From apoda to myriapoda

(This post is the last of four about the numbers of legs and toes in the animal kingdom. If you missed the first one, on mammals, you might want to look at it because it explains why I have chosen this theme. It was posted on June 29th: https://wp.me/p90hhh-Dq )

Invertebrates are thought to have developed limbs completely independently from vertebrates, and the details of their morphology are quite different. So instead of counting fingers and toes, I shall count (mainly) legs, and my examples are in order of increasing leg count.

At the minimist end are creatures like leeches, that have no feet, i.e. they are apodal. This one was from a pond in Maine, and is probably parasitic on turtles.

Leech or flatworm, Heald Pond, July 2013. One inch?

Moving onward and upward, we leap to the grasshopper. Like all true insects, it has six legs, and the last pair are the real powerhouse: look at those quads (or at least that’s what we’d call them in a human):

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On the end of each leg, and on some joints,  are two tiny claws to help him hang on. In addition to six legs, they have two pairs of wings, and two antennae, for a grand total of twelve appendages.

Spiders are of course not insects, but arachnids, and they have eight legs:

Orb-weaver Spider

Each leg ends in a  tarsal segment, from which grow three tiny pincers that the orb-weaving spider uses with great precision to create its web. (Hunting spiders have only two claws.)  Spiders also have two more shorter appendages called pedipalps, visible in the photo, which are used for sensing, digging, and sometimes copulating, so in fact they have a total of ten appendages!

Caterpillars are the larvae of butterflies and moths, which are themselves insects, so like the grasshopper they have three pairs of legs at the front emerging from what will become the butterfly’s thorax, but they also have four pairs of prolegs in the middle on their abdomen, and one pair at the back called claspers. These extra ten legs are cylindrical.

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They have a set of microscopic hooks on the base. The impressive total is thus 16 legs, giving me an excuse to use the word hexadecapodal.

The winners in the leg count stakes are the myriapods (another great word/world), a group that includes both millipedes and centipedes.  I photographed these in Ecuador. They are millipedes, with two pairs of legs on the majority of segments, and this order, Polydesmida, usually has 20 segments. The “leggiest” millipedes, however, can have up to 192 segments and 750 legs!

Millipedes mating

The internet is a wonderful thing. In an attempt to work out what this group of four poisonous millipedes was up to, I emailed Rick Brusca at the U. of Arizona, who said “I am not a myriapodologist” (best word of the day) and passed me on to Allessandro Minelli at the University of Padova, who in turn passed me on to Sergei Golovatch of the Russian Academy of Sciences. The generosity of this chain of scholars, all strangers to me, produced a detailed reply in perfect English within less than 24 hours.

“Dear friends,
The picture of the milllipede from Ecuador definitely shows a species (gen. sp.) of the HUGE family Chelodesmidae (order Polydesmida, class Diplopoda). The bright blue colouration is unusual, more characteristic of a different, purely Central American family, but the few somatic characters I can trace are chelodesmid ones without any doubt. The distributions of numerous Polydesmida are aggregate, but whether it involves courtship or not, remains unknown (at least to me). I doubt it, being rather inclined to think that aggregations better protect. The aposematic colouration* seems to favour this assumption as well. Like most larger Polydesmida, Chelodesmidae (basically Neotropical and Afrotropical), are also poisonous (cyanide producers) and STINK almond when touched…
I hope this short account helps.
Best regards, Yours cordially Sergei”

(*’aposematic colouration’ warns predators that the animal is toxic. I was not tempted to touch them, so I can’t vouch for the almond stink!)

For a final flourish, how about this chap in a cave in Borneo? I counted 64 legs, but Sandro Minelli has better eyes, and says there are 32, each with its own shadow, and that two are antennae, not legs.

Long-legged centipede, a cave-dweller

Both Sandro Minelli and Sergei Golovatch tell me it is a Thereuonema sp. (family Scutigeridae, order Scutigeromorpha, Class Chilopoda), common in Southeast Asia. It is a large and extremely swift predator, a distant relative of similarly frightful and much better known scolopendras. Thank you both.

For astonishing insect close-ups, including feet, look at these: https://www.levonbiss.com

 

 

“..toe of frog….lizard’s leg..”*

(This post is the third of four about the numbers of legs and toes in the animal kingdom. If you missed the first one, on mammals, you might want to look at it because it explains why I have chosen this theme. It was posted on June 29th: https://wp.me/p90hhh-Dq )

Today I’ll look at lizards, frogs, and turtles. But let me dispose of the toeless snakes first: here is a harmless and burnished Eastern Corn Snake, photographed in a parking lot in Vero Beach, Florida

Eastern Corn Snake

Lizards have five toes on all their feet. This is a carnivorous monitor lizard:

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And an insectivorous gecko, whose toe-pads have bristles like Velcro to help him climb walls. He can hold onto anything except Teflon!

Bibron's Gecko

Caimans and other crocodilians have five toes on their front feet and four on their back feet. There is only one way to photograph the soles of a caiman’s feet; look away now if you are squeamish. The (ex) caiman’s tail is towards the camera.

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In chameleons, these five toes are reduced to two (a group of two and a group of three, each grouping swaddled in skin). This photo was taken in Rwanda, where the local people think chameleons are bad luck:

The Malagasy think chameleons are evil spirits

Turtles mostly have five toes on each foot. This is a Painted Turtle, from Maine, facing right:

Painted Turtles

Frogs have four toes on their front feet and five on their back feet. Both frog species below are tree frogs (because the feet of aquatic frogs are virtually impossible to photograph, being underwater most of the time!). Being tree frogs, they have large sticky toe pads to help them grip. Frogs have an annoying tendency to squat on their back feet in a sort of yoga “child’s pose”, so I failed to find a single photo clearly showing a hind-foot toe count!

Spring Peeper, Maine
Spring Peeper, Maine
Tree frog
Gray Tree Frog, Maine

Frogs don’t have usually have claws, but some African frogs have evolved a bizarre mechanism. When threatened, the tip of their toe bone (phalanx) breaks through the skin and acts as a vicious claw! See Blackburn et al 2008, here: https://doi.org/10.1098/rsbl.2008.0219  who say ” these are the only vertebrate claws known to pierce their way to functionality” .

When the excellent website Amphibia Web  https://amphibiaweb.org celebrated the inclusion of their 7000th species, they celebrated with this song, and even though for some incomprehensible reason it doesn’t even mention toes, it is irresistible:

Next time is my last post on appendages, finally moving away from vertebrates to invertebrates.

* An obvious title for this post:

2nd Witch:
“Eye of newt, and toe of frog,
Wool of bat, and tongue of dog,
Adder’s fork, and blind-worm’s sting,
Lizard’s leg, and howlet’s wing,–
For a charm of powerful trouble,
Like a hell-broth boil and bubble.”

Macbeth (IV, i, 14-15)

The bird with no feet sleeps on the wind*

(This post is the second of four about the numbers of legs and toes in the animal kingdom. If you missed the first one, on mammals, you might want to look at it because it explains why I have chosen this theme. It was posted on June 29th: https://wp.me/p90hhh-Dq )

In flight, you can often imagine that a soaring bird has no feet, and never touches down to earth. Witness this Namibian Augur Buzzard.

Buzzard

But all birds have feet, and most of those feet have four toes, three pointing forward and one at the back. They work extremely well for perching on twigs, like this cardinal:

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The same toe-count can be adapted to spread the birds weight when walking on tricky surfaces like lily-pads or mud. This Grey-necked Wood Rail in the Pantanal has caught a fish, but a moment later its catch was stolen by a large tegu lizard:

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The toes can be webbed for paddling, like the three front toes of this swan. Note the small fourth back toe.

swan

Or toes can be lobed, like this male coot’s, upended by his rival in a vicious kick-boxing match:

Coots

These curious lobes create brilliantly multipurpose feet. In the water, the lobes act like webbing to help with swimming. But on land, when the coot lifts its feet the lobes fold back, making walking through mud easier.

A few birds, including woodpeckers, owls, and parrots, arrange their four toes with two forwards and two backwards. This Hyacinth Macaw is showing the two front toes of each foot:

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Here is a close up of the foot of a barred owl, sadly found dead by the roadside in Maine:

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The ostrich is the only bird with just two toes on each foot:

Male ostrich and chicks; female was also nearby.

Just like zebras and horses, with their single toe, the adult ostrich can kick powerfully enough to kill a man or a lion, and just like in humans the innermost toe is the bigger one! (The front foot is the left foot in the rather confusing photo below.)

Somali Ostrich

There may be money to be made in offering pedicures to ostriches…

I’ll keep following this digital count, with reptiles and amphibians next.

* My title is an oblique reference to this passage from Tennessee Williams:

http://www.undiscoveredearth.com/2011/08/15/excerpt-orpheus-descending-tennessee-williams/

The Pobble who has no toes

I read with fascination this week that the genes in charge of growing appendages (arms, legs, fingers, toes, wings,  tentacles…) are now thought to predate the point at which our lineage diverged from that of the octopus. This is despite the fact that octopi, insects, and vertebrates each evolved their very different limbs independently. The same gene determines the number of fingers we have, and the number of suckers an octopus has, and Martin Cohn and his colleagues have now shown that this genetic program dates back at least 500 million years.*

This article inspired me to take a close look at fingers and toes. It turned out to be quite hard to find good photos in my archives: most of the time animals stand in long grass, or in muddy water, hiding their feet, but here goes. (None of these posts pretends to be a full scientific survey: the limiting factor is what I have photos of.)

I think I’ll start with us mammals. Unlike the Pobble, they all have toes, but the number of toes varies from six to one….

Mountain gorillas, not surprisingly, have the the same number of fingers and toes as us:

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Giant otters also have five toes on each foot, but they are webbed:

Evening grooming sessions, in next few shots and videos

Elephants have five toes, but they walk on tiptoe, so the toe nails are the only way to count.  Like pandas, they have a sixth “toe”. It is inside their foot, and it may help distribute their weight better.

Elephant naptime

Lions, and other cats, have five front toes and four back ones. Here are the five:

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and here are the four:

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Hippos have four webbed toes on each foot, supporting their enormous weight (you can’t see the fourth toe in the photo):

Hippos

Warthogs, like all pigs, have four toes on each foot but they walk only on the middle two, holding the others clear of the ground, for all the world like a ballerina en pointe. (At speed, these smaller claws may touch the ground. ) So really they have two proper toes.

Common warthogs,mother and baby, with Red-billed Oxpecker

All tapirs, including this South American one in the Pantanal, have four front toes and three back ones. They are the only hoofed animal like this.

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Rhinoceri have three toes on each foot:

Indian one-horned rhino

Giraffe (and cattle and deer) have two toes, and the dew claws are insignificant:

Giraffe

Zebras, and all equines, have all five digits merged into one toe (aka hoof) per foot:

Young male zebra playing

It’s also worth remembering that our bodies are left-right symmetrical, so our big toes are on the inside of each foot. Our development thus has not just to get the count right, but arrange each foot appropriately for which side of the body it emerges from. How clever is that?

Next time, we’ll look at birds.

‘The Pobble Who Has No Toes’

The Pobble who has no toes
Had once as many as we;
When they said "Some day you may lose them all;"
He replied "Fish, fiddle-de-dee!"
And his Aunt Jobiska made him drink
Lavender water tinged with pink,
For she said "The World in general knows
There's nothing so good for a Pobble's toes!"

The Pobble who has no toes
Swam across the Bristol Channel;
But before he set out he wrapped his nose
In a piece of scarlet flannel.
For his Aunt Jobiska said "No harm
Can come to his toes if his nose is warm;
And it's perfectly known that a Pobble's toes
Are safe, -- provided he minds his nose!"

The Pobble swam fast and well,
And when boats or ships came near him,
He tinkledy-blinkledy-winkled a bell,
So that all the world could hear him.
And all the Sailors and Admirals cried,
When they saw him nearing the further side -
"He has gone to fish for his Aunt Jobiska's
Runcible Cat with crimson whiskers!"

But before he touched the shore,
The shore of the Bristol Channel,
A sea-green porpoise carried away
His wrapper of scarlet flannel.
And when he came to observe his feet,
Formerly garnished with toes so neat,
His face at once became forlorn,
On perceiving that all his toes were gone!

And nobody ever knew,
From that dark day to the present,
Whoso had taken the Pobble's toes,
In a manner so far from pleasant.
Whether the shrimps, or crawfish grey,
Or crafty Mermaids stole them away -
Nobody knew: and nobody knows
How the Pobble was robbed of his twice five toes!

The Pobble who has no toes
Was placed in a friendly Bark,
And they rowed him back, and carried him up
To his Aunt Jobiska's Park.
And she made him a feast at his earnest wish
Of eggs and buttercups fried with fish, -
And she said "It's a fact the whole world knows,
That Pobbles are happier without their toes!"

Edward Lear

 

*Here is a short summary of Martin Cohn’s findings:

https://www.nature.com/articles/d41586-019-01829-9?utm_source=Nature+Briefing&utm_campaign=2f9e8c8999-briefing-dy-20190621&utm_medium=email&utm_term=0_c9dfd39373-2f9e8c8999-44042041

 

 

 

 

 

 

 

 

Nature’s bride-tossed bouquet*

On the marshes in Aldeburgh in Suffolk there was a solitary tree-sized elder, full of small birds. A single twig reached leftwards against the sky, and provided a convenient perch for a just-fledged bluetit chick:

Juvenile blue tits

Last weekend the elderflowers (Sambucus nigra) were still in full bloom in the hedgerows:

elderflower

Close up, the flowerheads are exquisite:

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A sedge warbler posed on the same elder-twig:

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In Sussex, in the elder-bordered fields, I found these exquisite flowers. I doubt if many of you can guess what they are?

Dock flowers

They are the flowers of dock plants, Rumex obtusifolius. They are no-one’s favorite: scruffy, hard to eradicate weeds, with tall skinny greenish-brownish flowerheads covered in minute unimpressive flowers that we rarely stop to admire. The flowers redden as they mature into these miniature bells. No-one writes poems about dock flowers, but next time, look closely.

In England of course, we pick the elderflowers for elderflower cordial, delicious drunk on its own or with champagne. Here is Jamie Oliver’s recipe:

https://www.jamieoliver.com/features/how-to-make-elderflower-cordial/

* My title comes from the first verse of a poem by Malachy Reynolds,  The Elderflower’s Lament. 

I am the elderflower
Wedded to the hedgerows
Nature’s bride-tossed bouquet.
Not gaudy like the rose….

Follow him on Twitter here: https://twitter.com/MalachyReynolds

 

 

The dandelion deserves its close-up too

Here is a common dandelion, Taraxacum officinale. Boring!

DSC09930

But the wasp does not agree. She is busily foraging for nectar, deep inside the 200-odd tiny florets that compose the flower-head.

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The tall curly things are the stigmas, covered in pollen:DSC09930-2

and the pollen collects on the body of the wasp, who then unwittingly transfers it to the next flower that she visits:

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Successful pollination means the dandelion can produce its plumed seeds, each called a pappus, to create that ethereal thing, the dandelion clock:

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A single pappus can be seen top left, detaching itself from the seedhead. The word ‘pappus’ is from the Greek for grandfather, whose white beard the dandelion clock resembles. A pappus can fly for a kilometre, and scientists have worked out how they do it:

https://www.insidescience.org/news/how-dandelion-seeds-stay-afloat-so-long

The much smaller coltsfoot is being visited here by a flower beetle. Just like the dandelion, the coltsfoot’s curly stigmas will deposit their pollen on the insect, though I must admit his shiny wing cases don’t seem likely to provide a very good attachment site:

coltsfoot? flower beetle?

Below is a link to a really wonderful piece by Brian Johnston with microscopic photos of the dandelion, showing far more than I can manage with my camera.

http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artjun10/bj-dandelion.html

And I had completely forgotten that my friend Leigh Hayes did a terrific post on dandelions two years ago. Here it is: https://wondermyway.com/2015/05/17/never-call-it-just-a-dandelion/

And do consider following her blog too.

“Sumer is icumen in”*

Since 1970, English farmland birds have declined by 54%. Since 1976, butterflies have declined by 41%. Overall, 12% of farmland species are at risk of extinction. We need to value and fight for what remains. Look carefully, and you will be rewarded still.

When the hares were being elusive, I dawdled, and enjoyed anything that came my way. Most local farmers set aside strips of uncultivated ground alongside their crops, and together with traditional copses these at least provide small havens for small wondiers.

Two baby Blue Tits (sorry about the focus):

Juvenile blue tits

Wildflowers and their attendant pollinators:

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A browsing deer:

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An insect licking moisture from a leaf:

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A Spotted Orchid:

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A Long-tailed Tit:

Long-tailed tit

A Common Blue butterfly with its slender coiled black tongue just visible:

Female Common Blue

And a mystery seedpod, near the stream, fallen from somewhere: does anyone know what it is?

?plantain seeds??

There is still much left to marvel at even in heavily farmed agricultural land in the 21st century, though this 2016 report makes for depressing reading:

http://ww2.rspb.org.uk/Images/State%20of%20Nature%20UK%20report_%2020%20Sept_tcm9-424984.pdf

*But beauty remains. Eight hundred years ago, an anonymous poet said it all (modern version below!):

Sumer is icumen in,
Lhude sing cuccu!
Groweþ sed and bloweþ med
And springþ þe wde nu,
Sing cuccu!

Awe bleteþ after lomb,
Lhouþ after calue cu.
Bulluc sterteþ, bucke uerteþ,
Murie sing cuccu!
Cuccu, cuccu, wel singes þu cuccu;
Ne swik þu nauer nu.

Sing cuccu nu. Sing cuccu.
Sing cuccu. Sing cuccu nu!

And in modern English:

Summer has come in,
Loudly sing, Cuckoo!
The seed grows and the meadow blooms
And the wood springs anew,
Sing, Cuckoo!

The ewe bleats after the lamb
The cow lows after the calf.
The bullock stirs, the stag farts,
Merrily sing, Cuckoo!
Cuckoo, cuckoo, well you sing, cuckoo;
Don’t ever you stop now,

Sing cuckoo now. Sing, Cuckoo.
Sing Cuckoo. Sing cuckoo now!

Apparently ‘uerteþ’ (or ‘verteth’) can mean either ‘cavort’ or ‘fart’!