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短棘鰏(Leiognathus equulus)為台灣沿近海重要的經濟性魚種，本研究在臺灣西南海域使用三個袋網網目，其規格分別為：86 mm、75 mm、15 mm進行網目選擇性試驗。計漁獲短棘鰏4,924尾，體長分布為86.8 mm〜233.7 mm間。75 mm目大袋網可保留約98％之短棘鰏漁獲重量；86mm目大袋網可保留約67％之漁獲重量。75 mm網目則可完全漁獲體長135 mm以上之短棘鰏個體。利用logistic曲線推估目大86 mm之短棘鰏50％選擇體長(L50％)為120.61 mm，選擇指距(selection span)為30.90 mm，選擇係數(selection factor)為1.6。由以上結果考量短棘鰏之最小性成熟體長顯示，臺灣西南海域底拖網漁業現行20 mm以下之袋網網目應逐步擴大至100 mm，如此將可避免漁獲未成熟短棘鰏，並可減少下雜魚之混獲比例。 花斑蛇鯔係台灣西南海域最主要經濟性魚類之一，本研究所使用之材料，係於民國97年5月至98年5月，按月至屏東縣東港區漁會魚市場採集，而這些標本係由當地之小型單拖網船所漁獲，共計採得標本1,319尾。花斑蛇鯔之性比為53.4%，。一般上，雌性魚之體型比雄型魚大，而在主要產卵群的中大型魚亦以雌性魚佔極大優勢。花斑蛇鯔在生殖其間，卵徑達0.5mm，此時生殖腺即發育至成熟狀態，花斑蛇鯔週年產卵，盛產卵期在1～4月，屬於生殖期長而多次產卵型。花斑蛇鯔之平均總孕卵數為72,2636 ±188,490粒，總孕卵數與卵巢重之間呈指數型的關係，其曲線迴歸關係式為T=15721OW+32968， r=0.942。平均產卵數為72,397 ±65,643粒，卵粒平均成熟率約為31.0%，相對孕卵數為8,460～267,720粒，平均為27,429粒。花斑蛇鯔之最小性成熟體長，初步判定雌性魚為173.3 mm，雄性魚為152.5 mm。 在中層拖網部份，就2009年11月至2010年5月漁期間，正櫻蝦標本船作業2,256網次之漁況、魚市場之卸貨量與產值，及2009年11月至2010年5月期間，共採集雌蝦2,973尾，雄蝦989尾，計3,962尾等之資料，進行漁獲狀況及生物特性之解析。結果顯示本年度每網次平均作業時間為1.84小時，CPUE為每網次37.49公斤。漁獲組成中，正櫻蝦佔24.81 ％，燈籠魚科佔60.34 ％，其它魚蝦類佔14.85 ％。魚市場之卸貨量為941.82公噸，產值為新台幣27,733萬元。漁場生產力指數平均較高之海域於枋寮至枋山海域及東港外海海域。正櫻蝦之性比月別變化介於65.10～89.33%，其中以1月最高，2月最低。成熟雌蝦比例介於2.99～40.06%，其中以3月最高，12月最低。雌蝦之體長分佈範圍為21.5～49.8mm，平均體長33.2mm，雄蝦之體長分佈範圍為22.5～41.9mm，平均體長32.3mm。在體長(BL)與體重(BW)之關係上，雌蝦為BW=6x10-4BL1.7439，r=0.567，雄蝦為BW=1.3x10-3BL1.4714，r=0.453。

研究報告摘要(英) Leiognathus equulus, is an important economical species in the coastal waters of Taiwan. We use three mesh sizes 86, 75 and 15 mm to mesh selectivity study in southwestern of Taiwan . 4924 individuals of Leiognathus equulus were caught. The fork lengths were between 86.8 and 233.7 mm. The mesh size of 75 mm could retain about 98% of weight , the 86 mm was 67% . For Leiognathus equulus, the fork lengths above 135 mm were retained by 75 mm mesh size. Mesh selectivity using logistic regression indicated that 50% selection lengths (L50％) of the mesh sizes 86 for Leiognathus equulus was 120.61mm, the selection spans (SP) was 30.90 mm, and the selection factors (SF) was 1.6. According to the size of first maturity of Leiognathus equulus, the present mesh size of small trawl which was 20 mm should be regulated to 100 mm. The regulation of mesh size of small trawl could release unripe Leiognathus equulus, and reduce bycatch for the purposes of resources conservation and improve the economic income. The Brushtooth lizardfish, Saurida undosquamis, is one of the important commercial species for the trawl fishery in southwestern Taiwan. Its reproductive biology was described based on 1,319 specimens collected between May 2008 and May 2009 caught by small trawlers in southwestern Taiwan waters. Sex ratio of female to male is 1:1.3, showing a predominance of the male. The body size of female is larger than of male. Oocytes were mature when they attained 0.5 mm The mean fecundity was estimated to be 72,2636 ±188,490 and fecundity (F) was found to increase exponentially with ovary weight (OW) F=15721OW+32968， r=0.942. The mean batch fecundity was estimated to be 72,397 ±65,643, and relative fecundity ranged from 8,460 to 267,720 (mean 27,429) per gram body weight. Size at 50% first maturity was estimated to be 173.3 mm and 152.5 mm FL for females and males, respectively. A multi-spawning pattern was observed on the Brushtooth lizardfish; it spawns throughout the year with a peak in January to April. This report included the analysis on the fishing condition based on the catch statistics collected from 16 sampling vessels and fish market during the period from November 2009 to May 2010. Meanwhile, the analysis on the biological characters of sergestid shrimp based on the sampling data was conducted during the period from November 2009 to May 2010. The average fishing time was 1.84 hours with a CPUE of 37.49 kg per net haul. The species composition included sergestid shrimp (24.81%), myctophid fishes (60.34%), and the other fishes (14.85%). The landing of sergestid shrimp in the fish market was 941.82 mt with a value of 27,733 ten thousand N.T. dollars. The productivity in the coastal area off Fan-Shan was higher than the coastal area off Tung-Kang. The monthly ratio of female shrimp was between 65.10% and 89.33% with a peak in Jeanuary. The length-weight regression equations of the female and male shrimp were calculated as BW=6x10-4BL1.7439，r=0.567 for female, and BW=1.3x10-3BL1.4714，r=0.453 for male.