Why here, does the Torah write that Hashem said to them "P'ru u'Revu", whereas above (in Pasuk 22) with regard to the fish, it did not?
Ramban: Whereas above, He merely blessed the animals with the ability to increase, here He is conferring upon Adam and Chavah a blessing that they succeed in doing so.
Why does the Torah split the Berachah in two?
Rashi (in Teshuvos): The initial Berachah extends to all the animals as well, and Hashem added a Berachah to Adam and Chavah that they should rule over all the other creatures.
Targum Yonasan: He learns like Rashi, but interprets "and fill the earth" with reference to amassing property.
What was Hashem's command "and fill the earth"?
Ramban #1: He was instructing Adam and Chavah here to try their utmost to have as many children as possible.
Ramban #2: He was ordering them to fill the world, and not to remain in one place as the generation of the Tower planned to do.
Why does the Torah omit the second 'Vav' in the word "v'Chivshuha" (and conquer (rule) over it)?
Rashi #1: This refers (not to ruling 'over' it' (the animal world) but 'over her' (Chavah); it teaches us that a man will keep his wife in check, to prevent her from leaving the house ("Every honorable princess dwells within" [Tehilim 45:14]). 1
Rashi #2: This teaches us that a man, whose way it is to conquer, has the Mitzvah of Peru u'Rvu, but a woman.
What is the difference between "v'Chivshuhah" and "u'Redu"?
Seforno: "v'Chivshuhah" - Control the wild animals (by means of your superior knowledge) from entering your domain; "u'Redu - catch them with nets and traps to use them for your own benefit. In similar vein, the Ramban explains that man will be able to utilize everything in the world, including the animals, to his advantage, even the fish and the birds (and the wild beasts), which will not be so easy to catch.
רש"י: שהזכר כובש את הנקבה...ועוד...שהאיש...מצווה על פריה ורביה: לכאורה נחלקו בגמ' כיצד לפרש את הפסוק?
גור אריה: ביבמות נחלקו האם נשים מצוות בפריה ורביה. חכמים שפטרו נשים דרשו מ'וכבשה' שרק האיש מצווה, אבל יש לומר שאין זה פשוטו של מקרא ולכן הוסיף רש"י שגם רבנן דרשו שהזכר לכובשה.
גור אריה: את הפירוש הראשון כתב רש"י לפי דעת ר' יוחנן בן ברוקא שנשים אינן מצוות על פריה ורביה ואת הפרוש השני לחכמים שרק האיש מצווה.