Cris - Week 4

Fluorescein dye in the inner basin

This week I went out to all six sites and did a measurement of the current. To do so I used fluorescein dye, which in its concentrated form is a red/orange color that changes to neon green once mixed with water. It allowed me to compare the water flow patterns in both basins by tracking the time it took the dye to cover a distance of 2 meters. These data will provide additional information as to why specific fouling organisms settle more in certain areas than others.

Botrylloides violaceus in fluorescein

treated water

I have also used fluorescein to identify how the water enters and exits tunicates, such as Botrylloides violaceus to the right. The two streams of dye going toward the top left of the photograph are coming from the tunicate's excurrent siphon. The pharyngeal basket is facing down in the frame with the incurrent siphon at the bottom. The tunicate draws water in with cilia located on its pharynx and filter feeds using the mucous produced by a ciliated groove called the endostyle.

Thamnophis sirtalis, common garter snake

Polychaete worm

The segmented worm on the right belongs to the class Polychaeta in the phylum Annelida, each segment bearing its own pair of parapodia. I noticed it while looking through the microscope and studying my plates. Its sudden appearance in the lens startled me as I did not notice it when I first grabbed the plate. To the left is a garter snake (in the genus Thamnophis) that resides in and around the stream here at OIMB. Along with this garter snake live frogs and rough skinned newts. Rough skinned newts produce tetrodotoxin, lethal to humans and other animals except the common garter snake. Lucky for the snake the stream is plentiful with newts. That's all for this week, cheers!