Reference: Marine Ecology 28 (2007) 199–207 ª 2007 The Authors. Journal compilation ª 2007 Blackwell Publishing Ltd

1. Physiological and behavioral responses of Bathynerita
naticoidea (Gastropoda: Neritidae) and
Methanoaricia dendrobranchiata (Polychaeta:
Orbiniidae) to hypersaline conditions at a brine pool
cold seep
Ahna L. Van Gaest1, Craig M. Young1, John J. Young1,2, Alicia R. Helms1,3 & Shawn M.
Arellano1
PRESENTED BY: DE JESUS, DEL ROSARIO, OLIVAR, UY

2. INNER ZONE:
Bathynerita naticoidea are abundant
High Methane and High Oxygen
Concentrations
High salinity
BRINE POOL
SURROUNDED BY MUSSEL
BED
I
Bathymodiolus childressi
O
OUTER ZONE:
Methanoaricia dendrobranchiata
are abundant
Low Oxygen Concentration SALINITY OF BRINE POOL:
Low salinity 121.35 ~ 120

3. INQUIRY
Under experimental conditions, which between
the two differently distributed species
(Bathynerita naticoidea: outer; Methanoaricia
dendrobranchiata: inner) in a brine pool can
tolerate higher salinities?

5. EXPERIMENT
Legend
Incubating Medium of
Different salinities
Individuals
Salinities:
35, 45, 55, 65, 75 85
Incubation time:
15 hours

6. EXPERIMENT
VS
Salinities:
35, 55, 75,

7. EXPERIMENT
Salinity
75
Weight Initial Weight every hour
6hr incubation

8. RESULTS
120
100
Percent Survival
80
60
40
20
0
35 45 55 65 75 85
Salinities
B. naticoidea M. dendrobranchiata

9. RESULTS
Indication:
Both species are
OSMOCONFORMERS

10. RESULTS
BEHAVIOURAL MECHANISMS THAT ALLOWED SURVIVAL
IN THEIR SPECIFIC HABITATS
Bathynerita naticoidea Methanoaricia
dendrobranchiata
Tight closing of the operculum Exists in large clumps to spread
(seen in salinities 65-85) their collective surface area
across the tops of the mussels in
such a way to remain out of the
Avoid entering salinities higher brine
than 60 (confirmed by halocline
experiment done by authors)

11. CONCLUSION
• B. naticoidea was found to have higher
salinity tolerance compared to M.
dendrobranchiata
• Salinity tolerances do not explain the
differences in the distribution of the 2
organisms
• Behavior is a likely mechanism for
controlling horizontal distribution of this
species across the mussel bed.

12. THANK YOU FOR LISTENING!
AND REMEMBER BEHAVIOUR IS PHYSIOLOGICALLY
IMPORTANT!