What creates these small, sand, chimneys on the flow-facing surface of boulders? These were found in Rio Bella Vista, a fast-moving, cold, cascading stream in Las Alturas.
Chimney building aquatic insect
Tag Archives: Costa Rica
Sherman traps for crabs
Some authors have evidently used Sherman traps, usually used for small mammals such as rodents, to catch semi-terrestrial crabs. Given that we don’t really know the terrestrial activity of the stream crabs in Las Cruces, we decided to set a few baited traps up, without luck. The crabs are small, so may not be large enough to trigger the trap, but all the bait was present after the test.
Tree fern
Leafcutter ant reproductive caste
The leaf-cutter, reproductive female caste (new queens – Atta cephalotes) emerge in mass and begin digging new homes!
Moss, tiny snails, and planarians
Revisiting Río Bella Vista
Initial dissection of crabs
The first project ideas Gabby and Juliet found interesting involved dissecting the pseudothelphusid crabs found in the streams in Las Cruces. While Gabby’s project has since changed dramatically from diet composition of the crabs to testing sex and heterochelae effects on agonistic behavior, Juliet is exploring trematode (Paragonomus spp.) parasite prevalence in the hepatopancreas (the yellowish tissue) in the crabs.
Forest of Sendero Echandi
Tropical, pre-montane wet forest with tree ferns, strangler figs, cerdro (Cedrella spp.), and some avocado relatives.
Parasitoid pupae from a caterpillar
Parasitoid larvae, probably from a wasp, have emerged from the black wounds of this caterpillar, perhaps a hesperidae butterfly, and pupated.
Check out the trachea (the branching gas exchange organs observed through the skin of the caterpillar) and the punctures from the larval exits!
A pool in Río Java
