Seasonal occurrence of Lernaea cyprinacea on fishes in Belews Lake, North Carolina

Prevalence, abundance, and mean intensity of Lernaea cyprinacea were monitored on 3 species of fishes from June 1984 through August 1986 in Belews Lake, North Carolina. Copepods were observed parasitizing fishes only during summer, when water temperatures exceeded 25 C. Infection levels in mosquitofish (Gambusia affinis) and red shiners (Notropis lutrensis) were very low, but they were much higher in fathead minnows (Pimephales promelas). Infection levels do not appear to be related to the size of the host. Host differences in parasite prevalence may be due to the host habitats.     

Population dynamics of Lernaea cyprinacea (Crustacea: Copepoda) on four cyprinid species

A total of 217 Barbus graellsii, 54 Barbus haasi, 417 Cyprinus carpio and 85 Leuciscus cephalus captured at 9 sampling stations in the central basin of the Llobregat River (NE Spain) were studied for Lernaea cyprinacea parasitism. Prevalence (B. graellsii 39.2, B. haasi 31.5, C. carpio 8.4, L. cephalus 48.2), intensity of infection (B. graellsii range 1 to 39, mean 4.6; B. haasi range 1 to 7, mean 2.6; C. carpio range 1 to 16, mean 3.1; L. cephalus range 1 to 8, mean 2.4), and abundance (B. graellsii 1.80; B. haasi 0.83; C. carpio 0.26; L. cephalus 1.15) varied with the fish species studied. Correlations between abundance and host size were positive and significant for B. graellsii and L. cephalus. Correlation was positive but non-significant for B. haasi. Correlation between intensity and fish size was positive but not significant for B. graellsii, C. carpio, and L. cephalus. This is the first record of L. cyprinacea infecting B. graellsii and B. haasi.     

Effect of Lernaea cyprinacea (Crustacea: Copepoda) on stocked rainbow trout (Oncorhynchus mykiss)

Prevalence, intensity and pathogenesis of Lernaea cyprinacea (anchorworm) in stocked rainbow trout (Oncorhynchus mykiss) fingerlings were monitored annually for 4 yr (1981 to 1984) in East Canyon Reservoir, Utah (USA). Anchorworms were first detected in midsummer each year and were most abundant in the fall. The mean parasite intensity was highest in October 1982 (19 anchorworms per fish); in other years, maximum density was 7 to 9. The dorsal and caudal areas of the fish were the most heavily parasitized. The histological response to parasite attachment included an infectious granuloma similar to that reported in other fish hosts. Bacteria were not found in the kidneys of fish before stocking, but afterward bacteria that were presumptively identified as belonging to the genus Aeromonas, were found in the kidneys of up to 45% of the parasitized fish. Most (94%) anglers noticed the anchorworms, but few (8%) discarded parasitized fish. Some 28% used special cleaning techniques to prepare fish but 49% did nothing special to clean them. Lernaeosis probably had little effect on the fishery management goals for the reservoir.     

Lernaea cyprinacea (Copepoda: Lernaeidae) in the basin of the medial part of the Vychegda river

The Lernaea cyprinacea population distributed in the water basin of the medial part of the Vychegda river has one generation a year. It is probably the result of lower temperature of water during the year, than in south parts of L. cyprinacea range.     

Barbus comizo infestation by Lernaea cyprinacea (Crustacea: Copepoda) in the Guadiana River,southwestern Spain

The purposes of this study were to collect baseline data on parasitology of a native species and to determine if parasite infestations by Lernaea cyprinacea were related to size, month and sex. An infestation of L. cyprinacea was monitored on Barbus comizo (n = 307) from March to October 2004 in the River Guadiana, south‐western Iberian Peninsula; over 55.7% of the examined B. comizo were infested. The number of female parasites per fish ranged from 1 to 8. There were significant differences in prevalence, abundance, and intensity among months. Prevalence was highest in August, while abundance (5.16) and intensity (5.32) were highest in September. Infestation levels were significantly related to fish size (r_s = 0.947, n = 171, P < 0.05) and condition factor (r_s = ?0.199, n = 169, P < 0.05). Haematocrit values were significantly lower in infected fish (Mann–Whitney U = 21, P < 0.05). The level of infestation was independent of sex (χ² = 0.87, P < 0.05). The dorsal and ventral areas of the fish were the most heavily parasitized.     

A new egg-parasite of gipsy mothLymantria dispar (L.)

Summary Species ofScelionidae, parasiting in eggs ofLymantria dispar (L.) are mentioned and the results of use of these parasites are added. A new egg-parasite of gipsy moth —Hadronotus lymantriae n.sp. — is described. A key to Scelionid egg-parasites living inLymantria dispar (L.) is given. Attention is drawn to the fact thatH. bernardi Manev. is a nomen nudum. Finally, the author discusses the phylogenetical and taxonomical internal relations inHadronotus Foerst.

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Résumé L'auteur mentionne les différentes espèces de Scélionides parasites des œufs deLymantria dispar (L.) et rappelle les résultats obtenus par l'utilisation de ces parasites. Un nouveau parasite des œufs de ce Bombyx,Hadronotus lymantriae n. sp., est décrit. Il est montré en outre queH. bernardi Manev. doit être considérénomen nudum. Enfin l'auteur discute les relations phylogéniques et taxonomiques des espèces du genreHadronotus Foerst.

     

Lernaea cyprinacea (Copepoda, Lernaeidae) from crucian carp Carassius carassius from the Dlinnoje Lake in the middle stream of the Vychegda River

Till 1996 the Vychegda River's flood lakes at the territory of the biological station of the Syktyvkar University were overflowed every spring by water so that fishing took place from time to time. In 1996 a low flood level and intensive fishing resulted in the change of the infection rate of crucians by Lernaea, as well as in the change of the size and sex ratios of the crucian population in the Dlinnoje Lake. Thus, the size pattern of the crucian population became simpler, and it led to the changes in parasite-host relation. As a result, the intensity of the invasion of crucians by Lernaea cyprinacea have increased and the distribution of the parasite in the host population does not fit by the negative-binomial distribution. Crucian females and males play an equal role in the maintenance of the parasite population. In 1984 crucian females of medium and large body length played the main role in that process. Functions of other host groups (fishes of small body length, males) were different. Up to 2001 a significance of "k"-exponent of the negative-binomial distribution, describing the number of copepods in the mature part of crucian population, changed with a small range that suggests a stability of parasite-host relationship in the investigated crucian groups. We suppose that after a period of an unstable state in 1997-2000 the population of the parasite reached a new stable state.     

A new species of Lernaea L. (Copepoda: Cyclopoida) from Brazil,with notes on its ontogeny

A new species of Lernaea, closely related to L. cyprinacea, is described from both native and introduced fish species at a fish farming facility in Rio Grande do Sul, Brazil. All life-cycle stages of the new species, L. devastatrix, can be distinguished from L. cyprinacea by the reflexed claw on its antenna. A partial scheme of homologies of the antennulary segments is proposed, and the development of the segmentation and setation patterns is traced from CoIII to adults of both sexes. New interpretations are proposed of the homology of the antennary claw and of the maxillipedal endopod in lernaeids.     

A review of the occurrence of Grain softness protein-1 genes in wheat (Triticum aestivum L.)

Grain softness protein-1 (Gsp-1) is a small, 495-bp intronless gene found throughout the Triticeae tribe at the distal end of group 5 chromosomes. With the Puroindolines, it constitutes a key component of the Hardness locus. Gsp-1 likely plays little role in grain hardness, but has direct interest due to its utility in phylogeny and its role in arabinogalactan peptides. Further role(s) remain to be identified. In the polyploid wheats, Triticum aestivum and T. turgidum, the gene is present in a homoeologous series. Since its discovery, there have been conflicting reports and data as to the number of Gsp-1 genes and the level of sequence polymorphism. Little is known about allelic variation within a species. In the simplest model, a single Gsp-1 gene is present in each wheat and Aegilops tauschii genome. The present review critically re-examines the published and some unpublished data (sequence available in the NCBI nucleotide and MIPS Wheat Genome Databases). A number of testable hypotheses are identified, and include the level of polymorphism that may represent (and define) different Gsp-1 alleles, the existence of a fourth Gsp-1 gene, and the apparent, at times, high level of naturally-occurring or artifactual gene chimeras. In summary, the present data provide firm evidence for at most, three Gsp-1 genes in wheat, although there are numerous data that suggest a more complex model.     

A new repetitive DNA sequence family in the olive (Olea europaea L.)

Two families of repeated DNA sequences were cloned from Olea europaea ssp sativa cv. "Picual". The first repetitive DNA is organized in a tandem repeat of monomers of 178 bp. Sequencing of several clones showed that it is relatively A-T rich (54.49%) and possesses short direct and inverted subrepeats as well as some palindromic sequences. Comparison between the monomers revealed heterogeneity of the sequence primary structure. This repetitive DNA is present in several cultivars of olive cultivates. Comparison of sequences with other repetitive DNAs described in Olea europaea has been carried out. No significant similarity was found. All the obtained results suggest that this repetitive DNA described here is a new family of repetitive DNA. The second repetitive DNA is organized in a tandem repeat of monomers of 78 bp. This second family of repetitive DNA showed significant similarity with other repetitive DNAs previously described in Olea europaea. Their existence in new cultivars of olive is shown.     

Using satellite data to forecast the occurrence of the common tick Ixodes ricinus (L.)

To forecast the incidence of the common tick, Ixodes ricinus, the authors used the finding that some types of vegetation may indicate the presence of the tick. To obtain the necessary information in a scope which would enable its practical application in medicine to prevent populational exposure to ticks, remote sensing data were utilized as obtained from the Multispectral Scanner operating aboard Landsat 5. A file was selected from the full scene representing a territory which measured 41 by 41 kilometers and in the centre of which there was an area known to have consistently high tick numbers, as revealed in a 25-year continuous study of I. ricinus, and which proved to be a natural focus of tick-borne encephalitis. This area (Potepl) was taken as a model and was compared with its surroundings. Six landscape classes were examined (1--coniferous forest, 2--leaved forest, 3--mixed forest, 4--water basins, 5--glades, 6--housing developments), the former three being of crucial importance to evaluate the probability of tick presence. The 6th category is significant in assessing human exposure to ticks. Data processing was carried out by supervised classification using the Baye's decision rule of maximum likelihood. The findings were obtained both in a graphic form and in the form of statistical reviews as regards the presence of appropriate landscape categories.     

A note recording the occurrence of hermaphroditic smelt, Osmerus eperlanus (L.) from the river Thames, England

Of a sample of 703 smelt, Osmerus eperlunus , from the estuary of the river Thames, 2.6% were identified as being synchronous hermaphrodites. The fish are compared with previously reported hermaphroditic smelt.     

A new glycosylated dihydrophaseic acid from cacao germs (Theobroma cacao L.)

Cacao beans are composed of cacao nibs and germs. Although numerous chemical and physiological studies on cacao nib compounds have been reported, there is little information on cacao germ compounds. We therefore analyzed an extract from the cacao germ, and found two compounds that were specific to the germ. One of these two compounds was identified as the new glycosylated abscisic acid metabolite, dihydrophaseic acid-4'-O-6″-(β-ribofuranosyl)-β-glucopyranoside, and the other as the known compound, dihydrophaseic acid-4'-O-β-D-glucopyranoside.     

A presumed new photoreceptor in copepod crustaceans

Summary A new photoreceptor in the Copepoda is described. The organ, previously called Gicklhorn's organ (Elofsson, 1966a), is paired and is usually situated beneath the cuticle of the front. Each member of the pair consists of two cells. From the anterolateral position, two nerves lead to the lateral part of the brain. No connexion with the nauplius eye is found. Each cell of the organ has microvilli, two nuclei, dictyosomes, and large cisternae of the endoplasmic reticulum. Except for the binucleated condition, the cells closely resemble the retinula cells of the copepod nauplius eye.It is concluded that, because of its independent position, the new photoreceptor is not a detached part of the nauplius eye. As there are no accessory structures present and no missing links so far known, it is doubtful whether it can be regarded as a vestigial compound eye. The most plausible hypothesis is that the new presumed photoreceptor is an independent structure without connexions either with crustacean compound or nauplius eyes.If the function of the nauplius eye is considered by itself the improvement contributed by the new organ is probably modest because of its low level of organization. Some experimental evidence on light reception in Copepods points to a possible function in response to directed light.This work was supported by a grant from the Swedish Natural Science Research Council 2760-3.     

Complex interspecific hybridization in barley (Hordeum vulgare L.) and the possible occurrence of apomixis

Summary Several complex hybrids were produced from the combination [(Hordeum lechleri, 6x xH. procerum, 6 x) × H. vulgare, 2 x]. Crosses with six diploid barley lines resulted in triple hybrids, most of which had a full complement of barley chromosomes (no. 1–7), but were mixoploid with respect to alien chromosomes (19–22). In one combination, chromosome no. 7 was duplicated. Meiosis in triple hybrids showed low, but variable pairing (1.3–5.5 chiasmata per cell). The syndesis probably did not include the barley chromosomes. Direct back-crosses to di- and tetraploid barley lines were unsuccessful. Chromosome doubling of the triple hybrid based on cv Pallas resulted in a plant with 2n = 53–56, which had an increased fertility. Backcrosses to one di- and one tetraploid barley line resulted in offspring. The cross made with the tetraploid line (Haisa II), produced a 28-chromosomic plant in which the male parental genome was absent. We suspect that this plant may have arisen through parthenogenetic development of a reduced female gamete. The other cross with a diploid line (9208/9) resulted in plant with 2n = 51–53. The most likely explanation for this second plant is that an unreduced gamete from the amphiploid was fertilized by a normal gamete from the backcross parent, and during early embryo development, some chromosomes were eliminated.     

A new subspecies of the vernal bee,Colletes cunicularius (L.) (Hymenoptera: Colletidae)

An account is given of the British populations of Colletes cunicularius (L.) which are recognised as subspecifically distinct on morphological and biological grounds. The distribution and history in Britain of the new subspecies is discussed.     

The occurrence and abundance of helminth parasites of the mountain hare Lepus timidus (L.) and the wild rabbit Oryctolagus cuniculus (L.) in Aberdeenshire, Scotland

Mountain hares were collected each month between April 1984 and March 1985 and their intestines examined for helminths. 26 rabbits were also collected between July and December 1984 and examined for gastro-intestinal helminths. Three nematode and two cestode species were found in the hares while only two nematode and one cestode species were found in the rabbits. Trichostrongylus retortaeformis was recorded from 88% of the 193 hares and 92% of the rabbits while comparable figures for Passalurus ambiguus were 0.5% and 54% and for Mosgovoyia pectinata 14% and 81%. Seasonal fluctuations were observed in the T. retortaeformis populations in the hare; numbers tended to be low during the winter months and high throughout the summer. Paranoplocephala wimerosa was reported for the first time from the British Isles and Trichostrongylus axei was recorded for the first time in the mountain hare.     

Effect of the infestation by Lernaea cyprinacea Linnaeus, 1758 (Copepoda, Lernaeidae) on the leucocytes of Schizodon intermedius Garavello & Britski, 1990 (Osteichthyes, Anostomidae)

Differential white blood cell counts from Schizodon intermedius infested by Lernaea cyprinacea were carried out and compared using the Wilcoxon matched pairs test. The observations were performed in fish infested by 16-77 adult Lernaea, fish with parasitic lesions but without attached crustaceans, and non parasitized fish (control group). The specimens of Schizodon intermedius were obtained from the University of Londrina fish farming facilities. The following leucocytes were observed: lymphocytes, neutrophils, monocytes, basophils, eosinophils and immature leucocytes. Intense lymphocytopenia and neutrophilia were observed in the infested hosts. Consistent increasing of monocyte percentage values occurred in the infested fish. The highest values for immature leucocytes counts were recorded from infested fish specimens.