The Deep-sea Fish Fauna of the Northern Gulf of Mexico

Abstract

As a part of the Deep Gulf of Mexico Benthos (DGoMB) project, fishes were sampled in May and June 2000. 46 stations were occupied using a 41' semi-balloon otter trawl along transects which ran from shallow to deep water and from northern Florida to off southern Texas. 1073 individuals in 121 demersal fish species were taken. Cluster analyses showed the fish fauna is zoned with depth. Assemblages were identified on the shelf (188-216 m), upper slope (315-785 m), mid-slope (680-1359 m), lower slope (1780-2460 m), and the rise (2248-3075 m). The most abundant species found on the shelf was the small caproid Antigonia capros. Deeper, the fauna is dominated by Macrouridae: Bathygadus macrops and Caelorinchus caribbaeus on the upper slope and Nezumia cyrano and N. aequalis at midslope. The lower slope and rise are dominated by Ophidiidae: Dicrolene kanazawai and Acanthonus armatus respectively. Species richness is highest on the upper slope (53 species) and decreases with depth; the rise has 17 species. Abundance, too, is greatest on the upper slope, especially in the Mississippi Trough and DeSoto Canyon, and declines greatly with depth. Data on fishes support DGoMB hypotheses relating to depth zonation and eastwest abundance, but, because of limited samples, are inconclusive for others. There do not appear to be species of commercial interest in the deep demersal fish fauna.