Sandy Reef Slopes of the Red Sea:

    These are regions of tapering slope that immediately follow the base of the reef slopes that make up the vast majority of the coasts and island borders of the Red Sea, generally abruptly sloping at the end of the rocky reef slope by a few tens of degrees. They're characterized by a mix of sandy patches of mainly mixed fine (1 mm.) and coarser carbonaceous materials randomly broken up with rock and coral bommies of varying size, most not more than a foot or two in elevation. In the few rare areas where sandy beaches occur, the flora and fauna can be strikingly different (e.g. seagrasses) than these post-shore slopes. 

    Most sandy reef slope areas gently (ten percent or less) grade into an area of more rapid drop-offs within a hundred feet or so of width. Being in depths principally of ten to thirty meters in depth, these sandy reef slopes receive a few to one percent of incidental insolation (sunlight). Currents can be slack to one, two knot/h, though not as pronounced at the reef/water interface.

About Sandy Red Sea Reef Slopes:  Make-Up, Features of Aquarium Importance

     Lower light and water movement conditions work fine for displays incorporating these biotopes. A mix of calcium carbonate substrate sizes is preferable, particularly when incorporating burrowing, sand-dwelling life. 

Biota of the Sandy Reef Slopes of the Red Sea:

    Here we will list and describe the species of most use and availability to aquarists. Of course there are many more species than can be practically detailed here and some species that should not be offered to the hobby do make their way into markets. As a precautionary measure we'll include a table of ones that are often for sale, but shouldn't be due to historically dismal survival records. 

Seagrasses. For the true aficionado and aquarist looking for a challenge, two species of seagrasses occur here in shallow, sandy areas. Of macrophyte algae Sargassum and Turbinaria (Shown) are commonly found, with some scattered Reds and Greens occurring in occasional mainly fist-size or smaller clumps.
Xeniids, Pulsing Corals, and how! These are the dominant element of the landscape, almost covering any available hard surface not otherwise colonized.
Acroporids (Staghorn Corals), family Acroporidae. Dominate what little hard, true coral populations exist here on rocky patch reef areas or seemingly arise on their own pedestals as with acroporids termed Table Corals.
Fire Coral, Millepora spp. Here, more crustose varieties show up, along with large interbranching, planar colonies. Deeper (30 meter) image showing the equally dominant Xeniid species fighting for space with Millepora.
Giant Clams, Tridacna maxima, T. squamosa and T. crocea occur here in this order of preponderance, and shown below. Do select only tank bred and reared specimens. These are hardier, more disease free, and save making "empty spaces" in the wild.

Gobies of various sorts; Shrimp Gobies of the genera Amblyeleotris, Cryptocentrus, Istigobius and Vanderhorstia and their mutualistic Alpheid (Pistol) Shrimp partners are abundant, as are Amblygobius and Valenciennea Sand Sifters and sand dwelling Gnatholepis. For the very sharp-eyed, there are Gobiodon gobies setting in and under Acropora table corals and teeny-tiny Eviota (E. sebreei at right), Trimma and host gobies of the genera Bryaninops and Pleurosicya. The only goby from the area regularly offered in our interest is Amblygobius hectori.
Lionfishes, family Scorpaenidae. Look around and under  nooks and crannies and on every dive you will find at least Pterois volitans (mainly black ones occur here). In shallower, more calm settings it's not unusual to see several Dendrochirus brachypterus perched on rocks, the sand or in seagrass beds.
Angelfishes, family Pomacanthidae. The Swallowtail, Genicanthus caudovittatus is quite abundant in places, as is the dwarf, Centropyge multispinus (though often unnoticed hiding). The occasional larger Red Sea Angel species do cruise by (see coverage below).
Goatfishes, family Mullidae. Two of the twenty three species found in the Red Sea stick out for beauty and utility (as sand stirrers), and general availability: Mulloides vanicolensis and Parupeneus cyclostomus (male shown at right).
Wrasses, family Labridae. The Red Sea is FULL of "Lippsfische"; some sixty nine species are found here, mainly associated with the sandy reef slope. Some are huge, others too boisterous for aquarium use, others are "just right".
Lizardfishes, family Synodontidae. Ten species occur in the Red Sea, some almost always in view on/near the sandy bottom, perched there or on a rocky area observing their world. Though rarely offered in the trade (they're not beautifully colored), these stealthy predators are ubiquitous on sandy shallows in the Red Sea (as well as most everywhere in the tropical Indo-Pacific). If you can find one of the more common species, give it a try, but not with small fishes that will become meals.

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