A new nematode species, Spirophilometra pacifica sp. n. (Philometridae), is described from gravid female specimens collected from the mouth cavity (the upper palate) of the fish (yellow snook) Centropomus robalito (Centropomidae, Perciformes) from the Chantuto-Panzacola system, Chiapas, in the Pacific coast of Mexico. Its morphology is very similar to that of the species originally described as Philometra centropomi Caballero, 1974, but the gravid females of S. pacifica are about three times longer (body length 11.63-18.17 mm); host species and the geographical distribution of both these forms also differ. Scanning electron microscope (SEM) examination of S. pacifica, used for the first time for a Spirophilometra species, confirmed the presence of numerous minute cuticular spines on the body surface, 14 cephalic papillae arranged in two circlets, and two small lateral papilla-like caudal projections. It is evident that some features of P. centropomi were incorrectly described (its types are not available) and this species is now transferred to Spirophilometra as S. centropomi (Caballero, 1974) comb. n.
A new species of Taeniacanthidae (Copepoda, Cyclopoida), Taeniacanthus kiemae sp. n., is described based on adult female and male specimens collected from the branchial cavity wall of Marilyna meraukensis (de Beaufort) and M. darwinii (Castelnau) (Teleostei, Tetraodontidae) caught in Australian waters. The new species differs from its congeners by having the following combination of characters in the adult female: 1) maxilla armed with a stout terminal process and two small elements; 2) multiple rows of spinules on the large pectinate process of the antenna; 3) an extremely long and thin maxilliped claw; 4) second exopodal segment of leg 1 with eight setae; 5) third exopodal segment of leg 3 with three spines and four setae; 6) third exopodal segment of leg 4 with three spines and two setae; and 7) each spine on the free exopodal segment of leg 5 with a subterminal flagellum. Taeniacanthus kiemae is the second copepod species reported from M. meraukensis and M. darwinii and the first taeniacanthid species reported from pufferfishes in Australia.
Rhinozachvatkinia calonectris sp. n., a new species of the feather mite genus Rhinozachvatkinia Mironov, 1989 (Avenzoariidae: Bonnetellinae), is described from two species of shearwaters in the North-East of the Atlantic Ocean, Calonectris edwardsii (Oustalet) (type host) and Calonectris borealis (Cory) (Procellariiformes: Procellariidae). We completed the morphological description of this new feather mite species with sequence data on the mitochondrial cytochrome c oxidase subunit I gene fragment (COI). The full generic status of Rhinozachvatkinia, originally established as a subgenus of Zachvatkinia Dubinin, 1949, is formally fixed and its systematic relationships are briefly discussed.
In a study of the benthic polychaete fauna of the southern Gulf of Mexico and the Caribbean Sea, several specimens of the terebellid polychaete Scionides reticulata (Ehlers) were found to host endoparasitic copepods that represent an undescribed species of the rare cyclopoid genus Entobius Dogiel, 1948. The new species, E. scionides sp. n., can be distinguished from its congeners by a combination of characters including a genital region without constrictions, three-segmented antennules, a reduced antenna with a blunt terminal process, reduced ornamentation of endopods of legs 1-4 and its relatively small size (2.3-2.7 mm). It is the smallest species of the genus. Comments on immature females are also provided, but males of this species remain unknown. It has a high prevalence (53%) in populations of the terebellid S. reticulata in the southern Gulf of Mexico, but it is absent from the Caribbean. This is the first occurrence of this copepod genus in the Americas. The finding of the new species of Entobius in S. reticulata confirms the strict specificity of most members of the genus and expands the host range of this copepod genus. A key for the identification of the species of Entobius is provided.
The adult morphology is described and illustrated of Neoplagioporus kajika sp. n. (Digenea: Opecoelidae) found in the Japanese fluvial sculpin Cottus pollux Günther (Osteichthyes: Scorpaeniformes: Cottidae) collected in the Naka River at Terase Bridge, Narutake, Nakagawa Town, Fukuoka Prefecture, Kyushu, Japan. This new species is characterized by that the body shape is oval, that the intestinal caeca end posteriorly at the middle level of the testicular region, that the ovary is trilobed, and that the vitelline follicles are distributed between the pharyngeal level and usually the posterior end of body and fill up the lateral fields of body. The new species is different from three hitherto known Neoplagioporus species, N. zacconis (Yamaguti, 1934) Shimazu, 1990 (type species), N. ayu (Takahashi, 1928) Shimazu, 1990, and N. elongatus (Goto et Ozaki, 1930) Shimazu, 1990, in a combination of these characteristics. The new species is considered mainly infective to C. pollux in the river.
By investigating the RD-Ca (dark respiration rate-atmospheric CO2 concentration) and PN (net photosynthetic rate)-Ca curves of bamboo (Fargesia denudata) and poplar (Populus cathayanna), we found that: (1) the minimal RD was close to ambient CO2 concentration, and the elevated or decreased atmospheric CO2 concentration enhanced the RD of both species; (2) the response curves of RD-Ca were simulated well by quadratic function. This phenomenon might be an inherent property of leaf R of F. denudata and P. cathayanna. If this was true, it implies that effect of CO2 on
RD could be interpreted with the relationship of RD-Ca curves and the quadratic function. and Y.-Z. Qiao ... [et al.].
The transfer of light energy from phycobilisomes (PBS) to photosystem II (PSII) reaction centers is vital for photosynthesis in cyanobacteria and red algae. To investigate the relationship between PBS and PSII and to optimize the energy transfer efficiency from PBS to PSII, isolation of the PBS-PSII supercomplex is necessary. SPC (sucrose/phosphate/citrate) is a conventional buffer for isolating PBS-PSII supercomplex in cyanobacteria. However, the energy transfer occurring in the supercomplex is poor. Here, we developed a new buffer named SGB by adding 1M glycinebetaine and additional sucrose to SPC buffer. Compared to SPC, the newly developed SGB buffer greatly enhanced the associated populations of PBS with thylakoid membranes and PSII and further improved the energy transfer efficiency from PBS to PSII reaction centers in cyanobacteria in vitro. Therefore, we conclude that SGB is an excellent buffer for isolating the PBS-PSII supercomplex and for enhancing the energy transfer efficiency from PBS to PSII reaction centers in cyanobacteria in vitro., L. P. Chen, Q. X. Wang, W. M. Ma., and Obsahuje bibliografii
The objective of this paper is to simulate flow frequency distribution curves for Amazon catchments with the aim of scaling power generation from small hydroelectric power plants. Thus, a simple nonlinear rainfall-runoff model was developed with sigmoid-variable gain factor due to the moisture status of the catchment, which depends on infiltration, and is considered a factor responsible for the nonlinearity of the rainfall-runoff process. Data for a catchment in the Amazon was used to calibrate and validate the model. The performance criteria adopted were the Nash-Sutcliffe coefficient (R²), the RMS, the Q95% frequency flow percentage error, and the mean percentage errors ranging from Q5% to Q95%.. Calibration and validation showed that the model satisfactorily simulates the flow frequency distribution curves. In order to find the shortest period of rainfall-runoff data, which is required for applying the model, a sensitivity analysis was performed whereby rainfall and runoff data was successively reduced by 1 year until a 1.5-year model application minimum period was found. This corresponds to one hydrological year plus the 6-month long ''memory''. This analysis evaluates field work in the ungauged sites of the region. and Cieľom tohto príspevku je simulácia čiar rozdelenia prietokov pre povodia rieky Amazonka pre potreby hodnotenia premeny energie v malých hydroelektrárňach. Preto bol vyvinutý jednoduchý nelineárny zrážko-odtokový model so sigmoidálne sa meniacim zdrojovým faktorom v závislosti od obsahu vody v povodí, ktorý závisí od infiltrácie a je považovaný za faktor, spôsobujúci nelinearitu zrážkoodtokových procesov. Pre kalibráciu a validizáciu modelu boli použité údaje z povodí rieky Amazonka. Použili sme tieto hodnotiace kritériá: Nashov-Sutcliffov koeficient (R²), RMS, Q95%, chyba určenia odtoku v percentách, a priemerná percentuálna chyba v rozsahu od Q5% do Q95%. Kalibrácia a validizácia ukázala, že model simuluje čiary rozdelenia prietokov uspokojivo. Aby bolo možné nájsť najkratšie obdobie pre nájdenia závislosti zrážky - odtok, ktorá je potrebná pre aplikáciu v modeli, použili sme citlivostnú analýzu tak, že údaje zrážky - odtok boli postupne redukované o jeden rok, až kým nebolo nájdené minimálne obdobie pre aplikáciu vzťahu zrážky - odtok 1,5 roka. Toto obdobie zodpovedá jednému hydrologickému roku, plus 6 mesiacov dlhá ''pamäť''. Touto analýzou boli vyhodnotené výsledky terénnych meraní v oblastiach, kde neboli k dispozícii merania odtoku.
Controversial aspects of the conventional and widely used concept of the integral vortex strength are briefly discussed. The strength of a vortex is usually calculated as the circulation along the vortex boundary, or equivalently due to Green’s theorem, as the surface integral of vorticity over the planar vortex cross section. However, the local effect of an arbitrary ''superimposed shear'' is fully absorbed by vorticity what makes the circulation a shear-biased vortex characteristic. The present paper shows that different vortexstrength models can be derived on the basis of different local vortex intensities proposed in the literature. The outcome of these models naturally differs, even for an ideally axisymmetric vortex. Three different vortex-strength models are compared and discussed by examining the unsteady Taylor vortex. and V práci jsou stručně diskutovány sporné stránky konvenčního a široce užívaného pojetí integrální síly víru. Síla víru je obvykle počítána jako cirkulace podél hranice víru nebo ekvivalentně podle Greenovy věty jako plošný integrál vířivosti přes příčný rovinný řez vírem. Lokální efekt libovolného ''superponovaného smyku'' je však plně absorbován vířivostí, což činí z cirkulace smykově zkreslenou vírovou charakteristiku. Tento článek ukazuje, že lze odvodit různé modely síly víru na základě různých lokálních intenzit víru navržených v odborné literatuře. Výsledky těchto modelů se přirozeně liší, dokonce i pro ideálně osově symetrický vír. Na podkladě zkoumání nestacionárního Taylorova víru jsou porovnány a diskutovány tři různé modely síly víru.