Almost mammals

A female ball blattodean (Perisphaerus lunatus) from northern Cambodia begins to unfurl to reveal long, powerful legs.

A female ball blattodean (Perisphaerus semilunatus) from northern Cambodia begins to unfurl to reveal long, powerful legs.

I was rummaging one day through the leaf litter on the forest floor in northern Cambodia, looking for insects, when a small, perfectly round ball rolled from a leaf above, bounced off my head, and landed on the ground in front of me. I picked it up to have a closer look, not sure if the object was an animal or a plant. It was about the size of a pea, but black, and very hard. It was an animal, as betrayed by the clearly visible segmentation of its body, but several groups (crustaceans, millipedes, and armadillos, to name a few) use a very similar tactic, and I was not sure which one I was holding (I quickly ruled out armadillos.) After a few seconds a pair of big eyes with two short antennae between them cautiously peeked from a crack that opened on the mysterious sphere. It was a blattodean, but one I had never seen before. Later I identified it as the ball blattodean (Perisphaerus), an interesting animal that experiments revealed to be, thanks to its tight armor, virtually impervious to attacks by ants and other small predators. In fact, the combination of the hard cuticle that forms its exoskeleton with its powerful muscles makes it impossible to unroll the animal without damaging it.

Ball blattodeans of the genus Perisphaerus and several related genera are probably the only organisms other than mammals that exhibit suckling behavior. Young nymphs of these insects have long, almost proboscis-like mouthparts that allow them to access a series of special “mammary” glands on their mother’s underside and suck nutritious fluids.

Ball blattodeans of the genus Perisphaerus and several related genera are probably the only organisms other than mammals that exhibit suckling behavior. Young nymphs of these insects have long, almost proboscis-like mouthparts that allow them to access a series of special “mammary” glands on their mother’s underside and suck nutritious fluids.

Rolling your body into a tight, hard ball is a neat trick, perfected by only a few other insects, but there is something else about Perisphaerus that makes it unique among not only insects, but also almost all other animals. Blattodeans, a large, ancient lineage, represented by nearly 5,000 species, is a truly fascinating example of the evolution of parental care and social behavior. Within insects, where good parenting usually amounts to not eating your young, blattodeans display levels of devotion and parental sophistication otherwise found only in birds and mammals. Dr. Louis M. Roth, the late Harvard entomologist who during his long and productive life uncovered many secrets of blattodean biology, was the first to realize the unusual nature of Perisphaerus. While studying these insects he noticed that females were often accompanied by nymphs clinging to their legs, and some of these youngsters had their heads stuck to the underside of their mother’s body. Careful examination revealed something strange – the mouthparts of the nymphs were very long, almost proboscis-like, a trait unknown in blattodeans, whose mouthparts are of a simple, biting type. Looking carefully at the female Roth also noticed that between the bases of her legs were small, glandular openings, and that’s where the young ones were sticking their heads. Could it be that the mother were actually suckling her young? Up to that point only mammals were known to display this type of behavior, but suddenly it appeared that a similar one might have evolved at least one more time in the history of the animal kingdom. The evidence for this is still largely circumstantial, but what we know about blattodeans certainly supports such a possibility. Many species of these insects give birth to live young, and in a few cases the female feeds them until they are ready to start foraging on their own. In the case of the Pacific blattodean (Diploptera punctata) the female develops an equivalent of the mammalian placenta, and feeds the embryos growing inside her abdomen with a rich mix of proteins, lipids, and carbohydrates. But a female with “mammary glands” and nymphs with sucking mouthparts take the maternal care among blattodeans to a completely new level.

North American forest blattodean (Parcoblatta penssylvanica) carrying an ootheca – a hard, nearly indestructible purse that protects the eggs from predators, parasitoids, and desiccation.

North American forest blattodean (Parcoblatta penssylvanica) carrying an ootheca – a hard, nearly indestructible purse that protects the eggs from predators, parasitoids, and desiccation.

A couple of years after my first encounter with Perisphaerus I found myself, in the middle of the night, following through a bamboo thicket a group of fanatical herpetologists who were intent on catching a particularly elusive, possibly new to science frog. We were in New Britain, a large island that is a part of Papua New Guinea, and I knew that I had a good chance to run across Perisphaerus again. Sure enough, the very moment I heard a triumphant scream that announced the capture of the unfortunate amphibian, I saw the mysterious blattodean scurrying around my feet. And it was a pregnant female. She gave birth to about 10 young a few days later, and during the two weeks when I kept her in a small container the nymphs always stayed with her, hidden under her body, their mouthparts firmly between her legs. Every now and then she would have a bite of a fruit, but the young ones never left her side or fed independently. And yet they grew. I separated a couple of nymphs from their mother and offered them the same conditions and food I was providing her with – they were dead within three days, while their siblings continued to thrive. This short observation convinced me that the female feeds her young with something secreted by her body, and that they completely depended on it, just like mammalian offspring does. My admiration for insects ratcheted up yet another notch.

Table Mountain blattodean (Aptera fusca) from South Africa is a species that exhibits an extended maternal care.

Table Mountain blattodean (Aptera fusca) from South Africa is a species that exhibits an extended maternal care.

Of course, not all blattodeans display the same degree of nurturing and maternal sacrifice, but there is not a single species in this group that does not at least try to give its children a safe start in life. The least the female blattodean can, and most do for their eggs is to encase them in a hard, chitinous purse that protects the eggs not only from physical injuries and desiccation, but also creates a very effective barrier to predators and parasitoids. Usually such a container, known as the ootheca, is carried by the female until the eggs are almost ready to hatch. She will then burry or glue it close to the source of food, usually a fruit or some particularly tasty leaf, and the young hatch a few days or weeks later, ready to start independent life. In more advanced species the female never lets her eggs go, and while she still protects them in an ootheca, she carries it until the very day the young ones are going to hatch. Others take it a step further and, after forming the ootheca and filling it with eggs, suck it back into their abdomen. There, protected by both the ootheca and their mother’s belly the young ones complete their development. Their hatching takes place inside the mother’s abdomen, giving the impression of live birth (such false live birth is known as ovoviviparity.) And finally, there are species, such as the Pacific Diploptera punctata that are truly live bearing.

A large, shield-like pronotum protects the head and front legs of the giant blattodean (Blaberus giganteus) from Guyana.

A large, shield-like pronotum protects the head and front legs of the giant blattodean (Blaberus giganteus) from Guyana. This species is ovoviviparous, which means that eggs are carried by the mother until they are ready to hatch and the nymphs are ready to start independent life.

I have always been fascinated by these animals: the simple elegance of their bodies, their devotion as parents, their dominance in tropical ecosystems, their ancient origin, all this made me want to learn more. But for a group so rich in species and so abundant in many terrestrial ecosystems, we know shockingly little about blattodeans. There are probably no more than 20-30 scientists worldwide who study the 5 thousand or so species we already know about (an equal number of new species of blattodeans most likely still awaits discovery.) At the same time thousands of students and researchers around the world work on mammals, a group with a comparable number of species. As it turns out, the two may have a number of astonishing similarities in their reproductive behavior. Perhaps some of the mammal specialists could be enticed to broaden their taxonomic horizons, and help us learn more about one of the most intriguing groups of animals that ever walked the Earth? Entomologists could really use some help here.

Wood blattodeans (Cryptocercus) took their family life to the next level, and these insects live in small, multi-generational societies. Females feed their offspring symbiotic protozoans, which these insects need to be able to digest cellulose, their main source of food. From here it took only a small evolutionary step towards eusociality, which we see in a lineage of blattodeans known as termites.

Wood blattodeans (Cryptocercus) took their family life to the next level, and these insects live in small, multi-generational societies. Females feed their offspring symbiotic protozoans, which these insects need to be able to digest cellulose, their main source of food. From here it took only a small evolutionary step towards eusociality, which we see in a lineage of blattodeans known as termites.

Mozambique Diary: Shooting bats

Leaf-nosed bats (Hipposideros sp.) in a cave of Cheringoma Plateau, Gorongosa National Park.

Leaf-nosed bats (Hipposideros sp.) in a cave of Cheringoma Plateau, Gorongosa National Park.

My entire last month was a blur of hectic activity, related mostly to the opening of the E.O. Wilson Biodiversity Laboratory in Gorongosa National Park. This kept me from updating the blog, but it was definitely worth it – the Lab is a fantastic facility that will serve as a research base to current and future scientists in the park, and as a center of advanced biodiversity education for Mozambican students for years to come (I just finished teaching its first African entomology workshop there, and it was great.) We are also creating the Gorongosa Synoptic Collection, which has the ambitious goal of documenting, over the next 15-20 years, all (or at least as much as physically possible) multicellular diversity of the park – I will try to post frequent updates from this effort. In the meantime, I would like to invite all biologists to come and work in Gorongosa – there is an entire universe of unexplored life out there, waiting to be studied and saved. Contact me if you are interested – Gorongosa wants your research projects, and we will help you make them happen.

Slit-faced bat (Nycteris cf. thebaica) from Gorongosa and a sonogram of its echolocation.

Slit-faced bat (Nycteris cf. thebaica) from Gorongosa and a sonogram of its echolocation.

One of the many benefits of having a permanent and safe logistical base in a place as biologically rich as Gorongosa is that I am not afraid to bring and leave behind my expensive high tech gear, and experiment with it. For months I had been dying to try out my high speed photography system, and finally was able to use it last month to shoot flying bats in the comfort of our lab. Now, bats have been photographed in flight by many, and the technology to do so has existed since at least the 1980’s. But, as far as I could tell, few had tried to take images of flying bats using the white background technique, made popular by the Meet Your Neighbours project, and I really wanted to try it.

An orange form of a Horseshoe bat (Rhinolophus landeri) from Gorongosa and a sonogram of its echolocation.

An orange form of the Horseshoe bat (Rhinolophus landeri) from Gorongosa and a sonogram of its echolocation.

The setup for photographing bats in flight will be familiar to anybody who has ever worked with high speed photography: I used an external, very fast shutter (6mS response time, 10-50 times faster than the shutter in a typical SLR) mounted on a Canon 7D with a 100mm macro lens, triggered by two intersecting laser beams, and with four Canon flash heads that provided the illumination. Cognisys is a company that sells turnkey solutions for high speed photography, and their excellent StopShot system is what created the basis of my setup. The tricky part was to create a stage where the bats’ flight path was relatively narrow, allowing me to illuminate it properly. Last year I photographed bats in a cave, which was relatively easy, but gave me little control over the lighting. I needed to restrict their movement better, and decided to bring a large diffusion box that I would then turn into a flight chamber for the bats.

The box was about 1 m (3 ft) long, giving even the largest Gorongosa species ample room to fly. On the sides of the box I cut out two small windows (covered with thin, clear Perspex) that allowed the laser beams to go through. The front of the box had to remain unobstructed to the lens, but something had to stop the bats from flying out; I ended up using a large piece of thin glass (and had to adjust the flashes so that they would not reflect off the glass). But somebody had to put the bats in there, and it was not going to be me (one word – rabies!)

Leaf-nosed bat (Hipposideros caffer) from Gorongosa and a sonogram of its echolocation.

Leaf-nosed bat (Hipposideros caffer) from Gorongosa and a sonogram of its echolocation.

Luckily, I got help from Jen Guyton, a Princeton graduate student and a bat specialist, who is working on her Ph.D. in Gorongosa. Since capturing bats to get samples of their DNA (or rather the DNA of their prey) was part of her nightly routine, Jen was able to bring live bats to my studio and control them while I took the photos. Once all the technical kinks were ironed out, the system worked like a charm – in a few minutes I would get multiple shots of each bat, and then the animal was removed from the chamber unharmed.

A studio setup for photographing bats in flight: (1) Cognisys high speed shutter, mounted on Canon 100mm lens; (2) a laser and a laser beam sensor (an identical but vertically reversed set is positioned on the opposite side of the box).

A studio setup for photographing bats in flight: (1) Cognisys high speed shutter, mounted on a Canon 100mm lens; (2) a laser and a laser beam sensor (an identical but vertically reversed set is positioned on the opposite side of the box).

But some species turned out to be more difficult than others – members of the family Molossidae (my favorite bats) are not able to lift off from horizontal surfaces and thus could not fly in the box. Next month I plan to photograph them in the wild by combining this system with a UV light – I hope that the bats will be attracted to insects coming to the light (which they often are) and sooner or later will hit the laser trigger. Watch this space to see if it worked.

One final note – don’t try any of this at home! Nobody but professionals, vaccinated against rabies, legally permitted, and fully trained to handle live bats should ever attempt catching these animals. If you are interested in photographing bats, get in touch with a mammalogist at a nearby university or a conservation group that works with these mammals, and they may be able to help you. They are an awesome group of animals, but don’t risk their or your own life. Having seen Gorongosa bats’ unbelievably sharp, lyssavirus-carrying teeth in action, I now think of them as flying vipers – cool, beautiful and fast and, potentially, very deadly.

A grey form of the Horseshoe bat (Rhinolophus landeri) from Gorongosa

A grey form of the Horseshoe bat (Rhinolophus landeri) from Gorongosa

 

Mozambique Diary: The House of Spiders

A guest post by Edward O. Wilson

The skeletal remains of the Hippo House, once a busy restaurant and observation point.  Orb weaver (Nephilengys cruentata) from the Hippo House.

The skeletal remains of the Hippo House, once a busy restaurant and observation point.

Each spider in the Hippo House was sheltered in a tubular retreat, a behavior typical of all species in the genus Nephilengys.

Each spider in the Hippo House was sheltered in a silken, tubular retreat, a behavior typical of species in the genus Nephilengys.

At the end of a long rutted road in the park sits a conspicuous artifact in the midst of wilderness. Built in 1970, the Hippo House was the vantage point, the antigo miradouro, from which well-heeled tourists, cool drinks in hand, watched wildlife herds as they grazed over the vast floodplain grassland below. Today the herds are back, but the house is a seldom-visited ruin. During the Mozambique civil war, almost all the buildings of Gorongosa National Park were torn down or blown away, leaving behind a few remnants scarred by bullets. The house had been reduced to a shell of its original self.

When I first visited the Hippo House, Mozambique was in the middle of the winter dry season. Other than along the watercourses, the vegetation of Gorongosa was brown and withdrawn. Insect life was still abundant, but harder to locate. I had been told that spiders, big ones, were abundant at the house, but I was quite unprepared for what I found. The interior of the ruined building was powder dry. Its floor, stanchions, and ceiling were windblown and coated with dust. No vegetation reached in from the outside, and except for a few small geckos resting on the pillars, there was no immediate sign of life of any kind. Instead, torn webs and long single threads of silk dangled from the ceiling like ghostly decorations in a haunted house. They swung gently back and forth in the occasional light breeze. No other movement or sound came from the seemingly empty space.

An unlucky katydid that flew into a web under the Hippo House is immediately killed and wrapped in silk by a female orb weaver.

An unlucky katydid that flew into a web under the Hippo House is immediately killed and wrapped in silk by a female orb weaver.

Where were the spiders I expected? Not one could be seen. But I knew they must be there someplace, alive, perhaps watching us. The idea of a hidden arachnid horde ready to rush out made me uneasy. Soon I saw something else: round objects plastered onto the ceiling. They were dusty and silent. My companions and I picked up a stick lying on the ground outside that was long enough to reach the ceiling, and tore two of the pouches apart. They proved to be silken egg pouches, undoubtedly made by spiders but now dry and empty; we were obviously not in the breeding season. The spiders themselves stayed hidden. Where were they? I grew more apprehensive.

We saw other, much larger, oblong pouches scattered over the rough eroded ceiling. At the tip of each was a circular entrance opening to a hollow interior. Using a flashlight and looking straight down the chamber, we could see what lay within. There at the rear of each pouch crouched a large spider, facing outward, its fangs, eyes, and the front of its tightly bunched legs visible. I wanted to see a specimen well enough to identify it, but hesitated. I was, to be frank, afraid of these crouched and waiting spiders. I suffer from mild arachnophobia. This spooky place was the setting of an arachnophobe’s nightmare.

The golden orb-weaver (Nephila senegalensis) is one of the largest spiders of Gorongosa. Its name comes from the beautifully golden coloration of its silk.

The golden orb-weaver (Nephila senegalensis) is one of the largest spiders of Gorongosa. Its name comes from the beautifully golden coloration of its silk.

We selected one of the pouches and poked at it in and out, but the spider stayed tight inside. One of my companions then took charge. He tore open the pouch and shook the inhabitant out into a transparent plastic bag. At last I could see what had lain within. The spider was heavy-bodied, the size of a thimble. When it suddenly spread its spiny legs, its width almost tripled.

I had solved the mystery of the spider house, at least in theory. The creatures in the silken bags were orb weavers, members of the spider family Nephilidae, called golden orb weavers, and, I later learned from an arachnologist, the species is Nephilengys cruentata. Some species of nephilids and the closely related araneids hide in retreats next to their webs; others remain in the centers of the webs. But how could there be so many spiders of this one species crowded together? Why are there no other creatures of any kind? The explanation I believed to be immediately clear. The floor of the lower level of the spider house is a layer of concrete. The interior is abnormally dry. Because the lower level cannot be invaded by any vegetation, few if any other forms of insect or arachnid life can live there. Yet flying insects undoubtedly fly through the wide-open space of the lower level, in through one side and out the other. A few might settle there to rest. The fate of most or all is the same: spider food.

Orb weaver (Nephilengys cruentata) from the Hippo House.

Orb weaver (Nephilengys cruentata) from the Hippo House.

My imagination was roused by this bizarre little world, but more so by my own reaction to it. When I took the captured spider back to Chitengo Camp, I found I was unable to make a specimen of it. That would mean fishing the monster out of the cellophane bag and working it into a bottle of preservative. So I simply opened the rear window of my room and dumped my captive live onto the ground below, where it would at least have a chance of making its way to a tree or building and spinning a new silken retreat.

I remember vividly the incident that made me an arachnophobe. I was eight years old. It was late summer, and I was exploring a vacant lot near our house. There were several full-grown female orb-weaving spiders in the high weeds, likely the common garden spider (Araneus diadematus), sitting in the center of their webs. I could not resist getting close enough to see all the details of one spider’s body. When I was about a foot away, it began to jerk back and forth in a menacing manner. I thought it was preparing to jump out and onto me. I ran. If that were not bad enough, I soon afterward saw a movie, the name of which I have long forgotten, in which a man is trapped in a cave. Blundering around, he becomes tangled in spiderwebs that are hung all around. Spiders, really big ones, climb down toward him, and . . .

Aversions and phobias of this kind, with the latter an extreme response causing panic and cold sweats, can be imprinted with as little as a single brief episode. They are rarely caused by a frightening experience with a knife, a gun, an automobile, or any other modern contrivance that can injure or kill. On the other hand, they easily and quickly follow a frightening experience with one of mankind’s ancient perils: snakes, spiders, wolves, heights, running water, and closed spaces. During millions of years of human prehistory, it has paid in a major Darwinian way to have quick, decisive response to the things that can kill you.

So I have forgiven myself for the wavelet of fear and revulsion I felt about the harmless denizens of the spider house. Let me make further amends by stressing that people are mostly safe amid what remains of living nature. We conquered the man-eaters long ago by destroying almost all of the big predators willing and able to hunt humans. They survive in our stories and in our legends of monsters. We imagine them silently emerging from caves and swamps, easing up from unexplored depths of the sea, or drifting down unseen from above. Walk into or swim in any wild habitat remaining on Earth, maintain the same level of caution you would on a city street, and you will be far safer than in most urban environments. Use common sense: don’t swim with crocodiles; don’t paddleboard among seals where great white sharks have been seen; and above all, never, ever run up to a mother grizzly bear with cubs to take a better look. Your greatest risk in the wild is from insect-borne disease—malaria, dengue, leishmaniasis, yellow fever—and these can be deadly if untreated. But they are transmitted chiefly among people. They can be easily avoided, and in any case pose less risk to you than the mélange of pathogens passing directly from person to person in human settlements.

The scary but harmless spiders in the Hippo House, and all the other animal species of wild environments like those of Gorongosa, are instinct-guided. They rigidly follow life-and-death routines formed during millions of years of evolution. Their lives are finely tuned and fragile in ways that are blessedly unthreatening to human beings.

Text Copyright © 2014 by Edward O. Wilson, Photographs Copyright © 2014 Piotr Naskrecki

Read more about the biological complexity and restoration of the fascinating ecosystem of Gorongosa National Park in “A Window on Eternity”, a new book by E.O. Wilson, with photos by P. Naskrecki (Simon & Schuster 2014).

Tarantulas, known in southern Africa as baboon spiders, may look frightening but are generally harmless. Their main line of defense is not their venom, but tiny urticating hairs that cover the entire body.

Tarantulas, known in southern Africa as baboon spiders, may look frightening but are generally harmless. Their main line of defense is not their venom, but tiny urticating hairs that cover the entire body.

Piotr Naskrecki and Edward O. Wilson in Gorongosa National Park, Mozambique.

Piotr Naskrecki and Edward O. Wilson in Gorongosa National Park, Mozambique.

 

Mozambique Diary: A single breath that changed the planet

The sound of an early ancestor of this lungfish (Protopterus annectens) taking it first gulp of air signified a pivotal moment in the history of life on Earth. The emergence of this behavior, along with the development of four limbs, set the stage for the conquest of terrestrial habitats by vertebrates, and the evolution of all tetrapods.

The sound of an early ancestor of this lungfish (Protopterus annectens) taking its first gulp of air signified a pivotal moment in the history of life on Earth. The emergence of this behavior, along with the development of four limbs, set the stage for the conquest of terrestrial habitats by vertebrates, and the evolution of all tetrapods.

About 400 million years ago, in the Devonian, in what was likely a shallow, freshwater pond in some tropical part of the world, a fish made a sound that started a dramatic chain of events, one that culminated in you and me being born. The sound was that of air being sucked in, as the fish lifted its mouth above the surface of the water, desperate to replenish falling oxygen levels in its bloodstream. Soon, gulping for fresh air became a necessity, as the gills failed to supply enough oxygen from the warm, muddy waters to sustain the animal’s activity. Its bladder, which up to that point helped maintain buoyancy for swimming, started to function as a gas exchange organ, an early version of lungs. At the same time, the fish’s pelvic and pectoral fins grew sturdier, and their connection to the rest of the skeleton more capable of lifting the body above the substrate. With these two steps the stage for the vertebrate conquest of land was set. We probably will never know when and where exactly this momentous transition took place, but we are pretty sure of what that fish looked like. And I am staring at it right now, as it looks back at me from the bottom of my beer cooler.

The Southern African lungfish (Protopterus annectens brieni)

The Southern African lungfish (Protopterus annectens)

Ever since I first set foot in Gorongosa National Park in Mozambique I have been obsessed with meeting my oldest living vertebrate cousin, the lungfish (Protopterus annectens). Despite its unassuming physique, reminiscent of a large eel, the lungfish holds a special place in the history of life on Earth. Biologists have always suspected that the lungfish gave us insight into the origin of terrestrial vertebrates, but only last year a massive molecular phylogenetic analysis (pdf) , based on 251 (!) genes, proved that the lungfish is a sister taxon to all tetrapods – amphibians, reptiles, birds, and you, and the rest of mammals. Previously that place was reserved for the coelacanth, a marine fish of equally ancient provenance, but now it appears that the coelacanth is an earlier offshoot of fishes that went its own, equally interesting, if less pivotal, way.

My first encounter with the lungfish took place a couple of months ago, when I ran across a fisherman who had caught a couple of these animals. Alas, by the time I met him they had been killed and gutted, leaving me heartbroken and even more obsessed. This time I made it abundantly clear to anybody who would listen that I wanted a live lungfish, and last week a fisherman from the village of Vinho finally delivered one into my hands.

In Gorongosa National Park lungfish are common, if rarely seen, inhabitants of seasonal water pans. During the dry season, when the pans evaporate, the lungfish burry themselves in the mud and estivate for several months. During this period their metabolic rates drop by about 60% and gas exchange is done entirely through their lungs.

In Gorongosa National Park lungfish are common, if rarely seen, inhabitants of seasonal water pans. During the dry season, when the pans evaporate, the lungfish burry themselves in the mud and estivate for several months. During this period their metabolic rates drop by about 60% and gas exchange is done entirely through their lungs.

It is difficult to describe the nearly religious reverence I felt when I saw my first live lungfish. Here was an animal that, I am pretty sure, looked like something I would see in the ponds of the early Paleozoic, long before first amphibians, even longer before dinosaurs. As I watched the lungfish slowly moving in my cooler, it suddenly lifted its head above the water and loudly inhaled a big gulp of air. I don’t think I will ever be able to forget the sound of it.

The lungfish does not have fins like other fishes. Rather, it has two pairs of whip-like appendages that act as weak, but very much functional legs. In 2011 an interesting experimental study (pdf) demonstrated that the pelvic fins are used by the lungfish in a fashion very similar to that of the land animals’ hind legs, for both walking and bounding. This in turn casts a new light on some early Devonian fossil tracks that were thought to have been left by primitive amphibians – in fact, they probably are those of semi-terrestrial lungfish ancestors. The development of articulated limbs with fingers (digited limbs) no longer seems to be the prerequisite to the conquest of land.

If you think that this looks like walking that’s because it is. Lungfish use their pelvic fins in a way very similar to that of a tetrapod’s legs – the distal part of the fin becomes a “foot” and the fins produce both walking and bounding motions.

If you think that this looks like walking that’s because it is. Lungfish use their pelvic fins in a way very similar to that of a tetrapod’s legs – the distal part of the fin becomes a “foot” and the fins produce both walking and bounding motions.

The more we study the lungfish the more fascinating it becomes. It is now clear that this animal holds the secret to the development of tetrapod ears, and they were the first to develop enameled teeth, the kind we, mammals now have. The lungfish is also superbly adapted to the harsh seasons of the southern African savanna, and can burry itself in the ground and survive for months out of water, hidden from the hot sun in a muddy cocoon (stories abound about African farmers digging out live, large fish from their dry fields.) Its dependence on atmospheric oxygen is so strong that the lungfish will drown if not allowed to breathe above the surface of the water. Its strongly reduced gills are virtually non-functional, but during the lungfish’s larval development are external and feathery, resembling those of the salamander larvae.

A portrait of the Southern African lungfish (Protopterus annectens brieni) from Gorongosa.

A portrait of the Southern African lungfish (Protopterus annectens) from Gorongosa.

In Gorongosa lungfish are common in seasonal pans and rivers of the park, feeding on a wide range of aquatic invertebrates, smaller fish, and frogs. As they are highly territorial, it is likely that almost every body of water on the plains has at least one of these remarkable animal. It is a shame that they are never seen by the visitors to the park – in my opinion the lungfish surpasses in its importance and a fantastical set of features any other vertebrate of Gorongosa, lions and elephants included, and I vow to make it my mission to spread the knowledge of its existence.

Last week, on March 27th, the E.O. Wilson Biodiversity Laboratory was officially opened, a culmination of my and many other people’s dream. More about the Laboratory soon, but I thought it fitting that the first vertebrate sample for our synoptic collection is a small snippet of the lungfish’s caudal fin, preserved for future DNA barcoding. The animal itself is being released back into its habitat, and I hope that this was not the last time that I looked into the eyes of my grand…grandfather’s twin brother.

Resembling an oversized salamander, the lungfish has four distinct limbs, a long tail, and only remnants of gills. The gills are virtually non-functional and the fish will drown if not allowed to breathe above the surface of the water.

Resembling an oversized salamander, the lungfish has four distinct limbs, a long tail, and only remnants of gills. The gills are virtually non-functional and the fish will drown if not allowed to breathe above the surface of the water.

BugShot 2014: Sapelo Island, GA

Polyrhachis

Intimate portraits: A queen ant (Polyrhachis armata)

My arrival in Johannesburg has brought a welcome respite from the unbearable winter of New England, and tomorrow I fly to Gorongosa National Park to begin preparations for the official opening of the E.O. Wilson Biodiversity Laboratory on March 27th. Stay tuned for updates and photos!

But there is something else that I am very excited about. Last year I was invited by Alex Wild to teach an insect photography workshop in Belize, the famous BugShot, and this year we are doing it again. This time the workshop will take place on Sapelo Island in Georgia, a place I have never been to but always wanted to visit. Insect life is bound to be spectacular – among other things I expect to find there Brunneria borealis, North America’s largest praying mantis and the world’s only fully parthenogenetic species of these insects. There are webspinners (Embioptera) there, two species of sylvan katydids (Pseudophyllinae), and over 100 species of other orthopterans. This is going to be good.

High-speed macrophotography: Periodical cicada (Magicicada septendecim)

High-speed macrophotography: Periodical cicada (Magicicada septendecim)

The workshop will take place on May 22-25 and there are still a few empty slots left. If you want to learn macrophotography, perfect your technique or learn a new one, or simply find out amazing facts about invertebrates, then you should join entomologists and photography experts Alex Wild, John Abbott, and myself on this fun adventure. Visit the BugShot website to find more details.

Wide-angle macro: Sylvan katydid (Celidophylla albiomacula)

Wide-angle macro: Sylvan katydid (Celidophylla albiomacula)

Time lapse macrophotography: A molting katydid (Enyaliopsis petersi)

Time lapse macrophotography: A molting katydid (Enyaliopsis petersi)

Ambient light macrophotography: Atlantic shield-back (Atlanticus testaceus)

Ambient light macrophotography: Atlantic shield-back (Atlanticus testaceus)

Tough as nails

Vernal pools are unique aquatic ecosystems, fleeting and unpredictable, but rich in animal life.

Vernal pools are unique aquatic ecosystems, fleeting and unpredictable, but rich in animal life.

Last night I finally managed to see the movie “Gravity”, which proves to me incontrovertibly that humans are not meant to stick their noses outside the protective layer of Earth’s atmosphere, despite having developed all kinds of high tech space gear (which, incidentally, seemed to have been designed primarily to kill Sandra Bullock’s character.) But this unexpectedly beautiful movie also made me think of a certain creature, whose amazing survival skills had lead NASA to use it to test the limits of life’s perseverance in outer space, long before somebody finally realized that people floating aimlessly in the cosmic void make for much better television.

To photograph fairy shrimp and other inhabitants of vernal pools directly in their habitat I used a complicated underwater setup with live video feed that allowed me to see what was in front of the lens. When I turned it on I was amazed how much life was there, it was almost as if I suddenly looked at a tiny coral reef.

To photograph fairy shrimp and other inhabitants of vernal pools directly in their habitat I used a complicated underwater setup with live video feed that allowed me to see what was in front of the lens. When I turned it on I was amazed how much life was there, it was almost as if I suddenly looked at a tiny coral reef.

As the first sunny days of March begin to melt away frozen remainders of winter in the northeaster United States, members of an ancient lineage of animals are getting ready to spring back to life. Throughout most of the year their habitat was as dry as a bone, but when the last patches of snow turned into water, leaf-packed depressions on the forest floor suddenly transformed into small, ephemeral ponds. Known as vernal pools, these fleeting bodies of water will be gone again by the time summer comes, but for now they create a unique aquatic ecosystem. Soon, the water is filled with thousands of tiny animals, at first not much larger than the point at the end of this sentence, but within a few weeks reaching the length of nearly a half of a pinky finger. They are the fairy shrimp (Eubranchipus vernalis), members of a group of crustaceans known as branchiopods, animals that were already present in the Cambrian seas half a billion years ago, before any plants even considered leaving water for terrestrial habitats.

Male fairy shrimp have massive, highly modified antennae, which they use to grasp and hold the female during mating.

Male fairy shrimp (Eubranchipus vernalis) have massive, highly modified antennae, which they use to grasp and hold the female during mating.

Looking at the delicate, soft body of a fairy shrimp it is hard to imagine how a lineage of organisms so seemingly fragile could have survived for so long. Take one out of the water, and it is dead within seconds. Let the oxygen level in the pond drop, and the entire population is wiped out. Given a chance, a single fish could probably do away with them all in a day, but luckily fish don’t do well in ponds that last for only a few months of a year. But fairy shrimps’ frailty is an illusion because where it counts they are as tough as nails.

In the northeastern United States several species of salamanders, such as this Spotted salamander (Ambystoma maculatum) from Westfield MA, share vernal pools with the fairy shrimp.

In the northeastern United States several species of salamanders, such as this Spotted salamander (Ambystoma maculatum) from Westfield MA, share vernal pools with the fairy shrimp.

If you live in a place as transient as a vernal pool, here now but gone in a few months, an environment of unpredictable duration and often uncertain arrival, you better have a solid survival strategy to build your life around. First, once the right environment appears, you must develop very quickly and reach reproductive maturity before the changing conditions kill you. Second, you need a method to keep your genetic line alive, even when the only habitat in which you can survive is gone. And third, plan for the unforeseeable cataclysms, such as sudden evaporation of the pool before you are ready to produce a new generation. Because, if you fail on any of these accounts, your species will not last past the first generation. Fairy shrimp, despite their unassuming physique, are master survivalists in the most hostile and unstable of habitats, and execute the three-step action plan flawlessly.

Male fairy shrimp (Eubanchipus vernalis).

Male fairy shrimp (Eubanchipus vernalis) from Estabrook Woods, MA.

As soon as the vernal pool forms, cysts containing fully formed shrimp embryos from the year before break open, and minute, swimming larvae emerge. They immediately start feeding on microscopic algae and bacteria already present in the water, and grow like crazy. During the first few days of their lives, baby fairy shrimp, known as nauplii, increase their length by a third and nearly double their weight every day. In about a month the animals are fully grown. One pair of the males’ antennae develops into giant, antler-like projections that help them catch and grasp their mating partners, while females grow big egg pouches on their abdomens. A few days later females start to lay at the bottom of the pool large clutches of cysts, eggs with embryos already developing inside, and die shortly after. Soon the water level in the pool begins to drop, and by June all traces of the once vibrant aquatic habitat are usually gone.

The body of a fairy shrimp is nearly translucent, which makes them invisible to a predator looking from above.

The body of a fairy shrimp is nearly translucent, which makes them invisible to a predator looking from above.

But inside the cysts hidden under a thin layer of soil the embryos are very much alive. They slowly continue their development, but can remain in the dormant state, out of the water, baking in the sun or being frozen in ice, for many years. Their outer shell is nearly waterproof, and quite sticky. This stickiness explains the sudden appearance of fairy shrimp in the most unexpected places, including old tires filled with water, after hitching a ride on the legs of birds and other animals. These cysts can live through being dipped in boiling water and liquid air (-194.35 °C, or -317.83°F), which is one of the reasons why these organisms are being used by NASA to test the survival of life outside of Earth’s atmosphere.
The following spring, if everything goes as planned, water of the melting snow awakens the dormant embryos, and within a few days they break the shell of their tiny survival capsules. But not all of them. Only a portion of the cysts responds to the first appearance of water, while others continue their slumber. If the pool dries prematurely, as it sometimes happens during a particularly warm spring, all early hatchlings die, and a second batch of larvae will emerge only if the pool fills up with water again. It has been shown that some cysts in a clutch will wait through eight cycles of wetting and drying before finally deciding to hatch. Fairy shrimp have evolved this ingenious strategy of hedging their reproductive bets in response to the erratic nature of their habitat, and it clearly serves them very well.

Fairy shrimp swim upside down, using 10 pairs of legs to propel themselves and collect bits of algae to feed on.

Fairy shrimp swim upside down, using 10 pairs of legs to propel themselves and collect bits of algae to feed on.

Mozambique Diary: Pardalota

Pardalota reimeri, probably the most colorful and one of the rarest katydids in the world. The individuals I observed in Quirimbas are the first record of this species in 103 years.

Pardalota reimeri, probably the most colorful and one of the rarest katydids in the world. The individuals I observed in Quirimbas are the first record of this species in 103 years.

Ever since I can remember I have been having a recurring nightmare: I am in some incredible location – usually somewhere in the tropics, there are amazing insects everywhere, often those that I have been dying to find, but I need to leave immediately and have none of my collecting gear – not a single vial, no net, no camera (not everybody can relate, I realize, but entomologists know what I am talking about). And last month I finally got to live through this bad dream.

A defensive display of Pardalota reimeri – these katydids feed on highly toxic plants and is likely that their bodies are loaded with poisonous alkaloids.

A defensive display of Pardalota reimeri – these katydids feed on highly toxic plants and is likely that their bodies are loaded with poisonous alkaloids.

Before coming to Gorongosa I flew to the northern town of Pemba where a newly opened campus of the University of Lurió trains Mozambican students in biology and engineering. It was supposed to be a strictly-business trip, meeting lecturers and students, and for this reason I did not bring with me any collecting or sound recording equipment, and only the most basic photo gear. But my friend Harith had a better idea and decided to take me on a short trip to Quirimbas National Park, famous chiefly for its spectacular marine life. Some of his students were working on insect and amphibian faunas of the park, and I said, “Why the hell not.” The seemingly easy trip turned briefly into hell after our Mitsubishi truck decided to part ways with its clutch right in the middle of nowhere. After a long while a friendly driver in a passing car went to fetch a tow truck for us, and eventually we made it to the park.

An unidentified, aposemtically-colored tiger moth found on the same plants as Pardalota.

An unidentified, aposemtically-colored tiger moth found on the same plants as Pardalota.

The first thing that I noticed was the wall of insect sound. The lush miombo forest reverberated with loud katydid calls, ones that I did not recognize. They were unusual for a couple of reasons. One, it was the middle of a hot, African day, and katydids tend not to like it, preferring to call under the cover of the night. And two, the calls were continuous, low frequency, and very complex. They were telling everybody with ears, “Here I am, come and get me.” And when you do that you better have a good trick up your sleeve to protect yourself, as katydid ladies are not the only ones listening: birds, lizards, monkeys, they all love big, juicy insects.

The katydids were calling from high in the trees and I was afraid that I would not be able to catch, or even see them. But then one flew down from the canopy and landed right in front of me. When I saw what it was, my heart skipped a beat – it was Pardalota reimeri, the Holy Grail for katydid aficionados (there are a few of us out there). This species had been known only from the original type series, described in 1911 and preserved in a museum in Berlin. What is special about this species is that even those old, dried husks retained vivid, crazy colors, unlike those of any other known katydid species. And colors as awesome as this indicate an equally awesome biology.

I caught the katydid and he immediately went into a defensive mode: he opened his bright purple, black and white wings, and exposed his neon-orange abdomen and cervical membrane; he lifted his hind legs that had yellow and black markings, remarkably similar to those of toxic chrysomelid beetles. This was either a daring bluff, or this thing was seriously poisonous. All around me other males continued to sing.

A video of a P. reimeri nymph – although the insect is not feeding it gives the perfect illusion of the front end of a fuzzy caterpillar chewing on a leaf.

What to do? Here I was, surrounded by a remarkable entomological discovery, but with no way to collect, preserve, or record it. I decided to exploit Harith’s students and we fanned out looking for the insects. Soon we discovered where they sang – they were only calling from, and feeding on, two species of trees, both known to produce potent chemical defenses, including some powerful psychoactive alkaloids. This almost certainly explained their aposematic coloration. We also found nymphs of this species, which turned out to be incredibly hairy. In fact, when I first saw one I thought I was looking at a fuzzy caterpillar feeding on a toxic plant – its movements were an uncanny imitation of the front end of a caterpillar chewing on a leaf, even though I was looking at at the katydid’s butt. It wasn’t shocking then when a minute later I noticed very similar looking caterpillars feeding on the same plant and, also on the same plant, tiger moths (well known to be toxic) wearing colors very similar to those of the katydids’. Having nothing else at my disposal I pointed my Canon 6D at the canopy and used its video recording feature to record the sound of the singing males. I collected as many individuals as I could, stuffing them into Ziplock bags, hoping to be able to get decent photos and proper sound recordings later on.

In the end I managed to collect enough material and data to write a short note about the biology of this species. But not being able to do a very good job at data and specimen collecting in the field was not a pleasant experience. I have already learned never to go anywhere without my headlamp, a GPS, and a camera, and now I am adding to this list an ultrasonic sound recorder and a large set of vials with 96% ethanol. On the second thought, maybe also an extra clutch for a Mitsubishi and a satellite phone. And some beer, for emergencies.
Two nights later I had a nightmare about Quirimbas.

A female P. reimeri cleaning her foot.

A female P. reimeri cleaning her foot.