The external morphology of Aphylidae was studied previously in detail by the two junior authors, including the description of unique derived structures formed by their lateral thoracico-abdominal region (the exponium). Here we provide an additional description of the external scent efferent system of the metathoracic scent glands of species in the genus Aphylum Bergroth, 1906 (based on scanning electron microscope study) and its connection with an autapomorphic aphylid thoracico-abdominal region, the exponium. The origins of exponial sclerites are discussed and function of the exponium is hypothesised as being part of a complex defensive mechanism in the Aphylidae., Petr Kment, Pavel Štys, Jitka Vilímová., and Obsahuje seznam literatury
a1_Three genera of rhinebothriideans, previously referred to as New genus 1, New genus 2 and New genus 4, are erected in the the Anthocephaliidae. New genus 1 is established as Divaricobothrium gen. n., with Divaricobothrium tribelum sp. n. as its type species; Echeneibothrium trifidum Shipley et Hornell, 1906 is transferred to the genus as Divaricobothrium trifidum (Shipley et Hornell, 1906) comb. n. This genus is unique among rhinebothriidean genera in bearing bothridia that are posteriorly deeply divided into two lobes with facial loculi but no apical sucker, and a vagina that extends to near the anterior margin of the proglottid. Its species parasitise Indo-Pacific members of the genera Brevitrygon Last, Naylor et Manjaji-Matsumoto, Maculabatis Last, Naylor et Manjaji-Matsumoto and Pateobatis Last, Naylor et Manjaji-Matsumoto. New genus 2 is established as Barbeaucestus gen. n., with Barbeaucestus jockuschae sp. n. as its type species; Barbeaucestus ralickiae sp. n. is also described. Anthobothrium sexorchidum Williams, 1964 and Rhinebothrium shipleyi Southwell, 1912 are transferred to the genus as Barbeaucestus sexorchidus (Williams, 1964) comb. n. and Barbeaucestus shipleyi (Southwell, 1912) comb. n., respectively. This genus is unique among rhinebothriidean genera in that its bothridia are substantially wider than long, bear an apical sucker and at least one row of two or more facial loculi in their anterior half. Its species parasitise the genera Neotrygon Castelnau and Taeniura Müller et Henle. New genus 4 is established as Sungaicestus gen. n. with transfer of Rhinebothrium kinabatanganensis Healy, 2006, as Sungaicestus kinabatanganensis (Healy, 2006) comb. n., as its type species. Among the genera of its order, this genus most closely resembles Rhinebothrium Linton, 1890, however, despite the original description, the bothridia were found to bear, rather than lack, apical suckers., a2_This monotypic genus is known only from the freshwater stingray Urogymnus polylepis (Müller et Henle). The familial diagnosis of the Anthocephaliidae Ruhnke, Caira et Cox, 2015 is emended. The family now houses five genera., Janine N. Caira, Claire J. Healy, Fernando P.L. Marques, Kirsten Jensen., and Obsahuje bibliografii
a1_Three new species of acanthocephalans are described from marine fishes collected in Sodwana Bay, South Africa: Rhadinorhynchus gerberi n. sp. from Trachinotus botla (Shaw), Pararhadinorhynchus sodwanensis n. sp. from Pomadasys furcatus (Bloch et Schneider) and Transvena pichelinae n. sp. from Thalassoma purpureum (Forsskål). Transvena pichelinae n. sp. differs from the single existing species of the genus Transvena annulospinosa Pichelin et Cribb, 2001, by the lower number of longitudinal rows of hooks (10-12 vs 12-14, respectively) and fewer hooks in a row (5 vs 6-8), shorter blades of anterior hooks (55-63 vs 98), more posterior location of the ganglion (close to the posterior margin of the proboscis receptacle vs mid-level of the proboscis receptacle) and smaller eggs (50-58 × 13 µm vs 62-66 × 13-19 µm). Pararhadinorhynchus sodwanensis n. sp. differs from all known species of the genus by a combination of characters. It closely resembles unidentified species Pararhadinorhynchus sp. sensu Weaver and Smales (2014) in the presence of a similar number of longitudinal rows of hooks on the proboscis (16-18 vs 18) and hooks in a row (11-13 vs 13-14), but differs in the position of the lemnisci (extend to the level of the posterior end of the proboscis receptacle or slightly posterior vs extend to the mid-level of the receptacle), length of the proboscis receptacle (910-1180 µm vs 1,460 µm) and cement glands (870-880 µm vs 335-350 µm). Rhadinorhynchus gerberi n. sp. is distinguishable from all its congeners by a single field of 19-26 irregular circular rows of the tegumental spines on the anterior part of the trunk, 10 longitudinal rows of hooks on the proboscis with 29-32 hooks in each row, subterminal genital pore in both sexes, and distinct separation of the opening of the genital pore from the posterior edge of the trunk (240-480 μm) in females., a2_Sequences for the 18S rDNA, 28S rDNA and cox1 genes were generated to molecularly characterise the species and assess their phylogenetic position. This study provides the first report based on molecular evidence for the presence of species of Transvena Pichelin et Cribb, 2001 and Pararhadinorhynchus Johnston et Edmonds, 1947 in African coastal fishes., Olga I. Lisitsyna, Olena Kudlai, Thomas H. Cribb, Nico J. Smit., and Obsahuje bibliografii
Three species of Pseudodactylogyrus Gusev, 1965 (Monogenea: Pseudodactylogyridae) were collected from the gills of Anguilla reinhardtii Steindachner and A. australis Richardson from several localities in Australia and eels imported to Japan from Australia. Pseudodactylogyrus gusevi sp. n. from A. reinhardtii (type host) and A. australis in Queensland, Australia is most similar to P. bini (Kikuchi, 1929), but can be differentiated by the shorter male copulatory tube, heavy sclerotisation of the vaginal tube and the presence of a small projection of the supplementary piece of the hamulus. Pseudodactylogyrus rohdei sp. n. from A. australis (type host) in Queensland, Australia is most similar to P. anguillae (Yin et Sproston, 1948), but differs in the possession of a longer cement gland and the presence of a small projection on the supplementary piece of the hamulus. Pseudodactylogyrus bini sensu Gusev, 1965 and P. anguillae sensu Gusev, 1965 are synonymised with P. gusevi sp. n. and P. rohdei sp. n., respectively. Pseudodactylogyrus mundayi sp. n. from A. australis, originating in Tasmania, Australia and sent alive to Japan, is most similar to P. kamegaii Iwashita, Hirata et Ogawa, 2002, from which it can be discriminated by the shorter male copulatory tube and the shorter vaginal tube. Dactylogyrus bialatus Wu, Wang et Jian, 1988 from Synechogobius ommaturus (Richardson) (Gobiidae) is transferred to Pseudodactylogyrus as P. bialatus comb. n. A phylogenetic tree based on the ITS2 region of six species of Pseudodactylogyrus including P. gusevi and P. mundayi shows that P. haze from a goby diverged first, and that species from eels are monophyletic, forming three lineages differing by their zoogeographical distribution. With the three new species and one new combination proposed in this paper, Pseudodactylogyrus is now comprised of eight species infecting anguillid and gobiid fish, and a key to species is presented., Kazuo Ogawa, Makoto Iwashita, Craig J. Hayward, Akira Kurashima., and Obsahuje bibliografii
This review considers factors affecting the flight capacity of carabid beetles and the implications of flight for carabids. Studies from the Dutch polders in particular show that young populations of carabids consist predominantly of macropterous species and macropterous individuals of wing-dimorphic species. Also populations of wing-dimorphic carabid species at the periphery of their geographical range contain high proportions of macropterous individuals. However, studies from Baltic archipelagos show that older populations of even highly isolated island habitats contain considerable proportions of brachypterous species and individuals. This suggests that macroptery is primarily an adaptation for dispersal and that there exists a mechanism for subsequently reducing the ratio of macropterous to brachypterous species under stable conditions, due to the competitive advantage of brachyptery. Populations in isolated habitats, such as islands and mountains, have high proportions of brachypterous species. Many macropterous species do not possess functional flight muscles. Species of unstable habitats, such as tree canopies and wet habitats, are mostly macropterous. Brachypterous species tend to disappear from disturbed habitats. There is uncertainty regarding the extent to which carabid dispersal is directed and how much passive. Both Den Boer and Lindroth recognized that mostly macropterous individuals of macropterous and wing-dimorphic species disperse and found new populations, after which brachyptery tends to rapidly appear and proliferate in the newly founded population. It is most likely that the allele for brachyptery would arrive via the dispersal of gravid females which had mated with brachypterous males prior to emigration. Whilst many studies consider wing morphology traits of carabid beetles to be species-specific and permanent, a number of studies have shown that the oogenesis flight syndrome, whereby females undertake migration and subsequently lose their flight muscles by histolysis before eventually regenerating them after reproducing, has been reported for a growing number of carabid species. Wing morphology of carabid beetles clearly offers strong potential for the study of population dynamics. This field of study flourished during the 1940's to the late 1980's. Whilst a considerable amount of valuable research has been performed and published, the topic clearly holds considerable potential for future study., Stephen Venn., and Obsahuje bibliografii
Growth of the tocopherol-deficient vte1 mutant and Col-0 wild type of Arabidopsis thaliana in a sunlit glasshouse revealed both similarities and differences between genotypes. Photosynthetic capacity and leaf mesophyll features did not differ between mutant and wild type. Likewise, the total volume of water conduits (tracheary elements, TEs), sugar conduits (sieve elements, SEs), and sugar-loading cells (companion and phloem parenchyma cells) on a leaf area basis were unaffected by tocopherol deficiency. However, tocopherol deficiency yielded smaller and more numerous minor veins with fewer phloem cells and smaller TEs, resulting in greater ratios of TEs to SEs. The smaller TEs in the vte1 mutant may present a decreased risk for cavitation under high evaporative demand or in response to freezing. In turn, compensation for fewer phloem cells and smaller TEs by more numerous veins may bolster resistance to cavitation at no cost to photosynthetic capacity., J. J. Stewart, W. W. Adams, C. M. Cohu, B. Demmig-Adams., and Obsahuje bibliografické odkazy
Cadmium is often detected in areas contaminated by heavy metals and the incidence of this element in dangerous concentrations has been increasing due to anthropogenic activities. The aim of this research was to determine Cd concentrations in tissues, quantify compounds, pigments and enzymes, and to evaluate the gas exchange. Our aim was also to identify components that can modify and contribute to tolerance of Cassia alata against Cd toxicity. We used five Cd concentrations (0, 22, 44, 88, and 132 μM) to validate our hypothesis. The Cd concentrations in tissues of C. alata plants increased significantly, compared with the control treatment, in the following graduated sequence: root > leaf > stem. Progressive enhancement in glutathione (GSH) was verified in plants treated with all Cd concentrations used, when compared with treatment without Cd. Antioxidant enzyme activities presented similar patterns with progressive enhancements, being a desirable characteristic for plants with a potential to hyperaccumulate Cd. Our results suggest that C. alata plants can be used for phytoremediation programs. Their defense mechanism is based on Cd accumulation in roots, coupled with increase in GSH and the efficient activity of antioxidant enzymes that contribute to minimize the oxidative stress and consequently improve the protection of the metabolic machinery., J. R. R. Silva, A. R. Fernandes, M. L. Silva Junior, C. R. C. Santos, A. K. S. Lobato., and Obsahuje bibliografii
Increase in salinity is predicted to affect plant growth and survival in most arid and semiarid regions worldwide. Mitragyna parvifolia (Roxb.) Korth. is an important medicinal tree species distributed throughout the semiarid regions of India; however, it is facing a threat of its extinction in its natural habitat. We examined the effects of increasing NaCl salinity on two-month-old M. parvifolia seedlings grown in an environment-controlled chamber and exposed to soils of different electrical conductivity (EC) caused by NaCl [0-5 (control), 5-10, 10-15, 15-20, and 20-25 dS m-1)] for 85 days. Seedlings transferred to soil of EC >15 dS m-¹ did not survive beyond 1 week. Increase in the Na+ concentration negatively correlated with their height and positively correlated with their water-use efficiency (WUE). However, leaf area, net photosynthetic rate (PN), stomatal conductance, and transpiration rate showed varying correlations and an overall decrease in these parameters compared with the control. At EC of 10-15 dS m-1, the seedling height was reduced by 37% and PN was lowered by 50% compared with those of the control. An increase in the Na+/K+ ratio was observed with increasing salinity. The maximum quantum efficiency of PSII significantly decreased with increasing salinity compared with the control. Our results suggest that the increase in salinity reduced the overall performance of the M. parvifolia seedlings. However, the maintenance of WUE and maximum quantum efficiency of PSII might help M. parvifolia to tolerate NaCl salinity of 15 dS m-1., A. Bidalia, M. Hanief, K. S. Rao., and Obsahuje bibliografii
This study investigated whether gas exchange and the present content of antioxidant compounds can contribute to the survival of Euterpe oleracea plants in environments of frequent waterlogging. A factorial randomised, experimental design included two distinct water conditions (waterlogging and control) and five evaluation times (0, 6, 12, 18, and 24 d). Gasexchange parameters, leaf temperature, electrolyte leakage, and contents of antioxidant compounds were measured. Waterlogging did not promote significant alterations in net photosynthetic rate and transpiration, and stomatal conductance was reduced only after 18 d. Malondialdehyde and glutathione contents did not significantly change during waterlogging. Additionally, electrolyte leakage was significant only after 18 d of waterlogging. Thus, this study revealed that maintenance in gas exchange and antioxidant compounds might contribute to the survival of E. oleracea plants in environments exposed to waterlogging., T. S. Pereira, A. K. S. Lobato, G.A.R. Alves, R.N. Ferreira, O.N. Silva, A. P. Martins Filho, E.S. Pereira, L.S. Sampaio., and Obsahuje bibliografii