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Dive Reports

23-05-2024 Grays Bay

DAY/DATE

Thursday

23/05/2024

SITE/S

Grays Bay

Bowen

 

PARTICIPANTS

Julie & Terry

 

TYPE

Subtidal

 

MODE

Shore Entry

 

VESSEL

 

DIVE

1

 

SITE/S

Grays Bay

 

SPECIES #

4

 

DURATION

126 Min

 

DEPTH/RANGE

3 m

 

TEMP.

22 C

 

VIS.

2 m

 

SURGE

Nil

 

CURRENT

Nil

 

COMMENTS & OBSERVATIONS

Preferring low visibility over surge we jumped in at Grays Bay in nice flat conditions. We descended sooner than normal and headed out but encountered unfamiliar rocks instead of corals. The reef is rather narrow close to shore so after ascending to check whether to go east or west, I descended back down to the mighty depths of 2m to find Terry with a couple of Plakobranchus ocellatus. We continued to scour this area for a while longer and ended up counting 14 of these critters in a relatively small area. Eventually we headed out along the reef and found a few different species including a tiny Niparaya sp. The Gymnodoris sp. we encountered does not appear to match any of the species we have recorded so far. Back in the shallows on our return I located another tiny critter, this one being an Atys which was intent on burying in the sand and covering itself in slime, making a positive ID difficult.

This is one of our most productive dives at this site.

Taxonomic Diversity:
Two of the four species sighted were nudibranchs, both being dorids comprising 1 x phanerobranch (non-retractile gill), 0 x porostomes (suctorial feeder),  1 x cryptobranch (retractable gill). 1 x sacoglossan and 1 x cephalaspidean complete the species count. If diet is considered only 1 of the 4 species sighted was a spongivore.

Our Historical data:
– We have now completed 8 surveys and recorded 17 species at Grays Bay since our first survey here on 26/04/2023.
– Our most frequently recorded species here are Doriprismatica atromarginata (50%), Hypselodoris roo (38%), Plakobranchus ocellatus (38%), and Chromodoris lineolata (43%);
– This is the first time we have recorded Gymnodoris sp. 33 in Australia. This species appears to be similar to the Gymnodoris sp. 47 in Gosliner et al. (2018:81)
– This is the first time we have recorded Niparaya sp. 10 in Australia. This species appears to be similar to the Niparaya sp. 1 in Gosliner et al. (2018:366), which the authors reported was found “crawling in sea water tanks at the Christensen Research Institute, feeding on small flatworms”. The species we recorded was found on silty substrate at around 2.5 m depth .
– Our last survey at this site was on 24/04/2024.
(Historical data courtesy of Terry Farr, who extracts it from his comprehensive database.)

Reference:
Gosliner, T. M., Valde ́s, A ́. & Behrens, D. W. (2018). Nudibranch & Sea Slug Identification – Indo-Pacific, 2nd Edition. New World Publications, Jacksonville, Florida, USA.


Guide to Symbols:
+++ New Species
+ First time sighted in Whitsundays
# Most commonly sighted at this site with %

TOTAL SPECIES SIGHTED: 4

 

SPECIES LIST – ALPHABETICAL

Doriprismatica atromarginata -2 #50%
Gymnodoris sp. 33 -1 +++ 
Niparaya sp. 10 -1 +++ 
Plakobranchus ocellatus -14 #38%

SPECIES GROUPED BY ORDER

Nudibranchia
Dorids
Phanerobranchs
Gymnodoris sp. 33 -1
 Cryptobranchs
Doriprismatica atromarginata -2
Porostomes

Cladobranchs
Aeolids

Arminids

Dendronotinids

Cephalaspidea
Niparaya sp. 10 -1

Sacoglossa
Plakobranchus ocellatus -14

Umbraculoidea

Pleurobranchoidea

Anaspidea

DIVE IMAGES GALLERY

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