Monday, October 31, 2016

Researchers test morphometric method to determine sex of Japanese eels

 
Japanese eel (Anguilla japonica) is a commercially important aquaculture species in Eastern Asia, including Japan, Taiwan, Eastern China, Korea and Vietnam. However, most of the eels supplied by the aquaculture industry are grown from wild glass eels. Therefore, to fulfill the demand for glass eels in aquaculture artificial breeding is essential to conserve wild eel populations.
At the silvering stage, female eels are usually longer than males, but in the yellow eel stage, it is difficult to predict the sex of eels because of their long slender body shape.
At the Aquaculture Europe conference held last fall in Rotterdam, Netherlands H.M.V. Udayantha and colleagues Yucheol Kim, Thanthrige Thiunuwan Priyathilaka, Hyung-Bok Jeong, Jehee Lee, Shinkwon Kim, and Bong-Soo Lim from the School of Marine Biomedical Sciences, Jeju National University, Republic of Korea, described an easy morphometric method to determine the sex of Japanese eels.
To facilitate the process 180 Japanese eels from an eel farm in Younggwang, South Korea, were separated into two groups according to their body length (301-400 mm and 401-500 mm) and the following measurements were made: total length (TL); fin to fin length (FFL); fin height (FH); and fin length (FL). From these, the total length-to-fin width ratio (TL/FW) and total length to fin height ratio (TL/FH) were calculated for each eel. Body and gonad weights were measured to calculate the gonado-somatic index (GSI), and histological investigation to confirm their sex.
Total length-to-fin width ratios were calculated for eels in each group. In both cases females showed significantly higher TL/FW ratio than males. In the 301-400.mm group the female ratio was more than 31 while the ratio for males was lower than 31. In the other length group (401-500 mm) the females ratio was above 28, while that of males was less than 28.
Histological observations confirmed the sex of the each of the sampled eels. GSI of all sampled female and male eels were less than ≥ 0.22 and ≥ 0.17 respectively, confirming that the eels were in the yellow eel stage. The authors suggest that the TL/FW ratio can be used reliably for sex determination of yellow-stage Japanese eels.

Wednesday, October 12, 2016

2017年日本水產概算要求草案


日本水產廳日前在執政黨自民黨召開的水產部會中,就2016年度追加預算、2017年度水產相關預算概算要求草案及2019年度水產相關稅制修正草案等進行說明,而該部會最後決定將該等案件提送黨的政務調查會審查。

 草案編列的2017年度預算要求金額為2,060億5,500萬日圓,係2016年度1,783億7,600萬日圓的115.5%。


洪聖銘,摘譯自日刊水產經濟新聞,29 August 2016

Wednesday, October 05, 2016

鰻魚交易是否受限,今後三年將是關鍵

國際產經:日本鰻魚交易是否受限,今後三年將是關鍵

財訊新聞 2016/10/03 10:00
  
財訊快報/劉敏夫】共同社報導指出,正在南非約翰尼斯堡舉行的《華盛頓公約》締約國大會,最快將於4日批准調查全球鰻魚交易實際情況,並探討保護措施的決議案。
根據調查結果,日本鰻魚或將成為限制交易的對象。預定3年後召開的下屆大會將是關鍵。對日本而言,具有實際效果的保護和對非法捕撈等不透明交易採取措施,是當務之急。
9月25日的締約國大會第一委員會會議上,提出決議案的歐盟(EU)在說明理由時主張,有證據表示,鰻魚非法交易在歐洲和亞洲仍在繼續。
歐盟指出,歐洲鰻魚2009年被寫入交易需經出口國批准的《華盛頓公約》附錄二並採取禁運措施後,資源量得到恢復;但另一方面,美國鰻魚等其他品種交易量的增加令人擔憂,呼籲為保護所有品種,多方面收集數據不可或缺。
日本的不安因素在於可能被指出從不進行捕撈的香港大量進口養殖所需鰻苗等,存在交易途徑不透明的問題。早稻田大學客座講師真田康弘提出警告表示,非法交易也存在有組織犯罪的一面,國際社會或將投來嚴厲的目光。他強調,不僅是水產廳,應該包括警察、海上保安廳和環境省,整個日本共同採取措施。
日本正與中國、台灣及韓國推動保護措施,包括把投入養殖池的鰻苗數量減少2成等。真田就此表示,為什麼是2成缺乏科學依據。3年後的委員會建議將有可能發展為限制日本鰻魚交易的提案。


(http://ww2.money-link.com.tw/RealtimeNews/NewsContent.aspx?SN=954578002&PU=0010)

Saturday, October 01, 2016

找一找 , 誰在抓鰻魚?


找一找 , 誰在抓鰻魚?



























尼德蘭箴言(荷蘭語:Nederlandse Spreekwoorden)又譯作「尼德蘭諺語」、「荷蘭諺語」,是法蘭德斯畫家彼得.布勒哲爾 (Pieter Brueghel the Older)1559年創作的一幅油彩畫,畫中描繪了大量的當時在尼德蘭地區流行的諺語,很多現在仍然在使用。
彼得.布勒哲爾 的畫作一向以人類的荒謬愚蠢為題材,而這幅畫的原題是「藍色披風」 (de Blue Cloak) 或「世界的愚蠢」(de Dwaasheid Van de Wereld),表明彼得.布勒哲爾的用意不只是歌頌荷蘭諺語文化,還想籍此描寫人類的愚蠢。原畫以油彩繪畫在橡木板上,畫中描繪了112個可識別的成語或諺語,當中有些諺語不能確定是否真是彼得.布勒哲爾 原本想表達的。

Can we ‘grab the eel by the tail’, however difficult that may seem?