Stellar Biotechnologies, Inc. Releases Semi-Annual President’s Letter to Shareholders

PORT HUENEME, CA--(Marketwire - June 13, 2011) -

Stellar Biotechnologies, Inc. “Stellar” (TSX-V: KLH) (PINKSHEETS: SBOTF) is pleased to announce that its semi-annual CEO Letter to Shareholders has been released.

The June 13, 2011 Letter from the President can be reviewed in full at www.stellarbiotechnologies.com/investors/shareholders/

Highlights - Content Headings

• Grants

• Bayer

• Corporate Milestones Related to Stellar IMG/KLH

• Customer Development

• Business Development Activities

• New Product Launch - First Stage of Pre-Clinical Diagnostic Suite

• Aquaculture

• FDA - Pre-IDE Meeting

• Team & Physical Plant Additions/Changes

• U.S. Stock Listing & Shareholders Rights Plan

• Looking Forward & Open House Invitation

Review full President’s June 13, 2011 Letter to Shareholders at www.stellarbiotechnologies.com/investors/shareholders

About Stellar Biotechnologies, Inc. Stellar Biotechnologies, Inc. (TSX-V: KLH) (PINKSHEETS: SBOTF) (www.StellarBiotechnologies.com) is a world leader in sustainable manufacturing of pharmaceutical grade immune carrier proteins (ICP), particularly with regard to the present most important pharmaceutical protein in this class, KLH (Keyhole LimpetHemocyanin). This evolutionary protein has a highly complex structure that makes it ideal for use in human and animal vaccines and diagnostic products. With partners and customers, its flagship Stellar KLH products are in the clinic, and on the way to being established as the only sustainable, long-term pharmaceutical source. Stellar Biotechnologies was founded to address the urgent need for sustained, commercial-scale supplies of high quality, GMP-grade KLH. Stellar has developed leading practices, facilities and proprietary capabilities to address this need.

There can be no assurance that forward-looking statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Readers should not place undue reliance on such statements. Except in accordance with applicable securities laws, the Company expressly disclaims any obligation to update any forward-looking statements or forward-looking statements that are incorporated by reference herein. This news release does not constitute an offer to sell, or a solicitation of an offer to buy any of the Company’s securities set out herein in the United States, or to, or for the benefit or account of, a U.S. Person or person in the United States. Neither TSX Venture Exchange nor its Regulation Services Provider accepts responsibility for the adequacy or accuracy of these releases.