[Edit]
AKB48 had a total of 140 members during all their 11 generations. the first until the third generation is what we know as the original teams (1st Gen: Team A, 2nd Gen: Team K, 3rd Gen: Team B).
Later on when more auditions were held, all the future successful candidates would take part of a in-training team of members that would work as sub and under for the official members in various actives (mostly the Theater Performances). and finally, when any of the official members would graduate a girl would be promoted to fill the space.
this group of girls was called AKB48 SEED. A term was was dropped later on and changed for Kenkyusei Members (Research Students). after more auditions and eventually more generations were created, the Kenkyuseis started to perform by themselves in the theater covering various old AKB48 Stages.
in 2009 a Team Kenkyusei (Previously they were just "Kenkyusei(s)" and not part of any kind of team) was created and different "auditions" were periodically made before a new Generation joined the group. all the current Kenkyuseis went through a selection phase where the manager decided which girls "truly wanted" to be an idol and were actually giving their best. eventually, some girls were Demoted during each Kenkyusei Sellection to reduce the quantity of members (these girls were always given the chance to audition once again and start from zero. thing that actually happened with some members, and some even made it to be part of the group once again.)
since then, the Team Kenkyusei are considered and acknowledged as another team of the group and currently even perform in the theater way more frequently than the "official" teams.
they also started to appear in the singles (even as Senbatsu) and also got their own tv show focused in them. denoting the importance they have even though they any of them have a real safe position in the group.
Some AKB48 Members actually auditioned more than once until being finally successful joining the group (like the current Team B captain, Kashiwagi Yuki). some even auditioned and were transfered to the spin-off groups (graduated Kenkyusei Deguchi Aki and previous Kenkyusei Nakanishi Yuka are now part of SKE48).
As of February 2011, AKB48 has 57 Members and 14 Kenkyusei Members with members from the 10th and 11th generation.
Team A
* Iwasa Misaki (わさみん Wasamin)
* Oota Aika (らぶたん Rabutan/Lovetan)
* Oya Shizuka (しいちゃん Shiichan)
* Katayama Haruka (はーちゃん Haachan)
* Kuramochi Asuka (もっちぃ Mocchi)
* Kojima Haruna (こじはる Kojiharu, はるにゃん Harunyan)
* Sashihara Rino (さっしー Sasshi)
* Shinoda Mariko (麻里子さん Mariko-sama, まりりん Maririn)
* Takajo Aki (あきちゃ Akicha)
* Takahashi Minami (たかみな Takamina) (Captain)
* Nakagawa Haruka (はるごん Harugon)
* Nakata Chisato (ちぃちゃん Chiichan)
* Nakaya Sayaka (なかやん Nakayan)
* Maeda Ami (あーみん Aamin)
* Maeda Atsuko (あっちゃん Acchan)
* Matsubara Natsumi (なっつみぃ Nattsumii)
Team K
* Akimoto Sayaka (さやか Sayaka)
* Itano Tomomi (ともちん Tomochin)
* Uchida Mayumi (ウッチー Ucchii)
* Umeda Ayaka (うめちゃん Umechan)
* Oshima Yuko (ゆうこ Yuuko)
* Kikuchi Ayaka (あやりん Ayarin)
* Tanabe Miku (たなみん Tanamin)
* Nakatsuka Tomomi (ともちゃん Tomochan)
* Nito Moeno (もえの Moeno)
* Nonaka Misato (みちゃ Micha)
* Fujie Reina (れいにゃん Reinyan)
* Matsui Sakiko (咲子 Sakiko)
* Minegishi Minami (みいちゃん Miichan)
* Miyazawa Sae (さえ Sae)
* Yokoyama Yui (ゆい Yui)
* Yonezawa Rumi (よねちゃん Yonechan)
Team B
* Ishida Haruka (はるきゃん Harukyan)
* Oku Manami (まぁちゃん Maachan)
* Kasai Tomomi (とも〜み Tomo~mi)
* Kitahara Rie (きたりえ Kitarie)
* Kashiwagi Yuki (ゆきりん Yukirin) (Captain)
* Kobayashi Kana (かな Kana)
* Komori Mika (こもりん Komorin)
* Sato Amina (あみな Amina)
* Sato Sumire (すーちゃん Suuchan)
* Sato Natsuki (Nなっち Nacchi)
* Suzuki Mariya (まりやんぬ Mariyannu)
* Chikano Rina (チカリーナ Chikariina)
* Hirajima Natsumi (なっちゃん Nacchan)
* Masuda Yuka (ゆか Yuka)
* Miyazaki Miho (みゃお Myao)
* Watanabe Mayu (まゆゆ Mayuyu)