06/05/2022
John A. Kochalka dice: - In December 1981 in Parque Nacional Defensores del Chaco, Paraguay, I collected a species of tarantula (Eupalaestrus sp.) that lives in holes in the ground, frequently along roadsides, very common in the Chaco Paraguayo Central and elsewhere, and I discovered that when the hole fills up with rain water the spider stays in the hole with the water. For the next 40 years I was wondering if the spider can breathe underwater, and if so, how does it do this? (I always knew, but that's another story).
A couple weeks ago in San Lorenzo, on the University Campus I found another species of tarantula, Acanthoscurria sp., also living in a hole that had temporary rainwater in the bottom, and I remembered the spider from Dec. 1981 in Madrejón.
I´m still working on the photography, during last week, this and next week, and the attached photos are of a third species photographed on 5 May 2022, Grammostola pulchripes from Paraguarí, a species that is much more abundant in the Chaco Paraguayo Central, and also in almost the entire Chaco Region, but does not usually live in holes in the ground, - usually it lives in holes in trees, standing, fallen or rotten.
The photos I took yesterday show the Grammostola spider before and during submersion in water. Underwater the spider has a silvery air bubble called the "gaseous plastron" all over its body surface, which supposedly functions as a gill so the spider can breathe underwater, theoretically. Any observant arachnologist will notice that this air bubble also covers the spider's book lungs, which would be in accordance with the theory. I notice one more thing - it appears that the only part of the spider's body not covered by the bubble is the mouth. Theoretically the bubble is caused by water-repellent hairs, and even more theoretically, the hairs of the spider's mouth are NOT water repellent. This is very important, because if they were, the spider would not be able to drink water, and probably wouldn't even be able to eat, since all spiders consume only liquefied food. So there you have it, - Science progresses even faster than I do. Juan Bicho. John A. Kochalka, del Museo Nacional de Historia Natural del Paraguay, and ¿Cuántas especies hay en Paraguay? - IBNP-Museo pregunta.
