Holothuroidea of the Charlie Gibbs Fracture Zone area, northern Mid-Atlantic Ridge

Abstract

Holothurians are among the most species-rich taxa in the megabenthos on the northern Mid-Atlantic Ridge at depths of 2200Á3700 m. Extensive new collections of 32 holothurian species were made in 2007Á2010 in the Charlie Gibbs Fracture Zone area as part of the ECOMAR project. New material includes samples taken using a trawl and the ROV Isis. Samples and in situ observations from the ROV were of particular value because the morphological details of a number of holothurian species could be clarified. Many of these species are gelatinous and fragile and were damaged in trawls. Three species of elasipodid holothurians are described as new to science. An annotated check-list of all species of deep-sea holothurians collected in the Charlie Gibbs Fracture Zone area is provided. The checklist includes synonyms, distribution data and morphological descriptions as well as photographs taken in situ and in vivo. Ecological remarks are given for some species.

Benthic megafauna on steep slopes at the Northern Mid‐Atlantic Ridge

“…; Rogacheva et al . ). Here, ROV imagery was used to characterize the megafaunal assemblages and the sea‐bed habitat of areas of steep slope on the MAR that had large areas of hard substratum.…”

“…Video imagery is a well-established tool for characterizing benthic biology and has been used widely at the MAR (Alt 2012;Beazley et al 2013;Bell et al 2013;Gebruk & Krylova 2013;Rogacheva et al 2013). Here, ROV imagery was used to characterize the megafaunal assemblages and the sea-bed habitat of areas of steep slope on the MAR that had large areas of hard substratum.…”

Deep-sea echinoids and holothurians (Echinodermata) near cold seeps and coral communities in the northern Gulf of Mexico

“…The genus has previously been reported from the Gulf of Mexico in depths of 408-617 m (Pawson et al 2009); the current image was taken at the much greater depth of 2115 m. According to the synonymy provided by Rogacheva et al (2013), this individual may be Bathyplotes natans (M. Sars), which is known from the Atlantic and Pacific oceans in 193-2750 m.…”

“…Based upon the general morphology of this species, and perhaps in part upon the suggestion of Gage et al (1985) that this species may be neutrally buoyant, Rogacheva et al (2013) concluded that it was capable of swimming. The present records (Fig.…”

“…For recent examples, see Hoving and Vecchione (2012) and Pietsch et al (2013) for GOM squid and fishes, respectively. For the echinoderms, numerous publications, such as those by Heezen and Hollister (1971), Pawson (1976Pawson ( , 1982, and more recently Bluhm and Gebruk (1999), Gebruk (2008), and Rogacheva et al (2013), have revealed much about the autecology and synecology of deep-sea echinoderms. Ideally, imagery might be accompanied by specimens, but even when imagery alone is available, much can be learned.…”