Search results for " Fish"

Descending Connections from the Brainstem to the Spinal Cord in the Electric Fish <i>Eigenmannia</i>

1990

The descending connections from the brainstem to the spinal cord in Eigenmannia sp. were demonstrated using the horseradish peroxidase (HRP) technique. The spinal cord was transecte

Fishless-stream mayflies express behavioural flexibility in response to predatory fish

1996

The fish avoidance behaviour of nymphs of the grazing mayfly Baetis rhodani (Ephemerop- tera) was examined. The nymphs originated from a fishless stream. To study their responses to the addition of predator cues, nymphs were exposed to (1) chemical cues from a caged fish, or (2) a freely moving diurnal fish (European minnow, Phoxinus phoxinus). The nymphs immediately increased their refuge use when exposed to a live fish, whereas chemical cues alone did not cause any avoidance responses. In a second experiment, the eVects of (1) fish chemicals and (2) a fish model plus fish chemicals on the diel refuge use patterns of Baetis nymphs were examined. In the presence of a fish model, more nymphs…

Life in the ice lane: the winter ecology of stream salmonids

2007

Despite the common view that conditions in winter strongly influence survival and population size of fish, the ecology of salmonids has not been as extensively studied in winter as in other seasons. In this paper, we review the latest studies on salmonid winter survival, habitat use, movement and biotic interactions as they relate to the prevailing physical and habitat conditions in rivers and streams. The majority of research conducted on the winter ecology of salmonids has been carried out in small rivers and streams, where temperatures are above zero and where there is no ice. Investigations in large rivers, regulated and dredged rivers, and under conditions of different ice formations a…

The role of lantern fish (Myctophidae) in the life-cycle of cetacean parasites from western Mediterranean waters

2015

Myctophids (lantern fish) and cephalopods play a key role in trophic webs from the continental slope and oceanic waters linking the zooplankton to top predators. Many cetaceans feed on both lantern fish and cephalopods, and such prey would thus be expected to bridge the trophic gap in the life-cycles of helminths infecting cetaceans. However, information on the life-cycles of most of these helminths is extremely scanty. We examined the parasite fauna of myctophids and cephalopods in two areas from the western Mediterranean where at least 21 helminth taxa from cetaceans have been reported and both cetacean diversity and abundance is high. A total of 1012 individuals of 8 lantern fish species…

Gut Microbiome Analysis In Adult Tropical Gars (Atractosteus tropicus)

2019

AbstractTropical gar (Atractosteus tropicus), is freshwater and estuarine fish that has inhabited the Earth since the Mesozoic era, undergoing limited physiological variation ever since. This omnivorous fish is endemic to southern Mexico and part of Central America. Besides its recognized cultural and scientific relevance, the species has seen remarkable growth in its economic impact due to pisciculture. Previous studies have highlighted the role of microbial communities in fish, particularly those in the gut microbiome, in maintaining their host homeostasis or disease. In this study, we present the first report of the whole taxonomic composition of microbial communities in gut contents of …

The musculature of the electric fish Eigenmannia virescens (South American green knife fish) characterized with cytochrome oxidase staining

1986

Using cytochrome C-oxidase staining, different types of somatic musculature were clearly distinguished in the gymnotoid fish Eigenmannia virescens. Except for a few thin fibres in the region of the horizontal septum, which stained faintly, no others in the trunk muscle stained. Strong staining appeared in the fibres of the anal fin muscles. According to the classification of fish musculature into white, intermediate and red, only the locomotory organ of this fish has red fibres, whereas the trunk muscles are white. The red muscles along the horizontal septum, found in all other fish which have been investigated in this respect, seem to be absent. This is noteworthy since the anal fin alone …

Purification and molecular characterization of the rhamnose binding lectin from sea bass (Dicentrarchus labrax) that agglutinate Gram positive and ne…

2013

Evolution and Immune Function of Fish Lectins

2016

Abstract Lectins are sugar-binding proteins widely distributed among animals, plants, and microbial taxon, involved in diverse biological processes. In both invertebrates and vertebrates, they play key roles in nonself recognition and immune responses, such as nonself recognition, inflammatory processes, and immunomodulation. In fish, many lectin families have been identified, and their tissue-specific expression and localization of the various lectin repertoires and their ligands are consistent with their distinct biological roles in innate and adaptive immunity. Here, we discuss the involvement of F-type lectins, rhamnose-binding lectins, galectins, and C-type lectins in pathogen recognit…

Taimenen mädin säilyvyys ja alkioiden kasvu Savijoen kipsinlevitysalueella

2019

Pelloille tehtävän kipsinlevityksen vesistövaikutuksia tutkittiin Helsingin yliopiston ja Suomen ympäristökeskuksen yhteishankkeessa ”SAVE - Saaristomeren vedenlaadun parantaminen peltojen kipsikäsittelyllä”. Hanke oli ympäristöministeriön rahoittama hallituksen kärkihanke. Siinä missä kipsin, eli kalsiumsulfaatin, levitys on vähentänyt pelloilta tulevaa fosforikuormitusta, se on toisaalta nostanut pilottialuetta halkovan Savijoen sulfaattipitoisuuden kolminkertaiseksi. Suuren sulfaattipitoisuuden tiedetään olevan haitallista vesieliöille, kuten kaloille. Näin ollen Jyväskylän yliopisto selvitti kipsinlevityksen vaikutuksia taimenen (Salmo trutta) varhaisten elinvaiheiden säilyvyyteen ja ka…

Impact Assessment of Skidding Extraction: Effects on Physical and Chemical Properties of Forest Soils and on Maple Seedling Growing along the Skid Tr…

2019

Several studies investigated soil disturbances caused on skid trails by forest logging. However, there is still a lack of knowledge about the severity and the distance of disturbances along both sides from the trails. The aims of this study were: i) to investigate the changes in physical and chemical properties of soil along the sides of skidding trails