Physiological and behavioral responses of Bathyneritanaticoidea (Gastropoda: Neritidae) and Methanoaricia dendrobranchiata (Polychaeta:

Orbiniidae) to hypersaline conditions at a brine pool

cold seepAhna 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

I

O

INNER ZONE:

Bathynerita naticoidea are abundantHigh Methane and High Oxygen ConcentrationsHigh salinity

OUTER ZONE:

Methanoaricia dendrobranchiataare abundantLow Oxygen ConcentrationLow salinity

SALINITY OF BRINE POOL: 121.35 ~ 120

BRINE POOL SURROUNDED BY MUSSEL BEDBathymodiolus childressi

I N Q U I R Y

Under experimental conditions, which betweenthe two differently distributed species(Bathynerita naticoidea: outer; Methanoariciadendrobranchiata: inner) in a brine pool cantolerate higher salinities?

E X P E R I M E N T

Legend

Incubating Medium of Different salinities

Individuals

Salinities: 35, 45, 55, 65, 75 85Incubation time:15 hours

E X P E R I M E N T

Salinities:35, 55, 75, VS

E X P E R I M E N T

Salinity 75

Weight Initial Weight every hour6hr incubation

R E S U L T S

0

20

40

60

80

100

120

35 45 55 65 75 85

Pe

rce

nt

Surv

ival

Salinities

B. naticoidea M. dendrobranchiata

R E S U L T S

Indication:Both species are OSMOCONFORMERS

R E S U L T S

Bathynerita naticoidea Methanoaricia dendrobranchiata

Tight closing of the operculum(seen in salinities 65-85)

Exists in large clumps to spread their collective surface area across the tops of the mussels in such a way to remain out of the brineAvoid entering salinities higher

than 60 (confirmed by halocline experiment done by authors)

BEHAVIOURAL MECHANISMS THAT ALLOWED SURVIVAL IN THEIR SPECIFIC HABITATS

C O N C L U S I O N

• B. naticoidea was found to have highersalinity tolerance compared to M.dendrobranchiata

• Salinity tolerances do not explain thedifferences in the distribution of the 2organisms

• Behavior is a likely mechanism forcontrolling horizontal distribution of thisspecies across the mussel bed.

THANK YOU FOR LISTENING!AND REMEMBER BEHAVIOUR IS PHYSIOLOGICALLY

IMPORTANT!