Practical Perforce

Colophon

Our look is the result of reader comments, our own experimentation, and feedback from distribution channels. Distinctive covers complement our distinctive approach to technical topics, breathing personality and life into potentially dry subjects.

The animals on the cover of Practical Perforce are herring, of which there are over 200 species. In particular, the Atlantic herring (Clupea harengus) lives in the coastal waters off New England and can be found from Nova Scotia to Cape Cod.

Atlantic herring begin their lives as larvae measuring five to seven millimeters long. They emerge from an egg bed that can contain as many as seven million eggs. Tiny, scaleless, and transparent, they are weak swimmers and rely on a yolk sack for nourishment after hatching. Soon after the yolk is used up, they develop mouth parts that enable them to eat such prey as tiny plankton and the eggs and larvae of clams, shrimp, and barnacles.

The larval stage can last from 3 to 11 months (usually 6 months) depending on environmental factors such as water temperature and scarcity of food. Of the millions of eggs deposited by herring each year, it is estimated that only one percent will survive to be juvenile herring or “brits.”

Usually around spring, the larvae grow into brits that look like smaller herring. Silvery blue-green scales begin to form, and their bodies grow thicker and flatter, measuring about 40 millimeters in length. At this time, the brits begin to form schools that migrate shoreward ...