Citharichthys Research Articles

백석의 수필과 시의 연관성 연구-「가재미, 나귀」, 「무지개 뻗치듯 만세교」, 「선우사」, 「나와 나타샤와 흰 당나귀」를 중심으로-

백석의 수필과 시의 연관성 연구-「가재미, 나귀」, 「무지개 뻗치듯 만세교」, 「선우사」, 「나와 나타샤와 흰 당나귀」를 중심으로-

A Study on ‘Giyoung Lee’s Selection’, A Collection of North Josun Canons -Again, thinking of the boundary of modern literature-

A Study on ‘Giyoung Lee’s Selection’, A Collection of North Josun Canons -Again, thinking of the boundary of modern literature-

RETRACTED ARTICLE: Efficient detection of pathogen virus in sand dabs, Paralichthys olivaceus using loop-mediated isothermal amplification (LAMP)

Viral hemorrhagic septicemia virus (VHSV) and marine birnavirus (MABV) are the causative pathogens for some of the most explosive epidemics of emerging viral diseases in many Asian countries, leading to huge economic losses in aquaculture. Rapid molecular detection for surveillance or diagnosis has been a critical component in reducing the prevalence of pathogen infection. The loop-mediated isothermal amplification (LAMP) of DNA is currently one of the most commonly used molecular diagnostic tools, as it is simple, quick, and easy to amplify target DNA under isothermal conditions. In the present study, a novel and highly specific LAMP assay for the sensitive and rapid detection of VHSV and MABV infection in fish was developed. Using a set of synthesized primers matching a specific region of the genome, the efficiency and specificity of the LAMP assay were optimized in terms of the reaction temperature and DNA polymerase concentration, as they are the main determinants of the sensitivity and specificity of the LAMP assay. In particular, we demonstrated that our assay could be applied to efficient detection of VHSV and MABV infection in the wild fish, Paralichthys olivaceus. Our results demonstrate the simplicity and convenience of this method for the detection of viral infection in aquatic organisms.

魚介類筋肉のイノシン分解酵素の特性

Activities of inosine (HxR)-decomposing enzymes (purine nucleoside phospholylase and HxR nucleosidase) in the muscle of twenty four species of aquatic animals were compared. The enzyme activities in HxR accumulating species were very low. On the other hand, the activities in hypoxanthine (Hx) accumulating species were generally higher in the absence than in the presence of phosphate. Some species of plaice, squid and octopus showed relative-ly higher activity. The activity of common squid enzyme was the highest of the species examined. In the absence of phosphate, the pH optima of the activity of sand dab and common squid enzymes were found to be around 8.5 and 6.5, respectively. The Km values for HxR of sand dab and common squid enzymes were 5.72×10-4 and 1.59×10-4M, respectively. Although the sand dab enzyme was remarkably depressed by phosphate, the common squid enzyme was not affected. HxR nucleosidase of fishes was activated three times as high as the ordinary level by 0.5mM Ca2+, while the molluscan enzyme was not affected by Ca2+.

Physiological properties of three muscle fibre types controlling dorsal fin movements in a flatfish, Citharichthys sordidus.

Pacific sand dabs utilize their dorsal and anal fins in different behaviours which are characterized by extremely rapid fin movements, on one hand, and essentially isometric force generation on the other. Muscle fibres controlling fin movements were examined physiologically. Direct electrical shocks to localized regions of fin muscles reveal three fibre types. The longest fibres in the muscle are very fast and functionally analogous to frog twitch fibres. The shortest fibres are extremely, slow and show properties much like frog tonic fibres. The mid-length fibres produce contractile responses which are intermediate in time course. Even the fastest muscle fibres do not generate action potentials, but instead rely on summating junction potentials to drive membrane voltage to a stable level just beyond contraction threshold (-35 to -40 mV). Twitch amplitude can be finely graded by the time that membrane depolarization exceeds this threshold level.

Golgi stain identifies three types of fibres in fish muscle

Using Golgi infiltration we have studied the structure and disposition of transverse tubules in muscle fibres from the sand dab fin musculature. Three types of fibres differ significantly from each other in the extent and disposition of junctions between transverse tubules and the sarcoplasmic reticulum. These correlate with the three groups of fibres having different relaxation times shown in the accompanying paper (Gilly & Aladjem, 1987). Fibres with very slow relaxation (tonic fibres) correspond to those which have an unusual disposition of T tubules and very rare T-SR junctions. In the fast twitch fibres the peripheral T tubules segments converge into tangentially arranged tubules before joining the plasmalemma.

Experimental Analyses of Structural Regulation in a Marine Sand Community Exposed to Oceanic Swell

The development of general theories concerning the origin and maintenance of community organization in marine sedimentary environments will benefit from studies of similar processes in the widest possible range of habitat types. The roles of predation and disturbance by large epibenthos are thought to be significant in many such habitats, but the bulk of recent experimental confirmation comes from shallow areas protected from oceanic swell. This field experimental study examines relationships among demersal predators, predator—caused local disturbance, infauna, and infaunal food resources in an exposed marine sand habitat at 17—m depth in southern California, USA. Manipulation of predator densities with exclusion cages, simulation of biological disturbance, and study of dispersal and habitat selection of infauna showed the importance of recurrent local disturbances by the rays Urolophus halleri and Myliobatis californica, which dig pits to expose prey but clear other infauna in the process. Benthic invertebrate populations show complex but reproducible patterns of reoccupation of disturbed sites. The most striking aspect of these patterns is active selection of recently formed pits by certain species. Ray pits are sites of accumulation for organic material on which most of the infauna feed. Experiments showed that populations which rapidly colonize new ray pits are responding to the concentration of food resources which are otherwise sparsely distributed. Responses of infauna to ray disturbance are correlated with postlarval swimming capability and method of feeding. Early colonists are active nocturnal swimmers that feed on detritus at the sand—water interface. Such features allow efficient exploitation of patchy, ephemeral concentrations of organic matter. Later arrivals are primarily subsurface feeders with limited swimming activity. The relative abundances of infauna are sensitive to seasonal changes in ray disturbance rates. Early pit colonists predominate when disturbance rates are high. The ray disturbance phenomenon produces a persistent mosaic of patches in various stages of infaunal recolonization. Other experiments showed the importance of predation by sea stars (Astropecten verrilli) and speckled sand dabs (Citharichthys stigmaeus). Sea stars consume crab larvae soon after they settle to the bottom and begin metamorphosis. During the study, recruitments of two crabs, Cancer gracilis and Portunus xantusii, were much reduced by sea star predation. A caging experiment indicated that high—density populations of P. xantusii have important negative effects on some infaunal populations. Thus, sea star predation on young crabs is important to the maintenance of infaunal community organization. Sand dabs consume infauna which are flushed into the water column or onto the sand surface by digging rays. This commensal behavior constitutes an important additional source of mortality for populationsthat are otherwise unavailable as food for sand dabs, which are visual predators.

COPEPODS OF THE FAMILIES LERNAEOPODIDAE AND NAOBRANCHIIDAE PARASITIC ON FISHES FROM SOUTHERN CALIFORNIA INSHORE WATERS

ABSTRACT Three morphological forms of the female of Neobrachiella robusta from three species of Sebastes are described along with the first description of the male. Three new species of parasitic copepods are described and illustrated. They are: Clavella embiotocae, new species, from the gill filaments of Embiotoca jacksoni, Rhacochilus vacca, and Phanerodon furcatus; Naobranchia microsoma. new species, from the gill filaments of Genyonemus lineatus, Citharichthys stigmaeus, C. sordidus, and C. xanthostigma; and Naobranchia scorpaenae,new species, from the gill filaments of Scorpaena guttata. All copepods collected parasitized fishes caught in benthic trawls at the Orange County sewer outfall, California, between October 1975 and August 1976.

Purine metabolism in primitive erythrocytes

1. 1. The activities of AMP kinase, GMP kinase, NDP kinase, PNPase and HGPRTase were determined in the erythrocytes of seal, eel, hagfish and dogfish. 2. 2. Erythrocytic NDP kinase activities were high and electrophoretically heterogeneous in all species examined. 3. 3. Patterns of nucleotide extracts of whole blood and erythrocytes in seal, sand dab, skate, hagfish, dogfish, nurse shark and stingray were similar when determined by high-pressure liquid chromatography. Patterns of the whole blood of eel and lemon shark, however, were strikingly different in containing large amounts of GDP and GTP.

Uptake, metabolism and discharge of polycyclic aromatic hydrocarbons by marine fish

The uptake, metabolism and discharge of two polycyclic aromatic hydrocarbons, 14C-naphthalene and 3H-3,4-benzopyrene, were studied in 3 species of marine fish (mudsucker or sand goby, Gillichthys mirabilis; sculpin, Oligocottus maculosus; sand dab, Citharichthys stigmaeus). The path of hydrocarbons through the fish included entrance through the gills, metabolism by the liver, transfer of hydrocarbons and their metabolites to the bile, and, finally, excretion. The gall bladder was a major storage site of labeled hydrocarbons and their metabolites. The major product of 2H-3,4-benzypyrene metabolism was tentatively identified as 7,8-dihydro-7,8-dihydroxybenzopyrene. The 14C-naphthalene was metabolized to 1,2-dihydro-1,2-dihydroxynaphthalene after 24 h exposure. The urine appeared to the major avenne for discharge of labeled hydrocarbon from the body. Our laboratory results indicated that certain polycyelic aromatic hydrocarbons were rapidly taken up from seawater by the above fish, but detoxification mechanisms existed for efficient removal of these compounds from their body tissues.

Observations on the morphology and life-history of the digenetic trematode, Lepocreadium setiferoides (Miller and Northup, 1926) Martin, 1938.

Cercaria setiferoides, an ophthalmotrichocercous distome larva from Nassa obsoleta, was described by Miller and Northup (1926). Its life-cycle was reported by Martin (1938) and the excretory system was studied by Peters (1961). Martin found the larvae encysted as metacercariae in the turbellarian, Procerodes warreni, and in the annelid, Spio sp. The final hosts were small flounders and sand dabs. There are serious disagreements and discrepancies in the three accounts and a redescription of the successive stages in the life-cycle provides new information as well as the correction of previous errors. Experimental infections have disclosed new secondary intermediate hosts and the adult stage is regarded as identical with worms described by Linton (1940) as Lepocreadium trullaforme n. sp. But L. trullaforme was suppressed by Yamaguti (1958) as a synonym of Distomum areolatum Rudolphi of Linton, 1900, and Stunkard (1969b) redescribed that species as Lepocreadium areolatum (Linton, 1900) n. comb. This taxonomic...

STUDIES ON TREMATODES OF WOODS HOLE: THE LIFE CYCLE OF LEPOCREADIUM SETIFEROIDES (MILLER AND NORTHUP), ALLOCREADIIDAE, AND THE DESCRIPTION OF CERCARIA CUMINGIAE N. SP.

The life cycle of Lepocreadium setiferoides (Miller and Northup) has been experimentally traced. The rediae and cercariae develop in the snail, Nassa obsoleta; the cercariae encyst in annelids of the genus Spio and the turbellarian, Procerodes warreni; and the adult worm develops in the intestine of sand dabs and flounders. The structures of the various stages in the life cycle are described.The anatomical features and most of the life cycle of Cercaria cumingiae n. sp. are described. The sporocysts and cercariae develop in the digestive gland of the bilvalve, Cumingia tellinoides. The cercariae encyst in the siphons, foot, and other organs of this mollusk. The adult worm probably develops in some fish. From the nature of the excretory bladder, the flame cell pattern, and the location of the genital primordium, it is believed that this trematode belongs to the family Allocreadiidae.

CITHARICHTHYS STIGMAEUS AS A POSSIBLE INTERMEDIATE HOST OF GILQUINIA SQUALI (FABRICIUS)

Feeding cysts from Citharichthys to Squalus gave tapeworms considered as G. squall.