A phylogenetic analysis and systematic revision of the cryptobranch dorids (Mollusca, Nudibranchia, Anthobranchia)
Author
Valdés, Ángel
text
Zoological Journal of the Linnean Society
2002
2002-12-31
136
4
535
636
https://academic.oup.com/zoolinnean/article-lookup/doi/10.1046/j.1096-3642.2002.00039.x
journal article
5419
10.1046/j.1096-3642.2002.00039.x
8acc9095-eaff-47d7-b3da-91b6c2fb636e
0024-4082
4634200
GENUS
THORDISA
BERGH, 1877
Thordisa
Bergh, 1877a: 540
. Type species:
Thordisa maculigera
Bergh, 1877
, by subsequent designation by
Bergh (1905)
.
Etidoris
Ihering, 1886: 234
. Type species:
Etidoris ladislavii
Ihering, 1886
, by monotypy.
Nuvuca
Marcus & Marcus, 1967a: 621
. Type species:
Nuvuca lurca
Ev. Marcus & Er.
Marcus, 1967
, by original designation,
syn. nov.
Pupsikus
Marcus & Marcus, 1970a: 167–168
. Type species:
Pupsikus pinguis
Er. Marcus & Ev.
Marcus 1970
, by original designation,
syn. nov.
Diagnosis
Dorsum covered with soft, elongate tubercles. Head with two conical oral tentacles. Anterior border of the foot grooved and notched. Labial cuticle smooth, lacking rodlets. Radula composed of simple, hamate teeth. Outermost lateral teeth multidenticulate. Reproductive system with a flattened, granular prostate, having two well differentiated regions. Penis armed or not with hooks. One or more accessory glands present, having one or more associated copulatory spines.
Figure 19.
Discodoris ketos
(CASIZ 081808), SEM images of the radula, jaws and dorsal tubercles. A, inner lateral teeth; scale bar = 75 Mm. B, mid-lateral teeth; scale bar = 71 Mm. C, outer lateral teeth; scale bar = 42 Mm. D, dorsal tubercles; scale bar = 750 Mm. E, jaw elements; scale bar = 30 Mm.
Figure 20.
Discodoris ketos
(CASIZ 081808). A, general view of the anatomy; scale bar = 1 mm. B, reproductive system; scale bar = 1 mm. C, lateral view of the buccal bulb; scale bar = 1 mm. D, central nervous system; scale bar = 0.5 mm. E, ventral view of the mouth area; scale bar = 2 mm.
Remarks
Bergh (1877a)
described the genus
Thordisa
based on
Thordisa maculigera
Bergh, 1877
, but at the same time mentioned that
Doris villosa
Alder & Hancock, 1864
, also belongs to this genus. According to
Bergh (1877a)
the main distinctive feature of this genus is the presence of elongate tubercles on the dorsum and pectinate outermost lateral teeth.
Bergh (1891)
regarded
Etidoris
Ihering, 1886
as a synonym of
Thordisa
.
Bergh (1905)
added the new species
T. carinata
Bergh, 1905
,
T. tristis
,
T. hilaris
and with a question mark
T. maculosa
to the list of species of
Thordisa
, and designated
T. maculigera
as the
type
species.
The genus
Nuvuca
was described by
Marcus & Marcus (1967a)
on the basis of a single specimen of the new species
Nuvuca lurca
Ev. Marcus & Er.
Marcus, 1967
. According to these authors, the diagnostic features of this genus are: strongly spiculate body, unequal papillae on the dorsum, smooth labial cuticle, inner radular teeth with a short base and long cusp and pectinate outer teeth; a dart or copulatory spine joined to the male atrium; penis unarmed. Examination of the
holotype
of the type species revealed the presence of large dorsal papillae similar to those present in other species of
Thordisa
. The only remarkable difference between
Nuvuca
and
Thoridisa
is the absence of jaws in the former. This could be due to either interspecific variation or to Marcus & Marcus’s (1967a) neglecting to find this structure. Unfortunately, the parts of the foregut of the
holotype
dissected by Marcus & Marcus are not preserved with the rest of the specimen, and re-examination is not possible. Because the rest of the external and anatomical features of
Nuvuca
are identical to those of
Thordisa
, they are here regarded as synonyms.
Marcus & Marcus (1970a)
described the genus
Pupsikus
based on the new species
Pupsikus pinguis
Ev. Marcus & Er.
Marcus, 1970
. According to these authors,
Pupsikus
is characterized by having a ridge connecting the tentacles with the foot, labial armature with rodlets and ‘a radula containing denticulate lateral and feathered marginal teeth’. The prostate is voluminous, the penis is armed with hooks and there is an accessory gland with a copulatory spine. The ridges that connect the oral tentacles and the foot in the single preserved specimen examined by
Marcus & Marcus (1970a)
, are probably an artifact of observation. A re-examination of the
holotype
has revealed an oral morphology similar to that of other cryptobranch dorids. No trace of the ridge mentioned by
Marcus & Marcus (1970a)
has been found. The specimen was dissected and no anatomical information could be extracted from it, but the drawings and descriptions of
Marcus & Marcus (1970a)
are sufficient to identify it as a member of the genus
Thordisa
.