The Isopods of Abyssal Depths in the Atlantic Ocean

In this monograph 176 species are described. Prior
to this work only 66 species were known from the
Arctic-Atlantic below 2000 meters and only 143 were
known from the abyss of the world oceans, excluding
probably pelagic species. This means that the results
of this work based upon 84 abyssal trawl samples
taken by the R.V. Vema and M.V. Theta increase
by roughly one-fifth the number of abyssal species
known for the entire world in the order Isopoda. The
number of species from the Atlantic, where the fauna
was best known previously, is increased by over two
times. One hundred and seven new species are
described from the Atlantic abyss and near abyss for
the first time. Species new to the abyss but previously
known elsewhere, are Antennuloniscus dimeroceras
Barnard), Stylomesus inermis (Vanhoffen), Nannoniscus
oblongus G. O. Sars, Eurycope antarctica Vanhoffen, and
Eurycope vicarius Vanhoffen. Additionally five species
previously recorded from the Atlantic abyss are
excluded from this monograph due to the fact that
they are too poorly known. These are Eurycope
SUMMARY
abyssicola Beddard, Acanthocope acutispina Beddard,
Eurycope sp., Ischnomesus bacillus Beddard, and Storthyngurafragilis
(Beddard). The list of the new species
is contained in the table of contents.
A total of nine new genera is described. These are
Antennuloniscus (formerly part Haploniscus), Dendromunna,
Spinianirella, Notoxenoides, Xostylus, Abyssijaera,
Mesosignum, Glabroserolis, and Vemathambema. This
brings the known abyssal Atlantic genera to 41 when
one adds the five genera that were previously known
from Atlantic shallow water and are reported herein
from the abyss, Leptanthura, Antarcturus, Acanthomunna,
Nannoniscoides, and Stylomesus.
Where possible analytical keys are given to the
species (world) of each genus; partial keys are given
to the species of Gnathia and Eurycope, and no key is
given to the poorly defined genus Ilyarachna.
It is intended that the zoogeographic, ecologic, and
phylogenetic relationships of these collections will be
subject to analytic study in the second part of this
monograph.