Invalidity of three Palaearctic species of Triaenophorus tapeworms (Cestoda: Pseudophyllidea): evidence from morphometric analysis of scolex hooks

A comparative study of the scolex hook morphology of five species of tapeworms of the genus Triaenophorus Rudolphi, 1793 (Cestoda: Pseudophyllidea), parasites of pikes (Esox lucius L. and E. reichertii Dybowski) in the Palaearctic Region, was carried out. Measurements of scolex hooks of 81 plerocercoids and 492 adults from different hosts and regions were compared using basic statistics and forward stepwise linear discriminant analysis. The shape of the scolex and that of tridental hooks were found to be suitable only for differentiation of the taxa with a similar shape of hooks, i.e. Triaenophorus nodulosus (Pallas, 1781) from T. amurensis Kuperman, 1968, and T. crassus Forel, 1868 from T. meridionalis Kuperman, 1968 and T. orientalis Kuperman, 1968, respectively. In contrast, discriminant analysis did not enable reliable separation of specimens of individual taxa of these two morphological groups due to high intraspecific variability and overlaps between species. This was reflected in low classification efficiencies (average 83%) of all species of the T. crassus group, whereas all T. amurensis specimens were misidentified as T. nodulosus. The new data also considerably enlarge (up to twofold) the size range of the species described by Kuperman in 1968, which invalidates suitability of the most important discriminant characteristic, the width of the basal plate, for delimitation of Triaenophorus species. Based on the present data, all Kuperman's taxa are considered to represent only distinct geographical populations of T. nodulosus and T. crassus. As a result, T. anmurensis is synonymized with T. nodulosus, whereas T. orientalis is considered to be a synonym of T. crassus. Previous synonymisation of T. ineridionalis with T. crassus, first proposed by Dubinina (1987), is also accepted.     

Flowers and fungi use scents to mimic each other

Some flowering plants mimic the scent and appearance of mushroom fruiting bodies. Fungi may also mimic flowers. In addition, infection of plants by certain fungi can direct the plant to develop nonfunctional floral-like structures that nonetheless primarily serve the reproductive advantage of the fungus. These various mimicries may serve to attract insects that in turn spread fungal spores or plant pollen, thus facilitating sexual reproduction of the cryptic organism.     

Growth and phenology variation in progeny of Scots pine seed orchards and commercial seed stands

Tree improvement in Poland has been most advanced for Scots pine, but existing seed orchards have not been progeny-tested yet. We examined variation in growth traits—tree height at ages 4 and 8 years, and diameter at age 13 years—in the common garden experiment testing open-pollinated progenies of 31 seed orchards and 5 commercial seed stands (referred to as populations) at 5 locations. We also examined bud burst phenology at two to five sites at three growing seasons. At one experimental site during the 5th growing season, we measured shoot growth rhythm on all populations. Similar measurements of shoot growth were done on a subset of populations during the 6th growing season together with the analysis of needle growth and foliar chemistry. We found significant variation among populations in growth traits, but also significant population × site (G × E) interactions. We used the regression approach and ecovalence analysis to examine populations’ performance stability. Most populations had average responsiveness to environment, and a set of least-responsive poor-growing populations contributed the most to the G × E interaction. Variation in bud burst phenology was associated with geographical distribution of tested progenies. The early bud-bursting populations originated from the north-eastern to north-central Poland, and a group of late bud-bursting populations originated mainly from the south-eastern region. Correlations between bud burst and growth traits were weak to medium and varied by site, but early bud-bursting populations tended to show stronger growth on height and diameter. We found significant differences among populations in final leader length, shoot elongation time and relative growth rate (RGR). However, RGR and shoot elongation time explained less than 30% of variation in leader length and were weakly correlated with tree height. Populations varied in needle length, specific leaf area and foliar nitrogen concentration, but time trends in these traits did not vary among populations or predefined groups of populations. Therefore, the analysis of growth rhythm or needle traits did not help resolve variation in tree growth to support selection decisions. Contrary to our expectation, progeny of seed orchards did not perform significantly better than that of commercial seed stands. This finding, however, should not be extrapolated beyond our set of populations. Nonetheless, the local seed sources were not always the best. From a selection standpoint, our results help culling the worst populations rather than selecting the best ones. Therefore, testing individual family progeny and genetic roguing of existing seed orchards is highly recommended.     

Dead-end (dnd) protein in fish—a review

Fish Physiology and Biochemistry - Dead end (dnd) is a germ plasm-specific maternal RNA discovered in zebrafish and then in other vertebrates. Dnd protein is essential for migration and motility of...     

Eradication of Rinderpest from Ethiopia

Tropical Animal Health and Production -     

Plant growth regulating properties of 1-amino-1-methylethylphosphonic acid and its derivatives

Seventeen derivatives of 1-amino-1-methylethylphosphonic acid were synthesised and evaluated for plant-growth-regulating activity using Cucumis sativus and Triticum aestivum. The tested compounds exerted either moderate herbicidal action or stimulated plant growth. The structure-activity relationships were similar to those observed earlier for the derivatives of 9-aminofluoren-9-ylphosphonic acids (phosphonic analogues of morphactins).     

The molecular biology and evolution of feline immunodeficiency viruses of cougars

Feline immunodeficiency virus (FIV) is a lentivirus that has been identified in many members of the family Felidae but domestic cats are the only FIV host in which infection results in disease. We studied FIVpco infection of cougars (Puma concolor) as a model for asymptomatic lentivirus infections to understand the mechanisms of host–virus coexistence. Several natural cougar populations were evaluated to determine if there are any consequences of FIVpco infection on cougar fecundity, survival, or susceptibility to other infections. We have sequenced full-length viral genomes and conducted a detailed analysis of viral molecular evolution on these sequences and on genome fragments of serially sampled animals to determine the evolutionary forces experienced by this virus in cougars. In addition, we have evaluated the molecular genetics of FIVpco in a new host, domestic cats, to determine the evolutionary consequences to a host-adapted virus associated with cross-species infection. Our results indicate that there are no significant differences in survival, fecundity or susceptibility to other infections between FIVpco-infected and uninfected cougars. The molecular evolution of FIVpco is characterized by a slower evolutionary rate and an absence of positive selection, but also by proviral and plasma viral loads comparable to those of epidemic lentiviruses such as HIV-1 or FIVfca. Evolutionary and recombination rates and selection profiles change significantly when FIVpco replicates in a new host.     

Disulfated Ophiuroid Type Steroids from the Far Eastern Starfish Pteraster marsippus and Their Cytotoxic Activity on the Models of 2D and 3D Cultures

New steroidal 3β,21-disulfates (2–4), steroidal 3β,22-disulfate (5), and the previously known related steroidal 3β,21-disulfate (1) were isolated from the ethanolic extract of the Far Eastern starfish Pteraster marsippus, collected off Urup Island in the Sea of Okhotsk. The structures of these compounds were determined by intensive NMR and HRESIMS techniques as well as by chemical transformations. Steroids 2 and 3 have an oxo-group in the tetracyclic nucleus at position C-7 and differ from each other by the presence of the 5(6)-double bond. The Δ²⁴-22-sulfoxycholestane side chain of the steroid 5 has not been found previously in the starfish or ophiuroid steroids. The cytotoxic activities of 1, 4, 5, and the mixture of 2 and 3 were determined on the models of 2D and 3D cultures of human epithelial kidney cells (HEK293), melanoma cells (SK-MEL-28), small intestine carcinoma cells (HuTu80), and breast carcinoma cells (ZR-75-1). The mixture of 2 and 3 revealed a significant inhibitory effect on the cell viability of human breast carcinoma ZR-75-1 cells, but other tested compounds were less effective.     

Redescription of Eubothrium fragile (Rudolphi, 1802) and E. rugosum (Batsch, 1786) (Cestoda: Pseudophyllidea), parasites of fish in the Holarctic Region

Two fish cestodes, the little-known Eubothrium fragile (Rudolphi, 1802) and E. rugosum (Batsch, 1786), the type species of the genus Eubothrium Nybelin, 1922, are redescribed on the basis of new material from twaite shad, Alosa fallax (Lacépède, 1803), from England and burbot, Lota lota (Linnaeus, 1758), from Russia, respectively. The tapeworms are compared with two other species of the genus, E. crassum (Bloch, 1779) and E. salvelini (Schrank, 1790), common parasites of salmonid fish in the Holarctic. The most notable differential characters are the size and the shape of the scolex (smaller and oval in E. fragile), the shape of the apical disc (four or more indentations in E. crassum), the number and size of the testes (the largest and least numerous in E. rugosum), and the position and size of the vitelline follicles (almost entirely cortical in distribution in E. fragile and E. crassum versus largely medullary in E. rugosum and E. salvelini). A comparison of species has also shown the morphological similarity of the freshwater species (E. rugosum and E. salvelini) on one hand and those of marine origin, E. fragile and E. crassum, on the other, with the latter species occurring also in fresh waters. A key to the identification of the species studied is also provided.