Proboscis into host Bohadschia ocellata. Second image also showing symbiotic copepod on holothurian.
Found on irregular urchin, probably a species of Metalia.
Found on Echinaster luzonicus starfish.
This snail was observed on August 13,2019. The time the picture was taken was 09:43 central standard time. It was located in the Mistico Arenal Hanging Bridges Park in Costa Rica. Inside the park, it was very humid and rainy. It was near the base of Arenal volcano. This snail belongs to the phylum Mollusca. The snail was about 1 inch long. The shell was bright yellow and had grooves creating a spiral. This snail is a protostome. https://en.wikipedia.org/wiki/Allopeas
Snorkeling in shallow water (< 20ft/6m).
Marvelous tiny thing with a shrimp-like face. Last photo shows more of my hand for some scale: the top right corner of my left hand, just under my little finger. Tiny shell!