Mail Buoy
April 13, 2001
Hey there!
I hope life is great out there in the Indian Ocean. I was just curious to know what some characteristics of the hairy run-a-way snails that you observed were.
I’m sending you all good vibes from the land of MA.
Cameron Lash
The Waring School, Beverly, Massachusetts
Hi Cameron
Thanks for the great question! So far we’ve seen 4-5 species of snails, 2 of them being the very large snails involved in the escape attempt.
For starters, the interesting thing about snail species as a whole is that they play a variety of roles in the food web at hydrothermal vents. Some are predatory and feed on other animals, some feed on the bacterial mats that form on the surface of the rocks and chimneys, and some are scavengers that feed on anything they can find.
Another very interesting food source for the hairy snails in particular is internal bacterial symbionts. In general, snails use gills like we use our lungs, to take up oxygen. However, unlike other snails, the hairy snails also use their gills as a large tissue in which to house bacteria that live inside of them and help to nourish the animal. We are not sure how much the snails actually feed by themselves (they have a very reduced digestive tract) or if they rely completely on their internal bacterial partners to feed them (like some of the other animals do, including clams and tubeworms, which we have not yet found at the Indian Ocean site).
It is common at vent sites to find many invertebrates that have formed symbiotic associations with bacteria. These partnerships appear to be very successful based on the fact that these animals usually make up a large percentage of the biomass measured at vents. As for the hairs on these snails, we think they’re mostly ornamental, although they may be involved in sensing each other. For example, a snail could feel its neighbors by touching the hairs of other snails with its foot. The other large species we collected has numerous scales on its muscular foot, which they use for movement, giving it the appearance of lizard skin. We are not sure of the purpose of the scales, although they’re very strange and may be unique to this species. Many of these snails have reduced or absent eyes and rely on sensory tentacles to detect food, predators, etc. Unlike typical marine snails, vent snails like warm temperatures, and we collected many of ours near chimney openings with temperatures as high as 13-15°C. That’s pretty warm considering most snails live around 2°C.
Thanks for following the website. We’re having a great time and hope to collect more crazy critters in a few more days.
Shana Goffredi
Hi! We are in College Station, Texas (the home of Texas A&M University - any Aggies out there???) and have a few questions for you. We have been following your cruise and think it’s really great!
1) How are the shrimp (and the other creatures) able to withstand the extremely hot water pouring out of the smoker? On one of the videos it looked like the shrimp were right in the water pouring out of the vent. Do they have some special physiological adaptations to be able to do that?
2) (This question was asked by several of the boys in the class!!) Are the shrimp edible and if so, has anyone on the ship eaten any?
Thank you so much - we plan on using our GPS units tomorrow to see how long it would take us to walk to your location - if that were possible! We’ll let you know as soon as we figure it out!
Mrs. Fechhelm’s classes (127 students)
Hello to Mrs. Fechhelm’s classes in College Station!
I have been to College Station many times to the headquarters of the Ocean Drilling Program at Texas A&M University, so I know it well!
Now to answer your questions:
1) The animals are mostly living in warm water. They do not live in the hot water gushing from the vents. We have seen some shrimp with black patches on their exoskeletons where perhaps they have got too close to the hot water and got burned.
It is important to remember that, although the water coming out of the vents is very hot -- maybe 350°C -- it rapidly mixes with the cold seawater. So the animals generally live in areas where the temperatures may be 20°C or less. On this trip, we measured the temperature of the outside of one of the chimneys and it was between 5 and 11°C -- even though the fluid coming out was over 300°C.
2) Cindy Van Dover tells me that years ago, she boiled a shrimp in a beaker in the lab and ate it. She said it was awful -- a texture like rubber bands and tasted like sulfides. She and I have analyzed the contents of shrimps’ stomachs, and they are also full of sulfides. So -- even though they look plentiful, I don’t think this is a food source of the future!
Thanks for the questions!
Susan Humphris
Hi. My name is Sarah Diehl from John and Neil’s “The Oceans” class at the Waring school. I was wondering, what role the students on your ship play in your voyage?
Thank you for answering my question!
Hello Sarah:
Most of the students who are out here are graduate students who came with their professors to participate in the research and learn about doing fieldwork at sea. We also have one undergraduate, Jessie Philley, who is from the University of Oregon and will graduate with a degree in biology this spring. She took some classes with Anna Louise Reysenbach at Portland State, and is out here helping Anna Louise with her research. Jessie will be applying to study Pharmacy next year, but thought this a great opportunity to experience research at sea.
Apart from working with their professors, the students also help with watch standing and logging data. It is always good to have students at sea -- they are the next generation of scientists!
Hope that answers your question.
Susan Humphris
Hi,
Woods Hole have conducted a lot of research on Mid-Ocean ridges and their geological and ecological characteristics. These are areas of new plate formation and the research has provided a lot of information which has helped in developing the understanding of plate tectonic theory. Are there any plans to conduct research at destructive plate margins, such as the subduction zone off western South America, in order to develop our knowledge of this environment?
Sonia Wall
Teacher of Geography
St. George’s School, Edinburgh
Scotland
Hi Sonia:
Dan Fornari here on RV Knorr replying to your good question about whether there are plans to study active margin environments using deep submergence vehicles. In fact, there are several large research programs in the US and elsewhere that are starting to focus on both passive and active convergent plate margins. These areas have great potential impact on society. For example, cities located near active margins, such as the coast of western South and Central America and the NW coast of the US, can be dramatically affected by seismic and volcanic events triggered by convergent plate margin processes.
The US National Science Foundation is in the process of establishing the MARGINS program which is a long-term research effort to better understand not only active margins, but also passive margins, such as the east coast of the US and western Europe.
Because the depths of some of the active areas of plate margins reach 5000-7000 meters, it is likely that ROV systems like Jason will play a large role in exploring the seafloor in those areas.
Thanks for your good question and I hope the above information is useful to you. We hope you are enjoying Dive and Discover with us. Please extend my warmest regards to your Dad, Frank. All the DSOG ROV team on board send him our best wishes and hold him in the highest regard for his work with WHOI and NSF on deep submergence research and exploration programs.
Best Regards,
Dan Fornari
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