Cardinalfishes & trumpetfish. Part 6 of my documentary, “Mucky Secrets”, about the fascinating marine creatures of the Lembeh Strait in Indonesia. Watch the full 90-minute documentary at

In this video I first take a look at the Banggai cardinalfish, Pterapogon kauderni. This is an invasive species which was introduced to the Lembeh Strait in the year 2000, and now competes with anemonefish for territory. Although it appears to be thriving in the Lembeh Strait and a few other locations, the Banggai cardinalfish is nonetheless still an endangered species because of its popularity in the ornamental fish trade.

We then encounter other species of cardinalfish (Apogonidae) in the area, Moluccan cardinalfish, Ostorhinchus moluccensis, the orbiculate cardinalfish, Sphaeramia orbicularis, and the frostfin cardinalfish, Ostorhinchus hoevenii, sheltering in the spines of sea urchins.

Finally we witness a trumpetfish, Aulostomus chinensis, preying on a small group of frostfin cardinalfish. The trumpetfish’s slim profile and stealth allow it to creep up very slowly on the unsuspecting cardinalfish, before making its attack. The trumpetfish sucks in the cardinalfish in a method known as “pipette feeding”.

There are English captions showing either the full narration or the common and scientific names of the marine life, along with the dive site names.

The full Mucky Secrets nature documentary features a huge diversity of weird and wonderful marine animals including frogfish, nudibranchs, scorpionfish, crabs, shrimps, moray eels, seahorses, octopus, cuttlefish etc..

Thanks to Lahniz ( for the music track, “Blade Walker” and to Kevin MacLeod of for the tracks, “Hitman” and “Sneak ‘n Get Caught”. These tracks are licensed under a Creative Commons Attribution 3.0 Unported license.

Thanks to the staff and keen-eyed divemasters of Two Fish Divers ( for accommodation, diving services and critter-spotting.

The video was shot by Nick Hope with a Sony HVR-Z1P HDV camera in a Light & Motion Bluefin HD housing with Light & Motion Elite lights and a flat port. A Century +3.5 diopter was used for the most of the macro footage.

Read more:

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Full list of marine life and dive sites featured in this video:

00:00 Clark’s Anemonefish, Amphiprion clarkii, Police Pier
00:06 Banggai Cardinalfish, Pterapogon kauderni, Police Pier
00:22 Banggai Cardinalfish, Pterapogon kauderni, Police Pier
00:58 Banggai Cardinalfish, Pterapogon kauderni, TK 3 (Teluk Kembahu)
01:25 Moluccan Cardinalfish, Ostorhinchus moluccensis, TK 3 (Teluk Kembahu)
01:34 Orbiculate Cardinalfish, Sphaeramia orbicularis, Two Fish Divers house reef
01:49 Black Longspine Urchins, Diadema setosum, TK 3
01:57 Frostfin Cardinalfish, Ostorhinchus hoevenii, TK 3
02:10 Trumpetfish, Aulostomus chinensis, TK 3
03:25 Spotted Seahorse, Hippocampus kuda, Hairball