Further adventures at the aquarium

(Photo copyright: Anne Lawson)

Most of my time at the Melbourne Aquarium was spent in the section of seahorses, seadragons and pipe fish. I stood and watched for ages. (Apologies in advance about the quality of the photos. They were taken through glass, and while seahorses don’t dart around, they can move more quickly than this photographer would like!)

You can see why the seahorses have caught my fancy. They are delightful little creatures.

A little about seahorses (but please stop me if I go on too long!)

They are fish, and live in three main habitats — seagrasses, corals and mangroves. They belong to the Syngnathidae family, in reference to their fixed jaws (syn — Greek for “with” or “together”; gnathos — “jaw”.) Seadragons and pipefish are in the same family. The genus of seahorses is hippocampus. The big-belly seahorse has the grand name of Hippocampus abdominalis. But my favourite might be Hippocampus guttulatus or the long-snout seahorse.

Good camouflage! (Photo copyright: Anne Lawson)

They are only small, ranging from a species that is about 2 cms (fancy that!) to the big-belly seahorse which is around 30 cms. Theirs is a solitary life, except at mating time, and they don’t travel far. When they do move they use their tiny, transparent fins and then attach themselves to seaweed. They could be easy prey, but have two defensive adaptations. Firstly, unlike other fish they don’t have scales. Instead they have bony plates. It gives them their distinctive shape and makes them unappetizing to other fish.

Bony plates and spikes make seahorses difficult to swallow (Photo copyright: Anne Lawson)

The other adaptation is their excellent camouflage. To escape the predator they blend into the background, often mimicking the colours around them.

They might be hard to see, but there are at least five seahorses in this photo! (Photo copyright: Anne Lawson)

They eat zooplankton, which they suck up through their snouts. It seems like a hard way to get a meal, but they can eat really quickly.

Of course, the seahorses’ real claim to fame is that the fathers get pregnant, nurture the young in an adapted pouch and give birth to the live little ones. (Are baby seahorses called ‘foals’?)

(Photo copyright: Anne Lawson)

Like so many species they are under threat in the wild. They are hunted to be used in Chinese medicine — at least 70 tonnes or 25 million seahorses a year, according to one source I read. Trawling for shrimp is another danger. There is so much wastage, as species other than shrimps get caught up too. For every kilo of shrimp an additional 5 to 10 kilos of other species are dragged to the surface. Trawling also does long term damage to the sea bed, especially in the shallower waters which are the seahorses’ habitat. Add warming of the oceans to that list, and you can see that these wondrous little creatures need help to survive.

(Photo copyright Anne Lawson)

 

(My information has come from a charming book Poseidon’s steed: the story of seahorse, from myth to reality, by Helen Scales. However, any mistakes that I have made in this post are all my own!)