Archive for February, 2013

Firstly, I must start off with several apologies.

Firstly, to the Sheffield Fluffykins Petting Zoo, I apologise for my attempt to teach the whole concept of ‘food webs’ using animals in the Zoo itself. This was on the whole uneducational, and on the rare occasion when the carnivores co-operated, incredibly distressing for the children present. So sorry about that. On the plus side, I hear Jimmy will be out of the hospital soon.

Secondly, to my colleagues at the laboratory. I accept full responsibility (in a moral, but not in a legal or financial, or indeed in any concrete sense) for the events of last Monday, which prior to any court case must remain undisclosed. I do, however, feel that the results we got may prove to be very exciting, once the area is declared safe to re-enter, and frankly I feel terms like ‘dangerously irresponsible’, ‘criminally negligent’ and ‘verging on war-crimes’ were thrown around far too liberally.

And finally, and most importantly, to you lot. I know that its been a long time since I last posted. I did intend to do a Valentine’s day special, but sadly time makes fools of us all. If this is in fact the first inkling you had that Valentine’s day had come and gone, don’t bother to rectify the situation. In all probability your significant other is so disgusted with you that even now they are participating in the most vile orgy seen since Caligula.

Of course, also I apologise wholeheartedly for the screaming nightmares you will be having after reading this. Particularly if you have two X chromosomes.

Its no secret that most people’s lives really were rather unpleasant in the years prior to around 1950. Before science and technology came along, everything was itchy, dirty, smelly and uncomfortable. You were ill for a lot of the time, for which the only cure were ‘twigs and a toad boiled in water’, spent most of your life engaged in back-breaking labour, and the only amusement was the occasional witch-burning. Of course, life tended to be even worse if you were female, mostly because your legal status varied from ‘second class citizen’ to ‘nice ornament in the corner’ depending on where and when we’re talking about.

But still. In those days there was still some romance, some love, some tenderness. Unless, of course, you were a female bed-bug (, in which case ‘stabbings’ replaced ‘romance’, ‘stabbings’ replaced ‘love’ and tenderness was replaced with ‘many, many more stabbings’. The reason for this is that bed bugs, along with a few other species of invertebrates, practice what scientists call ‘traumatic insemination’, normal people call ‘oh God, that’s awful’ and people in high security institutions call ‘ a sexy time’. Because, you see, during mating females get stabbed by the males. Specifically, by the penises of the males.

This is either some creature that lives under Mars and feeds solely on brains, or the reproductive organ of a male bean weevil (Callosobruchus analis)

As an aside, if you think that ‘stabbings’, ‘hypodermic needles’ and ‘sex’ are words that belong in the same sentence, please never go near me. I do not wish to meet you and hope you are recaptured as fast as humanly possible.

This behavior is actually found across several phyla – the nematodes, the arthropods, the gastropods and the flatworms. This means that is must have evolved repeatedly in different groups of animals, which in turn means that, like some deranged killer, Evolution was so proud of her handiwork in this case that she did it again and again. It is most prevalent in the so called ‘true bugs’, or Heteroptera, where it appears to have evolved at least three times (Tatarnic et al 2006).

Because all arthropods have what is called an ‘open circulatory system’, where all the organs are bathed in the heamolymph (the insect equivalent of blood, more or less), the males can pierce the female’s exoskeleton and release their sperm, which then migrate towards the ovaries of the female. This of course disadvantageous the female considerably (and we would like to be considered for the winner of ‘Understatement of the year’. Ed.) Although insects don’t feel pain (either that, or scientists are reluctant to let us know the full horror of the world around us) being stabbed repeatedly can lead to numerous infections (Reinhardt et al 2005). Of course, the female also has to dedicate resources to repairing herself after the stabbings, and the open wound is an invitation to infections. Indeed, in labs this can be a serious problem, with bed-bug colonies dying out through disease brought about by the stabbing-based orgies.

So, how come this behavior evolved, given that the females who practice it tend to die earlier? Logically, one would expect that the males which engaged in this anti-social practice would end up having fewer offspring that those males which did whatever the bed-bug equivalent of a romantic first date is. One possible explanation is that, in some animals, after mating the male simply ‘plugs’ the female reproductive opening, preventing further males mating with that female. Therefore, traumatic insemination allows future males to circumvent this problem in perhaps the most horrible manner possible. Another explanation is that it simply saves the male time spent on courtship displays, which I guess is rather like a bank robber saying he robs banks because working for the money would take too long. Finally, of course, it could be a solution to the problem of a female that does not want to mate at all.

“This is taking too long, and I’ve better things to do. I should probably just stab her with my penis”

Some female bugs, such as the African Bat-bug (Afrocimex constrictus) mimic male structures, presumably in an attempt to avoid these costly inseminations (Reinhardt et al 2007). However, this might not always work, even if the males are taken in.  ‘Homosexual traumatic insemination’ has been noted to occur (in places other than prisons, I should note) and in some cases it appears that it can happen between species. This can lead to fatal immune reactions in the insect stabbed, and also indicates that the insects which practice this method of mating are either very short sited or have very, very low standards.

Advertisements

Ah, another delayed blog post, and I’m afraid this one will be rather short. Recently I’ve a) been offered a PhD place and b) had to do a lot more work on my final year project. So that’s the reason posting has been a bit light. Both the PhD and the project are actually all about food security, which I know will be a relief to all of those of you who actually know me.

Pic unrelated. Honestly. There’s only like a 12% chance I will accidentally end civilization.

 

But anyway, on with the show!

In the eighteenth or nineteenth centuries, all you needed to do was to walk into a bit of wilderness, fire a weapon several times into the jungle, and then sort through the piles of animals you’d killed until you came across one which had not previously been known about. Then, you’d go back home with the carcass in tow, and you’d be renowned as the person who discovered a new type of animal. And not just a slightly different variety of insect, either. Gorillas, which you may recognise as been ‘fairly large’ animals, were only formerly described in 1847, and the first ones in the wild were by a Westerner were observed by Paul du Chaillu in the late 1850s. This is perhaps an appropriate point to mention that he also shot several of them , which was what all the cool biologists were doing in the nineteenth century. This style of fieldwork is somewhat frowned upon nowadays, to the relief of conservationists and the dismay of manufacturers of ‘laboratory grade’ firearms everywhere.

Now, biology is rather more sedate, specialised and involves rather less shooting things. Its now thought more important to work out how animals fit into their environment, how they interact with it, and how their adaptations allow them to thrive in their habitats. After all, its not as if there are any more giant, impressive animals lurking out there for us to discover, is it?  Well, probably not that many, at any rate, although what lurks in the deep sea is still in many ways a mystery – although we can predict that any animals newly discovered down there will be repulsive, consist mainly of eyes and teeth, and harbour nothing but a dark thirst for our souls.

Sometimes, the old methods of fieldwork may actually be the best (Photo is of a viperfish (Chauliodus spp) and is from Wikimedia Commons)

 

However, that doesn’t mean that animals we thought we thought we knew a lot about can’t harbour some surprising – and since they’re featured on this blog, disturbing – features. And that, neatly enough, brings us on to Moray eels. There are around two hundred species of these snakelike, wriggly fish (to use a very scientific term) and they are found all over the oceans, and sometimes into bays, estuaries and rivers (http://www.fishbase.us/summary/FamilySummary.php?ID=56) . The longest,  Strophidon sathete can reach around four metres in length, and some species can give a nasty nip if provoked (although many attacks are actually due to divers feeding them, and the near-sighted eels mistaking fingers for food).

“Yeah, sure. ‘Mistaking’” (Photo credit: Wikimedia Commons)

And also, there’s the small matter of that whole Alien-style second pair of jaws they have in their throat, which somewhat unbelievably was only really discovered in 2007 (http://www.nature.com/nature/journal/v449/n7158/full/449033b.html).

Now, before you get all excited, lots of fish actually have second pairs of jaws hidden in their throats; these jaws are called ‘pharyngeal jaws’ and are often used for grinding up hard food before it is swallowed completely. So the Moray Eels aren’t exactly alone in this regard.

Where they are alone is that they can actually move these jaws forward. In most fish, these jaws just stay there, grinding up whatever food is sent their way. These eels, however, can move these jaws to just behind their regularly set of jaws, grab hold of their still living prey, and then drag it back down towards the oesophagus. They are, in short, the only animals to actually use these jaws to assist in the actual capture of prey. This is because, unlike most fish, Morays cannot produce the negative pressure which most fish use to assist in swallowing their prey. Whilst most fish basically use suction to assist in prey-capture, the Moray eels just use a second pair of jaws; and it is this adaption that could be the reason why Moray eels are so widespread (Mehta and Wainwright 2007).

How the jaws of the Moray Eel work – they spring forward inside to help grasp the prey. (Photo credit: Wikimedia Commons).

 

The really remarkable thing about this is that this mechanism was only discovered in 2007, when the authors of the above paper used high speed video to observe Muraena retifera feeding, curious as to how it fed given that it couldn’t use suction. It was only at this point that scientists realised that yes, it had a set of these pharyngeal jaws, found nowhere else in the animal kingdom, despite the fact that throughout the years several dozen dissections, at least, must have been carried out on these animals, not to mention hundreds of photographs, observations and experiments.

Kind of makes you wonder what else we’ve missed.

 

“Yeah, sometimes they shoot fire out of their eyes and feast upon the innards of still living children. We never really noticed it before, I guess.” (Photo credit Wikimedia Commons)