Friday, April 23, 2010

A Dangerous Dance

Although the weather has cooled somewhat, there is a mass of insect life around - in sizes ranging from mosquitoes to dragonflies.
This could be partially due to the massive rains recieved earlier.

Welcome Swallows buzz the nearby dam in flocks approaching fifty in mumber, showing that lavae of all sorts are there for the taking.

Our resident spider species have been taking advantage of this fact also, catching masses of small annoying insects before they gain entry to our home.

There has even been a little time for them to do one of the most dangerous dances of all for a spider - the act of mating.
These two are engaged in that dance.
"Palps" of the male spider, the smaller of the two in the foreground, place sperm into openings in the female while, at least with this species, they face to face as though locked in some mortal combat.
The female spider often eats the male after mating, and sometimes during the act, dependant on the species and how quick the male can make a run for it afterwards.
A danerous dance indeed.

Wednesday, April 07, 2010

Port Jackson Sharks

This strange form is the egg case from the Port Jackson Shark.
It forms this twisted spiraling shape once dried.
The juvenile shark escapes from the far end, leaving an opening in the top

I found a number of them on Blenheim Beach (Marine Bay), located near Jarvis Bay area within the marine park.
Pictured with the fine white sand as a backdrop below

The area is located just south of Nowra on the south coast of NSW, Australia.
A map of the surrounds, and the area visited shown here.

The beach has a small creek running to it, with temperate coastal rainforest at its fringes.

The Marine Park was established some time ago, as the area was recognized as a significant bio-diverse region warranting protection.

Along with the casings found, a number of sea slugs were found nearby amongst sea weed and a dragonfly nymph located in the fresh water of the creek within 25 meters of the surf.
While we enjoyed the surf, a pod of dolphins cruised close by.
A very pleasant and diverse place indeed.

Tuesday, April 06, 2010

Adaptation of Design

Arachnids never cease to amaze me.
I photographed this orb spiders web the other day with a strange adaptation.

The center of the web is inline with the wire, thus giving the spider some cover from the prying eyes of predators.
In case you might feel this has a degree of chance involved, the web is fixed to the wire only at the center point, with the rest of the intersection floating freely so as to catch prey.
This design would offer both protection and stability of the web.
An example of evolution at work through design adaptation.