Eagle Project and Flatworms

Today's blog covers a couple of seemingly different topics but such is life here at HIMB. First off, we're always grateful to those willing to help us improve our island and its facilities!

Over the weekend, Eric Compton and his Scout Troop dedicated their time to installing gutters outside the Gates Wet Lab area.  Using donated materials from Hardware Hawaii and Home Depot, they constructed this mechanism for redirecting water from the lab, which frequently endures heavy rains and flooding.

                           

Photos taken by Leon Weaver

We need all the help we can get when it comes to preventing excess water from invading our research facilities!  Plus, this facility houses a state of the art research area where ocean acidification simulations can be set up and run to help understand changes on coral reefs. By cleaning up the outside, visitors are more likely to stop by and appreciate the cutting edge science inside. Check out Dr. Ruth Gates Lab facilities.

A few nights ago, Leon came across an amazing flatworm -  Pseudobiceros gratus!  This large (1.5") flatworm is characterized by its bold black or dark brown stripe down the middle of its back, distinct black ring and outline along its edges.  Leon witnessed it swimming through the water where it was suddenly seized by a glass anemone (Aiptasia sp.), but he was able to pry it out of the tentacles.

Pseudobiceros gratus flatworm. Leon Weaver image

Flatworms are often mistaken for nudibranchs, aka, sea slugs...

 Dendronotus fumata sea slug. Mark Heckman image

Nudibranchs which means,"naked gill," are in the snail family - they are essentially a shell-less snail, like land slugs. Like other sea snails, they have gills. In the case of the nudibranchs, they have a flower like plume of gills on the back of their body (as can be seen above). They also have two tentacles (rhinophores) up front to sense/smell the water. They glide along the bottom on their muscular foot and some even swim as needed.

The confusion comes when watching a similarly sized flatworm, often brightly colored, with two nuchal tentacles near the front end, gliding along or even swimming like a nudibranch mollusc. But it is not a mollusc - it is a flatworm - just a very large and impressive one.

The following video is a nice depiction of a flatworm swimming mid-water column:

  

Flatworm Video by Zoneku

However, as alike as flatworms and nudibranchs may appear, their relationship mostly ends with being in the Kingdom Animalia.  As human beings, we are programmed to link organisms with similar visual characteristics to other organisms with the same visual traits.  Thankfully, science helps us look more closely to better understand the world around us.

Aloha,
Casey