Seven new " cryptic " species of Discodorididae (Mollusca, Gastropoda, Nudibranchia) from New Caledonia
Author
Innabi, Julie
Department of Biological Sciences, California State Polytechnic University Pomona, 3801 West Temple Avenue, Pomona, California 91768, USA
Author
Stout, Carla C.
Department of Biological Sciences, California State Polytechnic University Pomona, 3801 West Temple Avenue, Pomona, California 91768, USA
Author
Valdes, Angel
https://orcid.org/0000-0002-2347-4896
Department of Biological Sciences, California State Polytechnic University Pomona, 3801 West Temple Avenue, Pomona, California 91768, USA
aavaldes@cpp.edu
text
ZooKeys
2023
2023-03-07
1152
45
95
http://dx.doi.org/10.3897/zookeys.1152.98258
journal article
http://dx.doi.org/10.3897/zookeys.1152.98258
1313-2970-1152-45
D20AFC88096345FEA8B074D00728424F
7CD89C59351C5B439C82F9AEEA86CC51
Jorunna daoulasi
sp. nov.
Figs 8A-C
, 9A
, 10A, B
Jorunna
?
Jorunna
sp. 10:
Gosliner et al. 2018
: 122.
Rostanga
?
Rostanga
sp. 4:
Nakano 2018
: 263.
Type material.
Holotype
: In front of the harbor, Koumac, New Caledonia (
20°35.3'S
,
164°16.4'E
), 6 m depth [Koumac 2.1 stn. KR220], 17 Nov 2018, 12 mm long, (MNHN IM-2013-86230).
Other material examined.
In
front of the harbor,
Koumac
,
New Caledonia
(
20°35.3'S
,
164°16.4'E
),
6 m
depth
[Koumac 2.1 stn. KR220],
17 Nov 2018
,
1 specimen
24 mm
long, dissected (MNHN IM-2013-86220). Koumac,
New Caledonia
(
20°35.2'S
,
164°16.3'E
),
6 m
depth
[Koumac 2.3 stn. KR886],
21 Nov 2019
,
1 specimen
27 mm
long, dissected (MNHN IM-2013-86219, isolate JI22)
.
Description.
Body oval, narrow, elongate, completely covered with numerous caryophyllidia (Fig.
8A-C
). Branchial and rhinophoral sheaths low, simple, circular; gill composed of nine short, tripinnate branchial leaves, imbricated, arranged upright, with the apices close to each other in the living animal. Rhinophores short, lamellated, with eight or nine lamellae. Body color grey, with a complex network of white lines of different thicknesses; in some specimens some of the lines are very thick and contain darker areas (Fig.
8A
), whereas in others thicker lines form the main network and thinner lines form a secondary network (Fig.
8
) and in others all lines are approximately the same thickness (Fig.
8B
). Rhinophores and branchial leaves are the same color as the dorsum but the rhinophoral lamellae and in some cases the gill lamellae are white.
Figure 8.
Photographs of live animals of the genus
Jorunna
Bergh, 1876
A-C
Jorunna daoulasi
sp. nov., MNHN IM-2013-86219 on black background (
A
), MNHN IM-2013-86220 in situ (
B
), Holotype (MNHN IM-2013-86230) in situ (
C
)
D-F
Jorunna hervei
sp. nov., MNHN IM-2013-86228 on black background (
D
), MNHN IM-2013-86224 and Holotype MNHN IM-2013-86225 in situ with egg mass (
E
), MNHN IM-2013-86226 in situ with egg mass (
F
).
Reproductive system (Fig.
9A
) with a long, narrow, curved ampulla that connects with the female gland complex and an elongate prostate. The prostate is as wide as the ampulla but narrows substantially before expanding into the short, curved, narrow deferent duct. The deferent duct is much narrower than the prostate. The penis is unarmed. The vagina is very elongate and wide distally, several times wider than the deferent duct, narrowing considerably proximally and connecting directly to the irregular bursa copulatrix. The oval seminal receptacle also connects to the bursa copulatrix next to the vaginal connection, and the short uterine duct that enters the female gland complex. The bursa copulatrix is ~ 3
x
as large as the seminal receptable. A large accessory gland connects to a narrow and convoluted duct that opens into the genital atrium, where a curved, sharp stylet is located.
Figure 9.
Drawings of the reproductive systems of specimens of the genus
Jorunna
Bergh, 1876
A
Jorunna daoulasi
sp. nov., MNHN IM-2013-86219
B
Jorunna hervei
sp. nov., MNHN IM-2013-86226. Abbreviations: ag, accessory gland; am, ampulla; bc, bursa copulatrix; dd, deferent duct; fg, female gland complex; pr, prostate; sr, seminal receptacle; st, stylet; vg, vagina.
Radular formula 24
x
n.0.n in a 26-mm long specimen (MNHN IM-2013-86220) and 25
x
n.0.n in a 27-mm long specimen (MNHN IM-2013-86219). Rachidian teeth absent. Innermost lateral teeth wide, having a short cusp with four or five irregular denticles (Fig.
10A
). Mid-lateral teeth hamate, lacking denticles (Fig.
10A
). The teeth increase in size gradually towards the distal portion of the half-row (Fig.
10B
). Outermost teeth very elongate, longer than mid-lateral teeth, with several elongate apical denticles (Fig.
10B
). No jaws ware observed.
Figure 10.
SEM of the radula of specimens of the genus
Jorunna
Bergh, 1876
A, B
Jorunna daoulasi
sp. nov., MNHN IM-2013-86220, innermost teeth (
A
), outer lateral teeth (
B
)
C-E
Jorunna hervei
sp. nov., MNHN IM-2013-86224, innermost teeth (
C
), mid-lateral teeth (
D
), outer lateral teeth (
E
).
Biology.
Range includes New Caledonia and possibly Papua New Guinea and Japan (see Remarks section below); uncommon, found at ~ 6 m depth on an unidentified grey sponge on which it is highly cryptic. All the specimens were found directly on the sponges while SCUBA diving.
Etymology.
This species is named after Alain Daoulas, outstanding collector and naturalist, who participated in two of the Koumac expeditions, collecting a number of important specimens.
Remarks.
Jorunna daoulasi
sp. nov. is placed in the genus
Jorunna
because it fits morphologically within the diagnoses of the genus provided by
Valdes
and Gosliner (2001)
and
Camacho-Garcia
and Gosliner (2008)
. Specifically,
J. daoulasi
sp. nov. has a soft mantle covered with long caryophyllidia, the radular teeth are hamate, and the reproductive system has an accessory gland and a copulatory stylet. Finally, in the molecular phylogenetic analyses,
J. daoulasi
sp. nov. is a member of a well-supported clade containing other members of
Jorunna
.
Camacho-Garcia
and Gosliner (2008)
provided a comprehensive revision and illustrations of the valid species of the genus
Jorunna
, including all the Indo-Pacific taxa described to date. None of the species included in
Camacho-Garcia
and
Gosliner's
(2008)
monograph have a similar color pattern and morphology to
J. daoulasi
sp. nov. Since then, several additional new species have been described from the Atlantic Ocean (
Edmunds 2011
;
Alvim and Pimenta 2013
;
Ortea et al. 2014
;
Ortea and Moro 2016
;
Neuhaus et al. 2021
) and the Indian Ocean (
Tibirica
et al. 2023
), but they are also morphologically and/or genetically different from
J. daoulasi
sp. nov. The most similar species to
J. daoulasi
sp. nov. in external morphology are
Jorunna
sp. 10 from Papua New Guinea illustrated by
Gosliner et al. (2018)
and
Rostanga
sp. 4 from Japan illustrated by
Nakano (2018)
, which have a very similar body shape and color and could represent the same species.