1. 海豚   sea urchin   lobster   dolphin   mussel   Hint Half-n-half Clue   2. 虾   mussel   shrimp   crab   seal   Half-n-half Clue   3. 箭鱼   oyster   swordfish   jellyfish   seal   Half-n-half Clue   4. 淡菜   shark   seal   shrimp   mussel   Half-n-half Clue   5. 鳗鱼   turtle   otter   eel   starfish   Half-n-half Clue   6. 蜗牛   swordfish   lobster   shark   snail   Half-n-half Clue   7. 螃蟹   octopus   seal   sea urchin   crab   Half-n-half Clue