Posts Tagged ‘Polyorchis penicillatus’

A preponderance of plankton

October 2, 2014


As I was leaving the floating building at 12:15 pm yesterday (1 October 2014), I noticed a golf ball-sized green blob floating past the Pearson College dock. It turned out to be this red-eye jellyfish (Polyorchis penicillatus) and right next to it was a sea gooseberry or ctenophore (Pleurobrachia bachei) and a barnacle moult.


The bell of the jellyfish is covered in a green algae and the red eyespots are visible around the margin of the bell and there is a red amphipod living in association with the jellyfish too (see it peeking out from the margin of the jelly in the two photos below).



And here is a better view of the comb jelly / ctenophore Pleurobrachia bachei which we rarely see around the Pearson College dock, but is periodically very common at the Race Rocks jetty.


Simon and I also met several students at the dock last night at 8:30 pm to observe bioluminescence. It was magical! While moving our hands through the water we saw a line of bioluminescence about 6 cm long which turned out to be a cross jellyfish (Mitrocoma cellularia) which “luminesces if disturbed in the dark, especially in a band along the margin of the bell” according to Cowles (2009).

Pedder Bay water has turned to chocolate (& jelly)!

June 21, 2012

For the past several days the water in Pedder Bay has been the colour of milk chocolate:

The visibility is very poor as seen in the photos above and below.

Brown, brown water!

In the photos below, the jar on the left contains tap water while the jar on the right contains water collected off the Pearson College docks at 12:30 pm today by filling the jar from the surface water.

The brown colour of the water is actually not chocolate, but is in fact due to an abundance of  an as yet unidentified plankton species. Below are photos taken through a compound microscope:

Amongst the many, many little ciliates that were zipping around the field of view, there were a few Parafavella sp. (the little champagne glasses), a dinoflagellate species (Peridinium perhaps?) and the occasional rotifer (one even had eggs).  The sample was clearly dominated by the brown coloured ciliate, however.  If you have any idea about the species (based on these terrible photos or from experience with the ciliates of Pedder Bay), please help with the identification!!

In addition to the microscopic organisms, there has been an abundance of small (1-1.5 cm) Polyorchis penicillatus jellies around the Pearson College docks.

Sorry about the terrible quality of the photos!  For more information on Polyorchis penicillatus (and a much better photo!) see the page from the Monterey Bay Aquarium.