Figure 1.
Map of collection sites on the Gulf of Mexico lower continental slope.
The site names are based on Bureau of Ocean Energy Management (BOEM) lease block designations and consist of a two-letter abbreviation, which stands for the region (AC=Alaminos Canyon, for example), followed by a three-digit number. The yellow text gives the name for the region, while the white points and text signify the specific study sites. The notations inside the brackets indicate how many of each community type was collected at a site: C=vesicomyid clams (Calyptogena ponderosa and an undescribed vesicomyid), M=mussels (Bathymodiolus spp.), and V=vestimenitiferans (Escarpia laminata and Lamellibrachia spp.). The bathymetric depth is given in meters below the site name.
Figure 2.
A close-up photo of Protomystides sp. inhabiting its casing atop the obturaculum of Escarpia laminata.
Stoloniferans are also shown attached to the anterior portions of vestimentiferan tubes.
Figure 3.
Patterns in tissue δ13C and δ15N values with depth in Alvinocaris shrimp and vestimentiferans.
(A) The difference between the mean δ13C of Alvinocaris shrimp (δ13Cshrimp) in each collection and the mean δ13C of the vestimentiferan tubeworms in the same collections (δ13Cvest) vs. depth. (B) The difference between the mean δ15N of Alvinocaris shrimp (δ15Nshrimp) in each collection and the mean δ15N of the vestimentiferan tubeworms in the same collections (δ15Nvest). (C) δ13C and (D) δ15N values for each individual Alvinocaris shrimp and vestimentiferan tubeworm sampled vs. depth.
Figure 4.
Mean tissue stable isotope contents of Alvinocaris spp. vs. vestimentiferans by collection.
Mean and standard deviation of (A) δ13C or (B) δ15N contents of the shrimp Alvinocaris spp. in each collection vs. the mean and standard deviation of the tissue δ13C or δ15N contents of the vestimentiferan tubeworms in the same collection. “Deep” collections were collected between 1400 and 2800 m depth and contained only A. muricola, while the “shallow” collections are all from the GC234 study site at 530 m depth and contained only A. stactophila. The dotted line represents equal values on the x- and y-axes.
Figure 5.
Stable isotope values for every individual sampled from the mussel collections from the Garden Banks, Green Canyon and Walker Ridge study sites (1200-1900m depth).
(X.1) δ15N and (X.2) δ34S vs. δ13C, where X = a sequential letter representing a single collection. For example, A.1 and A.2 display the δ15N vs. δ13C and δ34S vs. δ13C, respectively, for one collection, B.1 and B.2, another, and so on. Different animal taxa are represented by different symbols. The site information, collection coordinates, and reference to the quantitative community study [2] are shown in Table 1.
Figure 6.
Stable isotope values for every individual sampled from mussel collections from the Alaminos Canyon and Atwater Valley study sites (2200-2800m depth).
(X.1) δ15N and (X.2) δ34S vs. δ13C, where X = a sequential letter representing a single collection. For example, A.1 and A.2 display the δ15N vs. δ13C and δ34S vs. δ13C, respectively, for one collection, B.1 and B.2, another, and so on. Different animal taxa are represented by different symbols. The site information, collection coordinates, and reference to the quantitative community study [2] are shown in Table 1.
Figure 7.
Stable isotope values for every individual sampled from vestimentiferan collections.
(X.1) δ15N and (X.2) δ34S vs. δ13C, where X = a sequential letter representing a single collection. For example, A.1 and A.2 display the δ15N vs. δ13C and δ34S vs. δ13C, respectively, for one collection, B.1 and B.2, another, and so on. Different animal taxa are represented by different symbols. Protomystides sp. is split into three categories with different symbols representing the habitat the worms were found in. “Protomystides sp. (on E. lam)” represents individuals attached to the obturaculum of Escarpia laminata, “Protomystides sp. (dead tube)” refers to individuals collected inside empty vestimentiferan tubes, and “Protomystides sp. (outside tube) refers to individuals attached to the outside of vestimentiferan tubes. In all cases, the worms had inhabited a thin flexible tube attached to a surface. The site information, collection coordinates, and reference to [2] quantitative community study are shown in Table 1.
Figure 8.
Tissue stable isotope values for the methane ice worm Hesiocaeca menthanicola and Bathymodiolus mussels separated by collection.
(A) δ13C vs. collection, (B) δ15N vs. collection, and (C) δ34S vs. collection. Different symbols are used for different Bathymodiolus species.
Figure 9.
Tissue stable isotope values of paired Protomystides sp. and E. laminata.
Tissue (A) δ13C, (B) δ15N, and (C) δ34S values in the small polychaete Protomystides sp. vs. the paired Escarpia laminata individual upon which the Protomystides sp. was found. The circles with crosses in panel (A) denote tissue δ13C values for paired samples of Protomystides sp. and E. laminata from a single collection from the AT340 study site. The solid lines denote best-fit regression lines; the top one is for all samples and the bottom line for the single collection.
Figure 10.
Paired commensal polychaetes and host symbiotic bivalves.
Tissue (A) δ13C, (B) δ15N, and (C) δ34S values in the commensal polynoid Branchipolynoe seepensis or nautilliniellid polychaete vs. the paired Bathymodiolus heckerae, B. childressi, or vesicomyid clam (Calyptogena ponderosa or an undescribed vesicomyid) individual within whose gills the polychaete was found. The ellipses shown in the figure encircle individuals collected in the same <1m2 area. There are fewer data for δ34S, because some samples did not have enough remaining material after δ13C and δ15N analysis.