E.O. Wilson once described insects as "the little creatures that run the world". Wilson was presumably referring to the huge amounts of energy and mass that pass through insect bodies in terrestial ecosystems. There are, slightly puzzlingly, almost no insects in the sea but invertebrates still run marine ecosystems. In fact, invertebrates even create habitats in what would otherwise be unproductive waters.

We tend to think of the tropics as areas of great biological diversity - that's true for the land but less so in the ocean. The beautiful clear waters you see in tropical seas indicate a lack of nutrients and a corresponding lack of plankton. Without plankton, the normal marine food webs don't develop and, as a result, tropical seas are generally not very productive. But if you've been snorkling around a tropical island you'll know coral reefs are explosions of biolgical diversity. That's all because some coral animals can take advantage of the marginal conditions in tropical waters. These corals supplement the meager pickings that can filter from the water with energy trapped by a type of photosynthetic protozoa called zooxanthellae. In time these corals, with their protozoan helpers, can put down acres of calcium carbonate and create food and habitat for more and more animals. When those animals are anenomes, they can themselves form habitat for another animal. Like this anemone fish (or, as most people call them, NEMOS!!!) filmed earleir this year at Hideaway Island in Efate, Vanuatu:

Labels: anemone, coral, environment and ecology, sci-blogs, sunday spinelessness, vanuatu, video

I spend quite a lot of my time trying to convince people that very few snails or slugs are interested in eating their lettuces. But it has to be said, there are a few terrestrial gastropods that are serious pests. In New Zealand, those are all introduced species and the "grey field slug", Deroceras reticulatum, is the one we run into most often. These slugs can destroy freshly planted vege gardens, they're a major pest for commercial growers and they can force out native species in disturbed forests. So, they're unquestionably bad news. But the baby one I found in the cauliflower today was quite cute:

Labels: environment and ecology, photos, sci-blogs, snails, sunday spinelessness

I had planned to write about snail shells today. Specifically, about how chance mutations that change the direction of a shell's spiral might be enough to create a new species. I guess that story will have to wait another week, today I'll just share (what I think is) a particularly beautiful spiraled shell I found recently.

I'm not sure what species of snail once lived in this shell. I found this one, and 20 or 30 more, under logs and in leaf litter in the the fuchsia-dominated remnant forest (yes, in New Zealand fuchsia comes in tree-form) in Fraser's Gully. There's a clue to the taxonomic placement of the animal that used to inhabit the shell on the flip-side.

The hollow cone shape that forms at the bottom of some snail shells is called an 'umbilicus', and it's a taxonomically informative character. In the New Zealand land snail fauna, the family Charopidae is assoicated with large open umbilcuses like this one. There are charopids that have closed shells, and there are snails from other families that have this sort of open umbilcus - so its presence isn't the final word, but it's something to go on and I'll have to do a bit of sleuthing at some stage and see if I can work out what these snails are.

Whatever their placement, I was taken by these shells because of their lovely pattern. Something I more or less failed to capture in the obligatory front-on shot of the shell (sorry, I don't even have time to photoshop the blue-tac out today!):

Labels: environment and ecology, photos, sci-blogs, shell, snails, sunday spinelessness

You can tell from the increasingly brief nature of these posts, that I have quite a lot on at the moment. Between trying to polish off these thesis chapters, finish edits to paper I contributed a little bit do and teaching my very first lecture last week I've been a little busy. I do have time to share a couple of photos I took to record the visit of queen bumblebee.

It's really not bumblebee season in Dunedin, so I was quite surprised to hear that familiar baritone buzz in my kitchen a couple of weeks ago. In temperate climates like Dunedin's, bumblebee nests survive the winter by putting all their investment into a few queens who mate at the tail end of summer then hibernate in some warm-looking spot (often a disused rat's nest), biding their time so they can establish a new nest in the spring. I don't know if the bee that made it to my kitchen had been fooled by a couple of warm days, or if it was a straggler from a nest that had tried to make it through the autumn (in Northern New Zealand bumbleebee colonies can find enough flowers to eek out an existence over the winter, but I can't see that working down here), by the time she got to me she wasn't doing very well (note the splayed, face down posture)

The buzzing I'd heard wasn't so much the bee flying about searching for a way out as her attempts to build enough temperature in her flight muscles to let her take off. The muscles themselves need to be around 30 °C before they can work, but bumblebees can operate when the outside temperature is as low as 6°C by uncoupling their flight muscles from their wings and vibrating them. As David Attenborough explains, bumblebees are warmblooded insects!

My visiting queen didn't appear to be winning her battle with the thermoregulation, so I scooped her and but her under a desk lamp in the hope it would help. The fact I might be able to take photos of her at the same time was, of course, just a happy side effect of trying to help her out. I really failed to take any interesting photos, but I do quite like this detail of the hairy abdomen and veined wings:

I hoped focusing on the tail-end of the bumblebee might reveal the fact that bees (and their relatives the wasps and the ants) have two pairs of wings (which is the ancestral state for insects). But, in fact, the smaller set of wings are so tightly connecting with the larger ones it's impossible to see here. You'll have to look at some disembodied wings to see that I'm not making it all up.

You'll be glad to know a couple of minutes under the lamp, and her concerted efforts, were enough get the queen back in the air - she was last seen flying upwards and hopefully towards a good spot avoid the snow that fell here recently.

Labels: bees, bumblebee, environment and ecology, hymenoptera, photos, sci-blogs, sunday spinelessness