Such Precocious Youngsters!

From July 26, 1991 (update #9)

BUFFALO, N.Y. -- Sexually mature zebra mussels as small as 0.2 inches (4.5 mm) long were reported by U.S. Fish & Wildlife researcher Susan J. Nichols at the recent annual meeting here of the International Association for Great Lakes Research (IAGLR). Although Nichols observed maximum growth rates last year of 0.008 inches (0.21 mm) per day, she said that growth rates this year may be even higher. This suggests that, under ideal conditions, zebra mussels may be able to produce many generations within a single season. Nichols has also observed small proportions (10%-20%) of the mussel population carrying ripe gametes in January and February, indicating that reproduction could begin as soon as conditions become right. Reproduction near Monroe, Mich., began this year around May 12; settlement of post-veligers was first observed in that area six weeks later.

ID: 19910726-14.

The Zebra Mussel Update was a 4- to 8-page quarterly national newsletter published by the University of Wisconsin Sea Grant Institute from May 1990 through May 1997. The ZMU documented the spread of the zebra mussel -- an exotic nuisance mussel -- through North America's freshwater environments, especially the Great Lakes, and on efforts to control it.