Morphotype Analysis of Deep-Sea Benthic Foraminifera from the Northwest Gulf of Mexico

Abstract

An analysis of benthic foraminiferal morphotypes, based on test shape, mode of coiling and presence or absence of surface pores, was carried out on benthic foraminiferal data collected from the Gulf of Mexico by Phleger (1951). The morphotypes show distinct depth patterns and are used to determine the depth distribution of foraminiferal microhabitats in the Gulf of Mexico. The plano-convex morphotype has generally low values ({le}10%) in relatively shallow depths ( 1,000 m). The biconvex morphotype has values of 2,000 m, with the 1,300-2,000 m interval being transitional with variable values. The infaunal-epifaunal depth pattern is similar to that observed in the Norwegian Sea. The infaunal-epifaunal transition between 1,300 and 2,000 mmore » is close to the upper or lower depth limits of many species, and the authors suggest that these depth limits are related in part to the microhabitat preferences of the taxa.« less