New genera and species of Urothoidae (Amphipoda) from the Brazilian deep sea, with the re-assignment of Pseudurothoe and Urothopsis to Phoxocephalopsidae
Author
Sittrop, Daniela J. P.
Author
Serejo, Cristiana S.
Author
Souza-Filho, Jesser F.
Author
Senna, André R.
text
Journal of Natural History
2014
2014-08-31
49
9
527
552
journal article
10.1080/00222933.2014.953227
d48e028f-1b68-41ca-b206-57a747b8a894
1464-5262
4004001
Family
UROTHOIDAE
Bousfield, 1978
Haustoriidae
(in part) –
Chevreux and Fage 1925: 91
, figs 90–95;
Gurjanova 1951: 328
, figs 210–212;
Lincoln 1979: 312
, figs 154–156;
Bellan-Santini 1989: 365
, figs 257–264.
Urothoidae
(in part)
Bousfield 1978: 356
.
Urothoidae
Barnard and Karaman 1991: 726
.
Diagnosis
(modified from
Barnard and Karaman 1991
).
Head short, rostrum weak, anteroventral angle well developed and projected ventrally. Antenna 1, peduncle with articles elongated, geniculate between articles 2 and 3, flagellum short. Antenna 2 strongly sexually dimorphic in most taxa; article 4 weakly expanded, stout setae absent or in setal rows; article 5 slightly shorter and more slender than article 4; flagellum variable in length, commonly short in females and elongated in males. Upper lip dominant in size, epistome slightly distinct. Mandible short and stout, incisors smooth or weakly spinose; accessory setal row weakly developed or absent; palp 3-articulate, article 3 apically rounded. Lower lip, outer lobes well developed. Maxilla 1, inner plate with fewer than six setae; palp 2-articulate. Maxilla 2 inner and outer plates subequal in length. Maxilliped palp 4-articulate, article 2 expanded or nasiform, article 4 unguiform to clavate, commonly setose, apical nail weakly developed. Gills at pereonite 2 to 6, oostegites slender. Gnathopods 1 and 2 slender, similar to each other, ischium short, carpus elongate. Pereopods 3–5 carpus well developed. Pereopods 6–7 similar or developed in phoxocephalid form, with pereopod 7 shorter than pereopod 6, with basis posteriorly expanded. Epimeral plate 3 dominant in size. Uropod 3 peduncle short, flat and expanded; outer ramus 2-articulate, dominant in size. Telson cleft.
Type
genus
Urothoe
Dana, 1852
Composition
Carangolia
Barnard, 1961
;
Carangolioides
gen. nov.
;
Coronaurothoe
gen. nov.
;
Cunicus
Griffiths, 1974
;
Urothoe
Dana, 1852
; and
Urothoides
Stebbing, 1891
.
Removed genera
Pseudurothoe
Ledoyer, 1986
and
Urothopsis
Ledoyer, 1967
are transferred here to
Phoxocephalopsidae
Barnard and Clark, 1982
.
Remarks
Until now, the family
Urothoidae
included three monotypic genera:
Cunicus
,
Pseudurothoe
and
Urothopsis
; the last two genera are now removed to
Phoxocephalopsidae
.
Carangolia
comprises four described species,
Urothoides
10 species and
Urothoe
, which is the most speciose, 44 species. Most taxonomic studies dedicated to this group in the past commonly have neither illustrations nor descriptions of mouthparts. In this study, we detail these structures, which have become essential for the separation of the species, and which have been used to establish the two new genera described herein. Another important aspect of urothoid taxonomy is that only a small number of structures have been illustrated and often the descriptions are short or poorly detailed, as in
Chevreux and Fage (1925)
,
Gurjanova (1951)
,
Lincoln (1979)
and
Bellan-Santini (1989)
, making it difficult to recognize the species. The biggest taxonomic problem in the family
Urothoidae
involves the genus
Urothoe
, because it has a large number of species and some variation in the character states. In the original description of
Dana (1852)
only a few features were used, including: gnathopods 1 and 2 slender, subchelate, and similar; antenna 1 shorter than antenna 2; maxillipeds long and slender, with inner plate small; uropod 3 rami foliaceous; and telson deeply cleft. Only the uropod 3 with foliaceous rami is an exclusive feature of the genus, which makes it a weakly defined group. Many species displaying features described above were grouped into
Urothoe
, resulting in a taxon with wide morphological variation. These facts suggest that
Urothoe
might be, actually, a non-monophyletic group. Currently,
Urothoe
is in great need of an extensive revision, and a more restricted diagnosis for it must be established. Still, in this work it has been possible to establish two new genera supported by clear and well-defined characters. The diagnostic characters of the genera included in
Urothoidae
are presented in
Table 1
.