prevailed during summer (C.acutus, C.propinquus)or autumn (R.gigas, M.gerlachei). Only C.acutus ceased feedingin autumn and diapaused at depth. Strong differences betweenseasons were also detected in dry weight and lipid levels, withminima in late winter/early spring and maxima in summer (C.acutus,R.gigas) or autumn (C.propinquus, M.gerlachei). Lipid reservesseem to be most important for the older stages of C.acutus andC.propinquus. Based on these seasonal data, different life cyclestrategies are suggested for the four species.     

Top-down impact by copepods on ciliate numbers and persistence depends on copepod and ciliate species composition

Experiments with the copepods Acartia clausi, Centropages hamatusand Pseudocalanus sp. were performed to assess the species-specificeffect of these copepods on the development of monospecificalgae (Nephroselmis pyriformis) and ciliate communities (Strombidiumvestitum, Strombidium conicum, Strombidium sp. and Lohmanniellaoviformis). It was hypothesized that potentially switching copepodslike A. clausi will stabilize the algal community by switchingbetween ciliate and algal food, in contrast to copepods withstereotypic filter feeding behaviour (Pseudocalanus sp.). Intreatments with Pseudocalanus sp. and C. hamatus, all ciliatespecies were wiped out in 2 days, resulting in blooms of N.pyriformis. In treatments with A. clausi, two of the ciliatespecies were able to persist, but the combined ciliate and copepodcommunity was not able to control the algal bloom. Ciliatesbecame abundant in control treatments without copepods, butonly S. vestitum and S. conicum seemed able to establish grazingcontrol. Hence, when evaluating the role of ciliates in foodwebs, their actual numbers and species composition should betaken into account. Likewise, the species composition of copepodsmay be crucial; these experiments demonstrate that small filterfeeding copepods may have tremendous impact on ciliate numbers.     

Le zooplancton de la baie de Sh?diac (Nouveau-Brunswick)

Analyses of boreal zooplankton of Shediac Bay demonstrate theabundance of copepods (81%) and meroplankters (18%). Whetherexclusively pelagic or not, 67 species are mentioned for thefirst time in this Northumberland Strait area, out of 76 recordedwithin 23 higher taxa. The fluctuations were observed from Mayto November and pointed out the dominance of such copepods asAcartia tonsa, A. clausi, Oithona similis and Centropages hamatusin relation with temperature, salinity and food distributions. ¹Adresse actuelle: Station marine de Tul?ar, B.P. 141, Universit?de Madagascar, (R?p. Malgache)     

Ultrastructural observations on marine choanoflagellates (Choano-flagellida, Acanthoecidae) from the coast of Thailand: species of Apheloecion gen.nov

Three species of loricate choanoflagellates (Choanoflagdlida,Acanthoecidae), collected from the Andaman Sea near Phuket Island(SW Thailand), have been described and referred to Apheloeciongen.nov. (holotype: A. quadrispinum sp.nov.). All species possessa single-chambered lorica composed of one transverse costs overlaidby a limited number of longitudinal costae which converge posteriorly.Anteriorly the longitudinal costae protrude above the transversecosta as sharp pointed spines. In A. quadrispinum sp.nov. andA. pentacanthum sp.nov. the lorica is terminated by a shortposterior spine, whereas in A. articulatum sp.nov. the pedicelis much more prominent, consisting of several costal stripswhich are joined end-to-end. The species of Apheloecion appearto be most closely related to species of Calliacantha and Monocosta.None of the species described are so far known from localitiesoutside the Andaman Sea.     

The effect of cadmium and lead on the growth of two species of marine phytoplankton with particular reference to the development of tolerance

Decreases in salinity (<10%) increased the growth rates ofPhaeodactylum tricornutum and Dunaliella tertiolecta. Increasinglevels of cadmium (1–50 ppm (mg 1^–1)) reduced thegrowth rates of both species. 100 ppm cadmium was lethal toD. tertiolecta but not to P. tricornutum. Lead (1 –4 ppm)initially increased the growth rate of D. tertiolecta but thencaused all but the 1 ppm culture to die. Lead (1–4 ppm)caused a decrease in growth rate of P. tricornutum. After exposureto 1 ppm cadmium, cultures of D. tertiolecta showed an increasedtolerance to levels of cadmium, and a changed response to levelsof lead. Exposure of P. tricornutum to either cadmium or lead,or exposure of D. tertiolecta to lead caused no change in responseto either metal.     

A monograph of the order Pyrosomatida (Tunicata, Thaliacea)

The taxonomy of the order Pyrosomatida is revised based on theexamination of over 300 samples from all parts of the worldoceans. The order consists of a single family (Pyrosomatidae),two subfamilies (Pyrostremmatinae and Pyrosomatinae), threegenera (Pyrostremma, Pyrosomdla and Pyrosoma) and 8 species(Pyrostremma spinosum, P. agassizi, Pyrosomella verticillata.P. operculata, Pyrosoma atlanticum, P. aherniosum, P. ovatumand P. godeauxi n.sp.). The species are briefly described anddata on their distribution are provided. A key to the speciesis given. A cladistic analysis of the distribution of relevantcharacter states is made and ideas on evolutionary developmentare put forward. Biogeographical data are summarized and inconjunction with that the likely modes of speciation in thisgroup are briefly discussed.     

Growth kinetic parameters of two planktonic desmid species under fluctuating phosphorus conditions in continuous-flow culture

Two planktonic desmid taxa, Staurastrum chaetoceras and Cosmariumabbreviatum var. planctonicum, were examined under pulsed phosphorus(P)-limited conditions in continuous culture. Two pulse regimeswere applied, i.e. 2.5 µM P twice a week and 10 µMP once every 2 weeks. Under both pulse regimes, S.chaetocerasshowed a higher maximum P uptake rate (V^max) and affinity forP uptake (V^max/affinity constant K^m) than C.abbreviatum. Affinityfor P uptake in S.chaetoceras just before pulsing was higherthan shortly after pulsing, whereas C.abbreviatum did not showany significant difference. Cell densities and cellular P quotain S.chaetoceras and C.abbreviatum fluctuated in a comparableway, but fluctuations in C.abbreviatum were less pronouncedthan in S.chaetoceras. The mean cell volume of both specieswas greater under the bimonthly than under the biweekly pulseregime, and the lowest under continuous P-limited conditions.Competition between S.chaetoceras and C.abbreviatum under thebimonthly pulse regime was won by S.chaetoceras, but displacementwas less fast than under more frequent pulsing (equalling thesame total P supply). The above-mentioned results are discussedin relation to possible ecological strategies.     

A review of European 'Mysella' species (Bivalvia, Montacutidae), with description of Kurtiella new genus

The type species of the genera Mysella Angas, 1877, RochefortiaVélain, 1878, Rochefortula Finlay, 1927 and AltenaeumSpaink, 1972 are illustrated and discussed. A new genus Kurtiellais introduced for ‘Mysella’ bidentata (Montagu,1803) and other European species currently placed in Mysella.These species display a unique diagnostic character state inhaving the cardinal platform deeply receding to house the internalligament, along with an array of more general montacutid traits.At the species level, diagnostic characters are given for thetype species K. bidentata, and for other included species K.ovata (Jeffreys, 1881), K. pellucida (Jeffreys, 1881), K. triangularis(Watson, 1897) and K. tumidula (Jeffreys, 1866), based mostlyon characters of the prodissoconch and on shell outline. Montacutasimillima Smith, 1892, from St Helena, is considered a juniorsynonym of K. pellucida. The loss of labial palps in K. tumidulais interpreted as a further derived character, which does notconflict with the generic placement in Kurtiella. (Received 28 August 2007; accepted 1 December 2007)     

Pollinator Specificity and Convergence in Fly-pollinated Pleurothallis(Orchidaceae) Species: A Multiple Population Approach

We studied the floral biology of 12 populations of five rupicolousPleurothallis(Orchidaceae) species occurring in campo rupestre vegetationat nine localities in Brazil. All of these species are pollinatedby flies belonging to the families Chloropidae and Phoridae.In the five Pleurothallis species studied, all conspecific populationsattracted the same pollinator species. All pollinators werefemales; they laid eggs in flowers of the two nectarless species,but never in the flowers of nectar-presenting species. The twopairs ofPleurothallis species with similar flower morphologiesand odours attracted the same pollinators: P. johannensis -P. fabiobarrosii, pollinated by Tricimba sp. (Chloropidae) andP. teres - P. ochreata pollinated by Megaselia spp. (Phoridae).There was no overlap in the distribution of thePleurothallisspecies that shared pollinators. Despite similarities in floralmorphology and odour, genetic data show that these species pairsare not each other's closest relatives. We hypothesize thatthese similarities are due to convergence in allopatric speciesthat evolved similar pollination mechanisms. Conversely, thereare reasons to believe that adaptation to different pollinationmechanisms occurred in the closely related species P. johannensisand P. teres.Copyright 2001 Annals of Botany Company Pleurothallis, Orchidaceae, floral biology, fly-pollination, Chloropidae, Phoridae, pollinator specificity, campo rupestre     

ANATOMY OF SOME PILL CLAMS (BIVALVIA: PISIDIOIDEA) FROM AFRICA, WITH THE DESCRIPTION OF NEW TAXA

The anatomy of 4 species of pisiid clam sampled in Ethiopia,Zimbabwe and South Africa was studied. The new species Pisidiumethiopicum is described, including the Ethiopian form regardedearlier as a variety of P. casertanum (Poli). P. incomitatumKuiper is included in the genus Musculium as type species ofa new subgenus Pseudopisidium. Anatomical characters of PisidiumkenianumPreston and P. langleyanum Melvill & Ponsonby arealso discussed. (Received 22 March 1994; accepted 23 August 1994)     

Sodium Accumulation in Pappophorum I. Uptake, Transport and Recirculation

The uptake, transport and accumulation of sodium were comparedin two grasses: Pappophorum pappifervm (Lam.) O. Kuntze, a glycophyteand P. philippianum L. R. Parodi, a facultative halophyte. Atlow salinity levels, (50 mM NaCl) shoots of salt-treated P.pappiferum accumulated lower Na⁺ concentrations than the otherspecies. This difference does not seem to be related to Na⁺uptake, as in short-time experiments (< I h), whole plantsof both species showed similar rates of Na⁺ uptake and transport Sodium recirculation was assessed in split-root experiments.It was similar in control (previously non-salinized) plantsof both species, but in salt-treated plants it was more significantin P. pappiferum. This mechanism, along with increased lossof recently acquired Na⁺, could contribute to keep Na⁺ levelslower in shoots of P. pappiferum than in P. philippianum. Pappophorum, Gramineae, sodium recirculation, salinity     

UV-B-induced damage and photoreactivation in three species of Boeckella (Copepoda, Calanoida)

Solar ultraviolet (UV) radiation poses a threat to most livingorganisms. Aquatic organisms have evolved three basic mechanismsto cope with harmful levels of radiation. Two mechanisms, avoidance(e.g. vertical migration) and photoprotection (e.g. productionof photoprotective compounds that act as filters, antioxidants,etc.), serve to minimize the dose of UV radiation that reachesthe organism's vital structures (DNA, membranes, etc.). Thethird mechanism, repair (e.g. dark repair mechanisms, such asnucleotide excision repair; or photoreactivation mechanisms,such as photoenzymatic repair), serves to repair the damagefollowing UV exposure. Here, we compare the vulnerability toUV-B radiation of three copepod species (Boeckella brevicaudata,Boeckella gibbosa, and Boeckella gracilipes) that occur in lakesthat differ in UV-B penetration and depth. Our aim was to gaininsight into the significance of each of the three mechanismsin different UV-B environments. Results from a 3-day ‘insitu’ incubation in ultra-oligotrophic Lake Toncek showedthat B.gracilipes is highly vulnerable to UV-B and UV-A radiation.In contrast, virtually no mortality was observed in B.gibbosaand B.brevicaudata during the same period. In order to discriminatethe contribution of photoprotection and photoreactivation, thethree species were subsequently exposed in the laboratory toan artificial source of UV-B radiation, both in the presenceand absence of visible radiation (recovery radiation). The photoprotectionpotential (i.e. resistance to UV-B in the absence of recoveryradiation) of B.gracilipes and B.gibbosa was lower than thatof B.brevicaudata. On the other hand, photoreactivation (higherresistance to UV-B in the presence of recovery radiation) wasobserved in B.brevicaudata and B.gibbosa, but not in B.gracilipes.To cope with damaging UV-B levels in nature, B.gracilipes dependsexclusively on the attenuation by the external media (i.e. avoidance).Although B.gibbosa tends to avoid the surface waters of lakes,it also occurs in shallow transparent pools. Most likely itsability to survive in these shallow, high UV environments isdue to its photoreactivation potential. Finally, despite itsoccurrence in highly turbid lakes, B.brevicaudata seems extremelywell suited to cope with UV-B radiation thanks to a combinationof photoreactivation and photoprotection.     

Predation risk and social interference as factors influencing habitat selection in two species of stream-dwelling waterstriders

We investigated how an aggressive species of waterstrider, Aquariusremigis, and potential predators, green sunfish (Lepomis cyanellus),affected the habitat use and mating behaviors of a less aggressivecongeneric species, A. conformis. Although these species sometimesco-occur, A. remigis typically lives in small streams with fewor no fish, whereas A. conformis are typically in medium- orlarge-sized streams with large populations of potentially predatoryfish. We tested in separate experiments in seminatural streams:1) the effect of fish on behaviors of A. conformis; 2) the effectof A. remigis on A. conformis; and 3) the habitat use of A.conformis when given a choice between pools with A. remigisor fish. The first experiment showed no effect of fish on eithermating behaviors or microhabitat use of A. conformis. This isin surprising contrast to the strong effects of fish alreadydocumented in A. remigis. The second experiment showed thatthe mating activity of A. conformis was reduced when A. remigiswere present; hence, A. conformis should avoid A. remigis. Finally,when A. conformis were presented with a choice between two pools,one containing A. remigis and the other containing fish, bothsingle males and pairs of A. conformis chose the pools withfish. In contrast, the habitat use of single female A. conformiswas not affected by either fish or A. remigis. Results fromthese experiments demonstrate that closely related species exhibitcontrasting social and antipredator behaviors and that aggressivesocial behavior is an important determinant of habitat partitioning     

中国萤火虫云南窗萤荧光素酶cDNA的克隆表达和序列分析(英文）

从一种来自中国日行性萤火虫（云南窗萤）发光器官mRNA中克隆、测序并表达了有功能的荧光素酶。云南窗萤荧光素酶的cDNA序列有1 647个碱基,编码548个氨基酸残基。从推测得到的氨基酸序列的比对分析得出：云南窗萤的荧光素酶与来自Lampyris noctiluca, L. turkestanicus和Nyctophila cf. caucasica三种萤火虫的荧光素酶有97.8%的序列一致性。从推测得出的氨基酸序列进行系统发育分析,其结果表明：云南窗萤和Lampyris+Nyctophila聚在一起, 与同属的发光强夜行性的萤火虫不形成的单系。云南窗萤荧光素酶在大肠杆菌中表达的条带大约70 kDa,并且在有荧光素存在时发出黄绿色荧光。对荧光素酶的结构模拟和分析表明,云南窗萤荧光素酶基因的氨基端和羧基端结构域之间的裂沟处存在这5个多肽环,这正是从其他荧光素酶推测得到的催化荧光反应时的底物结合位点。云南窗萤和窗萤属的其他3种萤火虫的荧光素酶相比,有13个不同氨基酸位点,位于模拟分子结构的表面。对于这些多肽环、不同氨基酸残基和晶体结构的进一步研究有利于解释日行和夜行性萤火虫荧光素酶的差异。