In lieu of an abstract, here is a brief excerpt of the content:

Shelled protists of the Class Foraminifera (Phylum Granuloreticulosa ) living in the Gulf of Mexico (GMx) have been studied since the 1890s (see Cushman 1918), but when Fred Phleger and Frances Parker wrote their chapter for Fisheries Bulletin 89 (Phleger and Parker 1954), much of the information came from their own extensive work. Their table of benthic taxa (reproduced from Phleger 1951) contained 113 named species and varieties , 4 species with uncertain trivial names, and 6 species with only generic names. In addition, they gave a list of 16 planktonic species. After half a century of data gathering by numerous workers, our checklist includes 919 benthic and 32 planktonic species. The first major post-1950s compilation of published species distribution data in the Gulf of Mexico (GMx) (Culver and Buzas 1981) was a component of a monumental literature survey of benthic foraminiferal species distribution in the seas around North America. Most of the 848 species in the Culver and Buzas list are included in ours, but there are important differences between the 2 compilations because of (1) nomenclatural changes prompted by recent research, (2) disagreements on synonymy , (3) different approaches regarding the inclusion of some species names (see the following), (4) slightly different geographic limits chosen for the region covered , and (5) new species reported in the past 25 years. All GMx data in our checklist, whether on depth or areal distribution, are taken from primary sources. Because of space limitations, however, only selected references have been cited. For revisions of many species names, we have used the opinions of Barker (1960), Loeblich and Tappan (1987, 1994), and Jones (1994). The suprageneric classification used in this chapter is based on Loeblich and Tappan (1987), with modifications taken from Loeblich and Tappan (1992, 1994), Revets (1996), Sen Gupta (1999), and Kaminski (2004). As in Phleger and Parker (1954), all species in our checklist are morphospecies; that is, the taxonomy is based entirely on shell morphology. Only definitely identified species are included in the list. Names with “cfs,” “affs,” or question marks were excluded. This affects especially the species list in the classic work by Norton (1930), where 30 GMx taxa were reported as “sp. cf.;” these occurrences were used by Culver and Buzas (1981) but not by us. Foraminiferal species, in general, are widely distributed . Notwithstanding excessive taxonomic splitting and inadequate sampling coverage in many ocean basins, this distribution partly supports the hypothesis of “ubiquitous dispersal” of protistan species (e.g., Finlay and Esteban 2001). Using the standard ecological definition of endemism —that is, restriction to a single geographic region (e.g., Lincoln, Boxshall, and Clark 1998)—we recognized only 35 endemics among the benthic species and none 87 6 Foraminifera of the Gulf of Mexico Barun K. Sen Gupta, Lorene E. Smith, and María Luisa Machain-Castillo  Foraminifera. After Chapman 1902. 88 ~ Foraminifera major hindrance to the estimation of habitat depth limits . We have taken a conservative approach to this estimation by (1) excluding some strikingly disjunct depth occurrences (especially of well-known species), and (2) using the comments of authors regarding displaced Foraminifera in their material (e.g., Phleger and Parker 1951). Even then, the real maximum depth for many species in our list may be much less than what we have entered. The depths are given in meters, except where they are unreported by the observers; a few depths are given as “shelf” or “shallow,” because that is how they were reported. All depth ranges in the checklist are just for GMx. A few species are known only from upheaved mudlump sediment (Lankford 1959, Andersen 1961); their habitat water depths are unknown. These mudlump occurrences are indicated in the checklist. Overall, the documentation regarding microhabitats and adaptive strategies is unsatisfactory for GMx benthic foraminifers, but we use the following designations for some species: (1) intertidal and/or marsh; (2) bathyal and/or abyssal (habitat depth greater than about 200 m, but rare GMx bathyal species occurring in much shallower waters elsewhere are not given this label); (3) sessile (only for species firmly attached to substrate); (4) meroplanktonic (all, except one, with a float-chamber stage); and (5) endosymbiont (species with algal endosymbionts). Planktonic foraminiferal species (Order Globigerinida ) are widespread in world oceans, a few being nearly ubiquitous in open marine waters. High abundances of most species, however, are limited to particular east-west (crudely latitudinal) biogeographic belts (e.g., Bé 1977, Kennett and Srinivasan 1983, Hilbrecht 1996, Arnold and Parker 1999). In spite of some pronounced differences in...

Share