Methanotrophic gastropods from a bathyal hydrocarbon seep, Gulf of Mexico

Conference · Wed Jan 01 04:00:00 EST 1992 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5696248

Anderson, L C; Aharon, P; Gupta, S ^[1]

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1. Louisiana State Univ., Baton Rouge, LA (United States)

Two gastropods, Neritina sp. and Truncatella sp., collected live from a Gulf of Mexico active gas seep with the submersible Johnson Sea Link in September 1991, apparently incorporate methane-derived carbon in their soft tissues. Flesh of an individual Neritina sp. had a delta C-13 of [minus]50.92 per mil PDB, and that of two coexisting individuals of Truncatella sp. had values of [minus]45.11 and [minus]49.27 per mil. These isotope values are comparable to those reported for the methanotrophic mytilid bivalve Bathymodiolus sp. from other hydrocarbon seeps on the Gulf of Mexico, and are lighter than published isotopic values of chemosynthetic organisms with sulfur-oxidizing symbionts. The anomalously light carbon-isotopic values of Neritina sp. and Truncatella sp. may steam from one of three causes: (1) these gastropods host symbiotic methanotrophic bacteria, (2) their chief food is methane-oxidizing bacteria present at the seep, or (3) they incorporate some carbon from the periostracum of mussels on which they may graze. The presence of abundant juveniles of Bathymodiolus, reported to settle preferentially in areas of active seepage and high methane release, indicates that methane was abundant and supported a community with multiple trophic levels. Generally, studies of hydrocarbon-seep communities have focused on larger community members, especially bivalves and tube worms. The presence of living Neritina and Truncatella at the authors sampling site, however, draws attention to the fact that these gastropods are integral and significant parts of hydrocarbon-seep communities. Both gastropod species are members of genera that characteristically inhabit shallow marine, intertidal, and semiterrestrial environments. The presence of these genera in bathyal hydrocarbon seeps indicates that they have very broad environmental ranges, thus limiting their utility in paleoecologic reconstructions.

• OSTI ID: 5696248
• Report Number(s): CONF-921058--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 24:7
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030200* -- Natural Gas-- Reserves
Geology
& Exploration
ALKANES
ANIMALS
AQUATIC ORGANISMS
ATLANTIC OCEAN
BIOLOGICAL ADAPTATION
BIOLOGICAL INDICATORS
CARIBBEAN SEA
GEOLOGIC DEPOSITS
GULF OF MEXICO
HYDROCARBONS
INVERTEBRATES
METABOLISM
METHANE
MINERAL RESOURCES
MOLLUSCS
NATURAL GAS DEPOSITS
ORGANIC COMPOUNDS
RESOURCES
SEAS
SEEPS
SURFACE WATERS