Image source: Ciena Corporation

What: Shares of Ciena Corporation (CIEN 1.42%) were down more than 18% as of 11:30 a.m. EST Thursday after the network specialist announced mixed fiscal first quarter 2016 results.

So what: Quarterly revenue rose 8.3% year over year to $573.1 million, or slightly below analysts' consensus estimates for $576.3 million. That translated to a GAAP net loss of $11.5 million, or $0.08 per share, narrowed from a $0.17-per-share GAAP net loss in the same year-ago period. On an adjusted (non-GAAP) basis, Ciena's gross margin came in at 44.7%, and adjusted operating margin was 8.3%. Adjusted net income was $25.2 million, or $0.18 per share, up from adjusted net income of $13.6 million, or $0.12 per share in last year's fiscal first quarter. In this case, Wall Street was anticipating lower adjusted net income of $0.14 per share.

Cienna CEO Gary Smith insisted Ciena's financial performance during The quarter was "strong," and "highlighted by engagement with a more diverse set of customers."

Now what: "Despite some recent volatility in the broader macroeconomic environment," Smith elaborated, "the demand drivers for our business remain firmly in place and we are well positioned to translate our market leadership into continued growth and profitability this fiscal year."

Nonetheless, for the current fiscal second quarter 2016, Ciena expects revenue of $615 million to $645 million, with adjusted gross margin remaining steady in the mid-40% range. By comparison, analysts' consensus called fiscal Q2 revenue at the high end of Ciena's guidance range.

In the end, while this certainly shouldn't alarm long-term shareholders as Ciena remains solidly profitably and its growth story remains intact, it's no surprise to see the market bidding Ciena stock down Thursday given the company's continued near-term weakness.