Search
Search Results
-
Problems at the Ecosystem Level
To analyze conservation problems at the ecosystem level it is necessary to investigate inter alia problems of changes in their structure,...
-
Compositional patterns in the nuclear genome of cold-blooded vertebrates
DNA preparations obtained from 122 species of fishes, 5 species of amphibians, and 13 species of reptiles were investigated in their compositional...
-
On the ontogeny of the haptor and the evolution of the Monogenea
Data on the ontogeny of the posterior haptor of monogeneans were obtained from more than 150 publications and summarised. These data were plotted...
-
Mechanisms of synthesis and action of 17α,20β-dihydroxy-4-pregnen-3-one, a teleost maturation-inducing substance
This article briefly reviews the current status of investigations, mainly based on the amago salmon, Oncorhynchus rhodurus , on the mechanisms of...
-
A visual pigment of the sturgeon retina
The visual pigments of hybrid sturgeon (a cross between Acipenser ruthenus (male) and Huso huso (female) have been studied both by the methods of...
-
Immunohistochemical investigation of the pituitary of the sturgeon (Acipenser baeri, Chondrostei)
An immunohistochemical study of the sturgeon ( Acipenser baeri ) pituitary was undertaken using antisera directed against hormones from various classes...
-
Re-description of Eubothrium vittevitellatus Mamaev, 1968 (Cestoda: Pseudophyllidea) from sand fish (Trichodon trichodon Tilesius) in Kamchatka Bay with an assessment of its distribution
Eubothrium vittevitellatus is re-described with particular attention being paid to scolex characters seen by scanning electron microscopy in material...
-
The evolution of migration and some life history parameters in marine fishes
Migration is a common phenomenon in marine fishes but the consequences with respect to life history variation have been little explored. Migration...
-
Development of the Mature Egg Organization in Amphibians, Fish, and Starfish During the Concluding Stages of Oogenesis, in the Period of Maturation
During the concluding stages of oogenesis, in the period of maturation, the fully grown oocyte turns into an egg capable of fertilization and further...
-
Meiotic Divisions
Most studies of meiosis devote more attention to the meiotic prophase than to the subsequent phases of both meiotic divisions (“maturation...
-
The Nucleus During Oogenesis with Special Reference to Extrachromosomal Structures
In studies of oocytes the nuclear structure has not only been used for studying oogenesis proper, but also for solving a number of general...
-
Bionomics and Ecology
The Eurasian huchen and beyond doubt the whole genus Hucho may be included in the ecological group of lithophilous, brood-hiding species (group...
-
On the karyosystematics of cyprinid fishes and a summary of fish chromosome studies in China
To date, the chromosomes of 210 species of fresh-water fishes have been studied in China. They are principally cyprinids. Based upon the karyotypic...
-
Tetraploid-octoploid relationships and karyological evolution in the order Acipenseriformes (Pisces) karyotypes, nucleoli, and nucleolus-organizer regions in four acipenserid species
The karyotypes of four Acipenseriformes species, Acipenser gueldenstaedti , 2n=250±8, A. ruthenus, A. stellatus and Huso huso , 2n=118±2, are...
-
Regulation of oocyte maturation in the rainbow trout,Salmo gairdneri: role of cyclic AMP in the mechanism of action of the maturation inducing steroid (MIS), 17α-hydroxy, 20β-dihydroprogesterone
In fish, oocyte maturation (resumption of meiosis after completion of vitellogenesis and before ovulation) is triggered by maturation inducing...
-
Chemoreceptors
In lower vertebrates, especially in fish, the following cells and organs are considered as serving as chemoreceptors: solitary chemosensory cells,...
-
The fishery, biology, and management of Atlantic sturgeon, Acipenser oxyrhynchus, in North America
The Atlantic sturgeon supported major fisheries along the entire Atlantic coast of North America. These fisheries peaked about 1890 and then suffered...
-
Oocyte maturation in white sturgeon, Acipenser transmontanus: some mechanisms and applications
The ovaries of four pre-spawning white sturgeon females were sampled and their oocytes incubated in the presence of eight gonadotropin preparations,...
-
Osmoregulation in juvenile and adult white sturgeon, Acipenser transmontanus
Blood samples from cannulated young adult (2.5–15 kg) white sturgeon, acclimated to San Francisco Bay water (24 ppt) had plasma values of 248.8 ±...