碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 98 / Blackspotted gurnard (Pterygotrigla hemisticta) is a species of Triglidae in the order Scorpaeniformes. It is one of the demersal fishes in the coastal waters off Taiwan. In order to realize the reproductive features of this species, a total of 1,300 specimens (742 females and 558 males) were sampled by otter trawl monthly between Oct. 2008 and Sep. 2009 in Dasi fishing port, Yilan. The mean sex ratio was 57.1%. The sex ratio had significantly difference between sexes based on Chi-square test. The test showed that the sex ratio of the specimens < 16 cm TL was significantly < 50%, but was female fish dominated when length classes > 30cm TL. The relationship between body weight (BW; in g) and total length (TL; in cm) showed that the P. hemisticta had nosignificant difference between females (BW = 0.0172TL 2.9173 ) and males (BW = 0.0264TL2.7653 ). The oocyte development could be divided into Chromatin-nucleolus stage, Peri-nucleolus stage, Yolk vesicle stage, pre-yolk stage, post-yolk stage, Migratory nucleus stage, Ripe egg stage, Reproduction stage and Atretic oocytes stage by the histological examination and ovarian development measurements. We also found that P. hemisticta reached its maturity when the gonadosomtic index (GSI) > 3. P. hemisticta asynchronous and a batch fertility spawner based on the following five techniques: macroscopic appearance of ovarian stage, histological examination of ovaries, oocyte diameter measurements, GSI, and monthly percentage in each maturity stage. The spawning season of P. hemisticta in the coastal waters of Taiwan was estimated all round year, with a peak from Jan. to June. The fecundity of this species ranged from 23,773 to 249,370 eggs, with a mean of 119,936 ± 942 eggs. Batch fecundity of this species ranged from 1,124 to 13,407 eggs, with a mean of 4,862 ± 46 eggs. The relationship between fecundity (F) and body weight (g) was F = 0.44BW + 11.38 (r2 = 0.8252, n = 34). Both fecundity and batch fecundity increased with the total length, body weight, and gonad weight. Length at maturity was estimated to be 17.86 cm TL and 16.09 cm TL for females and males, respectively based on the relationship between proportion of maturity and total length.
| Identifer | oai:union.ndltd.org:TW/098NTOU5451010 |
| Date | January 2010 |
| Creators | Li-Ling Kao, 高麗玲 |
| Contributors | Shoou Jeng Joung, 莊守正 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 101 |
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