Search results for "Gill"

Development of monogenean communities on the gills of roach fry (Rutilus rutilus).

1999

The formation and development of monogenean communities on the gills of roach fry was followed in 1992 from early June to October (size range 9 to 47 mm). Roach fry (n=291) were sampled weekly from the small, humic River Rutajoki in central Finland. A further 209 roach fry were reared in a fish farm supplied by water from the river. Four Dactylogyrus species were found: D. nanus, D. crucifer, D. micracanthus and D. suecicus. Other species found on the gills were Gyrodactylus sp. and Paradiplozoon homoion. The first Dactylogyrus juvenile occurred on a 12 mm long fish fry in late June and the first adult (D. nanus) 1 week later in Tank 1. D. nanus was also the most common parasite in the rive…

Effects of sublethal exposure to lead on levels of energetic compounds in Procambarus clarkii (Girard, 1852).

1994

Lead is neither essential nor beneficial to living organisms; all existing data show that its metabolic effects are adverse. Lead is toxic to all phyla of aquatic biota. Most of the lead discharged into surface water is rapidly incorporated into suspended and bottom sediments. The American red crayfish, Procambarus clarkii, lives in a wide range of environmental conditions that include highly polluted waters. Lead present in take sediments can be available to aquatic animals such as P. clarkii because it is a detritivor and burrow into the sediment. In fact, we found remarkable levels of lead in tissues of P. clarkii caught in Albufera Lake and kept 15 days in clean water (e. g. 223 [mu]g/g…

Diclidophora merlangi (Monogenea: Diclidophoridae) on Atlantic cod, Gadus morhua.

2006

Diclidophora merlangi (Kuhn, in Nordmann, 1832), as species specific to whiting, Merlangius merlangus (Linnaeus, 1758), is reported and described for the first time on the gills of Atlantic cod Gadus morhua (Linnaeus, 1758). Of the about 1,200 cod examined in this article, only 2 specimens of D. merlangi occurred on 2 fish, suggesting that they represented accidental infections. The 2 specimens showed specific traits of D. merlangi, but their size was considerably smaller than that of D. merlangi on whiting. Principal-component analyses showed that the morphology of the specimens on cod was more similar to that of D. merlangi than those of other congeneric species from the North Atlantic, a…

Changes in biochemical composition of gills, hepatopancreas and muscle of the red crayfish Procambarus clarkii (Girard) after sublethal exposure to m…

1992

Abstract 1. 1. The changes in the biochemical composition of gills, hepatopancreas and muscle after exposure to 0.25 mg Hg/l were studied in Procambarus clarkii . 2. 2. Sublethal exposure to mercury in P. clarkii resulted in significant decreases in protein concentration and caloric concentration in gills over the 96 hr period. Glycogen/lipid and glycogen/protein ratios increased after 48 and 96 hr of mercury exposure. 3. 3. Lipid and caloric concentration in the hepatopancreas were significantly lower in 96 hr mercury exposed group. 4. 4. Glycogen concentration in muscle was depleted as consequence of 96 hr mercury exposure.

Skoulekia meningialis n. gen., n. sp. (Digenea: Aporocotylidae Odhner, 1912) a parasite surrounding the brain of the Mediterranean common two-banded …

2010

This study describes a new aporocotylid genus and species, Skoulekia meningialis n. gen., n. sp. which was detected in the ectomeningeal veins surrounding the optic lobes of the brain of the common two-banded seabream Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817) from the Gulf of Valencia (Mediterranean Sea). A detailed morphological description of S. meningialis is provided, including drawings, measurements and scanning electron microscopy images as well as a phylogenetic study of S. meningialis and closely related taxa using DNA sequence data obtained from whole ITS2 and partial 18S and 28S rDNA regions. Morphology as well as molecular phylogeny strongly support the erection of a new g…

Effect of hypoosmotic stress by low salinity acclimation of Mediterranean mussels Mytilus galloprovincialis on biological parameters used for polluti…

2008

In the present study, we investigated the progressive acclimation of the mussel Mytilus galloprovincialis to different reduced seawater (SW) salinities and its effect on several biochemical markers and biotests. Mussels were purchased from a local mariculture facility during summer (SW temperature 27 degrees C, salinity 37.5 psu) and winter (13 degrees C, 37 psu) seasons, and transferred to the laboratory for acclimation to reduced SW salinities (37, 28, 18.5 and 11 psu). At the beginning and at the end of acclimation processes tests of mussel survival in air were provided. After 14 days of acclimation the DNA integrity, p38-MAPK activation, metallothionein induction, oxygen consumption rat…

Acute toxicity and oxygen consumption in the gills of Procambarus clarkii in relation to chlorpyrifos exposure.

1992

Ligophorus pilengas n. sp. (monogenea: ancyrocephalidae) from the introduced so-iuy mullet, mugil soiuy (teleostei: mugilidae), in the sea of Azov an…

2004

The monogenean Ligophorus chabaudi was originally described on the gills of the flathead mullet, Mugil cephalus, and was subsequently reported on the So-iuy mullet, Mugil soiuy. However, the morphology of sclerotized parts and multivariate statistical analyses suggest that the form from the So-iuy mullet represents a new species. This study provides a description of the new species Ligophorus pilengas n. sp. and provides additional morphological data concerning the morphology of the ventral bar that might be useful for the diagnosis of Ligophorus. Ligophorus pilengas n. sp. is the second species of Ligophorus reported on the So-iuy mullet. Zoogeographical records indicate that L. pilengas n…

Role of the metalloprotease Vvp and the virulence plasmid pR99 of Vibrio vulnificus serovar E in surface colonization and fish virulence.

2007

The virulence for eels of Vibrio vulnificus biotype 2 serovar E (VSE) is conferred by a plasmid that codifies ability to survive in eel serum and cause septicaemia. To find out whether the plasmid and the selected chromosomal gene vvp plays a role in the initial steps of infection, the VSE strain CECT4999, the cured strain CT218 and the Vvp-deficient mutant CT201 (obtained in this work by allelic exchange) were used in colonization and virulence experiments. The eel avirulent biotype 1 (BT1) strain YJ016, whose genome has been sequenced, was used for comparative purposes. The global results demonstrate that the plasmid does not play a significant role in surface colonization because (i) CEC…

Effects of waterborne iron overload and simulated winter conditions on acute physiological stress response of whitefish, Coregonus lavaretus

2003

Two-year-old whitefish (Coregonus lavaretus) were exposed for 30 days to episodic iron overload in iron-rich humic water (5%) supplemented with inorganic iron (5 mg FeL(-1)). Two parallel laboratory exposures were performed, one under conditions simulating winter and the other under conditions simulating spring. After exposure, some of the fish were subjected to acute handling stress in the form of a short air challenge to reveal possible modification of the primary and secondary stress responses. In whitefish sampled without additional handling, iron accumulated in the liver (under spring conditions) and gills (under winter and spring conditions); plasma catecholamine and beta-estradiol (b…