The photo shows part of the periwinkle’s gut dissected to reveal an infestation of pale, ovoid structures. These are known as sporocysts and they’re much less than 1 mm long.  Every one of these sporocysts developed from a single miracidium, a ciliated organism that hatched from an adult fluke’s egg. The video reveals the macabre secret contained within these sporocysts.

Part of an unfortunate periwinkle’s gut. This individual was infested with sporocysts (pale, ovoid structures), one stage in the life cycle of a fluke (Ross Piper).

The cercariae released from the bulging sporocysts are another infective stage in the parasite’s life cycle and it is their task to penetrate the body of the definitive host (unknown in this case) where they develop into the adult fluke. For a fluke, the example above is a relatively simple life cycle. In other species there are yet more body forms and serial repetition of some stages to produce colossal numbers of cercariae from a single egg. What is the significance of this singular reproductive strategy? Well, in short, huge numbers of offspring produced asexually offset the huge odds stacked against any one juvenile completing its development. You have to love the incredible complexities of such animals that are often disregarded as ‘simple’.

Such a strategy is a long shot to say the least, so to offset the long odds huge numbers of offspring are required. With a body only a few millimetres long the nematode is rather limited in how many eggs it can produce, but to get around this problem something incredible happens to its gonads. Its entire reproductive system turns inside out and balloons to relatively enormous proportions, eventually dwarfing the nematode that dangles at the end of this structure like a vestigial appendage (see photo below). With unfeasibly large gonads the nematode can produce tens of thousands of eggs.

Dwarfed by its enormous, inside out uterus, the nematode, Sphaerularia bombi, can be seen near the centre of this image (image from Mark Blaxter’s teaching pages).

This is another type of predatory, solitary wasp, but this species exhibits an incredible degree of sexual dimorphism. The individual in the photo below is a male and compared to the female (see here for the female of a related species) he’s a veritable pin-head. Apart from his odd-shaped head the male also has very distinctive, enlarged fore-legs, perhaps for signalling to the female and gripping hold of her when his courtship has been well-received. Active hunters, female Lestica wasps stock their nests with small moths. The dandy males, on the other hand, simply spend their time looking for females and sipping nectar.

A pin-headed male Lestica sp. Sexual dimorphism is very distinct in this genus of solitary, predatory wasps (Ross Piper).

Male Lestica spp. have a very odd-shaped head and large, flattened fore-limbs (Ross Piper).

This post concerns Ectemnius wasps in particular. These have to be right up there amongst my favourite animals. If you’ve ever observed these wasps you can’t help feeling they’re rather smart. Sharp-eyed, they watch their surroundings intently, their little heads flicking this way and that in search of mates, prey and enemies.

To give you a better idea of just how good the vision of these insects is I took the liberty of photographing their heads through a microscope. You’ll see from the photos below that their eyes are relatively enormous and are composed of hundreds of individual facets (ommatidia). There’s no question that eyes of this type are second to none when it comes to detecting movement, but they must also be able to form pretty decent images if the fussy dietary requirements of these wasps are anything to go by. Ectemnius wasps prey on flies, typically hoverflies, but also muscids, etc. which are masters of the air in their own right, so hunting them, often on the wing, requires an amazing coordination of flight and vision. The images formed in the brains of these wasps from the information streaming in through their compound eyes must be sufficiently detailed to allow them to single out their prey from inanimate objects and other similarly sized insects.

The massive compound eyes of a predatory solitary wasp (female Ectemnius cephalotes). Note the fine silvery ‘moustache’ (Ross Piper).

If you were a hoverfly you would not want one of these bearing down on you. The fixed gaze of a female Ectemnius continuus (Ross Piper).

This chance observation really goes to show how many struggles and interactions go on unseen under our noses. Typically, sarcophagid (flesh flies) larva eat decomposing animal matter, but perhaps many of them have more specific tastes, actively hunting out other animals to feed on?

A flesh fly larva predating an earthworm (Ross Piper).

Try as it might the earthworm just couldn’t shake this little predator (Ross Piper).

Massive and completely black, they scuttle around in the dead of night chomping any suitably sized animals that venture within range of their enormous mandibles. Unlike most their kind they’re completely flightless and relatively cumbersome. The fine specimen in the photo below was found at a campsite we stayed at in Namibia at the end of 2011. It was lurking under the low vegetation growing around a lamp-post, idly waiting for other insects drawn by the light to lose their bearings and fall to the ground.

Getting close enough to most tiger beetles to take decent photos is a bit like herding cats because they’re just so fast and skittish. However, these beefcakes of the tiger beetle world are much more relaxed and this one happily made a small snack of several flying termites while I had my camera in its personal space. After growing weary of the flash the beetle scuttled off like a wind-up toy. The next challenge is to find the fully-grown Manticora larva. It would look a bit like this, only much much bigger.

If you want to find out more about these splendid insects then this paper is packed with information. There are even some photos of the formidable larvae, their tunnels and their parasitoids.

The African Manticora spp. are the biggest and meanest looking of all the tiger beetles. Thirteen Manticora spp. are currently known from throughout sub-Saharan Africa (Ross Piper).

Here’s the same specimen unceremoniously dispatching a winged termite (Ross Piper).

Animals come in a huge range of shapes and sizes, but the vast majority of them are very small. In fact there are many animals that are way smaller than some single-celled organisms.

Here, on the right is a rotifer, an animal with a body made up of around 1,000 cells. At the top, contracting rapidly, is a ciliate, a single-celled organism (Spirostomum spp.). The tip of a needle gives a sense of scale. Disappearing behind the needle at the start of the video is another single-celled organism.

It is creatures like this that really underline the multi-layered complexity of biodiversity. These cilates, swimming around in a small pond, are little bigger than a full stop yet they dwarf the rotifers that crawl and dart around them. Humans on the other hand are big organisms, vastly bigger than most other animal species, but this smaller majority is effectively hidden in plain view, which makes it difficult to appreciate the riot of animal life that surrounds us.