碩士 / 國立清華大學 / 生命科學系 / 86 / The thesis reports on three-years field study and records of
the upstream migration behaviors and recruiting variation of
gobies fry resources by the Ami''s conventional fishing means,
the triangle-shape hand-nets and fish traps. In the study, we
record 9 genus, 11 species of Gobiidae, including two newly
recorded species Schismatogobius ampluvinculus and S. roxasi.
The high tide periods are the only windows available for goby
fries to enter the Hsuikuluan River from the Pacific Ocean.
Moreover the recruiting population fluctuates along with lunar
rhythm. Some suspected major factors that cause the phenomenon
are as followed: geological restriction at the river mouth,
spawning frequency and marine phase of the fishes. Goby fries
are diurnally active and are estimated to migrate upstream
approximately a kilometer per day. The results of capture-
recapture method indicate that the efficiency of the fish trap
is between 0.52~0.28, and that the total amounts of Sicyopterus
japonicus and Rhinogobius gigas are 544~1011 ten thousand and
2058~3822 ten thousand, separately. In contrast, the other
species only contribute to considerably a very tiny proportion.
Total harvesting in the first fish trap weighs 1069.5kg in 1996
and 669.3kg in 1997. The higher gain in 1996 mainly resulted
from the application of the twin fish traps at the same time.
Early life histories of most species captured are constructed by
their otoliths microstructure and microchemistry. Comparing
life histories of these two dominant species shows that they
avoid inter-species competition by using temporally alternative
marine habitats and by taking different bait in streams. These
differences make they occupying distinct ecological niches. S.
japonicus survives the barren fall and winter by lengthy marine
stage with slower growth rate and R. gigas swiftly completes its
short zooplantonic phase in the ocean, thereby these two species
recruit into freshwater ecosystem together in the highly
reproductive spring and summer .
| Identifer | oai:union.ndltd.org:TW/086NTHU0105030 |
| Date | January 1998 |
| Creators | Shiao, Jen-Chieh, 蕭仁傑 |
| Contributors | Chyng-Shyan Tzeng, 曾晴賢 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 1 |
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