Deep-sea tardigrades in the northern Gulf of Mexico with a description of a new species of Coronarctidae (Tardigrada: Arthrotardigrada), Coronarctus mexicus

During May and June 2000, for the first time, benthic samples were collected from 43 stations in the northern Gulf of Mexico deep sea that included seven transects along the northern continental slope and abyssal plain ranging in depth from 625 to 3159 m. A total of 54 tardigrades (36 identified) were extracted from samples, ranging in depth from 625 to 3150 m. Collected tardigrades belong to five genera and represented eight species, Angursa bicuspis abyssalis (two specimens from 1401 and 2020 m depth), four species of Coronarctus (29 specimens from 625 to 3159 m depth), Euclavarctus convergens (one specimen from 2743 m depth), E. thieli (one specimen from 2635 m depth), Proclavarctus sp. (one specimen from 2600 m depth), Styraconyx sp. (two specimens from 1565 and 2600 m depth). The most abundant genus was Coronarctus (80.5% of identified species) and was present in most areas sampled with the exception of the central and Mississippi trough regions and comprised four species, Coronarctus laubieri (15 specimens), C. stylisetus (one specimen), C. disparilis (three specimens) and a new species C. mexicus (10 specimens). Tardigrades were mostly found in the western regions (NW, W, WC) and in deep waters, 2290 m average depth. Analyses of tardigrade and depth collected gave a slight positive correlation (R2 = 0.029), while analyses of tardigrade and degrees longitude resulted in a slight negative correlation (R2 = 0.022).