Isopoda Photo stories Reportage: Weird Nature The spider and the frog
The spider and the frog

By Francesco Tomasinelli and Emanuele Biggi

Updated 18/03/2008

Frogs have difficult lives in South American rainforests. Many of them are preyed by Snakes and by Artropods, especially by spiders which are big and particularly active at night. But there is a frog that developed a peculiar relationship with some spiders. This is the Microhylid Chiasmocleis ventrimaculata, who lives, often in good numbers, near spider burrows of some tarantulas species. The spider, a still undescribed Theraphosidae of the genus Pamphobeteus, tolerates the frog and never attacks it. Other amphibians passing outside his burrow are immediately captured, even by the young specimens which, in this species, remain with the mother for many month with no sign of cannibalism. This curious relationship is one of the few cases of mutualism between amphibian and spiders (the other involves Xenesthis immanis instead of Pamphobeteus sp.) for the first time photographed with such detail.
The advantages for the Chiasmocleis are obvious. She won't be attacked by other spiders and by small snakes: intrusions are not tolerated in the tarantula territory. And it’s possible the Arachnid is somehow helped by the frog who preys upon small parasites (mainly Diptera) and possible ants that could harm the spider or its eggs.

On Amphibians see also Saving frogs into the Amazon
On Arachnids see also Surprising spiders

Many thanks to Rudy Von May, Alessandro Catenazzi, Mo Donnelly, Nigel and Renata Pitman, Rick West and all the crew of the CICRA Los Amigos biological station in the Peruvian Amazon.



About this site

Welcome to, website of Italian biologist and science photographer Francesco Tomasinelli. My favourite photographic subjects are unusual animals, travels and scientists at work, but I shoot many other topics, like sports, events and corporate pictures. I work as scientific consultant too, mainly on nature conservation and as museum exhibit designer.


5-3-2016 New scientific exhibition Predatori del microcosmo at Firenze, Museo di Storia Naturale La Specola, until 31-5-2016

30-8-2015 New scientific exhibition Predatori del microcosmo at Treviso, Oasi Cervare, until 31-11-2015

10-11-2014 New scientific exhibition Predatori del microcosmo at Pisa, Museo di Storia Naturale della Certosa di Calci, until 21-6-2015

10-11-2014 New scientific exhibition Predatori del microcosmo for Università dell'Insubria, Varese, until 15-3-2015

24-11-2014 New book about urban animals - Vado a vivere in città. See many of the pictures in this photo story

7-12-2013 New scientific exhibition Zanne, corazze e veleni for Museo di Scienze Naturali di Genova, until 30-8-2014

10-11-2013 New photo galleries on Trento Science Museum MUSE and on Namib Desert.

15-5-2013 New photo gallery on Botswana wilderness safari.

8-3-2013 New scientific exhibition Copioni e copiati, for Museo Civico di Rovereto, until 31-3-2013  

21-10-2012 New photo gallery on Carnivorous plants. New gallery section on people at work.

18-07-2012 New photo gallery on Rio Negro exploration, Brasil. Updated information on Taxon exhibition in Montecarlo.

10-06-2012 New photo gallery on Genoa monumental cemetery Staglieno. Updated photogallery about animals in cities.


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