The leaf-stirring exercise was so successful that I stirred some more leaves, and out shot several more aquatic-larva-type creatures, but only about half the size of our naiad, and very differently colored.Below, you can see one:Ī shot from a different angle is shown below: In that picture, behind the head, you can see two tiny flaps, which are incipient wings, or wing pads. Moreover, nymphs of dragonflies and damselflies are known by the special name of naiad - the word "naiad" rhyming with "pie ad." This particular naiad was obliging enough to allow the face portrait shown below: With six legs and no wings you might guess that this is an insect larva, and among the insects with big heads, large, widely spaced compound eyes and short, stiff antennae, and who hang around streams, what could this be but the larval stage of a dragonfly or damselfly? And since dragonflies and damselflies undergo incomplete metamorphosis where the larva emerging from the egg resembles a much smaller, wingless edition of the adult, the creature in the photo is a nymph. Below, you can see the bug-eyed little fellow submerged in about half a finger of water:Īfter taking that picture our discovery was coaxed into the palm of my hand, resulting in the picture below: In a shallow pool of the little Dry Frio River, when some blackened sycamore leaves sunken to the pool's bottom were stirred, a creature about ¾inch long (2cm) shot from among the leaves, settled at the pool's edge, grabbing onto a sycamore leaf's petiole. They are more than curiosities macros are intermediaries in the story of a larger ecology where they recycle nutrients and subsequently feed the wildlife that we humans are more likely to notice.PLANTS | ANIMALS | ECOLOGY | FUNGI | GEOLOGY | GARDENING | TOOLSįrom the FebruNewsletter issued from the Frio Canyon Nature Education Center in the valley of the Dry Frio River in northern Uvalde County, southwestern Texas, on the southern border of the Edwards Plateau, USA They carry forest floor resources with them throughout the forest and adjacent waters. Macros are key players in the enrichment of a wet forest. As these organisms are eaten by predators and then, even larger predators the nutrients and energy of the cast‐offs from previous years become the building blocks of a fresh new spring. There are shredders, nibblers, and scrapers with unique appendages and mouth parts that collectively transform dead material into living tissue. Then, the macros come along in many sizes and shapes with an array of skills and appetites. Microscopic algae, fungi and bacteria often initiate the process. To digest these coarse resources a variety of organisms are engaged. It is often said that vernal pools are fueled by detritus, fallen leaves, limbs and other plant materials that fall to the forest floor. Predaceous Diving Beetle Larva, photo by Judy Semroc Many insects, including dragonflies, damselflies, beetles, bugs and flies use this strategy. Other macros only use vernal pools to lay eggs and feed as they grow, but later leave the pool as adults before the waters dry down. Fairy shrimp, that only live in vernal pools, are the premiere example of this strategy. One life‐cycle strategy is to hatch very early, mature, breed and lay eggs that will become dormant until the next season. Many of them become active in winter, even below a layer of ice. Macroinvertebrates are especially suited to life in temporary waters. Others range in size down to the tiniest speck. The largest macros of vernal pools are crayfish and dragonflies that, as adults can grow to more than three inches in length. Those that can be seen without magnification are collectively known as macro‐invertebrates (macros). Vernal pools are populated by dozens, if not hundreds, of small organisms that are not vertebrates, so called because they do not have backbones like frogs and salamanders.
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