Creature Feature – Get to know the Seahorse

Want to get a bit closer to the shyest fish in the ocean?  The strangely beautiful, secretive seahorse is always a diver favourite!

Here’s some fun facts about the enigmatic seahorse!

Sea Monster

The 45 species of seahorses belong to the genus Hippocampus, a word which is derived from ancient Greek, and means horse sea monster!  What a fearsome name for such a beautifully shy creature!  It’s said that the seahorse is the strangest mish mash of different animals – with the head of a horse, the tail of a monkey, the pouch of a kangaroo, the outer skeleton of an insect, and the independently moving eyes of a chameleon.  Yet somehow nature brings this all together to an amazingly elegant, non-mountrous whole!  No wonder seahorses have intrigued people, and inspired myths and legends since the dawn of humanity!

Hippocampus in Roman mosaic in the thermae at Aquae Sulis (Bath) - image used under Creative Commons Attribution
Sea horse at Whales Head dive site on the corridor in Los Cabos Mexico

Upright Fish

Seahorses are really peculiar fish, as they swim upright – head up, tail down, perfectly poised – totally unlike most fish.  Even their closest cousins, the pipefish swim horizontally.  In fact, razorfish are the only other fish that are known to swim vertically!

Seahorses propel themselves forward pretty much solely using just their dorsal fins.  These little fins can beat at a rate of more than 40 times per second!  That’s so fast that it can exceed the point of flicker fusion in humans – meaning it’s too fast to be detected!  Stealthy!

Romantic Bonds

One of the most endearing things about seahorses is that they form faithful pair bonds during the breeding season.  Every day, paired males and females come together for a few minutes to greet each other.  Shedding any attempt at hiding or camouflage, they will visibly brighten in colour, twirl and dance around each other, and often entwine tails and swim in synchrony.  Aaawww.. Love is beautiful! 

And, they do remain faithful!  It has been shown experimentally that if a pregnant male seahorse is removed, his female partner will not mate during the span of his pregnancy, even if another potential mate is available.

Courting sea horses - image used under Creative Commons Attribution

Male Pregnancy

Yes, famously, it is the males that bear the burden of pregnancy, and are responsible for looking after the eggs and developing embryos.  Male seahorses have a special pouch attached to their tail, into which his partner will deposit her eggs, after a beautifully complex mating ritual.  The male usually initiates this by vigorously pumping water in and out of his pouch, showing off its size and emptiness.  His suitably impressed partner will then join him in a mating dance, involving beautiful colour changes, synchronised swimming and fin fluttering.  Ultimately they’ll bring their genitals together and she’ll insert her eggs into his pouch.  Once the eggs have been transferred, he retreats to a quiet place to begin his pregnancy.  The daily pair greetings continues, while the female starts work on a new batch of eggs.  Love that they’ve figured out the right balance for division of labour!

Baby Seahorses

Seahorse pregnancy can last from two to four weeks, and produce between 100- 1000 babies per brood!  Giving birth is a seemingly painful process, with the male undergoing strong contractions, and jack knifing his tail against his pouch in order to expel the babies.  Sometimes he may even ground his pouch against a rock or shell to push the babies out.  Baby seahorses are born looking like exact miniatures of their parents, and are independent from birth – left to fend for themselves in the big wide ocean!

Bargibant’s pygmy seahorse - see them on expedition with Dive Ninjas

Pygmy Seahorse

One of my favourite creatures – the pygmy seahorse!  These tiny and super well camouflaged creatures only grow to about 2.7 cm long.  They are incredibly difficult to spot among the sea grass, soft coral, or gorgonians sea fans that they inhabit – so much so that they weren’t even discovered until 1969!  Scientist George Bragibant was examining a gorgonian sea fan on his dissection table when he happened to notice a pair of tiny seahorses – discovering the Bargibant’s pygmy seahorse, a diver favourite!  With bulbous tubercles all over its body to match the colour and shape of its host sea fan, they are incredibly hard to spot, although super rewarding when you do!  It’ll definitely feature on any macro photographer’s wish list!

Slow Swimmers

Seahorses are ridiculously poor swimmers.  They are the slowest moving of all fish, relying only on the little dorsal fin on their back, and are known to get fatally exhausted when waters get rough during storms. 

However, they make up for this by having super strong prehensile tails, which allows them to anchor themselves onto coral or seaweed.  This lets them to hide in place to rest, but also catch a ride on floating vegetation, hitch hiking their way round the reef!  Some seahorses are even known to use sea urchins as a holdfast, getting a free taxi ride!

Seahorse hanging on fast to coral - come find them with Dive Ninjas!
Pygmy seahorse in the Philippines - come find them with Dive Ninjas and LAMAVE!

The Very Hungry Seahorse

Who would have thought that the demure looking seahorse is actually a voracious hunter!  Seahorses don’t have a stomach – and their limited digestive ability means that they have to feed constantly!  In a single day, a seahorse may eat several thousand small prey items – from tiny crustaceans, small fish, eggs, snails – anything that’s small enough to get into their snout is fair game!  They rely on their super camouflage ability, thanks to helpful chromatophores cells in their skin, to avoid detection, before rapidly snapping their heads forward to vacuum up their food.  Now that’s a little fish with a big appetite!

Interested in getting up close with one of the most charismatic little creatures in the ocean?  Come with Team Ninja as we try to spot the Pacific Seahorse in its local hangout in the bay of Cabo San Lucas.  Or join us on our upcoming trip to seahorse hotspots in the Philippines Contact us today to find out more, or sign up!

Check out the Ninja Philippines Conservation Trip

Diving in Xcalak Mexico with Dive Ninja Expeditions & Girls That Scuba

Ninja Family Guest Writer:

Sze Wei

Lover of all marine animals big and small – and ok, yes, I like diving a lot!  When not underwater, I can be found in London with my goldfish.
Follow Sze Wei on Instagram