TROPICAL SPIDERS AND THEIR KIN 3-30-10

Trinidad Chevron, Psalmopoeus cambridgei

More Psalmopoeus cambridgei

Even more Psalmopoeus cambridgei.

The common name, Chevron Spider, becomes obvious. This guy lives in the adjacent pipe.

Another juvenile in a tree.

Can you find the Psalmopoeus in its natural habitat on this strangler fig tree in Trinidad?

Psalmopoeus in hunting mode. Note the iridescence on the legs.

Same Psalmopoeus outside of its lair.

Goliath Bird-eating spider, Therophosa leblondi from the Amazon

Photo by David Bull

Texas Brown Tarantula, Aphonopelma (=Dugesiella) hentzi – threat display (l) and on its back (r) – note the fangs in each photo - southwest U.S.

If you’re lucky, we may let you hold one, like Alana Whitehead is here.

Red-rumped Tarantula, Brachypelma (=Euathlus) vagrans - Belize

We occasionally find a female outside her burrow with her eggs during the day – she is either thermoregulating or dehumidifying them.

When alarmed, the female usually quickly takes her egg case to her burrow.

After hatching, the spiderlings congregate on webbing at the burrow’s entrance for a day or so.

Red-rump egg case with shed skins of spiderlings.

Scary Sign at Cockscomb

Pink-toed Bird Spider, Avicularia avicularia: adult, web, & collection in Trinidad.

Golden Orb Weaver, Nephila clavipes: Female full of eggs and a pair on a web

Argyrodes, a small, metallic kleptoparasite on Nephila webs

Arachnoleptic fit (n.):

The frantic dance performed just after you've accidentally walked through a spider web; happens most frequently to the tallest person in the group (e.g., Dr. Bob).

The worst kind!

Ogre-faced Spider, Dinopis and its “castnet” - Trinidad

Belize 2005 on Gibnut trail

Belize 2005 Gibnut Trail

The web of an Australian funnel web spider, genus Atrax.

The ctenid spiders are the dominant “hunting” spiders of the tropics. One, the Brazilian Wandering Spider (Phoneutria), is very dangerous – and aggressive. Be sure to shake out your pants each morning!

A Nurseryweb Spider, Dolomedes, on her nest full of spiderlings

Fishing spider, Dolomedes sp., in Cockscomb.

Cyclosa – hiding in a string of junk. Can you see the spider?

Trinidad, November 2009

Huntsman Spider, Heteropoda venatoria, with egg case: Punta Gorda, Belize

Wolf Spider, Hogna (=Lycosa), with its egg sac attached to its spinnerets, and newly hatched spiderlings on its abdomen

Another Hogna with young.

Orb Weaver in Trinidad

An orb weaver in Belize.

Heinous Spider in Trinidad with its eggs

Heinous spider in Costa Rica with its egg sac.

Spitting Spiders, Scytodes, with eggs. Simla, Trinidad.

A sated tick on Bufo marinus! Tikal 2006

Opilionid with a mite parasite.

A male opilionid in Trinidad.

Opilionid eating a centipede – Trinidad.

Tailless Whipscorpion, Amblypygi, genus Tarantula - Belize.

Tailless Whipscorpion, Amblypygi, with young- Trinidad, November 2009.

Tailless Whipscorpion, Amblypygi, with young- Trinidad, November 2009.

Pseudoscorpions are always quite small and often hitch-hike on other invertebrates.

Pseudoscorpion (Pseudoscorpionida) on Amy Wilberding’s hand, Caracol 2005

Scorpions and their stinger.

Scorpion, Cockscomb 2005

This is the largest species of scorpion in Belize and is about 4 inches long when the tail is extended.

Scorpions are secretive and are usually hiding in rotting logs. They are nocturnal, and we will see them around where we stay and visit. Be sure to shake out pants and shoes each morning!

The proper way to pick up a scorpion is to pinch your fingers over the sides of the stinger – while the scorpion is running. It takes cool nerves and cojones grande. This is the common species we see in Belize.

Saul Sotolongo, the Man – 2002. Cockscomb.

Or, just gutsy, as is Jessica Forrester!

Recent studies have shown that at least some scorpions use two types of venom. Scorpions use a clear venom (called prevenom),

followed by a cloudy venom. Prevenom is less complex and is composed primarily of

potassium (16 times that of venom) that is deadly to invertebrates and produces a burning sting in mammals.

They later (maybe in the same dose) produce a cloudy venom that is composed of proteins (six times as much as in prevenom) and 100+ peptides. It does not sting as badly, but is five times as harmful to mammals.

Therefore, it appears that the less complex prevenom may be used to kill prey and warn mammals to back off. The venom convinces mammals that they made a mistake!

End of Creepy Crawly Stuff – for the moment!