Vegetarian spider
by David Catchpoole
Certain Acacia trees are well known for having resident ants. Ants eat
the distinctive leaflet tips known as Beltian bodies—nubbins of protein and
fat—and they drink the nectar that oozes from special nectaries on the leaf
petioles (i.e. “little stalk” between stem and leaf). Often cited as
a textbook example of a “mutually beneficial partnership” (or symbiosis),
the resident ants fiercely defend their home trees against caterpillars and other
invaders that might chew on the tree.
However, in Mexico, it seems the ants (Pseudomyrmex) are having to share
their arboreal abode with a rival herbivore—namely, a spider.1 Bagheera kiplingi
gets its name from a panther in a Rudyard Kipling story. Panthers are of course
adept at leaping, and so is this spider—in fact a report in Science News
says Bagheera kiplingi “belongs among the big-eyed, athletic predators
in the family of jumping spiders”.2 Researchers have recently been surprised,
however, to discover that a population of these spiders in Central America is “predominantly
vegetarian”, dodging the ant guard patrols to forage on the fresh leaf tips,
and to a lesser extent on petiolar nectar.1
In videos of 140 spider meals, the researchers observed the spiders feeding on the
Acacia leaf Beltian bodies or nectar 136 times. On four occasions, spiders
opportunistically snatched away ant larvae being carried by a passing ant nursemaid,
and ate the larvae.
Despite the fact that “the tree is full of biting, vicious ant guards”,
given that up to several hundred spiders are resident on some individual Acacia
trees, the arachnids are obviously very effective at surviving despite the ants.
As Science News quipped, “These arachnid herbivores are no wimps.”2 Yet they are indeed mostly
vegetarian, based not only on the video observations but also on associated analysis
of spider tissue for particular isotopes of nitrogen and carbon3—the results
being typical of plant-eaters, not carnivores.
For some time now scientists have known that certain spider species occasionally
taste vegetable matter. Male crab spiders have been observed to sip nectar from
flowers, and some baby spiders eat pollen grains that have stuck to a web.2,4 But on hearing of this latest discovery of a “vegetarian spider”,
one scientist’s reaction was typical: “I was absolutely
floored.”2
This is not the first time that creatures thought of today as needing to eat other
creatures to survive turn out to have a diet derived largely, or even exclusively,
from plants instead.5–10
Such examples might be a surprise to people used to thinking our world is a product
of “dog-eat-dog”, “nature-red-in-tooth-and-claw” processes
over millions of years. But to Bible-believers, such instances of “unexpected”
herbivory are readily understandable as legacies of a “very good” creation
in which vegetarianism was a world-wide phenomenon,11 only around 6,000 years ago.
Readers’ commentsColin M., Australia, 8 November 2010
Search the Internet and you’ll be told that ALL cats are obligate carnivores. Our cats haven’t been told as they often eat brocoli, peas, corn and LOVE Rock Melon!
John J., United Kingdom, 9 November 2010
I never thought of spiders as being veggies. I have four dogs (Border Terriers) who are all happy vegetarians. They will eat meat if presented to them, but seem happier with a mix of vegetables (potatoes, cabbage, swede or whatever) and dog biscuits..
Peter K., Australia, 8 November 2010
My 2 cats have always (since kittens) enjoyed eating bread with gusto. They will typically tear through the plastic wrap to get to it! |
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References and notes
- Meehan, C.J., Olson, E.J. and Curry, R.L., Exploitation of
the Pseudomyrmex–Acacia mutualism by a predominantly vegetarian jumping
spider (Bagheera kiplingi), 12th International Behavioral Ecology
Congress, PS 62–107, Ithaca, New York, USA, 9–15 August 2008.
Return to text.
- Milius, S., Vegetarian spider: Small jumping species
steals lunch from ants, Science News 174(5), <www.sciencenews.org/view/generic/id/35121/title/Vegetarian_spider>,
30 August 2008. Return to text.
- I.e., 15N and 13C.
Return to text.
- White, T., Pollen-eating spiders, Nature Australia
26(7):5, 1999–2000. (We reported on
this in: Pollen-eating spiders, Creation 22(3):5,
2000; <creation.com/spiders_pollen>.) Return to text.
- Catchpoole, D., The lion that wouldn’t eat meat,
Creation 22(2):22–23, 2000; <creation.com/lion>.
(Refs 4b–10 can also be accessed via creation.com/carnivory.)
Return to text.
- Catchpoole, D., Catching a kinkajou, Creation
26(3):42–43, 2004; <creation.com/kinkajou>.
Return to text.
- Vegan dog, Creation 25(2):7, 2003.
Return to text.
- Catchpoole, D., The “bird of prey” that’s
not, Creation 23(1):24–25, 2000; <creation.com/vulture>.
Return to text.
- Match the bat’s teeth, Creation 21(1):30,
1998; <creation.com/bats#batteeth>. Return to text.
- Catchpoole, D., Lea, the spaghetti lioness, Creation
29(4):44–45, 2007; <creation.com/spag>.
Return to text.
- Genesis 1:29–31; see also Gurney, R.,
The carnivorous nature and suffering of animals, Journal of Creation
18(3):70–75, 2004; <creation.com/carniv>. Return
to text.
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