Polychaeta Orbiniidae from Antarctica, the Southern Ocean, the Abyssal Pacific Ocean, and off South America
Author
Blake, James A.
text
Zootaxa
2017
4218
1
1
145
journal article
37318
10.5281/zenodo.245827
69cf893c-7b35-48e8-ad78-d9775626f287
1175-5326
245827
9345C596-8656-4B5C-AD8C-2FACF4E9240C
Genus
Phylo
Kinberg, 1866
Type-species:
Phylo felix
Kinberg, 1866
, by monotypy.
Diagnosis.
Prostomium pointed on anterior margin; peristomium with one achaetous ring. Branchiae first present from setiger 5–7. Posterior thoracic segments with several postsetal lobes and subpodial lobes (at least five of each type) together usually forming ventral fringe. Thoracic neurosetae including blunt uncini and crenulated capillaries; posterior thoracic segments with modified spearlike spines. Flail setae present or absent in posterior abdominal notopodia.
Remarks.
Species of
Phylo
are closely related to species of
Orbinia
and differ chiefly in having the thoracic region divided into anterior and posterior regions; the posterior region bears modified spines. Phylogenetically, the modified thoracic spines are apomorphic rather than plesiomorphic but provide species of
Phylo
with an obvious and practical distinctness that makes them easy to identify. Because of this character,
Phylo
is retained as a genus, although subgeneric rank with
Orbinia
might be preferred by some investigators. Ten species of
Phylo
were reviewed by
Hartman (1957)
, who provided detailed descriptions for three, including the
type
species,
P. felix
Kinberg. Additional
species have been described by
Day
(1961
;
1977
),
Wu
(1962)
,
Mohammad
(1970)
, and
Hartmann-Schröder
&
Rosenfeld
(1990)
.
Phylo felix
was encountered in the present study and appears to be limited to
South America
and the Antarctic Peninsula.
Orbinia (Phylo) minima
described from the
Antarctic Peninsula
by
Hartmann-Schröder
&
Rosenfeldt
(1990)
is represented only by small specimens but agrees well with
P. felix
.