The status of Anostraca,Notostraca and Conchostraca (Crustacea: Branchiopoda) in Yugoslavia

The investigations of Anostraca, Notostraca and Conchostraca in Yugoslavia began after a great delay compared with other European countries. Intensive systematic investigations date back only to the 1970s.To date, 19 species have been recorded. All species, with the exception of Artemia salina, are faunal elements of the Pannonian region. Seven species, including Artemia salina, Branchinecta orientalis, Branchipus serbicus, Leptestheria dahalacensis, Limnadia lenticularis, Imnadia cristata and Imnadia panonica are known from single localities. Six species including Branchinecta ferox, Chirocephalus brevipalpis, Chirocephalus carnuntanus, Lepidurus apus, Eoleptestheria spinosa and Imnadia banatica have restricted distributions. Streptocephalus torvicornis and Cyzicus tetracerus are known from several localities, while Branchipus schaefferi, Chirocephalus diaphanus, Triops cancriformis and Leptestheria saetosaare common. Large branchiopods are mainly confined to anthropogenic landscapes, especially in the northern part of the country. Rare species inhabiting a single pond, or those with rather restricted distributions, are the most endangered and such species account for about 70% of the fauna. Limnadia lenticularis, Imnadia cristata and I. panonica have not been found for more than 20 years and they are probably extinct in Yugoslavia. Branchipus serbicus, Imnadia cristata and panonica have not been documented since being originally described. Eoleptestheria spinosa is currently the most endangered species since it only appears irregularly in small populations. At present, Branchinecta ferox, Chirocephalus carnuntanus and Imnadia banatica are the safest of the rare species as they regularly appear in large numbers. There are no large branchiopods on the List of protected animals in Yugoslavia. This revised version was published online in August 2006 with corrections to the Cover Date.     

The anostraca of the republic of Belarus

A survey of temporary freshwaters in the Republic of Belarus revealed the presence of two anostracan species (Chirocephalus josephinae and Drepanosurus hankoi). The two species co-occur in a majority of pools. Their life cycle partly overlaps, with D. hankoi the first to disappear. Morphological variability in Bielorussian populations is briefly discussed and compared with existing information. Two further species were found in Museum collections (Chirocephalus shadini and Streptocephalus torvicornis). This revised version was published online in July 2006 with corrections to the Cover Date.     

The large branchiopods (Anostraca,Notostraca and Spinicaudata) of Numidia (Algeria)

Between 1995 and 1999, we surveyed the large branchiopods (Crustacea, Branchiopoda) of Numidia, the coastal plain of northeastern Algeria. Samples from ca 100 sites yielded two species of Anostraca (Chirocephalus diaphanus, new to Numidia, and Tanymastix stagnalis), one notostracan (Lepidurus apus lubbocki) and one spinicaudatan (Cyzicus tetracerus). The absence of Streptocephalus torvicornis buchetiis noteworthy. An annotated check-list of all large branchiopods known from Algeria is also presented and discussed. Several species appear to be in danger of extinction.     

Intra- and interspecific variation in the chitin content of some anostracans

Chitin was assayed in adults of nine anostracan species (Streptocephalus dichotomus, S. proboscideus, S. simplex, S. torvicornis, Thamnocephalus platyurus, Dendrocephalus brasiliensis, Chirocephalus diaphanus, Artemia salina and Branchipus schaefferi) using a highly specific enzymatic method. Cysts of A. salina, T. platyurus and larvae of A. salina and S. simplex were also analysed for their chitin content. The results demonstrated a weak interspecific variation in chitin content among the adults. On the whole, it ranged from 9 to 33 mg chitin (g dry mass)⁻¹. In most species, the chitin level was not significantly different between males and females. In contrast, chitin levels varied significantly between cysts, larvae and adults within species. Comparison of the chitin content of anostracans revealed a comparable or lower chitin level than other crustaceans. This revised version was published online in August 2006 with corrections to the Cover Date.     

Anostraca of the Indian Subcontinent

There are 15 species of Anostraca belonging to 6 genera on the Indian Subcontinent. These are:Artemia sp. (reportedly a bisexual form of undetermined species);Artemia parthenogenetica Bowen & Sterling, 1978;Branchinecta orientalis Sars, 1901;Branchinella hardingi (Qadri & Baqai, 1956);Branchinella kugenumaensis (Ishikawa, 1895);Branchinella ornata Daday, 1910;Branchipodopsis acanthopenes (Malhotra & Duda, 1970);Branchipodopsis affinis Sars, 1901;Branchipus schaefferi Fischer, 1834;Chirocephalus priscus (Daday, 1910);Streptocephalus dichotomus Baird, 1860;Streptocephalus echinus Bond, 1934;Streptocephalus longimanus Bond, 1934;Streptocephalus simplex Gurney, 1906;Streptocephalus spinifer Gurney, 1906.Comparing numbers of species for southern India with other reasonably well studied areas, demonstrated that anostracan species richness is higher in the climatically more varied temperate regions than it is in the more uniform tropics. Tropical South India has six species compared to 13 in Arizona (USA), 19 in California (USA), 10 in Morocco, and 14 in Italy.     

Feeding strategy of two sympatric anostracan species (Crustacea)

The transport rate of chalk, clay particles and algal cells (Scenedesmus sp.) through the digestive tract of Streptocephalus torvicornis and Branchipus schaefferi is described under experimental conditions. Differences in transport rate as well as in the degree of digestion at a fixed particle density of algae were found. In S. torvicornis, the transport rate is higher and the digestion of algae lower than in B. schaefferi. These differences might reflect trophic differences related to niche partitioning in these sympatric species. This revised version was published online in August 2006 with corrections to the Cover Date.     

The filtration apparatus of Anostraca (Crustacea): species-specific setulation in the genus Streptocephalus

The structure of the setae, setules, spines and spinules on the limbs of males and females of Streptocephalus torvicornis, S. rubricaudatus and S. proboscideus are described, based on scanning electron micrographs. The data disclose significant variation among the three species in fine structure of the setules and inter-setular distance. The variation may be related to different trophic specialisations, facilitating the sympatric occurrence of congeneric species.     

An analysis of the setation pattern of the limbs in Anostraca (Crustacea); using the Algerian species as an example

The implantation, number, and structure of the state on th endopodites and exopodites of the limbs, and the setulation of the endite I of all Anostracan species found in Algeria are analysed by light and scanning electron microscopy and graphically represented. The data disclose segnificant variation among the generaArtemia, Branchinella, Branchipus, Chirocephalus, Streptocephalus andTanymastigites, and between the related congenersStreptocephalus torvicornis andS. rubricaudatus.     

On the occurrence of Streptocephalus torvicornis Waga 1842 (Crustacea,Anostraca) on a coastal island off Italy

The presence of Streptocephalus torvicornis on one coastal island off Italy (Cottarelli & Mura, 1995) is confirmed. Two years of sampling revealed an erratic pattern of occurrence, however, likely related to the unstable nature of the environmental characteristics. Such an unpredictability might be alternatively explained by a colonization-extinction process, or by adaptation to variations in annual weather (Donald, 1983). This revised version was published online in July 2006 with corrections to the Cover Date.     

Prevalence of strongyle nematodes in naturally infected ponies of different ages and during different seasons of the year in Louisiana

One hundred and seventeen ponies were surveyed for the seasonal prevalence of strongyloid parasites, particularly cyathostomes, and for host- and age-related differences in these infections. For 56 ponies, all stages of the cyathostome life cycle, both mucosal and luminal, were enumerated. Total numbers of cyathostomes and percentage of developing larvae (DL) encysted in the mucosa remained constant in all 4 seasons of the year, whereas a significant increase in the percentage of adults in the cyathostome population occurred in fall. In yearling ponies, encysted early third-stage larvae constituted a significantly lower percentage of the cyathostome population, and DL and adults formed a significantly higher percentage, compared with those stages in older ponies, 2-5 yr of age. More species of cyathostomes were present in yearling ponies than in older ponies. Significant differences occurred in fecal egg counts at different seasons of the year, even though adult cyathostome and large strongyle numbers remained constant. Twenty-four species of cyathostomes were found year-round, and 2 rare species were found in only 2 or 3 seasons of the year. Prevalences for these 24 species were not significantly different during any season, although 5 species had significant differences in intensity levels of infection in certain seasons of the year. Three species of large strongyle (strongylinae) adults had significant seasonal variations in intensities. These were Strongylus edentatus and S. vulgaris, which occurred in significantly higher numbers in summer and fall, and Triodontophorus brevicauda, which was more numerous in spring and summer. Fourth- and fifth-stage larvae of S. vulgaris recovered from the mesenteric vasculature were significantly more numerous in winter and spring than in other seasons.     

A contribution to the knowledge of the anostracan fauna of Iran

We report the finding of three anostracan species, Chirocephalus skorikowi Daday, 1913, Branchinecta orientalis Sars, 1901 and Branchinella spinosa. Milne-Edwards, 1840 in different localities in northwestern Iran. C. skorikowi was recorded in a lake at an elevation of 2400 m, whereas B. orientalis was found in a pond at 1280 m a.s.l. Co-existing B. spinosa and B. orientalis were collected in a pool close to the town of Tabriz, formerly indicated by Brehm (1954) as Estakr Chah, presently named EalGoli. Unlike Brehm (1954), we did not find Streptocephalus in the area of Tabriz.     

Seasonal variations in copepod size: effects of temperature, food abundance, and vertebrate predation

Seasonal dry weights of female and male Cyclops bicuspidatusthomasi, Diaptomus ashlandi and Diaptomus minutus were studiedin southeastern Lake Michigan during 1975–1981. Smallestanimals occurred during summer and early fall, and largest animalsin winter and spring, a pattern reported for other copepods.The range of weights for the species and sexes decreased fromwinter to summer, and converged in summer to a value of approximately2 µg/animal. Surface water temperature and abundancesof young-of-the-year (YOY) fish were inversely correlated withweights of males and females of the three copepod species. Standingstocks of important phytoplankton groups, especially pennatediatoms and flagellates, were positively correlated with copepodweight. Seasonal change of copepod body size appears to be morethan simply a function of temperature; seasonal predation byYOY fish may be a factor influencing sizes of adult copepods.     

Water quality of streams in the Great Smoky Mountains National Park

Water samples from streams in the Great Smoky Mountains National Park were analyzed for 16 physical, chemical, and bacteriological water quality parameters. Bacterial densities, pH, alkalinity, turbidity, and concentrations of Na, K, and Si were found to be higher in the low elevations than in the high. Nitrate concentrations increased with increasing elevation. Watersheds which had been logged prior to the establishment of the park had significantly lower stream water nitrate concentrations than unlogged watersheds at similar elevations. Bedrock geology was found to influence pH, alkalinity, conductivity, hardness, and concentrations of Na, K, Ca, Mg, and Si. The seasonal pattern for most water quality parameters was for higher concentrations or values in the summer and lower in the winter. Discharge was highest in the winter and spring and lowest in the summer and fall. Nitrate concentrations were highest in the late winter and early spring and lowest in the fall. Storm events often caused large changes in water quality.     

Seasonality of trichomycetes in larval black flies from South Carolina, USA

Trichomycete fungi are common endobionts of aquatic insect larvae, but little is known of their ecology. In this study, the seasonality of trichomycete colonization of larval black flies (Diptera: Simuliidae) was investigated in three streams in northwestern South Carolina. At least eight species of trichomycetes were found in two species of black flies, and 93.8% of 1819 larval black flies examined contained trichomycetes. Significant differences were found in the seasonal prevalence of Harpella melusinae, Simuliomyces microsporus, and Paramoebidium spp. at one of three sites. At this site, the lowest mean prevalence for H. melusinae occurred in winter (67%) versus the other seasons (96-100%), whereas mean prevalence was lowest in summer for Simuliomyces microsporus (1%) versus the other seasons (2-21%) and lowest in summer for P. spp. (9%) versus the other seasons (45-67%). Significant differences in levels of colonization among seasons were not detected. Conjugations of H. melusinae (representing early stages of sexual reproduction) occurred most frequently in the spring and winter (up to 14% of larvae). Sexual reproduction (represented by zygospores) of Legeriomycetaceae occurred most frequently in the spring and fall (up to 17% of larvae).     

Water relations,gas exchange,and growth of resprouts and mature plant shoots of Arbutus unedo L. and Quercus ilex L.

Resprout and mature plant shoot growth, leaf water status and gas exchange behavior, tissue nutrient content, flowering, and production were studied for co-occurring shallow-rooted (Arbutus unedo L.) and deeprooted (Quercus ilex L.) Mediterranean tree species at the Collserola Natural Park in Northeast Spain Resprouts showed higher growth rates than mature plant shoots. During fall, no differences in eco-physiological performance of leaves were found, but mobilization of carbohydrates from burls strongly stimulated growth of fall resprouts compared to spring resprouts, despite low exposed leaf area of the fall shoots. During summer drought, resprouts exhibited improved water status and carbon fixation compared to mature plant shoots. Shoot growth of Q. ilex was apparently extended due to deep rooting so that initial slower growth during spring and early summer as compared to A. unedo was compensated. Tissue nutrient contents varied only slightly and are postulated to be of minor importance in controlling rate of shoot growth, perhaps due to the relatively fertile soil of the site. Fall flowering appeared to inhibit fall shoot growth in A. unedo, but did not occur in Q. ilex. The results demonstrate that comparative examinations utilizing vegetation elements with differing morphological and physiological adaptations can be used to analyze relatively complex phenomena related to resprouting behavior. The studies provide an important multi-dimensional background framework for further studies of resprouting in the European Mediterranean region.     

Taphonomy and diagenesis in diatom assemblages; a Late Pleistocene palaeoecological study from Lake Magadi,Kenya

During these investigations the following species of Anostraca have been found: Chirocephalus diaphanus Prevost 1803, Chirocephalus brevipalpis (Orghidan, 1953), Streptocephalus torvicornis Waga 1892, Branchipus serbicus Marinek & Petrov 1988, Branchipus stagnalis L. (1758) and Branchipus sp. Thus, the total number of species discovered in Yugoslavia is 13.The shape of the frontal shield and the degree of flexure of the distal articles of antennae II in males are of no relevance to taxonomy in the genus Branchipus Schaeffer 1776. However, the apophyses on antennae II in males, shape of antennae II and of the ovisac in females, structure of eggs, and of appendages appear species-specific. We conclude that the differentiation of B. stagnalis into two forms (forma typica and forma visnyai) as well as the separation of B. visnyai Kertész 1956 as a distinct species are unfounded.     

Migration and Movement Patterns of Green Sturgeon (Acipenser medirostris) in the Klamath and Trinity rivers, California, USA

Green sturgeon, Acipenser medirostris, movement and migration within the Klamath and Trinity rivers were assessed using radio and sonic telemetry. Sexually mature green sturgeon were captured with gillnets in the spring, as adults migrated upstream to spawn. In total, 49 green sturgeon were tagged with radio and/or sonic telemetry tags and tracked manually or with receiver arrays from 2002 to 2004. Tagged individuals exhibited four movement patterns: upstream spawning migration, spring outmigration to the ocean, or summer holding, and outmigration after summer holding. Spawning migrations occurred from April to June, as adults moved from the ocean upstream to spawning sites. Approximately 18% of adults, those not out mignation in the spring, made spring post-spawning outmigrations. The majority of adults, those not outmigrating in the spring, remained in discrete locations characterized as deep, low velocity pools for extended periods during the summer and early fall. Fall outmigration occurred when fish left summer holding locations, traveled rapidly downstream, and exited the river system. High river discharge due to the onset of winter rainstorms and freshets appear to be the key environmental cue instigating the fall outmigration.     

Patterns and determinants of potential carbon gain in the C3 evergreen Yucca glauca (Liliaceae) in a C4 grassland

Yucca glauca is a C(3) evergreen rosette species locally common in the C(4)-dominated grasslands of the central Great Plains. Most congeners of Y. glauca are found in deserts, and Y. glauca's morphological similarities to desert species (steeply angled leaves, evergreen habit) may be critical to its success in grasslands. We hypothesized that the evergreen habit of Y. glauca, coupled with its ability to remain physiologically active at cool temperatures, would allow this species to gain a substantial portion of its annual carbon budget when the C(4) grasses are dormant. Leaf-level gas exchange was measured over an 18-mo period at Konza Prairie in northeast Kansas to assess the annual pattern of potential C gain. Two short-term experiments also were conducted in which nighttime temperatures were manipulated to assess the cold tolerance of this species. The annual pattern of C gain in Y. glauca was bimodal, with a spring productive period (maximum monthly photosynthetic rate = 21.1 ± 1.97 μmol·m·s) in March through June, a period of midseason photosynthetic depression, and a fall productive period in October (15.6 ± 1.25 μmol·m·s). The steeply angled leaves resulted in interception of photon flux density at levels above photosynthetic saturation throughout the year. Reduced photosynthetic rates in the summer may have been caused by low soil moisture, but temperature was strongly related (r = 0.37) to annual variations in photosynthesis, with nocturnal air temperatures below -5°C in the late fall and early spring, and high air temperatures (>32°C) in the summer, limiting gas exchange. Overall, 31% of the potential annual carbon gain in Y. glauca occurred outside the "frost-free" period (April-October) at Konza Prairie and 43% occurred when the dominant C(4) grasses were dormant. Future climates that include warmer minimum temperatures in the spring and fall may enhance the success of Y. glauca relative to the C(4) dominants in these grasslands.     

A lotic‐breeding salamander (Hynobius kimurae) modifies physiological and morphological traits during wintering

Unlike other migratory salamanders, Hynobius kimurae moves to aquatic hibernacula during fall. Does submergence into water during fall induce changes in physiological and morphological traits? We investigated whether such changes occur in both sexes from the entrance into the water (November) to the exit from the water (May) in the laboratory. Mean duration of stay in the water was 21.7 weeks in males and 19.0 weeks in females. Spermiation began 13.8 weeks after the males entered the water. Sperm storage lasted for 6.3 weeks. Spawning occurred 18.3 weeks after the females entered the water. Cloacae swelled greatly soon after the sexes entered the water. In males after entering the water, tail shape changed from sticklike to finlike. Although physiological and morphological traits in other species change simultaneously in both the submergence into water and the onset of breeding activity only during spring, such changes occurred in individual H. kimurae firstly during fall (shortly after entering the water) and secondly during spring (shortly after awaking from hibernation). This difference suggests that these two‐step changes during a prolonged period (fall–spring) are concentrated in a short period of aquatic‐breeding activity during spring in other species with terrestrial hibernation and associated reproductive cycles.     

Mortality in immatures of the floodwater mosquito Ochlerotatus albifasciatus (Diptera: Culicidae) and effects of parasitism by Strelkovimermis spiculatus (Nematoda: Mermithidae) in Buenos Aires Province,Argentina

Life tables were constructed for six cohorts of immature stages of the floodwater mosquito Ochlerotatus albifasciatus (Macquart) in a park in Buenos Aires, highlighting the mortality attributable to the parasitic nematode, Strelkovimermis spiculatus Poinar & Camino. Two cohorts were selected to compare parasite incidence in all mosquito stages when low and high parasitism occurred. Development time of Oc. albifasciatus from first instar to adult was 7.7-10 days in the spring, 6 days in the summer, and 10.9-21.9 days in the fall. Survival was estimated as 0-1.4% in the spring, 2% in the summer and 0.2-4.4% in the fall. The highest "K" value (Killing power) occurred during a fall cohort when prevalence of the parasite was 86.9%, and the lowest in a spring cohort. Parasitism occurred during all seasons, but S. spiculatus persisted to adult only in the summer and fall, when adult mosquitoes developed from parasitized third and fourth instars larvae. The abundance of S. spiculatus differed between old and young larvae only when parasite prevalence was the highest. Although pupae and adults of Oc. albifasciatus were parasitized, no pupal mortality attributable to parasitism was recorded. The proportion of parasitized adults ranged from 14.2% and 5.7% in the two cohorts compared. Pupal wet weight and adult wing lengths did not differ between parasitized and unparasitized individuals.