Meet Hippocampus nalu, new Pygmy Seahorse from South Africa

Extremely cryptic and always cute, Pygmy Seahorses are very popular among scuba divers and underwater photographers. First of them, Hippocampus bargibanti was described in 1970 and until 2003 remained alone, later accompanied by Hippocampus denise & Hippocampus colemani (2003) Hippocampus pontohi  (2008) Hippocampus satomiae & Hippocampus waleananus (2009), all from Western Pacific. Hippocampus japapigu was described from Japan (2018). Finally, 2 days ago (May 19) Hippocampus nalu was described from Sodwana Bay, South Africa. For me, this is the day of victory for underwater photographers and citizen science.

Hippocampus nalu.  Photo: Dr Richard Smith

The Sodwana pygmy seahorse was described by Drs. Louw Claassens and Richard Smith. But it was actually discovered three years before, when a local dive guide Savannah Olivier found and photographed this tiny creature. Dr Louw Claassens and Dr Dave Harasti arrived in Sodwana in 2018 looking for an entirely different animals. We can just imagine how shocked they were after dive guide demonstrated a photo of local pygmy seahorse! Definitely undescribed one, found 8000 miles away from other members of the group!

If you photographed pygmy seahorses you know it is far from easy! Sodwana Bay reefs are exposed to waves action and conditions for underwater macro photography are challenging. Congratulations to scientists and Savannah Nalu Olivier, Instructor and Dive Master, Pisces Diving, Sodwana. Great job!

Pygmy Sea Horses: more information and photos: Reef Fishes of the Coral Triangle

Crown of Thorns: the frightening beauty

Acanthaster planci (Crown of Thorns) juvenile, 1.5 cm.

First of all about the beauty: Crown of Thorns juveniles are really handsome in their own spiky-snowflake way. They develop spines and begin to feed on coral only about one year of age, drifting as planktonic larval before that age. Getting bigger and bigger they are gaining more and more brutality and spike length.

Acanthaster planci (Crown of Thorns) juvenile, 5 cm. with commensal shrimp

Adult Crown of Thorns can grow up to a huge size – more than metre in diameter! A few interesting facts:

– Crown of Thorns are a natural part of the coral reef ecosystem. An increase in their numbers only occurs when the reef is unhealthy.

– In healthy reefs Crown of Thorns are playing a positive role by eating some of the faster-growing corals and giving the slower-growing corals a chance.

Acanthaster planci (Crown of Thorns) young adult

– Adult Crown of Thorns can survive without feeding for up to nine months. The normal lifespan of a Crown of Thorns is about four or so years.

Acanthaster planci adult
Acanthaster planci feeding on branching corals

Lacy scorpionfish

Lacy scorpionfish, Rhinopias aphanes holds top position on the bucket list of many underwater photographers. You can not find this fish visiting regular diving destinations like Anilao or Lembeh, you’d add some adventure (and money) and visit Papua New Guinea, Australia or New Caledonia.

Usually they are found on offshore reefs, not deep, sitting motionlessly in ambush near crinoid, perfectly matching with surrounds. You are lucky if you managed to get a small collection of differently coloured Lacy – Golden, Grey, Greenish, Red.

Harpa harpa – beautiful predator snail

Harpa harpa

The family Harpidae comprises elegant marine gastropods with shell, resembling the strings of a harp. They are nocturnal hunters, hiding in the sand during the day and feeding on crabs and shrimps at night. The prey is enveloped by the foot and mucus, then saliva containing digestive enzymes is injected. Finally, partly digested crab is sucked out by the mollusc.

Amazing mimicry: Pseudoceros imitatus

Pseudoceros imitatus (Mimic Flatworm), one of my favourite flatworms, mimic Phyllidiella pustulosa (Pimpled Phyllidiella), very common toxic nudibranch. Phyllidiella can emit very toxic substances on the skin, extracting them from the sponges it feeds on. Our flatworm unfairly enjoys poisonous fame, avoided by predators!

Pseudoceros imitatus (Flatworm!)

Can you tell flatworm from nudibranch on this photo?

Do you see the difference?