DAY/DATE
Wednesday
01/03/2023
SITE/S
Trench
Inner Gneerings
PARTICIPANTS
David
TYPE
Subtidal
MODE
Boat Dives
VESSEL
Li’l Mischief
DIVE
1
2
SITE/S
Trench
Trench
SPECIES #
13
14
DURATION
67 Min
63 Min
DEPTH/RANGE
14-18 m
14-18 m
TEMP.
26 C
26 C
VIS.
8 m
8 m
SURGE
Nil
Nil
CURRENT
Nil
Nil
COMMENTS & OBSERVATIONS
A busy mid-week morning at the La Balsa Park boat ramp. Just after dawn found Li’l Mischief anchored at the Trench dive site. The anchor lay in 18 m of water so I checked its position and then started to head up the drop off to search the plateau in 14 m of water in order to extend my bottom time. On the way up I noticed a very small speck of yellow on the substrate which turned out to be a 5 mm specimen of a new species of Verconia for our list (Verconia sp. 06 = Verconia sp. 5 of NSSI-ii). It presented with a single rhinophore that appeared to be the result of a developmental error rather than a predator’s attack. Roughly equal species numbers sighted on each dive. Ardeadoris egretta was a nice find, and very photogenic too, being recorded at this site over the past couple of months, but I was fortunate to come across two specimens. The number of Chromodoris elisabethina specimens is staying high in comparison to other species at this site.
Taxonomic Diversity:
22 of the 23 species sighted were nudibranchs, with 17 being dorids comprising 2 x phanerobranch (non-retractile gill), 4 x porostome (suctorial feeders – all of the Phyllidiidae family), 11 x cryptobranchs (retractable gill – all except one belonging to the Chromodorididae family) and 3 x cladobranchs comprising 3 x aeolids, 1 x arminid and 1 x dendronotinid. A single sacoglossan rounds out the species numbers. If diet is considered then 15 of the 23 species sighted are spongivores.
Our Historical Data:
– This excursion brings the number of survey dives to 38 at this site since we commenced fully recording data here on 10/07/2010.
– 134 species have been recorded at this site.
– The most regularly recorded species at this site are: Doriprismatica atromarginata (97%), Phyllidiella pustulosa (95%), Thuridilla cf. splendens (82%) and Chromodoris elisabethina (79%).
– This is the first time we have recorded Verconia sp. 06 on the Sunshine Coast.
– This is the first time we have recorded Ardeadoris egretta or Cratena lineata at this site and only the second time we have recorded Goniobranchus albonares or Gymnodoris alba here.
– The bar graphs show a possible seasonal pattern to the seasonal abundance of Doriprismatica atromarginata and Goniobranchus splendidus at this site. (See Image Gallery below)
– This site last surveyed on 29/01/2023.
(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: 23
SPECIES LIST – ALPHABETICAL
Ardeadoris egretta 2/-
Bornella anguilla -/1
Bulbaeolidia alba -/1
Chromodoris elisabethina 5/5 #79%
Chromodoris kuiteri 3/1
Cratena lineata -/1
Cratena simba 1/-
Dermatobranchus rodmani -/1
Doriprismatica atromarginata 1/1 #97%
Glossodoris rufomarginata -/2
Glossodoris vespa 1/-
Goniobranchus albonares -/1
Goniobranchus splendidus 1/-
Gymnodoris alba -/1
Hypselodoris jacksoni 1/-
Jorunna sp. 03 -/1
Phyllidia elegans 1/-
Phyllidia varicosa 1/-
Phyllidiella lizae 1/1
Phyllidiella pustulosa -/4 #95%
Roboastra luteolineata 1/-
Thuridilla cf. splendens -/2 #82%
Verconia sp. 06 1/- +++
SPECIES GROUPED BY ORDER
Nudibranchia
Dorids
Phanerobranchs
Gymnodoris alba -/1
Roboastra luteolineata 1/-
Cryptobranchs
Ardeadoris egretta 2/-
Chromodoris elisabethina 5/5
Chromodoris kuiteri 3/1
Doriprismatica atromarginata 1/1
Glossodoris rufomarginata -/2
Glossodoris vespa 1/-
Goniobranchus albonares -/1
Goniobranchus splendidus 1/-
Hypselodoris jacksoni 1/-
Jorunna sp. 03 -/1
Verconia sp. 06 1/- +++
Porostomes
Phyllidia elegans 1/-
Phyllidia varicosa 1/-
Phyllidiella lizae 1/1
Phyllidiella pustulosa -/4
Cladobranchs
Aeolids
Bulbaeolidia alba -/1
Cratena lineata -/1
Cratena simba 1/-
Arminids
Dermatobranchus rodmani -/1
Dendronotinids
Bornella anguilla -/1
Cephalaspidea
–
Pteropoda
–
Sacoglossa
– Thuridilla cf. splendens -/2
Umbraculoidea
–
Pleurobranchoidea
–
Anaspidea
–