. The Australian zoologist. Zoology; Zoology; Zoology. 48 TIIF. MIGRATION OF THF, OR EFX-GUDGEON, GdloXiaS attetlUatUS. Two barriers of cheesecloth were fastened across the stream, being placed so that tliev allowed the water to pass through, but blocked the passage of fish either up or down stream. When first arranged in position both barriers were wholly in fresh water, and a careful search for hall an hour failed to discover any fish above, below, or between them ; the conditions for searching were particu- larly good, the water being quite clear and running over white sand, a
. The Australian zoologist. Zoology; Zoology; Zoology. 48 TIIF. MIGRATION OF THF, OR EFX-GUDGEON, GdloXiaS attetlUatUS. Two barriers of cheesecloth were fastened across the stream, being placed so that tliev allowed the water to pass through, but blocked the passage of fish either up or down stream. When first arranged in position both barriers were wholly in fresh water, and a careful search for hall an hour failed to discover any fish above, below, or between them ; the conditions for searching were particu- larly good, the water being quite clear and running over white sand, and we could hardly have tailed to find the fish had they been present. After hall an hour the tide rose sufficiently to send an extra big wave over the lower barrier(d) and we immediatelj afterwards secured a fish above it ; successive waves produced further specimens until the lower barrier was destroyed. While we «en- getting fish at the lower barrier, the upper one (i) was also carefully watched, but we failed to find any fish above it; after tin- lower one was destroyed, however, we found several specimens directly below the barrier (6) and swimming stoutly against the strong current of the stream passing through it. This test was carefully and successfully carried out, and seems to leave no doubt that the fish entered the stream through the surf from the sea, and were making their way upstream. We have, therefore, to assume that they had been bred in the sea. where they had undergone their earlier development; they had possibly been carried far from the place of their birth l>v the currenl extending along the coast; ami, finally, they must have been remarkably sensitive to the presence of fresh water to discover so small a stream as that in which they were found. There have been several records of other species of Galaxias occurring in the sea, and it appears I ml able that (/. truttaceus is not confined to fresh water ; it occurs in both Victoria and Tasmani I and I h
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectzoology, bookyear1914
