A freshwater ciliate

I am an amateur naturalist trying to discover everything living in my garden.

Some time ago I wrote about the Haematococcus algae I discovered in a puddle in my garden. At the time I enthused about the book Freshwater Microscopy by W.J. Garnett, a guide from another era for the amateur to culturing and identifying pond life. Inspired by the book I recently revisited my puddle and was well rewarded with a number of tiny critters new for me. Photo 1 (click to enlarge) shows three : a) A ciliate (more below) b) what I think may be a cyanobacterium and c) another ciliate that I think may be a paramecium. (As always my identifications come with a health warning. I'm happy to have them corrected).

Photo 2 shows a closeup of 'a' taken at 1000x magnification using my microscope's oil-immersion lens. Features to note about my organism are its large nucleus and the numerous swimming hairs (cilia) covering its body.

Those interested in such arcane matters (those not may like to skip this paragraph) may like to know the specimen here was stained with ~0.01% aqueous Eosin dye then mounted in a mix of water and glycerin with a little added disinfectant (to prevent future growth of mould). In an attempt to render the slide permanent I adopted the 'double cover slip method' . There's a detailed explanation of this here but briefly it involves sandwiching the specimen in its aqueous mountant between two differently sized coverslips, then mounting this sandwich in turn in a solvent based mountant (Permount in my case) thereby sealing in the aqueous mountant against evaporation and hopefully rendering the whole arrangement permanent. (Since acquiring my hobbyists microscope a couple of years ago I've developed a growing passion for making up microscope slides!)

Returning to my specimen itself, I have a couple of basic photoguides to pondlife and from images in these, and the general size (~40um) and form of my ciliate, I was tempted to identify it as a species in the genus Colpidium. You can find some stunning photo's of this and other protozoa here. From the volume of images on the web this seems to be a not uncommon find in pondwater. Unfortunately however, having looked at the equally splendid Protist Images website I'm no longer so confident. The problem is that the phylum Ciliphora (=little organisms like mine with cilia) is broken down into such a large number of superficially similar genera that it's hard for the amateur like me to know that my wee beastie is definitely a Colpidium and not say, a member of the catchily entitled Trithigmostoma, or the Drepanomonas, or the Cinetochilium...or for that matter the Tetrahymena I hear you cry! The Protist Database does give some guidelines for discriminating amongst these genera - typically discrimination involves carefully noting the position of mouth parts, the presence/absence of any stiffer bristles amongst the more whiskery cilia, or the absence of cilia on some parts of the body - but I confess I've not attempted to apply these to my organism since, firstly, the time commitment, my limited number of specimens and my comparatively humble microscope setup would, I'm sure, limit my chances of a successful identification. Secondly, there exists a nagging worry at the back of my mind that the taxonomy ('family tree') of the protozoa may not in fact be correctly established at this time. Certainly, the arrival of DNA sequencing technology is requiring that large amounts of what was assumed to be true about the inter-relationships of different species in other fields of biology is having to be drastically revised. The problem is that what two species look like is not necessarily a guide to how closely related they really are. DNA testing is revealing that superficially similar organisms can sometimes be only distantly related. The opposite is also true. I wrote about this in detail in my previous posting on the Glistening Inkcap Coprinus mushroom. I have no knowledge of the true status for microscopic cilates but I would not be at all surprised to learn that their taxonomy is also undergoing something of an upheaval amongst the professionals. For this reason also I've not attempted a more detailed identification of my ciliate. Of course, my thinking on all this may be entirely wrong. Perhaps someone looking at my photo's can tell immediately what species I have. If so, and you're that person, do please leave a comment.

Fieldfare Turdus pilaris

I am an amateur naturalist trying to learn something about everything living in my garden.

Happy Christmas!

And what better way to enjoy the day than with a photo of one of my favourite visitors to the British garden: the Fieldfare (Turdus pilaris). Photos 1 and 2 show rear and front views (captured using my home-made camera trap incidentally).

I have an apple tree in my garden, which, besides providing a home for various lichens and mosses (not to mention a resting post for beeflies!) yields a bumper crop of cooking apples. So many in fact that that I have given up trying to collect them all and lots are left to lie on my lawn where they fall. They may look a bit untidy but this is more than made up for by the large numbers of Blackbirds, Fieldfares, Song Thrushes and other birds they attract come winter. In my garden, it is not unusual to find fifty birds at a time feeding upon them .

At 26cm in length and 100g, Fieldfares are a little larger and stockier than Song Thrushes (the BTO site has a host of biometric data). They eat invertebrates and berries (and apples!).
Fieldfares are not really resident in Britain. I say 'not really' since, as I learn from my copy of the RSPB Handbook (Holden and Cleeves) in fact a first British breeding pair was recorded here in the Orkney Isles in 1967. Over subsequent decades the number climbed to a peak of 13, but has since fallen back to less than five pairs a year. Of the population of one million individuals in Britain and Ireland, the overwhelming number are winter migrants, arriving here from late October from Scandinavia and Northern Russia.

Attempting to learn something further about Fieldfares I did a quick internet search and came across an interesting online paper by O. Hogstadt Nest Defence Strategies in the Fieldfare (Ardea 92(1), 79-84) in which the author reports studies of the response of nesting Fieldfares to effigies of crows and stoats - common egg predators of the Fieldfare. The Fieldfare's under study showed a distinct and rather well optimised reaction to these two predators. With crows, the reaction was to try to deter the attackers by defecating on them. This makes sense as fecal matter would certainly be detrimental to the performance of a crow's feathers. With stoats however, the reaction of the Fieldfares was to silently slip away from the nest and delay their return - eminently sensible when faced with a predator that hunts mainly by smell and is an equal danger to eggs and adults alike.

To end why not a few lines of poetry. These from the Cornthwaite by the British poet, Norman Nicholson (1914-1987):

Granite and black pines, where the migrant fieldfare breeds
And the ungregarious, one-flowered cloudberry
Is commoner than the crowding bramble.

A mushroom Psathyrella lutensis

I am an amateur naturalist trying to identify everything living in my garden.

Photo 1 shows a small troop of mushrooms I found growing in some damp grass beneath my garden hedge.
From its general appearance my first thought was that these were a type of ink cap mushroom (see my previous posting here), but after watching them for a week there was no sign of any of the caps dissolving into an inky mess and it was clear further investigation would be needed.

The first thing to do when seeking to identify a mushroom is to take a spore print. This is extremely easy: place a cap, gills down, on any suitable surface, wait twenty minutes, remove, and hey presto - a spore print. That of my mushroom is shown in photo 2. Knowing spore colour (here, black) will typically allow you to rule out at least half the species in the average mushroom guide.

If you have a microscope it can also be valuable to ascertain spore shape and size. Mine were ovoid and around 12x6micron (photo 3).

Other features I noted for my mushroom were the the grooved (the technical term being striate) mostly brown cap, fading to white at the edge, and the 'flakey stem' (a.k.a. floccose stipe) in photo 1.

With these features in mind it was time to turn to the guide books. Unfortunately, such is the number of species of mushroom in Britain (more than 3000, with others, new to these shores, being recorded regularly) that no single guide book can cover them all. This proved the case for my mushroom. I failed to find it in the first three books I tried, the floccose stipe proving a rather troublesome feature, ruling out a number of otherwise similar small brown mushrooms in the books. It wasn't until I turned to my copy of Mushrooms and Toadstools (Cortecuisse and Duhem) that I found a picture of Psathyrella lutesnsis. All the features were there and I'm fairly confident in this indentification.

Cortecuisse describes P. lutensis as growing on damp ground (a fit with my location) and being scare-to-rare.

I have learnt in the course of writing this blog that almost any life form I come across will have some unique and curious aspect to its lifestyle (for example, its relationships with other creatures, its chemistry, or its means of reproduction). No doubt this is true of P.lutensis. Unfortunately my searches have failed to turn up any information about it whatsoever. Perhaps I have merely looked in the wrong places. On the other hand, so sporadic and fleeting may be its appearance that perhaps no one has ever studied my enigmatic little mushroom. If anyone knows more any more about it than merely its name, do please leave a comment.

Gooseberry sawfly Nematus ribesii

I am an amateur naturalist trying to learn something about everything living in my garden.

I have a Gooseberry bush in my garden. In previous years I've had a good berry crop. But not this year! In May something attacked the bush, totally stripping the leaves. The culprit is shown in photo 1.

From closely similar photo's on the web I'm fairly confident this is the larva of the Gooseberry sawfly (Nematus ribesii). I should add my customary 'health warning' however: I'm not an expert on plant pests. As an amateur, you quickly learn that in natural history, identification of insects (fungi, spiders, lichen etc. etc.) solely on the basis of a photograph is always risky. There are more than a dozen species in the Nematus genus for example (see Bioimages site). I've found photos of only a handful. My caterpillar certainly looks like N.ribesii, but I don't know for certain it isn't one of the others. Can anyone more expert comment?

The damage done to my poor Gooseberry bush is shown in Photo 2. The branches would normally have been covered in leaves at this point in the year.

I did not spot any adult N. ribesii. From the photo's on Faroe Nature however it would appear they are squat, orange insects. This site has a drawing of the wing veinature taken from the book 'The Wings of Insects' (J.H. Comstock, 1918). (Wing veins are an important guide to insect identification - see my posting here).

In searching for articles on my sawfly I came across the admirable site of the Journal of Cell Science. This carries a large, searchable database of freely downloadable scientific papers. My searches turned up three on gooseberry sawflies (L. Doncaster, 1907, L. Doncaster 1905 and S. Shafiq, 1954). All get rather technical in places and I don't pretend to have followed all the details. From a quick read however, an interesting snippet I picked up is that eggs from both fertilised and unfertilised N. ribesii females can hatch but that larvae hatching from unfertilised eggs are overwhelmingly male. Eggs are laid in rows on the lower side of leaves at intervals of about a minute incidentally.

The main topic of the papers above relates to embryogensis i.e. the truly miraculous feat that Mother Nature manages of beginning with a single cell (an egg) and by a processes of repeated cell-replication and inter-cell communication constructs a complete insect (say) comprising hundreds-of-thousands of cells of countless types, all located in the right places, and all in an incredibly short period of time (about 4 days in the case of N. ribesii). Trying to undestand how she does this remains one of the great challenges for modern bioscience. It is perhaps fitting for this posting, that one of the most intensely studied creatures in all of science is a fruit fly (Drosophila melanogaster), flies being an ideal test-animal for such studies (along with nematode worms - see my post here) since dozens can be kept in a test tube where they will breed copiously and the offspring hatch rapidly. Armies of biologists have published innumerable articles about D. melanogaster - this site gives a flavour.

So there you have it, a seemingly humble garden pest with a rich natural history. Mind you, it might have been nice to have had a gooseberry crumble this year!

A macrochelidae mite

I am an amateur naturalist trying to identify everything living in my garden.

On a whim, I recently got out my trusty Baermann funnel (which sounds far more technical than it actually is, namely, a sieve for sieving tiny critters out of soil) and was pleased to discover a host of new-for-my-blog creatures in a handful of old grass clippings. One, a mite, is shown in Photo 1 (click on photo's to enlarge)

Readers of my blog will know I make some effort to research the species of any creature I find in my garden. In the case of my mite however, this turned out to be no small challenge. Before this posting I knew nothing about mites. As I discovered, there are at least three factors mitigating against the amateur seeking to identify one to species level.

Firstly, there is the obvious minute size of mites' physical features. Identification to species can depend on close examination of some minute gland on the body or joint in the jaw-parts ('chelicerae'). With only one specimen and the type of microscope equipment typically available to the amateur, such features can be a challenge to view. The professional may perhaps turn to an extensive university collection of carefully dissected and permanently mounted specimens or examine their find by electron microscope. Sadly however, I don't have a electron microscope in my garden shed (I'm open to donations!).

A second challenge is the sheer number of mite species. More than 45,000 (here) have been recorded and some sources estimate this may be only 5% of the number awaiting discovery. To make matters worse there seems to be a dearth of elementary texts or online keys in the area. A number of advanced texts are available (at suitably advanced cost!) but there seems to be little along the lines of a field guide aimed at the amateur (I'd be pleased to be corrected on this matter).

Attempting to work through academic journal papers and keys brings one to a third difficulty, namely the dense jargon that accompanies the study of mites (acarology). The amateur must wrestle with references to such arcane structures as pretarsal condylophores, filiform corniculae and Claperede's organs. To complicate matters still further, acaralogists refer to the hairs (setae) that decorate mites' bodies in code ('h1', 'pg3' etc.) and not only does there seem to be no simple online explanation of how this code works (anyone?) but there is more than one system in use amongst the professionals.

Thankfully however, there are some notable exceptions to the comments above. On his excellent web site David Walter Evans has put together a Glossary of Acarine Terms, indispensable for making sense of the jargon of acarology. For discussion of some current research topics in acarology and some superb images see Macromite's blog. My searches turned up very few online keys but notable exceptions are the one on David Evans' site above and the interactive key here on the site of the North American Bee-Associated Mites project.

It was the latter that enabled me to make some progress with my mite. I spent some time inputting various features into the key with limited success, but then noticed my mite had 'brush like arthropodrial processes on the chelicerae' (in English: a fringe of hairs on its pincer-like mouthparts). You can see these in photo 2. In the key above this immediately narrows things down from my mite being in any of 36 possible families, to it being in the single family macrochelidae. (As always my identifications come with a health warning - I'm happy for them to be corrected)

Unfortunately that is as far as the key takes me and from the webpages of Dr G.W. Krantz I learn there are still well over a hundred individual species in the macrochelidae family. The book to consult would appear to be A Review of the Macrochelidae of the British Isles by Hyatt and Emberson, but this is out of print and seems generally unavailable.

In the course of my searches I pleased to discover that I am not the only UK amateur taking an interest in the fauna beneath our feet. Over at Alan Hadly's splendid site he too is busy studying macrochelidae mites (together with a host of other critters).

I must end this posting here. My intention in writing my blog is to learn something of the natural history of the creatures I encounter. It may not have escaped the attention of the observant reader however, that in this article I have largely failed to say anything about the natural history of mites. I feel relaxed! With 44,999+ species potentially still at large in my garden, I suspect this will not be the last time I have an opportunity to study these tiny creatures...

Dasineura urticae galls on a nettle leaf

I am an amateur naturalist trying to learn something about everything living in my garden.

I've previously blogged the nettles (Dioica urticae) growing in my garden (indeed, I guess some of you reading this may even now be tucked up in your nettle bed sheets!) and also described some of the capsid bugs (Liocoris tripustulatis) I found living on them.

Recently I've noticed evidence of a second lifeform feeding off my nettles, namely the galls in photo 1.

I am fortunate enough to be in possession of a set of a dozen-or-so volumes of Field Studies, a journal that was at one time published by the Field Studies Council. This admirable UK charity runs a wide range of residential study courses aimed at the amateur naturalist. The Field Studies journal is no longer printed which is a pity as it commonly used to feature keys for the amateur wanting to identify some of the trickier plants and animal in our fields and gardens, including (for present purposes) a key to British Plant Galls by Redfern, Shirley and Bloxham in the October 2002 issue. Fortunately, for those of you without old copies of the journal to hand, this key has been reprinted. You can purchase a copy along with various other gall guides from the British Plant Gall society here.

Redfern, Shirely and Bloxham list five arthropods and one fungal rust capable of causing galls on British nettles. The pouch-like swellings with slit-like grooves in their surfaces on the leaf in photo 1 indicate these are galls caused by the small fly, Dasineura urticae. Had I cut open some of the galls (I didn't) I might have been lucky enough to find some of the white grubs of this fly. Indeed, as I learnt from the very nice 'A Nature Observer's Scrapbook' site, I might even have found some predatory grubs from another species, laid there to eat the Dasineura urticae grubs.

I'm very far from being an expert in diptera (flies). From the Bioimages site however it seems there are several dozen British species in the fly genus Dasineura. This site has pictures of the grubs and galls of some of them.

I have only found one description of an adult D.urticae fly: My copy of Insects on Nettles (Davis, Richmond Publishing) describes a "very small fly with long antenna. Under a microscope an antenna looks like a string of beads...". Unfortunately I haven't been able to find a photograph on the web, although the Bioimages site does carry a photo of another Dasineura species (D. sisymbrii) which I guess may be rather similar since it too has bead-like antenna.

Sadly, that is as much as I have managed to learn about my mysterious fly. How and when the adults mate, how a female locates a host patch of nettles, whether she lays eggs or live grubs, how long the grubs remain inside their gall... I can only guess at the answers to these and a host of other questions. Another garden study-project to add to my burgeoning list!

A Blood-Vein Moth (Timandra comae)

I am an amateur naturalist trying to discover everything living in my garden.

What with photography, microscopy and literature searching, my self-imposed mission to catalogue my garden's life places lots of demands on my free-time. When I've a chance however I'm still making an effort to set out my home-made moth trap at night. I did so recently (on the 22nd August for the record) and it yielded a good haul of new species to add to my garden list, amongst them the attractive moth in photo 1.

My moth's common name is The Blood-Vein, for reasons that I imagine are obvious. It is a member of the large (several hundred species in the UK) geometridae family of moths, so called because of the caterpillars of these moths walk with a measuring (=hence 'geometer'), 'inch-worm'-like, gait.

From my copy of Moths of Great Britain and Ireland (Townsend and Lewington) I understand Blood Vein caterpillars feed on dock, sorrel, knotgrass and common orache. I've not been able to find a picture of one on the web (anyone?). Price, Goldstein and Smith studied the suitability of the Blood Vein for introduction into the States as a biological control agent against 'Mile a Minute' Weed (their paper is available here). (They found it was unsuitable)

Adult Blood Vein's are fairly common in Mid- and Southern Britain, but get rarer in the North.

The Blood Vein gets but a single mention in my copy of the excellent Moths (Michael Majerus). One might expect that such small and fragile creatures as moths might tend not to fly about in severe weather such as during heavy downpours. Surprisingly this seems not to be the case however: Majerus reports setting up a moth trap during a severe thunderstorm and trapping several hundred moths, undaunted by the driving rain, within hours. A dozen or so Blood Veins were among them.

The Blood Vein's scientific name is Timandra comae. There seems to be some confusion over the the relationship between this moth and the closely similar Timandra griseata. At various times the two have been lumped together as a single species, and at other times split out as two. Current work suggests they are indeed two separate species.

In Greek mythology Timandra was one of the daughters of the Spartan King Tyndareus and his wife Leda (she of swan-fame). Timandra's sister was Helen of Troy. King Tyndareus managed to upset the goddess Aphrodite and was punished with a curse that all his daughters would be adulteresses. Daughter Timandra duly obliged, eventually marrying one King Echemus only to later desert him for King Phyleus.

Now, whether in fact my moth has a particularly adulteress streak to its nature I really can't say. Indeed, aside from the snippets of information above, I've been failed to find any significant written accounts of the biology and behaviour of The Blood Vein. Whether this is because I've not looked in the right places, or whether it is that The Blood Vein, in common with so many other insect species, has simply not been studied in detail, I do not know. I'd be delighted to find out a little more about this pretty moth however, so do leave a comment if you can help.