Seahorse

Image: Nick Hobgood

Seahorses are fish who can barely swim and the males get pregnant. Seahorse, you're doing it wrong!

I've never really understood Seahorses. For me, they occupy a strange, ambivalent realm where they can appear charmingly eccentric or nightmarishly crippled depending on how I feel at the moment.

Image: prilfish
Thorny Seahorse (H. histrix)
Not good at being a fish

Most fish look pretty good as fish. They may be streamlined and limbless but they have everything they need to survive and do what they need to do.

Seahorses are different. I can't escape the feeling that they were meant to have arms. Their body is bent and broken out of shape and then covered in bony plates to make sure they stay that way. They are indeed close relatives of pipefish, except they look like they've spent too long bent double down a mine.

I weep!

Image: WoRMS for SMEBD
Maned Seahorse (H. guttulatus)
Go home, scary Seahorse. You're drunk.
On second thoughts... drown your sorrows, mate.

Their tiny mouth is at the end of a long snout and fused jaw so they can only suck tiny bits of food from the water which they spot with desperate eyes. These eyes can move independently of each other, which is pretty cool except that it mainly compensates for the horrible fact that the Seahorse can barely move anything else.

Image: PacificKlaus
White's Seahorse (H. whitei)
The googly eyes of a monster?

All in all, it's just like when Hannibal Lecter was wheeled out for the senator. Which makes me wonder what's going on in that malformed head of theirs...

"Take this THING back to Baltimore"

Image: Andrew Dunn
Hippocampus. Back when they ate liver

At least someone out there knows what's what - the 50 or so species of Seahorse belong to a genus called Hippocampus, which means "horse monster".

Unfortunately for them, Seahorses don't have half a dozen men in uniform to take them around the place. Instead, they must rely on a tiny dorsal fin which flutters pathetically in the water. Pectoral fins on either side of their head are used for steering, and they're so tiny and badly placed that they only really work because the Seahorse is so depressingly slow.

Image: San Diego Shooter
Dwarf Seahorse (H. zosterae)
World's Slowest Fish, 2009
At 5 cm (2 in) long, not the smallest

The Dwarf Seahorse has achieved the dubious award of World's Slowest Fish from the Guinness World Records. It swims at a speed of 1.5 metres (5 feet) per hour. There are starfish who can travel that far in a minute or two. Starfish! Yeah... "congratulations".

It's our old friend the Pygmy Seahorse! Some of them are just an inch long

Needless to say, Seahorses do what they can to avoid getting caught out and forced to swim like a fish. Because it's really difficult to do that when you're a mangled fish.

Image: richard ling
Big-belly Seahorse (H. abdominalis)
One of the biggest at 35 cm (13 in) long

So while they can be found across the world in tropical and temperate waters, they always stay near the coast in areas sheltered from the currents.

This is where the prehensile tail comes in. Other fish have a tail with a fin attached, and they use it to power through the water and do amazing things like go from one place to another place. Seahorse tails are completely different. They're curly-wurly and are wound around a branch of coral, a plant stem, or something else that doesn't go anywhere. This helps our woebegone Seahorse be in a place and not go to another place.

Image: Hans Hillewaert
Short-snouted Seahorse (H. hippocampus)
Surrounded by copepods/lunch

And there they stay, sucking up tiny crustaceans with their puny mouths and hopefully camouflaged because if they're not, there isn't much they can do about it. It's almost idyllic, in a way. Relaxing there in calm waters, plucking food as it drifts toward you, watching the world go by with your giant, freakish eyes... It's just a pity that you don't actually have a choice in the matter. And the only thing that can ruin paradise is not having the choice to leave.

Image: Andreas März
Slender Seahorse (H. reidi)
Time to boogie

Is it any wonder that Seahorses seek solace in the... twirly tail (I can't say "embrace") of the opposite sex? It's nice that despite their multifarious impairments, Seahorses still find each other attractive. They accept each other for who they are even if I don't.

And so it's time... for The Forbidden Dance.

Video: Daragh Owens

Seahorses are famous for the elegance and grace of their courtship dance. They follow each other around, synchronising their movements, they hold tails (they can't hold hands) and whirl around each other, they grasp a bit of coral and spin around it (the kind of thing I think was mandatory in musicals whenever a happy couple passed a lamppost).

It's all thoroughly delightful! And it's pretty cool that the Seahorse is so rubbish at swimming around that they use the act of swimming around to demonstrate the profundity of their love. That's sacrifice!

You will also notice that carrying a little extra weight is no excuse when it comes to strutting your stuff. The male of the species has a brood pouch...

Video: nataquarium

Which he opens up to demonstrate the gaping emptiness within. This is, of course, utterly obscene, but it always is when you're on the outside looking in. Er... outside of the relationship, I mean.

Then again, this pouch is exactly where the female deposits her eggs once they've been fertilised. There may be anything from a hundred to a couple thousand eggs in there, all cosy in their father's swelling belly.

Image: OZinOH
Big-belly Seahorse demonstrates its name.
Some Seahorses get more pregnant than others

He now spends the next few weeks quietly feeding and nourishing the growing sprogs safe and secure within his body. His mate visits him each morning and they renew their relationship with a few minutes of ritualised dance. This ensures the male doesn't turn bozo and lose all her precious eggs and it also makes lifelong marriage sound quite easy. Just dance. You could even turn it into a morning exercise regime.

Thing is, not all Seahorses are as faithful as others. Some species may well mate for life, others only for a single season. There are some that breed in groups (a love polygon, I suppose) and at least one species, the Big-belly Seahorse, seems happy to flirt and court any male or female of its own species who happens to be around. Sort of like a nightclub.

Image: richard ling
Shame on you!

One guy who was sitting there watching them do it said "they really are indiscriminate and shameless creatures". Yeh, but... as I said, it always is when you're on the outside looking in. That's where "get a room" comes from.

After fooling around with every Tom, Dick and Harriet, even the most promiscuous of Seahorses will eventually produce or incubate a whole gut full of eggs.

Video: thedeephull

They hatch within the male's pouch and once they're ready to be released into the wild, their dad contracts his heaving belly with the kind of violence usually reserved for seasickness. The babies are rudely thrust into the sea like bubbles from a... thing you blow bubbles out of. A circle on a stick, or whatever you call it (I'm going somewhere with this).

And just like bubbles, almost all of them are destroyed (this is the Art of writing, dear reader. Honestly, it's a burden). Their father secures the eggs from predation but the vast majority of baby Seahorses still get eaten or whisked away on the currents, and it may be months before they reach adult size. And then they can STILL get whisked away on the currents. All of which is why the male Seahorse is soon ready for a whole new pouch of eggs.

Image: brian.gratwicke
Shortsnout Seahorse (H. breviceps)
Awwwwww!

Through luck and sheer numbers, a few tiny Seahorses will grow into the majestic, broken-backed, deformed, enfeebled, maimed and marred (I have more) semi-invalid fish we know and can't quite understand.

And I still think they would appreciate some extra limbs..