Tuesday, October 11, 2011

Cost Rica - Arañas

The spider fauna on the Osa Peninsula is rich and diverse. All the species here are new to us of course, but some of the families are too. The most obvious spiders here are from the Ctenidae; the wandering spiders. There are numerous species here and are easily spotted at night using a head torch. There are several species of tarantulas (Theraphosidae) here too, and we recently found a road side cutting with large numbers of hand-sized specimens (Brachypelma angustum) sitting outside their burrows.

Every night we see more and more spiders. Here is a small selection of the spiders we have encountered so far - some of the smaller species are truly spectacular.

A 'leopard' wandering spider, Ctenidae 

Red-thighed Wandering Spider, Cupiennius coccineus

Costa Rican tarantula, Sericopelma sp.

Male tarantula, 'Crypsidromus sp.'

Costa Rican Orange-mouth Tarantula, Psalmopoeus reduncus (female)

Male Costa Rican Orange-mouth Tarantula, Psalmopoeus reduncus (male)

Costa Rican Orange-mouth Tarantula, Psalmopoeus reduncus

Silverback Cross Spider, Argiope savignyi

A huntsman spider, formerly Olios now being reclassified.

Flame-bellied Orb-weaver (Eriophora sp.), wrapping prey

Flame-bellied Orb-weaver (Eriophora sp.) This species has a huge ladder-like orb-web which often connects with the ground. During the day they hide above the web in a curled leaf.

A bizarre Lynx spider, Oxyopidae. This species lies flat underneath broad leaves.

Not sure about this one - could be Oxyopidae or a Mimetid

Pedipalps to be proud of. A male pirate spider, Mimetidae.

The female of the same species. We could not identify this Mimetid beyond family level. The eye-spots on the abdomen make it look a little like a South Park character.

Another individual of the same species.

A Red house spider (Nesticodes rufipes). This species seems at home both in houses and within the rainforest.

A small but robust Oxyopid feeding on a wasp.  The spider is hanging from a strand of silk.

Selenops sp. This lighting fast spider is at home on rocks and on tree trunks.

The spiny Micrathena sexspinosa. A common orb-weaver on the Osa Peninsula. 

A large Scytodes sp.; a spitting spider. These six-eyed hunters eject venomous silk from their spinnerets. We were able to capture action in the studio.

A jumping spider (Salticidae). 

A triangular orb-weaver, unknown species.


  1. What stunning photos. I was arachnophobic for many years until I stopped to look at the wonderful beauty and build of our spider friends. Now I just adore them!

  2. Love them all. The Flame-bellied Orb-weaver is a stunner, and I was surprised to see it is Eriophora, just like our local garden orb weavers.

    Strange that you have two Lyn(ne)'s commenting, both who used to be arachnophobes and are now converts. Your influence, Alan? Certainly was in my case!

    Stunning photos, as always.

  3. And thanks, Lynne, for pointing me here. Now I am eaten up with jealousy :-)

  4. Oooh, spiders are really creepy. But these web spinners truly play an important role in preserving the balance in the wilderness.

    Darius Adlam

  5. The spider in one of your picture which you are unsure whether it is an Oxyopidae or a Mimetid, it is actually a Lynx Spider (Oxyopidae). You can tell that it is a Lynx spider from it's eye arrangement and spiky legs.
    Goodluck in finding more interesting minibeasts.