COMMENTS & OBSERVATIONS

Several days of good weather popped up but discretion saw me avoiding Australia Day nonsense at the ramp and choosing the following day, Friday, instead but it was still very busy. I joined the procession making its way down the Mooloolah River at dawn. The trip across to Mudjimba Island was without swell or chop. Unfortunately the water visibility was low at 3 m but still sufficient for sea slug searching. Some good finds were recorded but what was not sighted was just as interesting. Many of the most usual suspects were not to be seen. A new species to our list, Tritonia sp. 05, was recognized on reviewing the images post-dive.

Taxonomic Diversity:
All 13 of the species sighted were nudibranchs, with 9 being dorids comprising 2 x phanerobranch (non-retractile gill), 1 x porostome (suctorial feeder of the Phyllidiidae family), 6 x cryptobranchs (retractable gill – all belonging to the Chromodorididae family) and 4 x cladobranchs comprising 2 x aeolids, 1 x arminid and 1 x dendronotinid. If diet is considered then 7 of the 13 species sighted are spongivores.

Our Historical Data:
– This excursion brings the number of survey dives to 28 at this site since we commenced fully recording data here on 19/07/2010.
– 130 species have been recorded at this site.
– The most regularly recorded species at this site are: Goniobranchus splendidus (96%), Phyllidiella pustulosa (82%), Doriprismatica atromarginata (79%), and Phyllidia ocellata (79%), however, interestingly, only two of those four were sighted on this excursion.
– Interestingly, Doriprismatica atromarginata, one of the the most commonly recorded species at many of the offshore sites we survey, is not the most commonly recorded here but, when sighted, is the most abundant at around 9 per dive.
– This is the first time we have recorded Tritonia sp. 05 on the Sunshine Coast, therefore being a new addition to our list.
– This is the first time we have recorded Goniobranchus collingwoodi and Kaloplocamus acutus at this site and only the second time we have recorded Dermatobranchus oculus here.
– The line graph shows the relationship between number of sea slug species sighted against total number of sea slug organisms sighted. (see Image Gallery below)
– Although the data is limited (recorded on only 10 occasions here) Glossodoris vespa appears to be more abundant over the summer months of November, December and January (see bar graph in Image Gallery below)
– This site last surveyed on 15/11/2022.
(Historical data courtesy of Terry Farr, who extracts it from his comprehensive database.)

Key to symbols
+++ New Species
+ First time sighted at this site
# Most commonly sighted at this site with %

TOTAL SPECIES SIGHTED: 13

DIVE IMAGES GALLERY

PUT CURSOR ON IMAGE FOR SPECIES NAME
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