Sunday, August 5, 2007

Aphids on Gecko Toes with Tubeworm

This aphid was gingerly picking its way across some gecko toes when it spotted a feather duster tubeworm and stopped for some refreshment.

Photos of aphid, gecko toes and tubeworm taken through the SEM (Scanning Electron Microscope)

Aphid

Aphids are insects that are parasites on the roots, leaves, and stems of plants. Aphids have a proboscis which contains four sharp stylets which is used to pierce plant tissue and suck out the nutritive juices. Horn-shaped tubes at the rear end of the aphid are called cornicles, and they secrete a waxy substance. Aphids also secrete a sweet substance called honeydew, and some kinds of ants actually hide and keep aphids to "farm" them for this "candy".

Gecko Toes

Geckos are small lizards, found mainly in tropical areas. They are the only lizards that make sounds, often a chirping or clicking noise.

Geckos are often welcomed in houses in Hawaii as they eat termites, mosquitos, ants, cockroaches, and moths. Residents may notice that geckos might stake out territories, and so there will be the front window gecko, the kitchen sink gecko, the bathroom gecko, and so on.

Some species of geckos can cling to vertical surfaces, like walls and wondows, because of the disk-shaped toepads which are covered with tiny brushlike projections which create intermolecular friction on surfaces. This micrograph shows these projections. These microscopic hairs create one of the strongest adhesive forces in nature - a fat gecko could support its entire weight with just one toe!

Tubeworm

This is a feather-duster tubeworm. Tubeworms are polychaetes, marine worms that secrete a hard mineral substance or a horny material or glue sand grains together.

Fan worms or feather duster worms are common on rocky shorelines. They stick tentacles on their heads out of their tubes to catch food. They can quickly withdraw into their tubes when threatened, protecting them from most predators.

Polychaetes are related to earthworms.

No comments: