How many animals of each species did moses take with him in the ark.

None. He just took two tablets of stone. The one who took animals on his Ark was Noah:


1) "The Ark of the Covenant (ארון הברית in Hebrew: aron hab'rit) is described in the Bible as a sacred container, wherein rested the Tablets of stone containing the Ten Commandments as well as other sacred Israelite pieces. According to the Biblical account, the Ark was built at the command of God, in accord with Moses' prophetic vision on Mount Sinai (Exodus 25:9-10). God communicated with Moses "from between the two cherubim" on the Ark's cover (Exodus 25:22). The Ark and its sanctuary were "the beauty of Israel" (Lamentations 2:1). Rashi and some Midrashim suggest that there were two arks - a temporary one made by Moses, and a later one made by Bezalel (Hertz 1936)

The Biblical account relates that during the trip of the Israelites, the Ark was carried by the priests ~2,000 cubits (Numbers 35:5; Joshua 4:5) in advance of the people and their army or host (Num. 4:5-6; 10:33-36; Psalms 68:1; 132:8). When the Ark was borne by priests into the bed of the Jordan, the river was separated, opening a pathway for the whole of the host to pass over (Josh. 3:15-16; 4:7-18). The Ark was borne in a seven day procession around the wall of Jericho by three priests sounding seven trumpets of rams' horns, the city taken with a shout (Josh. 6:4-20). When carried, the Ark was always wrapped in a veil, in tachash skins (the identity of this animal is uncertain), and a blue cloth, and was carefully concealed, even from the eyes of the Levites who carried it."
Source and further information:
http://en.wikipedia.org/wiki/Ark_of_the_Covenant


2) "Noah's Ark was, according to Abrahamic religions, a large vessel built at God's command to save Noah, his family, and a core stock of the world's animals from the Great Flood. The story is told in chapters 6-9 of the book of Genesis, with later variations in the Qur'an and a number of other sources."
Source and further information:
http://en.wikipedia.org/wiki/Noah%27s_Ark