This to be a form of Thuridilla gracilis. It is possible there is more than one species involved but the different colour patterns seem to merge into one another.
Glossodoris cincta This nudibranch grows up to three inches in length and is known to discharge a white fluid from its mantle when provoked. The beautiful turquoise and yellow margin along the mantle is one of three color schemes known for the species;
Chromodoris quadricolor, which is known from the Red Sea is most similar to C. africana and C. magnifica having three blue-black stripes, separated by white, and a wide orange marginal band. The rhinophores and gills are orange-red.
Red Scorpion FishScorpaenopsis oxycephalus
This member of family Chromodorididae is fairly abundant. As with the other Glossodoris nudibranchs, it has a thick body and swollen, undulating mantle edge -- in this case emphasized with a dark line. This one is about 1 1/2 inches in length.
Red small pteroisDendrochirus brachypterus
Another example of a species belonging to the family Phyllidiidae, characterised by the absence of external dorsal gills and the appearance of wart-like bumps on its mantle. They are also stiff and rubbery in texture compared to most nudibranchs, and move very slowly (even for a nudibranch).
Eel in black sand
Nudibranchs Hypselodoris nigrostriata feeding a Dysidea dark blue spongeHypselodoris nigrostriata
Identified by Bill Rudman :
I am pretty sure this is Hypselodoris nigrostriata, but I find it pretty difficult to distinguish it from H. zephyra. I have made in messages concerning both species I have some doubts about whether we are dealing with one or two species here.
Of more interest is that these two animals are feeding on the dark blue sponge. The oral tube of the animal on the right of your photo is clearly visible. The sponge is almost certainly a species of Dysidea.
Bill Rudman Australian Museum, Sydney
Locality: Lambeh strait, 15 m, Indonesia, North Sulawesi, Indo Pacific, 30 april 2006, muck dive. Length: 50-70 mm.
"I am pretty sure this is Hypselodoris kanga. The spots on the outer face of each gill are not clear but there is a double orange line which indicates the gills are triangular in cross-section. Now and then there are specimens in which the spots are not easy to see." Bill Rudman Australian Museum, Sydney
Locality: Lambeh strait, 15 m, Indonesia, North Sulawesi, Indopacific, 30 april 2006, Muck. Length: 50-70 mm.
"This is Hypselodoris kanga. It can be distinguished from similarly coloured species such as H. infucata by the shape and colour of the gills. If you look carefully, the gills of H. kanga are triangular in cross-section and there are white or yellow spots on the smooth outer edge of each gill. This animal is feeding on the dark blue sponge. The extended oral tube of the animal is clearly visible. The sponge is almost certainly a species of Dysidea". Bill Rudman Australian Museum, Sydney
Locality: Lembeh Strait, Indonesia, Indo pacific, 28 April 2006, muck dive. Length: about 70 mm.
Considerable variation in mantle colour from red to yellow, but in all cases there is a pattern of white spots and rings and a pale blue border. In all specimens the ubderside of the mantle and all the body and foot are bright yellow.
Little shrimp in anemonPericlimenes sp.
Syngnathidae (Pipefishes and seahorses), subfamily: Syngnathinae. Occur in protected coastal shallows over or among algae, seagrasses, or floating weeds. Juveniles occasionally found near the surface. Ovoviviparous. The males carry the eggs in a brood pouch which is found under the tail. Unfortunately used in Chinese medicine to extract Hailong, one of the important drugs.
Porcelain crabs in anemonNeopetrolisthes ohshimai
Anemon fishesAmphiprion ocellaris
The Amphiprion ocellaris clown fish, oval, with large rounded fins, orange colour with 3 white bars, the middle one with a bulge forward. A thin black line separates white and orange. All fins are orange with black edge. 9 cm.
Distribution : From Andaman Sea to Moluccas (Western Pacific).
It lives in obligate symbiosis with few anemone species, in particular with Heteractis magnifica (the more common), Stichodactyla gigantea and S. mertensii.
Xenocrab on whip coralXenocrab
This is the most widespread of the genus. The members of the family display a relatively small shell in respect to the body size and therefore not able to retract into it. This harp is feeding at night.