Taxonomic review of the family Discodorididae (Mollusca: Gastropoda: Nudibranchia) from Brazil, with descriptions of two new species
Author
Alvim, Juliana
Author
Pimenta, Alexandre Dias
text
Zootaxa
2013
3745
2
152
198
journal article
10.11646/zootaxa.3745.2.2
c32092a5-be17-4b13-8c8b-a7b1e7b334a8
1175-5326
248699
D87FBB64-5DE2-4D19-9338-6E9BE212FAEF
Taringa iemanja
sp. nov.
(Figures: 2G–H; 25–26)
Type
material.
Holotype
: MNRJ 13180, P.M. S. Costa leg., 15.0 mm preserved length [dissected].
Type
locality.
Bacia de Campos (22°06'9875"S–40°10'8204"W), Rio de Janeiro state,
Brazil
,
150 m
depth.
Etymology.
Taringa
is derived from an Aboriginal word meaning “strong”. "
Iemanjá
" (Yoruba expression "Yèyé omo ejá", which means mother whose children are fish) is an African deity who represents the queen of the sea.
Diagnosis.
Radula with innermost lateral teeth having three denticles on their outer side, first denticle is tiny. Deferent duct long, narrow and convoluted, near opening presenting a ring-shaped and smooth cuticle. Bursa copulatrix large and sherical, not flattened, covering practically entire reproductive system.
Description. External morphology
(
Figures 2
G–H; 25E): body oval, slightly depressed, 15.0 mm long in a preserved specimen, with two times greater length than width. Mantle densely covered by equidistant caryophyllidia; caryophyllidia lower at mantle edge and in center of mantle (48 µm–50 µm) than those on sides of mantle (100 µm–110 µm), with variable number of spicules protruding around tubercle; tubercle apex with a ciliary tuft, elongated and oval. Rhinophoral sheaths moderately high and irregular covered by caryophyllidia of same size of those in centre of mantle. Rhinophores long with cylindrical apex, 12 diagonal perfoliations. Branchial sheath low with lobulated edge. Gill with six retractile, tripinnate branchial leaves, arranged symmetrically at longitudinal axis of body; anal cone high, located between two most posterior branchial leaves. Foot narrower than mantle, anteriorly bilabiated and notched on two lips. Oral tentacles triangular. Preserved specimen presenting mantle coloration orange-brown in edges and center, and with predominance of reddish brown on sides of mantle; mantle edge with white blotches; rhinophores with chestnut-colored perfoliations with white blotches and white apex; branchial leaves in proximal part translucent yellow and distal part brownish; ventrally body is yellowish, side of foot with brownish circular blotches.
Labial cuticle and radula
(
Figures 25
A–D): labial cuticle smooth. Radula formula
29 x 3
–4.34-35.0.34-35.3–
4 in
preserved specimen measuring 15.0 mm in length; innermost lateral teeth hook-shaped with three denticles on outer surface, first denticle smaller than others, and with one protuberance on inner surface; subsequent lateral teeth hook-shaped with only external denticles increasing in number outwards (up to 7); 3–4 marginal teeth spatulate and non-pectinate.
Reproductive system
(
Figures 25
F–26): hermaphrodite duct connecting to long and slightly convoluted ampulla. Postampullary gonoduct short, connecting to oviduct and prostate. Prostate granular and rounded, divided into two parts; proximal part smaller, whitish, less dense, and distal part larger, yellowish, denser. Vas deferens long, narrow and convoluted, opening into common atrium with vagina; vas deferens near gonopore presenting a ring-shaped and smooth cuticle. Vagina elongate, narrow and opening into bursa copulatrix. Bursa copulatrix large and rounded/spherical, covering almost entire reproductive system. Bursa serially arranged, convoluted vaginal duct connecting to small-stalked seminal receptacle. Uterine duct very short. Seminal receptacle with 1/5 of diameter of bursa copulatrix.
Remarks.
The single specimen studied here fits perfectly in the genus
Taringa
, presenting all the diagnostic features of this genus (Er. Marcus, 1955), including the dorsum covered by elongated caryophyllidia (
Fig. 25
E); tripinnate gill; smooth labial armature (
Fig. 25
A); radula without rachidian teeth and with hook-shaped lateral plates bearing denticles on outer side (
Figs. 25
B–D); prostate divided into two parts (Fig. 26), and a penis with cuticular structure (
Fig. 25
F).
FIGURE 25
.
Taringa iemanja
sp. nov.
, SEM photographs (MNRJ 13180); A, detail of the labial cuticle; B, first lateral tooth, the first tiny denticle indicated by white arrow; C, midlateral teeth; D, marginal teeth; E, caryophyllidia; F, penial cuticle.
According to
McDonald
(2009), and considering
Taringa telopia
and
Taringa disa
as distinct species (see remarks relating to
Taringa telopia
), there are 14 valid species in the genus
Taringa
, of which three are reported from the Western Atlantic:
T. telopia
,
T. disa
and
Taringa tritorquis
Ortea, Peréz & Llera, 1982
, the latter from
Costa Rica
,
Cuba
and the Azores.
As
indicated by the table presented by García-Gómez
et al.
(1993),
T. iemanja
sp. nov.
differs from
Taringa tritorquis
in that the latter species possesses smooth rhinophoral sheaths with 6–8 lobes, whereas the sheaths in
T.iemanja
sp. nov.
are irregularly covered by caryophyllia. The cuticular structure of the penis was not described for
T. tritorquis
, therefore we could not compare this feature.
T. telopia
and
T. disa
are clearly distinct from
T. iemanja
sp. nov.
in that the cuticular structure of the penis in these species is cylindrical, whereas in
T. iemanja
sp. nov.
it is ring-shaped.
Taringa telopia
is the most similar species to
T. iemanja
sp. nov.
, but differs in its almost complete lack of pigmentation in preserved specimens;
T. iemanja
sp. nov.
, on the other hand, has maintained coloration of the orange-brown mantle with white blotches on the mantle edge in preserved specimens (
Fig. 2
G). Furthermore, the color of the rhinophores and gill of
T. iemanja
sp. nov.
was found to be different from that of
T. telopia
. In live specimens of
T. telopia
, the color of the rhinophores and gill is uniformly beige, whereas in the preserved specimen of
T. iemanja
sp. nov.
the rhinophores are chestnut with white blotches and a white apex; furthermore, the branchial leaves in the proximal part are translucent yellow and those in the distal part are brown. The external face of the innermost lateral tooth of
T.iemanja
sp. nov.
presents three denticles, one of which is tiny (
Fig. 25
B), whereas
T. telopia
presents only one or two denticles on the outside of the innermost lateral tooth (
Figs. 23
A–B). We cannot assess the diversity of the inner surfaces of the innermost lateral teeth of
T.iemanja
sp. nov.
relative to that of
T. telopia
(
Figs. 23
C–E), because we obtained only one specimen of the former species. The outermost lateral tooth of
T.iemanja
sp. nov.
is spatulated and non-pectinate (
Fig. 25
D), whereas in
T. telopia
it is spatulated and pectinate (
Fig. 23
F). Additionally, the deferent duct is convoluted in
T.iemanja
sp. nov.
(Fig. 26); however, in
T. telopia
it is short and straight (
Fig. 24
). Finally,
T.iemanja
sp. nov.
presents a bursa copulatrix that is proportionately longer and larger in volume (Fig. 26), covering practically the entire reproductive system, than that of
T. telopia
(
Fig.24
).