Spiders are wonderful. There are so many types of spiders, we don’t know where to start. There are spiders that eat tadpoles, spiders that sit in holes waiting for trip wires to be sprung, spiders that shoot their hair out when spooked, spiders that hold their web in their hands and throw it on prey (like Predator), tiny spider-eating spiders that travel to other spider webs and pluck at the web pretending to be a late-night suitor, spiders that turn pink like flower petals and grab bees arriving to pollinate, and even a vegetarian spider.
We’re going to teach you a little bit about common spider families you might encounter, how to tell them apart, their likes and dislikes, and their familiar lifestyles, but before that — hear us out about CSIRO Publishing’s latest book: A Field Guide to Spiders of Australia.
Can you tell we love spiders? We love them so much CSIRO Publishing just published the most comprehensive book on Australian spiders to date, written by Robert Whyte and Greg Anderson. The book contains countless new entries for spiders never before described, photos of spiders never before photographed, and even newly discovered families (that’s big, if you don’t know)!
The book has over 1300 photos and covers all the families from the big two groups: ‘Mygalomorphs’ and the ‘Araneomorphs’, the old spiders and the new, and everything in between, including the bizarre alien butt and disco mirror ball spiders.
Just quickly, did you know you can roughly arrange spiders into those two groups: the mygalomorphs and the araneomorphs? Mygalomorphs are stocky, hairy, more ancient spiders that spend most of their time on the ground and use their large downward-pointing fangs to slam down on prey. These include the Sydney funnel-web spider and tarantulas. On the other hand (not literally), Araneomorphs are newer spiders that are much more common, which include ~90% of spider species. They create elaborate webs, come in many more shapes and sizes, and puncture their prey with a pincir-like nip, rather than a downward strike. Just imagine if you could only choose between a tooth pick or tweezers to pick up a stray grape on a plate, which would you use? Old spiders (mygalomorphs) stab with the ‘tooth pick’, while new spiders (araneomorphs) pinch with ‘tweezers’, which is much easier if you’re hanging upside down in a web.
Meet the families
Sure, we could promote the value of spiders by saying ‘spiders eat 400 – 800 tonnes of insects each year, sparing people all around the world from malaria, cockroaches and fly swats’, but is that nice? Evaluating a group of animals by what they do for us humans? Why not appreciate them for who they are? Take their eyes, for example.
Eyes are the window to the soul, and spiders are no different — except, instead of two gelatinous globes like ours, spiders have eyes aplenty, eyes that look forward, back and above all at the same time, some eyes 2,000 times as sensitive ours, so sensitive that they must be partly digested at dawn lest they burn up. Eyes, and their arrangement, are also a simple way to tell different spider families apart, so let’s use them for that. Here we go.
Taking a little look at the seven faces above, we’ll bet you can see three faces which are more similar to each other than the others. Would it be number one, two, and four on the top row? Wolf, jumping, and net-casting spiders have large, forward facing eyes because they need them to hunt. They’re proactive in catching their meals and can afford to spend resources on lovely big eyes, because they need them. The other faces above are just as ingenious, in their own myopic means, but we’ll get to them soon. (By the way, all seven of the families above are ‘araneomorph’ [newer] spiders.)
Wolf spider — Lycosidae
Wolf spiders have two large eyes at the front of their face, two eyes on the tops of their heads (looking out for birds and such), and four smaller eyes that form a little ‘moustache’. They have excellent vision — the third best out of any spider family, and are active hunters.
As their name suggests, they’re lone wolves, preferring to hunt in solitude. They go roaming for prey in leaf litter and in the undergrowth. If initial ambushes fail, they will chase down the prey over short distances. Wolf spiders are nocturnal. If you go for a walk in your backyard or in a park at night and flash a light over the grass, you may catch tiny glinting blue and green sequins that are the reflective eyes of wolf spiders out for a late-night snack.
Wolf spiders are known for their maternal qualities, too. They may not use silk to weave webs, but they do use it to create a sac for their eggs, which they carry around. Once hatched, the babies — sometimes hundreds — will climb onto their mothers back and live and grow there for months! And people are always taking photos of the koalas.
Jumping spider — Salticidae
Every group of animals has its poster boy. Slugs have their gaudy nudibranchs; fish, the clownfish; birds, the peacock; humans, Mick Jagger; but for the spider world, jumping spiders would have to be it. Jumping spiders have it all: charismatic eyes, often brilliant colours, and quirky mating routines that would flatter any self-respecting audience.
Jumping spiders have four well-developed eyes at the front of their face and the best vision of all spider families. They use their strong vision for identifying prey from a distance, and evaluating potential partners. Why hello there, this masked peacock spider above (Maratus personatus), looking a little like The Spirit, was voted the cutest spider.
Jumping spiders are also the most diverse family of spiders, with over 5,800 species in the group. And, as their name suggests, they are prolific jumpers. Since they are daytime hunters, it’s not uncommon to see them hopping around your backyard or even home, appearing simultaneously robotic and curiously sentient on the lookout for new destinations.
Though jumping spiders are meta-carnivores, in that they often prey on other carnivores like spiders, they contain the only known species that’s largely herbivorous, Bagheera kiplingi (yes, like the Jungle Book), which drinks nectar.
Of course, a discussion of jumping spiders wouldn’t be complete without a mention of peacock spiders, those extravagant eight-legged Rio Carnival dancers we all love to meme about. Watch them dance, here.
Huntsman — Sparassidae
We knew you were going to freak out in the huntsman section, so we got this picture of the green huntsman (Micrommata virescens) to calm you down. Huntsman are also known as giant crab spiders, which sounds more pleasant right? …maybe.
Huntsman have a rather simple eye arrangement: two rows of four eyes, like two-thirds of a carton of eggs.
There are almost 1,200 species of huntsman that live all around the world, with a preference for areas closer to the equator and tropics. Like humans, huntsman don’t build webs. They actively go hunting for it. They eat insects likes moths and cockroaches, but they can also eat larger prey like smaller lizards.
Huntsman are a dangerous spider, not because of their venom, but their appearance, which causes people to leap and convulse regardless of the activity being performed and often with disastrous consequences, like in February this year in the Blue Mountains when a huntsman fell onto a driver behind the wheel on a highway, causing a four-car pile-up.
In terms of locomotion, huntsman are very much the Splinter Cell of the spider world. They like to remain hidden, waiting in crevices for prey to approach, but chasing it down as necessary. They can lay their bodies flat and twist their limbs to move in extremely squishy places like their favourite habitat: under tree bark. It was recently shown that huntsman males attract mates by (sensually) vibrating their abdomens against a substrate to attract the attention of nearby female undercarriages.
Some huntsman get around by turning their limbs rigid and cart-wheeling down sand dunes. We did not make that up.
Net-casting spider — Deinopidae
We’ve been avoiding the Latin names so far, but the net-casting spider’s name, Deinopidae, bears explanation. You might recognise the ‘deino’ part from ‘dinosaur’, which means ‘terrible’ or ‘awesome’, and the ‘op’ refers to the eyes. That makes Deinopidae the spider with terror-inducing eyes, which explains the net-casting spider’s other common name: the ogre-faced spider.
Net-casters are inventive hunters, rather than spending time weaving an elaborate web that stops flying insects, net-casters hold a small net of web between their arms which they throw on the insect. It’s like spear fishing, where your dexterity and phantasmic stalking is what brings home the bread, or fish, or insect. This might be one reason you haven’t seen net-casting spiders, though they’re quite common. They hang upside down, suspended either by their long back legs or a thread of silk adhered to the leaves of Lomandra and shrubs, making themselves appear like a discarded twig. They hang, focussed over a patch of ground awaiting prey to walk past below.
Net-casters are nocturnal hunters, too. And in order to make the most of the faint night time light, net-casters grow a membrane of super light-sensitive cells in their eyes (2,000 times more sensitive than ours) to spot their prey. In order to calibrate their snaring, sometimes — while hanging upside-down — they will drop a contrasting white spot of faeces on the ground. This spot is their bullseye, and prey moving over and blocking this spot will trigger the net-caster to cast its web onto the prey. If no prey shows up on a nightly hunt, the net-caster will simply hang up their unused web on a twiggy coat rack. Keep an eye out for these bizarre and fantastic spiders next time you go for a walk.
Orb-weaving spider — Araneidae
If you’ve ever walked through a spider web and done that panicked sprint dance to swipe away the silky manifestation of death, then you can probably blame orb-weaving spiders, Araneidae.
Orb-weaving spiders have eight rather simple, homogeneous eyes. They craft amazing webs and include groups like St Andrew’s cross that create webs with a silky, white cross in the centre (called a stabilimentum) that reflects UV and is thought to attract prey and warn birds not to fly through them because no one wins there. Nephila, also known as golden orb-weavers are another frequently encountered group — those enormous spiders often depicted with hapless birds and other back-boned animals caught in their webs. Recent research has shown Nephila to strategically set up webs near streetlights, taking advantage of the moth to the flame effect. Another common orb-weaver group are garden orb weavers, those furry nocturnal spiders that emerge at dusk to begin weaving and wefting their webs across expanses between trees. Catching them in the process makes for pleasant evening viewing.
Many orb-weaving species exhibit ‘sexual dimorphism’, whereby males and females look conspicuously different, often with smaller males. Nephila — the golden orb-weaver — is one such group, in which the spider you’re probably familiar with is mostly female. Males are often tiny and look almost like offspring. Since many orb-weavers engage in sexual cannibalism, it may be a tactic on the males’ part to be small enough sneak up to his lover and land consummation rather than consumption.
Crab spider — Thomisidae
Crab spiders are sit-and-wait predators with an intimate relationship with flowers. These spiders are also common, though you’ve got to have a sharp eye to spot one. As crocodiles use watering holes as camouflage to take advantage of thirsty animals, crab spiders use flowers petals to grab nectar-thirsty pollinators like flies and bees.
Depending on the variety of crab spiders, they use either camouflage to blend in with the flower or do the complete opposite and become a ‘neon sign’ of sorts, contrasting drastically with the petal to excite and confuse flying insects into landing. Pollinators, crab spiders, and flowers form an interesting relationship triangle: the prey insects land on the flower to drink at the nectary, and in so doing, pollinate the flower. And since the flower relies on the insect to pollinate and fertilise itself for sexual reproduction, crab spiders therefore are a type of eight-legged condom.
Crab spiders are so named for their powerful, enlarged forearms which they use for grabbing and holding large prey items. They have smaller eyes, which point in various directions. Next time you’re walking the dog and you stop to smell the roses, have a little look for a crab spider, too.
A Field Guide to Spiders of Australia
That’s it for our guide to just six families of commonly encountered spider. You’re now more than equipped to start getting curious about the spider life around you, and discovering new groups not mentioned here. You might be wondering, how many families are featured in A Field Guide to Spiders of Australia? Good question — it’s 86.
Pick up a copy now and let us know how you like it.
Originally published on blog.csiro.au. Read the original article, here.