Tuesday, July 15, 2014

Species List: La Balsa Park, Mooloolah River, Mooloolaba, Sunshine Coast, 10-07-2014

10 species sighted at La Balsa Park, Mooloolah River, Mooloolaba, Sunshine Coast.

Julie, Terry, and David on this single shore entry night dive of 101 minutes in depths to 5.5m. 6m viz and 19C water temp.

We returned to the river following a hiatus of several weeks in the hope of finding some more "gems" amongst the silt and silt-covered growths on the river bed and we were not disappointed. Three new species have been added to our list and a new size record for Pleurobranchus peronii at 80mm. The aeolids Unidentia angelvaldesi and Pteraeolidia ianthina continue to dominate the count. The Tamanovalva sp. 1 (a bi-valved sacoglossan) is a juvenile however the protoconch (larval shell) is very prominent on the apex of the left shell being characteristic of the genus. It appears very similar to Tamanovalva babai but being very juvenile (the "rhinophores" aren't yet fully developed) and somewhat out of the known distribution this can only be conjecture. The Trinchesia sp. 24 were found on the very shallow sand spit at our exit point in the last couple minutes of our dive probably feeding on the small opportunistic athecate hydroids growing there.  They react very aggressively with a startle response when aggravated by quickly raising and spreading their cerata towards the perceived threat. The third of our new additions presented more of a problem but we are of the belief that it is different to both our existing undescribed Lomanotus - sp. 1 & sp. 2 with both light and dark coloured forms represented in the same colony.

Number of species sighted
* Species with highest specimen count

Facelina sp. 3 - 1
Goniobranchus daphne - 2
Hypselodoris obscura - 1
Lomanotus sp. 3 - 10 (New species)
Pleurobranchus peronii - 1
Pteraeolidia ianthina - 10
Tamanovalva sp. 1 - 1 (New species)
Trinchesia sibogae - 4
Trinchesia sp. 24 - 2 (New species)
* Unidentia angelvaldesi - 11

Pteraeolidia ianthina

Hypselodoris obscura

Unidentia angelvaldesi

Trinchesia sibogae

Pleurobranchus peronii - 80 mm 

Goniobranchus daphne

Facelina sp. 3 - in situ

Facelina sp. 3 - under the microscope

Lomanotus sp. 3 - (New species) 
- on its hydroid (with 9 others)

Lomanotus sp. 3 - (New species) 
- under the microscope 
- darker form

Lomanotus sp. 3 - (New species) 
- under the microscope 
- lighter form

Tamanovalva sp. 1 - Juvenile (New species) 
- note prominent protoconch on left shell

Trinchesia sp. 24 (New species) - on the sand

Trinchesia sp. 24 (New species) 
- under the microscope

Trinchesia sp. 24 (New species) 
- under the microscope 
- exhibiting startle response