九孔(Haliotis diversicolor)自1980 年代開始即是台灣重要的漁業與養殖物種。根據農委會統計在2001年台灣曾締造全球最大產量的紀錄。但在此後的11 年產量急遽下降97%。漁業署曾組成專案調查小組研擬解決對策，認為死因是多個因子造成；冬天過低的水溫可能是九孔暴斃的引爆點。傳統選拔與雜交育種已證明可提高貝類海水養殖的生產量；瞭解九孔遺傳多樣性與辨識地方族群的方法將有助於族群整體性狀的改善。本研究將以分子標記、種內雜交及選拔育種、估算遺傳參數、利用雜交育種及雜種優勢和基因型與環境的互作等方面進行九孔育種的研究。主要將研究：1、九孔群體的歧化選擇及選擇效應、採用歧化選擇法對兩個九孔群體的殼長進行雙向選擇。2、九孔生長性狀遺傳力的估算、3、九孔形態性狀的遺傳相關、4、探討九孔的不同地理群體間雜交及雜種優勢、5、九孔的基因型與環境互作研究。進行九孔種質資源評估，為遺傳選育提供基本數據，為下一步九孔全基因組的遺傳育種研究打基礎。 Small abalone (Haliotis diversicolor) is commercially important for both fisheries and aquaculture in Taiwan since1980s. According to the Taiwan Council of Agriculture, in 2001 Taiwan had the biggest abalone production in the world.However, the production of small abalone has dramatically fallen more than 97 percent in last 11 years. A series ofinvestigations was conducted after the mortality event and indicated no single causative factor could explain themortalities. The mortality event was often associated with the onset of winter and the low water temperatures, and it ispossible that this was the final stressor that initiated the event. According to the official report published by TaiwanCouncil of Agriculture, Taiwan stock suffers a tremendous disease breakout in recent years. Understanding its geneticdiversity and developing stock identification methods will be extremely useful for stock improvement. Selection and hybridizationas the traditional way have also proved effective in the genetic improvement of mariculture mollusks. Quantitativegenetics and breeding of small abalone will be used to study the selective breeding and estimation of genetic parameters,crossbreeding among different geographically populations and genotype ×environment interaction. We will focus themain researches on： 1. Divergent selection for shell length in two stocks of small abalone, 2. Heritability of growth traitsestimated from sib matings, 3. Genetic correlations on morphological traits of small abalone, 4. Growth and survival ofthree best populations and their reciprocal crosses, and 5. Check the genotype × environment interaction.