Ascending speed and nocturnal activity of adult masu salmon (Oncorhynchus masou Brevoort) during upstream migration.

We released five adult masu salmon (Oncorhynchus masou) tagged with external transmitters to track their ascending behaviour. The signals of all specimens were recorded in the upper area of the river system. Two patterns of ascending behaviour were recognized: ascending upward immediately after release and ascending during increased river discharge. The fastest ascending speed was about 1000 m h-1 . Active movements were detected at night. The signal recording duration at each receiver for each fish was generally brief. Most fish did not stay at the pools where the receivers were installed.

Inflationary universe with anisotropic hair.

We study an inflationary scenario with a vector field coupled with an inflaton field and show that the inflationary Universe is endowed with anisotropy for a wide range of coupling functions. This anisotropic inflation is a tracking solution where the energy density of the vector field follows that of the inflaton field irrespective of initial conditions. We find a universal relation between the anisotropy and a slow-roll parameter of inflation. Our finding has observational implications and gives a counterexample to the cosmic no-hair conjecture.