Stargazers (Uranoscopidae) have two specialized characters- large volume of bile
and a small-size brain. To explain why stargazers need large volume of bile, two
hypotheses were proposed: (1) a function of the bile of stargazers is acting as the sex
pheromone, and (2) bile enhances calcium uptake efficiency. The brain volume was
measured, and the volumes of each part of the brain were also measured. The
elementary investigations indicate that the stargazers have larger bile volume ratio and
smaller brain weight ratio than other fishes reported in the present studies. The bile
volumes are no significant difference between the female stargazers and the male
stargazers, the bile volumes showed no monthly difference. Besides, the number of
olfactory epithelium and the neuron density of the telencephalon in stargazers were
not more than other fishes, the function of sex pheromone of bile can not be
confirmed. The cranium hardness, bone density, and calcium content in stargazers are
significantly more than other fishes. Most fish uptake calcium by the gill and the
intestine from seawater or food. However, stargazers often hide in the sand and wait
for the prey for most of the time, less water flow through the gills are expected.
Therefore stargazers possibly uptake calcium through the intestine. Efficiency of the
bile to aid calcium uptake has to be examined by experiments. The paraffin histology
has been taken in various parts of the brain. Crista cerebelli is the center for sensing
mechanical vibration; the volume of stargazer¡¦s crista cerebelli is higher than other
fishes. Stargazers have large saccular otolith compare to the whole brain. Studies on
the lateral line and acoustic sense of stargazers are new research topics. Furthermore,
decrease in brain size in stargazers is for the purpose of reducing the oxygen
consumption, so as to hiding in the sand. Stargazers are one of the fisheries species on
western Taiwan coast. However there are very few studies on the stargazers in Taiwan;
we should understand more about them in order to protect and consume the stargazers
in a better way.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0820110-134059 |
| Date | 20 August 2010 |
| Creators | Hsu, Jumg-chen |
| Contributors | Chuan-Chin Chiao, Meng-Hsien Chen, Hin-Kiu Mok |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0820110-134059 |
| Rights | withheld, Copyright information available at source archive |
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