Although there are a number of reports concerning the uptake of various radioactive nuclides from surrounding water by aquatic organisms1), the quantitative informations on the transfer of radioactive substances through aquatic food chains have been scarcely obtained until now. In near future, in accordance with the rapid developement of the peaceful utilization of atomic energy in Japan, the p...

In aquatic environments, endocrine disrupting chemicals (EDCs) that interfere with the reproductive physiology of males form a threat to the reproduction of populations. This is often manifested as decreased sexual performance or sterility among males. We show that exposure to EDCs can directly affect the mating system of a marine fish, the sand goby (Pomatoschistus minutus). We exposed males f...

Predation risk is high for the many small coral reef fishes, requiring successful sheltering or other predator defence mechanisms. Coral-dwelling gobies of the genus Gobiodon live in close association with scleractinian corals of the genus Acropora. Earlier studies indicated that the low movement frequency of adult fishes and the development of skin toxins (crinotoxicity) are predation avoidanc...

—Fish larvae were sampled at multiple fixed sites from late winter to early summer over 6 years (1990–1995) in the southern Sacramento–San Joaquin Delta. A total of 394,797 fish larvae representing 15 species or taxonomic groups was collected. The assemblage was numerically dominated by three species that represented 98% of the total catch: alien shimofuri goby Tridentiger bifasciatus (71%), th...

UNLABELLED The amount of ultraviolet (UV) radiation reaching the earth's surface has increased due to depletion of the ozone layer. Several studies have reported that UV radiation reduces survival of fish larvae. However, indirect and sub-lethal impacts of UV radiation on fish behavior have been given little consideration. We observed the escape performance of larval cod (24 dph, SL: 7.6±0.2 mm...

Gonadotropin-releasing hormone (GnRH) is widely distributed in the brain of fishes where it may function as a neuromodulator of sensory processing and behavior. Immunocytochemical and neuronal label experiments were conducted on species from four families of coral reef fishes (Chaetodontidae, butterflyfish; Pomacentridae, damselfish; Gobiidae, goby; and Labridae, wrasse) to assess conservation ...

We investigated the degree of flexibility in retention strategies of young fishes in the low-salinity zone (LSZ) of the San Francisco Estuary during years of highly variable river flow. We conducted depth-stratified sampling over three full tidal cycles in each year from 1994 to 1996. In 1994, exotic striped bass (Morone saxatilis), native longfin smelt (Spirinchus thaleichthys), and exotic yel...