Friday, July 24, 2009

Echinoderms - SEA-STARS & SEA-URCHINS


































Tosia   labelled wrongly is the same genus but this one is not  biscuit sea star (very similar)













Biscuit Seastar.






The Eight-armed sea-star is very common all around Victoria's coast. There is a great deal of variation in colour. One rock pool can have a number of different colour variations in it. The next few pics shows some of the variations.












































































This picture and the two below show something very unusual in the world of sea-urchins. This Victorian urchin exhibits parental care. Look closely at this top photo and you can see two juvenile urchins safely lodged in the arms of the parent. The tiny urchins develop on their mothers shell between the spines. While the parent carries these young it apparantly supplies nutriment to the young from its outer shell. The next photos show the underside ( the mouth of the urchin is in the middle where the there are no visible spines). Most of the young (there were about 10 - 12) were situated here.










This urchin is one found in deepeer water. It is not likely to be in a rockpool or washed up on the beach.

Thursday, July 23, 2009

Cnidarians- Sea Anemones and Sea Jellies of Victoria

Coral, Sea anemones and Sea jellies, at first may not seem that similar but they are very closely related and collectively known as Cnidarians (the C is silent). Victoria's temperate waters do not have corals like there are in the tropics of Qld and WA. Occasionally a small piece of dead hard coral is washed onto the beach which is the remains of one of the few corals that can cope with cold water.
This is live coral from waters off Victoria.


Tailed Sea-jelly, Vic.


Brown Blubber jelly, Vic.



Upside down sea jelly, Vic.



Vic


The circular areas on the top are the reproductive organs(gonads) of the jelly.












Swan Bay, Queenscliff, Vic


Upside down sea jelly, Vic.

Comb jelly


Lions' mane Jelly (above and below) Vic.











This may look like little bits of shell grit but it is actually a sea anemone that uses these bits for protection and camouflage. Taken at low tide when it is exposed to air for some time untill the tide comes back in.