UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  SCHEDULE 13G


                    Under the Securities Exchange Act of 1934

                            Harvard Bioscience, Inc.
                                (Name of Issuer)

                     Common Stock, $0.01 par value per share
                         (Title of Class of Securities)

                                    416906105
                                 (CUSIP Number)

                                  April 1, 2008
             (Date of Event Which Requires Filing of this Statement)


     Check the appropriate box to designate the rule pursuant to which this
Schedule is filed:
     [ ]  Rule 13d-1(b)
     [X]  Rule 13d-1(c)
     [ ]  Rule 13d-1(d)





----------------
     *The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which would
alter the disclosures provided in a prior cover page.

     The information required in the remainder of this cover page shall not be
deemed to be "filed" for purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).


                               Page 1 of 11 Pages





CUSIP No. 416906105                   13G                   Page 2 of 11 Pages


--------------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS

            Highbridge International LLC
--------------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
            (see instructions)
                                                                   (a) [X]
                                                                   (b) [ ]
--------------------------------------------------------------------------------
     (3)    SEC USE ONLY
--------------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION

            Cayman Islands, British West Indies
--------------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         -----------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    2,634,333 shares of Common Stock
OWNED BY       -----------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      -----------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,634,333 shares of Common Stock
--------------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            2,634,333 shares of Common Stock
--------------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions)
                                                                       [ ]
--------------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
            8.80%
--------------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON (see instructions)
            OO
--------------------------------------------------------------------------------





CUSIP No. 416906105                   13G                   Page 3 of 11 Pages


--------------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS

            Highbridge Capital Management, LLC
--------------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
            (see instructions)
                                                                   (a) [X]
                                                                   (b) [ ]
--------------------------------------------------------------------------------
     (3)    SEC USE ONLY
--------------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION

            State of Delaware
--------------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         -----------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    2,634,333 shares of Common Stock
OWNED BY       -----------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      -----------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,634,333 shares of Common Stock
--------------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            2,634,333 shares of Common Stock
--------------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions)
                                                                       [ ]
--------------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
            8.80%
--------------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON (see instructions)
            OO
--------------------------------------------------------------------------------





CUSIP No. 416906105                   13G                   Page 4 of 11 Pages


--------------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS

            Glenn Dubin
--------------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
            (see instructions)
                                                                   (a) [X]
                                                                   (b) [ ]
--------------------------------------------------------------------------------
     (3)    SEC USE ONLY
--------------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION

            United States
--------------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         -----------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    2,634,333 shares of Common Stock
OWNED BY       -----------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      -----------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,634,333 shares of Common Stock
--------------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            2,634,333 shares of Common Stock
--------------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions)
                                                                       [ ]
--------------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
            8.80%
--------------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON (see instructions)
            IN
--------------------------------------------------------------------------------





CUSIP No. 416906105                   13G                   Page 5 of 11 Pages


--------------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS

            Henry Swieca
--------------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
            (see instructions)
                                                                   (a) [X]
                                                                   (b) [ ]
--------------------------------------------------------------------------------
     (3)    SEC USE ONLY
--------------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION

            United States
--------------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         -----------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    2,634,333 shares of Common Stock
OWNED BY       -----------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      -----------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,634,333 shares of Common Stock
--------------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            2,634,333 shares of Common Stock
--------------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES (see instructions)
                                                                       [ ]
--------------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
            8.80%
--------------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON (see instructions)
            IN
--------------------------------------------------------------------------------





CUSIP No. 416906105                   13G                   Page 6 of 11 Pages

Item 1.

(a)  Name of Issuer

       Harvard Bioscience, Inc. (the "Company")

(b)  Address of Issuer's Principal Executive Offices
       84 October Hill Road
       Holliston, Massachusetts 01746


Item 2(a).  Name of Person Filing
Item 2(b).  Address of Principal Business Office
Item 2(c).  Citizenship


       HIGHBRIDGE INTERNATIONAL LLC
       c/o Harmonic Fund Services
       The Cayman Corporate Centre, 4th Floor
       27 Hospital Road
       Grand Cayman, Cayman Islands, British West Indies
       Citizenship:  Cayman Islands, British West Indies

       HIGHBRIDGE CAPITAL MANAGEMENT, LLC
       9 West 57th Street, 27th Floor
       New York, New York  10019
       Citizenship:  State of Delaware

       GLENN DUBIN
       c/o Highbridge Capital Management, LLC
       9 West 57th Street, 27th Floor
       New York, New York 10019
       Citizenship:  United States

       HENRY SWIECA
       c/o Highbridge Capital Management, LLC
       9 West 57th Street, 27th Floor
       New York, New York 10019
       Citizenship:  United States


Item 2(d)  Title of Class of Securities

       Common Stock, $0.01 par value per share ("Common Stock")

Item 2(e)  CUSIP Number

       416906105


Item 3. If this statement is filed pursuant to Rules 13d-1(b), or 13d-2(b) or
 (c), check whether the person filing is a:

(a) [ ] Broker or dealer registered under Section 15 of the Act (15 U.S.C.
    78o).

(b) [ ] Bank as defined in Section 3(a)(6) of the Act (15 U.S.C. 78c).





CUSIP No. 416906105                   13G                   Page 7 of 11 Pages


(c) [ ] Insurance company as defined in Section 3(a)(19) of the Act
        (15 U.S.C. 78c).

(d) [ ] Investment company registered under Section 8 of the Investment
        Company Act of 1940 (15 U.S.C. 80a-8).

(e) [ ] An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

(f) [ ] An employee benefit plan or endowment fund in accordance with
        Rule 13d-1(b)(1)(ii)(F);

(g) [ ] A parent holding company or control person in accordance with
        Rule 13d-1(b)(1)(ii)(G);

(h) [ ] A savings association as defined in Section 3(b) of the Federal
        Deposit Insurance Act (12 U.S.C. 1813);

(i) [ ] A church plan that is excluded from the definition of an investment
        company under Section 3(c)(14) of the Investment Company Act of 1940
        (15 U.S.C. 80a-3);

(j) [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

If this statement is filed pursuant to Rule 13d-1(c), check this box. [X]


Item 4.   Ownership

       Provide the following information regarding the aggregate number and
percentage of the class of securities of the issuer identified in Item 1.

       (a)  Amount beneficially owned:

       As of the date of this filing, (i) Highbridge International LLC
beneficially owns 2,634,333 shares of Common Stock and (ii) each of Highbridge
Capital Management, LLC, Glenn Dubin and Henry Swieca may be deemed the
beneficial owner of the 2,634,333 shares of Common Stock beneficially owned by
Highbridge International LLC.

       Highbridge Capital Management, LLC is the trading manager of Highbridge
International LLC. Glenn Dubin is the Chief Executive Officer of Highbridge
Capital Management, LLC. Henry Swieca is the Chief Investment Officer of
Highbridge Capital Management, LLC. The foregoing should not be construed in and
of itself as an admission by any Reporting Person as to beneficial ownership of
shares of Common Stock owned by another Reporting Person. In addition, each of
Highbridge Capital Management, LLC, Glenn Dubin and Henry Swieca disclaims
beneficial ownership of shares of Common Stock held by Highbridge International
LLC.

       (b)  Percent of class:

       The Company's annual report for the fiscal year ended December 31, 2008
filed on Form 10-K on March 11, 1009, indicates that as of February 27, 2009,
there were 29,934,869 shares of Common Stock outstanding. Therefore, based on
the Company's outstanding shares of Common Stock (i) Highbridge International
LLC may be deemed to beneficially own 8.80% of the outstanding shares of Common
Stock of the Company and (ii) each of Highbridge Capital Management, LLC, Glenn





CUSIP No. 416906105                   13G                   Page 8 of 11 Pages


Dubin and Henry Swieca may be deemed to beneficially own 8.80% of the
outstanding shares of Common Stock of the Company. The foregoing should not be
construed in and of itself as an admission by any Reporting Person as to
beneficial ownership of shares of Common Stock owned by another Reporting
Person.

       (c)  Number of shares as to which such person has:

            (i)   Sole power to vote or to direct the vote

                  0

            (ii)  Shared power to vote or to direct the vote

                  See Item 4(a)

            (iii) Sole power to dispose or to direct the disposition of

                  0

            (iv)  Shared power to dispose or to direct the disposition of

                  See Item 4(a)


Item 5.  Ownership of Five Percent or Less of a Class

       Not applicable.


Item 6.  Ownership of More than Five Percent on Behalf of Another Person

       Not applicable.


Item  7.   Identification and Classification of the Subsidiary Which Acquired
           the Security Being Reported on by the Parent Holding Company or
           Control Person

       Not applicable.


Item 8.  Identification and Classification of Members of the Group

       See Exhibit I.


Item 9.  Notice of Dissolution of Group

       Not applicable.


Item 10. Certification

       By signing below each of the undersigned certifies that, to the best of
its knowledge and belief, the securities referred to above were not acquired and





CUSIP No. 416906105                   13G                   Page 9 of 11 Pages


are not held for the purpose of or with the effect of changing or
influencing the control of the issuer of the securities and were not acquired
and are not held in connection with or as a participant in any transaction
having that purpose or effect.


Exhibits:

Exhibit I: Joint Filing Agreement, dated as of April 13, 2009, by and among
Highbridge International LLC, Highbridge Capital Management, LLC, Glenn Dubin
and Henry Swieca.

















CUSIP No. 416906105                   13G                   Page 10 of 11 Pages


                                   SIGNATURES

       After reasonable inquiry and to the best of its knowledge and belief,
each of the undersigned certifies that the information with respect to it set
forth in this statement is true, complete, and correct.

Dated: April 13, 2009


HIGHBRIDGE CAPITAL MANAGEMENT, LLC       HIGHBRIDGE INTERNATIONAL LLC

                                         By: Highbridge Capital Management, LLC
                                             its Trading Manager

By: /s/ John Oliva
------------------------------
Name: John Oliva                         By: /s/ John Oliva
Title: Managing Director                 ----------------------------------
                                         Name: John Oliva
                                         Title: Managing Director



/s/ Henry Swieca                         /s/ Glenn Dubin
------------------------------           ----------------------------------
HENRY SWIECA                             GLENN DUBIN






CUSIP No. 416906105                   13G                   Page 11 of 11 Pages


                                    EXHIBIT I

                             JOINT FILING AGREEMENT

This will confirm the agreement by and among the undersigned that the Schedule
13G filed with the Securities and Exchange Commission on or about the date
hereof with respect to the beneficial ownership by the undersigned of the shares
of Common Stock, $0.01 par value per share, of Harvard Bioscience, Inc., is
being filed, and all amendments thereto will be filed, on behalf of each of the
persons and entities named below in accordance with Rule 13d-1(k) under the
Securities Exchange Act of 1934, as amended. This Agreement may be executed in
two or more counterparts, each of which shall be deemed an original, but all of
which together shall constitute one and the same instrument.

Dated as of April 13, 2009


HIGHBRIDGE CAPITAL MANAGEMENT, LLC       HIGHBRIDGE INTERNATIONAL LLC

                                         By: Highbridge Capital Management, LLC
                                             its Trading Manager

By: /s/ John Oliva
------------------------------
Name: John Oliva                         By: /s/ John Oliva
Title: Managing Director                 ----------------------------------
                                         Name: John Oliva
                                         Title: Managing Director



/s/ Henry Swieca                         /s/ Glenn Dubin
------------------------------           ----------------------------------
HENRY SWIECA                             GLENN DUBIN