Parapriacanthus guentheri
Tiny golden schooling fish packing cave ceilings in South Sinai, Egypt, seen in water from 21.8 to 27.8 C year-round.
A tiny fish at around 4cm, translucent yellow-gold body with a faint silvery gut line visible through the skin. Found packed into tight, motionless-looking schools that shift as one under overhangs and in caves rather than swimming as individuals. No bold stripes or blotches; the giveaway is the sheer density of the school and the glassy, see-through look of each fish caught in torchlight.
Spend the dive tucked into the dark, packed tight under overhangs, in cave entrances or beneath coral ledges where light barely reaches. The whole school pulses and swirls as a single mass when disturbed but rarely scatters far, settling back into the same crevice once you move off. Best spotted with a torch, since the low light they favour also makes them easy to swim straight past.
Logged as uncommon at every site where it turns up, so finding one dense school on a dive feels like a small win rather than a given, even in its Sinai stronghold.
No clear seasonal pattern shows up in sightings, and with a comfortable range of 21.8 to 27.8 C it's present in South Sinai year-round. Any month diving the Sinai coast gives a fair shot at finding a school.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Egypt is where divers log this one, overwhelmingly in South Sinai and, to a lesser extent, the Red Sea Riviera. Look for it tucked into swim-throughs, cave mouths and beneath ledges at Sinai sites rather than out on open reef.
Mapping where Egyptian Sweeper is logged…
Almost every logged sighting comes from Egypt, concentrated in South Sinai with a smaller number of records along the Red Sea Riviera. Check cave mouths, swim-throughs and shaded overhangs at Sinai reef sites.
There's no detected season, and the species tolerates a wide 21.8 to 27.8 C range, so it's a year-round find in South Sinai rather than a seasonal target.
Look for a tightly packed school of tiny, translucent gold fish jammed under a ledge or in a cave mouth, each only about 4cm long. The give-away is the crowd, not any single marking.
They stay small, topping out around 4cm, which is part of why a single fish is easy to miss and the school is what actually catches your eye.
Across every site where it has been logged, sighting frequency comes back as uncommon, so it's a nice find rather than a guaranteed sight even on a good Sinai cave dive.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Anchovy
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