I discovered this large, terrestrial flatworm on top of the Guaycan overlook at Palo Verde. I wonder if it’s one of those cool predatory Geoplanids!?
Tag Archives: Invertebrates
Centipede and Eggs
I found her wrapped around her eggs and eating another centipede, presumably the male.
Millipede
Ostracoda
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This ostracod (seed shrimp) was stuck swimming in a pool formed atop a water lily. In general, they appear quite abundant, and this particular species/group are relatively large. That said, in the photograph to the left, there is a plant called Wolfiella next to the ostracod that is one of the smallest ‘macrophytes’ out here. In the other two photos you can see the legs or antenna the animal uses to propel itself.
I’ve collected many and may be able to say more about them in the future. |
Leech
I encounter leeches commonly in the wetland, particularly associated with decomposing macrophytes. I’ve never seen one attached to me, sucking blood, so I think they aren’t out for blood. Bernald has requested I catch a few, although this one got away after the second photograph…
Cruisin’ ostracod
| I’ve collected a bunch of these gigantic ostracods which cruise around, perhaps preying on grazing cladocerans. |  |
Tons of spiders
| A nest of recently hatched spiderlings disperesed from a small, stream-side plant in Rio Camarone, Sirena. |  |
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Man-O-War
This is what likely stings us while in the ocean in front of Campanario, according to Helena Molina. In that part of the Pacific coast of Costa Rica, they don’t get much larger than this (about the size of a silver dollar), so they aren’t very dangerous. They still hurt…
Limpkin feeding sites
Last updated:
23 May 2009
Figures 1 and 2 show a potential limpkin feeding site. I discovered 3 sites, one of which I had observed a limpkin fly away from. Before flying off, the limpkin was within 10 m of me, so I’m fairly confident that it had been standing at that location, but I was unable to observe a limpkin actually feeding at one of these locations. The shells are from a very thin-shelled aquatic snail that appear to be extremely abundant in a variety of vegetation types. I have encountered the snail in Pistia (Figure 3), an unknown emergent plant (see Massive herbivory; Figure 4), and Eichhornia.
The snail has no operculum and, when handled, doesn’t usually escape into its shell. I’m unsure whether or not the snail is a scraper, consuming epiphytic biofilm, or consumes macrophytes proper. If they snails are scrapers and are limpkin prey, there may be an interesting interaction occurring; Apple snails tend to consume macrophytic tissue and scraping snails have been shown to increase macrophyte growth. It may be far fetched, but could apple snail predation effectively farm these snails?
Reduced apple snail density = greater macrophyte biomass = more surface area for biofilm formation = great thinned-shelled snail densities
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Other than apple snails at snail kite perches, there was one other species of snail present. Figure 5 shows a snail shell found along with apple snail shells at a snail kite perch. Although this snail may also have been prey, several individuals were found lodged within apple snail shells, so these snails may have died while consuming left over apple snail tissue or attempting to escape drought. The shell is much thicker than the shells found at the limpkin sites discussed in this post, and is not likely the same species.
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Dry Season Crabs
At Campanario, in the Osa Peninsula, there were land crabs everywhere during the night. They were beautifully colored and I caught a couple of them consuming fallen, decomposing leaves near a stream, which is of course interesting to me. They were much more abundant this March than in January.