Arctodiaptomus (Rhabdodiaptomus) michaeli n.sp. (Copepoda,Calanoida) from Kashmir,India

Arctodiaptomus (Rhabdodiaptomus) michaeli n.sp. is described from the material collected in Alapathar Lake and Marsar Lake of Kashmir, India.     

Phytoplankton diet of Arctodiaptomus salinus (Copepoda, Calanoida) in Lake Shira (Khakasia)

A flow-through method was employed to study the algal part of the diet spectrum of the calanoid Arctodiaptomus salinus in the surface layer of the lake and in the phytoplankton biomass maximum zone (10 m deep). Daily consumption rates of this calanoid differed markedly in these layers, being 1 and 11 g ind ^–1 d^–1, respectively. The cyanobacterial taxa, Lyngbya contorta and Microcystis sp., accounted for more than a half of the ration. Nevertheless, the negative Ivlev electivity coefficient indicated that Arctodiaptomus prefers none of these two taxa. The low measured uptakes suggest that the energy expenditure is compensated by other resources, presumably microzooplankton and detritus.     

The extinction of Arctodiaptomus alpinus (Copepoda) following the introduction of charr into a small alpine lake Dvojno Jezero (NW Slovenia)

In 1991 about twenty-five age 2+ specimens of the Arctic charr (Salvelinus alpinus (L.) (length between 100 and 130 mm) were introduced into the fishless small mountain lake Dvojno Jezero (= Twin Lake) (area 0.5+0.4 ha; max. depth 8 m, altitude 1670 m) in NW Slovenia. The first spawning of the Arctic charr was observed in autumn 1994 and regularly each year thereafter. Fish of different sizes were observed from 1995 onward each year but a fish census was never carried out. Autumn zooplankton samples, collected before the introduction of Arctic charr, contained adults (including ovigerous females) of two copepod species: Cyclops abyssorum tatricus and Arctodiaptomus alpinus. No planktonic Cladocera were found. Seven years after the introduction of fish standing crop of zooplankton declined 100-fold. The zooplankton contained only a few copepodites (IV and V) of C. a. tatricus. Simultaneously, water transparency declined and the concentration of chlorophyll a increased and filamentous green algae and picoplankton became abundant in the littoral zone of both lakes.     

Zur Kenntnis von Morphologie und Systematik einiger Arten der Gattung Arctodiaptomus Kiefer (Crustacea, Copepoda)

In the present study the author continues the revision of several species of the genus Arctodiaptomus Kiefer. Based on a detailed morphological comparison of animals from 34 different localities the species Arctodiaptomus similis (Baird), A. dudichi Kiefer, A. stephanidesi (Pesta) and A. byzantinus Mann are redescribed. Arctodiaptomus osmanus is characterized as a new species. For A. similis a list of synonyms is given. The centre of distribution of this interesting diaptomid seems to be in Israel, Lebanon and Jordan. Some populations are known also from Iran, Anatolia and Bulgaria. A. byzantinus is found not only in SE-Europe but recently also in the peninsula of Krim. Finally, there are only two habitats known of A. osmanus , both situated in 2 000 m above sea-level in NW Turkey and in Armenia.

Zusammenfassung

Verfasser setzt in der vorliegenden Studie seine Revisionsarbeit an mehreren Arten der Gattung Arctodiaptomus Kiefer fort. Arctodiuptomus similis (Baird), A. dudichi Kiefer, A. stephanidesi (Pesta) und A. byzantinus Mann werden auf Grund neuer vergleichend-morphologischer Untersuchungen eingehend gekennzeichnet und A. osmanus als neue Spezies in die Wissenschaft eingefuhrt. Fur A. similis wird eine Liste von Synonymen rusammengestellt. Der Schwerpunkt der Verbreitung dieses interessanten Diaptomiden scheint in den Landern des ostlichen Mittelmeers zu liegen, namlich in Israel, Libanon und Jordanien. Einzelne Funde stammen auBerdem aus Iran, Zentral- und West-Anatolien sowie aus Bulgarien. A. byrantinus ist nicht nur in Siidosteuropa verbreitet, sondern konnte nunmehr auch fur die Halbinsel Krim nachgewiesen werden. A. osmanusschlieDlich ist vorerst nur aus zwei 2000 m hoch gelegenen Seen in Nordwest-Anatolien und in Armenien bekannt.     

The effect of chemicals released by Gammarus lacustris on the depth distribution of Arctodiaptomus salinus in laboratory conditions

The effect of treatment water containing chemicals released by Gammarus lacustris or crushed/injured Arctodiaptomus salinus induced changes in vertical distribution of Arctodiaptomus in laboratory conditions. With food concentration in the medium corresponding to the maximum of algae concentration in Shira lake, A. salinus in an experimental vessel was situated higher than in the control. Average population depth of A. salinus decreased as the inoculation density of G. lacustris increased.     

Naupliar development of Acanthodiaptomus denticornis (wierzejski, 1887) and Arctodiaptomus alpinus (Imhof, 1885) (Copepoda: Calanoida) and a comparison with other Diaptomidae

The six naupliar instars of the two alpine species Aconthodiaptornusdenticornis and Arctodiaptomus alpinus are described and illustrated.Their external morphology is compared with that of all presentlyknown diaptomid nauplii in an attempt to provide usehl taxonomiccharacteristics to identify larval diaptomids. The larval stagesof the two species are remarkably similar in size and overallappearance, and show an identical pattern of limb setation throughoutthe whole development. Diagnostic characters are mainly relatedto the differentiation of antennules and caudal armature.     

Post-embryonic developmental plasticity of Arctodiaptomus salinus (Copepoda: Calanoida) at different temperatures

Ephemeral and semi-permanent saline wetlands undergo frequentunpredictable disturbances such as episodes of high salinityor desiccation. Organisms living in these systems are adaptedto survive and develop in very fluctuating and unpredictableconditions and, therefore, could help us to understand lifecycle strategies and plasticity in the context of global warming.Arctodiaptomus salinus is a common species occurring in suchenvironments and is often the main constituent of their zooplanktoncommunity, which is characterized by low diversity and shorttrophic webs. Despite the qualitative and quantitative importanceof A. salinus in these systems, no attention has been paid tothe effect of temperature on its population dynamics. For thisreason, variability in post-embryonic development times andstage-specific mortality of A. salinus were studied for thetemperature-range over which this species occurs. Mortalitywas higher in earlier naupliar and first copepodite stages.The highest developmental variability and mortality occurredat the highest temperature. Developmental instability couldexplain the high variability at high temperatures and the fluctuatingspeed of development throughout the successive stages. The interactionbetween mortality and developmental variability might be animportant mechanism ensuring persistence of A. salinus populationsin these fluctuating and stressing environments.     

The annual cycle and production of Arctodiaptomus laticeps (Sars) in Lake Malsjoen, Norway

The annual cycle and production of Arctodiaptomus laticeps (Sars)was studied in the small Lake MålsjÖen, the waterof which is characterized by CaO 11 mg/l, pH 7.0, and much humus.Reproduction takes place at the turn of February-March. Thenauplii stay in the water until the ice breaks, in mid-May.Thereafter the metamorphosis takes place very rapidly and CIV reach their maximum in mid-June. The C V stay in the wateruntil late September, when adults suddenly occur. The adultslive under the ice during winter, the mortality being almostzero until the first egg-bearing females occur in late February.Three successive generations had identical cycles. Less than10% of a generation's production was eggs and nauplii, 50% establishedthe biomass of C IV in June, the rest of the production maintainedthe biomass in July-October. The yearly production was 550 mgm^–2 dry weight in 1970 and 340 in 1971, establishing amean biomass of 226 and 119 mg m^–2 for the productiveperiod 25 May-5 October.     

Alpine newts (Triturus alpestris) as top predators in a high-altitude karst lake: daily food consumption and impact on the copepod Arctodiaptomus alpinus

1. Population dynamics and feeding ecology of adult and larval alpine newts (Triturus alpestris, Laurenti) were investigated in a high-altitude karts lake to estimate their feeding pressure on the copepod Arctodiaptomus alpinuf (Imhof). Estimates of population size for reproducing adults ranged from 666 to 864 individuals in the lake during July and August. Total abundance of larvae before the onset of ice cover varied considerably between 4400 and 25400 individuals in different years. 2. Arctodiaptomus alpinus was an important prey item for adult and larval alpine newts. During the second half of their aquatic period, adult newts moved to deeper water where the copepod reached its highest densities near the sediment. Adults and larvae exhibited no periodic feeding pattern. The feeding rhythm was more synchronized among the larvae than among the adults. 3. Daily food consumption, estimated using the Elliott & Persson (1978) model, reached 4–21 mg dry biomass in adults. The daily ration of larvae was about 7% of body dry weight in the temperature range 6-11°C. Compared to published estimates of daily food consumption in salmonid fishes, the feeding pressure of newts appears low.     

Factors determining the average body size of geographically separated Arctodiaptomus salinus(Daday,1885) populations

Arctodiaptomus salinus inhabits water bodies across Eurasia and North Africa.Based on our own data and that from the literature,we analyzed the influences of several factors on the intra-and inter-population variability of this species.A strong negative linear correlation between temperature and average body size in the Crimean and African populations was found,in which the parameters might be influenced by salinity.Meanwhile,a significant negative correlation between female body size and the altitude of habitats was found by comparing body size in populations from different regions.Individuals from environments with highly varying abiotic parameters,e.g.temporary reservoirs,had a larger body size than individuals from permanent water bodies.The changes in average body mass in populations were at 11.4 times,whereas,those in individual metabolic activities were at 6.2 times.Moreover,two size groups of A.salinus in the Crimean and the Siberian lakes were observed.The ratio of female length to male length fluctuated between 1.02 and 1.30.The average size of A.salinus in populations and its variations were determined by both genetic and environmental factors.However,the parities of these factors were unequal in either spatial or temporal scales.     

Selective feeding of Arctodiaptomus salinus (Copepoda, Calanoida) on co-occurring sibling rotifer species

1. Using two‐ and three‐dimensional video recordings, we examined the steps involved in predation that lead to the differential vulnerability of three sympatric rotifer sibling species (Brachionus plicatilis, B. ibericus and B. rotundiformis) to a co‐occurring, predatory, calanoid copepod (Arctodiaptomus salinus). 2. Brachionus rotundiformis, the smallest prey tested, was the most vulnerable with the highest encounter rate, probability of attack, capture and ingestion, and the lowest handling time. 3. Comparison of our results with those of a previous study shows that A. salinus is a more efficient predator than a co‐occurring cyclopoid copepod (Diacyclops bicuspidatus odessanus) feeding on these same rotifer species. However, despite its higher capture rates, A. salinus seems to be less selective than D. b. odessanus based on attack distances and prey handling times. 4. The differential vulnerability to both calanoid and cyclopoid copepod predation can help explain the coexistence and seasonal succession of these co‐occurring rotifer species.     

Synopsis ofVerbesina sect.Ochractinia (Asteraceae)

A taxonomic revision ofVerbesina sect.Ochractinia is presented. 40 species plus 7 additional infraspecific taxa are recognized. A table of the distribution of the species, key to the species and synonymy are included. Relationships to other sections ofVerbesina and species relationships within sect.Ochractinia are discussed.     

Sero-systematics ofCytisus sect.Trianthocytisus (Fabaceae)

The serological reaction of seed proteins provides evidence for a partly new systematic arrangement ofCytisus sect.Trianthocytisus and ofCytisus s.l. Proposed modifications agree with recent advances in morphological taxonomy. Sect.Trianthocytisus includes only two species,C. villosus andC. aeolicus. Its position is central within the genus, and this fact agrees with the proposed retypification ofCytisus (type species:C. villosus).C. emeriflorus, formerly included in the same section, constitutes the monospecific sect.Emeroides, which is intermediate towards the genusLembotropis. This is serologically isolated and includes onlyL. nigricans. It is confirmed thatC. sessilifolius should be removed from the genusCytisus as a monospecific genus:Cytisophyllum Lang which is closely allied toHesperolaburnum and toPodocytisus, the most primitive genera ofGenisteae.     

Diaptomidae (copepoda,calanoida) of Israel and Northern Sinai

A study on the morphology, biology, distribution and habitat characteristics of inland water diaptomids of Israel and Northern Sinai is presented. Taxonomic status, seasonal colour change and adaptations of these species for living in temporary waters are discussed. Two new subspecies are established, namely Arctodiaptomus (Arctodiaptomus) similis irregularis n.ssp and Hemidiaptomus (Hemidiaptomus) gurneyi canaanita n.ssp.     

New species ofBeaufortia andChamaelaucium (Myrtaceae),Drosera (Droseraceae) andPultenaea (Fabaceae) from SW. Australia

Four new species of the generaBeaufortia, Chamaelaucium, Drosera, andPultenaea are described based on the author's collections from SW. Australia. Their affinities are discussed and full illustrations are provided.Dedicated to Hofrat Univ.-Prof.K. H. Rechinger on the occasion of his 80th birthday.     

Infection of Glaucocystis nostochinearum (Glaucophyta) by Lagenidium sp. (Oomycota) and its hyperparasite Pythiella sp. (Oomycota)

The glaucophyte Glaucocystis nostochinearum has to our knowledge been observed to be infected by a parasite for the first time. It was found in samples taken from the northernmost freshwater pond in Germany (on the island of Sylt). The fungal parasite was identified as the oomycete Lagenidium sp. which itself was parasitised by another oomycete, Pythiella sp.     

Genome size in Bulgarian Centaurea s.l. (Asteraceae)

Thirty-nine species and subspecies of the genera Centaurea, Colymbada, Psephellus and Cyanus (all included in Centaurea s.l.) including many rare and endemic taxa of preponderantly Bulgarian distribution have been investigated with Feulgen DNA image densitometry for holoploid and monoploid genome size (C- and Cx-values). Cyanus varies gradually 2.17-fold between 0.74 pg and 1.56 pg (1Cx). In the remaining taxa two major genome size groups are found, which differ about 1.8-fold in Cx-value. Low values occur in Centaurea subgenera Acrolophus, Solstitiaria, Phalolepis (0.77 pg to 0.90 pg, 1Cx) and Jacea (0.95 pg to 1.09 pg, 1Cx), high values in the genera Colymbada (1.65 pg to 1.93 pg, 1Cx) and Psephellus (1.79 pg, 1Cx, in P. marschallianus). Cx-values support a distinction of Colymbada from Centaurea. Genome size variation is discussed with regard to phylogeny, life form (annual versus perennial), polyploidy, chromosome basic numbers, altitude of occurrence and climate, endemism, and rarity.     

ThechlL (frxC) gene: Phylogenetic distribution in vascular plants and DNA sequence fromPolystichum acrostichoides (Pteridophyta) andSynechococcus sp. 7002 (Cyanobacteria)

We examinedchlL (frxC) gene evolution using several approaches. Sequences from the chloroplast genome of the fernPolystichum acrostichoides and from the cyanobacteriumSynechococcus sp. 7002 were determined and found to be highly conserved. A complete physical map of the fern chloroplast genome and partial maps of other vascular plant taxa show thatchlL is located primarily in the small single copy region as inMarchantia polymorpha. A survey of a wide variety of non-angiospermous vascular plant DNAs shows thatchlL is widely distributed but has been lost in the pteridophytePsilotum and (presumably independently) within the Gnetalean gymnosperms.The namefrxC was originally used to denote a gene encoding a product with probable Fe : S cluster binding activity. This activity was postulated due to the amino acid sequence similarity between this product and the Fe : S-binding nitrogenase iron proteinnifH. Fe : S-binding is a property shared by ferredoxins, which are denoted by the prefix frx. However, this gene does not encode a ferredoxin. It is much larger than any known ferredoxin, it binds its Fe : S cluster between two halves of a homodimer (Fujita & al. 1989,Burke & al. 1993 a, c) instead of within a single subunit, and it lacks the pattern of clustered cysteines present in all ferredoxins (Meyer 1988). Therefore, we use the namechlL to recognize the sequence and functional similarities to the bacterial PChlide reductase subunit,bchL. Similar usage has been adopted for this (Suzuki & Bauer 1992) and other (Choquet & al. 1992,Burke & al. 1993b) PChlide reductase subunits.     

Cytotaxonomical study ofSaxifraga seriesCeratophyllae s.l. (Saxifragaceae)

Chromosome numbers, mainly gametic, are given for 28 populations belonging to 13 species in ser.Ceratophyllae as circumscribed byWebb & Gornall. From a cytological point of view, we report or confirm the occurrence of aneuploidy in at least 8 of the 19 species recognized. This phenomenon, together with the technical difficulties inherent to the genus, is responsible for a number of incorrect or imprecise previous reports which are here questioned. Aneuploidy and the karyological instability behind it apparently reflect very active extant processes which might play an important role in the evolution of the group. Cytological and morphological data allow the recognition of four groups; one of them is likely to constitute a monophylectic group (ser.Ceratophyllae sensu stricto) but, the monophyly of the seriesCeratophyllae sensu lato is questioned.     

Hair anatomy inPlantago subg.Psyllium (Plantaginaceae)

The hairs of seven representatives ofPlantago L. subg.Psyllium were studied. Three types of headless hairs and three types of headed hairs were observed. Clavate hairs and hairs with several-celled stalk and unicellular head are characteristic of subg.Psyllium and provide evidence for the distinctness of this taxon. Based on our studies it can be assumed thatRahn's idea of enlarging subg.Psyllium by six sections from subg.Plantago sensuPilger is incorrect.