COMMENTS & OBSERVATIONS

It was a Sunday, but the weather was too good to ignore, so the fun and games at the ramp was endured to take advantage of possibly the last day of offshore diving for at least a week. Dawn found Li’l Mischief on the Outer Gneerings however there was a strong southerly current of 2 knots plus, flowing over the shoals. After waiting for half an hour to see if it would abate I pulled anchor and headed back in to the Trench site on the Inner Gneerings. Here the water was a little green rather than blue but there was no current to contend with.  On the first dive twenty-seven specimens across thirteen species were recorded with the little Diversidoris sp. 01 making a good subject and so too the mating pair of Cadlinella ornatissima. The surface interval was interesting with another dive boat trying to move in on to the same dive site without communication of any sort. The second dive was even more rewarding, the Verconia laboutei the highlight.

Taxonomic Diversity:
24 of the 25 species sighted were nudibranchs, with 21 being dorids comprising 4 x phanerobranch (non-retractile gill), 6 x porostome (suctorial feeders – all of the Phyllidiidae family), 11 x cryptobranchs (retractable gill – all belonging to the Chromodorididae family) and 3 x cladobranchs comprising 2 x aeolids, 1 x arminid. A single sacoglossan rounds out the species numbers. If diet is considered then 19 of the 25 species sighted are spongivores.

Our Historical Data:
– This excursion brings the number of survey dives to 36 at this site since we commenced fully recording data here on 10/07/2010.
– 131 species have been recorded at this site.
– The most regularly recorded species at this site are: Doriprismatica atromarginata (97%), Phyllidiella pustulosa (97%), Thuridilla cf. splendens (83%) and Chromodoris elisabethina (78%).
– This is the first time we have recorded Verconia laboutei and Phyllidia guamensis at this site and only the second time we have recorded Chromodoris lochi, Cratena simba, Diversidoris sp. 01, Hypselodoris tryoni  (the latter two recorded twice on surveys on the same day), and Miamira magnifica 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)
– This site last surveyed on 19/01/2023.
(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: 25

DIVE IMAGES GALLERY

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