Monitoring with Ganglia

Colophon

The animal on the cover of Monitoring with Ganglia is a Porpita pacifica, which is found in the tropical Pacific. P. pacifica, commonly called the sea money or blue button, is a blue-fringed disc about 1.5 inches in diameter. Its delicate tentacles are sticky and extend from chambers in the gas-filled disc; the tentacles are usually damaged in the surf and reportedly deliver a sting that is not powerful but may cause irritation to human skin.

The blue button lives on the surface of the sea and consists of two main parts: the float and the hydroid colony. The hard golden-brown float is round, almost flat, and about 1 inch wide. The hydroid colony, which can range from bright blue turquoise to yellow, resembles tentacles like those of the jellyfish. Each strand has numerous branchlets, each of which ends in knobs of stinging cells called nematocysts.

In the food web, its size makes it easy prey for several organisms. The blue button itself is a passive drifter, meaning that it feeds on both living and dead organisms that come in contact with it. It competes with other drifters for food and mainly feeds on small fish, eggs, and zooplankton. The blue button has a single mouth located beneath the float, which is used for both the intake of nutrients and the expulsion of wastes. This species reproduces by releasing tiny medusa, which go on to develop new colonies.

The cover image is from Beauties and Wonders of Land and Sea. The cover font is Adobe ITC Garamond. The text font is ...