Underwater alien inspiration

20:27, Nov 11 2012

Some of New Zealand's freshwater wildlife looks as though it just stepped off the set of Starship Troopers.

Dragonfly larvae.

First is this impressive looking dragonfly larva. When we were kids we had a creek out the back of our house in Twizel. We spent hours and hours playing and exploring out there, and one day I thought I had discovered a new species upon finding several dragonfly larvae under the rocks in the streambed. Of course, it was not a new species of animal, but I have remained fond of these incredible little aquatic predators ever since. Coolest thing? They have extendable jaws that fold back into their head!

The feathery gills of the burrowing mayfly.


Burrowing mayflies do just as their name suggests, burrowing into the gravelly substrate in riverbeds and eating the organic detritus that gathers there. The beautiful white feathers of the burrowing mayfly remind me of Falcor, that lovable dragon in The Neverending Story.

Apart from being awesome looking, freshwater invertebrates play a crucial role in the protection of our rivers, lakes and wetlands. A healthy population of freshwater invertebrates tells us we have a healthy river, stream or creek.  A lack of these important indicator species tells us all is not well.

Kokiria caddisfly.

The Kokiria caddisfly is one such indicator, and is found only in stony and sandy streams in the north and west of the South Island. Like other caddises, they live inside a protective case. In this instance, the case is made of sand grains and is extended above and around them so that they can't be seen from above.

Richardsonianus mauianus is a blood-sucking native leech.

This handsome-looking chap is one of our native leeches.

Richardsonianus mauianus is one of the few blood-sucking leeches we have. They are also very cool looking and their striking black and yellow stripes would make them a great mascot for the Phoenix Football Club. This leech is pretty rare in most places, and is occasionally found in slow-flowing weedy streams. We had some of these in our zoology lab at university, and they were amazing to watch swimming (they move through the water like undulating ribbons).

Tadpole shrimp.

Probably the coolest space-age looking invertebrate I know of is the AMAZING looking tadpole shrimp.  They are considered a living fossil, since they haven't actually changed since the Triassic period. They remind me of horseshoe crabs, but they aren't closely related to them at all. Tadpole shrimps have an interesting lifestyle, living in temporary shallow ponds and pools. When these pools dry up, the adults and their drought-resistant eggs lie dormant until the water returns. I've never seen them, but I'd like to!

So, overall our invertebrate aquatic fauna are incredible-looking creatures that would be a life's worth of inspiration for someone like James Cameron. If anything, we should look after them, because they tell us that our rivers are healthy and clean. If you want to know more, the good folk at Landcare Research have created this webpage to help you identify any freshwater invertebrates.

You can look after your own underwater aliens by planting the edges of your streams, fencing them off from livestock and protecting and maintaining flow and water levels.

Did you know we had such awesome looking underwater wildlife? Have you seen any? I'd love to hear about them.

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Pictures: Stephen Moore/Landcare Research