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2 Dec, 11 tweets, 5 min read

Next up in #ScienteaficABC, AGELENIDAE! This family comprises 87 genera, totalling 1307 species & has an almost cosmopolitan distribution making it a commonly encountered family. The pic shows a few examples of members & some common features. (Images: Wikimedia Commons & my own)

Agelenid spiders vary quite a lot in appearance from genus to genus, but generally can be identified by eye arrangement (see my awful pic), web type/habitat & shape of cephalothorax... though, as always, there are some that do not fall in line with this which makes things fun 😂

Some members of this family are commonly confused with other types of spider. Take this as an example... Agelenopsis sp. (grass spider) vs. Rabidosa rabida (wolf spider), both from Virginia. The most reliable way to tell them apart is their eyes & spinnerets. (Pics: Wikimedia)

Wolf spiders have larger eyes and their spinnerets are not usually visible from above. Agelenopsis usually have elongated, visible spinnerets and smaller eyes in a different arrangement to those of a wolf. But you can easily see how they get confused! Anyway, moving on...

This is an adult male Eratigena sp. atrica group/giant house spider, a common sight in late summer and autumn in the UK, elsewhere in Europe & limited areas in the PNW (USA). Particularly notable in the UK as it is one of our largest species & very common in/around the house!

The name giant house spider usually refers to one of a few Eratigena species. To the untrained eye, other genera can look very much like them though. This is a Tegenaria silvestris. At a glance, they are similar, but the leg annulations (stripes) immediately set them apart.

Size varies a lot in this family with some species staying very small (less than 5mm body length) & some reaching leg spans of up to 10cm. Some live very close to humans, whereas some prefer remote habitats. This is Textrix denticulata, a smaller species. (image: Wikimedia)

Their webs are characteristically made up of a flat sheet of non-sticky silk, with a funnel shaped retreat, giving them (another) common name funnel-web spiders... NOT to be confused with Australian funnel web spiders! They are capable of impressive speed, esp. on their webs.

As a final note, this family is not medically significant. Though unlikely, if you were ever to get bitten, the venom they possess cannot harm you. Somehow, Eratigena agrestis, also called the 'hobo spider', earned a reputation for being dangerous. They aren't 😁

All images from Wikimedia Commons linked below. All other images taken by me.
commons.wikimedia.org/wiki/File:Laby…
commons.wikimedia.org/wiki/File:Text…
commons.wikimedia.org/wiki/File:Holo…
commons.wikimedia.org/wiki/File:Gras…
commons.m.wikimedia.org/wiki/File:Rabi…

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More from @tea_francis

🕷scienTEAfic🕷

@tea_francis

3 Dec

Bonus round! #ScienteaficABC. A small thread for this family AMMOXENIDAE! Why small? A few reasons. Firstly, it's a small family- 4 genera/18 species total, & secondly, they’re a specialised familiy so a broad summary should be pretty quick! (Images: Creative Commons, see end)

Ammoxenidae are commonly known as termite hunters. They are found in Africa & Australia, living on sand dunes, savannahs & bushland in both arid & tropical areas. They actively hunt for termites & when they're not hunting, they dig themselves into the sand. (Img: iNat cecileroux)

Once dug into the sand, they spin a silken retreat which is sticky on the outside so that sand grains stick to it & conceal it. They have adaptations to their chelicerae that enable them to dive face first into the sand and disappear from sight in seconds. (img: iNat peterwebb)

Read 9 tweets

🕷scienTEAfic🕷

@tea_francis

3 Dec

Another #ScienteaficABC. AMAUROBIIDAE! This family comprises 49 genera & ~275 species & can be found mostly around the world save for large swathes of the African, Asian & Australian continents, the Arctic & Antarctica. (images Wikimedia Commons & my own).

Amaurobiid spiders are generally quite rounded & velvety looking, not too vibrant or brightly coloured in most cases (though as you can see here, A. similis does try!), vary in size from 5-30+mm body length, & tend to inhabit cracks, crevices & other sheltered spots. (Pic: mine)

As with other spider families, eye arrangement is helpful (though by no means foolproof) in identifying Amaurobiidae. Here, enjoy another of my terrible diagrams! I shall accompany it with a photo to show you how they look on an actual A. fenestralis. (Image: Wikimedia Commons)

Read 10 tweets

🕷scienTEAfic🕷

@tea_francis

1 Dec

Kicking off #ScienteaficABC, taking it from the top with Actinopodidae! This is a family of mygalomorph spiders (an infraorder of heavy bodied spiders with downward facing chelicerae), comprising just 3 genera- Actinopus, Missulena & Plesiolena. (All images: Wikimedia Commons).

Actinopodidae can be found in Australia and Central & South America. They are considered medically significant, which means their venom is potentially dangerous. Overall, they are heavy set, impressive looking spiders, usually with a stocky legs, large chelicerae & fangs.

Perhaps most recognisable of this family are Missulena spp. The mouse spiders! Found mostly in Australia, 1 of the 18 species is found in Chile. This is a male M. occatoria native to S. Australia. Females do not exhibit the bright red that the males do & tend to be heavier set.

Read 9 tweets

🕷scienTEAfic🕷

@tea_francis

29 Nov

This is the entrance to my Theraphosa apophysis’ burrow. It’s gone to ground to moult. This species possesses the most irritating urticating setae (specialised itchy hairs used for defense against predators etc) of all known tarantulas.

The spider has burrowed down in such a way that I have a window into its moult chamber. The whole thing is lined with silk, but most amazing of all is the protective measure it has taken to deter any would be attackers from disturbing it while it’s in its most vulnerable state.

See all that fluffy debris all over the spider (who is upside down here)? Those are its urticating setae. Prior to beginning its moult, it kicked them all over its silken moult mat & when it flipped on to its back, the result was it being covered in these hairs.

Read 4 tweets

🕷scienTEAfic🕷

@tea_francis

29 Nov

Throwback to last May. I found these two Clubiona terrestris wandering about on a planter. I only had one vial to hand so I risked putting them both in it together just to get them inside. As soon as they met, one piled on the other & I thought that was it, game over...

Then I saw that what I actually had was a male & female & he had pounced on her to mate with her. What was most remarkable about this was the total lack of any kind of courtship behaviour or caution in approaching her. He just got straight down to it as soon as he got a chance.

She didn’t stop wandering around for a while... almost like she hadn’t even realised what was happening either. Eventually, they settled & remained coupled like this for over an hour.

Read 4 tweets

🕷scienTEAfic🕷

@tea_francis

28 Nov

On the subject of my Patreon, I want to create a space where people can follow along with the myriad spider related projects I'm working on, research, husbandry notes, photos etc, but I also want to make it into a forum of sorts where people can feel free to ask me about stuff.

I don't profess to be an expert in anything, but I have devoted a large chunk of my life to learning about the creatures I am so obviously utterly obsessed with. I want to share the things I have learned & continue to learn, and share the things I create too.

The tiers I have set up are super cheap- just £2 or £4.50 per month (you can read about what these get you here:- patreon.com/scienteafic?fa…). All of the proceeds are currently going towards an opportunity to join a research trip to Ecuador in 2021 which is a HUGE deal for me.

Read 6 tweets

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